Abstract
The main reagent for desulfurization in steelmaking is lime. This is due to both the low cost of raw materials and rather simple technology of its production. The efficiency of steel desulphurization with lime is determined by its quality. In domestic practice, the quality of lime is usually assessed by the content of active CaO, which depends on the chemical composition of limestone and the degree of completeness of calcium carbonate dissociation. At the same time, it is more correct, from the point of view of lime behavior in steelmaking processes, to assess the lime quality by its activity degree. The most accurate way to determine the degree of lime activity is the acid-base titration method. One of the options for increasing the degree of lime activity is to increase its open porosity, which is possible when burning at high pressure in an inert gas environment. In this work, the influence of limestone burning technology at high pressure on the degree of lime activity, as well as the influence of lime activity on the results of steel desulfurization, was studied. The results show that with increasing inert gas pressure during limestone burning (up to 0.3 MPa) the degree of lime activity increases, and the structure changes from fine-porous to large-porous. It was found that with an increase in the degree of lime activity, a practically linear increase in the degree of steel desulphurization is observed: by 0.72% for each percent increase in lime activity.
Keywords:
lime, burning technology, burning pressure, lime activity degree, desulfurization, large pore structure