CN1310242A

CN1310242A - Zn-Co sludge treating method

Info

Publication number: CN1310242A
Application number: CN00102775A
Authority: CN
Inventors: 李国民; 刘诚; 董爱国; 刘金山
Original assignee: BEIJING GENERAL NON-FERROUS METALLURGY DESIGN INST
Current assignee: BEIJING GENERAL NON-FERROUS METALLURGY DESIGN INST; Beijing General Research Institute for Non Ferrous Metals
Priority date: 2000-02-21
Filing date: 2000-02-21
Publication date: 2001-08-29

Abstract

The present invention relates to the method of treating Zn-Co sludge at 40-90 deg.c while stirring, adding zinc powder to eliminate impurity, filtering, ammonia evaporation of pure zinc-ammonia liquid, re-filtering and calcination at 400-700 deg.c to obtain active zinc oxide with 99 % over purity. The process of the present invention is simple, low in the anticorrosive requirement of equipment, easy in operation, low in loss and high in metal recovery rate.

Description

New method for treating zinc-cobalt slag

The invention relates to a method for extracting active zinc oxide or other zinc products from zinc-cobalt slag, in particular to a method for extracting active zinc oxide or other zinc products from zinc-cobalt slag or similar materials generated in zinc hydrometallurgy liquid purification.

At present, a great amount of zinc-cobalt slag is generated in deep liquid purification of some wet zinc-smelting plants. At present, no good recovery method exists in China, and tens of thousands of tons of the waste water are piled up at present. The cobalt removal by antimony salt produces a new zinc-cobalt residue which can be treated by acid leaching, but the index is unstable, if the residue is stored for a long time, part of the zincAfter the cobalt is oxidized, the acid leaching method is not suitable because the cobalt is leached in a large amount while the zinc is leached in a large amount, and the cobalt is difficult to remove when the cobalt returns to the system. Since the slag contains a large amount of SO₄ ^2-If the fire method is used for treatment, not only the process and the equipment are complex, but also the problem of environmental pollution is brought.

The present invention aims at providing a new method for treating zinc-cobalt slag, and the slag is treated by a wet method to prepare active zinc oxide or other zinc products. Can be used as a working procedure of zinc hydrometallurgy in a zinc hydrometallurgy plant.

The principle of the invention is to utilize the fact that zinc and ammonia can generate a series of complex ions and chelates with cyclic structures, and the complexes are mostly stable in aqueous solution.

The main reaction equation is:

other part metals such as cobalt, copper, etc. and Cu (NH)₃)₄ ²⁺、Co(NH₃)₄ ²⁺The form of the plasma is transferred into the solution, namely:

removing impurities such as copper, cobalt and the like in the solution by using zinc powder replacement, wherein the chemical reaction comprises the following steps:

and returning the obtained pure zinc-ammonia solution to a zinc hydrometallurgy (jarosite iron removal) system, or performing ammonia leaching on the material, removing impurities, then evaporating ammonia, filtering, and calcining to prepare the active zinc oxide.

The chemical reaction of ammonia evaporation and calcination is as follows:

ammonia distillation

Calcination of

In the ammonia leaching process, the leaching speed is slow when the leaching temperature is low, the ammonia volatilization is serious when the temperature is too high, the metal leaching is not facilitated, and the temperature is generally controlled to be 40-90 ℃. The leaching time is generally not more than 5 hours. The impurity removing temperature is the same as the ammonia leaching temperature, the impurities such as copper, cobalt and the like are removed by zinc powder, and the amount of the zinc powder added in different materials is different. Solvent extraction can also be used to remove copper and cobalt from the ammonia leach solution. If the material contains arsenic, iron salt or ferric hydroxide can be used for adsorption to remove arsenic.

The invention is described below with reference to the accompanying drawings.

FIG. 1 is a process flow diagram of the present invention.

Referring to fig. 1, the method of the invention is that 10 parts of zinc-cobalt slag is stirred and ammonia-leached under the condition of heating to 40-90 ℃, 1-2 parts of zinc powder is added to remove impurities and filter, then pure zinc-ammonia liquid is ammonia-evaporated and filtered again, and then calcined under the condition of 400-700 ℃, so as to obtain the active zinc oxide with the purity of more than 99%.

If the zinc-cobalt slag contains copper and arsenic impurities, the following method is adopted for treating the zinc-cobalt slag: 10 parts of zinc-cobalt slag are stirred for ammonia leaching under the condition of heating to 40-90 ℃, 1-2 parts of zinc powder are added for removing copper and cobalt, 1-3 parts of iron salt are added for removing arsenic, the mixture is filtered, then pure zinc-ammonia liquid is evaporated with ammonia and filtered, and then the mixture is calcined under the condition of 400-700 ℃, so that the active zinc oxide with the purity of more than 99 percent is obtained.

Referring to fig. 1, in the above method, the obtained pure zinc-ammonia solution can be returned to a zinc hydrometallurgy (jarosite deironing) system to continue to refine zinc.

The impurities of copper and cobalt in the ammonia leaching solution can also be removed by an extraction method, 10 parts of zinc-cobalt slag are stirred at 40-90 ℃ for ammonia leaching and filtration, the filtrate is used for extracting cobalt and copperby 10-60 parts of a ketone oxime extractant, the loaded organic solvent is used for back extracting cobalt by 10-60 parts of dilute sulfuric acid solution with the concentration of 0.1-0.5mol/L, then, the copper is back extracted by 5-10 parts of sulfuric acid solution with the concentration of 0.7-1.3mol/L to obtain cobalt sulfate and copper sulfate, and the zinc-containing raffinate is returned to a zinc hydrometallurgy (yellow iron vitriol deironing) system.

Example (b):

1. 100Kg of zinc-cobalt slag in a certain factory is stirred and ammonia-soaked under the condition of heating to 40-90 ℃, 15Kg of zinc powder is added to remove impurities and filter, then the filtered pure zinc-ammonia solution is ammonia-evaporated and filtered again, and then calcined under the condition of 400-700 ℃ to obtain the active zinc oxide with the purity of more than 99 percent.

2. 100Kg of zinc-cobalt slag containing copper and arsenic in a certain plant is stirred and ammonia-leached at 40-90 deg.C, 20Kg of zinc powder is added to remove copper and cobalt, and 20Kg of ferric hydroxide is added to remove arsenic, the mixture is filtered, and then the pure zinc-ammonia solution after filtration is ammonia-evaporated, filtered again, and calcined at 400-700 deg.C to obtain active zinc oxide with purity of over 99%.

3. A certain factory adopts a solvent extraction method to remove copper and cobalt from ammonia leaching solution, and the specific method comprises the following steps: 10 parts of zinc-cobalt slag are stirred at 40-90 ℃ for ammonia leaching and filtration, the filtrate is extracted with 50 parts of oxime extractant to obtain cobalt and copper, the loaded organic cobalt is back-extracted with 50 parts of dilute sulfuric acid solution with the concentration of 0.3mol/L, then the copper is back-extracted with 3.5 parts of sulfuric acid solution with the concentration of 1mol/L to obtain cobalt sulfate and copper sulfate, and the zinc-containing raffinate is returned to a zinc hydrometallurgy (jarosite deironing) system.

The method has the advantages of simple process, low equipment corrosion prevention requirement, easy operation, easy impurity removal, low consumption and high metal recovery rate.

Claims

1. A new method for treating zinc-cobalt slag is characterized in that: 10 parts of zinc-cobalt slag is stirred and ammonia-leached under the condition of heating to 40-90 ℃, 1-2 parts of zinc powder is added for impurity removal and filtration, then pure zinc-ammonia liquid is ammonia-evaporated and filtered again, and then calcined under the condition of 400-700 ℃, so that the active zinc oxide with the purity of more than 99 percent is obtained.

2. A new method for treating zinc-cobalt slag is characterized in that: 10 parts of zinc-cobalt slag are stirred for ammonia leaching under the condition of heating to 40-90 ℃, 1-2 parts of zinc powder are added for removing copper and cobalt, 1-3 parts of iron salt are added for removing arsenic, the mixture is filtered, then pure zinc-ammonia liquid is evaporated with ammonia and filtered, and then the mixture is calcined under the condition of 400-700 ℃, so that the active zinc oxide with the purity of more than 99 percent is obtained.

3. A new method for treating zinc-cobalt slag according to claim 1 or 2, characterized in that: the obtained pure zinc-ammonia solution can be returned to a zinc hydrometallurgy (jarosite iron removal) system.

4. A new method for treating zinc-cobalt slag is characterized in that: 10 parts of zinc-cobalt slag is stirred at 40-90 ℃ for ammonia leaching and filtration, the filtrate is used for extracting cobalt and copper by 10-60 parts of a ketone oxime extractant, the loaded organic solvent is used for back extracting cobalt by 10-60 parts of dilute sulfuric acid solution with the concentration of 0.1-0.5mol/L, then the sulfuric acid solution with the concentration of 0.7-1.3mol/L is used for back extracting copper by 5-10 parts, cobalt sulfate and copper sulfate are obtained, and the zinc-containing raffinate is returned to a zinc hydrometallurgy (jarosite deironing) system.