Method for preventing hardening of filter material of blast furnace water slag bottom filter system

Abstract

The invention provides a method for preventing hardening of a filter material of a blast furnace water slag bottom filter system. The method comprises the following steps: controlling slag flushing water pressure within a set range; adopting an anti-hardening filter arrangement structure in a bottom filter tank (8); adopting precise slag grabbing equipment to carry out slag remaining and removing operation on a slag particle layer (85) in the bottom filter tank (8); and when the filtering capacity of the surface layer filter material of the filter layer (82) is greatly reduced, replacing the surface layer filter material (821) of the filter layer (82) in the bottom filter tank (8) by adopting the precise slag grabbing equipment. According to the method for preventing hardening of the filter material of the blast furnace water slag bottom filter system, the problem that the filter layer is easy to harden is thoroughly solved through the whole-process treatment from slag flushing water pressure adjustment of source treatment to final slag grabbing and cleaning.

Description

technical field [0001] The invention relates to the technical field of blast furnace ironmaking equipment, in particular to a method for preventing hardening of filter materials in a blast furnace slag bottom filtration system. Background technique [0002] High-temperature liquid slag (1350°C-1500°C) is produced during blast furnace smelting, and domestic production of molten iron produces about 280 million tons of high-temperature liquid slag each year. [0003] At home and abroad, the sedimentation filtration method (often called the bottom filtration method) water slag process is usually used to treat the slag. Hydraulic slag flushing is carried out in front of the blast furnace, and the slag is crushed by water quenching to become a loose slag-water mixture (commonly known as water slag), and the water slag enters the bottom filter tank through the slag flushing ditch. [0004] The filter layer at the bottom of the bottom filter is usually composed of filter materials ...

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Problems solved by technology

If the filter layer is too tight, the filtration efficiency will be low, and the separation of the slag-water mixture cannot be completed quickly. When the slag is caught, water will be caught and the slag will be caught, which will not fully realize the recycling of water resources; if the filter layer is too sparse, it will lead to fine particles The slag particles cannot be isolated, and the fine slag particles and liquid water enter the circulating water system together, causing serious wear and tear to the pipes and valves of the circulating water system, affecting the smooth operation of the water slag process

[0006]Blast furnace slag flushing water contains a certain amount of slag wool, which is easy to block the filter gap of the filter layer during the filtration process of slag-water separation. The filter layer is compacted, and the filter layer after compaction loses its filtering function, which leads to the failure of the production of the water slag system. The problem of filter layer compaction has become a difficult problem that needs to be solved urgently in the bottom filtration process. Once the filter material is compacted, it will be more difficult to replace. It will seriously affect the smooth progress of blast furnace production

In order to avoid or slow down the hardening of the filter layer, it is generally used to backwash the filter material through the filter tube at the bottom of the bottom filter tank with slag flushing water, and use the backwash water to improve the activity of the filter material, but because the filter tube is arranged at the bottom of the filter tank, With water collection as the main purpose, the backwashing effect is not ideal, and the effect on delaying the compaction of the filter material will continue to weaken as the production progresses

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