MINERAL-COMPOSITION OF ATMOSPHERIC PARTICULATES AROUND A LARGE COAL-FIRED POWER-STATION

The present work is a mineralogical study of atmospheric particulates around a large coal-fired power station in NE Spain. After a mineralog ical study of the fly ash sampled in the electrostatic precipitators o f the power station, several chemical and mineralogical patterns of th e fly ash were employed as tracers of the power station emissions. At the same time, the study focused on the downwind evolution of secondar y particulate matter, especially particulate sulphate. The studies on the mineralogy of air borne dust allowed us to distinguish between nat ural and anthropogenic particles. The major mineral phases identified in the samples studied were: gypsum, calcite, clay minerals (kaolinite , clinochlore and illite), quartz, talc and hematite. In addition to t hese mineral phases which are frequently present in the atmospheric pa rticulate matter of the studied area, other mineral phases, such as fe ldspars, mullite, and copper sulphates, were detected in minor proport ions. The results show that some mineralogical and morphological chara cteristics of the atmospheric particulate matter may be used as tracer s of the influence of coal-fired power plant emissions. These characte ristics include spherical morphologies, aluminosilicate glass, mullite , hematite and sulphate-fly ash associations. The possible buffering e ffect of atmospheric Ca-bearing minerals to neutralize the sulphate de position is investigated. Copyright (C) 1996 Elsevier Science Ltd