30 Environmental & Socio-economic Studies © 2015 Copyright by University of Silesia DOI: 10.1515/environ-2015-0071 Environ. Socio.-econ. Stud., 2015, 3, 4: 30-38 ________________________________________________________________________________________________ Trace elements and mineral composition of waste produced in the process of combustion of solid fuels in individual household furnaces in the Upper Silesian Industrial Region (Poland) Danuta Smołka-Danielowska Department of Geochemistry, Mineralogy and Petrography, Faculty of Earth Sciences, University of Silesia, Będzińska Str. 60, 41- 200 Sosnowiec, Poland E–mail address: danuta.smolka-danielowska@us.edu.pl _______________________________________________________________________________________________________________________________________________ ABSTRACT This study presents preliminary research results, with regard to the concentration of chosen trace elements (Mn, Cr, Tl, Ni, Cu, Zn, As, Cd, Ba, Pb) in waste, which was produced in the process of combustion of solid fuels (hard coal and flotation concentrate of bituminous coal) in individual household furnaces in Poland (in the Upper Silesian Industrial Region). 27 samples of ash, 4 samples of hard coal and 2 samples of flotation concentrate of bituminous coal were prepared for the research. Methods such as: ICP-MS, X-ray diffraction by means of the powder method and scanning electron microscopy were used during the research. In the ash samples obtained from the combustion of hard coal, the highest average concentrations were: Mn (1477.7 ppm), Ba (1336.4 ppm) and Zn (599.7 ppm). In the samples obtained from the combustion of flotation concentrate of bituminous coal, the highest average concentrations was stated for: Zn (762.4 ppm), Mn (668.5 ppm), Pb (552.1 ppm) and Ba (211.7 ppm). Crystalline components were determined by used the X-ray diffraction method and the samples of ash obtained from the combustion of hard coal contained: anhydrite, gypsum, hematite, magnetite, quartz, calcite, mullite, periclase, kaolinite, dolomite, pyrite, sphalerite, galena and feldspars (albite–anorthite). The samples of ash obtained from the combustion of flotation concentrate of bituminous coal contain: pyrite, quartz, potassium feldspar, muscovite and kaolinite. The scanning electron microscope analysis enabled the identification of the chemical composition of single ash grains and determined their morphology (aluminosilicate forms, substance PbS and ZnS, oxides of Ni, Cu and Mn, monazite, xenotime). KEY WORDS: ash, coal, chemical composition, mineral phases ________________________________________________________________________________________________________________________________________________ 1. Introduction In the Polish power industry about 38 million tons of hard coal are burnt every year. The consumption of hard coal and hard coal silt for heating individual homes amounts to about 10 million tons per year (GUS, 2015). In individual household furnaces people in Poland very often use fuels, which are sulphated and poor in quality. Usually about 70% of waste in the form of ash and slag is thrown away in municipal waste dumps, and the is expelled with combustion gases through the chimney (GRODZIŃSKA-JURCZAK, 2001; DEN BOER ET AL., 2010). Domestic furnaces are characterized by low combustion temperatures (assessed to be around 270°C). Old solid fuel boilers, characterized by low thermal efficiency (45-70%) are still used very often. In household furnaces flame coal and bituminous coal are fuels, which are used commonly. Flame coal can be used in all kinds of grate furnaces. It has high fly ash content (35-44%) and in praxis it does not agglomerate. Flotation concentrate bituminous coal maintains its hard coal properties (eg. chemical and mineral composition, carbon content, calorific value). It is a mixture of tiny coal grains and gangue, which along with it is carried away to special decanters during the process of mechanically working hard coal. In individual households, chamber furnaces with a flat grate are usually used, because they are supplied manually and easily maintenaed. The respective phases of combustion (heating,