Blast furnace slag granulation and waste heat utilization process technology and equipment

Abstract

The invention provides a process technology for granulating blast-furnace slag and utilizing waste heat. The process technology is characterized by comprising the following steps of: performing primary cooling and triple granulation on high-temperature molten slag from a blast furnace in a slag primary cooling device to form fine granules with diameter of less than 3mm and temperature of about 800-1,000 DEG C; discharging the fine granules through a high-temperature slag discharge valve; entering a slag basket and conveying to the upper part of a slag secondary cooling device; falling to the lower part of the slag secondary cooling device along a plurality of layers of baffle heat exchange components which are arranged in the slag secondary cooling device; and cooling to about 200 DEG C and discharging through a low-temperature slag discharging valve, wherein waste heat of normal pressure steam of 200 DEG C can be recovered by the slag primary cooling device; and waste heat of hot circulating air of over 600 DEG C can be recovered by the slag secondary cooling device. The invention provides equipment for granulating blast-furnace slag and utilizing waste heat. The equipment mainlycomprises the slag primary cooling device, the slag secondary cooling device, a waste heat boiler and the like. The process technology and the equipment have the advantages of good granulation effectof the molten slag, small and uniform size of slag granules, almost zero new water consumption and low environmental pollution.

Description

Technical field: [0001] The invention relates to the technical field of ironmaking, in particular to the technical field of blast furnace slag granulation and waste heat utilization technology and equipment. Background technique: [0002] In the process of blast furnace ironmaking, a large amount of coke and other fuels are used to burn hot melted ore to smelt molten iron. During the smelting process, a large amount of blast furnace liquid slag is produced at the same time. These blast furnace slags carry a lot of sensible heat during the smelting process, so blast furnace slag is One of the main products produced in the steel production process is also a very valuable secondary resource and secondary energy. According to the actual blast furnace production data in my country, about 280-480kg of blast furnace slag is produced for every ton of pig iron smelted, and the enthalpy of slag produced by every ton of pig iron smelted is equivalent to 23.34kg of standard coal. of hea...

AI Technical Summary

Problems solved by technology

Especially in the high-temperature section of high-temperature slag above 800-1000 °C, the required cooling rate must be greater than 10 °C / s. If the cooling rate is slow, the content of glass in the slag after granulation will be less, which will reduce the activity as a cement additive. , reducing the use value

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