Desilication demanganization method at same time of preprocessing hot metal

Abstract

The invention relates to a method for hot metal pretreatment and desiliconization as well as demanganization at the same time. The method comprises the hot metal pretreatment, wherein, eluant gas is utilized to spray desiliconization and demanganization agent into hot metal by adopting a powder injection method; a changing basicity method is adopted during the process of desiliconization and demanganization treatment; the SiO2 generating speed in the desiliconization reaction is calculated according to the total desiliconization amount and treatment time; the desiliconization slag basicity iscalculated, and the calculating process thereof comprises the following steps: the powder injection treatment time of desiliconization and demanganization is evenly divided into N stages, wherein, N is an integer, and N is more than or equals to 1 as well as less than or equals to 5; at the stage of N, the powder injection rate is adjusted to lead the desiliconization slag basicity in the time segment to satisfy the formula that B equals to (CaO powder injection rate (kg / min)) / (SiO2 powder injection rate (kg / min)+desiliconization SiO2 generating rate (kg / min)), 0.5 to 0.5+1 / N; the temperatureof the hot metal pretreatment ranges from 1280 DEG C to 1400 DEG C. The method can perform the desiliconization and the demanganization at the same time, and also can remove a little phosphorus; the hot metal, the initial manganese content of which is more than 0.3 percent, is performed through the powder injection process in a torpedo tank or a foundry ladle, so as to enable the manganese content of the processed hot metal to be less than 0.1 percent.

Description

A method for simultaneous desiliconization and demanganization of molten iron technical field The invention relates to the technical field of steelmaking technology, in particular to a method for simultaneous desiliconization and demanganization of molten iron pretreatment. Background technique Manganese is a beneficial alloying element in steel in most cases, and manganese is an essential alloying component for the strength of structural steel. Therefore, in the general steelmaking process, the oxidation loss of manganese should be avoided as far as possible during refining, so as to reduce the amount of manganese-ferroalloy added when tapping the converter, thereby reducing production costs. In order to achieve this purpose, the pretreatment of molten iron dephosphorization is widely used at present. A spray gun is used to spray lime-based flux and solid oxygen source iron oxide into molten iron for dephosphorization. The pre-dephosphorized molten iron produces a small ...

AI Technical Summary

Problems solved by technology

During desiliconization of hot metal pretreatment, part of the manganese can also be removed, but it is far from the demanganization requirement required by low manganese steel, for example [%Mn]<0.1

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