Pretreatment method for chromium powder ore used for smelting production of ferrochrome alloy

A ferrochromium alloy and a smelting method technology are applied in the field of pretreatment of chromium fine ore, which can solve the problems of unfavorable industrial production, secondary pollution of dust and high production cost, and achieve less pollution from fine ore, lower smelting cost, and lower smelting energy consumption. Effect

Active Publication Date: 2013-04-17
中国中化股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this process method has the following disadvantages: firstly, it is necessary to grind the chromium powder ore into a fine powder of 0.074mm and greater than 65%, and then pelletize and coat a layer of fuel on the surface of the sphere before sintering. The operation is complicated and the production cost is high. The step of grinding chromium powder ore into 0.074mm may also produce dust secondary pollution, so it is not conducive to industrial production
Using this process to produce chromium-containing sinter eliminates the problem of coke ratio increase caused by a large amount of limestone directly entering the furnace, but this process has the following disadvantages: it needs to add iron-containing materials and can only enter the blast furnace to smelt chromium 1-30 % of chromium pig iron
This method not only has high cost, but also cannot meet the requirement of submerged arc furnace to smelt ferrochrome containing more than 50% chromium.

Method used

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  • Pretreatment method for chromium powder ore used for smelting production of ferrochrome alloy
  • Pretreatment method for chromium powder ore used for smelting production of ferrochrome alloy

Examples

Experimental program
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Effect test

Embodiment 1

[0062] Main raw material: Turkish chrome powder ore, the particle size is 0-10mm, and the content (by weight %) of all raw materials is 88%;

[0063] Auxiliary raw materials:

[0064] Flux: common stone powder, content (by weight %) of all raw materials is 4%;

[0065] Reducing agent: pulverized coal (by weight %) of all raw materials is 4%;

[0066] Fuel: blue charcoal powder, content (by weight %) of all raw materials is 4%.

[0067] Such as figure 1 As shown, the main raw materials and auxiliary raw materials are mixed, and water is sprayed during the mixing process of the main and auxiliary materials, so that the humidity of the mixed material reaches 10% after mixing evenly, and then the mixture is arranged in a ring sintering machine (thickness is 50cm ). The fuel in the sinter bed is ignited and burned by coal gas, and the upper part of the sinter layer reaches 1100°C, and then gradually burns downward under the negative pressure of the induced draft fan. The intern...

Embodiment 2

[0071] Main raw material: South African chrome powder ore, the content (by weight %) of all raw materials is 83%;

[0072] Auxiliary raw materials:

[0073] Flux: silica powder, content (by weight %) of all raw materials is 5%;

[0074] Reductant: coke powder, content (by weight %) of all raw materials is 6%;

[0075] Fuel: pulverized coal, the content (by weight %) of all raw materials is 6%.

[0076] Such as figure 1As shown, the main raw materials and auxiliary raw materials are mixed, and water is sprayed during the mixing process of the main and auxiliary materials, so that the humidity of the mixed material reaches 11% after mixing evenly, and then the mixture is arranged in a ring sintering machine (thickness is 35cm ). The fuel in the sinter bed is ignited and burned by coal gas, and the upper part of the sinter layer reaches 1100°C, and then gradually burns downward under the negative pressure of the induced draft fan. The internal temperature of the sinter bed is...

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Abstract

The invention provides a pretreatment method for a chromium powder ore used for smelting production of a ferrochrome alloy. The method comprises the steps of 1) mixing the chromium powder ore with a fluxing agent, a reducing agent and a fuel to obtain a mixture; and 2) sintering the mixture to obtain a sintered material. The method is short in process flow and low in sintering cost and is simple and practicable, and production of powder ore pollutions is not easy, so that relatively cheap powder chromium ore can be fully used, smelting consumption can be decreased greatly, and further smelting cost of the ferrochrome is reduced. The sintered material obtained by the sintering treatment method can be directly introduced into an ore smelting electric arc furnace for smelting after smashing. The method can enhance reducibility of furnace charging materials, reduce energy consumption and decrease usage proportion of other auxiliary materials such as coke, silica and the like in the smelting furnace charging materials. At the same time, possibility of reversing materials is greatly decreased, production security is increased and probability of production accidents is reduced greatly.

Description

technical field [0001] The invention relates to a method for pretreating chrome powder ore before ferrochrome alloy smelting and production. Background technique [0002] After the chrome ore is mined, the proportion of lump ore obtained from raw ore through beneficiation is not high, generally about 30%, and most of them are fine ore. Therefore, the price of fine ore in the market is usually about 10% lower than that of lump ore. Most of the smelting ferrochrome alloys in my country use ordinary submerged arc furnaces, which require good air permeability of the furnace charge, otherwise it will cause material turnover and production accidents. This requires a high proportion of lumpy ore in chrome ore, usually reaching more than 70%, thus resulting in a relatively high production cost of ferrochrome. If the fine ore can be made into pellets that meet the smelting requirements, the above problems can be solved. [0003] Generally, powder ore agglomeration techniques includ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B1/16C22B1/00C22B4/06
Inventor 张新琪
Owner 中国中化股份有限公司
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