Molten iron thermal insulating agent taking fly ash deducted from dry quenching as raw material and manufacturing and using method of molten iron thermal insulating agent

Abstract

The invention provides a molten iron thermal insulating agent taking fly ash deducted from dry quenching as a raw material and a manufacturing and using method of the molten iron thermal insulating agent. The molten iron thermal insulating agent comprises the following components in percentage by weight: 50%-100% of fly ash deducted from dry quenching, 0-50% of water-granulated blast furnace slag,and 0-10% of expanded perlite. Compared with the prior art, the molten iron thermal insulating agent and the manufacturing and using method have the beneficial effects that 1) 90%-100% of the raw material of the molten iron thermal insulating agent comprises metallurgical waste in a metallurgical enterprise, machining or grinding is not required, the cost is remarkably lower to that of the similar molten iron thermal insulating agent, the cost is continuously reduced according to a formula, and the cost reducing requirements of enterprises at different levels are met; 2) the molten iron thermal insulating agent can be tightly combined with high blast slag on the surface of molten iron, slagging is easy, the heat conductivity coefficient is small, the thermal insulating effect is stable and reliable, resulfurization is not needed, and the steelmaking cost is not increased; 3) the slag gathering effect is good, the crusting phenomenon of an opening of a molten iron jar is reduced, and the workload and the working difficulty of manual slag removal are reduced; and 4) the economic benefits and the environmental benefits are remarkable, and the molten iron thermal insulating agent hasremarkable economic benefits and popularization and application values within the industry.

Description

technical field [0001] The invention relates to the field of heat preservation of metallurgical melts, in particular to a heat preservation agent for molten iron using CDQ dust as a raw material and methods for its manufacture and use. Background technique [0002] Hot metal tanks and torpedo tanks are basic equipment in ironworks. In the process of sending the molten iron produced by the blast furnace to the next process, there will inevitably be iron loss and temperature reduction, that is, heat loss. Relatively speaking, due to the poor insulation conditions of the open iron ladle, the temperature drop of the molten iron is significantly higher than that of the torpedo pot under the same conditions. [0003] The temperature of molten iron has a great influence on steelmaking. According to the converter smelting process, the heat of converter smelting basically comes from the physical heat and chemical heat of molten iron. Under the condition of constant chemical heat, t...

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Problems solved by technology

But this invention has the following problems, one is that the S content in the fly ash is relatively high, and when it is used as the main raw material for hot metal insulation, the S content of the hot metal will be increased, which increases the cost of hot metal pretreatment or converter smelting; the other is to add 3 to 5 % of fluorspar, and the F in fluorite seriously erodes the lining of molten iron tanks and converters, and is not conducive to the control of molten steel refining process. At present, most iron and steel enterprises have minimized or even stopped adding fluorspar to molten iron tanks or converters

[0007] However, metallurgical enterprises have a large amount of surplus CDQ dedusting ash, which has a carbon content of over 80%, is irregularly granular, has low density, high calorific value, and high porosity. , and because of its small particle size, it is easy to spontaneously ignite. It is mainly used for blast furnace injection at present, and there are few other utilization methods. It is difficult to effectively handle and safely place it when the surplus is large, and the cost is low.

[0008] In summary, the hot metal heat preservation agent in the prior art has problems such as poor heat preservation effect, high cost, and large dosage, which can no longer meet the actual needs of continuously reducing ironmaking costs. It is necessary to research and develop a lower cost and stable heat preservation effect. Hot metal heat preservation agent