Briquetting of Fine Coal Using a Sodium Chloride Binder. Final Report

摘要

A pilot scale test study has demonstrated the economic and technological feasibility of producing dense, weather-resistant briquettes from fine particulate bituminous coal. The binder, in the amount of 34/100 of 1% of the end product by weight, consisted of a sodium chloride dendritic crystalline matrix. The proclivity for liberation of pyritic sulfur and ash from fine coal particles, minus 10 Mesh x 0, has rekindled interest among producers and consumers of coal as to pre-combustion Deep Cleaning, in efforts to comply with clean air standards. Process technology as to coal beneficiation presently is producing fine sized particles. A major hurdle is handling the material after treatment. Besides being a definite safety hazard, it is extremely difficult to transport and impossible to stockpile resulting fines. Present general practice includes dewatering, if size permits, then thermal drying to some moisture level, say 10%. The dried fines are then blended with one or more produced fractions and shipped. This in itself is counter-productive as the difference in moisture content between these fines and that marketed can be as high as 8% or some 1000 Btus per pound. Reconstitution of this fine particulate seemed a reasonable solution to this situation and accordingly this study has been made. Briquettes have been produced which are equivalent to lump natural coal as to physical attributes. Generally, their heat value is greater as they contain less moisture and subjective burn tests for the product show a fouling index increase range from 10.5% for the low volatile seam to a high of 15.4% for the high volatile seam due to the sodium content of the additive. The scale-up cost for a 10 ton/hour operation including labor and capital servicing-payback is calculated to be $16.68 per ton. (ERA citation 07:003204)