Abstract: A material containing corundum crystals from 5 to 350 microns in size and any one of the additions: spinel, anorthitic glass, cordieritic glass, or a mixture of spinel and either of said glasses. Said addition amounts to 1.5-7.5% by mass of the abrasive material and is spread between the corundum crystals in the form of interlayers less than 20 microns thick.

Abstract: A process for the production of sodium aluminate comprising drying an aluminate solution containing from 45 to 350 g/l of caustic Na.sub.2 O with a molecular ratio of caustic Na.sub.2 O to Al.sub.2 O.sub.3 from 1.1 to 1.8 in a fluidized bed of solid particles at 250.degree.-400.degree. C. of sodium aluminate using a gas heated to 750.degree.-950.degree. C. containing no carbon dioxide as a fluidizing medium and a heat carrier in an amount from 2000 to 25000 nm.sup.3 per 1 m.sup.3 of aluminate solution; feeding said aluminate, solution for drying by atomizing it at a velocity from 25 to 35 m/s thereby obtaining sodium aluminate in the form of pellets of a size from 0.5 to 8 mm with a bulk weight from 1.2 to 1.4 t/m.sup.3 completely soluble in water and alkaline solutions, with a maximum content of hygroscopic moisture of 0.3% by weight and a maximum content of water of crystallization of 5% by weight.