SU834170A1 - Charge for making pellets - Google Patents

Description

(54) CHARGE FOR PRODUCTION OF PELLETS

I

The invention relates to the preparation of iron ore material for metallurgical processing and can be used in the iron and steel industry.

Blend compositions are known in which bentonite and alumina ore 1 are used as reinforcing additives.

However, an increase in the amount of bentonite in the charge leads to its dilution by iron.

Closest to the proposed technical essence is a mixture for the production of pellets, containing, wt.%: Bentonite 0.5-1.5; alumina ore 2-15; iron ore material else 2.,

The disadvantage of the known charge is that the introduction of significant amounts of alumina additives leads to its dilution by iron.

The purpose of the invention is to improve the quality of baked pellets.

This goal is achieved by introducing rich oxidized iron ore with an iron content of 55-56%, a particle size of 0.5 mm, in which the content of the class-0.5-0.25 mm is 4-%, as a hardening additive. 2 / o, and content

class -0.063 mm - 40-55%, with the following ratio of ingredients, wt.%: bentonite 0.5-1.0; rich in oxidized ore 11 -15; iron ore material else. Hematite and martite ores (for example, Yakovlevsky and Lebedinsky deposits, KMA) can be used as rich oxidized ores.

The hardening effect of the proposed additive during calcination is determined by the fact that the distribution in the volume of pellets

particles of rich oxidized ore of various sizes provide, as it were, reinforcement of the pellet structure during firing, since the sintering rate of particles of this ore is nq at least one order of magnitude than magnetite. Since the roasting process develops in an oxidizing atmosphere (the process of strengthening is coupled with the oxidation process itself), with the addition of an additive of rich oxidized ore, the conditions for the initiation of a new phase during oxidation, i.e. the process of strengthening is intensified, since the embryos with a size larger than the critical one already exist. In addition, the presence in addition of a number of relatively large particles, which

Sintering slowly, contributes to a more uniform oxidation, and consequently, to the sintering of the pellet by volume.

The relationship between the strength of the pellets and the amount of additive and the time of its grinding in a rod mill is studied in laboratory experiments.

The dependence of the strength of the pellets after firing on the amount of the additive rich in oxidized iron ore of the optimal particle size distribution is given in table 1.

Table 1

Content is rich in oxidized iron. ore, wt.% A further increase in the amount of the additive of rich oxidized iron ore in the production of pellets from magnetite concentrate is not feasible, since the desired effect of increasing the strength of the pellets is achieved, and with further increase in the amount of the additive, the strength drops. The dependence of the yield of size classes and the strength of pellets, with the amount of the additive of 14 ° / o on the time of grinding of the additive in the core element is presented in Table 2.

table 2

Thus, the proposed mixture for the production of pellets can significantly improve the quality of roasted pellets.

Claims (2)

The economic effect is 300 thousand rubles. on one roasting mafina. Claims for producing pellets, including iron ore material, bentonite and hardening additive, characterized in that, in order to improve the quality of burned Q products, iron oxide with an iron content of 55-56 is added as a hardening additive to the mixture. % -0.5 mm size, in which the content of the class -0.5-0.25 mm is 4-270/0, the class -0.063 mm - 40-55%, with the following ratio of components, wt.% bentonite 0, 5-1.0; oxidized iron ore 11 -15; iron ore material else. Sources of information taken into account in the examination 1. M. Kopyrin and. Cherna metallurgists,. Lime universities. 1976, No. 4, p. 24-28. 2. USSR author's certificate number 435276, cl. From 22 to 1/243, 1976.