Composite binder for iron ore pellets and preparation method thereof

Abstract

The invention in particular relates to a composite binder for iron ore pellets and a preparation method thereof. The technical scheme is that the method comprises the following steps of: mixing 40 to 70 weight percent of sodium bentonite and 30 to 60 weight percent of rectorite; adding 0.1 to 1 weight percent of additive; uniformly mixing; and grinding until the particle size is less than 200 meshes to obtain the composite binder for the iron ore pellets, wherein the additive is prepared by mixing an adhesion promoter and a reinforcing agent in the mass ratio of 1:(1.5-9) and grinding the mixture until the particle size is less than 200 meshes; the adhesion promoter is more than two of polyacrylamide, modified starch and polyethylene oxide; and the reinforcing agent is one of carboxymethyl cellulose and humic acid salt. By the method, the equipment investment is not increased, the original production process is not changed and the quality of the pellets can be improved; and the composite binder prepared by the method has the characteristics of improving compression strength and dropping strength of green pellets, compressive strength and cracking temperature of dry pellets, compressive strength of and total iron grade of finished pellets.

Description

technical field [0001] The invention belongs to the technical field of iron ore pellets, and in particular relates to a composite binder for iron ore pellets and a preparation method thereof. Background technique [0002] Pellets have the advantages of uniform particle size, high cold strength, high iron grade, and good reducibility, and are an indispensable high-quality furnace charge (Zhang Yimin. Pellet Production Technology. Beijing: Metallurgical Industry Press, 2005, 1 -13), it has played an obvious positive role in optimizing the structure of the blast furnace charge, improving the technical and economic indicators of ironmaking, promoting energy saving and reducing consumption, and achieving environmental friendliness. [0003] Binder is an indispensable component in iron ore pellets. Studies have shown that a binder with good performance has very obvious practical significance for improving the quality of pellets and the economic and technical indicators of ironmak...

AI Technical Summary

Problems solved by technology

Generally speaking, the thermal stability of the inorganic binder is good, and the compressive strength of the dry ball produced is also good, but it is inevitable that the amount of the binder is large, the strength of the green ball is poor, and impurities are brought in, which reduces the strength of the ball. However, although the existing organic binder has good cohesiveness and spheroidization, less impurities are brought in, and the grade of the finished ball is high, the thermal performance is generally poor. The high price and the physical and metallurgical properties of the finished balls cannot fully meet the requirements of the blast furnace process (Huang Tianzheng, Research Status and Development of Pellet Additives, Sintered Pellets, 1997, 22(3): 1-7), Therefore, it is difficult to popularize and apply in industry

[0005] In recent years, people have developed an organic / inorganic composite binder with bentonite as the main component. The amount of this kind of binder is relatively small, which improves the quality of the pellets to a certain extent, but still has a low burst temperature. , low compressive strength of the finished ball