METHOD FOR PRODUCING CARBONATE-CONTAINING FILLER FROM NATURAL RAW MATERIALS Russian patent published in 1997 - IPC

FIELD: chemical industry for production of polymeric composites, paintwork materials and drilling fluids. SUBSTANCE: method resides in subjecting natural feedstock to pretreatment, followed by drying finished product. Inventive novelty of proposed invention resides in following features: as natural feedstock, method employs so-called "sapropel", i.e. silt excavated from lake bottom and having calcium carbonate content (based on CaCO<Mv>3<D> content in ash) 0.1-53 wt.-%. Drying is carried out either naturally, or by supplying heat at 46-520 C up to moisture content at most 5.0%. Pretreatment may comprise freezing of "sapropel", followed by natural drying up to moisture content at most 65 wt.-%, or by mixing with water up to sapropel concentration 1-50 wt.-% and by filtering and homogenizing mixture thus-obtained. Alternatively, "sapropel" can be pretreated by removing from it alien inclusions, followed by filtering and homogenization. Once dried, "sapropel" can be comminuted and/or fractionated down to particle size 1.0-100 mcm. Prior to, and after mixing with water feedstock must be comminuted. EFFECT: effective method for commercializing hitherto unused, naturally occurring cheap raw material. 7 cl, 5 tbl