Method for producing chromic oxide by using sludge of containing chrome

A technology of chromium trioxide and chromium sludge, which is applied in the directions of chromium trioxide, chromium oxide/hydrate, chemical instruments and methods, etc., to achieve the effects of high profit, convenient operation and quick effect.

Inactive Publication Date: 2005-11-16
高志远
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some progress has been made in the utilization of sludge containing chromium hydroxide, such as making magnetic materials, tanning agents, catalysts, polishing pastes, coating materials, etc., but there is still the possibility of further development and utilization

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Production of chromium trioxide from chromium-containing sludge:

[0013] (1) drying or drying the chromium-containing sludge;

[0014] (2) Put the dry chromium-containing sludge into the roasting furnace for roasting, the roasting temperature is 800-1000°C, and the roasting time is 5-6 hours, until the chromium hydroxide in the chromium-containing sludge is completely converted into dichromium trioxide, and dichromium trioxide is obtained. Chromium crude products;

[0015] (3) Take the crude chromium trioxide out of the furnace and put it into the cleaning tank to cool down. After cooling down to about 80°C, add 70-90°C hot water to wash, heat the water while stirring, and wait for the stirring to be even. The water-soluble matter in the crude product is dissolved in water, and chromium trioxide is precipitated. Suck off the upper aqueous solution, sieve the chromium trioxide precipitate to remove impurities, and rinse with hot water while sieving to remove impuritie...

Embodiment 2

[0018] Production of chromium trioxide from chromium-containing sludge:

[0019] (1) Wash the chromium-containing sludge to remove impurities;

[0020] (2) dewatering with a filter press;

[0021] (3) drying or drying the chromium-containing sludge;

[0022] (4) Put the dried chromium-containing sludge into the roasting furnace for roasting, the roasting temperature is 800-1000°C, and the roasting time is 5-6 hours, until the chromium hydroxide is completely converted into dichromium trioxide, and crude dichromium trioxide is obtained after being released from the furnace ;

[0023] (5) Rinse the crude chromium trioxide with hot water three times to remove water-soluble matter to obtain a precipitate of chromium trioxide. Dry and dehydrate with a centrifuge;

[0024] (6) drying the chromium sesquioxide after drying, and then grinding and sieving to obtain refined chromium sesquioxide products of different meshes.

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PUM

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Abstract

A process for preparing Cr2O3 from the Cr contained sludge includes water washing, press filtering for dewatering, drying, calcining to obtain coarse Cr2O3 product, removing the water-soluble impurities by use of hot water, centrifugal drying, baking, grinding and sieving.

Description

technical field [0001] The invention relates to a production method of chromium trioxide, that is, a method for producing chromium trioxide by using chromium hydroxide in chromium-containing sludge. Background technique [0002] At present, domestic electroplating wastewater treatment basically produces chromium-containing sludge. This chromium-containing sludge is a kind of waste residue, which needs to be treated by chemical or physical methods, otherwise it will cause secondary pollution. Some progress has been made in the utilization of sludge containing chromium hydroxide, such as making magnetic materials, tanning agents, catalysts, polishing pastes, paint raw materials, etc., but there is still the possibility of further development and utilization. Contents of the invention [0003] The present invention provides a method for producing chromium trioxide by using electroplating sludge containing chromium hydroxide. The present invention utilizes the electroplating ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G37/033
Inventor 崔国英高志远
Owner 高志远
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