Desulfurization method of low-phosphorus low-silicon molten iron

Abstract

The invention relates to a desulfurization method of low-phosphorus low-silicon molten iron. The method comprises the following steps that after tapping is finished, a ladle car runs to a wire feedingposition, the temperature is controlled at 1450 DEG C-1550 DEG C, a bottom blowing nitrogen system is turned on, the nitrogen flow is 60-100 NL per minute, lime particles are added to the liquid level of the molten iron, and the addition amount is 1.5-4 Kg per ton of molten iron, the ladle bottom blowing nitrogen system is closed after lime melting, and a thermal insulation agent is added, then the passivated packed wire of magnesium is fed at the wire feeding speed of 35-40m per minute, the wire feeding amount is 0.3-0.6 Kg per ton of iron, the wire feeding needs to be finished once, after the wire feeding is finished, the ladle bottom blowing nitrogen system is started, and the bottom blowing flow is 60-100 NL per minute, and the bottom blowing is stopped after 3-5 min. According to themethod, the desulfurization effect is better, and the desulfurization rate can reach up to 92% or above.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a high-efficiency, low-phosphorus, low-silicon molten iron feeding line molten iron desulfurization method. Background technique [0002] In the production of smelting reduced iron, due to technological reasons, the initial sulfur content of molten iron is as high as 0.06%, phosphorus: 0.025-0.035%, silicon: 0.15-0.25%, and ordinary blast furnace molten iron phosphorus (0.10-0.25%) and silicon content (0.35-0.65 %) are relatively low, and molten iron cannot be directly used for steelmaking or casting. Low phosphorus and low silicon also make slagging difficult and desulfurization difficult. In order to reduce desulfurization cost and improve operation efficiency, a simple and efficient molten iron desulfurization device is needed to desulfurize molten iron. Soda ash (Na 2 CO 3 ) or the KR method, but because a large amount of white smoke and Na slag are produced in th...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the above technical problems, the present invention provides a high-efficiency low-phosphorus and low-silicon molten iron desulfurization method, which can solve the problems of high sulfur content in low-phosphorus and low-silicon molten iron, difficulty in removing desulfurization slag, polluting the environment and low desulfurization rate. Foundry provides high-quality hot metal