High-temperature liquid slag granulation and waste heat recovery method

Abstract

The invention discloses a high-temperature liquid slag granulation and waste heat recovery method. Low-temperature air, water and low-temperature carbon dioxide are sequentially selected as heat exchange media, and a three-stage three-medium method is adopted for achieving heat exchange with high-temperature liquid slag to obtain normal-temperature solid slag and heat exchange media absorbing heat. The high-temperature liquid slag granulation and waste heat recovery method specifically comprises the steps that the low-temperature air is adopted to cool slag droplets formed after the high-temperature liquid slag is crushed to form high-temperature solid slag and high-temperature air; the water is adopted to cool the high-temperature solid slag to obtain medium-temperature solid slag and high-temperature water vapor; and countercurrent heat exchange is carried out between the low-temperature carbon dioxide and medium-temperature solid slag to obtain normal-temperature solid slag and high-temperature carbon dioxide. According to the split slag comprehensive utilization method combining centrifugal granulation and three-stage heat exchange, the water does not directly make contact withthe slag, the energy and resource properties of the hot slag are sufficiently considered, through multi-step cooling, the heat in the hot slag can be fully utilized, the low-temperature and high-temperature slag which can be used as raw materials for new plates and building floors can be obtained, and great significance is achieved for practice and popularization.

Description

technical field [0001] The invention belongs to the technical field of recycling metallurgical solid waste, and in particular relates to a method for granulating high-temperature liquid slag and recovering waste heat. Background technique [0002] High-temperature slag mainly includes blast furnace slag, converter slag and electric furnace slag, which are produced in the process of blast furnace ironmaking and converter or electric furnace steelmaking respectively. The temperature of high-temperature slag is as high as 1500-1700 ° C; thermal energy. [0003] The greater the production volume of steel, the greater the amount of slag. According to statistics, in 2018, the cumulative output of pig iron, crude steel and steel products in China was 771 million tons, 928 million tons and 1.106 billion tons respectively, correspondingly producing nearly 280 million tons of blast furnace slag and 140 million tons of steel slag. If there is 1.7*10 per ton of slag 9 Calculating the...

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Problems solved by technology

Facing the serious waste of resources and SO 2 Due to the large amount of harmful gas emissions, difficult process heat recovery, and the difficulty of comprehensive utilization of steel slag, the iron and steel industry urgently needs to research and develop a new process for comprehensive utilization of high-temperature slag that can effectively improve heat energy recovery and reduce harmful gas emissions.

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