copper ore processing in Palabora Mining South Africa

Copper ore processing in Palabora Mining South Africa decided to extend the underground mining of copper. Below the surface mining blocks with a daily production of 30,000 tons is an acceptable way of economically maximize the recovery of the deposit. This will facilitate the copper ore processing in Palabora Mining South Africa were at least able to walk for 20 years. When mining the copper deposits below the surface, it is planned to increase further the efficiency of mining process of copper using modern equipment automation and tele-controlled machine. The aim is to extend the daily operations, increase productivity, integrating data acquisition and diagnostic features and increase the level of automation. On the one hand, the system is designed to provide comprehensive information on the operations throughout the mine to management. At the same time, the operating personnel in the control panel needs direct control and monitoring of underground mining activities.

Underground Copper Ore Stream in  Palabora Mining South Africa

       Copper ore from the underground block-cave mine – less than 300mm in size – is conveyed to two stockpiles, each feeding two separate, autogenous wet-grinding circuits. These in turn, each comprise a 9.75 meter-diameter tumbling mill rotated by 2 x 3.5 MW drives. Large rocks impact, scrub and attrition against each other, reducing their size, which results in the liberation of the copper sulphides.

      Mill products are sized by vibrating screens to produce coarse feed to the pebble crushers. Fine particles of 0.3mm removed from the circuit as the main product of milling up to 30,000Tpd (tonnes per day?) Product rough cyclone underflow is recycled. Cyclone overflow from both circuits is then pumped 1.5 kilometres to the secondary milling plant (SMP) where the ore is further ground to less than 0.15mm, using steel balls in up to five parallel 1.2 MW milling circuits. Secondary milling has been applied since 2003 by reconfiguring the existing equipment. This is to improve the liberation and recovery of copper in underground ore grade higher.

      Chemicals are added to allow the copper sulfide particles to separate from the fine ore particles through the process of ‘froth flotation’. A xanthate collector metered into the slurry and adsorbs to the particles to the copper sulfide to increase their hydrophobicity. Frother also added to produce a stable foam. The flow is then divided between the parallel rows of flotation cells. Each row contains several agitator to maintain the suspension and for the air to disperse the slurry. As the air bubbles rise to the surface of the cell, the copper mineral particles attach hydrophobic privileged to bubble and form a stable foam, which continues to overflow into launders. The process is then repeated two more times to recover almost 90% of the copper feed to only 2% of the weight of feed to produce 32% of copper sulphide concentrates. The latter is then pumped to the dewatering plant. 

Conventional Process Leaching Of Copper in  Palabora Mining South Africa

Transition to underground mining has allowed 50,000 tpd of destroying conventional milling and flotation capacity. Copper and magnetite recovered on behalf of Foskor (neighboring mining company) by a 20,000 tpd ore processing toll marginal of stock from open pit operations. These Conventional process leaching of copper are also applied to underground ore available in more than autogenous grinding capacity.

      A main rotating crusher is used to reduce the dump material from 200mm to 1500mm down in size before relaying to one of the two stocks. Feeders and conveyors transport the ore to a two-stage dry crushing plant where two secondary crushers reduce the size to below 50mm. Additionally, 5 tertiary crushers further reduce the ore to below 20mm, operating in closed circuit with vibrating screens. Crushing plant product is then conveyed 1.4 kilometres to fill any one of six fine ore bins, each one feeding six rod mill flotation sections, all operating in parallel. Certain sections are used for wet grinding marginal ore to below 0.3mm, followed by a copper flotation process similar to that used for the underground ore. Concentrate is pumped to a dewatering plant, while magnetite removed from the tailings thickening and pumping before the final product for Foskor for flotation of phosphate

       A third secondary crusher-feed stockpile is reserved for ‘minus 200mm’ underground ore that can be diverted by means of a moveable chute and transfer conveyor. Underground ore is batched through the secondary crushing plant and directed to the fine ore bins. Each section is able to grind 6,000 Tpd of ore finer than 0.2mm before froth flotation.

 Dewatering, Magnetite Production And Tailings Disposal In  Palabora Mining South Africa

Concentrated sludge is pumped to a thickener using a vacuum filter disc and rotary dryers coal successively removing water to reach 8% residual moisture. Dryer product weighed by the belt scale and sample before submission to the receiving warehouse smelter. Flotation tailings from the second circuit and conventional Autogenous pumped into magnetic separation plant, where a rotating magnetic drum magnetite extract 16% by weight of the slurry. Nine three-drum magnets are used for the three stages of upgrades to produce up to 5,000 TPD of 98% pure magnetite concentrate. The concentrate separated into two size by rising currents of water (elutriasi). On average, 600 TPD fine magnetite directed to classifier overflow, thickened, filtered and stockpiled prior to the delivery of domestic heavy media consumers who are used to upgrade coal. The majority of magnetite to be transported to underflow classifier and then pumped either to drying of the desert to the fence and export, or dam large magnetite deposit, depending on the sales commitment. Export magnetite is used for the production of iron and steel.

      After removing magnetite, ore tailings underground flows to three parallel 90 meter diameter tailings thickener to recover and reuse water, while the combined underflows pumped to various points around the perimeter of a large tailings dams. The dam wall is maintained at a higher level with coarse solids beach. Fines flowing into the central pool, where the clear water contained by the siphon and stored in a dam the water back for reuse in the process.

Palabora Mining Companies In South Africa

      Palabora Mining Company was founded in South Africa in August 1956. The company is owned and managed by Rio Tinto. 57.7% owned by Rio Tinto and Anglo American has a 16.8% stake. On September 5, 2012, the two companies announced their intention to sell their respective interests in Palabora. On December 11, 2012, Rio Tinto announced that it reached an agreement with a consortium binding sales that are committed to the sustainable management continuously from Palabora. The consortium is comprised of South Africa and China entity led by the Industrial Development Corporation (IDC) of South Africa Limited and China’s Hebei Iron & Steel Group. The sale agreement was concluded in July 2013, and the company name changed from Palabora to Palabora Copper Mining Company (Pty) Limited.

       Located 360km north east of Pretoria, close to Kruger National Park, Palabora is South Africa’s leading copper producer and also a major source of vermiculite and baddeleyite (zirconium oxide). The majority shareholder in Palabora Mining Co. is Rio Tinto plc (57.7%) and Anglo-American. Palabora Copper (Pty) Limited and beneficiates extract copper and other by-products in Ba-Phalaborwa area of Limpopo Province. Palabora just fine copper producer South Africa and supply the local market with 85% of copper needs.

       Copper operations consist of underground mines, a concentrator, a copper smelter with anode casting facilities and associated acid plant, an electrolytic refinery tank house, rod casting plant, magnetite separation plant and plant by-product recovery. Vermiculite operation comprises open pit mining operations and recovery plants. Open-pit mining began in Palabora in 1964 and ended in 2002 when the economy reaches a depth hole final. The development of an underground mine to work ore remaining under the bottom of the pit began in the last years of open pit mine production, at a cost of about $ 465m, with the prospect of life of over 20 years in the underground operation. Integrated copper production complex has a metal-refining capacity of 135,000t / y, despite the change to underground mining means that some of this capacity is now redundant. Operation employs about 1,800 people.

      Palabora containing magnetite, vermiculite, apatite, zirconium, titanium and uranium and copper. Deposit is hosted in a complex consisting of alkali particularly frozen pyroxenite with events pegmatites, foskorite and carbonatite. Three separate mineralized zones have been identified in outcrop 20km² complex surfaces, from the north is rich in phosphates and the center (Loolekop) zone forms the basis for this Palabora copper production. Copper ores are hosted in carbonatite pipe where the value is usually concentric with the highest value (1.0% copper) at its core. High grade mineralization extends down the center of the projected end of the pit open floor. Underground mine has been developed on the proven reserves 225Mt at 0.7% copper, plus the possibility of additional reserves of 16Mt grading 0.49% copper. At the end of 2005, proven and probable reserves of 112Mt levels reached 0.56% copper, representing a significant reduction of the tonnage and grade quoted previous year. Rio Tinto recorded a US $ 161m asset write-down in the 2005 accounts to reflect this.

       Throughout the 35-year life, Palabora often at the forefront of technological development of surface mining. The main feature is the use of trolley-assist systems for haul trucks out of the pit, to save diesel, and it was one of the early users both in pit crushing and computerized despatching trucks. Open pit fleet consists of about 20 Euclid and Unit Rig trucks, with the four P & H 2100XPA and 2,800 shovel. Cargo truck monitored using Pit control systems on-board overload the shovel, associated with Modular Mining Systems’ despatching and monitoring program. Fuller-Traylor rotating in-pit crusher, with a nominal capacity of 5,000t / h, feeding the main conveyor that carried a 1.8-width crushed ore drift up on the pit wall to the rough surface of the ore stock.

       Underground mine is block caving operation, the first such system to be used in metal mining in South Africa. With the introduction of underground operations, ore output had fallen from the 82,000t / d achieved in the previous open pit to 30,000t / d. However, the transition to underground production has proved problematic, especially in relation to the handling of large ore in drawpoints, and I have struggled to meet production targets. Average output during the end of 2003 was about 20,000t / d, and additional secondary breaking system is being built to help alleviate the bottleneck drawpoint.

       Shaft sinkers contracted to install the service shaft and axle production in the main-1,280m, while RUC Mining Contractors have carried out underground development. This includes driving around 36km of tunnels plus the underground crusher station, ore handling infrastructure and weaken level to block the first cave, located 500 m below the base of the final hole. Destroying the station was equipped with four ThyssenKrupp 900T / h double-toggle jaw crusher feed conveyor which connects to the shaft 1.32km production.

       Palabora employs one of the most complex recovery circuit installed in each copper mine, producing eight metals, minerals and chemical products in about 20 different varieties and grades. The complex includes a concentrator, a copper smelter and refinery, is now capable of producing 135,000t / y of copper plus by-product. Phosphate-rich tailings sent to Foskor, while Palabora sells its own copper, precious metals, nickel, zirconium, magnetite and vermiculite in domestic and world markets.

Copper Smelting Process At Palabora Mine South Africa

 

      As a first step copper smelting process At Palabora Mine South Africa, dried copper concentrate is blended with fine quartz flux and process materials, which are recycled from upstream. This copper smelting process is then poured into a continuous basis, with coal reverberatory furnaces, as well as operate up to 1400 ° C. The resulting melt will separate into two layers on the hearth furnace The denser molten matte layer captures the copper-iron sulphides below the unwanted uppe r slag layer, which is skimmed off periodically via skim bays and launders into large pots destined for rail transportation to the slag stockpile..

      Then process of copper matte with a copper content of 42% is tapped periodically through launders open into a large ladle, which will be directly transferred by rail and overhead crane into one of the three furnaces oblique converter. This copper smelting process are operated batch-wise, by blowing hot air through the matte to oxidise the sulphur and the iron, and then adding silica flux to form an iron-rich slag before returning it to the reverberatory furnace. After all the iron content from copper smelting process has been lost and, air is blown further without residual flux so that oxidize sulfur, and ultimately produce blister copper which is 98% pure. The converting process is exothermic and the excess heat is used to melt internal recycle materials and copper scrap from the refinery..

      Blister copper is then transferred to one of three anode furnaces, where the last traces of sulphur are removed by blowing air through the molten metal. This is followed by an injection of hydrocarbon fuel to reduce oxygen to very low levels. 99.5% copper is cast into copper anodes by means of a single rotating anode casting wheel. Anodes are hoisted into water quench tanks and racks for sorting and cooling; and then transferred by rail to the copper refinery. A ‘melting’ or ‘holding’ furnace is used to supplement copper production process by smelting process anode scrap that has returned from the refining process.

      Off-gas from the reverberatory furnace passes through two waste heat boilers and a balloon flue before it reaches a final process of cleaning by electrostatic dust precipitation. The flue dust is returned to the furnace and the low concentration off-gas can be discharged directly into the atmosphere via a 152 meter high concrete stack. It can also be treated in the wet gas scrubbing plant, if the precipitator is off-line. In this instance, once scrubbed, the off-gas is released to the atmosphere via a 70 meter high clean gas stack. Steam generated by the waste heat boilers is used to pre-heat primary combustion air for the coal pulverisers and to direct secondary air to the furnace. Excess steam is used to drive a 9.6 MW turbo-generator. Higher strength off-gas from each of the converters is passed through separate electrostatic precipitators for gas cleaning. The gas is then treated in a single contact sulphuric acid plant to produce 98% sulphuric acid for sale to the domestic market.

COPPER

COPPER 

Copper metal is a conductor of electricity and heat tool.A good thermal and electrical conductivity is very high. pure copper has a rather gentle and soft nature. So nice to use as a thermal conductor, a conductor of electricity, building materials, and various metal alloy constituents. Copper is also used for various purposes household appliances, to the biomedical component. Copper can also be combined with other metals to form alloys such as bronze. But we must also be careful of the nature of this toxic metal. This can occur when copper accumulate in the body due to the use of copper cookware. Elements Cu excess can damage the liver and cirrhosis spur.

Copper thinking about the symbol Cu and atomic number 29. In the Roman era, have a lot of copper in the mines and the most famous come from Cyprus, hence the origin of the name as сyprium metal, "metal of Cyprus", later shortened to сuprum. copper compounds commonly encountered as copper (II) salts, which often gives a blue or green color in mineral rocks at birth.

Copper mineral often formed in the oxidized zone and in the form of sulfide ore. If within a stone wall there are a lot of lime carbonate in the ore gangue which is the downward migration of metal sulfates can be predicted is the original copper which is a product of a general change of copper sulphide ore or greenish blue colored. In the oxidized zone of sulfide deposits of mineral water is sulfuric acid and iron sulfate solution. Copper sulphate in solution reacts with the carbonate or carbonate in acid solution, precipitation of carbonates such as:

READ MORE >>> COPPER ORE