Copper refining method
SUBSTANCE: method involves preparation of charge, its melting and oxidation of the obtained copper melt. Charge is prepared by classification of copper scrap and its cleaning from tin and lead solder, oxidation of copper melt is performed by batch supply to the melt of NaOH sodium hydroxide in the quantity of 0.5-3 wt % of the charge weight with simultaneous blowdown by means of oxygen-containing gas.
EFFECT: reduction of content of undesirable impurities in copper scrap melt; improvement of refining degree.
3 cl, 1 tbl
Method of refining copper relates to the field of non-ferrous metallurgy and can be used for fire refining of copper scrap, mainly used for electrical purposes, polluted, mainly by impurities solder and foreign inclusions.
Known "Method of fire refining of copper" by the request of EN No. 2007126129 from 09.07.2007, publ. 20.01.2009, IPC SW 15/14 (2006.01), including the melting of the copper-containing material with the addition of a flux, which includes iron and silicon oxide., the oxidation of the copper melt with the addition of fluxes in amounts corresponding to a mass ratio of SiO2:Fe=1,2...1,5, with a mass fraction of the flux from a mixture of 0.3...0.4% and the separation of slag from copper.
However, this method is applicable only when substantial content of impurities, since the introduction of iron in the molten copper, complicates the process, as subsequently leads to the necessity of its removal.
Known "Method of refining copper and copper alloys (options)" on the application of EN No. 2005135994/02 from 21.11.2005, publ. 27.05.2007, IPC SW 15/14, SS 1/02, including the melting of the charge in the furnace with the cover flow to the surface of the melt through a lance gaseous oxidant and subsequent recovery in the melt at the melt surface between at least two lances, set the frame and the area of the inner surface, costall the ment of 0.3-0.5 surface area of the entire melt, which is placed in refining flux, and when reaching the oxygen concentration in the metal is not less than 0.8 wt.% the gaseous oxidant stop, lances raised, providing free movement of the frame with flux on the surface of the melt; or, in this case, the gaseous oxidant to carry out the melt surface inside the frame, and refining flux is placed on the other surface of the melt, and, upon reaching the oxygen concentration in the metal is not less than 0.8 wt.% the gaseous oxidant stop, lance and raise the frame, ensuring the distribution of flux across the surface of the melt; as a gaseous oxidant use oxygen, or a mixture of water vapor with air, or a mixture of saturated hydrocarbons with air; as the ultimate hydrocarbon use methane; as a refining flux, a mixture of salts of alkali and alkaline earth metals and silica.
This method is applicable only if the refining furnaces, which allow the frame to the melt surface, mainly in the furnace crucible type.
The closest is "the way of the fire refining of copper" in patent RU No. 2391420 on 24.06.2009, publ.: 10.06.2010, IPC SW 9/10 (2006.01), SW 15/14 (2006.01), which includes the melting of the copper-containing mA the materials containing silicon oxide, with flux, and iron, further oxidation of the obtained copper melt at a temperature 1220-1240°C, with the addition of a flux containing aegirine concentrate composed of aegirine, and the silicon oxide - SiO2with the following ratios, wt.%: concentrate - 75-15%, silicon oxide - 25-85%, and separating the slag from the copper melt.
This method is also applicable when significant contamination with impurities of the copper melt. Aegirine concentrate contains significant amounts of iron oxide, which is undesirable due to the need for further removal. In addition, the application produces an acidic slag, adversely affecting the lining of the furnace, as a rule, basic or neutral.
The goal is to reduce the content of undesirable impurities in the melt of copper scrap, mainly used for electrical purposes, polluted, mainly by impurities solder and foreign inclusions.
The problem is solved owing to the method of refining copper, including batch preparation, melting and oxidation of the obtained copper melt, while the mixture is prepared by sorting copper scrap and cleansing it from the tin and lead solder, oxidation of the copper melt lead by batch feeding to the melt of sodium hydroxide NaOH in the amount of 0.5-3 wt.% by weight of the mixture with simultaneous produce the oxygen-containing gas; after each purge control chemical composition rathinasamy copper; the calculated amount of sodium hydroxide NaOH, distribute the blow.
The technical result is to achieve a degree of refinement that allows you to get commodity copper quality up to the mark M0 GOST 859-2001, due to portions of the feed to the melt of sodium hydroxide NaOH, in the amount of 0.5-3 wt.% by weight of the mixture with simultaneous blowing of oxygen-containing gas, which can reduce the content of undesirable impurities in the melt, at times, for example: Sn (tin) and Fe (iron) to 10, Pb (lead) up to 4, Sb (antimony) to 2. The data are summarized in table.
The method is as follows.
Cook the mixture, filtering from scrap impurities from foreign metals and alloys, and nonmetallic impurities.
After melting of copper-bearing materials in the melt, portions, or on the surface of the melt, served sodium hydroxide (NaOH) in an amount of from 0.5% to 3% by weight of the mixture, depending on indicators of contamination of metal impurities. At the same time the melt blown oxygen-containing gas (in the particular case - air), to oxidize impurities and simultaneous stirring of the melt.
The total required quantity of sodium hydroxide from 0.5% to 3%, determined empirically, on the basis of the experience is imentally data distribute the number of operations of the purge, which is held in conjunction with the introduction of NaOH.
After each purge control chemical composition rafinirovannogo metal, and based on Istochnik data, decide on the continuation of the operations of the introduction of NaOH and purging, or about the end stage of refinement and transition to a drain of the slag.
Upon completion of these operations the melt to stand, before the formation on the surface of a melt of molten slag having a low viscosity, which is a mixture of copper oxide and oxides of impurities. The slag from the surface of the melt is removed in any convenient way, for example by draining, or on the surface of the melt serves alkali metal polyphosphate, resulting slag is transferred into the solid phase, and it is removed mechanically.
After removal of the slag, restore (rascist) melt any known method: the flow in the melt wet logs (irritation), or blowing natural gas, or the introduction into the melt mixture of heavy hydrocarbons, periodically controlling the melt to obtain a satisfactory, below 300 ppm., measure the oxygen content in the melt.
The proposed method has proven its effectiveness during fire refining of copper scrap for electrical purposes, polluted, mainly by impurities solder and outsiders, including enemy, through the use of sodium hydroxide, can reduce the content of undesirable impurities in the melt, at times, for example: Sn (tin) and Fe (iron)to 10, Pb (lead) up to 4, Sb (antimony) to 2.
|Original content||The final content||The degree of refining|
The technical result is to achieve a degree of refinement that allows you to get commodity copper quality up to the mark M0 GOST 859-2001, provided the relevant preparation charge, and the slag has a low viscosity, which facilitates its removal.
1. Method of refining copper, including batch preparation, melting and oxidation obtained the region of the melt, characterized in that the mixture is prepared by sorting copper scrap and cleansing it from the tin and lead solder, oxidation of the copper melt lead by batch feeding to the melt of sodium hydroxide NaOH in the amount of 0.5-3 wt.% by weight of the mixture with simultaneous blowing of oxygen-containing gas.
2. The method according to claim 1, characterized in that after each purge control chemical composition rathinasamy copper.
3. The method according to claim 1, characterized in that the calculated amount of sodium hydroxide NaOH distribute the number of operations of the purge.
SUBSTANCE: solid sodium bromide is loaded in heated vessel, fused salt is pouted on its surface and heated. Molten mix is mixed and discharged from said vessel as-fused. Fused salt is pouted on sodium bromide surface at weight ratio of 1:(0.26-0.30). Said fused salt represents waters of electrolytic production of magnesium and chlorine, say, used electrolyte. Note here that said heated vessel is composed of continuous-action stationary carnallite furnace mixer, furnace hearth being heated to 300-370°C. Fused mix is mixed for 10-15 min. Produced flux may contain the following components at the following ratio: 9-20 wt % of NaBr, 4-9 wt % of MgCl2, 60-70 wt % of KCl, 12-24 wt % of NaCl, 0.7-4.0 wt % of CaCl, and not over 2 wt % of H2O.
EFFECT: higher purity of magnesium or its alloys, reduced formation of slag.
6 cl, 1 ex
SUBSTANCE: flux contains calcium oxide, aluminium oxide, and also partially silicon oxide and magnesium oxide in the form of slags from production of carbonaceous ferrochromium and silicocalcium, the missing magnesium oxide is introduced in the form of baked magnesite, the missing silicon oxide - in the form of quartz sand. At the same time the components are taken at the following ratio, wt %: slag of carbonaceous ferrochrome production 33-35, slag of silicocalcium production 50-52, magnesite 11-15, quartz sand 3-5. At the same time slag of carbonaceous ferrochrome production contains the following components, wt %: silicon oxide 30-35, calcium oxide 4-6, aluminium oxide 20-30, magnesium oxide 30-35, and slag of silicocalcium production contains the following components, wt %: silicon oxide - 30-35, calcium oxide - 63-68, aluminium oxide - 5-10, magnesium oxide - 0-1, calcium fluoride - 2-10.
EFFECT: invention makes it possible to avoid expensive technologies for manufacturing of each components within a flux.
SUBSTANCE: proposed method comprises bismuth fusing. Note here that bismuth is fused with sodium hydroxide flux. Then, metallic sodium or bismuth-sodium addition alloy is introduced into bismuth melt. Amount of sodium or sodium in said bismuth-sodium addition alloy makes 0.1-0.3 wt %. Then, said melt is mixed at 340-360°C. Thereafter, melt cleaned of polonium is settled to remove alkaline fusion cake. Note that said melt is mixed at 340-360°C for 2 to 3 hours while settling is performed for, at least, one hour. Thereafter, melt cleaned of polonium is additionally treated by the mix of sodium hydroxide and sodium nitrate.
EFFECT: higher yield and efficiency.
4 cl, 10 ex
SUBSTANCE: according to the proposed method, aluminium-silicon alloy is first subject to modification by supplying the mixture consisting of chloric and fluoric salts to the molten metal heel; then, after cleaning of molten metal heel from products of their interaction with liquid alloy, which is treated with direct current.
EFFECT: invention allows considerably increasing the duration of action of modification effect for maintaining high mechanical properties of castings.
2 cl, 1 dwg, 1 tbl
SUBSTANCE: procedure for chemical purification of chloride-magnesium melt from impurities consists on pouring magnesium chloride into tanks, in dilution it with electrolyte of magnesium electrolyser, in loading chemical reagent, in mixing and in settling. As chemical reagent there is used calcium oxide at amount of 0.1-1 % of weight of mixture of melted magnesium chloride and electrolyte. Upon settling a clarified part is withdrawn and directed into electrolyser, while a bottom part is directed for utilisation of magnesium chloride.
EFFECT: reduced expenditures for purification.
6 cl, 1 ex
SUBSTANCE: empty ladle is heated to temperature of its lining 800-1600°C. Crushed aluminium and dry salt chosen from a group: barium, potassium, sodium salt or their mixture or their mixture with additives of powders of cryolite and silicate-block are loaded into the ladle. The ladle is subjected to vibration wherein aluminium and salts are mixed and melted, whereupon melted steel is poured into the ladle at maintaining vibration of the ladle. The ladle filled with liquid materials is vibrated during 10-300 seconds. Vibration frequency is increased 1.5-3 times intensifying steel de-oxidation with liquid aluminium and removal of aluminium oxides and non-metallic inclusion from steel as vibration frequency is growing. Further vibration is stopped, slag is removed and de-oxidised and purified from non-metal inclusions metal is teemed in a mould.
EFFECT: raised efficiency of de-oxidation, reduced losses of temperature and fluidity of metal, reduced rejects of produced ingots.
SUBSTANCE: invention refers to melted salts for purification of magnesium alloys with efficient removal of impurities and minimal losses of strontium from melt of strontium containing melted magnesium alloy. This melted salt corresponds to double melted salt LiCl-KCl, triple melted salt LiCl-KCl-NaCl or double or triple melted salt containing 20% or less of MgCl2 or CaCl2 from general weight of melted salt. Melted salt in working process can contain 10 wt % or less of impurities.
EFFECT: increased efficiency at production of ingot of strontium containing magnesium alloy.
3 cl, 4 ex, 1 tbl
SUBSTANCE: procedure consists in charging solid salt into heated tank, in pouring melt water-free carnallite on surface of solid salt, in mixing and heating produced mixture, in charging calcium fluoride and in extracting produced flux from tank. As solid salt there is used sodium bromide. Produced melted mixture is stirred with dry compressed air to complete dissolution of sodium bromide. Upon calcium fluoride loading produced melted mixture is again stirred with dry compressed air. Produced flux contains the flowing composition of components, wt %: 20-40 MgCl2, 10-30 NaBr, 2-10 CaF2, 30-35 KCl, 5-10 NaCl.
EFFECT: production of flux of uniform structure due to usage of solid sodium bromide with lower melting temperature instead of barium chloride.
FIELD: machine building.
SUBSTANCE: furnace consists of lined jacket with electrodes, and of bell installed inside with charge chamber and central vertical channel, with vertical webbing, overflow channels and bottom between two of ribs and two branches with removable funnels. An orifice of diameter bigger, than diameter of a charging branch and of cross section less, than cross section of the overflow channels in vertical ribs near the charging branch is made in the bottom under the charging branch. The removable charging funnel is ended with a cup-like guide of flow at depth of 0.1-0.5 of height of the bell from its top. Also diameter of the guide is 30-80 mm bigger, than diameter of the end of the charging funnel. Working electrolyte of electrolytic cells is used as heating salt.
EFFECT: simplified furnace maintenance, reduced losses of magnesium and elimination of harmful components from composition of heating salt.
5 cl, 2 dwg, 1 tbl
SUBSTANCE: procedure for refining aluminium alloys consists in treating melt at temperature 750-760°C with briquette flux containing organic or non-organic binding, chlorides, fluorides and refractory fillers in form of dispersed particles of high melting aluminium and silicon oxides. When organic binding is used, flux has the following chemical composition, wt %: KCl 2.0-10.0; NaCl 2.0-10.0; organic binding 2.0-3.0; SiO2 or Al2O3·2SiO2 - the rest. 20-30 % water solution of salt constituent of flux is used as non-organic binding.
EFFECT: increased refining property and efficiency of process.
2 cl, 1 tbl, 7 ex
SUBSTANCE: method includes double-stage treatment of gases first in cyclones with return of trapped dust for melting process, then in metal fabric filters with dust production. After treatment of gases dust is removed from filters and further processed. At the same time dust after extraction from a metal fabric filter is loaded into a reservoir, binder is supplied, mixed to produce a paste-like mixture. Then the mixture is granulated to produce granules, which are dried and sent for further processing by chlorination. Using a suspension of sludge of carnallite chlorators makes it possible to additionally recycle wastes of magnesium production.
EFFECT: recycling of wastes in the form of granules in a titanium chlorator, reduced losses of valuable components, reduced pollution of environment.
5 cl, 2 ex
SUBSTANCE: method involves dipping of wastes into acid electrolyte, connection to a positive pole of an electric current source and performance of electrolysis with conversion of cobalt to a solution and tungsten to slurry. Electrolysis is performed using direct current. As electrolyte there used is 5-15% of sulphuric acid solution containing 2% of a reducing agent. As a result, tungsten is obtained in slurry in the form of tungsten carbide powder.
EFFECT: excluding formation of tungstic acid in slurry.
1 dwg, 1 ex
SUBSTANCE: invention refers to metallurgy of precious metals, and namely to processing of slurries and concentrates containing elementary silicon, carbon and platinum. Similar slurries are formed namely at dilution of platinum-containing cast-iron in sulphuric acid. Slurries are mixed with sodium carbonate at consumption of 120-150% of the weight of silicon and carbon in initial material and sintered at the temperature of 500-650°C during 1-2 hours. Sintered material is leached in water so that insoluble residue containing precious metals and being a concentrate of precious metals is obtained.
EFFECT: simpler technology and higher quality of concentrate.
1 tbl, 1 ex
SUBSTANCE: proposed method comprises stock pelletizing and two-stage high-temperature calcination. said stock represents red mud while high-temperature calcination is divided into oxidative calcination and reducing calcination processes. Note here that oxidative calcination is carried out at 1000-1150°C in airflow. Note also that reducing calcination is performed at 1100-1200°C using coke as reducer in amount of 45-55 wt % of the weight of pellets.
EFFECT: reduced content of sulfur, phosphorus and alkaline compounds, higher strength.
2 cl, 2 dwg
SUBSTANCE: method of lead extraction from lead wastes containing one or more of Pb, PbO, PbO2 and PbSO4 includes treatment with aqueous solution of citric acid with production of lead citrate. Then lead citrate is extracted from the aqeuous solution, and the extracted lead citrate is converted into Pb and/or PbO. The method for processing of lead accumulator batteries, containing or more of Pb, PbO, PbO2 and PbSO4 includes mixing of a paste of lead plates of accumulator batteries with the aqueous solution of citric acid for production of lead citrate. Then lead citrate is extracted from the aqueous solution, and lead citrate is converted into lead and/or lead oxide. Further Pb and/or PbO are included into a plate of an accumulator battery.
EFFECT: simplified process and its improved cost-effectiveness.
17 cl, 7 dwg, 8 tbl, 1 ex
SUBSTANCE: method for processing of copper-based electronic scrap containing noble metals, consists in the fact that the electronic scrap is exposed to oxidising melting to produce an alloy with copper content of 55-85 wt %. The produced alloy is exposed to dissolution by means of electrochemical dissolution in a sulphate copper solution at voltage of 0.8-1.5 V on electrodes with production of sludge containing gold and silver, and an alloy on the cathode, containing copper and palladium. This alloy is exposed to electrochemical dissolution in the copper sulphate solution at voltage of 0.3-0.5 V on electrodes to produce copper on the cathode and sludge containing palladium. At the same time the produced sludges without mixing are leached with sulfuric acid.
EFFECT: higher extent of copper and noble metals extraction from copper-based electronic scrap.
SUBSTANCE: method involves crushing chemical cells, leaching, magnetic separation and electrolysis. The cells are crushed and leached with water in an atmosphere of carbon dioxide gas without access to oxygen. Light fractions are then removed from the scrap by floatation. Filtration is then carried out. The filtrate is treated with sorbents. After filtration, the scrap is washed with water, dried and fragments of ferrous and nonferrous metals are removed by electromagnetic separation, and then leached with sulphuric acid solution. Sulphuric acid pulp is filtered through a filter with an inert material, a filter with a coal medium and a filter with a cation-exchange medium. Ions of row d and row p metals sorbed by a cation-exchange resin are selectively desorbed with sulphuric acid solutions. Solutions containing ions of row d metals are subjected to electrolysis, and solutions containing ions of row p metals are neutralised to pH 3-4 and treated with clay mineral sorbents. The precipitate after sulphuric acid leaching is leached with nitric acid solution; the undissolved manganese dioxide precipitate is removed and the filtrate is neutralised and acidified to pH 3. The precipitate is filtered off. The filtrate containing mercury ions is subjected to cathode reduction and the precipitate containing lead and silver chlorides is dissolved in nitric acid and subjected to cathode reduction in an electrolysis cell with separate deposition of metals on electrodes.
EFFECT: environmental safety of recycling any type of spent chemical cells.
SUBSTANCE: proposed composition comprises 3.0-5.0 wt % of dichlorisocyanuric acid soda as halogen-bearing compound, 0.5-1.5 wt % of thiourea as complexing agent and water making the rest.
EFFECT: higher efficiency of removal mercury from soil, reduced aggressiveness of used substances relative to rooms interior, instruments and equipment.
SUBSTANCE: proposed method comprises anodic oxidation of melt in acid electrolyte at application of electric current. Note here that said anodic oxidation is carried out in acid electrolyte containing 150 g/l of H2SO4+50 g/l HCl. Applied direct electric current features density of 250-300 mA/cm2. Application of said current is conducted at 20-40°C.
EFFECT: notable increase in anodic oxidation rate.
3 tbl, 2 ex
SUBSTANCE: proposed method comprises thermal treatment of residues in air whereat temperature is increased to, at least 500°C at the rate of 150 °/h and curing at said temperature for, at least, two hours. Treated residues are mixed with aluminium powder resulted from grinding aluminium chips and are subjected to aluminothermy with subsequent separation of formed alloy and slag. Aluminothermy is conducted in tight reactor with continuous discharge of gaseous and sublimate reaction products. Note here that aluminium powder and thermally treated residues are taken at the ratio of 1: 6.5-7.0).
EFFECT: higher efficience of processing galvanic process copper bearing residues, method simplifying and higher ecological safety.
3 dwg, 2 tbl, 2 ex
SUBSTANCE: separation method of copper-nickel nis matte containing copper, cobalt and iron into copper and nickel concentrates involves its treatment with melt of alkali metal chloride for dilution of copper sulphide in it. Then, nickel sulphide is separated from copper sulphide by draining chloride melt with copper sulphide diluted in it and recovery of melt of alkali metal chloride. Nis matte containing up to 35 wt % of copper is subject to treatment with chloride melt and treatment is performed with sodium chloride melt at the temperature of 950-900°C. Nickel sulphide that remains after separation from copper sulphide is treated again with sodium chloride melt at the temperature of 900°C. Crystals of copper sulphide are extracted from chloride melt with diluted copper sulphide and sodium chloride melt is recovered by cooling of chloride melt from 900°C to 750°C by supplying nitrogen to its surface.
EFFECT: simpler separation technology of copper-nickel nis matte containing considerable quantities of copper; reduction of power and material costs.
3 cl, 2 tbl, 3 ex