Compound dephosphorization agent with converter slag as raw material and preparing method thereof

Abstract

The invention discloses a molten iron pretreatment compound dephosphorization agent with converter slag as the raw material, and the compound dephosphorization agent contains the following raw materials by weight: 45 to 55 percent of converter slag, 3 to 5 percent of quartz sand, 22 to 34 percent of steel-rolling iron sheet, 3 to 6 percent of bauxite, 10 to 14 percent of soda and 0 to 5 percent of fluorite; the raw materials meeting the ingredient demands are evenly mixed according to the proportions after being crushed, and then the product with the diameter being 20 to 50mm is produced after ball-milling, screen separation, palletizing and drying. The compound dephosphorization agent realizes cyclic utilization of the converter slag which accounts for 45 to 55 percent, thus reducing the produced slag amount in the steel-making process and the environmental load; the converter slag contains plenty of CaO and FeO, which can reduce consumption of lime to a certain degree, thus increasing the metal yield rate and reducing the steel-making cost; the compound dephosphorization agent has low melting point, slag can be formed fast, the liquidity is good, thus shortening the treatment time, the dephosphorizing efficiency is high, and the dephosphorized final slag has low alkalinity and low melting point.

Description

technical field [0001] The invention relates to a molten iron pretreatment composite dephosphorization agent used in the field of metallurgy and a preparation method thereof, in particular to a molten iron pretreatment composite dephosphorization agent using steelmaking converter slag as a basic raw material and a preparation method thereof. Background technique [0002] In recent years, my country's iron and steel industry has developed rapidly, and the output of steel has increased year by year. The output of metallurgical slag derived from this has also increased significantly. The annual output of converter slag alone has reached tens of millions of tons. The cumulative stockpiles and newly added converter slag are increasing day by day, which not only causes a serious waste of resources, but also occupies a large area of ​​land and pollutes the surrounding environment. Since the utilization of converter slag still lacks practical and effective ways, its comprehensive ut...

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Problems solved by technology

[0004] At present, some metallurgists have studied the dephosphorization of molten iron with lime-based dephosphorization agent combined with converter slag, but most of them only add powdery or massive converter slag to solid synthetic slag, so there are inevitable shortcomings : (1) Converter slag has high basicity and high melting point, and the dephosphorization agent takes a long time to dissolve slag after adding it, and the dephosphorization rate is low, which increases the time and temperature drop; (2) The solid synthetic dephosphorization agent containing converter slag is formulated A large amount of active lime is added, which is easy to absorb moisture and is not conducive to storage and transportation; (3) Due to the large difference in particle size and density, component segregation is easy to occur, resulting in unstable performance of the dephosphorization agent and sometimes causing phosphorus reversion

[0005] The premelted dephosphorization agent containing converter slag has not been widely used because of complicated processing and high cost.

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