A kind of method for preparing chromium salt

A technology of chromium salt and oxygen, applied in the direction of chromate/dichromate, etc., can solve the problems of low chromium recovery rate and restriction of chromium recovery rate, so as to promote endothermic and exothermic reactions and benefit the environment High effect of protection and heating efficiency

Inactive Publication Date: 2016-09-28
LIAONING SING HORN GROUP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This is the traditional chromium salt roasting process with low chromium yield and chromium slag Cr 2 o 3 The main reason why the content of chromium remains high all the time, which seriously restricts the improvement of the recovery rate of chromium

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Mix chromium ore and industrial soda ash at a ratio of 100:90 to obtain a mixture. In an atmosphere with an oxygen content of 20-23%, use microwaves with a frequency of 2400-2500MHz to heat and roast the mixture. The roasting temperature is 1050°C and the roasting time is 1.5h. Roasted clinker is obtained, and the obtained roasted clinker is immersed in water to obtain a leaching solution for the preparation of chromium salts; the clinker and leaching residue are chemically analyzed, and the insoluble waste residue contains 2.5% chromium (calculated as chromium trioxide), and the chromium leaching rate is 85%. The utilization rate of chromium in the preparation of chromium salt is 95%; the total utilization rate of chromium in chromium slag reaches 100% by combining with the detoxification blast furnace of chromium slag.

Embodiment 2

[0036] Mix chromium slag and industrial soda ash at a ratio of 100:120, and statically roast in a microwave oven with an electromagnetic wave frequency of 890-940MHz in an oxygen-rich atmosphere with an oxygen content of 23-25%. The roasting temperature is 1000°C and the roasting time is 1.5 h to get roasted clinker, water extraction gained roasted clinker to obtain leachate for the preparation of chromium salt; clinker and leaching residue through chemical analysis, insoluble waste residue chromium (calculated as dichromium oxide) is 2%, chromium leaching rate 92%; the utilization rate of chromium in the preparation of chromium salt is 98%, and the total utilization rate of chromium in the chromium slag reaches 100% by combining with the chromium slag detoxification blast furnace.

Embodiment 3

[0038] Mix chromium slag and industrial soda ash at a ratio of 100:130, and statically roast in a microwave oven with an electromagnetic wave frequency of 890-940MHz in an oxygen-rich atmosphere with an oxygen content greater than 30%. The roasting temperature is 1100°C and the roasting time is 1.5h. Obtain roasted clinker, the gained roasted clinker of water leaching obtains leaching solution and is used for preparing chromium salt; After chemical analysis of clinker and leaching slag, the insoluble waste residue containing chromium (calculated as dichromium oxide) is 2.5%, and the chromium leaching rate is 95%. %; The utilization rate of chromium in the preparation of chromium salt is 99%, and the total utilization rate of chromium in chromium slag reaches 100% by combining with the blast furnace for detoxifying chromium slag.

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Abstract

The invention discloses a method for preparing chromium salt. It is characterized in that: the raw material containing chromium oxide (chromium ore or chromium slag) and sodium carbonate are fully and uniformly mixed, and in an atmosphere with an oxygen content greater than 20%, microwave is used as a heat source to carry out oxidative roasting, and the roasting temperature is 900 ℃ to 20%. 1100°C, holding time of 0.5-2.5h, using water immersion roasting product to prepare chromium salt from leaching solution, chemical analysis of clinker and leaching residue, insoluble waste residue containing chromium (calculated as chromium trioxide) is less than 5%. The invention not only reduces the chromium content in the chromium slag discharged from the outside, improves the utilization rate of chromium in the production process of the chromium salt, and effectively saves the chromium ore resources, but also uses microwaves as a heat source to replace the traditional coal and natural gas heating, thereby saving resources and environmental protection advantages.

Description

technical field [0001] The invention belongs to the technical field of chromium slag treatment, and in particular relates to a method for preparing chromium salt. Background technique [0002] Chromium slag is the main industrial waste slag produced during the production of chromium salts. It is a highly toxic and hazardous waste. If it is not treated for a long time, it will seriously pollute the ecological environment and endanger various organisms. Recycling chromium in chromium slag is very important for pollution control and The comprehensive utilization of chromium slag resources has important practical significance. [0003] Chromium salt is produced by mixing chromium ore with soda ash and roasting at high temperature. Metal chromium is produced from water-insoluble trivalent chromium to water-soluble hexavalent chromium, so as to achieve the purpose of separating metal chromium from gangue. The traditional heating method The temperature condition of the reaction is...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01G37/14
Inventor 董达关振波于伟东武涛
Owner LIAONING SING HORN GROUP CO LTD
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