CHALLENGES AND OPPORTUNITIES OF UTILIZATION OF ASH AND SLAG WASTE OF TPP (THERMAL POWER PLANT). PART 1

Abstract

 The further development of the Russian coal industry, especially in the regions of Siberia and the Far East, in line with the  Energy Strategy, predetermines the need to address the problem of  utilization of ash and slag wastes in newly implemented projects.  The total amount of ash and slag in the ash dumps in Russia is more  than 1.5  billion tons, and the area occupied by fly ash and slag wastes  (FASW) is more than 220 km2. At the same time, the degree of FASW  use does not exceed 10  %. It is shown that the main solutions for the  recycling of the industrial solid waste generated by thermal power  plants are their use in the production of building materials, road construction, or the complex processing of FASW with the extraction  of metals and the production of building mate rials either. Some fly  ash can be used in agriculture. The physicochemical properties of  fly ash and slag wastes and, accordingly, the directions of their use,  as well as the choice of technology, are determined by the mineral  part of the fossil coals and the way they are burned. To use fly ash in  the construction industry, it is necessary to transfer the ash removal  system to the dry method, accompanied, on the one hand, by a large  volume of capital investments in equipment and facilities for storage,  classification, crushing and grinding, the transfer of new physical and  chemical properties to fly ash and slag waste, and on the other side,  an increase in organizational and transport barriers. Examples of proposed technologies for utilization of ash and slag wastes in the form of metal recovery and production of building materials are given. To  obtain iron-containing concentrates, one-stage magnetic separation  is used, but the quality of the concentrate does not meet modern requirements. The most technologically effective for the extraction of  metals from ash and slag wastes are technologies based on flotation  methods. At the same time, it follows from the provided data that  their application can be limited to economic, organizational factors  and the emergence of new environmental risks. The conclusion is  made on the possibility of using the above technologies for existing  coal-fired power plants only with state support.