Environmental effects and resource potential evaluation of trace elements in coal and its by-products from power plant
The enrichment patterns of sensitive and key elements in coal and its by-products of power plants can provide a basis for controlling environmental pollution caused by coal combustion and utilizing solid waste resources.Taking the raw coal,fly ash,and bottom ash from a power plant in Xuzhou,Jiangsu for example,the environmental risks of sensitive elements and the resource potential of key elements were assessed based on the analysis of the enrichment characteristics of trace elements in coal and by-products.The results showed that the coal of the power plant was medium lead,low cadmium,low arsenic and very low mercury coal;Compared with the coal of the world,the element Cr was enriched,the key elements Tm and Se were deficient,the elements Li,Sc,Ga,La,Ce,Sm,Er,Yb,Y and other elements were slightly enriched,and the other elements were normal;Most trace elements were enriched in the coal-fired by-products,and the contents of Li,Sc,Ga,Zn and Pb were higher compared with the world ash,and the differentiation coefficient showed that the environmentally sensitive elements and key elements were more enriched in the fly ash(excluding Cr),and the similar differentiation coefficients and distribution patterns of rare earth elements indicated weak fractionation;The results of the Nemerow index method and the potential ecological risk index method showed that the environmental risks of sensitive elements in coal and by-products were low,and the environmental pollution risk of fly ash was higher than that of raw coal and bottom ash,the difference of environmental risks of sensitive elements in coal and by-products was affected by the enrichment characteristics and physiological toxicity of elements;The enrichment ratios of elements Li,Sc,Ga,Ge and Y relative to the base value were less than 0.5,and the recycling potential was small;The prospect coefficient of rare-earth elements and the proportion of critical rare-earth elements indicated that they have certain development and utilization potential,and it was considered that the selenium in coal-fired by-products had potential utilization value combined with the relationship between the selenium content in soil and in crops.
coal-fired by-productstrace elements in coalheavy metalsstrategic elementsenrichment
万方数据
维普
