Bench-scale testing of the Multi-Gravity Separator in combination with Microcel. Fifth quarterly report, October 1, 1993--December 31, 1993

摘要

During the quarter ending December, 31, 1993, the independent, combined and long duration testing were completed for both the Pittsburgh No. 8 coal and the Illinois No. 6 coal. Overall, the project is on schedule and the bulk of the critical work, from a timing perspective, is complete. Table 1 summarizes the status of major project tasks as of December 31, 1993. Preliminary results provide strong evidence that combining the Microcel flotation column with the Multi-Gravity Separator has a synergistic effect. Overall ash and pyritic sulfur rejections of 75 %, at a 90 % combustible recovery, were consistently achieved on the Pittsburgh No.8 seam coal. On the Illinois No. 6 coal, pyritic sulfur rejections over 75 % and combustible recoveries of over 85 % were achieved. These results are discussed in this report. Although further analysis is taking place, it is very evident from the results presented herein that a well-designed and -operated flotation column performs well for ash rejection but not as well for pyrite rejection. It is equally evident that a good fine gravity separator can reject pyrite from coal but perform more poorly for ash rejection. The concept of combining the best of both units into one circuit has therefore been successfully tested in this project.