Method for manufacturing sintering ore from limonite with high content of crystal water

Abstract

The invention provides a method for manufacturing sintering ore from limonite with high content of crystal water. The method is characterized by comprising the following steps: taking limonite with high content of physical water and crystal water as the raw material; and subjecting the limonite to material proportioning, stirring granulation, pallet-feeding, sintering ignition and CaCl2 solution spraying to obtain the sintering ore. The method can effectively overcome the shortcomings that the strength of the sintering ore is reduced and thus the output of the sintering ore is influenced, for the limonite with high content of crystal water is prone to shrink to form thin-wall large pores due to the high burning loss rate in the sintering process; particularly, the method can inhibit the crystal transition of the sintering ore and improve the low-temperature reduction degradation performance by adding SYP sintering promoting agent; in addition, the method can inhibit the sintering ore from undergoing the reduction degradation within the temperature range of 450 to 550 DEG C and effectively reduce the amount of secondary powder generated in the reducing atmosphere within the temperature range of 450 to 550 DEG C; and the method is beneficial to improve the ventilation property of stock columns of a blast furnace and improve the smooth operation of furnace practice thereof, and the method can solve the problem of the shortage of iron ore resources in the long run and offer a guarantee to the industrial popularization and application of limonite.

Description

technical field [0001] The invention relates to a production method of sintered ore, in particular to a method for producing sintered ore by using high physical water and crystalline limonite, and belongs to the technical field of metallurgical sintering. Background technique [0002] Limonite usually has a high content of physical water and crystal water, so the burning loss is high, and it is easy to shrink during the sintering process to form a thin-walled macropore structure, thereby reducing the strength of the sinter and affecting the output of the sinter. The technical research of producing sintered ore with limonite is mainly in Australia, Japan, France, China and other countries. The physical water and crystallization water content of limonite used in it is 10-14%, but some limonite is expensive such as Vietnam. Sand limonite, its physical water and crystal water are as high as 21-25%, and the grade is only 53% (while the grade of ordinary limonite is above 58%), so...

AI Technical Summary

Problems solved by technology

The limonite content in Guisha ore minerals is relatively high (85%), and the burning loss is large (11.30%). During the sintering process, the shrinkage is large, which is easy to cause edge effects, which increases the edge airflow and weakens the central airflow, which affects the sintering process. consistency and adversely affect the yield and quality of sinter;

[0004] (2) Guisha ore has very strong water absorption and contains high physical water and crystal water. During the sintering process, the over-humidity layer becomes thicker, resulting in poor air permeability of the sintered material layer, increased draft resistance, and reduced vertical sintering speed. Adverse effects of reduced utilization factor;

[0005] (3) The burning loss of Guisha mine is large, the content of physical water and crystal water is high, and the heat consumption is large

In addition, the strength of sintered ore is poor, the yield is low, and the amount of returned ore is large

In order to meet the heat requirements of the sintering process and improve the quality of sinter output, the consumption of solid fuel during sintering of Guisha Mine increases;

[0006] (4) During the sintering process of Guisha ore, a large amount of internal crystal water escapes, accompanied by a strong bursting phenomenon. The sintered ore is prone to form a thin-walled macroporous structure, with many cracks in the pore wall matrix and stress concentration, which affects the quality of the sintered ore.

At the same time, due to the complex origin of limonite, relatively weak magnetic properties, uneven particle size, and easy mudification during the grinding process, it is quite difficult to beneficiate limonite.

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