GB508929A - Depression of carbonaceous material in flotation - Google Patents

Abstract

508,929. Concentrating ores. AMERICAN CYANAMID CO. Dec. 19, 1938, No. 36959. Convention date, Feb. 1. [Class 82 (ii)] In the concentration by froth flotation of carbonaceous precious metal ores, a dextrine, preferably yellow corn dextrine, is added to the pulp to depress the carbonaceous material. The dextrine may be used in the rougher flotation or, if desired, only in the cleaning of the rougher concentrate. A carbonaceous pyritic gold ore may be ground with yellow corn dextrine, conditioned with soda ash and copper sulphate and floated with pine oil, secondary butyl xanthate and a mixture of sodium diethyl and disecondarybutyl dithiophosphates. In another example, a similar ore is first floated without the use of dextrine and the concentrate either cleaned simply with addition of dextrine or conditioned with dextrine and floated with copper sulphate, more dextrine and secondary butyl xanthate. Alternatively, all of the dextrine may be added in the conditioning step. The cleaned concentrate may be recleaned with further additions of dextrine, copper sulphate and butyl xanthate. A copper-gold ore containing graphite may be conditioned with dextrine, secondary butyl xanthate and a mixture of sodium diethyl and disecondarybutyl dithiophosphates and then floated with addition of dicresyldithiophosphate and a synthetic frother consisting of a mixture of higher aliphatic alcohols. The flotation of a carbonaceous silver ore is also described.