Performance Evaluation Optimization of Coal Preparation Plants

摘要

Performance evaluation of a preparation plant, also referred to as a plant audit, evaluates plant performance under normal operating conditions and is aimed at improving yield by providing detailed information on actual process performance and interaction between different processes.rnThis paper describes components of the program, results, and impact on plant clean coal recovery. The four components of performance evaluation are: sampling plan and analysis, material balance flowsheet, calculation of performance parameters-density, size, and flotation separators-and overall plant optimization. Two software packages developed to streamline performance evaluation calculations and maximize mass yield are also described briefly.rnMost heavy medium cyclone circuits operated efficiently, at or near optimum. Heavy medium bath performance was impaired in some plants due to excessive ash content and misplaced fines in the feed. Water-only cyclone and flotation processes were influenced by changes in feed rate and misplacements during screening of fine particles. Improvements in the two processes would significantly improve the overall clean coal recovery. Steps to achieve improvements are briefly outlined. Results indicate that, in general, plant recovery could be increased between 1% and 7% by adjusting and fine-tuning the operating conditions and/or implementing some flowsheet changes. Overall, plant optimization may further increase recovery by 0.1% to 3%, depending on variations in coal washability of the feed to different processes.