Blast furnace slag dry granulation and heat recovery system and method

Abstract

The invention discloses a blast furnace slag dry granulation and heat recovery system and method in the field of blast furnace ironmaking. The system comprises a heat preservation buffer tank, a granulation device and a heat exchange tank; a slag discharging pipe is arranged at the bottom of a tank body of the heat preservation buffer tank, and a plug bar is arranged in the slag discharging pipe; the granulation device comprises a granulation bin, a spraying device is arranged at the upper portion of the interior of the granulation bin, a rotational granulation rotary disc is arranged, an unloading chute is arranged at the bottom, and a slag grain collecting opening is formed in the tail end of the unloading chute; and the heat exchange tank comprises a heat exchange tank body, a cooling air inlet is formed at the lower portion of the heat exchange tank body, and a hot air exhaust opening is formed at the upper portion of the heat exchange tank body. By means of the blast furnace slag dry granulation and heat recovery system and method, contradiction between the blast furnace slag cooling speed and the recovery waste heat quality is overcome, and the running using rate and the heat recovery using rate of a blast furnace slag dry granulation device are improved. Meanwhile, slag grain raw materials rich in glass body and capable of meeting the requirement for cement production can be obtained from treated slag grains more easily.

Description

technical field [0001] The invention belongs to the field of blast furnace ironmaking, and in particular relates to a method and system for dry granulation and heat recovery of liquid blast furnace slag. Background technique [0002] Blast furnace slag is a by-product of the blast furnace ironmaking process. It is in a molten liquid state at a temperature of 1450-1650 °C. At present, the treatment of blast furnace slag in the industry mainly adopts the water quenching method (wet method) to rapidly cool the blast furnace slag to below 100°C. After dehydration, water slag is obtained, which is mainly used as raw material for cement production. This method causes the heat in the slag to be wasted in vain, and there is no recycling; two will consume a large amount of water resources; three, the environment will be polluted; It needs to be dried, which consumes a lot of energy. [0003] Since slag discharge is intermittent during blast furnace production, at 1000m 3 Take the...

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Problems solved by technology

The main reason is that the contradiction between the cooling speed of granulated slag and the quality of recovered waste heat is not solved, the problem of high investment and operation cost is not solved, the problem of secondary bonding of slag particles at high temperature is not solved, and the Can solve the problem of equipment operation reliability and durability under high temperature

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