A flotation column has been developed Incorporating the use of fine air bubbles (less than 100 microns) to remove ash-forming minerals from micronized coal. The microbubble generator used In this work has been characterized and found to yield a very narrow size distribution. Microbubble column flotation tests have been conducted to study a series of operating variables such as time, bubble size, feed rate, feed point, feed percent solids, column height, bubble number concentration, make-up water addition and countercurrent wash water addition. The results show that i) fine air bubbles are Inherently better suited for floating small particles; ii) both ash and recovery rates Increase with Increasing feed rate, distance of the feed point from the tailings port, feed percent solids and bubble number concentration; iii) taller columns result In Improved recovery and ash rejection; and iv) the countercurrent wash water addition minimizes the entrainment of mineral matter to the froth product. Proper control of these parameters makes It possible to produce super clean coal (< 2% ash). / M.S.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/90973 |
| Date | January 1987 |
| Creators | Keyser, Paul Martin |
| Contributors | Mining and Minerals Engineering |
| Publisher | Virginia Polytechnic Institute and State University |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | xiv, 167 leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 16679242 |
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