Molten iron desiliconization agent with high-ferric red mud as matrix and application method thereof

Abstract

The invention discloses a molten iron desiliconization agent with high-ferric red mud as a matrix and an application method thereof. The molten iron desiliconization agent comprises, by mass percent,70%-90% of high-ferric red mud and 10%-25% of magnesium slag. The binary basicity of the desiliconization agent is controlled within 0.6-1.2. The high-ferric red mud comprises 35-55% of Fe2O3, 10-20%of Al2O3, 5-15% of Na2O, and the balance SiO2, TiO2, CaO and impurities. The magnesium slag contains calcium oxide greater than or equal to 55%, magnesium oxide greater than or equal to 6% and silicondioxide less than or equal to 35%. Before or when blast-furnace tapping, the dry molten iron desiliconization agent is added into a hot metal ladle at 20-40 kg per ton of molten iron.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a molten iron desiliconization agent based on high-iron red mud and a using method thereof. Background technique [0002] Red mud is the solid waste that is incidental to the production of alumina in alumina plants. Generally, 1 to 1.8 tons of red mud will be produced for every ton of alumina produced. In 2015, the amount of red mud piled up in my country has reached more than 300 million tons. The storage of red mud not only occupies a large amount of land, pollutes the environment, but also poses serious safety hazards. In addition to Al, Fe, Si, red mud also contains a certain amount of scattered elements such as Ga, Sc, In and Na 2 O, especially the discharged red mud produced by the Bayer method, the iron content is generally between 30% and 60%, so this kind of high-iron red mud has a high recycling value, but because the alumina in the high-iron red mud...

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Problems solved by technology

[0010] The shortcomings of the above patents are that although the above two methods use the rotary hearth furnace as the production equipment, although the direct reduction process of the rotary hearth furnace can effectively treat high-iron red mud and recover valuable elements, the production cost and equipment of the rotary hearth furnace production process High maintenance cost, not conducive to mass production

[0011] Chinese Patent Application No. 201410176170.5 (a method for recycling high-iron red mud as a steelmaking slagging agent / dephosphorizing agent) discloses a recycling and reuse of high-iron red mud as a steelmaking slagging agent / dephosphorizing agent method, the present invention is to mix the air-dried and ground red mud with lime in a mass ratio of 1:0.6-0.8, and use it as a slagging agent / dephosphorization agent for steelmaking. After the red mud is mixed, pour it into a dry pot with molten iron, and keep it warm with the molten iron at 1350-1400°C for 1 hour to complete the dephosphorization and silicon experiments. The dephosphorization rate can reach more than 76%, and the silicon content of the molten iron is reduced. Recycling and utilization of red mud has been realized, but the on-site production process is fast-paced, and hot metal pretreatment desiliconization and phosphorus processes (the whole process is generally within 10 minutes) and the converter steelmaking process (the whole process is generally within 20 minutes) are required to be fast The time is short, the method of desiliconization and dephosphorization of red mud cannot meet the production needs of steel plants

In this method, because a certain amount of carbon-containing substances are added to the ingredients, the iron oxide in the red mud has a high iron recovery rate, but the red mud clumps have insufficient oxidative properties and the desiliconization ability of molten iron pretreatment is low.

And because the carbon powder is added to the pellets, it is easy to cause the iron oxide and carbon in the pellets to react violently in the molten iron, generating smoke and affecting the operating environment

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