Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. Third quarterly technical progress report, April 1, 1993--June 30, 1993.

摘要

The initial stages of pyrite oxidation are being studied to develop methods to control pyrite surface chemistry and foster pyrite rejection in coal flotation circuits. A major objective of this work is to study incipient oxidation, which is accomplished by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at various values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled. The oxidation and reduction products on pyrite following fracture are being studied by a combination of voltammetry, photocurrent, and impedance spectroscopy techniques. During this report period, major effort was devoted to characterizing the surfaces by impedance spectroscopy.