Development, Testing and Demonstration of an Optimal Fine Coal Cleaning Circuit

摘要

The objective of this project was to improve the efficiency of the fine coal froth flotation circuit in commercial coal preparation plants. The plant selected for this project, Cyprus Emerald Coal Preparation Plant, cleans 1200-1400 tph of Pittsburgh seam raw coal and uses conventional flotation cells to clean the minus 100-mesh size fraction. The amount of coal in this size fraction is approximately 80 tph with an average ash content of 35%.rnThe project was carried out in two phases. In Phase I, four advanced flotation cells, i.e., a Jameson cell, an Outokumpu HG tank cell, an open column, and a packed column cell, were subjected to bench-scale testing and demonstration. In Phase Ⅱ, two of these flotation cells, the Jameson cell and the packed column, were subjected to in-plant proof-of-concept (POC) pilot plant testing both individually and in two-stage combination in order to ascertain whether a two-stage circuit results in lower levelized production costs. This paper focuses on the POC test results. Therefore, the bench-scale test work is summarized for only the Jameson and packed column cells.rnThe Phase I results indicated that the Jameson cell and packed column cell would be amenable to the single- and two-stage flotation approach. POC tests using these cells determined that single-stage coal matter recovery (CMR) of 85% was possible with a product ash content of 5.5-7%. Two-stage operation resulted in a coal recovery of 90% with a clean coal ash content of 6-7.5%. This compares favorably with the plant flotation circuit recovery of 80% at a clean coal ash of 11%.