Calcium, barium or strontium carbonate granulation - with binder addn. and without contact by refractory material

摘要

In granulated calcium, barium or strontium carbonate prodn. by hot granulation of the material with additive addn. and opt. subsequent high temp. treatment, the novelty is that the material is granulated in the presence of a binder additive either by application of mechanical forces or by accretion and is not contacted by inorganic refractory material during the granulation and the opt. high temp. treatment. Also claimed are (i) granulated calcium, barium or strontium carbonate, which is free from inorganic refractory materials, contains 0.05 - 5 wt.% binder (pref. alkali metal hydroxide, waterglass, silicic acid ester, starch native potato starch, dextrim, cold soluble potato or wheat starch, polyvinyl alcohol, sodium polyacrylate or their mixts.) and is obtained by the above process; and (ii) glass prodn. using granulated barium or strontium carbonate obtained by the above process. USE/ADVANTAGE - The granulated carbonates (esp. BaCO3 and SrCO3) are used in the glass industry, e.g. for mfg. x-ray absorbing front panels for televisions. They are produced simply and are absolutely free of inorganic refractory material impuriti