Copper ores are used for copper (copper content - 1 ... 6%), as well as copper waste and its alloys.

Copper in nature is in the form of sulfur compounds ( CUS., Cu. 2 S.), oxides ( Cuo., Cu. 2 O.), bicarbonates ( Cu.(Oh.) 2 ), carbon dioxide ( Cuco. 3 ) As part of sulphide ores and native metallic copper.

The most common ores are copper cchedan and copper glitter containing 1 ... 2% copper.

90% of primary copper is obtained by a pyrometallurgical method, 10% - hydrometallurgical.

Hydrometallurgical method – preparation of copper by leaching it with a weak solution of sulfuric acid and the subsequent release of metal copper from the solution. The method is used in the processing of poor ores, it does not allow to extract precious metals in terms of copper.

Obtaining media pyrometallurgical It consists of enrichment, firing, smelting for matte, purge in a converter, refining.

Enrichment Copper ores are performed by flotation and oxidative firing.

Flotation method Based on the use of different wettability of copper-containing particles and empty breed. The entity of flotation consists in selective adhesion of some mineral particles suspended in an aqueous medium, to the surface of air bubbles, with which these mineral particles rise to the surface. The method allows to obtain a copper powdered concentrate containing 10 ... 35% copper.

Copper ores and concentrates containing large quantities of sulfur exposed oxidative firing. In the process of heating the concentrate or ore to 700 ... 800 0 C in the presence of air oxygen, the sulfides are oxidized and the content of sulfur is almost doubled against the source. They only burn the poor (with copper content of 8 ... 25%) concentrates, and rich (25 ... 35% copper) weave without firing.

After the roasting of the ore and copper concentrate are exposed floating on Stein, which is an alloy containing copper and iron sulphides ( Cu. 2 S., Fes.). Stein contains 20 ... 50% copper, 20 ... 40% iron, 22 ... 25% sulfur, about 8% oxygen and nickel impurities, zinc, lead, gold, silver. Depending on the chemical composition of the ore and its physical condition, the mattes are obtained either in mine furnaces, if the raw material serves a lumpy copper ore, containing a lot of sulfur, or in reflective furnaces, if the source product is a powdered flotation concentrate. Most often, the smelting is made in fiery reflective furnaces. Temperature in the smelting zone - 1450 0 C.

The resulting copper matte, for the oxidation of sulfides and iron, is purged with compressed air in horizontal converters with side blast. The formed oxides are translated into the slag, and sulfur - in SO 2. Heat in the converter is allocated due to the flow of chemical reactions without fuel supply. The temperature in the converter is 1200 ... 1300 ºC. Thus, in the converter get black coppercontaining 98.4 ... 99.4% copper, 0.01 ... 0.04% iron, 0.02 ... 0.1% sulfur and not a large number of Nickel, tin, antimony, silver, gold. This copper is poured into the bucket and poured into the steel mold or on the casting machine.

Black copper refine to remove harmful impurities, spend firing, and then electrolytic refining.

Essence fire refining The draft copper lies in the oxidation of impurities with greater affinity for oxygen than copper, removing them with gases and translating into the slag. After firing refining, copper purity is obtained 99 ... 99.5%. It is spilled in the mold and receives pigs for further smelting of alloys (bronze and brass) or ingots for electrolytic refining.

Electrolytic refiningconducted to obtain pure copper impurities (99.95% Cu.).

Electrolysis is carried out in baths, where the anode is made from copper firing refining, and the cathode is made of thin sheets of clean copper. An aqueous solution is an electrolyte Cuso 4. (10 ... 16%) and H 2 SO 4 (10…16 %).

When the constant current is passed, the anode is dissolved, copper goes into the solution, and copper ions are discharged at cathodes, precipitated on them with a layer of pure copper.

Impurities are deposited on the bottom of the bath in the form of a sludge, which goes on the processing for the extraction of metals: silver, antimony, selenium, tellurium, gold, etc.

Cathodes are discharged after 5 ... 12 days, when their mass reach 60 ... 90 kg. They are thoroughly washed, and then interpret in electric hollows.

Copper clean is divided into brands: M0 (99.95% Cu.), M1 (99.9%), M2 (99.7%), M3 (99.5%), M4 (99%).

Today there will be another cognitive production report in which we learn how copper produces. IN technical subtleties The process is completely optional, you can simply see the spectacular technological photos.

To do this, you need to go to Karabash - the most dirty city of the planet or one of them. The name Karabash in Tatar means "Black Head". It is a city in the Chelyabinsk region with a population of only 15,000 people, which arose in 1822 after the opening of gold-axes in the place of the ancient Tatar settlement.

"Karabashmed" is one of the oldest copper-smelting enterprises of the Southern Urals, which are in the above city of Karabash. The main activity is the production of draft copper. This is a city-forming enterprise of the city of Karabash Chelyabinsk region.

This is another enterprise - the "Kyshtym Medeelectric Policy Plant" is located in the city of Kyshta Chelyabinsk region. The main activity is the production of cathode copper and precious metals from draft copper and secondary copper-containing raw materials:

"Karabashmed". Here are old furnaces:

Copper concentrate loading:

The main building of the processing factory with a bunch of mechanisms:

The commissioning of a new copper smelter allowed to increase the productivity of the enterprise to 90 thousand tons of draft copper per year. So beautifully looks the fill of the matte (intermediate product in non-ferrous metallurgy) into the converter:

The contents of the smelting furnace samother runs to the sump. There are gases out of it. The impurities float up in the form of a slag, and more severe roughing copper lowers at the bottom.

The melters periodically, as accumulated, drained the slag in the huge buckets from the stove.

Alloy temperature - 1150 degrees Celsius:

Issue a slag from the mixer furnace:

Pouring slag into the bowl:

Drain of slag in the pit:

Very spectacular process!

View from:

Due to the fact that during the years of Soviet power, the equipment of the enterprise was practically not upgraded, by the end of the 20th century the ecological situation in Karabash was extremely aggravated. On June 25, 1996, the city of Karabash and adjacent territories were characterized as an ecological disaster zone.

From the beginning of the XXI century, a gradual modernization of production is carried out at the plant and the transition to more technologies to ecology. In 2009, the Ministry of Natural Resources and Ecology of the Russian Federation excluded Karabash from the list of cities with the highest level of atmospheric pollution, but the situation is heavy there, however.

And this is a Kyshtym Medeelectric Plant. The company deals with the refining of draft copper, processing copper scrap and waste containing precious metals:

And also produces copper and precious metals:

This is what the process is called firing refining. In general, refining is cleaning something from extraneous impurities (probably all familiar with refined sugar):

The process of fire refining is carried out in a copper smelter, with a capacity of 112 thousand tons of anodes per year.

Sampling with a melting furnace "Maerz", a capacity of 380 tons, to determine the chemical composition and degree of metal availability:

Anodusive car:

Metal casting process in copper mold:

There is also a reflective oven an-1 with a capacity of 140 tons, with a capacity of 42 thousand tons of anodes per year:

The production process is based on the first non-coordinated electrolytic refining technology in Russia. Due to it, it was possible to achieve a very high purity of cathode copper (the average copper content in cathodes is 99.997%).

Uploaded matrices with cathode copper:

Then there is a washing of anodic residues from electrolyte and sludge and laying in the foot. After the packaging of steel tape, the cathode packs are transmitted to shipment:

From draft copper and secondary copper-containing raw materials, the company produces precious metals. For example, in this form initially comes "Gold":

Gold in granules:

Silver in granules:

The process of melting the gold in a crucible electric furnace for the subsequent spill of the metal into dimensional and non-night gold bars:

So the gold bars are obtained:

The process of production of copper wire. It is obtained by continuous casting and rolling:

,

The concept of "technology" when it comes to early stages Wire production, it matters significantly different from the currently accepted. However, as noted in this work, starting with primitive levels of technology, production continued to develop in order to satisfy the most pressing needs, and this trend, no doubt, will determine future achievements in the upcoming centuries.

The discovery of copper in its natural (native) form was one of the many signs of testifying to the exit of humanity from the era of the Stone Age. Since this metal is very soft, it was easy to produce primitive objects various destination With the help of a hammer, such as knives, swords and other weapons. Soon the methods of manufacturing wire made of copper and gold were developed. Although copper was mined in mineshes and was processed by countless ways throughout the Millennium, the most significant improvements in the manufacture of wire manufacturing include only the second half of the XX century. Since the fact that today is used in practice is closely related to the preceding developments, this article is devoted to this relationship, both in terms of history and in terms of the prospects for metalworking. Currently, the brutal part of the wire is widely made from the bar (rod) obtained by the continuous casting method. In this regard, we briefly consider the history of the development of the process of production of copper wire.

Fig. one. Chronology of the beginning of the use of various metals

History of using media

Humanity is likely to start using copper for about 9,000 years BC, when the Egyptians opened copper in its natural native form on Cyprus Island (Cyprus). Initially, this metal was given the name "AES Cyprium", which was subsequently reduced to "Cuprum" (CU - copper). Subsequently appeared english word "Copper" (copper) and the Cu chemical symbol. In alchemy, a symbol, which was also a symbol of a woman, since Venus, the Goddess of Love, was used, was used to be born in Cyprus. The chronology of the first use of copper and other metals widely used in the industry is presented in Fig. 1. As it was possible to expect, several first discovered metals were found in a natural (native) form. Some of the previously known written descriptions of the production of copper are included in the Biblical Old Testament. They belong to about 1400 BC. Four relevant chapters indicating the number of poems related to such metallurgical comments are listed in Table 1.

Table 1. Mention of copper and mining of metals in the Bible

Obviously, in those days, methods of cleaning metals were also well known. Extremely little technical information was documented before publishing in Latin in 1556. "De Re Metallica", written by Georgius Agrikola from Saxony, in which the process of processing copper ore was described in detail. The processes and methods of processing shown in this book began to spread widely. During this period of time in Germany, we began to use ore welning to remove sulfur. In 1869 the most large manufacturer Copper in the world was the Michigan company Calumet and Hecla with an annual production of about 6,200 tons. The first mine in the United States, where the annual production of copper exceeded 50,000 tons, was anaconda (Anaconda). The twentieth century was characterized by the development and large-scale low-grade copper ore

Wire production in antiquity

For the manufacture of wires in the early stages of jewelry development, copper of natural origin and such precious metals as gold and silver were used. The study of the samples of the wire found during archaeological excavations showed that these metals were not treated with conventional methods of drawing, that is, pro-injection through the tapered holes in the filler. The golden necklace belonging to the Egyptian Pharaoh, right in about 2750 BC, was manufactured using the forging technique, that is, by cutting metal sheets on thin strips and the subsequent giving them a round shape with a hammer. Since this technique was extremely primitive, the wire diameter changed along a large limits along its entire length. Forging, no doubt, was used for many centuries. This confirmation is given in the "outcome" (the second book "Old Testament", chapter 39, verse 3): "... And they broke gold into thin plates and cut them on strips to continue to work." Strip twist was another way that the Egyptians used in antiquity for the manufacture of fine wire for jewelry. Metal sheets made of copper or gold cut into thin stripes or tapes. As shown in Fig. 2, these strips or from the very beginning turned into a tube, or twisted along the axis of the ribbon.

Fig. 2.. Formation of wire from thin ribbons: a) folding; b) twisting

In both of these twist methods, the wire was then generated from the ribbon - cold flat rolling or stretching through a rough die. Screening technique was used to approximately 1000 of our era. The third predecessor of modern drawing techniques also began with thin ribbons. They directly stretched through the filters that were manufactured or made of natural stones in which holes were made, or from soft metals - such as copper or iron. These ribbons turned into a tube after one or two broke through the die. From these tubes, then the round wire was formed stretching for one or two passages through the hole of the desired diameter. Then the round wire was formed from the tubes, on which both edges of the ribbon form seam. Sometimes the wire made of precious metals was produced through holes made in the plates of the same metals. Since the wire and filters were made of the same metals, the filters made it possible to produce a small number of tenants, as they were extremely quickly wearing. Then they were melted or recycling another species. Unfortunately, the ancient metal filters were not restored and, no doubt, were recycled. In the ruins of Pompeii after its destruction (in 79 of our era), bronze wire was discovered. However, thorough studies of this material have shown that it was made probably about 600 years earlier. It is difficult to answer the question of how the bronze wire was made - forging or drawing? In order to make an alloy with tin in those times, bemes were used to bring the flame temperature to 1090 ° C. In the references to the wire made in China and India, it is assumed that its production refers to the period of time between 2200 and 2000 to our era.

Fig. 3.. Still installation using the energy of moving water, which was used in Europe in the Middle Ages

Wire production in Middle Ages

In the middle ages for the manufacture of wire for the first time, they began to use a thicker board, in which a series of holes were made with a gradually decreasing diameter so that while stretching the wire through them to gradually reduce its diameter to the desired value. The first information about such a type of tool was obtained as a result of archaeological excavations. This information refers to the period of 700-900 of our era. Honor of the invention of this technique is attributed to the Norwegian Vikings. It is believed that during the VI and X centuries, Venetians and other Italians knew about this method pulling the wire through the holes in a thickerboard.

The honor of the first written description of modern wire fellation techniques is attributed to the German monk named theophylus. Around the 1000 and 1100 years of our era, he wrote a manuscript in Latin, where he gave a description of a thickerboard with a conientive convergent hole, similar to the wires universally used in the modern production of wire. Its description is also similar to the description of the drawing boards found in one of the graves of Vikings. The loophile board was made of bronze with iron inserts with holes for stretching the wire. After theophylus, many written descriptions of the process of manufacturing the wire appeared. In the Middle Ages, the manufacture of wire was often made with dragging using a swing ("Swing Drawing"). By the XIII century of artisans began to call "Schockenzeiher", or kopper wipers. The loophile board with the die was inserted into a stump or a piece of wood. The walker was sitting on a swing, when driving ahead, he was captured by tongs or pliers of a wire near the hole in the drawing board. During the movement of the swing back, the walker stretched the wire through this hole. The process continued until the entire wire was extended through a thicker board. Good result This process was considered to stretch through a rather fetal board of one feet (30.48 cm) wire for one pass. A thin wire was made by a consistent broach through a series of holes that decrease in the diameter: until it was possible to watered it to the coil. This type of wire manufacturing process was used in Germany until the middle of the XVII century. The first substantial technical breakthrough in the width of the wire took place in Germany around 1390, when the energy of moving water was used to perform a swing method of drawing. Pliers (clamp) were driven by a collar (eccentric) on the axis of the impeller. At this time, simple devices were used with rotating water with an impeller, similar to those shown in Fig. 3.

Fig. four. The devices that were used in the XVII century. for manual wire manufacture

This experience was so successful that many water mills in the period of time around 1390 were turned into a wire dragging attitudes. To facilitate manual labor and increased productivity, a variety of aids were adapted - receivers - remoters, drums, coils, etc. Some devices that were used at the end of the XVII century are depicted in Fig. 4. Although it can be assumed that a lubricating agent was used in the manufacture of wire, nothing was known about this up to about 1650, when a message appeared on the use of lubricant from the town near Düsseldorf (Germany). It was found that human urine reduces friction when the wire dragging is so effectively that its use makes it possible to easily produce solid steel wire. It was found that nestless beer is also a good lubricant that reduces friction. Modern analytical means like chromotography are currently used to analyze the metals found during archaeological excavations, to clarify whether a organic (organic matter) was used as lubricating means with wire rolling.

Primary stages of modern wire manufacture

Ferry mechanisms have been introduced into practice slowly and gradually. Accordingly, the manual, and the driven by the energy of the moving water of the device was widely used in the XIX century. In the US, the wire production began only after the American revolution, when it turned out to be impossible to receive a wire from England. By 1834, only three enterprises with an annual production of 15 tons worked in the United States. In the XIX century, the need for wire has increased significantly. After the invention in 1820, the telegraph took a large number of copper wires to transmit signals over the telegraph lines. The invention of the phone in 1876 was another cause of the jerk in the development of the production of wires. In the early telegraph and telephone lines, iron wires were used. Then copper displaced the iron, since it provided a significant increase in electrical conductivity, but only wires made of copper, made by drawing with a slap, could be suspended between the columns without saving or breaks. At this time, completely annealed copper had insufficient tensile strength for use in this way. The subsequent development of wires in the form of a twisted pair not only provided a reduction in interference and losses in the line, but also led to the doubling of the required amount of copper. About the manufacture of drawing boards before the beginning of the XIX century little is known. The brutal part of these devices was made of iron casting. In fact, iron fingerboards, similar to those shown in Fig. 5, also used at the beginning of the 20th century. Holes in them had the same shape and sizes as in modern finishing filters. In the US, approximately in 1870, began to apply filters with diamonds on an industrial scale, and in 1928 - and carbide. John Ribebring became a national celebrity in the United States thanks to the numerous patents received by their inventions, the development of steel ropes and the construction of many suspended bridges, including Brooklynsky. He was associated with the company in Dollar Bay, producing wires and copper cables. In fig. 6 shows a photo taken at this factory at the beginning of the 20th century. In those days, much less attention was paid to the good quality of the surface than in the modern production of wire.

Fig. five. The iron throatful board applied in the first half of the twentieth century. (at the bottom of the drawing - silicone prints of the drawing hole, the profile of the hole is similar to those used in modern filters)

Continuous manufacture of copper rods: History

Until the end of the 20th century, cast blanks for the manufacture of wire were the main form of purified copper castings, which were produced from cathodes obtained on cleansing installations. Electrolytic technically clean copper (ETP) was the main metal used for the manufacture of these cast blanks. The usual installation for the casting process contained a horizontal rotary table or a circle with numerous open casting trays located on the tangent of the circle. Copper casting was carried out without stopping the circle. The preparation of a flat surface of the casting was provided by adjusting the oxygen content, which, in turn, affected the casting density due to the interaction of the gas with the metal. The castings obtained in this way, intended for subsequent rolling and pulling the wire, had a weight of about 100 kg, their ends had a conical or pointed form. Sometimes (if necessary), the support surface was purified from the inclusions of copper oxides. The billets were subjected to hot rolling in the air atmosphere to complete the process of manufacturing the rod. After routing the rod in the bath with sulfuric acid, the ends of the rebounds were combined with the help of contact welding to obtain large length of the rod. The main problems of ensuring the required quality of the rod, inherent in this technological process, include: numerous damage to welding places, multiple pollution by steel particles during hot rolling, small rebound length, macrolics along the entire length of the rebound. Licvation (from lat. Liquatio is a thinning, melting) in metallurgy - segregation, heterogeneity of the chemical composition of the alloy arising from its crystallization. In addition, there is a different degree of copper annealing from the beginning to the end of the rebellion due to the difference in temperatures during hot rolling. The significance of these problems has decreased significantly after the invention of the continuous casting process. Brief chronology of the history of continuous casting and the main events associated with the manufacture of copper rods are presented in Table 2.

Table 2. Historical chronology of industrial continuous casting of copper

A type	Authorship	Year
Main technique
Belt-drive	Lyaman	1882
	Daniels.	1886
	Property	1948
	Ridgemonti	1953
Two-rise installations	Hayseleet	1948
	Hunter Douglas	1951
Oscillating process of smelting	Junghans	1933
	Tissmann	1950
Production of copper blanks
First American Band-Drive Installation	W.E./s.W together with Properzi Caster	1963
First installation of vertical spill	Outokumpu.	1969
First oblique system	G.E.	1970
The first two-year system	Controid	1974
ASTM restrictions on impurities	ASTM.	1983

At the end of the XIX century, numerous attempts to produce colored and ferrous metals using continuous casting method. The biggest part of these attempts ended in failure due to excessive friction of the sliding between the initial hardened surface of the ingot and the surface of the shape, which led to the rupture and leakage of the molten metal on this surface. The relative movement of these two components was eliminated in 1882. The process of continuous smelting was developed using a belt, which was located in the groove made in the side surface of the rotating circle. In 1948, the first industrial process was developed by a properi for lead and zinc, and now it is known as the process "Circle - Drive" ("Wheel and Belt"). One of the modifications of this process was successfully implemented in 1963 at the subsidiary of Western Electric. Over the next few decades, technical additions to this process have been developed for the production of copper. These include: Two-rise Foundry CONTROID Machine, Southwire system with five rotating casting circles (SCR), ESSEX design with three cast circles, in which the molten metal siphon tube is used, and the two castings of the Upcast type of Outokumpu and Rautomead for the production of castings non-oxygen. Almost all the workpieces for the manufacture of copper ETP are manufactured during a continuous process, including the following steps: loading, smelting, casting, hot rolling, removal of the outer layer, etching for removing oxygen surface scale, induction control of the finished rod, tension and listening to the riot. Due to the low casting speed of oxygen-free copper, in which unidirectional solidification occurs, hot rolling cannot be carried out during the overall continuous process.

Principles of metallurgy

Hardening

The basis of industrial production of billets from pure electrolytic copper ETR is the principles of chemical reactions "Gas - Metal" in molten copper. When copper moves from liquid state In solid, shrinkage occurs 4.1%. If this fact is to ignore, very likely education in the ingot of large voids and macropores. To prevent this shrinkage in the metal, oxygen is introduced, which reacts with hydrogen and gray. At the same time, pairs and sulfur dioxide are formed in a gaseous form. The source of both hydrogen and sulfur can be a cathode in which they can fall from electrolyte or from gases formed in the mountain. Couples and sulfur dioxide remain in the ingot, forming internal voids there. Consequently, the density of the ingot after casting is less than the density of the wrought copper. If empties have small sizes and are uniformly distributed, they can be eliminated about two passages through the rolled installation.

Foreign inclusions

Until the middle of the 20th century, many results of studies of the effect of residual impurities (residual pollution) were published on the quality of high-purity copper. Strying inclusions can have a negative impact on copper, reducing the electrical conductivity and the magnitude of the spiral elongation (SEN) from the annealed wire, increasing necessary time and an annealing temperature, reducing the elastic spring ability and the ability to take the desired shape. Some of these elements may also cause cracks and increase fragility. In general, SE, TE, PB and S are the most harmful elements in the production of high-purity copper. Table 3 provides information about the results of the effect of each of the 11 most common elements on the characteristics of pure copper, as an annealing temperature, the coefficient of spiral lengthening and electrical resistance, in the case when each of these elements is added to copper separately.

Table 3.. Influence of impurities

Element	Raising annealing temperature, ° F / ppm	Reducing spiral stretching, mm / ppm	Increased electrical resistance, ICM-cm / ppm
Sulfur	15	10	0,0016
Selenium	15	>50	0,0097
Tellurium	10	20	0,0034
Lead	6	5	0,0009
Bismuth	15	>30	-
Antimony	3	3	0,00029
Arsenic	3	4	0,00056
Tin	5	-	0,00016
Iron	1	-	0,0012
Nickel	1	-	0,00014
Silver	1	2	0,0002

It should be noted that if the predicted properties of industrial copper ETR are based on chemical analysis, manifestation individual elements It does not always coincide with the results of measurements of the characteristics of the finished wire. The cause of these deviations are two factors. First, some impurities can enter each other into a chemical reaction, such as lead and sulfur, forming insoluble intermetallic connections. Secondly, more importantly, the interaction of many solid-state oxygen impurities leads to the formation of insoluble metal oxides. The maximum effect on the behavior and properties of copper impurities is when they are in copper in a state of solid solution. A often useful alternative method for predicting copper behavior is the use of regression equations in relation to chemical analysis. One of these equations is as follows:

RF \u003d 34.7 + 0.25PB + 2,73BI + 2,18SB + 4.62TE + 0.88NI + 028FE,

where the content of the impurities is given in PPM, RF - the hardness f by rokuell (determined by indentation of the conical tip) for the initial cast workpiece. For testing, the billet is first subjected to cold rolling to a diameter of 30% of the initial value, followed by annealing for 15 minutes in a constant temperature of 275 ° C before starting the hardness measurements. If the number of hardness F is less than 60, then copper is classified as weakly annealed.

Oxygen

As noted in the previous section, the administration of oxygen into the melt is associated with the need to regulate the porosity in the combustible billet ETP by means of a shrinkage controlled during casting and curing. Since oxygen is quite effective tool Removal of residual impurities, the rabid part of their harmful manifestations can be eliminated. As a result of the interaction between oxygen and other elements, conductivity can be improved, increase the degree of annealing and the ability to molding. For example, in Fig. 7 Oxygen indication on the electrical conductivity of some copper varieties in an annealed state.

Fig. 7.. The effect of oxygen on the electrical conductivity of annealed copper

For a commercial wire with a purity of four nines (99.99%), the initial concentration of oxygen 200 ppm causes an increase in the conductivity due to the purification effect. After completion of the aforementioned response in a solid state state, the conductivity decreases linearly due to an increase in the volume fractions of copper oxides. In fig. 7 It is also seen that the conductivity of copper and ETP is about the same. Copper ETR, currently produced by continuous casting, is manufactured, for the most part, with an oxygen content in the range from 125 to 500 ppm. At a lower oxygen content, the tendency to the appearance of cracks at high temperatures is increased due to increasing the fragility due to the lack of oxygen and hydrogen. If the oxygen content goes beyond the boundaries of the specified range, the content of equilibrium copper oxides occurs. Consequently, the overall viscosity of the wire decreases, and the likelihood of cracks due to increasing the brittleness during the drawing increases.

Scrap

Copper blanks of higher purity are commonly used to make winding wires to which the most stringent requirements are presented. Therefore, high-purity electrolytic purified cathodes are recommended for such specific use. A variety of compounds associated with some industrial varieties ETP, of and varieties of copper flame (FRTP) are presented in Table 4. In the last decade for less critical applications (for example, wires for construction), the copper wire was made of copper waste (scrap) . Assuming that to reduce the content of the total impurity content, a certain type of purification in fire is used, may in this case obtain the electrical conductivity of 101% IACS. The percentage conductivity of the copper sample of the wire (% of IACS) was calculated by the Decisions of the Copper Standard (International Annealed Copper Standard) on the sample resistance at 20 ° C. When calculating, it is possible to use resistance of volume or mass. The foundry billet, which was made using a flame cleaning at the La Farga Lacambra plant in Spain, was fragmented on a rod mill and then processed into wire sections of a large length with the use of multi-frequency drawing plants.

Table 4.. Chemical composition Commercial varieties of copper ETP, Of and FRTP

Element	C1100 ETP	C11040 ETP	C11045 ETP.	C10100 OFE.	C12500 FRTP.
	PPM, Max	PPM, Max	PPM, Max	PPM, Max	PPM, Max
Copper,%	99,9	99,9	99,99	99,9	99,88
Tellurium		2	2	2
Selenium		2	2	3
Bismuth		1,0	0,5	1,0	30
Antimony		4	4	4	30
Arsenic		5	5	5	120
Tin		5	5	5
Lead		5	5	5	40
Iron		10	10	10
Nickel		10	10	10	500
Sulfur		15	15	15
Silver		25	25	25
Mercury		-	-	1
Cadmium		-	-	1
Phosphorus		-	-	3
Zinc		-	-	1
Magnesium		-	-	0,5
Oxygen		100-650	125-600	5

Improving the quality of blanks for the manufacture of wire

In recent decades, there has been a continuous improvement in the quality of copper blanks for the manufacture of wire, due to other things, the successful implementation of the methods of statistical control of the production process, Six Sigma (Six Sigma) and LEAN Manufacturing (inclined production line). We note several successful developments related to the recent past.

Non-destructive testing with vortex currents

In almost every line of continuous casting of blanks, electromagnetic methods of automatic control (using vortex currents) of the surface of the surface of the workpiece after hot rolling are used. In some control systems for detecting cracks arising at high temperature, a coil is used through which a hot blank inside the rolling installation. To ensure increased sensitivity, filling coefficients must be at least 60%. This contactless, non-destructive method is successfully used at high speeds of the rolling equipment. Wetting devices are usually necessary to prevent excess of excessive noise and vibrations. The ASTM standard provides recommendations for the practical application of this method. Upon the assumption that defects are located near the surface, the control equipment allows detecting bundle, cracks and foreign inclusions.

Removal of scale

As a result of the impact on the heated workpiece of the atmosphere on its external surface A thin layer of scale is formed very quickly (oxide containing bivalent copper) with a thickness of about 100,000 E (104 nm). Since the adhesion of the scale to the base metal at a temperature of about 800 ° C is very weak, its separation is carried out without difficulty. Therefore, high pressure pumps at the installation of roughing for spraying a rolling emulsion on a hot moving casting are used in the continuous melting lines of copper. Despite the fact that almost 90% of the scale can easily be removed under the influence of an emulsion sprayed under greater pressure, additional cleaning is needed to ensure high quality. In some large continuous casting lines that work in a complex with installations for cleaning copper, in hot rolling equipment, an aqueous solution of sulfuric acid and an aqueous solution for etching is still used. On the other hand, in most of the continuous melting lines and casting copper moving hot casting is placed in an aqueous solution of alcohol. Alcohol evaporates at high temperatures, and hydrogen is formed and carbon monoxide. These gases react with copper oxide on the casting surface, while the thin surface layer of copper is formed. Schematic representation of the methods of impact on the workpiece with sulfuric acid or alcohol for chemical removal or reduction of the thickness of the scale is given in Fig. 8. If the process of reducing the thickness of the scale is not communicated to the end, a thin layer of copper is formed on sub-sample copper oxides. The reaction time necessary to reduce the thickness of the scale layer by 5000 E (500 nm) is several seconds. Although other organic compounds can form gases that reduce the thickness of the scale layer, isopropyl alcohol (IPA) is the most efficient organicused in the production of copper wire.

Fig. eight. Removal of surface layers of oxides on a rod of etching in acid or with alcohol

Monitoring surface oxides and small fractions

The scale layers on the surface of the copper are highly abrasive and can lead to the formation of small solid inclusions on it, to wear a rattling filler, poor seabilities, frequent cliffs of wire and poor enamel adhesion with a naked copper conductor. The thickness of the oxides of one-two-bivalent copper is quantified by the method of electrolytic reduction of thickness using DC. When the casting method was obtained for the first time, a blank for the manufacture of a rod was obtained, the typical magnitudes of the thickness of the oxide scale lay in the range from 6000 to 8000 E. Currently, the brutal part of the rod manufacturers is able to produce products with a thickness of oxides of oxides less than 300 E (30 nm). Small factions of copper can be detected on the workpiece after hot rolled by the method of gravimetric analysis. After testing several different samples on the twist, the fallen inclusions are removed using ultrasonic vibration and then weighed after drying. The ratio between the weight of inclusions and surface oxides has the following form:

WF / WR × 16 -6 \u003d 8.73 + 0.493 × SO,

where WF is the weight of inclusions, WR - the weight of the workpiece, SO is the thickness of the film in angstroms. Since the oxide scale on the billet after etching is removed chemical method, the number of residual inclusions is often less than when cleaning the billet with alcohol

Forecasting and technology of the future

It is possible that the last decade was a period of the largest number of changes in the production of rods, wires and cables compared to any other period of its development since antiquity. Table 5 provides a list of important events related to copper and drawing related to history as a whole.

Table 5. Chronology of events in the history of mankind associated with copper and wire manufacture

Years	Event
BC
8000-9000	Opening a man of native copper
~5000	Beginning of the Wire Production History
~4600	Wire samples were made (found in 1901 n. E.)
4700-3800	Made bronze with melting copper and tin
4000	The Egyptians were signed with a thin metal sheet and stretched out through a hole.
3500	Copper wire made in Egypt
2900	Made wire fusion of wrought short pieces of wire
2750	The Pharaoh Necklace from Denbarab is made of oval gold plates connected by a chain of golden wire
2200	Wire made in China
2000	Wire made in India
1544	Clothes, woven from metal filaments weighing 36 pounds, found in the grave of the Roman emperor Neurisa
~1490	In the "Exodus" (39: 3) describes the manufacture of wires from thin metal plates with a hammer
1400	Greeks began to use iron
1000	Bronze wire began to do in Scotland (found during excavations in 1879)
800	Bronze wire rope found in Nivea (sample is now in the British Museum)
500	Made rope from bronze wire. Found when excavations Pompeii
400	In China, began to make wire ropes
our era
79	Pompei's destruction (in the Naples Museum is now there is a sample of wire with a diameter of 0.314 inches and a length of 15 feet)
300-400	Made a primitive filler for a wire broach in France
700	Making nails started in Belgium
700-800	Vikings in Norway used filters (assumed)
VI - X century	Venetsians and Italians used loophile boards for the manufacture of wire
1000-1100	Theophylus gave a description of a drawing board
1260	Wire made in Europe by cold drawing
1300	The concept of the damaged surface is introduced
1350	Rudolph from Nuremberg uses the Water and Wheel Machine for Wire Production
1370	Wire forging is still used in Nuremberg
1486	Leonardo da Vinci (?) Designed a rolling machine
1540	In Pyrotechnics, Vanuchcho Biringudzhio delivered a drawing of a wire mill
1556	Georgius Agrikola in the book "De Re Metallica" described copper production
1564	The loophile setting of this time is shown in the museum of the clock, in Paris
1600	Johan from Altene (Germany) began drawing steel wire
1624	Welding wire started in Sweden
1650	For the first time in America, a wire is made; High carbon wire made by drawing in Germany
1726	Flat wire for clothing (in Sweden)
1728	The roller is made using a corrugated roller in France
1754	Englishman Henry Court builds the first rolling mill for iron
1775	The first plant for the production of wire in Norwich, pcs. Connecticut
1820	Morse invented the telegraph, in Philadelphia, a firm for the manufacture of hats on the turns of the wire was opened
1821	For the year in the USA, 250 tons of wire made
1834	Three Wire Production Plants are open in the US with a capacity of 15 tons per year
1840	Varning makes the first rope of wires in the USA
1855	Brown and Sharpe offered a system of calibers
1858	American Wire Calibers Standard proposed by Brown and Sharpe, adopted by brass manufacturers Association
1863	Sorbi applied a microscope for the research of metals; Insider tried the way continuous casting of blanks
1867	Reincarnation begins the construction of the Brooklyn bridge
1886	Carbides are open in France and methods for obtaining them
1889	Patented coating steel copper
1908	Kulidge from G.E. Conducts laboratory testing installation on Welding Wires from Wolframa
1928	Filters from carbide began to be applied in the USA for drawing
1930	Founded Association of Wire Manufacturers
1948	Description of the characteristics of an annealed copper is represented by Cook Engineering
1965	Steel Wire Directory issued by the Wiring and Cable Manufacturers Association (WAI)

Wiring and cable production

The associations, acquisitions and acquisitions of producing companies will continue, leading to an increasing reduction in production volumes. Globalization will not weaken, it will spread to Asia and maintain the pace of distribution in North America. In many studies, a constant reduction in the requirements in the wires market for construction and cables is projected. Cheap wire imports will lead to a trading deficit of insulated wires in the United States.

Technology

The costs of research and development, as part of the profit, are reduced for several years, and it is likely that this trend will continue in the future. As a result, the lack of scientists and students prepared for work in the cable industry will be felt. However, there is no reason to believe that this will lead to noticeable changes. Simultaneously with the movement of production to Asia countries, supplying products from where lower prices will be observed and the outcome of technical talents in the same direction will be observed. The biggest part of the Asian countries invests money and resources in the infrastructure of their local universities, which will then usurp the technologies developed in the United States. Further improvement of production will continue as a consequence of focusing on developing new technological equipment. Computer simulation is a very useful tool that is available for some time, but it is difficult to find an application in this industry.

Alternative materials

A few years ago, high-purity aluminum began to be considered as a substitute for copper superconductors operating at cryogenic temperatures. However, in the near future, such a replacement is unlikely. On the other hand, significant commercial interest is manifested in optical cables. The use of copper in telecommunication applications over the past few decades has decreased. Optical fibers are successfully used both in extended networks and short transmission lines. Currently, the optical fiber is intensively implemented in subscriber access lines in telephone networks, in particular, in lines connecting local stations with distribution nodes located in close proximity to the subscriber. Installing optical cables for these purposes will be significantly intensed. For example, the cost of Verizon Communications (USA) on the replacement of copper cables in its telephone network is about $ 23 billion, which gives the company the opportunity to provide subscribers access to cable television and high-speed Internet. And the implementation of this project called FiOS will continue. Another famous company - American Telephone and Telegraph (AT & T Corp.) - upgrades its network, paving optical cables to the boundaries of most areas where residential buildings are concentrated, but the signals will be transmitted to the subscribers using the existing copper lines.

Production of blanks for the manufacture of rod

It seems that the foundry production in North America is no longer expanding. At the same time, the installation of several new systems continues in China and India. Specific long-term prospects for the development of this market are opened in Africa, where the hourly remuneration is low. From the point of view of technology development, the tasks to improve the quality of the surface of the wire will remain in the center of attention, including to reduce the number of extraneous inclusions and minimizing surface oxides. Priority will have work on improving non-destructive testing methods. As a result, such a method should be developed that would allow for continuous monitoring of Macopores in the workpiece. Both ultrasound and electromagnetic acoustic transducers work well in laboratory experiments and, therefore, are promising from the point of view of application in the future.

Copper wire

Improving the quality of the surface will be achieved as a consequence of increasing the quality of high-speed transmission of speech and data signals. Non-destructive testing methods will be used more often in the process of producing wire, including in the production of wire having a small diameter. The requirements for the plasticity of the material of the original workpiece will increase and effort continues to achieve a "zero" level of defects. Of particular importance will be given to the harmonization of standards and technical requirements as a result of growing globalization in industry. Currently, very stringent requirements are presented to wires for windings of pulsed magnets regarding the ensuring elastic follow-up, good properties Molding windings and high electrical conductivity. In addition, the requirements for the magnitude of the minimum tensile strength associated with the ability of wire to molding and the need to prevent excessive wire tension with high-speed winding formation are possible. The automotive industry decades are interested in the use of reduced diameter wires to reduce the weight of the machines. In the future, you can expect that it is such wires and will be made. Several comments regarding the use of copper wire with a purity of four nines for the manufacture of wires for industrial application. Despite the fact that copper is manufactured with a purity of six nine, however, in small quantities, its cost is extremely high and probably no need for it, if we are talking about most standard applications, such as electromagnets, wires and cables for construction and construction and construction Telecommunications. Moreover, the electrical conductivity of both materials is almost the same at the same temperature. The main advantage of the material of very high purity is the increased electrical conductivity at cryogenic temperatures. Therefore, it is unlikely that standards for copper will be distributed beyond the minimum current value of 101% IACS. Finally, it is appropriate to notice that now in the production of wires and cables there is a significant decline, but optimistic expectations regarding the nearest future have real bases.

Note. For the first time, this material was presented in the form of a report at the 77th Annual Wai Conference (Wai "S 77th Annual Convention), Klivalend, Ohio, USA, in May 2007, then in the magazine Wire Journal International, in June 2007 .: Horace Pops. "Processing of Wire From Antiquity To The Future"

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