Method for recovering copper and cobalt metal ions in acidic tailings pond solution of copper cobalt oxide ore

Abstract

The invention relates to the technical field of hydrometallurgy, in particular to a method for recovering copper and cobalt metal ions in a copper oxide cobalt ore acidic tailing pond solution, which comprises the following steps: step S1, mixing and stirring; step S2, filter pressing separation; and S3, returning the filter-pressed liquid to the CCD. The method is characterized in that copper ions and cobalt ions in the acidic tailings pond solution are recovered by utilizing beneficiation wastewater in flotation tailings produced by an enterprise dressing plant under the condition of not additionally adding any medicament, the recovery rate of the copper ions is 60-90%, the recovery rate of the cobalt ions is 50-80%, and the recovery rate of the copper ions is 20-30%. The solution after copper and cobalt ions are recycled serves as washing water to be returned to the CCD countercurrent washing procedure, copper and cobalt ion precipitates are subjected to filter pressing and then serve as concentrate to be returned to the roasting procedure, and the copper and cobalt ions enter a wet smelting system after being subjected to the water quenching procedure; according to the method, metal resource recovery of the acid tailing pond solution and comprehensive utilization of beneficiation wastewater are achieved, potential tapping, efficiency increasing and environment-friendly development of enterprises are assisted, the method has the advantages of being low in cost, simple in process, high in operability and capable of achieving comprehensive utilization of waste, and industrial application of mine enterprises is easy to achieve.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for recovering copper-cobalt metal ions in an acidic tailings pond solution of an oxidized copper-cobalt ore. Background Art

[0002] In the prior art, copper-cobalt oxide ores are mostly produced by wet smelting processes. After open-pit mining, the ore is transported to the smelter yard, and the ore is processed to a qualified particle size by crushing and grinding. Then, sulfuric acid and sodium pyrosulfite are added to adjust the pH and potential values ​​for leaching. The leached slurry is separated by concentration to obtain a high-copper rich solution and a leaching slag bottom flow. The leaching slag bottom flow is then passed through a multi-stage CCD countercurrent washing and thickening machine to produce a low-copper rich solution to recover the copper and cobalt metal ions in the leaching slag bottom flow solution. The leaching slag bottom flow is discharged to the acid tailings pond through the last stage of the CCD thickener. Limited by factors such as ore settling performance, equipment processing capacity, and washing stages, the CCD countercurrent washing efficiency cannot always reach 100%, and there are still some copper and cobalt metal ions in the tailings slag solution discharged to the acid tailings pond.

[0003] In actual production, in order to recover copper and cobalt metal ions in the acid tailings pond, most mining companies use the acid tailings pond solution as washing water, and enter the CCD countercurrent washing process from the last thickener to return the acid tailings pond solution to the hydrometallurgical system. However, due to problems such as equipment operation and process adjustment, the water balance of the hydrometallurgical system is not easy to control, and the amount of acid tailings slag solution discharged is often greater than the amount of liquid returned to the washing water; at the same time, due to the limitation that the CCD countercurrent washing efficiency cannot reach 100%, the metal ion concentration of the discharged acid tailings slag solution is always higher than the metal ion concentration of the washing water, resulting in a gradual increase in copper and cobalt metal ions in the acid tailings pond solution. Therefore, returning the acid tailings pond solution as washing water to the CCD countercurrent washing process is not effective in recovering copper and cobalt metal ions.

[0004] Some patents have publicly reported new progress in the method of recovering valuable metal ions in acidic tailings pond solutions. A Chinese patent with announcement number CN109266837A discloses a method for recovering copper and cobalt from cobalt-containing waste liquid in wet copper smelting. The method first removes impurities from the copper-cobalt waste liquid and then performs nanofiltration concentration separation. Then, an extraction process is used to recover copper, and the raffinate is neutralized and precipitated to recover cobalt. The nanofiltration device used in this method has a complex structure and a low processing capacity, and the subsequent operation and maintenance costs are high. In addition, nanofiltration concentration is performed first and then extraction is performed. The process flow is long and requires a lot of new equipment, which is not conducive to industrial application.

[0005] Also disclosed in the Chinese patent with announcement number CN116162797A is a process for separation and recovery of low-concentration copper and cobalt metals in tailings water from copper and cobalt smelting. The method first adds sodium hydrosulfide to the tailings water to precipitate copper, and then adds calcium carbonate and calcium hydroxide to the filtrate to neutralize and precipitate cobalt after filtering the copper precipitate residue. Although this method achieves a copper precipitation rate of 92%, the added sodium hydrosulfide reagent is easy to generate toxic and harmful hydrogen sulfide gas when it comes into contact with water, which will deteriorate the workplace operating environment, and the added reagents are of many types, which increases the cost of recovering copper and cobalt ions from the tailings solution.

[0006] In view of the above problems, we propose a method for recovering copper and cobalt metal ions from the acidic tailings pond solution of oxidized copper and cobalt ore. Summary of the invention

[0007] The object of the present invention is to provide a method for recovering copper and cobalt metal ions in an acidic tailings pond solution of an oxidized copper and cobalt ore, so as to solve the problems raised in the above-mentioned background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for recovering copper-cobalt metal ions in an acidic tailings pond solution of an oxidized copper-cobalt ore, the method comprising the following steps:

[0010] Step S1, mixing and stirring: pumping the acidic tailings pond solution into the mixing and stirring tank, and introducing the overflow liquid of the copper-cobalt ore flotation tailings thickener into the mixing and stirring tank, and starting the stirring reaction;

[0011] Among them, in the above step S1, since the activator used in the flotation process is sulfide, especially for the oxide ore flotation activator, the amount of the reagent is relatively large, so the tailings solution contains a certain concentration of sulfide ions and hydrogen sulfide ions, and the copper and cobalt metal ions are easily combined with the sulfide ions to form copper sulfide and cobalt sulfide precipitations, and the flotation tailings solution is alkaline, and after mixing with the acidic tailings pond solution, the pH of the acidic solution is increased, so that some of the copper ions and cobalt ions that have not been completely sulfided and precipitated are neutralized and precipitated.

[0012] Step S2, filter press separation: solid-liquid separation is performed on the solid-liquid mixed slurry obtained after the mixing and stirring reaction in step S1 to obtain a filtrate and a filter cake. The filter cake is a copper cobalt sulfide and copper cobalt hydroxide precipitate. The filter cake can be returned to the roasting system as a concentrate after drying and dehydration, and enters the hydrometallurgical system after subsequent roasting and water quenching processes;

[0013] Step S3, returning the liquid after filtration to CCD: the filtrate obtained in step S2 is returned to the CCD countercurrent washing process as washing water. After the acidic tailings pond solution is mixed with the overflow liquid of the flotation tailings thickener, the copper and cobalt metal ions in the acidic tailings pond solution are recovered in the form of precipitation, and the concentration of copper and cobalt metal ions decreases. At this time, returning the filtrate to the CCD countercurrent washing process as washing water is beneficial to improving the washing efficiency of the acidic leaching residue and realizing the comprehensive utilization of the discharged wastewater.

[0014] Preferably, in step S1, the copper-cobalt ore flotation tailings refer to one or more of sulfide ore flotation tailings, oxide ore flotation tailings, mixed ore flotation tailings, etc.

[0015] Preferably, in step S1, the pH value of the acidic tailings pond solution is 1-3, the copper ion content is 1-4 g / L, and the cobalt ion content is 0.2 g / L.

[0016] Preferably, in step S1, the pH value of the flotation tailings thickener overflow liquid is 8-12.

[0017] Preferably, in step S1, the mixing ratio of the acidic tailings pond solution and the flotation tailings thickener overflow liquid is 1:10 to 1:1, and the mixing and stirring time is 0.2 to 2 hours.

[0018] Preferably, in step S1, after the acidic tailings pond solution and the flotation tailings thickener overflow liquid are mixed and stirred for reaction, the precipitation rate of copper ions is 60% to 90%, and the precipitation rate of cobalt ions is 50% to 80%.

[0019] Preferably, in step S2, the precipitated filter cake has a copper content of 10-20% and a cobalt content of 0.5%-5%.

[0020] Preferably, in step S3, the pH value of the liquid after filtration is 4-8, the copper ion content is 0.1-1 g / L, and the cobalt ion content is 0.01-0.5 g / L.

[0021] Preferably, the flotation tailings liquid contains sulfide ions and hydrosulfide ions, the sulfide ion concentration is: 0-500 mg / L, and the hydrosulfide ion concentration is: ≤500 mg / L.

[0022] In summary, the beneficial effects of the present invention are:

[0023] (1) The present invention utilizes the mineral processing wastewater in the flotation tailings produced by the mineral processing enterprise f to recover copper ions in the acidic tailings pond solution without adding any additional reagents. The copper ion recovery rate is 60% to 90%, and the cobalt ion recovery rate is 50% to 80%. The solution after the copper and cobalt ions are recovered is returned to the CCD countercurrent washing process as washing water. The copper and cobalt ion precipitates are filtered and returned to the roasting process as concentrate, and enter the wet smelting system after the water quenching process.

[0024] (2) The present invention utilizes the flotation tailings wastewater produced by the mining enterprise to realize the recovery of copper and cobalt metal ions in the acidic tailings pond solution, and the tailings solution after the copper and cobalt metal ions are recovered is used as washing water to return to the CCD countercurrent washing process to improve the washing efficiency of the acidic leaching residue and realize the comprehensive utilization of the discharged wastewater. The present invention has the characteristics of low cost, simple process, strong operability and comprehensive utilization of waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention provides a schematic process flow diagram of a method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A method for recovering copper-cobalt metal ions in an acidic tailings pond solution of an oxidized copper-cobalt ore, the method comprising the following steps:

[0028] Step S1, mixing and stirring: pumping the acidic tailings pond solution into the mixing and stirring tank, and introducing the overflow liquid of the copper-cobalt ore flotation tailings thickener into the mixing and stirring tank, and starting the stirring reaction;

[0029] Step S2, filter press separation: the solid-liquid mixed slurry obtained after the mixing and stirring reaction in step S1 is subjected to solid-liquid separation to obtain a filtrate and a filter cake, the filter cake is copper cobalt sulfide and copper cobalt hydroxide precipitates, the filter cake is dried and dehydrated, and returned to the roasting system as a concentrate, and enters the hydrometallurgical system after subsequent roasting and water quenching processes;

[0030] Step S3, filtrate returns to CCD: the filtrate obtained in step S2 is returned to the CCD countercurrent washing process as washing water, and after the acidic tailings pond solution is mixed with the overflow liquid of the flotation tailings thickener, the copper and cobalt metal ions in the acidic tailings pond solution are recovered in the form of precipitation.

[0031] In some preferred embodiments, in step S1, the copper-cobalt ore flotation tailings refer to one or more of sulfide ore flotation tailings, oxide ore flotation tailings, mixed ore flotation tailings, etc.

[0032] In some preferred embodiments, in step S1, the pH value of the acidic tailings pond solution is 1-3, the copper ion content is 1-4 g / L, and the cobalt ion content is 0.1-2 g / L.

[0033] In some preferred embodiments, in step S1, the pH value of the flotation tailings thickener overflow liquid is 8-12.

[0034] In some preferred embodiments, in step S1, the mixing ratio of the acidic tailings pond solution and the flotation tailings thickener overflow liquid is 1:10 to 1:1, and the mixing and stirring time is 0.2 to 2 hours.

[0035] In some preferred embodiments, in step S1, after the acidic tailings pond solution and the flotation tailings thickener overflow liquid are mixed and stirred for reaction, the precipitation rate of copper ions is 60% to 90%, and the precipitation rate of cobalt ions is 50% to 80%.

[0036] In some preferred embodiments, in step S2, the filter cake has a copper content of 10-20% and a cobalt content of 0.5%-5%.

[0037] In some preferred embodiments, in step S3, the pH value of the filtrate is 4-8, the copper ion content is 0.1-1 g / L, and the cobalt ion content is 0.01-0.5 g / L.

[0038] In some preferred embodiments, the flotation tailings liquid contains sulfide ions and hydrosulfide ions, the sulfide ion concentration is 0-500 mg / L, and the hydrosulfide ion concentration is ≤ 500 mg / L. Specific embodiment 1:

[0040] S1. Take 1000mL of an acidic tailings pond solution of a copper-cobalt oxide mine in a beaker, with an initial pH value of 2.46, a copper ion content of 2.56g / L, and a cobalt ion content of 0.67g / L;

[0041] S2. The pH value of the overflow liquid of the flotation tailings thickener of the oxide ore produced by the ore dressing workshop is 10.09. Take 2000 mL of the overflow liquid of the flotation tailings thickener and add it into a beaker and mix it with the acidic tailings pond solution and stir it to react. After the reaction time is 40 minutes, the pH value of the mixed solution is 4.84. Stop the reaction and filter to obtain the filtrate and filter cake residue.

[0042] The results of the analysis showed that the copper ion content of the filtrate was 0.23 g / L and the cobalt ion content was 0.08 g / L. The copper content of the filter cake residue was 13.09% and the cobalt content was 3.01%. The copper ion precipitation rate was 73.05% and the cobalt ion precipitation rate was 64.18%. Specific embodiment 2:

[0044] S1. Take 1000mL of an acidic tailings pond solution of a copper-cobalt oxide mine in a beaker, with an initial pH value of 2.46, a copper ion content of 2.56g / L, and a cobalt ion content of 0.67g / L;

[0045] S2. The pH value of the mixed ore flotation tailings thickener overflow liquid produced by the ore dressing workshop is 8.98. Take 3000 mL of the flotation tailings thickener overflow liquid and add it to a beaker and mix it with the acidic tailings pond solution for stirring and reaction. After the reaction time is 50 minutes, the pH value of the mixed solution is 5.82. Stop the reaction and filter to obtain the filtrate and filter cake residue.

[0046] The results of analysis showed that the copper ion content of the filtrate was 0.15 g / L and the cobalt ion content was 0.04 g / L. The copper content of the filter cake residue was 15.23% and the cobalt content was 3.66%. The copper ion precipitation rate was 82.81% and the cobalt ion precipitation rate was 76.12%.

[0047] Comparative Example 1

[0048] S1. Take 1000mL of an acidic tailings pond solution of a copper-cobalt oxide mine in a beaker, with an initial pH value of 2.46, a copper ion content of 2.56g / L, and a cobalt ion content of 0.67g / L;

[0049] S2. Use 10% NaOH solution to adjust the pH of deionized water to 10.15, and take 2000 mL and add it to a beaker to mix with the acidic tailings pond solution and stir to react. After 40 minutes of reaction time, the pH value of the mixed solution is 4.88. Stop the reaction and filter to obtain the filtrate and filter cake residue.

[0050] The results of the analysis showed that the copper ion content of the filtrate was 0.36 g / L and the cobalt ion content was 0.15 g / L. The copper content of the filter cake residue was 9.57% and the cobalt content was 1.42%. The copper ion precipitation rate was 57.81% and the cobalt ion precipitation rate was 32.84%.

[0051] The present invention does not elaborate on some of the well-known technologies that belong to those skilled in the art.

[0052] Table 4 Results of specific examples 1-2

[0053]

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore, characterized in that: The method comprises the following steps: Step S1, mixing and stirring: pumping the acidic tailings pond solution into the mixing and stirring tank, and introducing the overflow liquid of the copper-cobalt ore flotation tailings thickener into the mixing and stirring tank, and starting the stirring reaction; Step S2, filter press separation: the solid-liquid mixed slurry obtained after the mixing and stirring reaction in step S1 is subjected to solid-liquid separation to obtain a filtrate and a filter cake, the filter cake is copper cobalt sulfide and copper cobalt hydroxide precipitates, the filter cake is dried and dehydrated, and returned to the roasting system as a concentrate, and enters the hydrometallurgical system after subsequent roasting and water quenching processes; Step S3, filtrate returns to CCD: the filtrate obtained in step S2 is returned to the CCD countercurrent washing process as washing water, and after the acidic tailings pond solution is mixed with the overflow liquid of the flotation tailings thickener, the copper and cobalt metal ions in the acidic tailings pond solution are recovered in the form of precipitation.

2. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In step S1, the copper-cobalt ore flotation tailings refer to one or more of sulfide ore flotation tailings, oxide ore flotation tailings, mixed ore flotation tailings, etc.

3. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In the step S1, the pH value of the acidic tailings pond solution is 1-3, the copper ion content is 1-4 g / L, and the cobalt ion content is 0.2 g / L.

4. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In the step S1, the pH value of the flotation tailings thickener overflow liquid is 8-12.

5. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In the step S1, the mixing ratio of the acidic tailings pond solution and the flotation tailings thickener overflow liquid is 1:10 to 1:1, and the mixing and stirring time is 0.2 to 2 hours.

6. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In the step S1, after the acidic tailings pond solution and the flotation tailings thickener overflow liquid are mixed and stirred for reaction, the precipitation rate of copper ions is 60% to 90%, and the precipitation rate of cobalt ions is 50% to 80%.

7. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In step S2, the filter cake has a copper content of 10-20% and a cobalt content of 0.5%-5%.

8. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: In step S3, the filtrate has a pH value of 4-8, a copper ion content of 0.1-1 g / L, and a cobalt ion content of 0.01-0.5 g / L.

9. The method for recovering copper and cobalt metal ions from an acidic tailings pond solution of an oxidized copper and cobalt ore according to claim 1, characterized in that: The flotation tailings liquid contains sulfide ions and hydrogen sulfide ions, the sulfide ion concentration is: 0-500mg / L, and the hydrogen sulfide ion concentration is: ≤500mg / L.

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