CN1202461A

CN1202461A - Process for producing three basic lead sulphate using lead in copper slime

Info

Publication number: CN1202461A
Application number: CN 97105925
Authority: CN
Inventors: 王卫亭; 孙林权
Original assignee: PENGHUI COPPER INDUSTRY Co Ltd YANTAI
Current assignee: PENGHUI COPPER INDUSTRY Co Ltd YANTAI
Priority date: 1997-06-13
Filing date: 1997-06-13
Publication date: 1998-12-23

Abstract

The technological features of the present invention is that during the wet process of extracting Au and Ag from slime, lead sulfate produced is synthesized into three basic sulfate by adding caustic soda. The present invention can raise economic utility and reduce environmental pollution through recovering lead in slime.

Description

Method for producing tribasic lead sulfate by using lead in copper anode slime

The invention relates to a method for producing tribasic lead sulfate, in particular to a method for producing tribasic lead sulfate by utilizing lead in copper anode slime and a product.

In the background art, copper anode slime is a main raw material for producing gold and silver, and contains 20-45% of valuable metal lead. At present, the method for producing gold and silver by using copper anode slime comprises a fire method and a wet method. The pyrogenic process treatment is that after copper anode slime is roasted and decoppered, lead in the slag and gold and silver are smelted together in a converter, so that noble lead is obtained and then blown and oxidized to obtain a gold and silver alloy, and the lead is completely volatilized in a lead oxide state in the blowing and oxidizing process. Obviously, the method not only wastes valuable metal lead in the anode mud, but also seriously pollutes the atmospheric environment by the discharged lead oxide. Wet processing is divided into two methods, namely lead removal and lead non-removal: the method without lead removal is that the slag obtained after the gold and silver are produced by decoppering anode slime contains a small amount of gold and silver (lead is all in the slag), the slag is returned to a copper smelting system or is treated by a converter (the same as a pyrogenic process), the method for removing lead is that lead is treated by a wet method to obtain lead sulfate or lead sulfide, and the product has low industrial value and is mainly used as a raw material for producing lead.

The invention aims to provide a method for producing tribasic lead sulfate by using lead in copper anode slime, which solves the defects of lead waste, environmental pollution and low industrial value of a finished product in the background technology.

The technical scheme of the invention is realized as follows: a method for producing tribasic lead sulfate by using lead in anode slime comprises the first step of adding sulfuric acid into the anode slime for slurrying, the second step of removing copper to produce liquid A and slag A, the third step of adding soda into the slag A to be converted into liquid B and slag B, the fourth step of adding nitric acid with the concentration of 1N into the slag B according to the solid-liquid ratio of 1: 3 at normal temperature for lead separation to produce liquid C and slag C, and the fifth step of adding a proper amount of sulfuric acid into the liquid C for lead precipitation to produce liquid C and lead sulfate, wherein the sixth step of adding 20% caustic soda into the lead sulfate according to the solid-liquid ratio of 1: 3-5 at normal temperature until the pH value is 9, stirring for more than 40 minutes, washing to be neutral after the reaction is finished, and drying at the temperature of 115 ℃ and 125 ℃ to obtain the finished product of tribasic lead sulfate. Wherein the solid-liquid ratio in the sixth step is preferably 1: 3, and the chemical equation of the reaction in each step is as follows:

compared with the background technology, the invention has the advantages and effects that: firstly, the waste gas pollution and the white waste of valuable metal lead generated in the process of extracting gold and silver from anode mud by a fire method are avoided. Secondly, the defect of low industrial value of the product obtained after lead is removed in the wet method extraction process of gold and silver from anode mud is overcome.

The drawings of the invention are illustrated as follows:

figure 1 is a process flow diagram of the present invention,

fig. 2 is a flow chart of a conventional wet process.

The invention is further illustrated by the following examples:

example 1: referring to fig. 1, firstly, adding sulfuric acid into anode mud for slurrying, secondly, producing liquid A and slag A through decoppering treatment, wherein the liquid A is replaced to obtain copper powder, thirdly, adding soda ash into the slag A to be converted into liquid B and slag B, wherein the liquid B is neutralized and then discharged, fourthly, adding nitric acid with the concentration of 1N into the slag B according to the solid-to-liquid ratio of 1: 3 at normal temperature for lead separation to produce liquid C and slag C, wherein the slag C is used for producing gold and silver, fifthly, adding a proper amount of sulfuric acid into the liquid C for lead precipitation to produce liquid D and lead sulfate, wherein the liquid D returns to the lead separation process, sixthly, adding 20% caustic soda into the lead sulfate according to the solid-to-liquid ratio of 1: 3 until the pH is 9, stirring for more than 40 minutes, washing to neutrality after the reaction is finished product, drying at 120 ℃ to obtain tribasic lead sulfate, and finally crushing, and bagging to obtain the qualified industrial product. The method not only avoids environmental pollution, but also greatly improves the industrial value of the finished product.

Example 2 acceptable lead sulfate tribasic was also obtained by adjusting the solid to liquid ratio in the sixth step to 1: 4 according to the procedure described in example 1.

Claims

1. A method for producing tribasic lead sulfate by using lead in anode slime comprises the first step of adding sulfuric acid into the anode slime for slurrying, the second step of removing copper to produce liquid A and slag A, the third step of adding soda into the slag A to be converted into liquid B and slag B, the fourth step of adding nitric acid with the concentration of 1N into the slag B according to the solid-liquid ratio of 1: 3 at normal temperature for lead separation to produce liquid C and slag C, and the fifth step of adding sulfuric acid into the liquid C for lead precipitation to produce liquid D and lead sulfate, and is characterized in that the sixth step of adding caustic soda with the concentration of 20% into the lead sulfate according to the solid-liquid ratio of 1: 3-5 at normal temperature until the pH is 9, stirring for more than 40 minutes, washing to be neutral after the reaction is finished, and drying at the temperature of 115-125 ℃ to obtain the tribasic lead sulfate.

2. The method for producing lead sulfate tribasic according to claim 1, characterized in that the solid-to-liquid ratio in the sixth step is 1: 3.