Technology of Composites Based on Kul’-Yurt-Tau Pyrophyllites

Abstract

The basic technical characteristics of composites based on pyrophyllite and raw rocks from the Kul’-Yurt-Tau deposit and using phosphate binders are determined. While these materials have satisfactory strength their thermal expansion and thermal conductivity are low while the frost resistance and thermal stability are high. Such materials can be recommended as refractories and building materials for use at temperatures to 1250 – 1350°C depending on the composition of the initial batch. The technology for obtaining these materials is described. Parts and refractory mixes have found applications at certain enterprises. An analysis of published data and research [1 – 3] has shown that in a number of cases it is best to use pyrophyllite rock as an initial material in the production of ceramic materials for fabricating parts for different applications. In the process, the possibilities of rocks from the Kul’-Yurt-Tau (Bashkortostan) and Ovruchskoe (Ukraine) deposits were compared. The general technology for obtaining parts included the following operations: preparation of the initial material, preparing batch and batching, preparation of molding mix, parts molding, drying and heat-treatment of parts and sorting and warehousing finished products. The objective of the present work was to optimize the technology for obtaining composites based on pyrophyllite raw material and phosphate binders as well as to determine the basic technical characteristics of the materials obtained with respect to their applications in actual production. Preparation of initial materials. Portions of samples were obtained from deposits of quartz-pyrophyllite rocks from the Kul’-Yurt-Tau deposit (QPPS) without the bulk component from different sections distributed over height and areas, taking account of pieces with the required size and color. The rock delivered in the form of rubble was crushed in two stages: primary crushing to about 50 mm size in a SM-166 jaw crusher from the Vyksunskii plant followed by secondary crushing in a jaw crusher (Modis NOT, JSC, in Rybinsk); this gave 0.5 – 3.0 mm particles.