Method for removing free calcium oxide and magnesium oxide in converter steel making slag

Abstract

The invention discloses an energy-saving and efficient method for removing free calcium oxide and magnesium oxide in converter steelmaking slag. The method includes: placing the converter steelmaking slag in a jaw crusher for crushing; sieving crushed steelmaking slag according to three different grain sizes; mixing the steelmaking slag of different grain sizes according to a mass percentage; starting a heating program of a reaction furnace to remove calcium oxide and magnesium oxide; and detecting removing condition. By the method for free calcium oxide and magnesium oxide in the converter steelmaking slag, converter steelmaking slag resources can be fully utilized, and environmental pollution can be reduced. The reaction furnace used can be a rotary kiln, blast furnace waste gases are utilized for heating, so that the slag can fully react to remove the free calcium oxide and magnesium oxide in the slag. The method for free calcium oxide and magnesium oxide in the converter steelmaking slag is simple in operation, low in investment and good in removing effect, occupied space of treatment process is saved, and water is saved.

Description

technical field [0001] The invention relates to a method for treating waste slag from converter steelmaking. In particular, it is a method for dissolving free calcium oxide and magnesium oxide in converter steelmaking waste slag. Background technique [0002] With the development of the iron and steel industry, the discharge of steel slag is also increasing year by year. A large amount of steel slag is discarded and piled up, occupying farmland and polluting the environment, which has become a major public hazard to society. The comprehensive utilization of steel slag is particularly important. When fCaO and fMgO in steel slag meet water, they hydrate to form Ca(OH) 2 , Mg(OH) 2 Volume expansion is very easy to expand in hardened cement paste, resulting in cracking of concrete engineering, roads, and building materials mixed with steel slag. Therefore, steel slag must be effectively treated before use to fully digest fCaO and fMgO before use. Chinese Patent Publication ...

AI Technical Summary

Problems solved by technology

Liquid molten steel slag can be directly filled into tanks for hot stuffing, which can make full use of the heat of the slag itself for self-decomposition and pulverization. The repeated process of water spraying and hot stuffing can further promote this self-decomposition process. This method is complicated to operate, and the operation is safe if the temperature is too high. low, but also consumes water resources

Chinese Patent Publication (Announcement) No.: CN101397595, title: a method for hot stuffy treatment of molten steel slag, which is characterized in that it comprises the following steps: 1) pad dry slag, and evenly pad loose steel slag on the bottom of the hot stuffy device; 2) dump Turn over the molten steel slag, tipping the molten steel slag in the hot stuffy device; 3) turning over the steel slag, and spraying water mist to solidify the surface of the steel slag; 4) spraying, spraying the steel slag with water mist until the temperature of the steel slag is Stop spraying at 70-85°C; 5) Digestion, cooling down the steel slag after stopping spraying, until the f-CaO and f-MgO in it are hydrated into Ca(OH) 2 , Mg(OH) 2 At this time, the product is obtained; the temperature at this time is lower than or equal to 65 ° C, the method is complicated to operate, low in safety, and consumes water resources

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