This Small Business Technology Transfer (STTR) Phase II project addresses unmet analysis needs of froth flotation, a separations process widely used in the mining industry to separate worthless gangue from desired mineral particles. Phase I work has demonstrated the preparation of sensor membranes that permit the measurement of collector chemicals used in flotation suspensions. These sensors have been shown to be ideally suited for these measurements since they are not affected by turbidity, have high selectivity for collectors, and require no off-stream sample handling. The project will take advantage of the highly selective and fouling-resistant fluorous perfluoropolymer membranes introduced by the academic partner Phil Buhlmann. The Phase II project will optimize the sensing membrane characteristics to improve ion conduction and robustness. It will also assess the factors that affect sensor lifetime and engineer several prototypes to test at mining operations.
The broader impacts of this research are significant as it will enable the mining industry to be more sustainable in its approach to mineral recovery. Specifically, the research aims to significantly reduce the amount of toxic chemical waste associated with froth flotation and its inevitable environmental impact. The method has the potential of making the U.S. copper industry more competitive by reducing wasted collector while simultaneously improving mining sustainability by eliminating an estimated 24 tons of unnecessary chemical discharges. In addition to these benefits, the multidisciplinary aspects of this project will train students in synthetic and analytical techniques, involving concepts from chemistry, materials science, and engineering.
Flotation is a separations process widely used in the mining industry to separateworthless gangue from desired mineral particles. It involves selective collector reagents that react with the desired mineral to accomplish the separation. Flotation cells are typically operated with an excess of reagents to avoid the loss of valuableminerals. This project developed selective chemical sensors for on-linemeasurements of xanthates, which is the most important collector reagent in the copper industry. Theproject took advantage of the highly selective and fouling-resistant fluorous perfluoropolymer membranes introduced by the academic partner Phil Buhlmann. A key goal of this of this research was to develop chemical sensor technology that would improve mining sustainability. A key area that is currently under great scrutiny bythe industry is the chemical reagent usage and environmental impact. The introduction of selective electrochemical sensors for xanthates provided the necessary measurement instrumentation to significantly reduce pollution in mining operations and reduce energy consumption. In addition to these benefits, the multidisciplinary aspects of this project trained students in synthetic and analytical techniques, involving concepts from chemistry, materials science, and engineering. A graduate student had the opportunity to mentor undergraduate students involved in this project through directed research studies and through the NSF-REU at the UMN.
