Concentration of low-grade chromite ores.

Chromite has long been considered as one of the more important strategic raw materials. Its indispensability in the manufacture of alloys makes it vital to the nation's industrial life. The great bulk of the mineral is consumed in the form of ferrochrome, an alloy containing 60 to 70 per cent chromium, which is used in making alloy steels. Pre-war time specifications for ferrochromium required that it should contain 68 to 69 per cent chromium. Since 194l these specifications have been lowered to between 60 and 63 per cent chromium so that low-grade ores could be utilized. [...