Study on the dissolution of dolomite sand in converter steelmaking slag

Due to the serious overcapacity of steel production and the low level of steel profitability, the overall steel industry is sluggish, and the cost control of converter steelmaking is particularly important. Slag-forming agent is one of the main costs of converter steelmaking, and the use of low-cost slag-forming agent has become a focus of attention of various iron and steel enterprises. Most domestic enterprises have begun to use low-cost slagging agents such as limestone or limestone for the research and production practice of converter slagging, but no in-depth research has been carried out on the slagging mechanism of these low-cost slagging agents.

Dolomite powder supply

Dolomite sand manufacturers

Scholars from Wuhan University of Science and Technology conducted the dissolution test of raw dolomite and light-burned dolomite in converter steelmaking slag according to the actual demand of using raw dolomite instead of light-burned dolomite for slag making in converter steelmaking. Through scanning electron microscope observation and energy spectrum analysis , comparatively analyzed the dissolution mechanism of raw dolomite and light-fired dolomite, and carried out the production practice of raw dolomite instead of light-fired dolomite to make slag. The results show that the dissolution mechanisms of raw dolomite and light-burned dolomite in steelmaking slag are different. Raw dolomite first undergoes decomposition reaction and fragmentation at high temperature of steelmaking to form MgO and CaO particles, and then dissolves with molten slag. At the same time, due to the stirring effect of CO2 bubbles, the dissolution rate of stone sand is significantly faster than that of lightly burned dolomite. At the converter steelmaking temperature, the decomposition of carbonate in raw dolomite is completed in one step. Using raw dolomite to make slag, the dephosphorization rate of steelmaking is increased from 83.2% to 84.1%, the mass fraction of sulfur increase is reduced from 78×10-6 to 71×10-6, the properties of the final slag are also beneficial to the maintenance of the furnace lining, and the cost of the flux is reduced by 2.98 Yuan/t.