Mica and Its Uses.

The Manufacturer and Builder 8, 1892

There is a greater range of use for ground mica than for the mineral in sheets, and, though the value of that part of the product made use of in this form in small, the many peculiar properties which ground mica possesses render it quite probable that its use will be widely extended. The difficulties to be overcome and grinding mica are considerable, and there are only two or three firms, says one of our London exchanges, engaged in the business at prescut. Eight standard grades of ground mica are made. The coarsest of these are used to give frosted and spangled effects to the fancy grades of wall paper. The medium grades are employed in the manufacture of a lubricant for the journals of milway carriages, for heavy bearings generally, and for the axles of road vehicles. The finest grades are used, in producing a uniform metallic white surface on wall paper. Scrap mica for grinding must be white and as free from specks or colored matter as possible, since any impurities in the scrap will affect, the color and luster of the product. There is considerable consumption of mica on the part of the manufacturers of electrical machinery and likewise for stove purposes. The higher grade micas are used for the latter purpose. The lower grade micas are used by the electrical manufacturers.