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By B. J. Scheiner

A ferrous chloride-oxygen leaching system was investigated by the Federal Bureau of Mines as a means of re-covering copper and silver from a sulfide concentrate that had been pretreated to remove a majority of the antimony. The pretreated concentrate contained Cu, Ag, Pb, Zn, Sb, and As. Parameters affecting metal extraction, such as temperature, pressure, amount of ferrous chloride, and initial hydrogen ion concentration, were studied. Copper extraction of 98 pct was achieved by leaching 4 hours at 40 pounds per?square inch gage (psig) and 1000 ?C. Copper was recovered from leach solutions by cementation with iron, and the resulting ferrous chloride was recycled. Leaching the residue with cyanide followed by electrowinning recovered 99.7 pct of the silver. Iron, Sb, As, Pb, and S reported to the tails.

Jan 1, 1978

By J. Sadaki, G. Dodbiba, S. Murakami, T. Fujita, S. Matsuo, H. Ono, K. Okaya

Printed circuit boards (PCBs) from discarded personal computer (PC) and household appliances were crushed by mechanical crushing or water explosion to remove mounted parts. More parts were stripped from PCB for PC composed of epoxy resin than from PCB for household appliance composed of phenol resin. In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 1073K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. On the other hand, tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins by heat treatment at 723 to 773K in air atmosphere and screening of 0.5mm. Silica was removed and 70% of tantalum grade was obtained after more than 823K heating and separation.

Jan 1, 2011

By G. L. Hundley, D. N. Nilsen

The U.S. Department of Energy investigated the use of liquid-emulsion membranes (LEM) for the selective removal and recovery of metals such as copper and zinc from mine waste waters. This investigation included field tests of a mobile, pilot plant-scale, continuous-flow LEM system. The system was tested at copper mines with solutions containing from 100 to 1,400 ppm Cu, and at a zinc mine with a solution containing 115 ppm Zn. Typical results from the copper tests were >90% copper recovery, and zinc extraction from waste water also was typically>90%. Although all of these waste waters contained high impurity levels, pure products were produced. On several of these field tests, integrated systems were tested that resulted in recovery of metal by-products, selectiv~ precipitation of iron, and polishing to reach discharge targets for essentially all of the contained metals. In addition, some results are included from laboratory-scale tests.

Jan 1, 2000

By Guillermo J. Román

The precipitation of copper and zinc as cements from a copper alloys' spent pickling solution has been studied at laboratory and pilot scale, with the objective of designing an economic process to recover both metals and render a solution to be either recycled to the pickling process or treated in a standard fashion and produce a non-hazardous sludge. The sulfuric acid spent pickling solution already containing copper and zinc was used first to dissolve another solid residue originated in the copper alloys foundry to neutralize part of the acidity. The resulting enriched solution was treated separately with two reductants,; sodium borohydride and iron powder varying pH and excess of reductant under constant agitation. Under the best conditions, precipitation of over 95 percent of zinc and copper was achieved together with the reduction of lead and cadmium contents respectively. A process for the combined residues treatment is proposed.

Jan 1, 1995

By G. K. Manning, P. C. Rosenthal

USE of copper as an intentionally added alloy in steel and cast iron has rapidly expanded with-in the last fifteen years. It is estimated that in 1931 not more than 2000 tons of copper were so used; by 1941, however, this figure had grown to 13,000 tons. Tonnage figures during the war years have been restricted just as copper itself has been restricted, but copper-bearing cast irons and steels have played a part in the production of ordnance equipment. They are used in gun carriages, airplane landing-gear assemblies, scout cars, bulldozing equipment, army trucks, armor plate and many other instruments of war. These wartime applications have their counterpart in many peacetime applications; derricks, dredges, mine equipment, railway equipment, trucks, farm implements, automobiles, and tractors, all usually contain some parts made of copper-bearing steel or iron. An example of this is the Ford tractor which in 1940 contained over 300 lb. of copper-bearing steel castings. To this list should be added corrugated building sheet for exterior use most of which, at the present time, contains upward of 0.15 per cent copper. With the return to peacetime economy and the removal of wartime restrictions, it appears certain that copper cast irons and steels will find increasing application in civilian goods.

Jan 1, 1945

By Corale L. Brierley

Bioheap leaching, commercially applied for secondary copper ores and agglomerates, is rapidly gaining popularity. Bioleaching of chalcopyrite concentrates is imminent. Copper bioheap leaching encompasses the bioleaching of acidified and agglomerated coarse, secondary copper ore, stacked on permanent or on/off pads. The stacked ore is irrigated with raffinate containing bacteria. LME-grade cathode copper is produced by SX/EW. Low capital and operating costs, rapid start-up, environmental benefits, operational simplicity and a good performance record make bioheap leaching an attractive technology. This paper looks at the state-of-the-art of copper bioheap leaching and chalcopyrite concentrate leaching, the risks, the benefits, costs, bioheap performance and the future prospects of copper bioleaching.

Jan 1, 1999

By N. H. Emmons

(Canal Zone Meeting, November, 1910.) AN interesting development of copper blast-furnace construction has been brought about in adapting the blast-furnace to be a "burner" for sulphuric acid making. When the Tennessee Copper Co. first decided to construct an acid-plant, the standard type of brick-top furnace, supported by structural steel, was the only one in use at this plant. All the tests for temperature and strength of gas had been made on these furnaces, and had been satisfactory. When, however, the acid-plant was put on the flue, and the flue had to have a damper put in it to force the gas into that plant, troubles began. The furnaces were fairly tight, and for a few months the work was quite satisfactory., Fig. 1 shows the old type of furnace-top used at the start. It was soon found that this top would not stand the temperatures, particularly when dampered back, as was necessary to force the gas into the Glover towers. The structural steel, of which the furnace skeleton was constructed, warped and twisted so badly that it was not safe to use the furnaces. This effect is shown by Fig. 2, which is a photograph of old No. 4 furnace, after the brick-work had been removed. It became apparent that a new type of top was necessary and the engineering force was started oil the design of a new furnace-top, with the result that a low top, with brick-lined flues at each end below the feed-floor, leading to the main concrete dust-chamber, was constructed. This furnace, No. 7, is shown in Fig. 3. The charging-doors are made of cast-iron sections, three sections to a door, and three doors to a side. A door to the furnace was made of cast copper, but the heat was so great that the copper bent readily, due to the jarring of its * General Manager, Tennessee Copper Co.

Feb 1, 1911

By L. R. Bottomer, G. M. Leary

"The Copper Canyon property is located in the Galore Creek area of northwestern British Columbia. Porphyry copper-gold mineralization on the property is notable for its high gold content and close spatial relationship with a distinctive suite of high level syenitic and monzonitic intrusions, and pseudoleucite-bearing volcanic country rocks. The style of alteration and mineralization is similar in many respects to the nearby Galore Creek deposits.The current geological resource of 32.4 million tonnes grading 0.75% Cu, 1.17 g/ t Au and 17.1 g/t Ag is insufficient to support a mining operation, but definition of additional reserves combined with improved transportation infrastructure in the region may change this in the future. The climate, topography and proximity to an active glacier indicate that the most likely production scenario is an underground bulk mining operation, with the ore being milled offsite.IntroductionThe property is located at 57°07' North latitude, 131 °21' West longitude, on NTS sheet 104G/ 3W, approximately 160 km northwest of Stewart and 90 km south of Telegraph Creek (Fig. 1). The Galore Creek camp and airstrip are located 6 km to the west. Current access to the property is via helicopter either from Galore Creek, or from the Bronson Creek airstrip 32 km to the south-southeast.The deposit occurs within the Boundary Ranges of the Coast Mountains, on the north side of the east fork of Galore Creek, which flows northerly into the Scud River and thence westerly to the Stikine River.Topography is rugged. In the deposit area, elevations range from 1130 m to 1750 m. Valley glaciers and permanent snow and ice fields are characteristic of the region at these elevations, and at its southern limit, mineralization is truncated by the East Fork Glacier.The property is entirely above the treeline, and except for areas of moraine cover and talus slopes, outcrop is abundant."

Jan 1, 1995

By J. J. Bean

The development drilling program of the Copper Cities mine indicated that the molybdenum content of the ore would be about 0.011% MoS2' The molybdenum content of the Miami mine at the same time was about 0.025% MOS2' The Miami mill had a very successful molybdenum operation which used bleeder turbine steam from the Miami power plant for the steaming operation. The much lower grade of the Copper Cities ore, the absence of a source of low cost steam and the use of sodium aerofloat as the copper collector which Miami experience indicated did not respono readily to the steaming technique made very doubtful the success of a similar operation at Copper Cities. However, the relatively few pounds of copper that could be recovered from the low grade Copper Cities heads made very desirable the recovery of the molybdenwa,as a source of additional revenue. Accordingly, shortly after the Copper Cities mill began operation, a research program was instituted to develop a suitable method of molybdenum recovery. This program explored first, the successful steaming process then in use at Miami and as expected, found it unable to decompose the sodium aerofloat copper collector. The known chemical depressants were then tried without much encouragement. Finally the copper concentrate was dried, not roasted, to 2-3% mOisture and this along with sodium ferro-cyanide and cyanide resulted in sufficient copper depression that a final molybdenum concentrate containing 1.0% CU could be made. The bench scale testing was followed by pilot plant testing. Sixteen

Jan 1, 1972

By Arthur Notman

IN VIEW of the wide publicity given to the charges by the Couzens Committee of the United States Senate of discrimination by the Bureau of Internal Revenue in favor of the copper companies, it becomes a matter of interest to consider the basis for these charges. The point to be determined is whether they rest on a foundation of fact or are purely and simply matters of opinion. The whole question boils down to the purpose of the Tax Law as applied to mines, which is to afford the same protection to them as provided for all other taxpayers, namely: that they were to be allowed to pay back as depletion to their owners the values of their properties as they existed or were estimated to exist on May 1, 1913, free from tax. To determine these valuations it was? necessary to select from a wide range of possibilities a set of values for a number of essential factors.

Jan 1, 1925

By W. A. Yuill

A process has been developed for increasing the grade of chalcopyrite concentrates from about 25 percent copper to about 60 percent copper. The concentrates are treated with two steps of autoclaving and then by flotation. Because of the lower associated weight, copper in the concentrates could be shipped and smelted at less cost than untreated concentrates. Use of the process can also increase overall yield from an orebody if a lower grade concentrate is sent to enrichment than would be sent to a smelter. Potential applications of the process would be for treating concentrates that must be transported a long distance for smelting or for treating concentrates so as to increase the capacity of a smelter.

Jan 1, 1984

By T. Yeomans

NVI Mining’s Myra Falls operation is a forty-year-old underground mining operation feeding a 4,000 metric tonnes per day concentrator. The current mill, built in 1985, was designed to process a massive sulphide ore-body. This orebody, known as the HW, contains about 50% pyrite. Minerals of value are chalcopyrite and sphalerite, with precious metals occurring in all mineral types. By 1997, mining of a new ore-body, known as Battle-Gap, commenced. Mineralogically complex, the new orebody contains about 15% pyrite copper minerals, including primary chalcopyrite and secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite. Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected. Following significant metallurgical test-work, a new, fully sequential copper-lead-zinc flotation flow sheet and reagent scheme was developed. This sequential flow sheet was progressively installed and commissioned during 2006. Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, while increasing copper recovery by 10%.

Jan 1, 2009

By Trevor Yeomans

"NVI Mining’s Myra Falls Operation is a forty year old underground mining operation feeding a 4000 mtpd concentrator.The current Mill, built in 1985, was designed to process a large massive sulphide ore-body. This ore-body, known as the “HW”, contains about 50% pyrite. Value minerals are chalcopyrite, and sphalerite, with precious metals occurring in all mineral types.By 1997, mining of a new ore-body, known as “Battle-Gap” commenced. Mineralogically complex, the new orebody contains about 15% pyrite, copper minerals including primary chalcopyrite, secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite.Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected.Following significant metallurgical testwork, a new fully sequential copper-lead-zinc flotation flowsheet and reagent scheme was developed.This sequential flowsheet was progressively installed and commissioned during 2006.Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, whilst increasing copper recovery by 10%.INTRODUCTIONNVI Mining operates the Myra Falls Operation near Campbell River on Vancouver Island, BC. The complex has been in operation since 1966 with mining being predominantly underground. One unique feature of Myra Falls is that the mine operates within a BC Provincial Park.In 1985, a new large massive sulphide ore-body (HW) had been defined, and metallurgically tested. A new concentrator was built based upon this massive pyrite, chalcopyrite, and sphalerite mineralization producing copper and zinc concentrates by conventional flotation methods."

Jan 1, 2008

By Mauricio Guimarães Bergerman

At the regrind or secondary grinding stages of base metal ores, the concern about energy efficiency is usually extremely important. In general, the specific energy consumption at this stage is higher than during the primary grinding stages. In addition, a tendency of finer grinding has been observed in the new projects of metallic minerals, due to the finer mineral liberation, which leads to increasing capital and operational costs. At Vale?s new copper projects in Brazil, regrind sizes with a P80 of approximately 40 to 20 µm have been necessary. Conventional ball mills, adequate for primary grinding, usually bring about low energy efficiency with products bellow 50 µm. Vale is using the vertical mill on its copper projects ? Sossego and Salobo, in order to optimize the regrind of rougher concentrates and reduce energy consumption. This paper presents the results of industrial surveys carried out on the Vertical mill circuits of Sossego plant during its initial years of operation, and compares these results with the design criteria and laboratory regrind tests used for the mill scale up. Keywords: grinding, regrinding, copper, vertical mill, stirred mill

Sep 1, 2012

By Toshiyuki Kawai

Copper concentrate smelting directly in P-S converters was started at Onahama Smelter in 1983. Thereafter, the tonnage of concentrate smelted through the P-S converters increased, such that by 2002, it equaled the tonnage smelted through the reverberatory furnaces. In 2003, 56% of the total copper concentrates treated at Onahama Smelter were processed directly through the P-S converters. Technical improvements are reviewed and advantages of direct smelting in P-S converters are reported.

Jan 1, 2005

By Hare S. M, Lumsdaine I, O&apos

Converter slag assaying 3.7 per cent Cu is produced by Mount Isa copper smelter at a rate of up to 180 000 tonnes per annum.Priority is given to the processing of ore, however concentrator capacity periodically exceeds that of the mine and the opportunity is taken to treat converter slag. It is processed in batch campaigns, typically through the Copper Concentrator, but the Hilton Concentrator has also been used. Slag and ore are kept as separate as possible, since each has an adverse effect on the flotation performance of the other.

Jan 1, 1993

By E. N. Mounsey

Ausmelt Technology was selected by Bindura Nickel Corporation (BNC) as the basis for a new copper circuit to process nickel plant copper leach residue to blister, anode and finally cathode copper and recover PGM values at the Bindura Smelter Refinery (BSR). The process selected, based on Ausmelt Technology to smelt and convert the residue to matte and blister copper and produce a discard slag, is novel incorporating smelting, converting and slag reduction process steps in a single Ausmelt vessel. The process demands a high quality blister copper product with low levels of arsenic and nickel. This paper reviews the project and the initial operational results to the end of 1997 of the Ausmelt Top Submerged Lancing (TSL) smelter and discusses the implications for the wider TSL converter market.

Jan 1, 1998

By Kim Fagerlund

Boliden Harjavalta Oy operates a copper smelter in Finland, which is based on flash smelting together with Peirce-Smith converting of copper matte. This paper reviews a case study when a high arsenic feed mixture was successfully eliminated in order to guarantee the anode quality. Based on theoretical and practical knowledge in slag chemistry at Outokumpu Research, the CaO-fluxing practice was introduced. Description of a thermodynamic simulation using MTDATA and implementation of the results into converting practice is given. Results showed that the impurity fluctuations in raw materials could be effectively controlled by efficient utilization of different slag chemistry.

Jan 1, 2005

By Lauri Holappa

Copper converting is mostly performed in Peirce-Smith converters. The process is still very similar to the original one developed in the early 20th century. It is a batch process in a horizontal cylindrical reactor with air blowing via tuyeres along the length of the reactor side. The Peirce-Smith converter has its roots in Bessemer's inventions in the 1850's as he tested both horizontal and vertical vessels for steel converting. However, for steel making a vertical pear-shaped converter with air bottom-blowing was established. In the course of time, there was a distinct necessity for oxygen usage instead of air due to harmful effects of nitrogen to steel properties and its cooling effect. In-bath blowing of oxygen did not succeed, however, and top-blown oxygen converter with oxygen lance (LD or BOF) was first developed in he 1950's and emerged rapidly to a dominating position. Somewhat later oxygen bottom-blowing via special shrouded tuyeres was developed (OBM or Q-BOP) but has attained only fractional share. Bottom-blowing technique had, however, impact on the current combined blown converters which adopted the benefits of both top and bottom blowing. In copper converting Peirce-Smith type converters have kept their position until today although new processes have been introduced and at least few of them seem to be emerging. In one respect copper converting has a clear leading position i.e. in the progress of continuous converting processes (Mitsubishi, Ausmelt). These processes utilise top-blowing lances instead of in-bath blowing tuyeres. A different principle for continuous converting is flash converting by Kennecott Outokumpu, which makes smelting and converting independent of each others. Solid ground matte is used as a feed for flash converting in a reactor shaft similar to Outokumpu matte flash smelting. A comparable process has been presented by Inco too. The paper discusses principal physico-chemical and process technical similarities and differences in copper and steel converting. Although these processes are metallurgically quite different it seems that during the modem history of ferrous and non-ferrous metallurgy, starting from the 1850's, the exchange of knowledge between these disciplines has been quite intensive. In long-term perspective, many similarities in the development can be found but also divergences due to different ambient circumstances.

Jan 1, 2003

By R. B. Nourse, R. Hundermark, B. Masters, H. Joubert

The new 30 MVA slag cleaning furnace at Waterval Smelter, Rustenburg Platinum, South Africa, has been in operation since 10 March 2003. The furnace design and operation face a number of challenges including a wide variety of feed materials and resulting bath conditions. Furnace feed varies in combinations of granulated Waterval Ausmelt Converter Slag (WACS), hot fed Peirce-Smith converter slag, concentrate and reverts. Coke is added as reductant. The resulting slag composition varies considerably and regularly. For the case feeding WACS an almost pure fayalitic slag (60%+ FeO, 30%+ SiO2) with a very low viscosity results. Due to the widely varying slag conditions, including a superheated fayalitic slag with high fluidity, a robust sidewall design is required adjacent to the slag bath. For this reason the furnace sidewall is equipped with Pyromet's MAXICOOL® high intensity copper cooling system. The design and installation of the copper coolers as well as tap holes are discussed. To cope with the variation in bath conditions and high slag superheat (350°C when tapped at 1650°C), the copper coolers are capable of removing peak sidewall heat fluxes above 500 kW/m2. Feedback is included on the performance of the Pyromet MAXICOO® copper cooling system for the first two years of operation. The paper further includes an overview on the design and performance of the tap holes, furnace shell, furnace roof and copper slag spouts.

Jan 1, 2005