Coal Fire Sublimates: Are We Missing Something?

Abstract

Uncontrolled coal fires present a nearly unparalleled environmental and human health disaster. These fires can cause the destruction of the ecosystem, ignite forest fires, become a source of windblown dust and siltation of streams, and pollute surface water, ground water, and crops. They can cause significant disruption of families and communities resulting from physical hazards of collapse or explosion, excessive heat, visual blight and loss of potentially valuable acreage, deterioration of cultural infrastructure, personal and public property, and loss of a valuable energy resource. The emission of CO2 and other greenhouse gases presents a significant health hazard due to respiration of dust and aerosols, and exposure to acidic gases, potentially toxic trace elements, and organic compounds. Numerous studies have described many dozens of phases that have condensed from the effluents of these fires. However, many of these studies may have overlooked the nano- and ultra-fine particles that exist beside, in, and under the brightly colored, often spectacular crystalline macro phases. Using a scanning electron microscope with an energy dispersive X-ray detector we examined a small (30 mm × 10 mm) piece of condensate from an uncontrolled coal fire in the Jharia region of India and found more than 30 different phases in this one small piece. The phases included ammonium, copper, iron, lead, bismuth chlorides; bismuth, lead, and ammonium silici-fluorides; ammonium and lead iodates; iron, barium, lead, copper, and zinc sulfides; iron and silicon oxides; and others. Broken fragments revealed multiple generations of phases. Though not strictly nanoparticles (smaller than 0.1 μm), many of these particles are in the micrometer to sub-micron range and it is likely that there are phases present in the nanoparticle size range. Certainly, particulates in the nanoparticle and ultra-fine particle range are being released from the uncontrolled coal fires and may be impacting the environment and the health of the mine workers and nearby residents, an issue that should be investigated.

Trace Elements in Pernik Sub-Bituminous Coals and Their Combustion Products Derived from the Republika Thermal Power Station, Bulgaria

“…On the other hand, the constant heating of Pernik coals by active fires at depth, caused by their spontaneous combustion, is probably also a factor in the type of char particles formed [22,28,44]. During this process, volatile components are released [14], as well as a change in the vitrinite structure depending on the temperature and lack of oxygen [45,46].…”

“…In the processes of coal beneficiation and coal combustion in thermoelectric power stations (TPSs), several major waste products are generated, namely coal slurry, associated host rocks, bottom ash, and fly ash. It is well known that the detailed knowledge about the mineralogy and inorganic chemistry of these products has important fundamental, technological [1][2][3][4][5][6][7][8][9], and ecological [10][11][12][13][14][15] significance. Therefore, valuable information on the inorganic composition of coals and their combustion products has been summarized in several monographs [16][17][18][19].…”

Nanomineral and Their Importance on the Earth and Human Health: A Real Impact

“…This makes it significantly easier for REEs to be extracted. In addition, owing to their proximity to roads and rail transport in the regions under study [2], the opportunity exists for such resources (BFCTs) to be utilized as a secondary market as opposed to simply being discarded, which has been the case in the past [3]. Particulates in the nanoparticle and ultra-fine particle range are being released from uncontrolled coal fires and may be impacting the environment and the health of the mine workers and nearby residents, an issue that should be investigated [3].…”