GB406018A - Improvements in or relating to the treatment of mineral sand for the separation of one constituent therein from another - Google Patents

Abstract

Zircon is separated from other constituents of mineral sands by treating the sand to produce selective oiling of the zircon particles and then forming a froth containing the oiled particles. The froth may or may not float on the surface of the pulp and in the latter case is separated from the unoiled particles by passing the pulp over shaking tables or jigs. A sand containing zircon, rutile, monazite, ilmenite, garnet, quartz, cyanite, &c., is preferably first treated by magnetic separation to remove the ilmenite and most of the monazite and is then washed on shaking tables to remove the quartz. The residual sand is then agitated, preferably with a very dilute soap solution and an oil such as pine oil, eucalyptus oil, cresol, or a higher alcohol, to form a froth. A thicker oil or fat such as oleic or other unsaturated fatty acid, olein or a similar glyceride, phenol or cresol, or sulphonated derivatives of any of these substances is preferably added to cause flocculation of the oiled zircon particles, the thicker oil or fat being preferably dissolved or dispersed in an alkali such as ammonia or caustic soda, or in an alcohol, or in p the frothing oil. To prevent oiling of the rutile, monazite, &c., the pulp is preferably made alkaline and the sand may be treated with an acid and then washed with water prior to agitation in the oily soap solution. The flocculation of the zircon particles may be improved by the addition of small amounts of soluble salts of metals such as magnesium, zinc, lead, copper, or the alkaline earth metals, which produce insoluble soaps. The froth may be formed in a rotating cylinder provided with agitating baffles or riffles, from which the pulp is passed over a small shaking table, the froth of oiled zircon particles being washed off by a slow current of water, or alternatively the froth may be formed in a sub-aeration flotation machine. The zircon concentrate obtained in either case may be cleaned by washing with acid and then with water and retreating to produce a froth of the zircon particles. The soap used in the frothing process may be for example sodium oleate, sodium palmitate, sodium stearate, or the corresponding potassium salts, or the alkali salts of sulphonated derivatives of unsaturated alcohols, such as sodium oleylsulphonate. In some cases the soap may be omitted and the zircon froth produced by a mixture of a frothing agent and olein, oleic acid, or other fatty or tarry oil. Specification 406,043 is referred to.