A crusher is a machine designed to reduce large rocks into smaller rocks, gravel , sand or rock dust.
135-468: Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled , or to reduce the size of a solid mix of raw materials (as in rock ore ), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in
270-411: A materials recovery facility , the materials must be sorted. This is done in a series of stages, many of which involve automated processes, enabling a truckload of material to be fully sorted in less than an hour. Some plants can now sort materials automatically; this is known as single-stream recycling . Automatic sorting may be aided by robotics and machine learning. In plants, a variety of materials
405-518: A century later relocated to Bristol where he had established a building brass and bronze industry by importing Dutch workers and using them to raid Dutch techniques. Both materials were considered superior to iron for cannon, and machines as they were better understood. But Darby would change the world in several key ways. Where the Dutch had failed in casting iron, one of Darby's apprentices, John Thomas succeeded in 1707 and as Burke put it: "had given England
540-582: A certain amount of spending for recycled products; or "price preference" programs that provide larger budgets when recycled items are purchased. Additional regulations can target specific cases: in the United States, for example, the Environmental Protection Agency mandates the purchase of oil, paper, tires and building insulation from recycled or re-refined sources whenever possible. The final government regulation toward increased demand
675-445: A common practice for most of human history with recorded advocates as far back as Plato in the fourth century BC. During periods when resources were scarce, archaeological studies of ancient waste dumps show less household waste (such as ash, broken tools, and pottery), implying that more waste was recycled in place of new material. However, archaeological artefacts made from recyclable material, such as glass or metal, may neither be
810-431: A concave surface and a conical head; both surfaces are typically lined with manganese steel surfaces. The inner cone has a slight circular movement, but does not rotate; the movement is generated by an eccentric arrangement. As with the jaw crusher, material travels downward between the two surfaces being progressively crushed until it is small enough to fall out through the gap between the two surfaces. A gyratory crusher
945-451: A crusher to reduce oversize material too large for a crusher. Crushers are used to reduce particle size enough so that the material can be processed into finer particles in a grinder. A typical processing line at a mine might consist of a crusher followed by a SAG mill followed by a ball mill . In this context, the SAG mill and ball mill are considered grinders rather than crushers. In operation,
1080-574: A form of recycling. Materials for recycling are either delivered to a household recycling center or picked up from curbside bins, then sorted, cleaned, and reprocessed into new materials for manufacturing new products. In ideal implementations, recycling a material produces a fresh supply of the same material—for example, used office paper would be converted into new office paper, and used polystyrene foam into new polystyrene. Some types of materials, such as metal cans , can be remanufactured repeatedly without losing their purity. With other materials, this
1215-445: A hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. Melting is performed in a furnace . Virgin material, external scrap, internal scrap, and alloying elements are used to charge
1350-399: A jagged and uneven surface. Applying surface force ( pressure ) results in unpredictable and typically non-cubical resulting particles. Utilizing velocity rather than surface force allows the breaking force to be applied evenly both across the surface of the rock as well as through the mass of the rock. Rock, regardless of size, has natural fissures (faults) throughout its structure. As rock
1485-500: A material. Heat treatment techniques include annealing , case-hardening , precipitation strengthening , tempering , and quenching . Although the term "heat treatment" applies only to processes where the heating and cooling are done for the specific purpose of altering properties intentionally, heating and cooling often occur incidentally during other manufacturing processes such as hot forming or welding. After degating and heat treating, sand or other molding media may remain adhered to
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#17330848258961620-430: A mold yields leftover metal — including heads, risers, and sprue (sometimes collectively called sprue) — that can exceed 50% of the metal required to pour a full mold. Since this metal must be remelted as salvage, the yield of a particular gating configuration becomes an important economic consideration when designing various gating schemes, to minimize the cost of excess sprue, and thus overall melting costs. Heat treating
1755-471: A more flexible option: Industries can meet their recycling targets at any point of their operations, or even contract out recycling in exchange for tradable credits. Opponents to these methods cite their large increase in reporting requirements, and claim that they rob the industry of flexibility. Governments have used their own purchasing power to increase recycling demand through "procurement policies". These policies are either "set-asides", which reserve
1890-418: A pick. Economies of scale gradually infused industrial enterprises, while transport became a key bottleneck as the volume of moved materials continued to increase following demand. This spurred numerous canal projects, inspired laying first wooden, then iron protected rails using draft animals to pull loads in the emerging bulk goods transportation dependent economy. In the coal industry, which grew as coal became
2025-405: A positive effect on the supply of recyclates when it specifies how and where the product can be recycled. "Recyclate" is a raw material sent to and processed in a waste recycling plant or materials-recovery facility so it can be used in the production of new materials and products. For example, plastic bottles can be made into plastic pellets and synthetic fabrics . The quality of recyclates
2160-625: A road surface. This removes the need for hauling oversized material to a stationary crusher and then back to the road surface. Additionally, Small/Mini Crushers (approx 6,000 to 60,000 pound range) are portable crushers typically used by travelling from jobsite-to-jobsite. These small crusher may be track or wheel mounted, gas, diesel, or electrically powered, but are primarily of the Jaw Crusher variety. The following table describes typical uses of commonly used crushers: A jaw crusher uses compressive force for breaking of particle. This mechanical pressure
2295-424: A single piece or solid pattern. More complex designs are made in two parts, called split patterns. A split pattern has a top or upper section, called a cope, and a bottom or lower section called a drag. Both solid and split patterns can have cores inserted to complete the final part shape. Cores are used to create hollow areas in the mold that would otherwise be impossible to achieve. Where the cope and drag separates
2430-433: A stable supply. The post-processed material can then be sold. If profitable, this conserves the emission of greenhouse gases; if unprofitable, it increases their emission. Buy-back centres generally need government subsidies to be viable. According to a 1993 report by the U.S. National Waste & Recycling Association , it costs an average $ 50 to process a ton of material that can be resold for $ 30. Drop-off centers require
2565-426: A steel foundry will use an EAF or induction furnace. Bronze or brass foundries use crucible furnaces or induction furnaces. Most aluminium foundries use either electric resistance or gas heated crucible furnaces or reverberatory furnaces. Degassing is a process that may be required to reduce the amount of hydrogen present in a batch of molten metal. Gases can form in metal castings in one of two ways: Hydrogen
2700-550: A turnover of €24 billion. EU countries are mandated to reach recycling rates of at least 50%; leading countries are already at around 65%. The overall EU average was 39% in 2013 and is rising steadily, to 45% in 2015. In 2015, the United Nations General Assembly set 17 Sustainable Development Goals . Goal 12, Responsible Consumption and Production , specifies 11 targets "to ensure sustainable consumption and production patterns". The fifth target, Target 12.5 ,
2835-530: Is 'thrown' by a VSI rotor against a solid anvil, it fractures and breaks along these fissures. Final particle size can be controlled by 1) the velocity at which the rock is thrown against the anvil and 2) the distance between the end of the rotor and the impact point on the anvil. The product resulting from VSI crushing is generally of a consistent cubical shape such as that required by modern Superpave highway asphalt applications. Using this method also allows materials with much higher abrasiveness to be crushed than
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#17330848258962970-401: Is a common contaminant for most cast metals. It forms as a result of material reactions or from water vapor or machine lubricants. If the hydrogen concentration in the melt is too high, the resulting casting will be porous; the hydrogen will exit the molten solution, leaving minuscule air pockets, as the metal cools and solidifies. Porosity often seriously deteriorates the mechanical properties of
3105-510: Is a compact geometry and size which is valuable in mining industry, .e.g. in underground hard-rock mining . A crusher bucket is an attachment for hydraulic excavators. Its way of working consists on a bucket with two crushing jaws inside, one of them is fixed and the other one moves back and forth relative to it, as in a jaw crusher . They are manufactured with a high inertia power train, circular jaw movement and an anti-stagnation plate, which prevents large shredding pieces from getting stuck in
3240-416: Is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of
3375-410: Is achieved by the two jaws of the crusher of which one is fixed while the other reciprocates. A jaw or toggle crusher consists of a set of vertical jaws, one jaw is kept stationary and is called a fixed jaw while the other jaw called a swing jaw, moves back and forth relative to it, by a cam or pitman mechanism, acting like a class II lever or a nutcracker . The volume or cavity between the two jaws
3510-444: Is applied to cement mill, mining, building construction, road &bridge construction, railway construction and metallurgy and some other industries. Multi-cylinder hydraulic cone crusher is mainly composed of main frame, eccentric shaft, crushing cone, mantle, bowl liner, adjusting device, dust ring, transmission device, bowl-shaped bearing, adjusting sleeve, hydraulic control system, hydraulic safety system, etc. The electric motor of
3645-519: Is applied to medium crushing. The medium type is applied to fine crushing. The short head type is applied to coarse fine crushing. As casting steel technique is adopted, the machine has good rigidity and large high strength. Single cylinder hydraulic cone crusher is mainly composed of main frame, transmission device, eccentric shaft, bowl-shaped bearing, crushing cone, mantle, bowl liner, adjusting device, adjusting sleeve, hydraulic control system, hydraulic safety system, dust-proof ring, feed plate, etc. It
3780-463: Is called the parting line . When making a pattern it is best to taper the edges so that the pattern can be removed without breaking the mold. This is called draft . The opposite of draft is an undercut where there is part of the pattern under the mold material, making it impossible to remove the pattern without damaging the mold. The pattern is made of wax, wood, plastic, or metal. The molds are constructed by several different processes dependent upon
3915-664: Is called the crushing chamber. The movement of the swing jaw can be quite small, since complete crushing is not performed in one stroke. The inertia required to crush the material is provided by a flywheel that moves a shaft creating an eccentric motion that causes the closing of the gap. Jaw crushers are heavy duty machines and hence need to be robustly constructed. The outer frame is generally made of cast iron or steel. The jaws themselves are usually constructed from cast steel. They are fitted with replaceable liners which are made of manganese steel, or Ni-hard (a Ni-Cr alloyed cast iron). Jaw crushers are usually constructed in sections to ease
4050-428: Is capable with an HSI and most other crushing methods. VSI crushers generally utilize a high speed spinning rotor at the center of the crushing chamber and an outer impact surface of either abrasive resistant metal anvils or crushed rock. Utilizing cast metal surfaces 'anvils' is traditionally referred to as a "shoe and anvil VSI". Utilizing crushed rock on the outer walls of the crusher for new rock to be crushed against
4185-567: Is common to paint castings to prevent corrosion and improve visual appeal. Some foundries assemble castings into complete machines or sub-assemblies. Other foundries weld multiple castings or wrought metals together to form a finished product. More and more, finishing processes are being performed by robotic machines, which eliminate the need for a human to physically grind or break parting lines, gating material, or feeders. Machines can reduce risk of injury to workers and lower costs for consumables — while also increasing productivity. They also limit
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4320-474: Is defined as substantially reducing waste generation by 2030, indicated by the National Recycling Rate. In 2018, changes in the recycling industry have sparked a global "crisis". On 31 December 2017, China announced its " National Sword " policy, setting new standards for imports of recyclable material and banning materials deemed too "dirty" or "hazardous". The new policy caused drastic disruptions in
4455-546: Is dependent on the alloy system quantities produced. For ferrous materials EAFs, cupolas, and induction furnaces are commonly used. Reverberatory and crucible furnaces are common for producing aluminium, bronze, and brass castings. Furnace design is a complex process, and the design can be optimized based on multiple factors. Furnaces in foundries can be any size, ranging from small ones used to melt precious metals to furnaces weighing several tons, designed to melt hundreds of pounds of scrap at one time. They are designed according to
4590-621: Is helping increase slag utilization, hence reducing wastage and pollution. Economist Steven Landsburg , author of a paper entitled "Why I Am Not an Environmentalist", claimed that paper recycling actually reduces tree populations. He argues that because paper companies have incentives to replenish their forests, large demands for paper lead to large forests while reduced demand for paper leads to fewer "farmed" forests. When foresting companies cut down trees, more are planted in their place; however, such farmed forests are inferior to natural forests in several ways. Farmed forests are not able to fix
4725-445: Is likely to be recycled, so higher amounts of non-target and non-recyclable materials can reduce the quantity of recycled products. A high proportion of non-target and non-recyclable material can make it more difficult to achieve "high-quality" recycling; and if recyclate is of poor quality, it is more likely to end up being down-cycled or, in more extreme cases, sent to other recovery options or landfilled . For example, to facilitate
4860-497: Is mainly used in mining, chemical industry, road and bridge construction, building, etc. As for VSC series cone crusher, there are four crushing cavities (coarse, medium, fine and superfine) to choose. Compared with the same type, VSC series cone crusher, whose combination of crushing frequency and eccentricity is the best, can make materials have higher comminution degree and higher yield. In addition, VSC series cone crusher's enhanced laminating crushing effect on material particles makes
4995-587: Is often difficult or too expensive (compared with producing the same product from raw materials or other sources), so "recycling" of many products and materials involves their reuse in producing different materials (for example, paperboard ). Another form of recycling is the salvage of constituent materials from complex products, due to either their intrinsic value (such as lead from car batteries and gold from printed circuit boards ), or their hazardous nature (e.g. removal and reuse of mercury from thermometers and thermostats ). Reusing materials has been
5130-399: Is one of the main types of primary crushers in a mine or ore processing plant. Gyratory crushers are designated in size either by the gape and mantle diameter or by the size of the receiving opening. Gyratory crushers can be used for primary or secondary crushing. The crushing action is caused by the closing of the gap between the mantle line (movable) mounted on the central vertical spindle and
5265-420: Is one of the principal challenges for the success of a long-term vision of a green economy and achieving zero waste . It generally refers to how much of it is composed of target material, versus non-target material and other non-recyclable material. Steel and other metals have intrinsically higher recyclate quality; it is estimated that two-thirds of all new steel comes from recycled steel. Only target material
5400-533: Is rarely harvested for paper because of their heterogeneity. According to the United Nations Framework Convention on Climate Change secretariat, the overwhelming direct cause of deforestation is subsistence farming (48% of deforestation) and commercial agriculture (32%), which is linked to food, not paper production. Other non-conventional methods of material recycling, like Waste-to-Energy (WTE) systems, have garnered increased attention in
5535-431: Is recycled product labeling. When producers are required to label their packaging with the amount of recycled material it contains (including the packaging), consumers can make more educated choices. Consumers with sufficient buying power can choose more environmentally conscious options, prompting producers to increase the recycled material in their products and increase demand. Standardized recycling labeling can also have
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5670-676: Is regarded as waste. Environmental impact of slag include copper paralysis , which leads to death due to gastric hemorrhage, if ingested by humans. It may also cause acute dermatitis upon skin exposure. Toxicity may also be uptaken by crops through soil, consequently spreading animals and food sources and increasing the risk of cardiovascular diseases, cancer, cognitive impairment, chronic anemia, and damage to kidneys, bones, nervous system, brain and skin. Substituting gravel and grit in quarries has been more cost-effective, due to having its sources with better proximity to consumer markets. Trading between countries and establishment of blast furnaces
5805-444: Is similar in operation to a gyratory crusher, with less steepness in the crushing chamber and more of a parallel zone between crushing zones. A cone crusher breaks rock by squeezing the rock between an eccentrically gyrating spindle, which is covered by a wear-resistant mantle, and the enclosing concave hopper, covered by a manganese concave or a bowl liner. As rock enters the top of the cone crusher, it becomes wedged and squeezed between
5940-649: Is sorted including paper, different types of plastics, glass, metals, food scraps, and most types of batteries . A 30% increase in recycling rates has been seen in areas with these plants. In the US, there are over 300 materials recovery facilities. Initially, commingled recyclates are removed from the collection vehicle and placed on a conveyor belt spread out in a single layer. Large pieces of corrugated fiberboard and plastic bags are removed by hand at this stage, as they can cause later machinery to jam. Next, automated machinery such as disk screens and air classifiers separate
6075-578: Is the other extreme, where each material is cleaned and sorted prior to collection. It requires the least post-collection sorting and produces the purest recyclates. However, it incurs additional operating costs for collecting each material, and requires extensive public education to avoid recyclate contamination . In Oregon , USA, Oregon DEQ surveyed multi-family property managers; about half of them reported problems, including contamination of recyclables due to trespassers such as transients gaining access to collection areas. Source separation used to be
6210-626: Is the third component of the " Reduce , Reuse , and Recycle" waste hierarchy . It promotes environmental sustainability by removing raw material input and redirecting waste output in the economic system. There are some ISO standards related to recycling, such as ISO 15270:2008 for plastics waste and ISO 14001 :2015 for environmental management control of recycling practice. Recyclable materials include many kinds of glass, paper, cardboard, metal, plastic, tires , textiles , batteries, and electronics . The composting and other reuse of biodegradable waste —such as food and garden waste —is also
6345-541: Is then removed from its mold. Where the mold is sand based, this can be done by shaking or tumbling. This frees the casting from the sand, which is still attached to the metal runners and gates — which are the channels through which the molten metal traveled to reach the component itself. Degating is the removal of the heads, runners, gates, and risers from the casting. Runners, gates, and risers may be removed using cutting torches , bandsaws , or ceramic cutoff blades. For some metal types, and with some gating system designs,
6480-448: Is traditionally referred to as "rock on rock VSI". VSI crushers can be used in static plant set-up or in mobile tracked equipment. Mineral sizers are a variety of roll crushers which use two rotors with large teeth, on small diameter shafts, driven at a low speed by a direct high torque drive system. This design produced three-stage breaking action which all interact when breaking materials using sizer technology. Their primary advantage
6615-451: Is treated using inferior activities, it can release as many as 1000 different chemical substances ... including harmful neurotoxicants such as lead .” A paper in the journal Sustainable Materials & Technologies remarks upon the difficulty of managing e-waste, particularly from home automation products, which, due to their becoming obsolete at a high rate, are putting increasing strain on recycling systems, which have not adapted to meet
6750-402: Is useful as it assists in pushing the particles through the crushing chamber. This phenomenon leads to higher capacity of the single toggle jaw crushers but it also results in higher wear of the crushing jaws. These type of jaw crushers are preferred for the crushing of softer particles. In the double toggle jaw crushers, the oscillating motion of the swing jaw is caused by the vertical motion of
6885-614: The 1970s due to rising energy costs. Recycling aluminium uses only 5% of the energy of virgin production. Glass, paper and other metals have less dramatic but significant energy savings when recycled. Although consumer electronics have been popular since the 1920s, recycling them was almost unheard of until early 1991. The first electronic waste recycling scheme was implemented in Switzerland , beginning with collection of old refrigerators, then expanding to cover all devices. When these programs were created, many countries could not deal with
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#17330848258967020-412: The advantage of reliable construction, high productivity, better granularity and shape of finished products, easy adjustment and lower operational costs. The spring release system of a cone crusher acts an overload protection that allows tramp to pass through the crushing chamber without damage to the crusher. Compound cone crusher (VSC series cone crusher) can crush materials of over medium hardness . It
7155-569: The amount of material being removed. These steps are done prior to any final machining. After grinding, any surfaces that require tight dimensional control are machined. Many castings are machined in CNC milling centers. The reason for this is that these processes have better dimensional capability and repeatability than many casting processes. However, it is not uncommon today for castings to be used without machining. A few foundries provide other services before shipping cast products to their customers. It
7290-489: The application of force concentrated in the tip of the miners pick or sledge hammer driven drill bit. Before explosives came into widespread use in bulk mining in the mid-nineteenth century, most initial ore crushing and sizing was by hand and hammers at the mine or by water powered trip hammers in the small charcoal fired smithies and iron works typical of the Renaissance through the early-to-middle Industrial Revolution . It
7425-506: The application of these machines. Mobile crushers are versatile and efficient machines designed for on-site crushing in mining and construction, offering flexibility and mobility to process materials directly at the job site. Mobile crushers are available in various types and configurations: Mobile Jaw Crushers: These crushers feature a stationary jaw and a movable jaw, enabling primary crushing of materials with varying hardness and abrasiveness. Mobile Impact Crushers: Impact crushers utilize
7560-559: The armorers of the European continent's powers by having been leading producers of brass and bronze guns, and eventually by various acts of Parliament, gradually banned or restricted the further cutting of trees for charcoal in larger and larger regions in the United Kingdom. In 1611, a consortium led by courtier Edward Zouch was granted a patent for the reverberatory furnace , a furnace using coal, not precious national timber reserves, which
7695-402: The basic methods of material size reduction; impact, compression, attrition, and cutting. Depending on the material properties and desired outcome some methods of crushing and thus machines designs may be more appropriate for the use case. Typically, crushing stages are followed by milling stages if the materials need to be further reduced. Additionally rock breakers are typically located next to
7830-590: The blocks in the crushing chamber when the machine is suddenly stuffy. Thus the maintenance rate is greatly reduced and production efficiency is greatly improved as it can remove blocks without disassembling the machine. Impact crushers involve the use of impact rather than pressure to crush material. The material is contained within a cage, with openings on the bottom, end, or side of the desired size to allow pulverized material to escape. There are two types of impact crushers: horizontal shaft impactor and vertical shaft impactor. The HSI crushers break rock by impacting
7965-540: The bucket's mouth, not allowing them to enter the crushing jaws. They have also the crushing jaws placed in a cross position. This position together with its circular motion gives these crusher buckets the faculty of grinding wet material. For the most part advances in crusher design have moved slowly. Jaw crushers have remained virtually unchanged for sixty years. More reliability and higher production have been added to basic cone crusher designs that have also remained largely unchanged. Increases in rotating speed have provided
8100-621: The cans that is repulsed by a large magnetic field , ejecting the cans from the stream. Foundry A foundry is a factory that produces metal castings . Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron . However, other metals, such as bronze , brass , steel , magnesium , and zinc , are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed. Foundries are one of
8235-436: The casting surface. Numerous materials may be used to clean cast surfaces, including steel, iron, other metal alloys, aluminium oxides, glass beads, walnut shells, baking powder, and many others. The blasting media is selected to develop the color and reflectance of the cast surface. Terms used to describe this process include cleaning, bead blasting, and sand blasting . Shot peening may be used to further work-harden and finish
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#17330848258968370-423: The casting. To remove any mold remnants, the surface is cleaned using a blasting process. This means a granular media will be propelled against the surface of the casting to mechanically knock away the adhering sand. The media may be blown with compressed air, or may be hurled using a shot wheel. The cleaning media strikes the casting surface at high velocity to dislodge the mold remnants (for example, sand, slag) from
8505-491: The compaction of materials can also make this more difficult. Despite improvements in technology and quality of recyclate, sorting facilities are still not 100% effective in separating materials. When materials are stored outside, where they can become wet, can also cause problems for re-processors. Further sorting steps may be required to satisfactorily reduce the amount of non-target and non-recyclable material. A number of systems have been implemented to collect recyclates from
8640-411: The concave liners (fixed) mounted on the main frame of the crusher. The gap is opened and closed by an eccentric on the bottom of the spindle that causes the central vertical spindle to gyrate. The vertical spindle is free to rotate around its own axis. The crusher illustrated is a short-shaft suspended spindle type, meaning that the main shaft is suspended at the top and that the eccentric is mounted above
8775-435: The cone crusher drives the eccentric shaft to make periodic swing movement under the shaft axis, and consequently surface of mantle approaches and leaves the surface of bowl liner now and then, so that the material is crushed due to squeezing and grinding inside the crushing chamber. The safety cylinder of the machine can ensure safety as well as lift supporting sleeve and static cone by a hydraulic system and automatically remove
8910-572: The container is returned to a collection point. These programs have succeeded in creating an average 80% recycling rate. Despite such good results, the shift in collection costs from local government to industry and consumers has created strong opposition in some areas —for example, where manufacturers bear the responsibility for recycling their products. In the European Union, the WEEE Directive requires producers of consumer electronics to reimburse
9045-499: The crisis. According to the WHO (2023), “Every year millions of electrical and electronic devices are discarded ... a threat to the environment and to human health if they are not treated, disposed of, and recycled appropriately. Common items ... include computers ... e-waste are recycled using environmentally unsound techniques and are likely stored in homes and warehouses, dumped, exported or recycled under inferior conditions. When e-waste
9180-420: The crusher. In many countries, the lifting tool is mandatory due to legislative and policy-based safety requirements. Recycled This is an accepted version of this page Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials . The recyclability of a material depends on its ability to reacquire
9315-424: The crushing chamber. Foreign objects, such as steel , can cause extensive damage to a cone crusher, and additional costs in lost production. The advance of hydraulic relief systems has greatly reduced downtime and improved the life of these machines. Due to safety requirements and the weight of the jaws, many companies and OEM providers have produced a suite of lifting tools to safely install and fit these tools into
9450-419: The cubic shape of crushed materials better, which increases the selling point. Symons cone crusher (spring cone crusher) can crush materials of above medium hardness. And it is widely used in metallurgy, building, hydropower, transportation, chemical industry, etc. When used with jaw crusher, it can be used as secondary, tertiary or quaternary crushing. Generally speaking, the standard type of Symons cone crusher
9585-474: The degree to which they fragment the starting material, with primary and secondary crushers handling coarse materials, and tertiary and quaternary crushers reducing ore particles to finer gradations. Each crusher is designed to work with a certain maximum size of raw material, and often delivers its output to a screening machine which sorts and directs the product for further processing. As well as size, machines designed for each of these stages must take into account
9720-417: The demand for recycled materials: minimum recycled content mandates, utilization rates, procurement policies, and recycled product labeling . Both minimum recycled content mandates and utilization rates increase demand by forcing manufacturers to include recycling in their operations. Content mandates specify that a certain percentage of a new product must consist of recycled material. Utilization rates are
9855-580: The early 19th century to at least 1914. Industrialization spurred demand for affordable materials. In addition to rags, ferrous scrap metals were coveted as they were cheaper to acquire than virgin ore. Railroads purchased and sold scrap metal in the 19th century, and the growing steel and automobile industries purchased scrap in the early 20th century. Many secondary goods were collected, processed and sold by peddlers who scoured dumps and city streets for discarded machinery, pots, pans, and other sources of metal. By World War I , thousands of such peddlers roamed
9990-487: The entire casting manufacturing route. Casting process simulation was initially developed at universities starting from the early ' 70s , mainly in Europe and in the U.S. , and is regarded as the most important innovation in casting technology over the last 50 years. Since the late ' 80s , commercial programs (such as PoligonSoft, AutoCAST and Magma) are available which make it possible for foundries to gain new insight into what
10125-433: The facility. The process includes melting the charge, refining the melt, adjusting the melt chemistry and tapping into a transport vessel. Refining is done to remove harmful gases and elements from the molten metal to avoid casting defects. Material is added during the melting process to bring the final chemistry within a specific range specified by industry and/or internal standards. Certain fluxes may be used to separate
10260-420: The features of jaw and cone crushers, offering versatility and efficiency for processing diverse materials in various applications. VSI crushers use a different approach involving a high speed rotor with wear resistant tips and a crushing chamber designed to 'throw' the rock against. The VSI crushers utilize velocity rather than surface force as the predominant force to break rock. In its natural state, rock has
10395-403: The form that a certain percentage of a material must be diverted from the city's waste stream by a target date. The city is responsible for working to meet this target. Container deposit legislation mandates refunds for the return of certain containers—typically glass, plastic and metal. When a product in such a container is purchased, a small surcharge is added that the consumer can reclaim when
10530-401: The furnace must be designed for temperatures over 1,600 °C (2,910 °F). The fuel used to reach these high temperatures can be electricity (as employed in electric arc furnaces ) or coke . The majority of foundries specialize in a particular metal and have furnaces dedicated to these metals. For example, an iron foundry (for cast iron) may use a cupola , induction furnace, or EAF, while
10665-505: The furnace. Virgin material refers to commercially pure forms of the primary metal used to form a particular alloy . Alloying elements are either pure forms of an alloying element, like electrolytic nickel , or alloys of limited composition, such as ferroalloys or master alloys. External scrap is material from other forming processes such as punching , forging , or machining . Internal scrap consists of gates , risers , defective castings, and other extraneous metal oddments produced within
10800-600: The gear. The short-shaft design has superseded the long-shaft design in which the eccentric is mounted below the gear. With the rapid development of mining technology, the cone crusher can be divided into four types: compound cone crusher, spring cone crusher, hydraulic cone crusher and gyratory crusher. According to different models, the cone crusher is divided into vertical shaft cone (VSC) series cone crusher (compound cone crusher), Symons cone crusher, PY cone crusher, single cylinder hydraulic cone crusher, multi-cylinder hydraulic cone crusher, gyratory crusher, etc. A cone crusher
10935-423: The general waste stream, occupying different places on the spectrum of trade-off between public convenience and government ease and expense. The three main categories of collection are drop-off centers, buy-back centers and curbside collection. About two-thirds of the cost of recycling is incurred in the collection phase. Curbside collection encompasses many subtly different systems, which differ mostly on where in
11070-571: The global recycling market, and reduced the prices of scrap plastic and low-grade paper. Exports of recyclable materials from G7 countries to China dropped dramatically, with many shifting to countries in southeast Asia. This generated significant concern about the recycling industry's practices and environmental sustainability . The abrupt shift caused countries to accept more materials than they could process, and raised fundamental questions about shipping waste from developed countries to countries with few environmental regulations—a practice that predated
11205-458: The goals desired." Recycling—or "salvage", as it was then usually known—was a major issue for governments during World War II , where financial constraints and significant material shortages made it necessary to reuse goods and recycle materials. These resource shortages caused by the world wars , and other such world-changing events, greatly encouraged recycling. It became necessary for most homes to recycle their waste, allowing people to make
11340-562: The key to the Industrial Revolution" . At the time, mines and foundries were virtually all small enterprises except for the tin mines (driven by the price and utility of brass) and materials came out of the mines already hammered small by legions of miners who had to stuff their work into carry sacks for pack animal slinging. Concurrently, mines needed drainage resulting in Savery and Newcomen's early steam driven pumping systems. The deeper
11475-438: The large pieces to a size which can be handled by the downstream machinery. Some crushers are mobile and can crush rocks as large as 1.5 meter (60 inches). Primarily used in-pit at the mine face these units are able to move with the large infeed machines (mainly shovels) to increase the tonnage produced. In a mobile road operation, these crushed rocks are directly combined with concrete, and asphalt which are then deposited on to
11610-425: The larger operations became the coal breakers that fueled industrial growth from the first decade of the 1600s to the replacement of breakers in the 1970s through the fuel needs of the present day. The gradual coming of that era and displacement of the cottage industry based economies was itself accelerated first by the utility of wrought and cast iron as a desired materials giving impetus to larger operations, then in
11745-403: The largest contributors to the manufacturing recycling movement, melting and recasting millions of tons of scrap metal every year to create new durable goods. Moreover, many foundries use sand in their molding process. These foundries often use, recondition, and reuse sand, which is another form of recycling. In metalworking , casting involves pouring liquid metal into a mold , which contains
11880-470: The largest variation. For instance, a 48-inch (120 cm) cone crusher manufactured in 1960 may be able to produce 170 tons/h of crushed rock, whereas the same size crusher manufactured today may produce 300 tons/h. These production improvements come from speed increases and better crushing chamber designs. The largest advance in cone crusher reliability has been seen in the use of hydraulics to protect crushers from being damaged when uncrushable objects enter
12015-500: The late 19th century both invented new materials (e.g. Bakelite in 1907) and promised to transform valueless into valuable materials. Proverbially, you could not make a silk purse of a sow's ear —until the US firm Arthur D. Little published in 1921 "On the Making of Silk Purses from Sows' Ears", its research proving that when "chemistry puts on overalls and gets down to business [...] new values appear. New and better paths are opened to reach
12150-472: The late-sixteenth century by the increasing scarcity of wood lands for charcoal production to make the newfangled window glass material that had become—along with the chimney— 'all the rage' among the growing middle-class and affluence of the sixteenth-and-seventeenth centuries;and as always, the charcoal needed to smelt metals, especially to produce ever larger amounts of brass and bronze , pig iron , cast iron and wrought iron demanded by
12285-400: The mantle and the bowl liner or concave. Large pieces of ore are broken once, and then fall to a lower position (because they are now smaller) where they are broken again. This process continues until the pieces are small enough to fall through the narrow opening at the bottom of the crusher. A cone crusher is suitable for crushing a variety of mid-hard and above mid-hard ores and rocks. It has
12420-406: The material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of
12555-415: The material is crushed progressively smaller and smaller as it travels downward until it is small enough to escape from the bottom opening. The Dodge jaw crusher has a variable feed area and a fixed discharge area which leads to choking of the crusher and hence is used only for laboratory purposes and not for heavy duty operations. A gyratory crusher is similar in basic concept to a jaw crusher, consisting of
12690-498: The metal from slag and/or dross and degassers are used to remove dissolved gas from metals that readily dissolve in gasses. During the tap, final chemistry adjustments are made. Several specialised furnaces are used to heat the metal. Furnaces are refractory-lined vessels that contain the material to be melted and provide the energy to melt it. Modern furnace types include electric arc furnaces (EAF), induction furnaces , cupolas , reverberatory , and crucible furnaces. Furnace choice
12825-430: The metal. An efficient way of removing hydrogen from the melt is to bubble a dry, insoluble gas through the melt by purging or agitation. When the bubbles go up in the melt, they catch the dissolved hydrogen and bring it to the surface. Chlorine, nitrogen, helium and argon are often used to degas non-ferrous metals. Carbon monoxide is typically used for iron and steel. There are various types of equipment that can measure
12960-522: The mines went, the larger the demand became for better pumps, the greater the demand for iron, the greater the need for coal, the greater the demand for each. Seeing ahead clearly, Darby, sold off his brass business interests and relocated to Coalbrookdale with its plentiful coal mines, water power and nearby ore supplies. Over that decade his foundries developed iron casting technologies and began to supplant other metals in many applications. He adapted Coking of his fuel by copying Brewers practices. In 1822,
13095-599: The most of what was available. Recycling household materials also meant more resources were left available for war efforts. Massive government campaigns, such as the National Salvage Campaign in Britain and the Salvage for Victory campaign in the United States, occurred in every fighting nation, urging citizens to donate metal, paper, rags, and rubber as a patriotic duty. A considerable investment in recycling occurred in
13230-511: The new consumer classes. Other metallurgical developments such as silver and gold mining mirrored the practices and developments of the bulk material handling methods and technologies feeding the burgeoning appetite for more and more iron and glass, both of which were rare in personal possessions until the 1700s. Things only became worse when the English figured out how to cast the more economical iron cannons (1547), following on their feat of becoming
13365-520: The original object nor resemble it, with the consequence that a successful ancient recycling economy can become invisible when recycling is synonymous with re-melting rather than reuse. In pre-industrial times, there is evidence of scrap bronze and other metals being collected in Europe and melted down for continuous reuse. Paper recycling was first recorded in 1031 when Japanese shops sold repulped paper. In Britain dust and ash from wood and coal fires
13500-447: The pitman. The pitman moves up and down. The swing jaw closes, i.e., it moves towards the fixed jaw when the pitman moves upward and opens during the downward motion of the pitman. This type is commonly used in mines due to its ability to crush tough and abrasive materials. In the Dodge type jaw crushers, the jaws are farther apart at the top than at the bottom, forming a tapered chute so that
13635-489: The potential for human error and increase repeatability in the quality of grinding. Casting processes simulation uses numerical methods to calculate cast component quality considering mold filling, solidification and cooling, and provides a quantitative prediction of casting mechanical properties, thermal stresses and distortion. Simulation accurately describes a cast component's quality up-front before production starts. The casting rigging can be designed with respect to
13770-424: The preferred fuel for smelting ores, crushing and preparation (cleaning) was performed for over a hundred years in coal breakers , massive noisy buildings full of conveyors, belt-powered trip-hammer crushing stages and giant metal grading/sorting grates. Like mine pumps, the internal conveyors and trip-hammers were housed within these 7—11 storey buildings. Mining operations use crushers, commonly classified by
13905-407: The preferred method due to the high cost of sorting commingled (mixed waste) collection. However, advances in sorting technology have substantially lowered this overhead, and many areas that had developed source separation programs have switched to what is called co-mingled collection . At buy-back centers, separated, cleaned recyclates are purchased, providing a clear incentive for use and creating
14040-400: The presence of hydrogen. Alternatively, the presence of hydrogen can be measured by determining the density of a metal sample. In cases where porosity still remains present after the degassing process, porosity sealing can be accomplished through a process called metal impregnating . In the casting process, a pattern is made in the shape of the desired part. Simple designs can be made in
14175-617: The principle of rapid impact to crush materials, making them suitable for secondary and tertiary crushing of various rocks and minerals. Mobile Cone Crushers: Cone crushers employ a cone-shaped crushing chamber, ideal for producing finely crushed aggregates and sands for construction and mining applications. Mobile Vertical Shaft Impact (VSI) Crushers: VSI crushers utilize a high-speed rotor with wear-resistant tips to crush materials, offering superior shaping capabilities for producing high-quality aggregates with excellent particle shape. Mobile Jaw and Cone Combination Crushers: These crushers combine
14310-532: The process the recyclates are sorted and cleaned. The main categories are mixed waste collection, commingled recyclables, and source separation. A waste collection vehicle generally picks up the waste. In mixed waste collection, recyclates are collected mixed with the rest of the waste, and the desired materials are sorted out and cleaned at a central sorting facility. This results in a large amount of recyclable waste (especially paper) being too soiled to reprocess, but has advantages as well: The city need not pay for
14445-416: The process transportation if they are to be taken underground for carrying out the operations. Jaw crushers are classified on the basis of the position of the pivoting of the swing jaw The Blake crusher was patented by Eli Whitney Blake in 1858. The Blake type jaw crusher has a fixed feed area and a variable discharge area. Blake crushers are of two types- single toggle and double toggle jaw crushers. In
14580-442: The properties it had in its original state. It is an alternative to "conventional" waste disposal that can save material and help lower greenhouse gas emissions . It can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution (from incineration ) and water pollution (from landfilling ). Recycling is a key component of modern waste reduction and
14715-564: The properties of recycled waste plastic and sand bricks. The composite pavers can be sold at 100% profit while employing workers at 1.5× the minimum wage in the West African region, where distributed recycling has the potential to produce 19 million pavement tiles from 28,000 tons of plastic water sachets annually in Ghana , Nigeria , and Liberia . This has also been done with COVID19 masks. Once commingled recyclates are collected and delivered to
14850-462: The pumping industries needs for larger cylinders met up with Darby's ability to melt sufficient quantities of pig iron to cast large inexpensive iron cylinders instead of costly brass ones, reducing the cost of cylinders by nine-tenths. With gunpowder being increasingly applied to mining, rock chunks from a mining face became much larger, and the blast dependent mining itself had become dependent upon an organized group, not just an individual swinging
14985-402: The quality of final recyclate streams, and require extra efforts to discard those materials at later stages in the recycling process. Different collection systems can induce different levels of contamination. When multiple materials are collected together, extra effort is required to sort them into separate streams and can significantly reduce the quality of the final products. Transportation and
15120-446: The raw material (of various sizes) is usually delivered to the primary crusher's hopper by dump trucks , excavators or wheeled front-end loaders . A feeder device such as an apron feeder, conveyor or vibrating grid controls the rate at which this material enters the crusher, and often contains a preliminary screening device which allows smaller material to bypass the crusher itself, thus improving efficiency. Primary crushing reduces
15255-569: The recent past due to the polarizing nature of their emissions. While viewed as a sustainable method of capturing energy from material waste feedstocks by many, others have cited numerous explanations for why the technology has not been scaled globally. For a recycling program to work, a large, stable supply of recyclable material is crucial. Three legislative options have been used to create such supplies: mandatory recycling collection, container deposit legislation , and refuse bans. Mandatory collection laws set recycling targets for cities, usually in
15390-897: The recyclates by weight, splitting lighter paper and plastic from heavier glass and metal. Cardboard is removed from mixed paper, and the most common types of plastic— PET (#1) and HDPE (#2)—are collected, so these materials can be diverted into the proper collection channels. This is usually done by hand; but in some sorting centers, spectroscopic scanners are used to differentiate between types of paper and plastic based on their absorbed wavelengths. Plastics tend to be incompatible with each other due to differences in chemical composition ; their polymer molecules repel each other, similar to oil and water. Strong magnets are used to separate out ferrous metals such as iron, steel and tin cans . Non-ferrous metals are ejected by magnetic eddy currents : A rotating magnetic field induces an electric current around aluminum cans, creating an eddy current inside
15525-485: The recyclers' costs. An alternative way to increase the supply of recyclates is to ban the disposal of certain materials as waste, often including used oil , old batteries, tires , and garden waste. This can create a viable economy for the proper disposal of the products. Care must be taken that enough recycling services exist to meet the supply, or such bans can create increased illegal dumping . Four forms of legislation have also been used to increase and maintain
15660-409: The recycling needs posed by this type of product. Copper slag is obtained when copper and nickel ores are recovered from their source ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. An estimate of 2.2–3 tons of copper slag is generated per ton of copper produced, resulting in around 24.6 tons of slag per year, which
15795-582: The recycling process. The 2000s saw a boom in both the sales of electronic devices and their growth as a waste stream: In 2002, e-waste grew faster than any other type of waste in the EU. This spurred investment in modern automated facilities to cope with the influx, especially after strict laws were implemented in 2003. As of 2014, the European Union had about 50% of world share of waste and recycling industries, with over 60,000 companies employing 500,000 people and
15930-586: The remanufacturing of clear glass products, there are tight restrictions for colored glass entering the re-melt process. Another example is the downcycling of plastic, where products such as plastic food packaging are often downcycled into lower quality products, and do not get recycled into the same plastic food packaging. The quality of recyclate not only supports high-quality recycling, but it can also deliver significant environmental benefits by reducing, reusing, and keeping products out of landfills . High-quality recycling can support economic growth by maximizing
16065-413: The required component properties. This has benefits beyond a reduction in pre-production sampling, as the precise layout of the complete casting system also leads to energy , material, and tooling savings. The software supports the user in component design, the determination of melting practice and casting methoding through to pattern and mold making, heat treatment , and finishing. This saves costs along
16200-445: The rock with hammers that are fixed upon the outer edge of a spinning rotor. HSI machines are sold in stationary, trailer mounted and crawler mounted configurations. HSI's are used in recycling, hard rock and soft materials. In earlier years the practical use of HSI crushers is limited to soft materials and non abrasive materials, such as limestone , phosphate , gypsum , weathered shales , however improvements in metallurgy have changed
16335-428: The separate collection of recyclates, no public education is needed, and any changes to the recyclability of certain materials are implemented where sorting occurs. In a commingled or single-stream system , recyclables are mixed but kept separate from non-recyclable waste. This greatly reduces the need for post-collection cleaning, but requires public education on what materials are recyclable. Source separation
16470-537: The sheer quantity of e-waste , or its hazardous nature, and began to export the problem to developing countries without enforced environmental legislation. (For example, recycling computer monitors in the United States costs 10 times more than in China.) Demand for electronic waste in Asia began to grow when scrapyards found they could extract valuable substances such as copper , silver , iron , silicon , nickel , and gold during
16605-450: The single toggle jaw crushers, the swing jaw is suspended on the eccentric shaft which leads to a much more compact design than that of the double toggle jaw crusher. The swing jaw, suspended on the eccentric, undergoes two types of motion- swing motion towards the fixed jaw due to the action of toggle plate and vertical movement due to the rotation of the eccentric. These two motions, when combined, lead to an elliptical jaw motion. This motion
16740-486: The soil as quickly as natural forests. This can cause widespread soil erosion and often requiring large amounts of fertilizer to maintain the soil, while containing little tree and wild-life biodiversity compared to virgin forests. Also, the new trees planted are not as big as the trees that were cut down, and the argument that there would be "more trees" is not compelling to forestry advocates when they are counting saplings. In particular, wood from tropical rainforests
16875-444: The sprue, runners, and gates can be removed by breaking them away from the casting with a sledge hammer or specially designed knockout machinery. Risers must usually be removed using a cutting method (see above) but some newer methods of riser removal use knockoff machinery with special designs incorporated into the riser neck geometry that allow the riser to break off at the right place. The gating system required to produce castings in
17010-402: The stone provided a boost to muscle power, used against a stone anvil. Querns and mortars are types of these crushing devices. In industry, crushers are machines which use a metal surface to break or compress materials into small fractional chunks or denser masses. Throughout most of industrial history, the greater part of crushing and mining part of the process occurred under muscle power as
17145-667: The streets of American cities, taking advantage of market forces to recycle post-consumer materials into industrial production. Manufacturers of beverage bottles, including Schweppes , began offering refundable recycling deposits in Great Britain and Ireland around 1800. An official recycling system with refundable deposits for bottles was established in Sweden in 1884, and for aluminum beverage cans in 1982; it led to recycling rates of 84–99%, depending on type (glass bottles can be refilled around 20 times). New chemical industries created in
17280-408: The surface. The final step in the process of casting usually involves grinding, sanding, or machining the component in order to achieve the desired dimensional accuracies, physical shape, and surface finish. Removing the remaining gate material, called a gate stub, is usually done using a grinder or sander . These processes are used because their material removal rates are slow enough to control
17415-482: The type of foundry, metal to be poured, quantity of parts to be produced, size of the casting, and complexity of the casting. These mold processes include: In a foundry, molten metal is poured into molds . Pouring can be accomplished with gravity, or it may be assisted with a vacuum or pressurized gas. Many modern foundries use robots or automatic pouring machines to pour molten metal. Traditionally, molds were poured by hand using ladles . The solidified metal component
17550-414: The type of metals that are to be melted. Furnaces must also be designed based on the fuel being used to produce the desired temperature. For low temperature melting point alloys, such as zinc or tin, melting furnaces may reach around 500 °C (932 °F). Electricity, propane, or natural gas are usually used to achieve these temperatures. For high melting point alloys such as steel or nickel-based alloys,
17685-531: The value of waste material. Higher income levels from the sale of quality recyclates can return value significant to local governments, households and businesses. Pursuing high-quality recycling can also promote consumer and business confidence in the waste and resource management sector, and may encourage investment in it. There are many actions along the recycling supply chain, each of which can affect recyclate quality. Waste producers who place non-target and non-recyclable wastes in recycling collections can affect
17820-888: The waste producer to carry recyclates to a central location—either an installed or mobile collection station or the reprocessing plant itself. They are the easiest type of collection to establish but suffer from low and unpredictable throughput. For some waste materials such as plastic, recent technical devices called recyclebots enable a form of distributed recycling called DRAM ( distributed recycling additive manufacturing ). Preliminary life-cycle analysis (LCA) indicates that such distributed recycling of HDPE to make filament for 3D printers in rural regions consumes less energy than using virgin resin, or using conventional recycling processes with their associated transportation. Another form of distributed recycling mixes waste plastic with sand to make bricks in Africa . Several studies have looked at
17955-631: Was collected by " dustmen " and downcycled as a base material for brick making. These forms of recycling were driven by the economic advantage of obtaining recycled materials instead of virgin material, and the need for waste removal in ever-more-densely populated areas. In 1813, Benjamin Law developed the process of turning rags into " shoddy " and " mungo " wool in Batley, Yorkshire, which combined recycled fibers with virgin wool . The West Yorkshire shoddy industry in towns such as Batley and Dewsbury lasted from
18090-441: Was immediately employed in glass making. An early politically connected and wealthy Robber Baron figure Sir Robert Mansell bought his way into the fledgling furnace company and wrested control of it, and by 1615 managed to have James I issue a proclamation forbidding the use of wood to produce glass, giving his family's extensive coal holdings a monopoly on both source and means of production for nearly half-a-century. Abraham Darby
18225-432: Was only after explosives, and later early powerful steam shovels produced large chunks of materials, chunks originally reduced by hammering in the mine before being loaded into sacks for a trip to the surface, chunks that were eventually also to lead to rails and mine railways transporting bulk aggregations that post-mine face crushing became widely necessary. The earliest of these were in the foundries, but as coal took hold
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