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The treatment method of chromium residue

A treatment method and technology of chromium slag, applied in the direction of improvement of process efficiency, etc., can solve problems such as unfavorable operation, increase of treatment cost, large amount of waste liquid, etc., to prevent re-oxidation and leaching, reduce detoxification process, and save treatment cost Effect

Inactive Publication Date: 2014-10-29
GUIYANG ZHONGKE RONGSHI NEW MATERIAL TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] However, when the ferrous sulfate method is used to treat chromium slag, the amount of ferrous sulfate added is relatively large, and the amount of waste liquid generated is relatively large, which not only increases the treatment cost, but also is not conducive to specific operations.
[0011] The leaching-exchange method is also a method for wet treatment of chromium slag. Firstly, the chromium slag is ground into powder, then water is added, and CO is introduced while stirring. 2 The gas is used as the leaching agent to extract the chromium slag, and then the hexavalent chromium ions in the leach solution are recovered by ion exchange, thereby removing the hexavalent chromium ions in the chromium slag, and the removal rate can reach 96.7%; at the same time, this method adds BaCl 2 Fix the residual hexavalent chromium ions in the chromium slag after leaching, but the water-soluble hexavalent chromium in the chromium slag after treatment is still more than 100mg / kg, which does not meet the discharge standard of solid waste

Method used

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  • The treatment method of chromium residue

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0080] Provide the chromium slag of chemical composition as shown in table 1;

[0081] At room temperature of 20°C, add 5kg of the chromium slag and 2kg of water into a ball mill for ball milling for 20 minutes, add 8kg of water to adjust the concentration to 20%, and then separate through a hydrocyclone. After separation, the slurry below 150μm enters a plate and frame filter press Press filtration for dehydration, wash with water for 10 minutes under stirring conditions, and press filtration for dehydration again to obtain chromium slag slurry;

[0082] Remove impurities and dry the rice straw so that its moisture content is 18%, and then send it to the carbonization furnace for treatment. The temperature of the carbonization furnace is controlled at 250°C, and the temperature of the smoke is 80°C. After the exhausted smoke is condensed to 15°C, the pH value is obtained. Rice vinegar with a value of 2; 1L of rice vinegar is mixed with 6L of water to obtain an aqueous solutio...

Embodiment 2

[0088] Provide the chromium slag of chemical composition as shown in table 1;

[0089] At room temperature of 20°C, add 5kg of the chromium slag and 2kg of water into a ball mill for ball milling for 30 minutes, add 8kg of water to adjust the concentration to 20%, and then separate through a hydrocyclone. After separation, the slurry below 100μm enters a plate and frame filter press Press filtration for dehydration, wash with water for 20 minutes under agitation, and press filtration for dehydration again to obtain chromium slag slurry;

[0090] Remove impurities and dry the rice straw so that its moisture content is 15%, and then send it to the carbonization furnace for treatment. The temperature of the carbonization furnace is controlled at 300°C, and the temperature of the smoke is 100°C. After the exhausted flue gas is condensed to 25°C, the pH value is obtained. Rice vinegar with a value of 3; 1L of rice vinegar is mixed with 8L of water to obtain an aqueous solution of r...

Embodiment 3

[0096] Provide the chromium slag of chemical composition as shown in table 1;

[0097] At room temperature of 20°C, add 5kg of the chromium slag and 2kg of water into a ball mill for ball milling for 40 minutes, add 8kg of water to adjust the concentration to 20%, and then separate through a hydrocyclone. After separation, the slurry below 120μm enters a plate and frame filter press Press filtration for dehydration, wash with water for 30 minutes under agitation, and press filtration for dehydration again to obtain chromium slag slurry;

[0098] Remove impurities and dry the rice straw so that its moisture content is 19%, and then send it to the carbonization furnace for treatment. The temperature of the carbonization furnace is controlled at 400°C, and the temperature of the smoke is 130°C. After the exhausted smoke is condensed to 30°C, the pH value is obtained. Rice vinegar with a value of 2.5; 1L of rice vinegar is mixed with 6L of water to obtain an aqueous solution of ri...

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Abstract

The invention provides a chromium slag treatment method. The chromium slag treatment method comprises the following steps of: (a) carrying out digestion treatment on chromium slag slurry, then carrying out solid-liquid separation to obtain filtrate and filter residue; and (b) mixing the filter residue obtained in the step (a) with a curing agent, then carrying out curing treatment, wherein the curing agent comprises potassium chloride, sodium chloride, potassium dihydrogen phosphate, sodium sulfite, aluminium potassium sulfate, calcium chloride and magnesium chloride. According to the chromium slag treatment method, when the curing agent comprising potassium chloride, sodium chloride, potassium dihydrogen phosphate, sodium sulfite, aluminium potassium sulfate, calcium chloride and magnesium chloride is used for carrying out curing treatment on the filter residue, physical and chemical reactions happen between filer residue particles to produce calcium-vanadium crystals, so that the filter residue stably exists, thus the reoxidation and leaching of the filter residues can be effectively avoided, so that chromium slag meets the emission standard and has good stability.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment, and in particular relates to a treatment method for chromium slag. Background technique [0002] Chromium slag is an industrial waste produced during the production of metallic chromium and chromium salts, mainly containing Cr 2 o 3 , CaO, MgO, Fe 2 o 3 Among them, hexavalent chromium is a strong carcinogen, which will not only pollute the environment but also affect human health. Therefore, it is necessary to treat the chromium slag to make it harmless. [0003] At present, there are two main ways to deal with chromium slag: one is to use fire method to convert hexavalent chromium into stable and less toxic trivalent chromium; the other is to use wet method to convert water-soluble and Acid-soluble hexavalent chromium is dissolved, and a reducing agent is added to reduce it to trivalent chromium. Among them, the fire treatment has the problems of high cost and easy secondary p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/04C22B3/04C22B34/32
CPCY02P10/20
Inventor 陈国强徐江蒋小涛肖唐付陈国胜蒋毅
Owner GUIYANG ZHONGKE RONGSHI NEW MATERIAL TECH