Current Status and Prospect of Fly Ash Utilization in China

： About 500 million tons (Mt) fly ash produces from coal-fired power stations every year in China, which causes severe economic and environmental problems. In this paper, current status and prospect of fly ash utilization in China was introduced in detail. China is a huge country which has many different geographical environments and various level of economic development. So, the level and method of different area are various. In general, fly ash is mainly used as an additive in concrete and cement in the south of China and thereof little fly ash is piled up, while in the north of China, it can be used as the alumina production material besides the utilization ways mentioned above. As a prospect, high-valued utilization of fly ash is being undertaken, such as producing inorganic fiber or geopolymer. 1.Introduction Fly ash is an ultrafine solid residue generated from coal fired power plants. It is the largest quantity of industrial solid waste in China. At present, the output of fly ash in China is estimated to be 500 Mt every year 1. Domestic fly ash discharge is directly related to China's fast development of national economy and its energy structure of primary energy consumption. During the past several years, the Chinese economy remains red-hot with GDP growth rates exceeding 8%. On the other hand, Coal accounts for 68.8% of China's primary energy consumption, which is more than two times of the world average. In the near future, this energy structure cannot change since China is short of nature gas or crude oil 2. Furthermore, China's coal washing rate is very low currently – only 51% in 2010 – compared to rates of 94.9% in England, 88.7% in France, and 98.2% in Japan, although it is well known that coal washing can greatly reduce the ash production 3. The quantity of fly ash generated in China is too huge to be completely consumed. It has to be collected in the ash ponds or in the open lands. Some of this ultrafine matter inevitably enters into atmosphere with wind. Usually fly ash can deposit in the nearby 5-10 km environments of the coal fired power plants. Fly ash contains several main elements including