JPH0762454A - Recovering method of silver concentrate high in silver content - Google Patents

Abstract

PURPOSE:To recover a silver concentrate high in silver content and to improve actual yield by adding the specified amount of a specified alkyl sodium sulfate as the capturing agent for flotation to the sulfuric acid treated slag generating at a wet zinc smelting. CONSTITUTION:A zinc concentrate is calcined, and the calcined ore is leached by an electrolysis waste liq., and after washing leach, the leach is electrolyzed to recover an electrolytic zinc. The leached slag generating at above wet zinc smelting method is treated with a high temp. and high concn. sulfuric acid to remove the oxides of Zn and Fe. On the other hand, the sulfuric acid treated slag is subjected to flotation treatment to recover the silver concentrate. 20-120g/t alkyl sodium sulfate having a carbon number of 8-20 is added to the sulfuric acid treated slag as the capturing agent. In this way, the silver concentrate having high silver content is recovered as a froth. Silver is removed from the silver concentrate in high actual yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a silver concentrate having a high Ag content from a leach slag generated by a hydrozinc smelting method.

[0002]

2. Description of the Related Art It is well known that a hydrozinc smelting method is generally performed according to the flow chart shown in FIG. That is, after leaching a roasted ore mainly consisting of zinc oxide produced by oxidizing and roasting a zinc concentrate as a raw material with an electrolytic waste liquid generated in an electrolysis step described below, the leachate is purified and then electrolyzed in the liquid. Is recovered as electric zinc. On the other hand, the leach slag mainly composed of zinc ferrite separated from the leachate in the leach step is Zn, Fe, Pb,
In order to recover Ag and the like, a method of treating under high temperature and high acid conditions (for example, hematite method) is performed, but this method first removes Zn and Fe in the leach slag by a sulfuric acid solution of high concentration at high temperature. After melting, Zn is returned to zinc smelting as an aqueous solution of zinc sulfate, Fe is sent to a cement factory as a raw material for cement, and a sulfuric acid treatment slag (hereinafter referred to as "residue") is subjected to a flotation treatment to recover a silver concentrate. Yes, and this method is well known.

Further, as a method for recovering the silver concentrate in the residue by flotation, for example, JP-A-51-3371 is used.
The method described in No. 9 is known, and in this method, a xanthogen sun salt, dithiophosphate, or the like is used as a collector.

[0004]

However, since the Ag contained in the above residue is derived from the zinc concentrate used as the raw material for zinc smelting, the content of Ag depends on the amount of Ag and impurities in the raw zinc concentrate. Although it fluctuates greatly, Ag of raw material zinc concentrate to be processed by zinc smelting with the closing of a domestic mine that has been producing zinc ore with high Ag content in recent years
Since the content rate has decreased, the Ag content rate in the above residue has decreased to 0.05 to 0.1%. When the above-mentioned conventional method is used, the Ag content of the silver concentrate is only 0.2 to 0.4%, and therefore, the actual Ag yield cannot be increased in the subsequent lead smelting. Therefore, it is required to further increase the Ag content of the silver concentrate.

[0005]

[Means for Solving the Problems] Therefore, the present inventors have conducted a study to obtain a silver concentrate having a high Ag content from the above residue, and as a result, have been used as a collector in a conventional silver concentrate recovery method. Higher A was obtained when sodium alkylsulfate was used in place of the existing xanthogen sun salt or dithiophosphate.
g concentrate silver concentrate (Ag content of 0.6 to 0.9
%) Can be obtained. Therefore, the present invention was made based on the above-mentioned research results, and from the residue after the oxides of Zn and Fe were removed from the leach slag generated in the hydrozinc smelting method using sulfuric acid, the silver refinement was carried out by flotation. In the method for recovering ore, the high Ag-containing silver concentrate is added to the flotation of the silver concentrate by adding sodium alkylsulfate having 8 to 20 carbon atoms as a collector at a rate of 20 to 120 g / t with respect to the residue. It is characterized by the method of recovering.

In the method of the present invention, the amount of sodium alkylsulfate added is 20 to 120 g / t. When the amount added is less than 20 g / t, high Ag recovery cannot be achieved, while the addition thereof The amount is 120g / t
The reason for this is that if it exceeds the above range, co-flotation of other components such as lead sulfate will start and the desired high Ag content cannot be obtained.

Further, the reason why the carbon number is limited to 8 to 20 is that Ag does not reach the desired recovery rate when the carbon number of the alkyl group of the scavenger is less than 8 and exceeds 20 in the slurry. This is because the dispersibility of the collector is deteriorated.

[0008]

EXAMPLES Next, the method of the present invention will be specifically described by way of examples. First, three types of residue obtained by treating the leach slag discharged from the zinc smelter by the hematite method were prepared. Each of these residues had the Ag content shown in Table 1. Water is added to this residue to repulp it to prepare a slurry having a solid-liquid ratio of 20%, and the collector shown in Table 1 is added thereto at the same ratio as shown in Table 1, and the flotation machine is used to add the collector. The method of the present invention 1 to
3 and conventional methods 1 to 3 were carried out. The analytical value of Ag in the silver concentrate obtained as floss was measured. The results of these measurements are shown in Table 1.

[0009]

[Table 1]

Incidentally, the collectors kalibutyl xanthate and kaliamil xanthate in the conventional methods 1 to 3 are one of the xanthogen sun salts, and MIBC (methylisobutylcarbinol) is added as a foaming agent. .

[0011]

From the results shown in Table 1, the method 1 of the present invention
It is clear that according to No. 3, silver concentrate having a much higher Ag content than the conventional methods 1 to 3 can be recovered. As described above, according to the method of the present invention, silver concentrate having a high Ag content can be recovered, so that it is possible to recover Ag at a high actual yield in the lead smelting in the next step, which is an industrial contribution. Is big.

[Brief description of drawings]

FIG. 1 is an example of a flow chart showing a flotation process of a sulfuric acid treatment slag in wet zinc smelting.

Claims (1)

[Claims] 1. A method for recovering silver concentrate by flotation from a sulfuric acid-treated slag obtained by removing oxides of Zn and Fe from sulfuric acid by sulfuric acid from a leaching slag generated in a hydrozinc smelting method. A method for recovering a high Ag-containing silver concentrate, comprising adding sodium alkylsulfate having 8 to 20 carbon atoms to a sulfuric acid-treated slag in an amount of 20 to 120 g / t as a collector used for flotation of the concentrate.