METHOD FOR PRODUCING HIGH-PERFORMANCE, MINERAL-BASED LIGHTENING ADDITIVES

Abstract

The invention relates to a method for producing a high-performance mineral lightweight additive comprising the following steps: (i) preparation of a raw material mixture comprising (in % by mass): - raw diatomite with a SiO2 content ≥ 62% by mass, accounting for 65% to 80%; - raw kaolin clay with an Al2O3 content ≥ 30%, accounting for 15% to 30%; - rice husk accounting for 5% to 10%, wherein which the diatomite and kaolin clay are dried and pre-ground to a particle size smaller than 1 mm; (ii) calcining the raw material mixture at a temperature between 780°C and 820°C until constant weight is achieved; and (iii) cooling the calcined product to room temperature and grinding to obtain a high-performance mineral lightweight additive. In addition, the invention also relates to the additive obtained by the above method. This additive is suitable for mixing with well cement to reduce the density of well cement mortar to the desired level while still ensuring the properties of the mortar and the aggregate obtained from the mortar.