On-Site Evaluation of a Fine Coal Cleaning Circuit Using a Stack Sizer and a Falcon Enhanced Gravity Concentrator

摘要

A single deck full-scale Stack Sizer in conjunction with a Falcon Concentrator having a feed handling capacity up to 5 tph was used to demonstrate a new fine coal cleaning circuit especially for high sulfur coal in this study. The experimental program was conducted to treat a slip stream from the feed to the raw coal cyclones operating in a coal preparation plant in the Midwestern US. High efficiency size separation achieved is described by an imperfection value of 0.21 and ultrafine bypass of 4.72% at a d50c of 77 micron. A reasonably low 1.74 specific gravity of separation was achieved by the Falcon Concentrator along with a probable error (Ep) value of 0.13 for cleaning nominally 1-mm × 75-micron coal. For a hypothetical fine coal cleaning circuit treating 100 tph of raw coal, the estimated total cost per ton of feed coal for the traditional fine coal cleaning circuit and the proposed new circuit are $4.93 and $5.89, respectively. However, the authors believe that the significant reduction in sulfur penalty due to better pyrite rejection achievable with the proposed circuit may offset the higher cost of cleaning high sulfur coal.