A method for gasification dephosphorization and recycling of semi-steel smelting converter final slag

Abstract

The invention relates to a method of gasification dephophorization in semi-steel smelting converter final slag furnace. The method comprises the following steps that after tapping after smelting of asemi-steel smelting converter is finished, converter final slag is totally left in the furnace; after a furnace body is straightly shaken, quantitative SiC powder is added in the furnace from an overhead bunker; a gun is descended to enter slag regulating operation, and a gun position and a nitrogen flow rate are regulated for gasification dephophorization; after the slag regulating operation, thegun position and the nitrogen flow rate are rapidly lifted to a slag splashing and furnace protection level, and slag splashing and furnace protection operation is directly performed; and after slagsplashing is finished, furnace slag is totally left in the furnace and enters semi-steel smelting in a next furnace turn. For the method, by virtue of good dynamic conditions and vacuum conditions inthe period of slag splashing and furnace protection, by utilizing SiC as a dephosphorization agent to perform gasification dephophorization on the final slag, on one hand, the gasification dephophorization rate is improved, and on the other hand, an acid product after dephophorization lowers the alkalinity of molten slag, and phosphorus control production in the next furnace turn after slag remaining operation is facilitated. The technology is relatively low in popularization skill without investment of new equipment and manpower, does not have obvious influence on rhythm of production withoutadding production scheduling burden.

Description

technical field [0001] The invention relates to the technical field of steelmaking waste reuse, and relates to a dephosphorization treatment method for the high alkalinity characteristic of the final slag of a semi-steel smelting converter and a smelting method for recycling in a furnace. Background technique [0002] The output of converter slag is huge and the utilization rate is low. At present, most enterprises adopt the method of stacking the slag after iron selection. It does not conform to the production concept and environmental protection concept of the enterprise to save energy and reduce consumption. The reuse of converter slag is limited by free calcium oxide (f-CaO) and free magnesium oxide (f-MgO) in its composition, because of the corresponding volume change caused by the reaction with water, which in turn affects the application range of converter slag. [0003] Most of the elements in converter slag are beneficial components. After slag treatment, it is wid...

AI Technical Summary

Problems solved by technology

The reuse of converter slag is limited by free calcium oxide (f-CaO) and free magnesium oxide (f-MgO) in its composition, because of the corresponding volume change caused by the reaction with water, which in turn affects the application range of converter slag

[0003] The vast majority of elements in converter slag are beneficial components. After slag treatment, it is widely used in agriculture, construction, and environmental protection. At present, there are many ways to treat slag outside the furnace. After slag treatment, it can be used as road construction raw materials, cement powder, and microcrystalline Glass, agricultural phosphate fertilizer, sintering and returning to ore, etc. However, due to the limitation of processing costs and related industry standards, the domestic converter slag reuse rate is less than 30%

How to find a new dephosphorization agent, on the basis of dephosphorization, how to form high-solid phosphorus phase slag, how to optimize the operation of slag splashing to protect the furnace and improve the utilization rate of dephosphorization agent, none of the above patents involves

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