Method for increasing reduction degree of ferrochromium pellet ore and special system for method

Abstract

The invention discloses a method for increasing the reduction degree of ferrochromium pellet ore and a special system for the method. The method for increasing the reduction degree of the ferrochromium pellet ore comprises the steps that chromite is ground to be fine, so that chromite powder is obtained; the chromite powder and bentonite are evenly mixed, so that a mixture is obtained; and the mixture is made into green pellets in a pelletizer; and the green pellets are roasted, so that pellet ore is obtained. When the mixture is made into the green pellets in the pelletizer, a boric acid aqueous solution with the concentration being 1.0-3.0 wt% is added to serve as pelletizing water in the growing process of the green pellets. The invention further provides the special system for achieving the method. The special system comprises a chromite fine-grinding device, a mixing device, a chromite pelletizing device and a roasting device. According to the method for increasing the reduction degree of the ferrochromium pellet ore and the special system for the method, by means of the low-melting-point characteristic of boric acid, the liquid-phase formation temperature is decreased, the calcium ferrite content of the pellet ore is increased, the reduction temperature of the ferrochromium pellet ore is greatly decreased, the metallurgical performance of the ferrochromium pellet ore in the smelting reduction process is improved accordingly, and conditions are created for ferrochromium reduction.

Description

technical field [0001] The invention relates to a method for increasing the reduction degree of ferrochrome pellets and a special system thereof, belonging to the field of chromite metallurgical pellet smelting. Background technique [0002] It is difficult to reduce ferrochrome pellets during smelting. The main disadvantages are high reduction temperature and long time. In many related studies, adding sodium and calcium additives is one method, but the sodium element brought in accumulates with the amount, which also brings negative effects to the smelting equipment, such as low service life and reduced production and smelting intensity. [0003] The Chinese patent application No. 200910311007.4 discloses a sintering process of chromite ore powder. Its main technical feature is that the ore powder is finely ground to below -0.074mm, and then mixed with binder, fuel and water to make Balls, and then sintered to obtain ferrochrome sinter; this process only provides a treatme...

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Problems solved by technology

[0004] The Chinese patent application number 201310355953.5 discloses a chromite oxide pellet and its preparation method. The main technical solution is to mix a certain proportion of chromite, bentonite, metallurgical coke powder and dolomite, pelletize, Drying, preheating, roasting, and cooling to obtain chromite oxide pellets; the disadvantage of this process is that it only provides a production method for chromite oxide pellets, and there is no measure for the problem of difficult reduction of chromite pellets

Using chromite powder, iron ore powder, coal powder or coke powder, slaked lime, silica powder and other raw materials, after mixing, briquetting or pelletizing, drying and reducing at a high temperature of 1350-1500 °C; the disadvantage of this process is that : In the production of ferrochrome pellets, the various auxiliary materials added only meet the needs of pellet production, but still cannot solve the problems of difficult reduction and high reduction temperature in the next reduction process

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