Nov 02, 2021 In this paper, the preparation method and reasonable mix ratio of non-calcination brick with rock powder, cement, lime and fly ash ceramsite (FAC) as the raw materials were experimentally evaluated. To better understand the effects of each component on the performance of non-calcination rock powder brick (NCRPB), an orthogonal experimental design was conducted with the Calcination in a rotary kiln is a direct, long-time calcining process. During the process, the phases of the CaSO 4 x H 2 O system can be optimally adjusted. Rotary kilns are used for the calcining natural gypsum. In this process, pre-crushed natural gypsum is calcined in parallel flow with the flue gas.