— dust-like quartz (mountain flour, quartz Melita, dust-like silicon dioxide) — the mealy mass of fine quartz, usually perfectly white color. Consists of angular grains of quartz with chalcedony impurity, fell down, carbonates and clay minerals. Losses when calcinating 0,55 — 1,42%. Marshalit differs in high dispersion and low content of oxides of iron. The prevailing fraction (St. 80%) are grains less than 0,01 mm. Ud. century 2,61 — 2,65, the volume weight 1,14, volume of emptiness in a natural marshalit reaches 60%. Ud. a surface of 1130 — 1500 cm2/g, fire resistance 1650 — 1710 °, heat conductivity at 20 ° 1,67 • 10 ~ 3, at humidity in 21 weights. % 22-10 "5 W / sm-grad, and at 344 ° 1,07-10 ~ the 4th kal/sm-sec.-hail. Marshalit easily gives in to enrichment by an otmuchivaniye and air separation with allocation of monomineral fractions and simultaneous decrease in maintenance of Fe203 to 0,02%. Khimich. the maintenance of Fe203 can be reduced by enrichment to 0,004%. Sometimes marshalit it turns out artificially — a grinding of quartz sand.
Application of a marshalit is based on his Khimich. the structure coming to composition of quartz, and high dispersion at the low content of oxides of iron. Marshalit is of interest to all branches of a prom-sta where the low-ferruterous quartz raw materials in thin crushing are required: as a filler of rubbers (especially electroinsulating) and plastic; in glass a prom-sta — for cooking of unpainted glass; as forming material or paint for casting molds; instead of quartz at production of porcelain and faience; as an abrasive for grinding of glass, marble etc.; for production of a lightweight dinasovy ogneupor and fire-resistant putties; for receiving silicate of sodium (soluble glass), a silikaltsit, acidproof cement, autoclave construction materials; as micron - polnitell concrete; as a filler of special grades of paper, paints, glue etc.