Two-stage deep wet detoxification method for industrial chromium slag

A technology of wet detoxification and chromium slag, which is applied in the protection device against harmful chemicals, etc., can solve the problems of rebound and inability to restore hexavalent chromium more thoroughly, and achieve the effect of avoiding the risk of rebound

Inactive Publication Date: 2020-02-21
CHANGCHUN GOLD RES INST
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The invention provides a two-stage deep wet detoxification method for industrial chromium slag, so as to solve the current problem that hexavalent chromium cannot be more thoroughly reduced, and there are a large number of signs of rebound after being buried for a certain period of time

Method used

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  • Two-stage deep wet detoxification method for industrial chromium slag

Examples

Experimental program
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Effect test

experiment example 1

[0018] Include the following steps:

[0019] (1) Grinding fineness of chrome slag ore -0.074mm%: 90;

[0020] (2) A stage of water immersion with a solid-to-liquid ratio of 6:1, a constant temperature water bath at 75°C, stirring at 90r / min for 1 hour;

[0021] (3) Solid-liquid separation obtains orange-red hexavalent chromium liquid;

[0022] (4) The solid enters the second-stage acid leaching, and the liquid is added with sodium metabisulfite until the liquid turns dark green;

[0023] (5) Calcium oxide is added to the dark green trivalent chromium liquid to form a gray-green chromium hydroxide precipitate, and the filtered clear liquid is used as backwater;

[0024] (6) The solid-liquid ratio of the second-stage acid leaching is 3:1, and the constant temperature water bath is 80°C;

[0025] (7) Add concentrated sulfuric acid, the consumption of concentrated sulfuric acid is 700kg / t, soak for 4 hours;

[0026] (8) adding excess ferrous sulfate to process for 4 hours;

...

experiment example 2

[0030] Include the following steps:

[0031] (1) Grinding fineness of chrome slag ore -0.074mm%: 90;

[0032] (2) One stage of water immersion with a solid-to-liquid ratio of 6:1, a constant temperature water bath at 80°C, stirring at 100r / min for 1.5 hours;

[0033] (3) Solid-liquid separation obtains orange-red hexavalent chromium liquid;

[0034] (4) The solid enters the second-stage acid leaching, and the liquid is added with sodium metabisulfite until the liquid turns dark green;

[0035] (5) Calcium oxide is added to the dark green trivalent chromium liquid to form a gray-green chromium hydroxide precipitate, and the filtered clear liquid is used as backwater;

[0036] (6) The solid-liquid ratio of the second-stage acid leaching is 3:1, and the constant temperature water bath is 85°C;

[0037] (7) Add concentrated sulfuric acid, the consumption of concentrated sulfuric acid is 720kg / t, soak for 5 hours;

[0038] (8) adding excess ferrous sulfate to process for 5 hour...

experiment example 3

[0042] Include the following steps:

[0043] (1) Grinding fineness of chrome slag ore -0.074mm%: 90;

[0044] (2) A stage of water immersion with a solid-to-liquid ratio of 6:1, a constant temperature water bath at 85°C, stirring at 110r / min for 2 hours;

[0045] (3) Solid-liquid separation obtains orange-red hexavalent chromium liquid;

[0046] (4) The solid enters the second-stage acid leaching, and the liquid is added with sodium metabisulfite until the liquid turns dark green;

[0047] (5) Calcium oxide is added to the dark green trivalent chromium liquid to form a gray-green chromium hydroxide precipitate, and the filtered clear liquid is used as backwater;

[0048] (6) The solid-liquid ratio of the second-stage acid leaching is 3:1, and the constant temperature water bath is 90°C;

[0049] (7) Add concentrated sulfuric acid, the consumption of concentrated sulfuric acid is 740kg / t, soak for 6 hours;

[0050] (8) adding excess ferrous sulfate to process for 6 hours; ...

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Abstract

The invention relates to a two-stage deep wet detoxification method for industrial chromium slag, and belongs to the field of treatment of industrial chromium slag. The grinding fineness of chromium slag ore is -0.074 mm%: 90; first stage water leaching solid-to-liquid ratio is 6: 1, constant-temperature water bath is carried out at 75-85 DEG C, and stirring is carried out for 1-2 hours at the speed of 90-110r / min; solid-liquid separation is carried out to obtain an orange red hexavalent chromium liquid; an obtained solid is subjected to second stage acid leaching, and sodium metabisulfite isadded into an obtained liquid until the liquid becomes dark green; calcium oxide is added into the dark green trivalent chromium liquid to form grey green chromium hydroxide precipitate, and a clearliquid obtained through filtering is recycled as return water; wherein the second stage acid leaching solid-to-liquid ratio is 3: 1, and constant-temperature water bath is carried out at 80-90 DEG C;concentrated sulfuric acid is added, the dosage of the concentrated sulfuric acid is 700-740 kg / t, and soaking is conducted for 4-6 h; excessive ferrous sulfate is added for treating for 4-6 hours; calcium oxide is added to adjust the pH value of an obtained slag slurry to be greater than 6; ore washing is conducted, washing water is recycled as return water, and waste residues are filtered and discharged. According to the two-stage deep wet detoxification method, the indexes after treatment are far lower than those in the national chromium slag landfill standards, the standard of first-time treatment landfill is achieved, the rebound risk is avoided, and the harm of chromium slag discharge treatment landfill to the environment is fundamentally avoided.

Description

technical field [0001] The invention relates to a deep wet detoxification method for chromium slag produced by industrial production of metal chromium and chromium salts and the rebound slag of the chromium slag after treatment. Background technique [0002] The in-depth treatment of chromium slag has always been an environmental protection problem. Currently, there are more than 20 provinces and cities in China that discharge chromium slag. When there is no reducing agent in chromium slag, the aqueous solution of sodium dichromate contained in it contains highly toxic dichromate radicals containing hexavalent chromium, which will greatly damage the environment and the life safety of humans and animals. The traditional wet detoxification method has certain limitations, and cannot restore hexavalent chromium more thoroughly, and there are a lot of signs of rebound after a certain period of time. Contents of the invention [0003] The invention provides a two-stage deep wet...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): A62D3/35A62D3/36
CPCA62D3/35A62D3/36
Inventor 杨海鸣孙洪丽岳辉郝福来蒋雨仑
Owner CHANGCHUN GOLD RES INST
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