A method for removing cadmium

A copper-cadmium slag and high-grade technology, which is applied in the field of wet zinc smelting, can solve problems such as excessive consumption of zinc powder, poor purification and removal of cadmium, and imbalanced ratio of copper and cadmium to achieve the problem of imbalanced copper-cadmium ratio and copper-cadmium slag ratio. The effect of reducing and increasing the recovery rate

Active Publication Date: 2015-11-25
BAIYIN NONFERROUS GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for removing cadmium in order to solve the problems that the proportion of copper and cadmium in the supernatant liquid in the hydrometallurgy leaching is seriously out of balance, the effect of purifying and removing cadmium is poor, and the consumption of zinc powder is high.

Method used

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  • A method for removing cadmium

Examples

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Effect test

Embodiment 1

[0028] (1) One-stage purification and pre-removal of copper

[0029] In copper 1.3kg / m 3 , containing cadmium 0.4kg / m 3 Add 80 mesh 2.4kg / m 3 The coarse zinc powder pre-removes copper until the ratio of copper ions to cadmium ions in the liquid is 1:3.5, and the copper-cadmium slag and pre-removal of copper containing 33% copper and 2.5% cadmium are obtained by filtration. filtrate.

[0030] (2) One-stage purification to remove copper and cadmium

[0031] in step Add 200 mesh 0.8kg / m to the obtained pre-copper removal filtrate 3 The blown zinc powder continues to remove copper and cadmium, and after filtration, copper cadmium slag with a copper content of 4.8% and a cadmium content of 16.7% is obtained. Copper cadmium slag with a high cadmium grade and a section of filtrate are obtained. The slag and leachate are replaced once to obtain cadmium cotton and the replacement filtrate, and the cadmium cotton is pressed to obtain cadmium ingots, and the replacement filtrate i...

Embodiment 2

[0040] (1) One-stage purification and pre-removal of copper

[0041] In copper 0.4kg / m 3 , containing cadmium 0.8kg / m 3 Add 0.3kg / m of 60 mesh Zhanzhong supernatant to the supernatant 3 The coarse zinc powder pre-removes copper until the ratio of copper ions to cadmium ions in the supernatant is 1:2.5, and the copper-cadmium slag and the pre-copper cadmium slag with a copper mass fraction of 28% and a cadmium content of 9.7% are obtained by filtering. Decopper filtrate.

[0042] (2) One-stage purification to remove copper and cadmium

[0043] in step Add 150 mesh 1.6kg / m to the obtained pre-copper removal filtrate 3 The blown zinc powder continues to remove copper and cadmium. After filtration, the copper-cadmium slag with a copper mass fraction of 5.3% and a cadmium content of 15.8% and a high-grade copper-cadmium slag and a filtrate are obtained. The obtained copper-cadmium slag is leached, Filter to obtain copper slag and leaching solution, replace the leaching solut...

Embodiment 3

[0052] (1) One-stage purification and pre-removal of copper

[0053] In copper 0.6kg / m 3 , containing cadmium 0.6kg / m 3 First add 0.7kg / m of 80 mesh Zhanzhong supernatant to the supernatant 3 Pre-removal of copper with coarse zinc powder, until the ratio of copper ions to cadmium ions in the liquid is 1:3, and filter to obtain copper-cadmium slag with a copper content of 30% and a cadmium content of 6.5% and a copper-cadmium slag with a high copper grade and a low cadmium grade and pre-removal of copper filtrate.

[0054] (2) One-stage purification to remove copper and cadmium

[0055] in step Add 180 mesh 1.2kg / m to the obtained pre-copper removal filtrate 3 Blowing zinc powder continues to remove copper and cadmium, and after filtration, obtain a copper-cadmium slag with a copper mass percentage of 6.4% and a cadmium content of 16.1%. To obtain copper slag and leachate, replace the leachate once, obtain cadmium cotton and replace the filtrate, press the cadmium cotton...

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Abstract

The invention discloses a cadmium removal method comprising the steps: firstly, purifying and pre-removing copper; adding crude zinc powder according to the contents of copper and cadmium in a middle supernatant liquid to pre-remove copper until the ratio of copper ions to cadmium ions in the supernatant liquid is up to 1:3, and filtering to obtain copper and cadmium residues with a high copper grade and a low cadmium grade and a copper-removed solution; and adding blown zinc powder into the copper-pre-removed solution, then, continuing to remove copper and cadmium, and filtering to obtain copper and cadmium residues with a low copper grade and a high cadmium grade. By using the cadmium removal method, the problems of disproportionality of copper and cadmium in the middle supernatant liquid, poor cadmium removal effect, high zinc powder consumption and incapability of treating a large quantity of copper and cadmium residues generated when the grade of copper contained in a zinc concentrate is high are solved; in addition, the production efficiency is increased; and zinc dross is sufficiently utilized to prepare the crude zinc powder for pre-removing copper, so that the production cost is reduced, and the recovery rate of zinc powder is increased.

Description

technical field [0001] The invention relates to zinc hydrometallurgy, in particular to a method for removing cadmium in zinc hydrometallurgy. Background technique [0002] The supernatant in zinc hydrometallurgy leaching contains impurities such as copper, cadmium, cobalt, nickel, etc. These impurities exist in the solution in the form of sulfate, which are extremely harmful in the process of zinc electrowinning, so the purpose of purification is to remove This part of the impurities. Usually, zinc powder replacement method is used for purification, copper and cadmium are removed at low temperature, and cobalt and nickel are removed at high temperature. According to production experience, maintaining a certain amount of copper ions in the solution before purification can activate zinc powder, keep the surface of zinc powder fresh, and promote the replacement reaction. When the copper ion content is low, the cadmium removal effect is poor, but when the copper ion content is...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B3/46C22B19/00
CPCY02P10/234Y02P10/20
Inventor 马菲菲李志强杨斌刘向东冶玉花赵贵俊焦晓斌
Owner BAIYIN NONFERROUS GROUP
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