Method for recycling traditional chromium residue

A recycling and chromium slag technology, applied in the field of traditional chromium slag recycling, can solve the problems of high cost, small processing capacity and low efficiency

Inactive Publication Date: 2011-09-21
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

These methods have many shortcomings such as incomplete detoxification, high cost, s...

Method used

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  • Method for recycling traditional chromium residue
  • Method for recycling traditional chromium residue
  • Method for recycling traditional chromium residue

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0060] See figure 2 , the device is a schematic diagram of the main reaction device for leaching traditional chromium slag with ammonium chloride. The main component is an electric heating pressure reactor 7 (made of stainless steel, with an effective volume of 2L, the lid of which is detachable, fastened by bolts, and can be sealed to withstand the highest pressure. 10MPa).

[0061] On the outside of the lid of the electric heating pressure reaction kettle 7, a pressure gauge 9 is installed to show the pressure in the kettle; a thermocouple inserted into the bottom of the electric heating pressure reaction kettle to control the temperature in the electric heating pressure reaction kettle 11. It is connected to the program temperature controller 12 connected to the power supply outside the electric heating pressure reactor; a stirring blade 8 is arranged at the center of the inner bottom of the electric heating pressure reactor, and the stirring blade is connected to the elec...

Embodiment 2

[0075] Adopt the method and device of embodiment 1, just different reaction conditions are:

[0076] 1. Ammonium chloride leaching:

[0077] Weigh 100g of traditional chromium slag (passed through a 100-mesh sieve after being crushed and ground, and the composition is shown in Table 1), weigh 240g of ammonium chloride and 20g of ferrous chloride tetrahydrate, and measure 445ml of deionized water.

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Abstract

The invention relates to a method for recycling traditional chromium residue, in particular to a method for recycling the traditional chromium residue by replacing strong acid (hydrochloric acid or sulfuric acid) with an ammonium salt (ammonium chloride or ammonium sulfate) of the strong acid. In the method, chromium residue generated in the traditional calcium roasting production process for sodium bichromate is taken as a treatment object, ammonium salts (including ammonium chloride and ammonium sulfate) of the strong acid and reducing ferrous salts (including ferrous chloride and ferrous sulfate) are adopted to make calcium, magnesium, sodium, chromium and the like in the chromium residue form soluble chloride or sulfate, then the calcium, the magnesium and the chromium are precipitated by utilizing ammonia released by decomposing the ammonium salts and adding carbon dioxide, and are returned to the calcium roasting production process for the sodium bichromate to realize the circulation, ammonium chloride and ammonium sulfate regenerated by reacting with the chloride and the sulfate are recycled, and final slag is used as a raw material of cement after the treatment. In the method, the strong acid is not added, so the requirements on equipment materials are reduced; and the recycling of elements such as calcium, magnesium, chromium and the like greatly reduces the amount of the final slag, and greatly improves the utilization rate of traditional chromium residue raw materials.

Description

technical field [0001] The invention relates to a method for recycling traditional chromium slag, in particular to a method for recycling traditional chromium slag by using strong acid ammonium salt (ammonium chloride or ammonium sulfate) instead of strong acid (hydrochloric acid or sulfuric acid). technical background [0002] Traditional chromium slag refers to the chromium-containing waste slag produced during the production process of traditional red alum sodium roasting with calcium. Because it contains hexavalent chromium and sodium and magnesium exceed the standard, making it harmless and resourceful has become a worldwide problem. In addition, chromium slag is extremely harmful to the ecological environment and people's life and health, so chromium slag has long been listed as the number one harmful solid waste in the chemical industry. Over the past half a century, a lot of manpower and material resources have been invested in research at home and abroad, and many n...

Claims

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Application Information

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IPC IPC(8): C22B3/04C22B3/22C22B34/32C22B26/20C22B26/22
CPCY02P10/20
Inventor 王云山杨刚张金平
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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