Misplaced Pages

#887112

108-835: The vintage diesel locomotives, EMD FP7s 1510 and 1512, pulling the classic passenger cars are two of only ten remaining in operation in North America. They were originally built for the Alaska Railroad in 1953 by the Electro-Motive Division of General Motors in LaGrange, Illinois. The engines debuted their eagle-inspired paint livery along these rails on March 8, 1997. Before setting out, numbers 1510 and 1512 were meticulously renovated with modern features added for safety. In 2019, these prized locomotives were imprinted with an updated paint motif and advanced mechanics. The tracks on which

216-595: A carnelian bead identified with the Middle Kingdom pharaoh Senusret I , whose reign is dated to 1971–1926 BC. A stela and a statuette of the Egyptian pharaohs Senusret III and Amenemhet III have also been found. However, it is unclear when they first arrived at Ugarit. In the Amarna letters , messages from Ugarit c.  1350 BC written by Ammittamru I , Niqmaddu II , and his queen have been discovered. From

324-413: A heap leaching or dump leaching . The resulting pregnant leach solution is purified by solvent extraction (SX). It is treated with an organic solvent and an organic chelators. The chelators bind the copper ions (and no other ions, ideally), the resulting complexes dissolve in the organic phase. This organic solvent is evaporated, leaving a residue of the copper complexes. The copper ions are liberated from

432-618: A "dark period" in ancient Egyptian history, spanned about 100 years after the end of the Old Kingdom from about 2181 to 2055 BC. Very little monumental evidence survives from this period, especially from the early part of it. The First Intermediate Period was a dynamic time when the rule of Egypt was roughly divided between two areas: Heracleopolis in Lower Egypt and Thebes in Upper Egypt. These two kingdoms eventually came into conflict, and

540-560: A 3rd-millennium BC culture postulated based on a collection of artefacts confiscated in 2001. In modern scholarship, the chronology of the Bronze Age Levant is divided into: The term Neo-Syria is used to designate the early Iron Age . The old Syrian period was dominated by the Eblaite first kingdom , Nagar and the Mariote second kingdom . The Akkadians conquered large areas of

648-442: A concentrates with 27–29% and 37–40% copper contents from chalcopyrite and chalcocite , respectively. Oxidised copper ores include carbonates such as azurite and malachite , the silicate chrysocolla , and sulfates such as atacamite . In some cases, sulfide ores are allowed to degrade to oxides. Such ores are amenable to hydrometallurgy. Specifically, such oxide ores are usually extracted into aqueous sulfuric acid , usually in

756-515: A few years before selling their copper assets. Reportedly gains were not as high as anticipated. Investments in copper mining concentrated in Chile in the 1980s and 1990s given that copper mining in other countries faced problems like political instability ( Peru ), increased environmental requirements (developed countries) or overall disinterest in foreign investment in a nationalized mining industry ( Zaire , Zambia ). The average grade of copper ores in

864-406: A high grade copper concentrate. The roasting process is generally undertaken in combination with reverberatory furnaces . In the roaster, the copper concentrate is partially oxidised to produce " calcine ". Sulfur dioxide is liberated. The stoichiometry of the reaction is: Roasting generally leaves more sulfur in the calcined product (15% in the case of the roaster at Mount Isa Mines ) than

972-488: A higher profit. This extraction process can be applied to large quantities of low-grade ores, at a lower capital cost with minimal environmental impact. Generally, direct froth flotation is not used to concentrate copper oxide ores, as a result of the largely ionic and hydrophilic structure of the copper oxide mineral surface. Copper oxide ores are typically treated via chelating-reagent flotation and fatty-acid flotation, which use organic reagents to ensure adsorption onto

1080-541: A parallel reaction the iron sulfide is converted to slag: The purity of this product is 98%, it is known as blister because of the broken surface created by the escape of sulfur dioxide gas as blister copper pigs or ingots are cooled. By-products generated in the process are sulfur dioxide and slag . The sulfur dioxide is captured and converted to sulfuric acid and either sold on the open market or used in copper leaching processes. Bronze Age The Bronze Age ( c.  3300  – c.  1200 BC )

1188-402: A permanence not enjoyed by manuscripts. These inscriptions can commonly be subdivided into four parts: a reference to the date and place, the naming of the event commemorated, the list of gifts given to the artisan in exchange for the bronze, and a dedication. The relative points of reference these vessels provide have enabled historians to place most of the vessels within a certain time frame of

SECTION 10

#1732851006888

1296-562: A power vacuum in Mesopotamia. At its beginning, Mitanni's major rival was Egypt under the Thutmosids . However, with the ascent of the Hittite empire, Mitanni and Egypt allied to protect their mutual interests from the threat of Hittite domination. At the height of its power during the 14th century BC, Mitanni had outposts centred on its capital, Washukanni , which archaeologists have located on

1404-400: A series of physical, chemical, and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations , and other factors. The Old Copper Complex in North America has been radiometrically dated to 9500 BP—i.e., about 7480 BCE—making it one of the oldest known examples of copper extraction in the world. The earliest evidence of

1512-424: A significant portion of the sulfur has been eliminated during the roasting stage, and the calcine consists of a mixture of copper and iron oxides and sulfides. The reverberatory furnace acts to allow these species to approach chemical equilibrium at the furnace operating temperature (approximately 1600 °C at the burner end of the furnace and about 1200 °C at the flue end; the matte is about 1100 °C and

1620-515: A sinter plant leaves in the sintered product (about 7% in the case of the Electrolytic Refining and Smelting smelter ). As of 2005, roasting is no longer common in copper concentrate treatment because its combination with reverberatory furnaces is not energy efficient and the SO 2 concentration in the roaster offgas is too dilute for cost-effective capture. Direct smelting is now favored, and uses

1728-472: A small administrative town) appears on a tablet from the reign of Sargon of Akkad in the 23rd century BC. The Amorite dynasty established the city-state of Babylon in the 19th century BC. Over a century later, it briefly took over the other city-states and formed the short-lived First Babylonian Empire during what is also called the Old Babylonian Period . Akkad, Assyria, and Babylonia used

1836-474: Is a minor part of a supergene profile it will not be recovered and will report to the tailings . When rich enough, native copper ore bodies may be treated to recover the contained copper by gravity separation . Often, the nature of the gangue is important, as clay-rich native copper ores prove difficult to liberate. This is because clay minerals interact with flotation reagents used in extraction processes, that are then consumed, which results in minimal recovery of

1944-422: Is a mixture of copper, iron and sulfur that is enriched in copper, which is called matte or copper matte . The term matte grade is normally used to refer to the copper content of the matte. The purpose of the matte smelting stage is to eliminate as much of the unwanted iron, sulfur and gangue minerals (such as silica, magnesia, alumina and limestone) as possible, while minimizing the loss of copper. This

2052-421: Is achieved by reacting iron sulfides with oxygen (in air or oxygen enriched air) to produce iron oxides (mainly as FeO , but with some magnetite (Fe 3 O 4 )) and sulfur dioxide . Copper sulfide and iron oxide can mix, but when sufficient silica is added, a separate slag layer is formed. Adding silica also reduces the melting point (or, more properly, the liquidus temperature) of the slag, meaning that

2160-620: Is an argument to be made that the Bronze Age never properly ended in China, as there is no recognisable transition to an Iron Age. Together with the jade art that precedes it, bronze was seen as a fine material for ritual art when compared with iron or stone. Bronze metallurgy in China originated in what is referred to as the Erlitou period, which some historians argue places it within the Shang. Others believe

2268-608: Is an energy-efficient smelting process that was jointly developed from the 1970s to the 1990s by Mount Isa Mines (a subsidiary of MIM Holdings and now part of Glencore ) and the Government of Australia 's CSIRO . It has relatively low capital and operating costs for a smelting process. ISASMELT technology has been applied to lead, copper, and nickel smelting. As of 2021, 22 plants were in operation in eleven countries, along with three demonstration plants located at Mt Isa. The installed capacity of copper/nickel operating plants in 2020

SECTION 20

#1732851006888

2376-470: Is at Timna Valley , Israel, and has been used since the fourth millennium BC, with surface deposit usage occurring in the fifth and sixth millennium. The Pločnik archaeological site in southeastern Europe ( Serbia ) contains the oldest securely dated evidence of copper making at high temperature, from 5,000 BCE. The find in June 2010 extends for an additional 500 years, dated to 5th millennium BCE, representing

2484-565: Is called the Bactria–Margiana Archaeological Complex . The Kulli culture , similar to that of the Indus Valley Civilisation , was located in southern Balochistan (Gedrosia) c.  2500–2000 BC . The economy was agricultural. Dams were found in several places, providing evidence for a highly developed water management system. Konar Sandal is associated with the hypothesized Jiroft culture ,

2592-637: Is conjectured to have been associated with the sudden arrival of the Sea Peoples , the kingdom disintegrated into several independent "Neo-Hittite" city-states, some of which survived into the 8th century BC. Arzawa , in Western Anatolia, during the second half of the 2nd millennium BC, likely extended along southern Anatolia in a belt from near the Turkish Lakes region to the Aegean coast. Arzawa

2700-465: Is constantly forced through the slurry. The air bubbles attach to the hydrophobic copper sulfide particles, which are conveyed to the surface where the froth is skimmed off. These skimmings are generally subjected to a cleaner-scavenger cell to remove excess silicates and to remove other sulfide minerals that can deleteriously impact the concentrate quality (typically, galena ), and the final concentrate sent for smelting. The rock that has not floated off in

2808-411: Is eliminated from the concentrate). It is essentially a melting process. Consequently, wet-charged reverberatory furnaces have less copper in their matte product than calcine-charged furnaces, and they also have lower copper losses to slag. Gill quotes a copper in slag value of 0.23% for a wet-charged reverberatory furnace vs 0.37% for a calcine-charged furnace. In the case of calcine-charged furnaces,

2916-517: Is further conjectured that the same migrations spread the Uralic group of languages across Europe and Asia, with extant members of the family including Hungarian , Finnish and Estonian . In China, the earliest bronze artefacts have been found in the Majiayao culture site (3100–2700 BC). The term "Bronze Age" has been transferred to the archaeology of China from that of Western Eurasia, and there

3024-578: Is named after the Korean name for undecorated or plain cooking and storage vessels that form a large part of the pottery assemblage over the entire length of the period, but especially between 850 and 550 BC. The Mumun period is known for the origins of intensive agriculture and complex societies in both the Korean Peninsula and the Japanese Archipelago. The Middle Mumun pottery period culture of

3132-511: Is no consensus or universally used convention delimiting the "Bronze Age" in the context of Chinese prehistory . The "Early Bronze Age" in China is sometimes taken to be coterminous with the reign of the Shang dynasty (16th–11th centuries BC), and the Later Bronze Age with the subsequent Zhou dynasty (11th–3rd centuries BC), from the 5th century, called Iron Age China although there

3240-427: Is normally added to help form the slag. The furnace is fired with burners using pulverized coal, fuel oil or natural gas. Reverberatory furnaces can additionally be fed with molten slag from the later converting stage to recover the contained copper and other materials with a high copper content. Because the reverberatory furnace bath is quiescent, very little oxidation of the feed occurs (and thus very little sulfur

3348-721: The Iranian plateau , centred in Anshan . From the mid-2nd millennium BC, Elam was centred in Susa in the Khuzestan lowlands. Its culture played a crucial role in both the Gutian Empire and the Iranian Achaemenid dynasty that succeeded it. The Oxus civilisation was a Bronze Age Central Asian culture dated c.  2300–1700 BC and centred on the upper Amu Darya ( a.k.a. ). In

Verde Canyon Railroad - Misplaced Pages Continue

3456-516: The Kassite period c.  1500  – c.  1155 BC ). The usual tripartite division into an Early, Middle and Late Bronze Age is not used in the context of Mesopotamia. Instead, a division primarily based on art and historical characteristics is more common. The cities of the Ancient Near East housed several tens of thousands of people. Ur , Kish , Isin , Larsa , and Nippur in

3564-568: The Majiayao site in Gansu rather than at Xinjiang . The production of Erlitou represents the earliest large-scale metallurgy industry in the Central Plains of China. The influence of the Saima-Turbino metalworking tradition from the north is supported by a series of recent discoveries in China of many unique perforated spearheads with downward hooks and small loops on the same or opposite side of

3672-683: The Verde River , crossing bridges and trestles , and passes through a 680-foot-long (210 m) curved tunnel . Between milepost 30 and Perkinsville, most of the land along the railroad right-of-way is in the Prescott National Forest or the Coconino National Forest (across the river). The railroad carries about 100,000 passengers per year. In 2005 the Verde Canyon Railroad celebrated its one-millionth passenger, and

3780-469: The refractory bricks lining the furnace. When the removal of the matte or slag is complete, the hole is normally plugged with clay, which is removed when the furnace is ready to be tapped again. Reverberatory furnaces were often used to treat molten converter slag to recover contained copper. This would be poured into the furnaces from ladles carried by cranes. However, the converter slag is high in magnetite and some of this magnetite would precipitate from

3888-561: The southern Levant in cities such as Hazor , Jericho , and Beit She'an . The Hittite Empire was established during the 18th century BC in Hattusa , northern Anatolia . At its height in the 14th century BC, the Hittite Kingdom encompassed central Anatolia, southwestern Syria as far as Ugarit , and upper Mesopotamia . After 1180 BC, amid general turmoil in the Levant , which

3996-422: The 16th to the 13th century BC, Ugarit remained in constant contact with Egypt and Cyprus ( Alashiya ). Mitanni was a loosely organised state in northern Syria and south-east Anatolia, emerging c.  1500–1300 BC . Founded by an Indo-Aryan ruling class that governed a predominantly Hurrian population, Mitanni came to be a regional power after the Hittite destruction of Kassite Babylon created

4104-450: The 1960s. In the 1960s and 1970s large copper mining operations by U.S. companies were nationalized in many of the main copper producing countries. Thus by the 1980s state owned enterpises overtook the dominant role U.S. companies like Anaconda Copper and Kennecott had had until then. In the late 1970s and early 1980s various oil companies like ARCO , Exxon ( Exxon Minerals ) and Standard Oil Company expanded into copper mining for

4212-517: The 21st century is below 0.6% copper, with a proportion of economic ore minerals being less than 2% of the total volume of the ore rock. Thus, all mining operations, the ore must usually be beneficiated (concentrated). The concentrate is typically sold to distant smelters , although some large mines have smelters located nearby. Such colocation of mines and smelters was more typical in the 19th and early 20th centuries, when smaller smelters could be economic. The subsequent processing techniques depend on

4320-430: The 3rd millennium BC. The Bronze Age is characterised by the widespread use of bronze , though the introduction and development of bronze technology were not universally synchronous. Tin bronze technology requires systematic techniques: tin must be mined (mainly as the tin ore cassiterite ) and smelted separately, then added to hot copper to make bronze alloy. The Bronze Age was a time of extensive use of metals and

4428-766: The 6th century BC attests to knowledge of iron smelting, yet bronze continues to occupy the seat of significance in the archaeological and historical record for some time after this. W. C. White argues that iron did not supplant bronze "at any period before the end of the Zhou dynasty (256 BC)" and that bronze vessels make up the majority of metal vessels through the Eastern Han period , or to 221 BC. The Chinese bronze artefacts generally are either utilitarian, like spear points or adze heads, or "ritual bronzes" , which are more elaborate versions in precious materials of everyday vessels, as well as tools and weapons. Examples are

Verde Canyon Railroad - Misplaced Pages Continue

4536-500: The BMAC had close international relations with the Indus Valley , the Iranian plateau , and possibly even indirectly with Mesopotamia. All civilisations were familiar with lost wax casting . According to a 2019 study, the BMAC was not a primary contributor to later South-Asian genetics. The Altai Mountains , in what is now southern Russia and central Mongolia , have been identified as

4644-635: The Bronze Age began in the Protodynastic Period c.  3150 BC . The archaic Early Bronze Age of Egypt , known as the Early Dynastic Period of Egypt , immediately followed the unification of Lower and Upper Egypt, c.  3100 BC . It is generally taken to include the First and Second dynasties, lasting from the Protodynastic Period until c.  2686 BC , or

4752-578: The Early Bronze Age, the culture of the Kopet Dag oases and Altyndepe developed a proto-urban society. This corresponds to level IV at Namazga-Tepe . Altyndepe was a major centre even then. Pottery was wheel-turned. Grapes were grown. The height of this urban development was reached in the Middle Bronze Age c.  2300 BC , corresponding to level V at Namazga-Depe. This Bronze Age culture

4860-520: The Erlitou sites belong to the preceding Xia dynasty . The United States National Gallery of Art defines the Chinese Bronze Age as c.  2000  – c.  771 BC , a period that begins with the Erlitou culture and ends abruptly with the disintegration of Western Zhou rule. There is reason to believe that bronze work developed inside of China apart from outside influence. However,

4968-621: The Levant and were followed by the Amorite kingdoms , c.  2000–1600 BC , which arose in Mari , Yamhad , Qatna , and Assyria . From the 15th century BC onward, the term Amurru is usually applied to the region extending north of Canaan as far as Kadesh on the Orontes River . The earliest-known contact of Ugarit with Egypt (and the first exact dating of Ugaritic civilisation) comes from

5076-700: The Middle Bronze Age and Babylon , Calah , and Assur in the Late Bronze Age similarly had large populations. The Akkadian Empire (2335–2154 BC) became the dominant power in the region. After its fall, the Sumerians enjoyed a renaissance with the Neo-Sumerian Empire . Assyria , along with the Old Assyrian Empire ( c.  1800–1600 BC ), became a regional power under the Amorite king Shamshi-Adad I . The earliest mention of Babylon (then

5184-800: The Middle Kingdom. During the Second Intermediate Period , Ancient Egypt fell into disarray a second time between the end of the Middle Kingdom and the start of the New Kingdom, best known for the Hyksos , whose reign comprised the Fifteenth and Sixteenth dynasties. The Hyksos first appeared in Egypt during the Eleventh Dynasty, began their climb to power in the Thirteenth Dynasty, and emerged from

5292-550: The Osiris funerary cult rose to dominate popular Ancient Egyptian religion . The period comprises two phases: the Eleventh Dynasty, which ruled from Thebes, and the Twelfth and Thirteenth dynasties, centred on el-Lisht . The unified kingdom was previously considered to comprise the Eleventh and Twelfth Dynasties, but historians now consider part of the Thirteenth Dynasty to have belonged to

5400-784: The Second Intermediate Period in control of Avaris and the Nile Delta . By the Fifteenth Dynasty, they ruled lower Egypt. They were expelled at the end of the Seventeenth Dynasty . The New Kingdom of Egypt , also referred to as the Egyptian Empire, existed during the 16th–11th centuries BC. The New Kingdom followed the Second Intermediate Period and was succeeded by the Third Intermediate Period . It

5508-731: The Theban kings conquered the north, reunifying Egypt under a single ruler during the second part of the Eleventh Dynasty . The Bronze Age in Nubia started as early as 2300 BC. Egyptians introduced copper smelting to the Nubian city of Meroë in present-day Sudan c.  2600 BC . A furnace for bronze casting found in Kerma has been dated to 2300–1900 BC. The Middle Kingdom of Egypt spanned between 2055 and 1650 BC. During this period,

SECTION 50

#1732851006888

5616-480: The Verde Canyon Railroad runs were opened in 1912 as part of a north–south branch line linking a copper smelter at Clarkdale and the copper mines at Jerome to Santa Fe Railway tracks passing through Drake . The Santa Fe Railway owned and operated the 38-mile (61 km) branch line from 1912 to 1988. David L. Durbano bought the branch line in 1988. Passenger service between Clarkdale at milepost 38 and Perkinsville at milepost 18, resumed in 1990 under

5724-609: The Western Zhou period, allowing them to trace the evolution of the vessels and the events they record. The Japanese archipelago saw the introduction of bronze during the early Yayoi period ( c.  300 BC ), which saw the introduction of metalworking and agricultural practices brought by settlers arriving from the continent. Bronze and iron smelting spread to the Japanese archipelago through contact with other ancient East Asian civilisations, particularly immigration and trade from

5832-445: The ancient Korean peninsula, and ancient mainland China. Iron was mainly used for agricultural and other tools, whereas ritual and ceremonial artefacts were mainly made of bronze. On the Korean Peninsula, the Bronze Age began c.  1000–800 BC . Initially centred around Liaoning and southern Manchuria, Korean Bronze Age culture exhibits unique typology and styles, especially in ritual objects. The Mumun pottery period

5940-422: The beginning of the Old Kingdom . With the First Dynasty, the capital moved from Abydos to Memphis with a unified Egypt ruled by an Egyptian god-king. Abydos remained the major holy land in the south. The hallmarks of ancient Egyptian civilisation, such as art, architecture and religion, took shape in the Early Dynastic Period. Memphis , in the Early Bronze Age, was the largest city of the time. The Old Kingdom of

6048-460: The cold-hammering of native copper comes from the excavation at Çayönü Tepesi in eastern Anatolia , which dates between 7200 to 6600 BCE. Among the various items considered to be votive or amulets, there was one that looked like a fishhook and one like an awl. Another find, at Shanidar Cave in Mergasur, Iraq, contained copper beads, and dates back to 8,700 BCE. One of the world's oldest known copper mines, as opposed to usage of surface deposits,

6156-412: The concentrate is dispersed in an air or oxygen stream and the smelting reactions are largely completed while the mineral particles are still in flight. The reacted particles then settle in a bath at the bottom of the furnace, where they behave like calcine in a reverberatory furnace. A slag layer forms on top of the matte layer, and they can separately be tapped from the furnace. The ISASMELT process

6264-452: The concentration of copper in the ore bodies decreased, the energy costs of smelting the whole ore also became prohibitive, and it became necessary to concentrate the ores first. Initial concentration techniques included hand-sorting and gravity concentration. These resulted in high losses of copper. Consequently, the development of the froth flotation process was a major step forward in mineral processing. The modern froth flotation process

6372-406: The converter slag (due to its higher melting point), forming an accretion on the hearth of the reverberatory furnace and necessitating shut downs of the furnace to remove the accretion. This accretion formation limits the quantity of converter slag that can be treated in a reverberatory furnace. While reverberatory furnaces have very low copper losses to slag, they are not very energy-efficient and

6480-421: The copper dissolved in slags from mattes containing less than 50% copper is sulfidic copper. Above this figure, oxidic copper begins to dominate. The loss of copper as prills suspended in the slag depends on the size of the prills, the viscosity of the slag and the settling time available. Rosenqvist suggested that about half the copper losses to slag were due to suspended prills. The mass of slag generated in

6588-467: The copper from the pregnant leach solution . To ensure the best recovery of copper, it is important to acknowledge the effect copper dissolution, acid consumption, and gangue mineral composition has on the efficacy of extraction. Supergene sulfide ores rich in native copper are refractory to treatment with sulfuric acid leaching on all practicable time scales, and the dense metal particles do not react with froth flotation media. Typically, if native copper

SECTION 60

#1732851006888

6696-404: The crushed ore is wetted, suspended in a slurry, and mixed with reagents that render the sulfide particles hydrophobic . Typical reagents ("collectors") include potassium ethylxanthate and sodium ethylxanthate , but dithiophosphates and dithiocarbamates are also used. The slurry is introduced to a water-filled aeration tank containing a surfactant such as methylisobutyl carbinol (MIBC). Air

6804-409: The depletion of copper resources. Processes including in situ, dump, and heap leaching are cost-effective methods that are suitable for extracting copper from low-grade ores. Extraction processes for secondary copper sulfides and low-grade ores includes the process of heap bioleaching. Heap bioleaching presents a cost efficient extraction method that requires a less intensive energy input resulting in

6912-425: The development of trade networks. A 2013 report suggests that the earliest tin-alloy bronze was a foil dated to the mid-5th millennium BC from a Vinča culture site in Pločnik , Serbia , although this culture is not conventionally considered part of the Bronze Age; however, the dating of the foil has been disputed. West Asia and the Near East were the first regions to enter the Bronze Age, beginning with

7020-444: The discovery of the Europoid Tarim mummies in Xinjiang has caused some archaeologists such as Johan Gunnar Andersson , Jan Romgard, and An Zhimin to suggest a possible route of transmission from the West eastwards. According to An Zhimin, "It can be imagined that initially, bronze and iron technology took its rise in West Asia, first influenced the Xinjiang region, and then reached the Yellow River valley, providing external impetus for

7128-490: The earlier record of copper smelting from Rudna Glava ( Serbia ). Copper smelting technology gave rise to the Copper Age , aka Chalcolithic Age, and then the Bronze Age . The Bronze Age would not have been possible without the development of smelting technology. Until the latter half of the 20th century, smelting sulfide ores was almost the sole means of producing copper metal from mined ores ( primary copper production). As of 2002, 80% of global primary copper production

7236-471: The fall of the monarchy. The name "Israel" first appears c.  1209 BC , at the end of the Late Bronze Age and the very beginning of the Iron Age, on the Merneptah Stele raised by the Egyptian pharaoh Merneptah . The Arameans were a Northwest Semitic semi-nomadic pastoral people who originated in what is now modern Syria (Biblical Aram ) during the Late Bronze and early Iron Age. Large groups migrated to Mesopotamia, where they intermingled with

7344-415: The first to develop writing . According to archaeological evidence, cultures in Mesopotamia , which used cuneiform script, and Egypt , which used hieroglyphs , developed the earliest practical writing systems. Bronze Age civilisations gained a technological advantage due to bronze's harder and more durable properties than other metals available at the time. While terrestrial iron is naturally abundant,

7452-402: The flotation cell is either discarded as tailings or further processed to extract other metals such as lead (from galena) and zinc (from sphalerite ), should they exist. A variety of measures are taken to improve the efficiency of the froth flotation. Lime is used to raise the pH of the water bath, causing the collector to bond more efficiently to the copper sulfides. The process can produce

7560-444: The following month was named an "Arizona Treasure" by Arizona Governor Janet Napolitano . The John Bell Railroad Museum is part of the depot complex in Clarkdale. Housed in an old boxcar, the museum displays rail artifacts and photographs, many of which came from Bell's personal collection. Copper mine Copper extraction refers to the methods used to obtain copper from its ores . The conversion of copper ores consists of

7668-449: The following smelting technologies: flash smelting , Isasmelt , Noranda, Mitsubishi or El Teniente furnaces. The initial melting of the material to be smelted is usually referred to as the smelting or matte smelting stage. It can be undertaken in a variety of furnaces, including the largely obsolete blast furnaces and reverberatory furnaces , as well as flash furnaces , Isasmelt furnaces, etc. The product of this smelting stage

7776-427: The furnace as separate streams. The slag layer is periodically allowed to flow through a hole in the wall of the furnace above the height of the matte layer. The matte is removed by draining it through a hole into ladles for it to be carried by crane to the converters. This draining process is known as tapping the furnace. The matte taphole is normally a hole through a water-cooled copper block that prevents erosion of

7884-656: The headwaters of the Khabur River . Eventually, Mitanni succumbed to the Hittites and later Assyrian attacks, eventually being reduced to a province of the Middle Assyrian Empire . The Israelites were an ancient Semitic-speaking people of the Ancient Near East who inhabited part of Canaan during the tribal and monarchic periods (15th–6th centuries BC), and lived in the region in smaller numbers after

7992-688: The higher temperature required for smelting, 1,250 °C (2,280 °F), in addition to the greater difficulty of working with it, placed it out of reach of common use until the end of the 2nd millennium BC. Tin's lower melting point of 232 °C (450 °F) and copper's moderate melting point of 1,085 °C (1,985 °F) placed both these metals within the capabilities of Neolithic pottery kilns , which date to 6000 BC and were able to produce temperatures of at least 900 °C (1,650 °F). Copper and tin ores are rare since there were no tin bronzes in West Asia before trading in bronze began in

8100-459: The loss of copper to slag in the smelting stage are: This means that there is a practical limit on how high the matte grade can be if the loss of copper to slag is to be minimized. Therefore, further stages of processing (converting and fire refining) are required. The following subsections briefly describe some of the processes used in matte smelting. Reverberatory furnaces are long furnaces that can treat wet, dry, or roasted concentrate. Most of

8208-463: The low concentrations of sulfur dioxide in their off-gases make its capture uneconomic. Consequently, smelter operators devoted a lot of money in the 1970s and 1980s to developing new, more efficient copper smelting processes. In addition, flash smelting technologies had been developed in earlier years and began to replace reverberatory furnaces. By 2002, 20 of the 30 reverberatory furnaces still operating in 1994 had been shut down. In flash smelting ,

8316-437: The mineral chalcocite; a mineral formed from primary sulfides, like chalcopyrite , that undergo chemical processes such as oxidation or reduction. Typically, secondary sulfide ores are concentrated using froth flotation. Other extraction processes like leaching are effectively used for the extraction of secondary copper sulfides, but as demand for copper rises, extraction processes tailored for low-grade ores are required, due to

8424-426: The mineral surface through the formation of hydrophobic compounds on the mineral surface. Some supergene sulfide deposits can be leached using a bacterial oxidation heap leach process to oxidize the sulfides to sulfuric acid, which also allows for simultaneous leaching with sulfuric acid to produce a copper sulfate solution. For oxide ores, solvent extraction and electrowinning technologies are used to recover

8532-582: The name Verde Canyon Railroad . Milepost 0 of the AZCR is at Drake, where the line meets the BNSF Railway system. The AZCR track to Drake is still used for hauling freight even though the excursion line stops at Perkinsville. Excursions involve a 4-hour, 40-mile (64 km) round trip from Clarkdale to Perkinsville and back. Scenes from How the West Was Won were filmed at Perkinsville in 1960s. The route follows

8640-597: The native Akkadian (Assyrian and Babylonian) population. The Aramaeans never had a unified empire; they were divided into independent kingdoms all across the Near East. After the Bronze Age collapse, their political influence was confined to Syro-Hittite states, which were entirely absorbed into the Neo-Assyrian Empire by the 8th century BC. The Mesopotamian Bronze Age began c.  3500 BC and ended with

8748-409: The nature of the ore. In the usual case when it is primarily sulfide copper minerals (such as chalcopyrite , FeCuS 2 ), the ore is treated by comminution , where the rock is crushed to produce small particles (<100 μm) consisting of individual mineral phases. These particles are then ready to be separated to remove gangue (silicate rocks residues) using froth flotation. In froth flotation,

8856-408: The numerous large sacrificial tripods known as dings ; there are many other distinct shapes. Surviving identified Chinese ritual bronzes tend to be highly decorated, often with the taotie motif, which involves stylised animal faces. These appear in three main motif types: those of demons, symbolic animals, and abstract symbols. Many large bronzes also bear cast inscriptions that are the bulk of

8964-688: The origins of agriculture. Foothill regions and glacial melt streams supported Bronze Age agro-pastoralists who developed complex east–west trade routes between Central Asia and China that introduced wheat and barley to China and millet to Central Asia. The Bactria–Margiana Archaeological Complex (BMAC), also known as the Oxus civilisation, was a Bronze Age civilisation in Central Asia, dated c.  2400  – c.  1600 BC , located in present-day northern Afghanistan , eastern Turkmenistan , southern Uzbekistan and western Tajikistan , centred on

9072-403: The oxygen potential of the slag increases. The oxygen potential generally increases as the copper content of the matte is increased. Thus, the loss of copper as oxide increases as the copper content of the matte increases. On the other hand, the solubility of sulfidic copper in slag decreases as the copper content of the matte increases beyond about 40%. Nagamori calculated that more than half

9180-578: The point of origin of a cultural enigma termed the Seima-Turbino Phenomenon . It is conjectured that changes in climate in this region c.  2000 BC }}, and the ensuing ecological, economic, and political changes, triggered a rapid and massive migration westward into northeast Europe, eastward into China, and southward into Vietnam and Thailand across a frontier of some 4,000 mi (6,000 km). This migration took place in just five to six generations and led to peoples from Finland in

9288-521: The region laid the foundations for astronomy , mathematics, and astrology . The following dates are approximate. The Bronze Age in the Near East can be divided into Early, Middle and Late periods. The dates and phases below apply solely to the Near East, not universally. However, some archaeologists propose a "high chronology", which extends periods such as the Intermediate Bronze Age by 300 to 500–600 years, based on material analysis of

9396-466: The regional Bronze Age is the name given to the period in the 3rd millennium BC when Egyptian civilisation attained its first continuous peak of complexity and achievement—the first of three "Kingdom" periods which marked the high points of civilisation in the lower Nile Valley (the others being the Middle Kingdom and New Kingdom ). The First Intermediate Period of Egypt , often described as

9504-517: The residue with sulfuric acid. The barred (denuded) sulfuric acid recycled back on to the heaps. The organic ligands are recovered and recycled as well. Alternatively, the copper can be precipitated out of the pregnant solution by contacting it with scrap iron; a process called cementation . Cement copper is normally less pure than SX-EW copper. Secondary sulfides—those formed by supergene secondary enrichment—are resistant ( refractory ) to sulfuric leaching. Secondary copper sulfides are dominated by

9612-428: The reverberatory furnaces used in the latter years treated roasted concentrate because putting dry feed materials into the reverberatory furnace is more energy efficient, and because the elimination of some of the sulfur in the roaster results in higher matte grades. The reverberatory furnace feed is added to the furnace through feed holes along the sides of the furnace, and the solid charge is melted. Additional silica

9720-648: The rise of the Mesopotamian civilisation of Sumer in the mid-4th millennium BC. Cultures in the ancient Near East practised intensive year-round agriculture; developed writing systems ; invented the potter's wheel , created centralised governments (usually in the form of hereditary monarchies ), formulated written law codes, developed city-states , nation-states and empires; embarked on advanced architectural projects; and introduced social stratification , economic and civil administration, slavery , and practised organised warfare, medicine, and religion. Societies in

9828-530: The rise of the Shang and Zhou civilizations." According to Jan Romgard, "bronze and iron tools seem to have traveled from west to east as well as the use of wheeled wagons and the domestication of the horse." There are also possible links to Seima-Turbino culture , "a transcultural complex across northern Eurasia", the Eurasian steppe, and the Urals. However, the oldest bronze objects found in China so far were discovered at

9936-403: The slag is about 1195 °C ). In this equilibration process, oxygen associated with copper compounds exchanges with sulfur associated with iron compounds, increasing the iron oxide content of the furnace, and the iron oxides interact with silica and other oxide materials to form the slag. The main equilibration reaction is: The slag and the matte form distinct layers that can be removed from

10044-453: The smelting process can be operated at a lower temperature. The slag forming reaction is: Slag is less dense than matte, so it forms a layer that floats on top of the matte. Copper can be lost from the matte in three ways: as cuprous oxide (Cu 2 O) dissolved in the slag, as sulfide copper dissolved in the slag or as tiny droplets (or prills ) of matte suspended in the slag. The amount of copper lost as oxide copper increases as

10152-401: The smelting stage depends on the iron content of the material fed into the smelting furnace and the target matte grade. The greater the iron content of the feed, the more iron that will need to be rejected to the slag for a given matte grade. Similarly, increasing the target matte grade requires the rejection of more iron and an increase in the slag volume. Thus, the two factors that most affect

10260-682: The socket, which could be associated with the Seima-Turbino visual vocabulary of southern Siberia. The metallurgical centres of northwestern China, especially the Qijia culture in Gansu and Longshan culture in Shaanxi , played an intermediary role in this process. Iron use in China dates as early as the Zhou dynasty ( c.  1046  – 256 BC), but remained minimal. Chinese literature authored during

10368-509: The southern Korean Peninsula gradually adopted bronze production ( c.  700–600 BC ) after a period when Liaoning-style bronze daggers and other bronze artefacts were exchanged as far as the interior part of the Southern Peninsula ( c.  900–700 BC ). The bronze daggers lent prestige and authority to the personages who wielded and were buried with them in high-status megalithic burials at south-coastal centres such as

10476-413: The surviving body of early Chinese writing and have helped historians and archaeologists piece together the history of China, especially during the Zhou dynasty. The bronzes of the Western Zhou document large portions of history not found in the extant texts that were often composed by persons of varying rank and possibly even social class. Further, the medium of cast bronze lends the record they preserve

10584-761: The two known as the Chalcolithic . The final decades of the Bronze Age in the Mediterranean basin are often characterised as a period of widespread societal collapse known as the Late Bronze Age collapse ( c.  1200  – c.  1150 BC ), although its severity and scope is debated among scholars. An ancient civilisation is deemed to be part of the Bronze Age if it either produced bronze by smelting its own copper and alloying it with tin , arsenic , or other metals, or traded other items for bronze from producing areas elsewhere. Bronze Age cultures were

10692-557: The upper Amu Darya (Oxus River). Its sites were discovered and named by the Soviet archaeologist Viktor Sarianidi (1976). Bactria was the Greek name for the area of Bactra (modern Balkh ), in what is now northern Afghanistan, and Margiana was the Greek name for the Persian satrapy of Marguš , the capital of which was Merv in present-day Turkmenistan. A wealth of information indicates that

10800-403: The west to Thailand in the east employing the same metalworking technology and, in some areas, horse breeding and riding. However, recent genetic testings of sites in south Siberia and Kazakhstan ( Andronovo horizon) would rather support spreading of the bronze technology via Indo-European migrations eastwards, as this technology had been well known for quite a while in western regions. It

10908-525: The written East Semitic Akkadian language for official use and as a spoken language. By that time, the Sumerian language was no longer spoken, but was still in religious use in Assyria and Babylonia, and would remain so until the 1st century AD. The Akkadian and Sumerian traditions played a major role in later Assyrian and Babylonian culture. Despite this, Babylonia, unlike the more militarily powerful Assyria,

11016-419: Was 9.76 million tonnes per year of feed materials and 750 thousand tonnes per year across lead operating plants. The matte, which is produced in the smelter, contains 30–70% copper (depending on the process used and the operating philosophy of the smelter), primarily as copper sulfide, as well as iron sulfide. The sulfur is removed at a high temperature as sulfur dioxide by blowing air through molten matte: In

11124-502: Was Egypt's most prosperous time and marked the peak of Egypt's power. The later New Kingdom, comprising the Nineteenth and Twentieth dynasties (1292–1069 BC), is also known as the Ramesside period , after the eleven pharaohs who took the name of Ramesses. Elam was a pre-Iranian ancient civilisation located east of Mesopotamia. In the Middle Bronze Age, Elam consisted of kingdoms on

11232-560: Was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of the three-age system , following the Stone Age and preceding the Iron Age . Conceived as a global era, the Bronze Age follows the Neolithic , with a transition period between

11340-461: Was founded by non-native Amorites and often ruled by other non-indigenous peoples such as the Kassites , Aramaeans and Chaldeans , as well as by its Assyrian neighbours. For many decades, scholars made superficial reference to Central Asia as the "pastoral realm" or alternatively, the "nomadic world", in what researchers call the "Central Asian void": a 5,000-year span that was neglected in studies of

11448-425: Was from copper–iron–sulfur minerals, and the vast majority of these were treated by smelting. Copper was initially recovered from sulfide ores by directly smelting the ore in a furnace. The smelters were initially located near the mines to minimize the cost of transport. This avoided the prohibitive costs of transporting the waste minerals and the sulfur and iron present in the copper-containing minerals. However, as

11556-581: Was independently invented in the early 1900s in Australia by C.V Potter and around the same time by G. D. Delprat . It made the development of the giant Bingham Canyon mine in Utah possible. In the twentieth century, most ores were concentrated before smelting. Smelting was initially undertaken using sinter plants and blast furnaces , or with roasters and reverberatory furnaces . Roasting and reverberatory furnace smelting dominated primary copper production until

11664-523: Was the western neighbour of the Middle and New Hittite Kingdoms , at times a rival and, at other times, a vassal. The Assuwa league was a confederation of states in western Anatolia defeated by the Hittites under the earlier Tudhaliya I c.  1400 BC . Arzawa has been associated with the more obscure Assuwa generally located to its north. It probably bordered it, and may have been an alternative term for it during some periods. In Ancient Egypt ,

#887112