RU2384634C1 - Method of gold-bearing cyanic solutions cleaning - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: invention relates to hydrometallurgical method of cleaning of gold-bearing cyanic solutions after desorption of gold from nonferrous metals before electric precipitation of gold. Method corresponds to that it is implemented treatment of solution by oxidising agent for destruction of cyanic complex of nonferrous metals and sedimentation of its compositions. In the capacity of oxidising agent it is used hydrogen peroxide with consumption not less than 4 l/m3. Treatment is implemented during 3-5 min at temperature 60 - 100C. ^ EFFECT: purification effectiveness increase of solutions and receiving of concentrate of nonferrous metals for its further treatment. ^ 7 dwg, 7 tbl

Description

The invention relates to hydrometallurgical methods for cleaning solutions after gold desorption.

As a result of the process of desorption of gold from sorbents, a saturated solution of gold and non-ferrous metals is obtained; upon further electrolytic deposition of gold, non-ferrous metals also pass into the cathode metal, polluting it. To obtain a purer metal, the solution after desorption is proposed to be treated with an oxidizing agent, as a result of which the poorly soluble or insoluble non-ferrous hydroxides are precipitated.

In the literature, there is insufficient information on the methods for purifying solutions before electrolytic gold production.

Currently, activated coke coal is widely used in the sorption process for the extraction of gold from the liquid phase of pulps. This sorbent is not particularly selective for impurity metals; desorption of gold from coal produces commodity electrolytes containing impurity metals (M.A. Meretukov. Active carbons and the cyanide process. - M.: Ore and Metals Publishing House, 2007. - 288 p.)

The disadvantage of this method is that during the process of electrolytic production of gold, impurities are deposited in the cathode deposit and reduce its quality. To improve the quality, additional operations are required, in particular, cleaning the solution after desorption of non-ferrous metals.

The objective of the invention is the purification of the solution after desorption from non-ferrous metals, which during the subsequent electrolysis process are deposited together with gold in a cathode deposit.

The problem is solved in that in the method of purification of a gold-containing cyanide solution obtained after desorption of gold from a sorbent from non-ferrous metals before the deposition of gold according to the invention, the solution is treated with an oxidizing agent to break down non-ferrous cyanide complexes and precipitate their compounds, and peroxide is used as an oxidizing agent hydrogen, with a flow rate of at least 4 l / m ³ , and the treatment is carried out for 3-5 minutes at a temperature of 60-100 ° C.

When hydrogen peroxide is introduced into the solution, non-ferrous metal cyanide complexes break down and precipitate in the form of insoluble compounds - hydroxides, while the gold cyanide complex remains in solution, due to greater stability. When filtering the precipitate is separated from the solution, and the solution itself is directed to the allocation of gold.

The technical result is that with the introduction of an oxidizing agent - hydrogen peroxide, the cyanide complexes of copper, nickel and zinc are destroyed and poorly soluble hydroxides are formed, while the gold cyanide complex is not destroyed.

The precipitate obtained is filtered, the precipitate is used as a ready-made concentrate for processing. The solution after filtration is directed to the extraction of gold by electrolytic deposition and then again to the desorption of gold.

The inventive method is illustrated by drawings.

Figure 1 - the dependence of the nickel content in the electrolyte on the duration of the experiment at different costs of hydrogen peroxide.

Figure 2 - dependence of the copper content in the electrolyte on the duration of the experiment at various costs of hydrogen peroxide.

Figure 3 - the dependence of the zinc content in the electrolyte on the duration of the experiment at different costs of hydrogen peroxide.

Figure 4 - dependence of the gold content in the electrolyte on the duration of the experiment at various costs of hydrogen peroxide.

Figure 5 - dependence of the nickel content in the electrolyte on the duration of the experiment at various temperatures.

Figure 6 - dependence of the copper content in the electrolyte on the duration of the experiment at various temperatures.

Figure 7 - dependence of the zinc content in the electrolyte on the duration of the experiment at various temperatures.

The inventive method is as follows.

To determine the possibility of precipitation of non-ferrous metal compounds, experiments were carried out on the treatment of cyanide non-ferrous metal complexes with an oxidizing agent to form insoluble compounds - hydroxides. Precipitation of cyanide complexes of non-ferrous metals in the form of hydroxides occurred and their separation from the solution by filtration. Hydrogen peroxide was used as an oxidizing agent.

Experiments were conducted to determine the optimal consumption of the oxidizing reagent. The electrolyte solution was heated to 80 ° C, after which hydrogen peroxide was added to it (4, 5, 6, 8 l / m ³ ). The formation of sediment was monitored visually. Used 30% peroxide.

Table 1 The change in the content of elements in the electrolyte at a peroxide consumption of 4 l / m ³ Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66.6 139.4 22 4.08 3 67.2 108.9 18.1 3.67 5 66 99.1 17.22 3.52 fifteen 66.7 84,4 15,2 3.35 thirty 66.8 80.7 14,4 3.17

table 2 The change in the content of elements in the electrolyte at a peroxide consumption of 5 l / m ³ Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66.5 139 36.3 4.13 3 67.1 91.7 22 3.28 5 66.9 66.7 17.8 2.76 fifteen 66.7 55,2 16 2,53 thirty 66.1 48.6 15.8 2,36 Table 3 The change in the content of elements in the electrolyte at a peroxide consumption of 6 l / m ³ Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66,4 127 33.3 4.05 3 66.9 56.2 16 2.98 5 67.1 36.5 13.5 2.42 fifteen 66.6 29.2 13 2,3 thirty 66.1 25.1 12,2 2.18 Table 4 The change in the content of elements in the electrolyte at a peroxide consumption of 8 l / m ³ Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66.3 82.8 10 3.44 3 67 6.9 5.96 2.15 5 66.5 1.9 4.87 1.94 fifteen 66.9 1.23 4.3 1.95 thirty 66,4 0.91 four 1,66

As can be seen from tables 1-4 and figures 1-3, the content of non-ferrous metals in the electrolyte solution decreases with increasing consumption of hydrogen peroxide. At a peroxide consumption of 8 l / m ^3, the nickel content is reduced by 99%, copper - by 90%, zinc - by 60-65%. In this case, the concentration of gold in the solution remains unchanged throughout the experiment (figure 4).

Also, experiments were carried out on the deposition of nickel at an optimal peroxide consumption of 8 l / m ³ at various temperatures - 60, 80, 100 ° C (tables 5, 6, 7).

Table 5 The change in the content of elements in the electrolyte at a temperature of 60 ° C Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66.3 177.9 37,2 3.96 3 66.5 183 29.7 2.95 5 67.3 143.2 24.5 2,39 fifteen 67.6 31,4 13,4 1.9 thirty 65.6 26.5 eleven 1.85 Table 6 The change in the content of elements in the electrolyte at a temperature of 80 ° C Content, mg / L Processing time, min Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66.3 82.8 10 3.44 3 67 6.9 5.96 2.15 5 66.5 1.9 4.87 1.94 fifteen 66.9 1.23 4.3 1.95 thirty 66,4 0.91 four 1,66

Table 7 The change in the content of elements in the electrolyte at a temperature of 100 ° C Processing time, min Content, mg / L Au Ni Cu Zn 0 65.9 166.85 42.8 4,52 one 66 1.84 9.5 2,8 3 66,4 1,62 6 2.45 5 67.1 1,6 5.68 2,34 fifteen 66,2 1.35 4.94 1.93 thirty 66.6 0.83 3,5 1.65

With increasing temperature of the experiment, the degree of deposition of non-ferrous metals increases. The maximum removal of nickel, copper and zinc from the electrolyte is achieved at a temperature of 80-100 ° C. The deposition of the main amount of impurities occurs 3-5 minutes after the addition of the oxidizing agent (FIGS. 5-7).

Thus, the optimal parameters of the process of deposition of non-ferrous metals are:

- temperature 60-100 ° C;

- reagent consumption of at least 4 l / m ³ ;

- processing time 3-5 minutes.

The inventive method is as follows.

A gold-containing cyanide solution is pumped into the container after desorption of gold from the sorbent, where hydrogen peroxide is dosed at a rate of at least 4 l / m ³ . Processing is carried out for 3-5 minutes at a temperature of 60-100 ° C. The cyanide complexes of non-ferrous metals are processed, an insoluble precipitate is formed - non-ferrous metal hydroxides, which are separated from the solution on the filter. The purified solution enters the electrolytic separation of gold.

The inventive method allows you to effectively clean salable electrolyte after desorption of gold from the sorbent from impurity metals with hydrogen peroxide, to obtain a non-ferrous metal concentrate suitable for further processing.

Claims (1)

The method of purification of a gold-containing cyanide solution obtained after desorption of gold from a sorbent from non-ferrous metals before the electrodeposition of gold, which consists in the fact that the solution is treated with an oxidizing agent to destroy non-ferrous cyanide complexes and precipitating their compounds, and hydrogen peroxide is used as an oxidizing agent with a consumption of less than 4 l / m ³ and the treatment is carried out for 3-5 minutes at a temperature of 60-100 ° C.

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