The Preparation Of Organic Modified Bentonite And The Mechanism Of Organic Modified Bentonite Improving The Strength Of Iron Ore Pellets

The proportion of iron ore pellet in steelmaking production keeps growing because of its high iron grade and uniform size. As one of the most indispensable ingredients for iron ore pelletizing, binder is very important for the production process of pellets and the quality of final products. The development and application of new binder is an important subject to make comprehensively use of inferior iron ores and increase the economic benefic of ironmaking and steelmaking plants.In this paper, organic modified bentonite was firstly prepared by mixing a certain amount of composite additive, bentonite and water under the action of mechanical stirring force, then pellet forming experiments were taken with it. The organic modified bentonite’s influence on the oxidizing roasting of pellets is studied. Here are the main conclusions:(1) Under the effect of water, composite additive and mechanical force, the original multi-layer lamellar structure of bentonite turned into single layer structure, and connected with each other.(2) There is a certain linear relationship between the relative moisture content of organic modified bentonite and the quality of pellets, with the increase of the relative moisture content of organic modified bentonite, the incidence strength and the compression strength of green pellets, the compression strength of preheated pellets and roasted pellets are obviously improved.(3) After adding the organic modified bentonite, The incidence strength and the compression strength of green pellets rised from1.7times/0.5m,9.72N/p to3.0times/0.5m,14.24N/p, the compression strength of preheated pellets and roasted pellets rised from208N/p,2668N/p to271N/p,3693N/p.(4) After adding the organic modified bentonite, the number of single particle decreased significantly and the effect between particles became more closely in the green pellets, thus the strength of green pellets were improved. Organic modified bentonite was evenly sprayed on the blending particles, which strengthened the particles aggregation, optimized the dissemination relationship between coarse and fine particles, which makes crystal structure more compact in the process of preheating and roasting, and enhanced the intensity of preheated pellets and roasted pellets.