Process for the preparation of granulated abrasives from fused or sintered refractory inorganic hard substances having a high grain toughness
AssigneeDynamit Nobel Aktiengesellschaft
InventorsGerd-Edzard Bockstiegel, Manfred Neidhardt, Gerhard Rehfeld, Werner Umlauf
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Abstract
A process for the manufacture of granular abrasives having improved grain toughness from refractory, inorganic hard substances which comprises crushing a lump or block of said refractory inorganic substance, thereafter subjecting the resultant grains to a grind sorting process such that substantially only the porous grains, grains containing flaws or coarsely crystalline grains are comminuted and separating them in the ground condition from the balance of the material.
Claims10
A process for preparing an abrasive composition which consists essentially of crushing an alumina block or lump having an alumina content of 40-100% by weight and a zirconium content of 0-60% by weight to obtain a crushed mass;
- subjecting said mass to a grain shaping treatment by blasting the crushed material in an apparatus having at least one baffle plate;
- ball milling the crushed mass employing a grinding medium of balls whose diameter is between 3 and 8 cm. while revolving the ball mill at a rate of between 8 and 40 rpm, the weight of the milling medium being between 1.0 and 4.0 that of the weight of the crushed mass while carrying out the ball milling for a period of between 0.5 and 4.0 hours and thereafter separating particles from the so ball milled composition which have a particle size of 8-24 mesh from the balance of the material.
Dependencies are inferred from the claim text.