JPS63129020A - Method for recovering cobalt carbonate in zinc refining stage - Google Patents

Abstract

PURPOSE:To easily recover cobalt carbonate at a low cost and to obtain a high-grade copper refining material by removing zinc from the clarified residue obtained from a zinc refining stage, then removing copper from the obtained acid-cleaned residue, adding H2S to the soln. to remove As, Cd, and Cu, adding soda ash to the cleaned soln., and filtering the precipitate. CONSTITUTION:Water and sulfuric acid are added to the clarified residue produced from the clarifying stage of zinc refining and contg. Cu, Zn, Cd, and As as the essential components in addition to Co to control the pH to 2-4, the liq. is agitated and cleaned with an acid, the precipitate is filtered and washed with water to elute the greater part of Cd, and the obtained acid-cleaned soln. is separated to obtain the acid-cleaned residue. Water and sulfuric acid are added to the residue to control the pH to 2-3, the soln. is heated to 50-60 deg.C, air is blown in to selectively dissolve Co, the precipitate is filtered and washed to separate a copper-contg. residue, and a soln. contg. Co, etc., is obtained. Na2S and sulfuric acid are then added to the soln. and heated to about 60 deg.C to precipitate AsS, CdS, and CuS by the generated H2S, the precipitated sulfides are separated and removed, sulfuric acid is added to the filtrate to control the pH to <=3, hence the filtrate is clarified, soda ash is added to the clarified filtrate at 60-80 deg.C to adjust the pH to 6-9, and the obtained precipitate is filtered and washed with water.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for recovering cobalt carbonate from a clean residue produced in a cleaning step in zinc smelting.

<Prior art and problems> As shown in Figure 6, zinc smelting involves a roasting process to remove sulfur (S) from zinc concentrate, a melting process to dissolve the contained metal in sulfuric acid, and zinc (Zn). The process consists of a cleaning process to remove other metals, and an electrolytic process to electrolytically extract Zn.

As shown in FIG. 7, the cleaning process is comprised of several cleaning processes, and finally a third cleaning solution with a high Zn concentration is supplied to the electrolytic process.

Here, the first cleaning residue generated in the first cleaning step is the first cleaning residue.
It has the composition shown in the table and contains expensive cobalt (Co).

However, since the first cleaned residue has a low CO content and is not easy to separate from each other, it has been used as a raw material for copper smelting, and CO has not been recovered. In addition, even if this first-purification residue is used as a raw material for copper smelting, highly toxic arsenic (
Because it contains many impurities such as As), its value is low.

The present invention has been made in view of the above-mentioned conventional circumstances, and is a method for realizing Co recovery from the clean residue obtained in the cleaning process of zinc smelting, and further producing an advantageous copper smelting raw material with a high copper grade in the intermediate stage. The purpose is to provide

Means for Solving Problems> The method for recovering cobalt carbonate according to the present invention mainly collects Cu and Zn in addition to Co obtained in the zinc smelting process.

Water and sulfuric acid are added to the cleaned residue containing Cd and As, a pickling solution containing mainly Zn is separated to produce a pickling solution containing Co, and water and sulfuric acid are added to the pickling solution. Furthermore, by blowing air, a dissolved residue containing mainly Cu is separated to produce a dissolved solution containing Co, and by adding hydrogen sulfide gas to the dissolved solution, sulfides of mainly As, Cd, and Cu are produced. The method is characterized in that a cleaning residue containing Co is separated to produce a cleaning solution containing Co, and the cleaning solution is added with soda ash and filtered to recover cobalt carbonate.

That is, this cobalt carbonate is recovered by carrying out the steps shown in FIG.

First, in the pickling process, the first cleaned residue produced by the zinc smelting described above and having the composition shown in Table 1 is repulped with water and sulfuric acid (preferably P12 to P4).
After adjusting the temperature to about H3 and stirring for about 2 hours, it is filtered and washed with water to remove most of the Zn and cadmium (Cd) in the first cleaning residue.
The pickling solution is separated into a pickling solution in which a part of the solution is released and a pickling solution containing other components such as Co.

Next, in the cobalt dissolution step, the pickling solution is repulped with water, adjusted to pH 2 to 3 with sulfuric acid, heated to a temperature of about 50 to 60° C., and stirred for about 20 hours while blowing air.

As a result, the Cot1 degree in the liquid increases with time, while the copper (Cu) concentration decreases, and Co is selectively dissolved. This slurry is then filtered and washed with water to separate it into a dissolved residue mainly containing Cu and a dissolved solution containing other components such as Co, as shown in Table 2.

(Table 2) Next, in the cleaning step, sodium sulfide and sulfuric acid were added to the above solution and stirred for about 1 hour at a temperature of about 60°C. Mainly from As.

Cd and Cu are precipitated and removed as sulfides.

Note that instead of reacting sodium sulfide and sulfuric acid, hydrogen sulfide gas may be added directly, and this solution may be cleaned as it is, but in order to reduce the loss of Co during cleaning, sulfuric acid may be added. The pH of the solution is adjusted to 3 or less, preferably about 1, and then cleaned. This is because when the pH is lowered to 1 or less, the loss of Co decreases, but the amount of soda ash added increases during the recovery of cobalt carbonate, which will be described later.
A pH of about 1 is preferable in view of the economics of this Co loss and the amount of added soda ash, and the cleaned solution is filtered to separate it into the cleaning residue containing the sulfide and the cleaning liquid containing Co.

Next, the above cleaning solution is heated to a liquid temperature of about 60-80°C, soda ash is added, and stirred for about 2 hours to finally reach a PFI of 6-80°C.
Make it 9. Then, the obtained precipitate is filtered and washed with water to recover cobalt carbonate having the composition shown in Table 3. Here, since cobalt carbonate has low solubility and good sedimentation and permeability, it can be recovered at an extremely good collection rate.

(Table 3) Note that the pickling solution obtained in the above pickling step contains a large amount of Zn, and therefore is used as a raw material for zinc smelting. In addition, the dissolution residue obtained in the above cobalt dissolution step contains Zn, Cd, C
Since a large amount of As has been removed, it can be used in copper smelting as a higher quality raw material than before.

<Example> Examples of the present invention are shown below.

(Example 1) 40 kg of the pickling source obtained by pickling the first cleaning residue was repulped with water 1201 in a stainless steel tank, sulfuric acid was added to adjust the pH, and the liquid temperature was 50 to 60°C. 600j of air!
The treatment was carried out for 6 hours while blowing at 1/min. The pH of the treatment was kept constant for 6 hours while adding sulfuric acid dropwise.

The test was conducted five times by changing the treatment P), and from the analytical values of the first clean residue, dissolved residue, and dissolved solution, Co, Cu,
The dissolution rate of As was calculated, and the results shown in FIG. 2 were obtained. In this example, it is most preferable to set PI to about 3, and it can be seen that the separation of CO from Cu and As and the dissolution of Co are achieved most efficiently.

(Example 2) In a test similar to Example 1, sulfuric acid was added and the initial pH was adjusted to 1.
5 and then treated for 24 hours.

The concentration of Co and Cu in the solution and P according to this test
Figure 3 shows the change in H over time, and Table 4 shows the analytical values for the first cleaning residue and the dissolved residue.

In this example, it can be seen that the co'a degree increases with time, while the Cu concentration decreases and the pH also increases. The dissolution rate of Co was 87%.

The dissolution rate of Cu was 13%.

(Table 4) (Example 3) Put the solution 2i obtained in the cobalt dissolution process into a glass beaker, adjust the pH with sulfuric acid and heat it to 50 to 60°C, then add sodium sulfide and sulfuric acid. A cleaning treatment was performed to obtain a cleaning solution.

Furthermore, soda ash was added to this cleaning solution to adjust the final pH to 8, and the solution was filtered to obtain cobalt carbonate.

Table 5 shows the results of six tests conducted at different cleaning pHs. In this example, cleaning results in a certain amount of Co loss and a decrease in the collection rate, but the It was found that the Co content was significantly improved, and considering both of these factors, it was found that the lower the initial pH of the cleaning treatment, the better.

(Table 5) <Application example> (Application example 1) The cleaning solution obtained in the cleaning process shown in Fig. 1 was treated with an additional organic solvent according to Fig. 4, and zinc (Zn),
Cobalt powder can be recovered by removing impurities such as nickel (Ni) and recovering cobalt oxalate, and then thermally decomposing the cobalt oxalate in a hydrogen gas stream. By carrying out this treatment, it is possible to obtain cobalt powder having an average particle size of about 1 μm and a component ratio as shown in Table 6, for example.

(Table 6) (Application example 2) The dissolution residue obtained in the cobalt dissolution process shown in Fig. 1 is treated and dissolved with caustic soda according to Fig. 5, and then -
The solution is separated into a dissolved solution and a dissolved residue. The resulting melted residue has a higher copper grade than the melted residue obtained in the cobalt melting process shown in FIG. 1, and can be used as a more advantageous raw material for copper smelting. Furthermore, by subjecting the solution to the treatment shown in FIG. 5, ^S can also be recovered as arsenous acid.

300 g of the dissolution residue obtained in the above cobalt dissolution step was slurried with 1.5 J of water, and twice the theoretical amount of As contained in caustic soda was added thereto and treated at 80 to 90° C. for 4 hours. As a result, A of the dissolved residue obtained by washing with water and filtration.
The S grade was about 2%, and the Cu grade was over 60%. Also,
The grade of arsenous acid recovered according to Figure 5 is 99.
exceeded %.

<Effects of the Invention> According to the present invention, cobalt carbonate can be recovered at low cost by an extremely simple method from the clean residue obtained from zinc smelting. Furthermore, high-grade copper smelting raw materials can also be obtained during the cobalt carbonate recovery process.

[Brief explanation of the drawing]

Figure 1 is a system diagram of the present invention, Figure 2 is Co by PR,
A graph showing changes in the dissolution rate of Cu and ^S, Figure 3 is a graph showing changes over time in Co and Cu concentrations in the solution, and PH, and Figures 4 and 5 are systems of application examples of the present invention, respectively. figure,
FIG. 6 is a system diagram of zinc smelting, and FIG. 7 is a system diagram of a cleaning process in zinc smelting.

Claims (1)

[Claims] In addition to Co, mainly Cu, Zn, and C are obtained in the zinc smelting process.
d. Add water and sulfuric acid to the clean residue containing As, and remove mainly Zn.
A pickling solution containing Co is separated to produce a pickling residue containing Co, and by adding water and sulfuric acid to the pickling residue and further blowing air, a dissolved residue mainly containing Cu is separated. to generate a solution containing Co, and by adding hydrogen sulfide gas to the solution, a cleaning residue mainly containing sulfides of As, Cd, and Cu is separated to generate a cleaning solution containing Co, A method for recovering cobalt carbonate in a zinc smelting process, the method comprising recovering cobalt carbonate by adding soda ash to the cleaning liquid and filtering it.