A method for desiliconizing molten iron for stainless steel smelting

Abstract

The invention provides a method for desiliconization of molten iron for stainless steel smelting, which includes the following steps: Step 1: preparation of blast furnace molten iron: adding the laterite nickel ore to the blast furnace after batching and sintering for smelting, and ensuring that the tapping temperature of the blast furnace is ≥ 1350°C; Step 2: Transportation: Transport the high-temperature nickel-containing high-silicon molten iron from the blast furnace to the desiliconization converter in the form of "one pack to the bottom" or "mixed iron furnace"; Step 3: Treat nickel-containing high-silicon in the desiliconization converter Desiliconization, decarburization, dephosphorization, and desulfurization of hot metal are carried out, and the hot metal is desiliconized by top-bottom double blowing. After desiliconization, the mass percentage of silicon in the hot metal is not more than 0.20%; Step 4: final product smelting: blowing After the completion, the semi-steel from the desiliconization converter is charged into the AOD furnace, and the alloy is added in the AOD furnace at the same time, and the final smelting of stainless steel is completed. This desiliconization process requires low Si content in molten iron, provides sufficient reaction space for desiliconization, effectively prevents splashing, and creates good kinetic conditions for desiliconization, and can also perform dephosphorization and desulfurization operations.

Description

technical field [0001] The invention relates to a method for desiliconizing molten iron for stainless steel smelting, in particular to nickel-containing and high-silicon molten iron produced by treating laterite nickel ore. Background technique [0002] With the rapid development of the stainless steel industry, the demand for metal nickel continues to increase. However, nickel sulfide ore resources are increasingly scarce, making laterite nickel ore the main source of nickel supply in the future. Laterite nickel ore accounts for 72.2% of the world's land-based nickel resources, but the nickel it produces only accounts for 42% of the world's nickel production. Using laterite nickel ore to produce nickel iron water provides a cheap nickel source for the rapidly developing stainless steel industry. It is the use of laterite nickel ore efficient access to resources. The content of silicon in blast furnace ferronickel water produced from laterite nickel ore is very high, some a...

AI Technical Summary

Problems solved by technology

Combined with the characteristics of high content of nickel-containing molten iron [Si] and [Ni], the melting point of nickel is high. High nickel content leads to high tapping temperature of blast furnace. Limited desiliconization capacity; desiliconization in molten iron tanks is prone to splashing

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