Review of the characteristics and graded utilisation of coal gasification slag

Abstract

The characteristics of the energy structure of rich coal, less oil and less gas, coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal, have brought opportunities for coal chemical industry. However, with the large-scale popularisation of coal gasification technology, the production and resulting storage of coal gasification slag continue to increase, which not only result in serious environmental pollution and a waste of terrestrial resources, but also seriously affect the sustainable development of coal chemical enterprises. Hence, the treatment of coal gasification slag is extremely important. In this paper, the production, composition, morphology, particle size structure and water holding characteristics of coal gasification slag are introduced, and the methods of carbon ash separation of gasification slag, both domestically and abroad, are summarised. In addition, the paper also summarises the research progress on gasification slag in building materials, ecological restoration, residual carbon utilisation and other high-value utilisation, and ultimately puts forward the idea of the comprehensive utilisation of gasification slag. For large-scale consumption to solve the environmental problems of enterprises and achieve high-value utilisation to increase the economic benefits of enterprises, it is urgent to zealously design a reasonable and comprehensive utilisation technologies with simple operational processes, strong adaptability and economic benefits.