A method for resource utilization of chromium-containing waste slag compound pellets by sintering method

A technology of composite pellets and chromium waste residue, applied in the field of metallurgy and environmental protection, can solve the problems of waste of resources, poor sinter strength, and high fuel consumption, and achieve the effects of increasing the probability of contact, increasing the roasting temperature, and increasing the reduction speed.

Active Publication Date: 2022-03-29
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the high melting point of chromium spinel, it is difficult to form a low melting point liquid phase, and its sinterability mainly depends on the performance of gangue and the added flux. high and poor sinter strength, the sintering method needs to be further improved and perfected
[0004] On the other hand, the annual production of chromium-containing waste residue in my country is nearly one million tons, and the chromium content in chromium residue is relatively high (3% to 7%). Its utilization rate is less than 10%, and the accumulated stockpile of chromium slag has exceeded 7 million tons
Chromium slag contains highly toxic hexavalent chromium, which is a dangerous solid waste, and its stockpiling brings huge environmental problems
However, the chromium in the chromium slag has not been effectively utilized, resulting in a huge waste of resources

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] First, mix chromium-containing waste slag, reducing agent and binder to prepare chromium slag composite pellets, and mix iron ore, flux, coke powder, etc. to make pellets, and then layer the composite pellets and pellets Distributed to the sintering machine for roasting to obtain chromium-containing sintered ore.

[0034] The chromium-containing waste slag is chromium salt slag, the reducing agent is coke powder and anthracite, the binder is bentonite (the addition amount is about 1% of the pellet material), the iron ore in the granular material is chromite, and the flux is quicklime.

[0035] In the middle layer of the composite pellets, the mass ratio of the carbon element in the coke powder to the oxygen element in the chromium slag is 0.5:1.

[0036] The diameter of the inner sphere is 2 mm, the diameter of the middle layer is 6 mm, and the diameter of the pellet is 10 mm.

[0037] The pelletizing time of the composite pellets is 12 minutes, and the pelletizing mac...

Embodiment 2

[0045] First, mix chromium-containing waste slag, reducing agent and binder to prepare chromium slag composite pellets, and mix iron ore, flux, coke powder, etc. to make pellets, and then layer the composite pellets and pellets Distributed to the sintering machine for roasting to obtain chromium-containing sintered ore.

[0046] The chromium-containing waste residue is stainless steel pickling mud, the reducing agent is coke powder and anthracite, the binding agent is bentonite (the addition amount is about 1% of the pellet material), and the iron ore in the granular material is a mixture of laterite nickel ore and magnetite. Mixture, the flux is quicklime and dolomite.

[0047] In the middle layer of the composite pellets, the mass ratio of the carbon element in the coke powder to the oxygen element in the chromium slag is 0.5:1.

[0048] The inner sphere has a diameter of 2 mm, the middle layer has a diameter of 6 mm, and the pellets have a diameter of 11 mm.

[0049] The ...

Embodiment 3

[0057] First, mix chromium-containing waste slag, reducing agent and binder to prepare chromium slag composite pellets, and mix iron ore, flux, coke powder, etc. to make pellets, and then layer the composite pellets and pellets Distributed to the sintering machine for roasting to obtain chromium-containing sintered ore.

[0058] The chromium-containing waste slag is ferrochrome slag, the reducing agent is coke powder and anthracite, the binder is bentonite (the addition amount is about 1% of the pellet material), the iron ore in the granular material is magnetite, and the flux is quicklime.

[0059] In the middle layer of the composite pellets, the mass ratio of the carbon element in the coke powder to the oxygen element in the chromium slag is 0.4:1.

[0060] The inner sphere has a diameter of 3 mm, the middle layer has a diameter of 7 mm, and the pellets have a diameter of 12 mm.

[0061] The pelletizing time of the composite pellets is 12 minutes, and the pelletizing machi...

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Abstract

The invention discloses a method for realizing resource utilization of chromium-containing waste slag composite pellets by adopting a sintering method. The method is to mix raw materials including chromium-containing waste slag and a reducing agent to obtain pellets; at the same time, the pellets including Raw materials including iron ore, flux and coke powder are mixed and granulated to obtain granules; then the pellets and granules are mixed and distributed in layers on the sintering machine for sintering to obtain chromium-containing sintered ore, making full use of the pellets The structural advantages of the material, the automatic heat storage of the material layer and the heating of the pellets by the thermal field of the pellets make the high-valent chromium compounds in the pellets quickly reduced to metal chromium or chromium carbide under high temperature conditions, and realize the recovery of chromium-containing waste slag. Thoroughly detoxifying and simultaneously obtaining chromium-containing sinter with excellent performance can be used as high-quality charge for smelting chromium-containing hot metal or ferrochromium alloy. This method realizes resource utilization of chromium-containing waste slag, is easy to realize industrialization, and has good application prospects.

Description

technical field [0001] The invention relates to a method for resource utilization of chromium-containing waste slag, in particular to a method for utilizing chromium-containing waste slag in an iron ore sintering process to realize thorough detoxification of chromium-containing waste slag in one step and obtaining high-quality chromium-containing composite sintered ore. Metallurgical environmental protection technology field. Background technique [0002] my country is the world's largest consumer of chromium resources, and its chromium consumption exceeds one-third of the world's production of chromium-containing raw materials, but my country's annual output of chromium-containing raw materials is less than 1% of the world's annual production. The huge demand makes chromium One of the metals with the highest dependence on foreign countries in my country, the contradiction between supply and demand is very prominent. In addition, with the continuous development of chrome ore...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B1/242C22B1/248C22B1/22
CPCC22B1/2406C22B1/242C22B1/248C22B1/22Y02P10/20
Inventor 张元波苏子键涂义康姜涛李光辉范晓慧彭志伟饶明军朱应贤刘硕刘继成王嘉侯炜赵雪娟刘康林坤王琰成相霖
Owner CENT SOUTH UNIV
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