Process for increasing the zeolites content of by- products of 'tufa stone' block quarries

摘要

Scrap, waste and sawings from "tufa stone" quarries are rich in zeolites (cabasite, phillipsite +/- analcime). A 1st concentrate of zeolites is obtained from the various types of waste, removing black slags and (inert) decimetre-sized larva inclusions on the basis of their dark color. A second concentrate is obtained by differential grinding (+/- abrasion). A good concentration of (very friable) zeolites which reaches an optimum in the fractions 100 μ is obtained in the sand fractions. Zeolites are cation exchangers, molecular sieves, antacids, etc., and are used as such for the purification of water, stockfarming slurries, feedstuffs, natural fertilizers and many other uses.