Method for improving compressive strength of alkaline pellets prepared from limestone

Abstract

The invention discloses a method for improving the compressive strength of alkaline pellets prepared from limestone. The method comprises the following steps that 1, treated magnesium oxide is prepared; 2, mixed mineral powder is prepared; and 3, a roasted material is prepared and pelletized, prepared green pellets are screened and roasted, and the use amount of adhesive bentonite is controlled to be 1%-2.5% of the weight of the roasted material. Magnesium oxide is subjected to primary treatment, so that magnesium oxide has high porosity, oxygen can enter the pellets through pores in the oxygen enrichment process, oxidation of iron ore particles is improved, the compressive strength of the pellets is improved, and the technical problems that the compressive strength of the alkaline pellets prepared from the limestone can be improved by increasing the roasting temperature within a certain range, but energy consumption is increased by the too high temperature, and the compressive strength of the pellets is affected due to the fact that excessive liquid phases are generated are solved.

Description

technical field

[0001] The invention belongs to the technical field of blast furnace ironmaking, in particular to a method for increasing the compressive strength of alkaline pellets mixed with limestone. Background technique

[0002] Pellets are one of the main raw materials for blast furnace ironmaking. At present, ordinary acid pellets are mainly produced in the market. Acid pellets are pellets of natural alkalinity, SiO 2 and Al 2 o 3 The content of other elements is relatively high, while the content of alkaline substances such as calcium and magnesium is low, so it can only be used in conjunction with high-basic sintered ore in blast furnaces. Pellets with binary alkalinity above 0.6% are called alkaline pellets. Alkaline pellets have the advantages of high reducibility and good droplet performance, but it is difficult to improve the compressive strength of alkaline pellets, especially with the increase of alkalinity, the compressive strength of alkaline pellets de...