FI110789B - Purification of impure copper tellurium precipitate comprises totally purifying copper tellurium precipitate on sulfuric acid base, further leaching residue, removing dissolved impurities and cementing tellurium from solution - Google Patents

Abstract

Purification of impure copper tellurium precipitate formed in the electrolytic purification of copper, comprises totally purifying copper tellurium precipitate on a sulfuric acid base; further leaching of the leaching residue to dissolve final copper and tellurium; removing dissolved impurities and cementing tellurium from solution in non-oxidizing conditions. Purification of impure copper tellurium precipitate formed in the electrolytic purification of copper, comprises totally purifying copper tellurium precipitate on a sulfuric acid base, where part of the copper is firstly removed from the precipitate by leaching in dilute sulfuric acid solution; further leaching of the leaching residue in sulfuric acid solution to dissolve the final copper and tellurium; removing impurities, e.g. chlorine and selenium, which have dissolved in the solution and cementing tellurium from solution in non-oxidizing conditions, where the final product is a copper tellurium alloy, of which tellurium content is 80-100% and the standard of purity is sufficient for an initial alloy manufacture used for the manufacture of tellurium copper.

Description

1,110,789

METHOD FOR CLEANING A COPPER TELLURITE AND THE TELLURO COPPER OBTAINED BY THE METHOD

The present invention relates to a process in which the impure copper telluride formed during the electrolytic S purification of copper is purified from the impurities contained therein. Purification takes place all the time on a sulfuric acid base, whereupon the solution returns can be made to the solution cycles of copper electrolysis. At the same time, the tellurium content of the final product can be increased. Pure copper telluride can be used e.g. for copper alloy 10 (tellurium copper).

In the course of electrolytic refining of copper, impurities in the anode copper behave in principle in two ways: impurities which are less noble dissolve and noble ones remain insoluble. Insoluble compounds form the so-called. anode slime.

Tellurium is present in the anode copper mainly as copper compounds. In the electrolysis process, these copper compounds react partially with anodic silver from the anodes to form copper silvellellellium compounds. Telluuriyhdis-. 20 you may also have gold. These compounds do not dissolve in the electrolysis event, but form part of the ariodiolysis.

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The anode slurry from the electrolysis pool is removed at regular intervals and the slurry treated to recover the precious metals therein. Generally, the slurry is initially solubilized with sulfuric acid and oxygen to form metallic copper and copper oxide, followed by leaching of the nickel and copper compounds. These solutions can also be made simultaneously by autoclaving. In the leaching step of copper compounds, the solution provides not only copper and nickel but also

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»» · ;; · 'Handset, silver and selenium.

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The resulting solution is removed by precipitation and cementation of the dissolved selenium, silver and tellurium. Traditionally, selenium and silver are reduced and precipitated with sulfur dioxide and filtered according to the anode slurry. After filtration, the tellurium is cemented from the solution with metallic copper to give an impure copper telluride precipitate. The copper and nickel-containing filtrate is returned to the solution circulations of the copper electrolysis.

The copper tellurium ratio and purity of the copper tellurium precipitate depend on the cementation technique used. Analysis of the impurity copper telluride precipitate 10 may vary as follows: Cu = 40-50%, Te = 20-40%, Se = 1-15% and Ag = 0.1-3%. In addition, the precipitate may contain impurities e.g. chlorine.

According to generally known technology, impure copper telluride is treated with lye leaching, whereby the tellurium therein is solubilized when copper is precipitated as an oxide. The leaching residue can be further dissolved in sulfuric acid and returned to the solution circulations by copper electrolysis. The resulting crude basic tellurium solution is purified of impurities and the tellurium is electrolytically reduced from the solution. The purity of the reduced tellurium is more than 99%. The process requires regeneration of the alkaline solutions, since they cannot be fed as such with naturally-acidic solutions of copper electrolysis. In this way .. the process easily becomes complex and complex.

For certain applications, tellurium may also contain copper. Including copper ;; * copper tellurium used for alloying traditionally contains about 80% tellurium and • ·> · 25 20% copper. In this case, purification of the impure copper telluride to electrolytically pure tellurium is not meaningful.

According to the present invention, the impure copper telluride can be purified by a simple process to a pure tellurium containing the desired amount of copper. The operating environment is always on the basis of sulfuric acid, when

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| any solution returns can be taken in the 110789 solution cycles of copper electrolysis. The invention also makes it possible to use the copper arsenide precipitate formed during solution purification of copper electrolysis in the tellurium cementation after leaching of the anode slurry. The invention also relates to tellurium copper obtained as a product of the process. The essential features of the invention will be apparent from the appended claims.

In the process of the invention, the impure copper telluride precipitate is initially dissolved in dilute sulfuric acid solution by means of air or oxygen. Hereby, some of the copper in the precipitate is dissolved without the precipitate tellurium slipping 10. The resulting copper sulfate solution is returned to the solution circulations of the copper electrolysis. The leaching residue is further dissolved in sulfuric acid using oxygen or hydrogen peroxide as an oxidant, whereby the tellurium of the precipitate is also dissolved.

The resulting tellurium solution mainly contains selenium and 15 chlorine as harmful impurities. Selenium can be precipitated from solution with sulfur dioxide at a temperature below 40 ° C. Chlorine can be precipitated as chloride with a silver sulfate solution which is further regenerated to silver sulfate by conventional techniques such as hydrazine reduction and sulfuric acid leaching. Another preferred way to remove chlorine is to precipitate it at a temperature of 20-100 ° C, preferably 20-40 ° C, with metallic copper.

I I | * · 'I *' · 'After solution purification, I »* · tellurium is cemented from pure copper tellurium solution with pure copper grit or powder. * * ;; And oxidation prevention in the cementation reactor. The solution can be recycled to the upstream leaching step. From the cemented pure cupitelluride, excess copper is dissolved with sulfuric acid with oxygen. The final product is pure tellurium copper with an adjustable alloy ratio.

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An alternative method of cementation is two-stage cementation. In the first step of the mentification, only part of the tellurium and copper-containing solution is cemented with the copper telluride precipitate> 4,110,789. In the second cementation step, the tellurium cementation is completed using metal copper as the cementing agent. After the first stage cementation, the precipitate contains more than 80% tellurium and less than 20% copper. After drying, the precipitate can be used as a raw material for the preparation of a mixture containing 80% tellurium and 20% copper. The drying of the precipitate must be done in such a way that the precipitate does not oxidize during the drying phase. The principle flow diagram of the process is attached.

The invention is further illustrated by the accompanying drawings and examples, in which Figure 1 shows a flow diagram according to Example 1, and Figure 2 shows a flow diagram according to Example 2.

Example 1.

The starting material used was 10 kg of impure copper telluride precipitate obtained from production scale tellurium cementation. The cementation was done with copper grit. The precipitate was analyzed as follows: Cu = 55.2%, Te = 37.6%, Se = 2.8% and Cl = 2.1%.

· The precipitate was dissolved at 100 ° C with oxygen in a solution of sulfur; ** 20 acid content was 200 g / l. After leaching, the precipitate weighed 4.99 kg and analyzed as follows: Cu = 15.0%, Te = 75.3%, Se = 5.4% and Cl = 0.8%. Analysis of the filtered solution was Cu = 94 g / l, Te = 0.1 g / l, Se <5 mg / l, Cl = t 3.5 g / l and H2SC> 4 = 50 g / l and the filtrate volume was 50 dm3.

• ♦, ···. Next, the precipitate was dissolved in sulfuric acid solution at 100 ° C. · *. The H2SO4 concentration was 300 g / l. At the beginning of the dissolution, oxygen was used as the oxidizing agent and in the final stage hydrogen peroxide was used at 50 ° C. The dissolution time was 15 hours. Prior to filtration, selenium was further precipitated with a solution of sulfur dioxide gas at a temperature of 3838 ° C. Analysis of the resulting solution was Cu =. 11.8 g / l, Te = 59.4 g / l, Se = 80 mg / l, CM310 mg / l and H2SO4 = 295 g / l and the volume of the solution was 63 dm3. The weight of the leaching residue was 400 g (kp = dry weight).

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Analysis of the leaching residue was Cu = 0.5%, Te = 2.5%, Se = 76.8% and Cl = 0.2%.

To remove chloride from the solution, 630 g of copper powder were added to the charge and the 5 charges were stirred at 28 ° C for 5 hours. Air was prevented from entering the solution. After chloride precipitation, the solution was analyzed for Cu = 16.0 g / L, Te = 53.8 g / L, Se = 40 mg / L and Cl = 108 mg / L.

After removal of chloride from the solution, tellurium was cemented with copper powder 10 (5600 g) at 100 ° C to give 4890 g of pure copper telluride precipitate. Analysis of the solution after tellurium cementation was Cu = 73 g / l, Te = 8.0 g / l and H 2 SO 4 = 195 g / l. This solution can further be used for leaching crude copper telluride.

.i .: 15 The precipitate was further processed in a 10 dm3 reactor. In the reactor, the precipitate was treated with a sulfuric acid solution containing 300 g H2SO4 / L at 100 ° C. Oxygen was used as the oxidant at a dissolution time of 5 '' hours. After treatment, the solution was analyzed for Cu = 78 g / l, Te = 0.1 g / l and H 2 SO 4 = 148 g / l. Also, this solution can be utilized in the leaching step of the impure copper-20 condenser. Analysis of the purified tellurium precipitate was Te = 81%, Cu = 18%, Se = 0.1%, Cl = <0.01% and O 2 = 2.1%. The total content of other impurities was <0.1%. The amount of precipitate was 3970 g (bp).

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The resultant dried tellurium precipitate was thawed in an induction oven. Charcoal was used on the molten surface to remove oxygen. The molten metal was cast at 480 ° C. from one end to a solid copper tube and a casting in a tube »» • It was used as a premix in the smelting of tellurium copper ingot. The analysis of the mixture poured into the tube was Te = 81%, Cu = 18%, Se = 0.08%, Cl <0.01% and O 2 = 60 ppm.

30 110789

Example 2.

The crude copper tellurium precipitate was prepared by cementing the tellurium solution with tellurium copper arsenide precipitate. The copper arsenide precipitate was obtained from the copper removal electrolysis of the solution purification process of copper. Analysis of Tellurium-5 solution was Cu = 44.4 g / L, Te = 12.0 g / L, Cl = 41 mg / L and H 2 SO 4 = 213 g / L. The copper arsenide used in the cementation was Cu = 65.3%, As = 24.7%, Bi = 1.7% and Sb = 1.1%. Cementation was carried out in a 25 liter reactor and at 100 ° C. A total of 592 g (kp) of copper arsenide precipitate was added in three batches and the end point of cementation was monitored with 10 redox sensors. The cementation time was 2 hours 10 minutes. After cementation, the solution analysis was Cu = 49.6 g / L, Te <10 mg / L, As = 6.6 g / L, Sb = 244 mg / L, Bi = 394 mg / L, Cl = 24 mg / L. and H2SO4 = 215 g / l.

The resulting copper telluride precipitate was analyzed for: Cu = 40.4%, Te = 59.2%, As = 15 0.33%, Sb = 0.05%, Bi = 0.03% and Cl = 0.07%. 511 g (kp) of copper telluride precipitate was initially dissolved in sulfuric acid solution (H 2 SO 4 = 150 g / l) at 98 ° C using oxygen as the oxidant. The reactor was equipped with a gls mixer. After a 4 hour dissolution time, the solution analysis was Cu = 26 g / L, Te = 14 mg / L, As = 443 mg / L, Sb = 21 mg / L, Bi = 17 mg / L and Cl = 30 mg / L. Thereafter, the * 20 dissolution was stopped. Based on the solution and the initial copper precipitated, 63.6% was dissolved at this point.

. The precipitation of the precipitate was continued in a more concentrated sulfuric acid solution (H2SO4 = 300 g / l). The temperature of the leaching was 98 ° C and the oxidant was used. 25 still oxygen. The mixer was a gls mixer and the solution volume at this stage was 7 liters. After 13 hours of dissolution, the solution analysis was as follows:. Cu = 10.9 g / L, Te = 41 g / L, As = 10 mg / L, Sb = 6 mg / L, Bi = 3 mg / L and Cl = 48 mg / L.

I i · ·, · · ·. At this point, the soluble yield of tellurium became 94.9%.

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The solution was de-chlorinated with silver sulfate solution. No other solution purification was needed in this case. The solution had a chlorine content of <10 mg / l after precipitation.

Next, the solution was subjected to a two-step cementation, in which the solution is cemented in a first step with a cementation slurry from the second step. The first stage cementation precipitate is the end product of the process.

Since the actual second-stage cementation precipitate was not initially available, the precipitate was prepared by cementing the tellurium-containing solution with tellurium copper powder. This tellurium precipitate was then used in the first step. The temperature of the cementation was 80 ° C and the effect of air oxygen on precipitation was prevented. Cementation was not completed with respect to tellurium. After the first Semen step, the analysis of the solution was Cu = 36 g / l, Te = 14.7 g / l. Analysis of the resulting 15 precipitates was Te = 83%, Cu = 16%, O2 = 0.9% and other impurities less than 0.05%.

In the second step, the cementation conditions were the same as in the first step, and 420 g of fine copper powder was fed to the reactor. Here: In 20 steps, the final solution of the solution was cemented. After cementation, the solution was analyzed for Cu = 63 g / l and Te <0.1 g / l. The volume of the filtrate was 7 dm 3. The resulting · · tellurium resin can still be used in the first stage of tellurium cementation.

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Claims (17)

A process for the purification of an impure copper telluride precipitate formed by electrolytic copper purification, characterized in that the copper telluride precipitate is completely purified on a sulfuric acid base; chlorine and selenium, ίο, and tellurium are cemented from the solution under non-oxidizing conditions to give the final product a copper tellurium compound having a tellurium content of 80-100% and a purity sufficient to make the premix for the production of tellurium copper. 2. Förfarande enligt patentkrav 1, kännetecknat av att lakningen av en Oren coppartellurfällning utförs i peg första steg en en av copuparn i fällningen lacquer med hjälp av syre eller luft vid en Temperature av 90-100 ° C i en svavelsyrals. en svavelsyrahalt av 100 - 400 g / l och i andra ίο steg lakningsaterstoden frän första steget varnish med hjälp av syre eller luft vid en tempur av 90-100 ° C i en svavelsyralösning med en svavelsyrahalt av 300 - 600 g / l. Process according to Claim 1, characterized in that the leaching of the impure copper telluride precipitate takes place in a two-step process, in which a part of the copper is precipitated by oxygen or air at 90-100 ° C in a sulfuric acid solution of 100-400 g / l. • · · The 20-stage leaching residue is dissolved in oxygen or air at a temperature of 90 ° C to 100 ° C in a sulfuric acid solution containing 300 to 600 g / l sulfuric acid. * «· * • 3. Förfarande enligt patentkrav 2, kangnetecknat av att h ^ SCVhalten i första 15 sticks at 100-200 g / l and H2SO4-halten sticks at 250-350 g / l. : '. · 4. Förfarande enligt patentkrav 1, kännetecknat av att slutlakningen av: lakningsaterstoden frän första steget utförs med wetter peroxide at 20 - 80 ° C i svavelsyralösning med en svavelsyrahalt av 20 200-600 g / l. The process according to claim 2, characterized in that the hbSCV content of the first stage is 100-200 g / l and the hhSO r content of the second stage 25 is 250-350 g / l. A process according to claim 1, characterized in that the final leaching of the first stage leaching residue is carried out with hydrogen peroxide or oxygen at a temperature of 20 to 80 ° C in a sulfuric acid solution; 30 with a sulfuric acid content of 200-600 g / l. 9 110789 5. Förfarande enligt patentkrav 4, a rotating device for sliding the lacquering of the lacquer in the styrofoam in the range of 20 to 80 ° C and weighing 25 250 - 350 g / l. Process according to Claim 4, characterized in that the final leaching of the leaching residue from the first stage is carried out with hydrogen peroxide or oxygen at a temperature of 20 to 80 ° C in a sulfuric acid solution having a sulfuric acid content of 250 to 350 g / l. 5 6. Förfarande enligt patentkrav 1, kännetecknat av att Selen som ingär i lösningen som förorening falls et medavavioxide vid en tempur: understigande 40 ° C. I i 30 110789 Process according to Claim 1, characterized in that the selenium impurities in the solution are precipitated with sulfur dioxide at a temperature below 40 ° C. Method according to claim 1, characterized in that the precipitation of the chlorine impure in the solution is carried out at a temperature of 20 to 100 ° C with the aid of metallic copper. 7. Förfarande enligt patentkrav 1, kännetecknat av att klor som Ingar i lösningen som förorening falls ut mediske in the temperature range of 20-100 ° C. 5 8. Förfarande enligt patentkrav 7, kännetecknat av att klor som Ingar i lösningen som förorening falls ut vid en temperature between 20 - 40 ° C with a metallic bucket. Process according to Claim 7, characterized in that the precipitation of the chlorine impure in solution is carried out at a temperature of 20 to 40 ° C by means of metallic copper. 9. Förfarande enligt patentkrav 1, kännetecknat av att den Rena ßο copartellurföreningens blandningsförhallande franken genus att urbav därav med hjälp av syre vid en tempur av 90-100 ° C i svavelsyralösning med en svavelsyrahalt av 200 - 600 g. Process according to Claim 1, characterized in that the mixture ratio of the pure copper tellurium compound is changed by dissolving copper therein with oxygen at a temperature of 90-100 ° C in a sulfuric acid solution having a sulfuric acid content of 200-600 g / l. The process according to claim 9, characterized in that the ratio of the pure copper tellurium compound is altered by dissolving 25 copper therein with oxygen at 90-100 ° C in a sulfuric acid solution having a sulfuric acid content of 250-350 g / l. The process according to claim 1, characterized in that the * * I ratio of pure copper tellurium compound is adjusted by two-stage cementation of tellurium: 30 and by use of a second-stage cementation precipitate in the first stage. 10 110789 10. Förfarande enligt patentkrav 9, kännetecknat av att den Rena 15 copartellurföreningens blandningsförhallande genome att uracaka. · The bucket därav med hjälp av syre vid en tempur av 90-100 ° C. · · Svavelsyralösning med en svavelsyrahalt av 250 - 350 g / l. 11. Förfarande enligt patentkrav I, kännetecknat av att den Rena '20 copartellurföreningens blandningsförhallande regleras genome att utföra;' 'Cementeringen av Tellur i tva steg och använda cementeringsfällningen fran andra steget i första steget. 12. Förfarande enligt patentkrav 1, kännetecknat av att den cementerade 25 tellurkopparfällningen pricked under icke-oxiderande förhäilanden och gjuts', t account en slutprodukt. .; ·· 13. Förfarande enligt nägot av de föregaende patentkraven, kännetecknat. V av picture slutproductens selenhalt uppgar högst account 0.1%. y *. 30 13 Π0789 Process according to Claim 1, characterized in that the cemented tellurium copper precipitate is dried under non-oxidizing conditions and cast into the final product. 5 Process according to one of the preceding claims, characterized in that the final product has a selenium content of up to 0.1%. 14. Förfarande enligt nagot av de föregäende patentkraven, kännetecknat av att slutproduktens klorhalt uppgär högst account 0.01%. Process according to any one of the preceding claims, characterized in that the final product has a chlorine content of up to 0.01%. 15. Tellurkoppar som har framställts av en Oren koppartellurfällning som 5 bildas vid electrolytisk raffinering av koppar, kanknetecknad av att tellurkoppam har framställts av svavelsyrabasis och dess tellurhalt uppgär account 80-100%, colors resten är koppar och naturliga föror. 15. Tellurium copper made from an impure copper brick precipitate from the electrolytic purification of copper, characterized in that the tellurium copper is based on a sulfuric acid and has a tellurium content of 80-100% with the remainder being copper and natural impurities. 16. Tellurkoppar enligt patentkrav 14, tilankecknad av att tellurkopparns already selenhalt uppgär högst account 0.1%. Tellurium copper according to claim 14, characterized in that; . the selenium content of tellurium copper is not more than 0,1%. Tellurium copper according to claim 14, characterized in that the chlorine content of the tellurium copper is at most 0.01%. 25 1. Förfarande för rening av en Oren copartelluridfällning som image vid electrolytisk raffinering av koppar, kännetecknat av att copartellurid- · fällningen renas helt pä svavelsyrabasis, color fällningen först befrias fran en del av den koppar som ingär dääll genom att laka . · Svavelsyralösning, lakningsaterstoden lacquer vidare i en svavelsyralösning för 30 urlakning av restkoppam och telluren, den erhällna lösningen får från däri upplösta föroreningarna sasom klor och selen, och Tellur cementeras förenförenförenfuren en tellurhalt av 80 - 100% och vars renhetsgrad är tillräcklig för framställning av en förblandning avsedd att avvändas vid framställningen av tellurkoppar. 5 17. Tellurkoppar enligt patentkrav 14, Kanknetecknad av att tellurkopparns chlorhalt uppgär högst account 0.01%. 15