Low-energy integrated technology for processing underburnt lime into anhydrite cement

A complex structure-controlled method for processing underburnt lime is that this substance reacts with sulfuric acid at a temperature of 45 °C, and as a result two end products are obtained – filtrate and anhydrite. This method makes it possible to control the formation and growth of calcium sulfate crystals to the required size, due to which it is possible to obtain anhydrite cement with the desired properties. With optimum parameters for underburnt lime processing, it is possible to obtain anhyd rite with a MgSO4 content of no more than 0.21 wt%. Combined grinding of synthetic anhydrite with activator additives makes it possible to produce anhydrite cement with a strength of up to 28.5 MPa. The integrated character of the proposed processing method is due to the potential of using the filtrate formed at the stage of separating the suspension of synthetic anhydrite. A method has been proposed for involving the filtrate into economic circulation by neutralizing it and subsequently using it as a microfertilizer in agricultural production.

Author: M.A.Komarov,, N.G.Korob, V. Likhavitsky

Section: Equipment and technology

Keywords: lime-mud, integrated processing technology, structurecontrolled method, synthetic anhydrite, filtrate, anhydrite cement