RU2052525C1 - Method for separating copper, cobalt and nickel from ammonium-carbonaceous solutions - Google Patents

Abstract

FIELD: nonferrous metallurgy. SUBSTANCE: method involves adding sodium sulfide to basic solution; separating copper sulfide precipitate obtained; subjecting remaining solution to distillation till predetermined ammonia concentration is reached; filtering precipitate of basic cobalt carbonate; obtaining nickel concentrate by providing further distillation. EFFECT: increased efficiency in extracting metals from solutions. 2 tbl

Description

 The invention relates to the field of non-ferrous metallurgy, in particular to methods for the separation of copper, cobalt and nickel from ammonia-carbonate solutions containing these metals in a total concentration of not more than 5-6 g / l.

 A known method of separating copper, cobalt and Nickel from ammonia-carbonate solutions by distillation of ammonia and carbon dioxide. Copper and nickel are almost completely separated from the solution together, and cobalt is 70-75%. Further co-precipitation is carried out with sodium sulfide.

 The disadvantage of this method of obtaining a collective copper-Nickel-cobalt concentrate.

 The purpose of the invention is the production of selective copper, nickel, cobalt concentrates.

 This goal is achieved by the fact that sodium sulfide is introduced into the solution at the beginning of the process before distillation. Copper from the solution is released in the form of sulfide, and nickel and cobalt remain in solution, since nickel and cobalt sulfides have a higher solubility product. Next, the solution is sent to step distillation. Since the process of cobalt (III) reduction into cobalt (II) with sodium sulfide is introduced simultaneously with the process of copper extraction, the ammonia complex of cobalt (II) is formed, which is much less stable than the ammonia complex of nickel, then cobalt is primarily released. Subsequent distillation of ammonia and carbon dioxide leads to the destruction of the ammonia complex of cobalt and the release of cobalt in the precipitate, while nickel still remains in solution. Thus, during distillation, primarily cobalt concentrate is formed, and then nickel.

 The method is as follows.

The reactor with mechanical stirring poured ammonium carbonate solution is heated to a temperature of 60-100 ^{° C,} sodium sulphide is introduced in an amount necessary to restore complete precipitation of cobalt and copper sulphide and recovery of trivalent cobalt and stirred for 15-30 min. Then the nickel-cobalt solution is separated from the copper precipitate by filtration and sent to distillation. The distillation is carried out at 95-105 ^{° C} to a final concentration of ammonia in the solution 5-6 g / l. After filtering the solution and separating the cobalt precipitate, further distillation is carried out to an ammonia concentration of 0.1-0.3 g / l. Nickel concentrate is separated by filtration.

PRI me R. Ammonia-carbonate solution composition, g / l: cobalt 0.84, copper 0.81, nickel 1.5; ammonia 61; CO ₂ 44.7 was loaded into a glass beaker in an amount of 0.5 L, heated to 80 ^° C, the calculated amount of sodium sulfide was introduced and stirred for 30 minutes. The solution is then separated from the residue on the suction filter and subjected to distillation at ¹⁰⁰ ° C to a final ammonia concentration of 5.5 Sec. The solution after filtration the precipitate was subjected to further distillation at ¹⁰⁰ ° C to a final ammonia concentration of 0.2 g / l. Samples of solutions and sediments were analyzed for metal content. The results are presented in table 1.

 As follows from the results, the proposed method allows to obtain selective copper, Nickel and cobalt concentrate.

The precipitation of copper from solution at temperatures less than 60 ^{° C} deteriorates somewhat, while above 100 ^{° C} does not affect the extraction performance. The bulk of the copper released from the solution in the first 10-15 minutes and ends in 25-30 minutes (table 2).

 To obtain selective cobalt concentrate, ammonia distillation should be carried out to its final concentration of 5-6 g / l. At high concentrations, cobalt from the solution is not completely released, and at lower concentrations, nickel begins to be precipitated, which increases the degree of contamination of cobalt sediment. Nickel release is completed at ammonia concentrations in the solution of 0.1-0.3 g / l.

Claims (1)

 METHOD FOR ISOLATING COPPER, COBALT AND NICKEL FROM AMMONIA-CARBONATE SOLUTIONS, including distillation of ammonia and carbon dioxide, characterized in that sodium sulfide is added to the initial solution, the resulting copper sulfide precipitate is separated, the remaining solution is distilled to 5 g of ammonia / l, the resulting precipitate of basic cobalt carbonate is filtered off, then further distillation is carried out to an ammonia concentration of 0.1 - 0.3 g / l and a nickel concentrate is obtained.

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