Calcium-carbonate-containing calcium oxide-based manganese alloy dephosphorization slag, preparation and application method of the same

Abstract

The invention relates to a calcium-carbonate-containing calcium oxide-based manganese alloy dephosphorization slag. The calcium-carbonate-containing calcium oxide-based manganese alloy dephosphorization slag comprises the following components in parts, by weight: 15-30 parts of calcium oxide,15-30 parts of manganese oxide, 35-45 parts of sodium carbonate, and 15-30 parts of fluorite, wherein the particle size D50 of the calcium oxide, the manganese oxide, the sodium carbonate and the fluorite is less than or equal to 10 mm; the preparation method of the dephosphorization slag comprises the following steps that pre-melting treatment on a mixed material is carried out, heating is carried out to 1000-1200 DEG C, and the temperature is kept for 30-50 minutes, the molten slag is poured out, andnaturally cooling is carried out; crushing and screening are carried out on the slag which is cooled to the room temperature, and finally the dephosphorization slag with the particle size smaller than or equal to 5 mm is obtained; and the application method of the dephosphorization slag is provided, when the manganese alloy is smelted, the preheated dephosphorization slag is added in multiple times. The preparation and the application method have the beneficial effects that effects of dephosphorization in the slag is stabilized through the dephosphorization slag, the gas generated by decomposition of the sodium carbonate can play a role in stirring and removing phosphorus slag at the same time, and a kinetic reaction condition is increased, the dephosphorization melting point of the manganese oxide and the fluorite is reduced, the liquidity of the dephosphorization slag is improved, and the better dynamic condition is provided for the dephosphorization.

Description

technical field [0001] The invention relates to the field of ferroalloy refining, in particular to a calcium oxide-based manganese alloy dephosphorization slag containing sodium carbonate, a preparation method and an application method. Background technique [0002] Ferromanganese, as a ferroalloy with large consumption in steel production, is mainly added to molten steel as a deoxidizer and alloying agent in the reduction and refining stage in steelmaking production, so almost all the phosphorus in ferromanganese enters the steel. At present, in addition to the smelting process of manganese-rich slag, which can remove part of the phosphorus in manganese ore, in other processes of ferromanganese smelting, most of the phosphorus in the raw material enters the alloy. The phosphorus content of ferromanganese is mainly controlled by ingredients, and the production of low-phosphorus The dephosphorization of ferromanganese and ferromanganese is receiving more and more attention. ...

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Problems solved by technology

At present, ferromanganese dephosphorization methods are mainly divided into oxidation method and reduction method. Theoretical research shows that the conventional calcium oxide slag system suitable for iron-based melts is difficult to meet the requirements of ferromanganese dephosphorization. Only sodium oxide with higher alkalinity, The dephosphorization of manganese melt can only be realized by barium oxide slag system. The literature "Experimental Research on Dephosphorization of Ferromanganese Melt by BaCO3-based Flux" systematically studied the dephosphorization effect of BaCO3-based flux, and analyzed the effect of slag-based treatment time on dephosphorization. However, the dephosphorization effect has not been studied in depth. From the data provided in the article, it can be seen that ferromanganese cannot be deeply dephosphorized. After dephosphorization, the content of ferromanganese and phosphorus> 0.3%; the literature "Theoretical Analysis of Oxidative Dephosphorization of High Carbon Ferromanganese" compared the feasibility of barium oxide and calcium oxide slag systems for dephosphorization and manganese preservation from the thermodynamic point of view, and concluded that barium oxide slag systems can meet the requirements for dephosphorization and manganese preservation , and analyzed the effects of carbon, silicon, manganese oxide activity in slag, and barium oxide in slag on dephosphorization and preservation of manganese, but only provided a thermodynamic feasibility study, and failed to conduct in-depth research on the actual dephosphorization effect

[0004] From the literature research, the theoretical analysis of ferromanganese dephosphorization is relatively thorough, but there are not many specific dephosphorization effects and methods involved, especially the deep dephosphorization technology of ferromanganese (P<0.1% after dephosphorization, mass percent content) has not been mentioned in the literature, it is necessary to conduct research on this