Multistream, multiproduct, pressure manipulation beneficiation

Abstract

An improved method and apparatus for froth flotation separation of the components of a slurry, having particular utility for the beneficiation of coal by the flotation separation of coal particles from impurities associated therewith, such as ash and sulfur. In this arrangement, a forward product stream is formed in which a mixture of the particulate matter slurry and the chemical reagents is sprayed through a nozzle at a first relatively low pressure onto the surface of water in a forward stream flotation tank to create a floating froth phase containing therein a first quantity of the particulate matter. The remainder of the particulate matter slurry separates from the froth phase by sinking in the water, and the froth phase is separated as a first product. The remainder of the particulate matter slurry is then directed to a scavenger product stream in which the separated slurry is sprayed through a second nozzle at a second higher pressure onto the surface of water in a second scavenger stream flotation tank to create a floating froth phase containing therein a second quantity of the particulate matter. The second froth phase is then separated as a second product. The amounts of the products recovered in the first and second product streams are substantially independently adjustable by controlling the first and second spraying pressures.