quartz grades

QUARTZ POWDER Natural moulding sand contains variable amount of clay, which acts as bond between the sand grains. This sand, therefore, posse strength, plasticity and refractoriness to varying extend depending upon the clay minerals present. When it contains a greater amount of clay, it is blended with river sand, which is relatively clay free so as to get the optimum properties desired in the sand mixture. Washed grains shall be mostly sub-angular to rounded shape. As far as possible, the sand shall be free from gravel. Natural moulding sand for use in foundries shall be of three main grades, namely, A, B and C with respect to clay content. Grade: Clay % -A: 5 to 10 -B: 10 to 15 -C: 15 to 20 According to the grain size of moulding sand, each main grade shall be divided in to II sub-grades as indicates below: Grain Size Distribution of Molding S and Grade Fraction retained on I. S. Sieve (m ) % Minimum 850 / 425 850 : 600 and 425 60 600 / 300 600 / 425 and 300 60 425 / 212 425 / 300 and 212 60 300 / 150 300 : 212 and 150 60 212 / 106 212 : 150 and 106 60 150 / 75 150 : 106 and 75 60 850 / 300 850 : 600 : 425 and 300 60 600 / 212 600 : 425 : 300 and 212 60 425 / 150 425 : 300 : 212 and 150 60 300 / 106 300 : 212 : 150 and 106 60 212 / 75 212 : 150 : 106 and 75 60 For example, natural moulding sand falling under grade ‘A’ with respect to clay content and grade 850 / 425 according to its grain size distribution, shall be designated as grade A 850 / 425. Add to Enquiry Basket

QUARTZITE Quartz is mainly used in silicon alloys and ceramic industries, though at times it is also used in the manufacture of glass. Quartzite is used in the manufacture of silica refractories and as a flux in iron and steel industry, silica sand is mostly used in the glass, sodium silicate industries and foundries. The BIS has prescribed specifications for use in glass (IS: 28-1980) and foundry industries (IS: 1987 – 1974) Glass Industry: Four grades of glass making sands are prescribed by the BIS for making glass. Grades: Special grade For the manufacture of high-grade colorless glass, such as crystal glass, tableware and decorated ware. Grade-I For the manufacture of decolourised glassware, such as containware, lampware, etc. Grade-II For the manufacture of glassware, where a slight tint is permissible, and Grade-III For the manufacture of under-colonised some coloured glasses. Size The sizes of the grains constituting the material shall be with in the following limits: Percentage by weight 1 Retained on 1mm sieve Nil 2 Retained on 600 micron IS sieve (max.) 1 3 Passing through 600 micron IS sieve but retained in 300 micron IS sieve (max.) 50 4 Passing through 125 micron IS sieve (max.) 5 Chemical: The chemical compositions of the four grades of sand shall be as follows. This does not cover silica sand used for optical and other special glasses. These requirements shall be as agreed to between the purchaser and the supplier. Physical: The physical specifications of silica sand specifies that silica sand shall be fairly free from contamination like clay material, pebbles and other extraneous matter. The sand should not contain more than 4% moisture. Specifications for by user Industries: The natural silica sand is the most preferred material in a glass industry, but in some cases where the glass plants are located far away from silica deposits, crushed quartz is also used. For use in glass industry the silica sand must be uniform in chemical composition, size and shape of grains. Uniform grain size, promotes even melting in the glass tank. The sand should not be coarser than 20 or 30 mesh nor finer than 100 to 120 mesh. Very fine sand may be carried away by draft in the melting furnace. Both angular and rounded grains are used in the glass trade. As a general rule, the grains should be angular rather than rounded, because they melt more readily than the rounded ones. Silica sand usually contains small amounts of iron oxide, alumina, chromium, magnesium oxide, calcium oxide, potassium oxide because it imparts coloration to the glass.