... -manganese, silicon, chromium), and for the flux. Quality can be prepared pure crystalline silicon. Crystalline silicon is the main raw material ... . Sand mixed with asphalt paving, quartz calibration materials can be made of Portland cement.4) Chemical industry: silica can ... .5) the abrasives industry: quartzite and quartz sandstone can be made to the grindstone, whetstone, and sandpaper, and carbonated ...