New concept for coal wettability evaluation and modulation. Technical progress report, January 1, 1995--March 31, 1995

This project is concerned with the new concept for coal surface wettability and floatability evaluation and modulation. The objective of the work is study the fundamental surface chemistry features about the evaluation of the surface wettability and floatability of coal and pyrite, and establish a new separation strategy which could contribute to advanced coal-cleaning for premium fuel application. During this quarter, the mini-flotation cell tests are conducted to study floatability of coal and pyrite. The three coals, coal pyrite and Colorado mineral pyrite samples are used in these tests. The kinetic floatability of the five samples have been tested without collector, with 3% and 6% NaCl solution. The test results have shown that there are good agreement between the experimental observation and the theoretical hypothesis about the new concept about the surface wettability and floatability of the coal and pyrite. The experimental results indicate that the coal floatability increase rapidly, but the floatability of coal pyrite and mineral pyrite are not change significantly with the addition of NaCl in flotation. It can be seen that the coal floatability increase as NaCl concentration increase. 14 figs., 5 tabs