Process for the recovery of cassiterite from ores

摘要

In a process for the recovery of cassiterite from an ore, the sulphides (unless present in quantities less than 4 per cent. of the tin present) are first floated and the cassiterite then floated in a liquor having a pH value not higher than 6 with a collector comprising a compound containing in a straight hydrocarbon chain, or a straight portion of a hydrocarbon chain, more than 6 carbon atoms and containing also an So4 or So3 group to which is attached an invisible hydrogen or metal atom. The sulphides are floated by the use of a xanthate type of reagent and this flotation may be followed by one in an alkaline solution using a reagent of the type described above. The cassiterite flotation may be carried out in two stages in the presence of a collector such as sodium cetyl sulphate at a pH value of less than 4 and the concentrate from the rougher flotation may be leached with acid before the cleaner flotation. The grade of the concentrate may be improved by the addition of sodium silicate. Lead salts may be used as depressants for topaz. Examples of the collector include the following or their salts: primary or secondary alkyl sulphuric acids, anathyl sulphuric acids, alkyl sulphonic acids, sulpho succinic acids, aryl sulphonic acids, sulphonated ethers, N-acyl taurines 2-acyloxy-1 ethane sulphonic acids, carbalkoxy ethane sulphonic acids or glycerol having one primary alcohol esterified by a fatty acid and the other with the carboxyl portion of sulpho acetic acid. Specification 405,163 and the corresponding German Specification 659,431 are referred to.