The Art of Talc Flotation for Different Industrial Applications

Abstract

Talc has found a steadily increasing number of uses such as cosmetics, steatite and cordierite ceramics, for pitch control in the paper industry and as a reinforcing filler in rubber, etc. In this research, the amenability of some Egyptian carboniferous finely disseminated talc ores to beneficiation by flotation was investigated on laboratory scale. The original talc sample is characterized by low MgO content (25.40%), low SiO 2 (45.71%), high CaO content (6.32%) and high L.O.I. (11.35%), indicating its low grade. Attrition scrubbing of the crushed ores was found to be an unconventional process, not only for fine talc production, but also for proper separation of the harder carbonaceous gangue. Talc pre-concentrates, less than 0.074 μm, were prepared by attrition scrubbing in the laboratory having 8.40% L.O.I. with a yield reaching 74.70%. Cleaner talc concentrate with L.O.I. content averaging 6.70% was obtained by flotation in the presence of Aerofroth 71 with a yield reaching 64.71%. This was relatively improved by the use of a selective (quaternary amine) talc collector and in presence of a selective carbonate depressant (soda ash). Flotation of the fine ground talc (less than 22 μm) produced a talc concentrate assaying 6.90% L.O.I. with a yield recovery of 62.91%. However, different talc concentrates obtained by just natural floatability or by the use of small dose of Aerofroth 71, or by the application of quaternary amine in presence of carbonate depressant, satisfy the requirement of paper coating, ceramics production, functional filler, and pharmaceuticals applications. Tailings could also be used in carpets, roofs, and tiles production industries.