Method for reduction roasting of hematite by using sludge as reducer

Abstract

The invention discloses a method for the reduction roasting of hematite by using sludge as a reducer, which comprises: crushing the hematite till the particle size of the hematite is less than 6 millimeters; uniformly mixing mechanically-dehydrated wet sludge from sewage treatment plant with a hematite sample to obtain a hematite and sludge mixture, wherein the mass ratio of the wet sludge to the hematite is 0.5-2.0:1; drying the hematite and sludge mixture naturally or in the sun till the water content of the hematite and sludge mixture is less than 20 percent; and performing reduction roasting at 550 to 700 DEG C for 1 to 4 hours, wherein the product of the roasting is the reduced product of the hematite, the iron in the reduced product exists in form of magnetite (Fe3O4), and the reduction rate of the hematite is more than 75 percent. The method has the advantages that: (1), a reducer which is cheap and widely available is provided for the reduction roasting of the hematite; and (2) the treatment and recycling of the sludge can be realized at the same time.

Description

technical field [0001] The invention relates to a method for reducing and roasting hematite by using sludge as a reducing agent. Background technique [0002] Hematite (Fe 2 o 3 ) is an important iron-containing mineral and one of the main iron ore raw materials for my country's iron and steel industry. Hematite ore has the characteristics of complex composition, tight intercalation of iron oxides and gangues, and fine intercalation particle size. It is difficult to achieve a satisfactory monomer dissociation degree during the grinding process, which causes difficulties in the hematite separation process. Hematite has weak magnetism, and strong magnetic separation can be used for effective separation in theory. Larger particle size, or insufficient magnetic field force, make it difficult to achieve satisfactory results in the strong magnetic separation process of hematite. Therefore, in production practice, the hematite is generally reduced and roasted first to reduce it ...

AI Technical Summary

Problems solved by technology

However, as an organic part of the sewage treatment system, the development of sludge treatment and disposal technology is slow, which restricts the process of sewage treatment to a certain extent.

At present, most of the sludge in our country has only undergone preliminary treatment, and then it is temporarily stored in disorder or simply landfilled, which not only occupies a large area of ​​land resources, destroys the ecological environment, affects human health, but also wastes resources.