New and improved collector compositions for use in froth flotation processes for the beneficiation of mineral values from base metal sulfide ores are disclosed. The collector compositions comprise at least one hydrocarboxycarbonyl thiourea compound selected from compounds of the formula: ##STR1## wherein R.sup.1 is hydrogen or R.sup.2 ; R.sup.2 is selected from saturated and unsaturated hydrocarbyl radicals, hydrocarboxy radicals and aromatic radicals; and R.sup.3 is selected from saturated and unsaturated hydrocarbyl radicals, alkyl polyether radicals and aromatic radicals, said R.sup.2 and R.sup.3 radicals, optionally, and independently, being substituted by polar groups selected from halogen, nitrile and nitro groups. The use of the hydrocarboxycarbonyl thiourea collectors provides excellent metallurgical recoveries of sulfide mineral values in froth flotation processes conducted over a very broad range of pH including acid, neutral and mildly alkaline pH.