Method for separating and recovering copper and cobalt from cobalt-containing low-copper raffinate

Abstract

The invention discloses a method for separating and recovering copper and cobalt from cobalt-containing low-copper raffinate, and belongs to the technical field of hydrometallurgy. The cobalt-containing low-copper raffinate is a solution containing impurity ions of copper, cobalt, iron and manganese produced after leaching and copper extraction in the wet smelting process of the copper oxide cobalt ore, the concentration of the copper ions is 0.01-1.0 g / L, and the concentration of the cobalt ions is 0.1-10 g / L. Adding 1-20g / L of neutralizer into the cobalt-containing low-copper raffinate, carrying out neutralization and deacidification reaction, and filtering to obtain neutralized slag and deacidified liquid with the pH value of 1.5-2.5; adding iron powder of which the mass is 0.5-5.0 times of the theoretical amount of copper deposition into the deacidified liquid, and carrying out a copper deposition reaction under the assistance of ultrasonic waves to obtain wet slag and a liquid after copper deposition; after iron and manganese are removed from the solution after copper deposition, cobalt hydroxide is produced; and dehydrating the wet slag to form precipitated dry slag, and feeding the precipitated dry slag into a refining system to recycle copper or recycle the precipitated dry slag as high-grade copper slag. According to the separation and recovery method, the technological process is simplified, the copper and cobalt separation effect and efficiency are effectively improved, the copper slag grade is improved, and cost reduction and efficiency improvement of enterprises are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy, and in particular relates to a method for separating and recovering copper and cobalt from cobalt-containing low-copper raffinate. Background Art

[0002] Copper, cobalt, nickel, iron, etc. are often coexistent in one or more minerals due to their similar geochemical properties, and cobalt often coexists with copper or nickel, which is called copper-cobalt ore or nickel-cobalt ore. Copper-cobalt ore is mainly divided into oxide ore, mixed ore and sulfide ore. The treatment method of oxide copper-cobalt ore is stirring leaching-extraction-electrodeposition-iron removal and cobalt precipitation. The cobalt-containing raffinate after copper extraction is generally produced by impurity removal-cobalt precipitation process to produce cobalt salts or cobalt compounds.

[0003] Domestic and foreign researchers have conducted extensive research on copper removal from cobalt-containing low-copper raffinate. The existing treatment process mainly uses one or two stages of iron removal to increase the pH of the iron removal process, so that copper ions are precipitated into the iron removal slag. This process can achieve a relatively ideal copper removal effect, but the precipitation pH of copper and cobalt is relatively close. The method of increasing the system pH to remove copper will cause some cobalt to precipitate into the iron removal slag, resulting in serious cobalt loss.

[0004] Based on this, the present invention aims to propose a method for separating and recovering copper and cobalt from cobalt-containing low-copper raffinate, simplify the process flow, improve the copper and cobalt separation effect and efficiency, increase the copper slag grade, and reduce costs and increase efficiency for enterprises. Summary of the invention

[0005] The object of the present invention is to provide a method for separating and recovering copper and cobalt from cobalt-containing low-copper raffinate.

[0006] The object of the present invention is achieved in that the method for separating and recovering copper and cobalt from a cobalt-containing low-copper raffinate comprises the following steps: A neutralizing agent in an amount of 1 to 20 g / L is added to the cobalt-containing and low-copper raffinate to carry out a neutralization and acid reduction reaction, and after filtration, a neutralized residue and an acid-reduced liquid with a pH value of 1.5 to 2.5 are obtained.

[0007] Add iron powder in an amount equivalent to 0.5 to 5.0 times the theoretical amount of copper precipitation to the acid-reduced liquid, and, under the assistance of ultrasound, the copper precipitation reaction is performed to obtain wet slag and copper precipitation liquid.

[0008] After the copper precipitation liquid is free of iron and manganese, it is used to produce cobalt hydroxide.

[0009] The wet slag is dehydrated to form precipitated dry slag, which is sent to the refining system to recover copper or recovered as high-grade copper slag.

[0010] The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical smelting of copper-cobalt oxide ore, wherein the copper ion concentration is 0.01-1.0 g / L and the cobalt ion concentration is 0.1-10 g / L.

[0011] The neutralizing agent includes a hydroxyl radical that can directly or indirectly provide OH - Ionic alkaline substances.

[0012] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The present application provides a method for separating and recovering copper and cobalt from a cobalt-containing low-copper raffinate, which uses ultrasonic enhanced auxiliary reduction of iron powder to precipitate copper. The Fe ions introduced in the process can be removed in a subsequent iron removal process, so that the method does not introduce non-system impurities throughout the entire process.

[0013] The present application provides a method for separating and recovering copper and cobalt from a cobalt-containing low-copper raffinate, which uses ultrasonic enhanced auxiliary reduction of iron powder to precipitate copper. The process flow is simplified, the equipment has strong universal interchangeability, the separation effect is good, and the grade of the obtained copper slag is ≥85%.

[0014] The technical solution of the present invention solves the problems of large consumption of auxiliary materials and reagents, unsatisfactory separation effect and low product recovery rate under the existing technical conditions.

[0015] When the sound wave pressure of ultrasonic vibration in liquid reaches one atmosphere, the peak pressure of ultrasonic wave can reach vacuum or negative pressure, but there is no negative pressure in fact, so a great force is generated in the liquid, which pulls the liquid molecules into cavities. This cavity is very close to vacuum, and it ruptures when the ultrasonic pressure reaches the maximum in the reverse direction. This shock wave phenomenon generated by the rupture of countless tiny cavitation bubbles is called "cavitation" phenomenon.

[0016] The new ultrasonic cavitation-iron powder replacement copper deposition process in the technical solution of the present invention utilizes two effects of ultrasonic cavitation: (1) The growth and collapse of cavitation nuclei generate strong shear forces inside the solution. The cavitation effect of ultrasound can greatly increase the rate of heterogeneous reactions, achieve uniform mixing between heterogeneous reactants, accelerate the diffusion of reactants and products, promote the formation of a new solid phase of the replacement product, and separate the unreacted iron powder from the replacement product, exposing the active surface of the iron powder, reducing the diffusion layer, and promoting the contact between Cu ions and iron powder, thereby improving the copper grade of copper slag.

[0017] (2) The instantaneous high temperature and high pressure (local pressure peak reaches hundreds or even thousands of atmospheres, and the instantaneous temperature is over 1000K) generated by ultrasonic cavitation is used to accelerate the replacement reaction between iron powder and Cu. The reaction rate is incomparable to the traditional iron powder replacement temperature of 90°C, thereby increasing the replacement speed and reducing iron powder consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the process flow of the technical solution described in the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0020] The method for separating and recovering copper and cobalt from a cobalt-containing low-copper raffinate comprises the following steps: A neutralizing agent in an amount of 1 to 20 g / L is added to the cobalt-containing and low-copper raffinate to carry out a neutralization and acid reduction reaction, and after filtration, a neutralized residue and an acid-reduced liquid with a pH value of 1.5 to 2.5 are obtained.

[0021] Add iron powder in an amount equivalent to 0.5 to 5.0 times the theoretical amount of copper precipitation to the acid-reduced liquid, and, under the assistance of ultrasound, the copper precipitation reaction is performed to obtain wet slag and copper precipitation liquid.

[0022] After the copper precipitation liquid is free of iron and manganese, it is used to produce cobalt hydroxide.

[0023] The wet slag is dehydrated to form precipitated dry slag, which is sent to the refining system to recover copper or recovered as high-grade copper slag.

[0024] The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical smelting of copper-cobalt oxide ore, wherein the copper ion concentration is 0.01-1.0 g / L and the cobalt ion concentration is 0.1-10 g / L.

[0025] The neutralizing agent includes a hydroxyl radical that can directly or indirectly provide OH - Ionic alkaline substances.

[0026] The preferred dosage of the neutralizing agent is 8-15 g / L solution (cobalt-containing low-copper raffinate).

[0027] The neutralizing agent is any one or more of carbonate, metal oxide, and hydroxide, preferably carbonate.

[0028] The pH value of the acid-reduced liquid is 2.0.

[0029] The preferred amount of the iron powder is 1.5 to 3.0 times the theoretical amount of copper plating.

[0030] The temperature of the neutralization and acid reduction reaction is 5-100° C., and the time is 5-360 min. The preferred temperature is 20-40° C., and the preferred time is 60-120 min.

[0031] The ultrasonic power of the ultrasonic-assisted method is 10-100 KW, preferably 10-30 KW.

[0032] The temperature of the copper deposition reaction is 5-100° C., and the time is 5-360 min. The preferred temperature is 20-40° C., and the preferred time is 20-30 min.

[0033] The removal of iron and manganese is any combination of oxidation reaction and neutralization reaction.

[0034] The refining is either fire refining or electrolytic refining.

[0035] The copper grade of the wet slag is ≥85%.

[0036] The reaction equation involved is: Cu 2+ +Fe→Fe 2+ +Cu.

[0037] Example 1 Take 1000mL of cobalt-containing low-copper raffinate, the main components of which are: copper 135.38mg / L, cobalt 1.08g / L, iron 213.18mg / L, manganese 2.27g / L, and sulfuric acid 12.64g / L.

[0038] 8.98 g / L calcium carbonate was added to the cobalt-containing and low-copper raffinate, and the reaction was carried out at 25-30°C for 60 min. After the neutralization and acid reduction reaction was completed, the solution was filtered to obtain neutralized slag and acid reduction liquid with a pH value of 1.5. The neutralized slag contained 0.0028% Co and 0.0056% Cu. The recoveries of Co and Cu in the neutralization and acid reduction process were 99.97% and 99.59%, respectively.

[0039] Take 1000mL of the acid-reduced liquid, add reduced iron powder equivalent to 2.5 times the theoretical amount of copper precipitation, react at 30-35°C for 25min under the assistance of 20KW ultrasonic wave, filter after the copper precipitation reaction to obtain wet slag and copper precipitation liquid; the copper precipitation liquid contains Cu 17.90mg / L, and the slag contains Cu 89.05%.

[0040] After the copper precipitation liquid is free of iron and manganese, it is used to produce cobalt hydroxide; the wet slag is dehydrated to form precipitated dry slag, which is sent to the refining system to recover copper.

[0041] Example 2 Take 1000mL of cobalt-containing low-copper raffinate, the main components of which are: copper 118.22mg / L, cobalt 1.00g / L, iron 223.54mg / L, manganese 1.97g / L, and sulfuric acid 11.92g / L.

[0042] 10.50 g / L calcium carbonate was added to the cobalt-containing and low-copper raffinate, and the reaction was carried out at 20-25°C for 90 min. After the neutralization and acid reduction reaction was completed, the solution was filtered to obtain neutralized slag and acid reduction liquid with a pH value of 2.0. The neutralized slag contained 0.005% Co and 0.001% Cu, and the recoveries of Co and Cu in the pre-neutralization process were 99.94% and 99.90%, respectively.

[0043] Take 1000mL of the acid-reduced liquid, add reduced iron powder equivalent to 3 times the theoretical amount of copper precipitation, react at 35-40℃ for 20min under the assistance of 30KW ultrasonic wave, filter after the copper precipitation reaction to obtain wet slag and copper precipitation liquid; the copper precipitation liquid contains Cu13.72mg / L, and the slag contains Cu 89.41%.

[0044] After the copper precipitation liquid is free of iron and manganese, it is used to produce cobalt hydroxide; the wet slag is dehydrated to form precipitated dry slag, which is sent to the refining system to recover copper.

[0045] Example 3 Take 1000mL of cobalt-containing low-copper raffinate, the main components of which are: copper 124.11mg / L, cobalt 1.38g / L, iron 219.84mg / L, manganese 2.06g / L, and sulfuric acid 12.35g / L.

[0046] 14.50 g / L sodium carbonate was added to the cobalt-containing and low-copper raffinate, and the reaction was carried out at 35-40°C for 120 min. After the neutralization and acid reduction reaction was completed, the reaction was filtered to obtain neutralized slag and acid reduction liquid with a pH value of 2.5. The neutralized slag contained 0.0041% Co and 0.0023% Cu. The recoveries of Co and Cu in the neutralization and acid reduction process were 99.95% and 99.78%, respectively.

[0047] Take 1000mL of the acid-reduced liquid, add reduced iron powder equivalent to 1.5 times the theoretical amount of copper precipitation, react for 30min at 20-25℃ with the assistance of 10KW ultrasonic wave, filter after the copper precipitation reaction to obtain wet slag and copper precipitation liquid; the copper precipitation liquid contains Cu 15.25mg / L, and the slag contains Cu 89.27%.

[0048] After the copper precipitation liquid is free of iron and manganese, it is used to produce cobalt hydroxide; the wet slag is dehydrated to form precipitated dry slag, which is directly recovered as high-grade copper slag.

Claims

1. A method for separating and recovering copper and cobalt from a cobalt-containing low-copper raffinate, characterized in that Including the following processes: Adding a neutralizing agent in an amount of 1 to 20 g / L of solution to the cobalt-containing low-copper raffinate to perform a neutralization and acid reduction reaction, and filtering to obtain a neutralized residue and an acid-reduced liquid having a pH value of 1.5 to 2.5; Adding iron powder equivalent to 0.5 to 5.0 times the theoretical amount of copper precipitation into the acid-reduced solution, and performing copper precipitation reaction under the assistance of ultrasound to obtain wet slag and copper precipitation solution; After the copper precipitation liquid is freed of iron and manganese, it is used to produce cobalt hydroxide; The wet slag is dehydrated to form precipitated dry slag, which is sent to the refining system to recover copper or recovered as high-grade copper slag; The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical smelting of copper-cobalt oxide ore, wherein the copper ion concentration is 0.01-1.0 g / L and the cobalt ion concentration is 0.1-10 g / L; The neutralizing agent includes a hydroxyl radical that can directly or indirectly provide OH - Ionic alkaline substances.

2. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The amount of the neutralizer used is 8-15 g / L solution.

3. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The neutralizing agent is any one or more of carbonate, metal oxide and hydroxide.

4. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The amount of the iron powder used is 1.5 to 3.0 times the theoretical amount of copper plating.

5. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The temperature of the neutralization and acid reduction reaction is 5-100° C., and the time is 5-360 minutes.

6. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The ultrasonic power of the ultrasonic-assisted method is 10-100KW.

7. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The temperature of the copper deposition reaction is 5-100° C. and the time is 5-360 min.

8. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The removal of iron and manganese is any combination of oxidation reaction and neutralization reaction.

9. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The refining is either pyro-refining or electro-refining.

10. The method for separating and recovering copper and cobalt according to claim 1, characterized in that: The copper grade of the slag is ≥85%.

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