Evaluation of the output of lime is made for three options for the use of Ferroalloy gas: when you use the physical heat of the gas; when using the chemical energy of the gas and the location of the reactor after scrubbing; when sharing of sensible heat and chemical energy of the gas. As a result of the calculation of the expected yield of lime, it was found that the use of Ferroalloy gas for the production of lime can fully provide or at least compensate for the deficit of lime in the production of steel. The technology of calcination of limestone with Ferroalloy gas is presented in the form of a cycle synchronized with the smelting of steel, including, in accordance with the gas outlet from the layer and their alternation with pauses of inter-blowing periods. The preliminary technological characteristics of firing obtained as a result of theoretical analysis are used for further experimental and theoretical studies.