Electrodeposition method for analyzing pregnant solution through resin ore pulp method

Abstract

The invention provides an electrodeposition method for analyzing pregnant solution through a resin ore pulp method, and belongs to the technical field of hydrometallurgy. Reversely connecting the cathode and the anode of the electrolytic cell, and temporarily using an anode plate as a cathode; electrolyzing under low current density to form a compact gold plating layer on the surface of the anode; and then the height of the liquid level in the electrolytic cell is reduced, and a normal analysis electrolysis process is carried out under the conditions of conventional current density and cell voltage until recovery of gold in the gold-loaded resin is completed. According to the method, anode corrosion loss caused by chloride ions in the electrodeposition process can be effectively reduced, and the quality of electrodeposited gold mud is improved. Compared with the existing gold-loaded resin desorption electrolysis process, the method can greatly prolong the service cycle of the stainless steel anode plate and improve the subsequent gold mud smelting and purifying efficiency at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy, and relates to a noble liquid electrodeposition method, in particular to an noble liquid electrodeposition method for analyzing the noble liquid by a resin slurry method. Background Art

[0002] The full-slime cyanidation gold extraction process is a common method for extracting gold from gold ore, and is usually used for ores where gold is evenly distributed in fine or micro-particles. In the case of low sulfide content, less other harmful impurities, poor selectivity of gold-bearing minerals and low gold content in the ore, the full-slime cyanidation gold extraction process is used for gold extraction, with relatively low production costs and more economical.

[0003] In the full-slime cyanidation gold extraction process, the resin slurry method is an important treatment method for extracting gold from the leaching slurry. The resin has a larger specific surface area, and its gold absorption speed, gold absorption capacity and strength are higher than those of activated carbon, and it also has a larger adsorption capacity for silver. Compared with the activated carbon method under the same operating conditions, the resin slurry method has a higher gold recovery rate, and the resin loss is relatively small, which can further reduce production costs.

[0004] When analyzing saturated gold-loaded resin, it is generally first washed in reverse with clean water to remove the slurry particles and impurities attached to the surface; then diluted hydrochloric acid is used to wash to remove the scaling of the resin pores, so as to facilitate the subsequent analysis process. In actual production, the gold-loaded resin analysis solution is usually prepared with ammonium thiocyanate with a concentration of 90~125g / L and sodium hydroxide with a concentration of 8~12g / L, and the analysis temperature is 50~55℃. Both the cathode and anode plates of the electrodeposition are made of stainless steel, and the analysis electrolysis cycle is usually more than 24 hours. However, it was found in production that due to the residue after washing with dilute hydrochloric acid and the purity of ammonium thiocyanate and sodium hydroxide reagents, a certain amount of chloride ions will be contained in the analysis precious solution. During the electrodeposition process, chloride ions discharge on the anode surface to generate chlorine gas, which in turn causes corrosion of the anode stainless steel plate. In severe cases, the service life of the anode plate will be reduced to less than 36h. In addition, a large number of "iron particles" detached from the anode by corrosion and hydroxide precipitates generated by iron ions produced by corrosion will enter the electrolytic gold mud, causing the total gold and silver content of the electrolytic gold mud to be less than 10%, resulting in an increase in the amount of subsequent gold mud smelting slag, an increase in smelting costs, and a decrease in the direct yield of precious metal smelting. In addition, the corroded and detached stainless steel "iron particles" make it difficult to remove the iron impurities in the electrolytic gold mud by conventional pickling processes. Therefore, a new process is urgently needed to solve the problem of electrolysis of precious liquid by the chlorine-containing resin slurry method. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an electrodeposition method for analyzing precious liquid by a resin slurry method, so as to solve the problem of electrolytic anode corrosion caused by chloride ions generated in the analyzed precious liquid and the resulting low efficiency of electrolytic gold mud smelting and purification.

[0006] The technical solution of the present invention is as follows: An electrodeposition method for analyzing precious liquid by resin slurry method, wherein the gold-carrying resin is analyzed by ammonium thiocyanate and sodium hydroxide system, the concentration of ammonium thiocyanate in the analysis solution is 100-120 g / L, the concentration of sodium hydroxide is 9-11 g / L, and the temperature of the analysis solution is 53-57°C, and the steps are as follows: Step 1: Gold plating on the anode surface: Reverse the positive and negative poles of the electrolytic cell, and use the anode plate as the cathode; Step 2: Adjust the liquid level of the electrolytic cell: lower the liquid level of the electrolytic cell; Step 3: Analytical electrolysis.

[0007] Preferably, during the gold plating process on the anode surface in step 1, the anode current density does not exceed 10A / m 2 .

[0008] Preferably, in step 1, the gold plating time on the anode surface is not less than 2 hours.

[0009] Preferably, the chloride ion concentration in the system does not exceed 30 g / L.

[0010] Preferably, when adjusting the liquid level of the electrolytic cell in step 2, the liquid level is lowered by 5% to 10% of the electrode height.

[0011] Compared with the prior art, the present invention has the following beneficial effects: First, the present invention forms a dense gold plating layer on the anode surface by adjusting the cathode and cathode and the electrolysis current density without changing the existing analytical electrolysis equipment, and utilizes the excellent corrosion resistance of gold to effectively avoid the problem of anode corrosion during the electro-deposition process of chlorine-containing analytical precious solution.

[0012] Second, since the gold-loaded resin analysis usually uses an ammonium thiocyanate and sodium hydroxide system, the free cyanide ion content in the analysis solution is extremely low, and it is generally required to control the chloride ion concentration in the analysis precious solution to not exceed 30 g / L. Therefore, the gold on the anode surface will not undergo electrochemical corrosion to generate Au(CN)-4 or AuCl-4 during the electrolysis process, ensuring the stable existence of the gold plating layer on the anode surface. At the same time, during normal analysis electrolysis, corrosion at the connection can be effectively avoided by lowering the liquid level in the tank to control the height. Experiments have shown that when the method of the present invention is used for 24h analysis electrolysis, the weight loss of the anode plate corrosion is less than 0.5%; the degree of corrosion of the anode plate during the electrolysis process is greatly reduced, and the service life is correspondingly extended.

[0013] Third, since the iron-containing precipitate produced by the corrosion of the anode plate during the electrolysis process is very small, the present invention can obtain electrolytic gold mud with higher quality; and no additional iron removal operation is required in the subsequent electrolytic gold mud smelting process, thus greatly improving the gold mud smelting efficiency. DETAILED DESCRIPTION

[0014] The present invention is further described below in conjunction with embodiments and experimental data.

[0015] Embodiment 1 Gold-loaded resin analysis system: The gold-loaded resin is analyzed using an ammonium thiocyanate and sodium hydroxide system. In this embodiment, the gold-loaded resin has a gold content of 1247 g / t. The concentration of ammonium thiocyanate in the analysis solution is 110 g / L, and the concentration of sodium hydroxide is 10 g / L. The temperature of the analysis solution is 55°C. After testing, the chloride ion content in the analysis solution is 4.79 g / L.

[0016] (1) Gold plating on the anode surface: Reverse the positive and negative poles of the electrolytic cell, use the anode plate as the cathode, and adjust the anode current density to 9A / m 2 , electrodeposition time is 3 h.

[0017] (2) Adjusting the liquid level in the electrolytic cell: In this embodiment, the electrode height is 1 m and the liquid level is lowered by 8 cm.

[0018] (3) Analytical electrolysis: Anode current density 30~35 A / m 2 , cell voltage 3~4V, electrolysis time 24h, desorption liquid flow rate 15~18m 3 / h.

[0019] (4) Detection: After analysis, the gold content of the lean resin was 91.14 g / t, the weight loss of the anode plate due to corrosion was 0.20%, the iron content in the electrolytic gold mud was 0.12%, and the total gold and silver content in the electrolytic gold mud exceeded 93.7%.

[0020] Embodiment 2 Gold-loaded resin analysis system: The gold-loaded resin is analyzed using an ammonium thiocyanate and sodium hydroxide system. In this embodiment, the gold content of the gold-loaded resin is 982 g / t. The concentration of ammonium thiocyanate in the analysis solution is 110 g / L, and the concentration of sodium hydroxide is 10 g / L. The temperature of the analysis solution is 55°C. After testing, the chloride ion content in the analysis solution is 6.31 g / L.

[0021] (1) Gold plating on the anode surface: Reverse the positive and negative poles of the electrolytic cell, use the anode plate as the cathode, and adjust the anode current density to 8A / m 2 , electrodeposition time is 3 h.

[0022] (2) Adjusting the liquid level in the electrolytic cell: In this embodiment, the electrode height is 1 m and the liquid level is lowered by 6 cm.

[0023] (3) Analytical electrolysis: same as in Example 1.

[0024] (4) Detection: After analysis, the gold content of the lean resin was 82.08 g / t, the weight loss of the anode plate due to corrosion was 0.14%, the iron content in the electrolytic gold mud was 0.11%, and the total gold and silver content in the electrolytic gold mud exceeded 95.2%.

[0025] Comparative Example 1 The anode current density in step (1) of Example 1 was adjusted to 15 A / m 2 , other operations remain unchanged, test results: the gold-plated layer on the surface of the anode plate fell off, and the anode plate lost 3.4% of its weight due to corrosion.

[0026] Comparative Example 2 The electrodeposition time in step (1) of Example 1 was adjusted to 1.0 h, and other operations remained unchanged. The test results showed that pitting corrosion occurred on the surface of the anode plate, and the anode plate lost 0.8% of its weight due to corrosion.

[0027] Comparative Example 3 Step (2) of Example 1 is omitted, i.e. the liquid level of the electrolytic cell is not adjusted, and other operations remain unchanged. The test results show that the transition joint between the gold-plated layer on the surface of the anode plate and the stainless steel plate is severely corroded, and some of the plates have been broken along the joint, making it impossible to carry out the electrolysis process normally.

Claims

1. An electrodeposition method for analyzing precious liquid by resin slurry method, wherein the gold-carrying resin is analyzed by ammonium thiocyanate and sodium hydroxide system, the concentration of ammonium thiocyanate in the analysis solution is 100-120 g / L, the concentration of sodium hydroxide is 9-11 g / L, and the temperature of the analysis solution is 53-57°C, characterized in that Here are the steps: Step 1: Gold plating on the anode surface: Reverse the positive and negative poles of the electrolytic cell, and use the anode plate as the cathode; Step 2: Adjust the liquid level of the electrolytic cell: lower the liquid level of the electrolytic cell; Step 3: Analytical electrolysis.

2. The electrodeposition method for analyzing precious liquid by resin slurry method according to claim 1, characterized in that: Step 1: During the gold plating process on the anode surface, the anode current density does not exceed 10A / m 2 .

3. The electrodeposition method for analyzing precious liquid by resin slurry method according to claim 1, characterized in that: Step 1: The gold plating time on the anode surface is not less than 2 hours.

4. The electrodeposition method for analyzing precious liquid by resin slurry method according to claim 1, characterized in that: The chloride ion concentration in the system does not exceed 30 g / L.

5. The electrodeposition method for analyzing precious liquid by resin slurry method according to claim 1, characterized in that: When adjusting the liquid level of the electrolytic cell in step 2, the liquid level is lowered by 5% to 10% of the electrode height.