Improvements in or relating to methods of concentrating ores

摘要

The separation of acidic materials from other ore constituents by flotation, stratification, tabling, and like processes is effected in the presence of an alkyl or acyl alkylene diamine of the formula or or a salt thereof, where y is an integer from 2-12, R is hydrogen or an alkyl radical, R1 is an alkyl radical of 8-30 carbon atoms or a carboxylic acyl radical of 8-32 carbon atoms, R2 is hydrogen, an alkyl radical of 8-30 carbon atoms or an alkylol-ester or aralkyl radical, R3 is an acyl radical of 8-32 carbon atoms, and R4 is an alkyl, alkylol, alkylol-ester or aralkyl radical. The N-acyl compounds may be prepared by reaction of fatty acids, their esters or acyl halides with alkylene diamines, for example from myristoyl chloride and ethylene diamine in acetone or from coconut oil fatty acids and tetramethylene diamine at 200 DEG C. The N-alkyl derivatives may be prepared from alkylene diamines and alkyl, alkylol, alkylol-ester or aralkyl halide, e.g. from myristyl bromide, propylene chlorhydrin or cetyl chlor-acetate, and an equimolar amount of ethylene diamine or from lauryl bromide with half the molar equivalent of propylene diamine. They may be further acylated, for example N-octyl propylene diamine is reacted with coconut oil fatty acids, N-ethyl ethylene diamine with myristoyl chloride, and N-lauryl tetramethylene diamine with acetic anhydride. Saturated, unsaturated or hydroxy fatty acids may be used for the acylation, preferably those of at least 9 carbon atoms and especially mixtures thereof obtained from fats and oils, and acids such as talloel and naphthenic acid. The free bases or their salts such as hydrohalides, formates, acetates, p-toluene sulphonates may be used. They are particularly useful in the separation by froth flotation of silica or silicates from non-metallic ores, especially phosphate rock. They are used in amounts ranging from 0.2 lb. per ton of ore, either alone or with other promoters such as petroleum distillates, or pine oil or materials such as hydrocarbon oils, fatty acids or esters, in aqueous solutions or emulsions or in organic solvents such as alcohol. Results are given of tests on deslimed phosphate rock using pine oil with lauroyl diaminobutane acetate, N-lauryl ethylene diamine hydrobromide, myristoyl ethylene diamine hydrochloride, lauroyl ethylene diamine hydrochloride or N-lauryl N1-hydroxyethyl ethylene diamine hydrobromide. The treatment of rake classifier sands from cement works and of iron ores also is referred to.