Chromium residue wet detoxification method with improved detoxification effect

A technology of wet detoxification and process method, which is applied in the direction of protection devices against harmful chemicals, etc., which can solve the problems of rebound and substandard treatment, shorten the time of wet detoxification, and incomplete wet detoxification treatment, and achieve convenient operation, Low production cost and light rebound effect

Inactive Publication Date: 2019-11-05
CHANGCHUN GOLD RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the above problems, the present invention provides a chromium slag wet detoxification process that improves the detoxification effect. Aiming at the characteristics of high content of hexavalent chromium in chromium slag, two kinds of reducing agents are used respectively to remove the wa

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] The above-mentioned chromium slag sample is operated according to the following steps:

[0032] Step 1. Grinding and grading operations:

[0033] Grind the chromium slag to a fineness of -0.074mm and the mass percentage is 80%, add water to adjust the slurry, so that the liquid-solid ratio in the slurry is 4:1;

[0034] Step 2, reduction of water-soluble hexavalent chromium:

[0035] Put the adjusted pulp into the mixing tank, and at the same time add ferrous chloride as a reducing agent, the dosage is 50kg / t pulp, and the reaction time is 1h, to reduce the water-soluble hexavalent chromium in the pulp to trivalent chromium;

[0036] Step 3, reduction of acid-soluble hexavalent chromium:

[0037] Add concentrated sulfuric acid with a mass fraction of 98% to the pulp treated in step 2, the dosage is 550kg / t pulp, and the action time is 6h to keep the pH value of the pulp at 5.0, then add ferrous sulfate as a reducing agent, the dosage The pulp is 260kg / t, and the redu...

Embodiment 2

[0045] The above-mentioned chromium slag sample is operated according to the following steps:

[0046] Step 1. Grinding and grading operations:

[0047] Grind the chromium slag until the fineness-0.074mm mass percentage is 95%, add water to adjust the slurry, so that the liquid-solid ratio in the slurry is 6:1;

[0048] Step 2, reduction of water-soluble hexavalent chromium:

[0049] Add the adjusted ore pulp into the mixing tank, and at the same time add ferrous chloride as a reducing agent, the dosage is 60kg / t of ore pulp, and the reaction time is 1.5h, to reduce the water-soluble hexavalent chromium in the ore pulp to trivalent chromium;

[0050] Step 3, reduction of acid-soluble hexavalent chromium:

[0051] Add concentrated sulfuric acid with a mass fraction of 98% to the pulp treated in step 2, the dosage is 500kg / t pulp, and the action time is 4h, so that the pH value of the pulp is kept at 4.8, and then ferrous sulfate is added as a reducing agent. The pulp is 200k...

Embodiment 3

[0059] The above-mentioned chromium slag sample is operated according to the following steps:

[0060] Step 1. Grinding and grading operations:

[0061]Grind the chromium slag until the fineness-0.074mm mass percentage is 100%, add water to adjust the slurry, so that the liquid-solid ratio in the slurry is 8:1;

[0062] Step 2, reduction of water-soluble hexavalent chromium:

[0063] Put the adjusted pulp into the mixing tank, and at the same time add ferrous chloride as a reducing agent, the dosage is 100kg / t pulp, the reaction time is 4h, and the water-soluble hexavalent chromium in the pulp is reduced to trivalent chromium;

[0064] Step 3, reduction of acid-soluble hexavalent chromium:

[0065] Add concentrated sulfuric acid with a mass fraction of 98% to the pulp treated in step 2, the dosage is 700kg / t pulp, and the action time is 10h to keep the pH value of the pulp at 4.5, then add ferrous sulfate as a reducing agent, the dosage The pulp is 300kg / t, and the reductio...

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PUM

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Abstract

The invention belongs to the technical field of wet detoxification methods, and particularly relates to a chromium residue wet detoxification method with an improved detoxification effect. Two reducing agents which are ferrous chloride and ferrous sulfate are used to respectively reduce water-soluble and acid-soluble hexavalent chromium in chromium residues, so the content of the hexavalent chromium in the chromium residues is reduced, the wet detoxification time is shortened, and the problems of incompletion, subsequent rebounding and non-compliant treatment of existing wet detoxification treatments are solved.

Description

technical field [0001] The invention belongs to the technical field of wet detoxification process, in particular to a chromium slag wet detoxification process for improving detoxification effect. Background technique [0002] Chromium slag is a solid toxic waste produced in the process of roasting and producing chromium salts. Its main components are oxides or alkaline compound salts of chromium, iron, aluminum, calcium, magnesium, and silicon. and water solubility. Metallic chromium and trivalent chromium are harmless to the human body. Hexavalent chromium is divided into water-soluble hexavalent chromium and acid-soluble hexavalent chromium. Among them, water-soluble hexavalent chromium is mainly composed of sodium chromate tetrahydrate, calcium chromate, calcium chromoaluminate and alkali Soluble hexavalent chromium can cause varying degrees of damage to human skin, respiratory tract, eyes and gastrointestinal tract; acid-soluble hexavalent chromium mainly consists of di...

Claims

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Application Information

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IPC IPC(8): A62D3/37
CPCA62D3/37
Inventor 孙洪丽岳辉郑晔郝福来杨海鸣
Owner CHANGCHUN GOLD RES INST
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