Opaliform procellanite and process for the preparation thereof.

摘要

The present invention provides high grade opaliform porcellanite having a purity of at least 80% active silica. The invention also provides a process for the production of a high grade opaliform porcellanite having a purity of at least 80% active silica comprising grinding and screening porcellanite rock to form granules having an average diameter of between about 0.6 and 18 mm and then subjecting said granules to wet disintegration to remove soft clays and limestone and gravitic separation to separate the lower density opaliform active silica from higher density impurities intermixed therewith.