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Show 3.0 TASK 2: PRELIMINARY CONCEPTUAL DESIGN OF 2G-tIh SEMIWORKS PLANT A preliminary conceptual engineering design of a 20-t/h semiworks plant for selective agglomeration was carried out in Task 2. This design represents the first stage in the detailed engineering development of this advanced physical fine coal deaning technology. All viable process options were examined, uncertainties were identified, and a preliminary flowsheet was developed based on the best information available at the time. A comprehensive literature search was conducted, data from other ongoing projects were reviewed, and agglomeration experts were consulted to formulate the initial conceptual design. The design criteria required that the plant be able to receive feed coal from conventional haulage dump trucks, maintain a 10-day coal supply, and clean 20 tjh of coal continuously using a selective agglomeration process. Other criteria Included sufficient flexibility and capacity to process all three of the test coals at a plant availability rate of 90%. The clean coal product was to be suitable for utility combustion, meeting the following specifications: o <6% ash o Maximum Btu recovery and pyrite rejection attainable at an economically feasible topsize In addition, the plant must produce a manageable refuse for disposal while complying with health, safety, environmental, and disposal regulations with regard to all product and effluent streams. The plant must be a complete, stand-alone facility, including a coal receiving and crushing area, a dedicated electrical substation, clean coal storage facility, and water clarification system. 4.0 TASK 3: DETERMINATION OF PROCESS UNCERTAINTIES The objective of Task 3 was to categorize and prioritize process uncertainties that must be resolved to ensure a successful plant design. A total of 107 uncertainties were identified from the preliminary engineering conceptual design of the 20-tjh semiworks plant. Two major categories of uncertainties were identified: process related and equipment related. These were subdivided into uncertainties that can be resolved through engineering analysis/evaluation and those that require experimentation/testing. A number of approaches were identified for resolving the uncertainties: literature survey, engineering analysis, bench-scale batch tests, small-scale continuous tests, test rigs, vendor tests, and proof-of-concept testing. A ranking system was developed in order to weight the uncertainties for prioritization. The primary ranking criteria were the relevance to the following project objectives: process performance (high Btu recovery and pyrite rejection), low product ash, acceptable product handling characteristics, required design data, and useful test procedures for evaluating other non-project coals. The secondary ranking criteria were: the resources (effort) required to resolve the uncertainty, and the impact of the uncertainty on the economics of the process. 5.0 TASK 4: TEST PLAN FORMULATION AND COAL PROCUREMENT The primary objective of Task 4 was to formulate a plan for the development of the selective agglomeration process which addressed all critical uncertainties Identtfled In Tasks 2 and 3 such that these deficiencies would be resolved by the completion of Phase I of this project. The plan consists of five separate sections which address coal procurement, coal characterization, uncertainties which can be resolved by engineering analysis, bench and pilot-scale tests, and component development tests. 2 |
