Characteristic analysis and utilization of coal gasification fine slag based on particle size classification

A large amount of gasification fine slag with high carbon content is produced in the process of coal gasification.At present,it is mainly treated by landfill,which not only occupies a lot of land,pollutes soil and water,but also causes energy waste.How to efficiently and environmentally utilize gasification fine slag as a resource is the hot spot of current research.The separation of residual carbon and ash in gasification fine slag is the key to realize its high value, reduction and harmless utilization.The analysis of particle size characteristics of gasification fine slag shows that the ash content of each particle size increases with the decrease of particle size,and the separation and enrichment of carbon and ash can be realized by screening and classification process.The results show that the fixed carbon content of Yu- lin coal gasification fine slag decreases with the decrease of particle size.There are more Si()2 ,A1203 ,Fe2()3 and CaO in each particle size.The micro morphology is mainly composed of porous matrix, irregular small particles, flocculent particles and spherical particles.The results show that the pore structure of coal gasification fine slag is developed, the specific surface area is rich,and the products with particle size >75 [xm can be directly used as high-quality adsorption materials.Compared with the gasification fuel coal,the combustion character istic temperature of each particle size of coal gasification fine slag is significantly increased, and the ignition characteristic temperature is higher than that of anthracite except for <45 jxm particles.Due to the existence of rich porosity in gasification slag, the contact area be-tween particles and oxygen is increased, so that the peak combustion temperature of combustion is lower than that of anthracite and the burnout temperature is significantly lower than that of anthracite in middle and later stage of combustion.