Feasibility of a Phosphate Recovery Circuit for Existing Waste Streams

72325B03-I Phosphate beneficiation plants currently pump hundreds of thousands of gallons of fine refuse into waste impoundments every minute. This refuse contains not only fine phosphate, considered unrecoverable by current industrial practice, but also coarse phosphate that has been misplaced due to sizing inefficiencies. Unfortunately, this lost phosphate is a large portion of the total valuable mineral extracted during the mining process. Its rejection represents poor separation and energy efficiency, and its recovery would reduce production costs and lessen the amount of waste sent to impoundments. This project will develop a mineral processing circuit for the economical recovery of phosphates that are currently being discarded. This process includes column froth flotation preceded by a combination of advanced hydroclassification techniques. In Phase I, existing data from producers, as well as data collected directly from waste streams, will be used to determine the available phosphate values present in the typical refuse stream. A laboratory analysis will be used to predict phosphate recovery for a full-scale circuit. All data, both previously collected and newly produced, will be evaluated to determine the economic and technical feasibility of the proposed circuit. Commercial Applications and Other Benefits as described by awardee: Because no phosphate beneficiation plant incorporates a recovery circuit for the treatment of fine refuse, commercial applications should include the fabrication and installation of the required equipment for every available plant. This circuitry may also be applied to dredging processes that may be used for recovering phosphate directly from refuse impoundments.