LI Meng;CHEN Xueli;LI Fenghai;XU Jianliang;LIU Xia;

• 1:Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality
• 2:Ministry of Education
• 3:East China University of Science and Technology
• 4:School of Chemistry and Chemical Engineering

Abstract：

The reserve of high ash fusion temperature coal in China is huge, and the content of silicon and aluminum in the ash is high, while the content of basic oxide in some sludge is high. The co-gasification of sludge and high ash fusion temperature coal provides the possibility of regulating the ash melting characteristics of high ash fusion temperature coal. In this study, the effects of municipal sludge(CS) and pharmaceutical sludge(ZY) on the ash melting characteristics of Jiaozuo coal(JZ) with high ash fusion temperature were investigated. The results show that adding CS ash and ZY ash to JZ ash can reduce ash fusion temperature of JZ and adding ZY ash has a more significant effect on reducing the ash fusion temperature of JZ. When the CS and ZY ash ratio is 15% and 10%, respectively, the flow temperature of JZ-CS and JZ-ZY mixtures are reduced to below 1 380 ℃ to meet the slag discharge requirements of entrained flow gasifier CS ash has a high CaO content, and ZY ash has a high Fe_2O_3 content. With the addition of CS ash, the amount of anorthite formed by reaction of CaO in CS ash with Al_2O_3 and SiO_2 increases, and its co-melting with quartz results in the increase of liquid phase content and the decrease of ash melting temperature. Under a weak reducing atmosphere, the Fe~(3+) in JZ-ZY ash is reduced into Fe~(2+), and iron-bearing minerals such as hercynite increases. Hercynite with low melting point can melt at low temperature, and iron-bearing minerals easily form low melting point eutectic with other minerals, which decreases the ash fusion temperature(AFT) of JZ. When the proportion of sludge ash added is the same, compared with JZ-CS ash, JZ-ZY ash has a lower theoretical solid content, lower intensity and quantity of crystal phase diffraction peaks. When the temperature is 1 500 ℃, the mixed ash with 25% ZY ash reaches the full liquid state, while the mixed ash with 25% CS ash still contains some mullite. Mole ionic potential α is positive linearly correlated with the characteristic temperatures of both types of mixed ash. The decrease in α value of JZ-ZY ash is greater, so the melting temperature of JZ-ZY ash decreases more significantly.

Key Words： high ash fusion temperature coal;sludge;ash melting characteristic;flow temperature;regulation mechanism

Abstract:

Keywords:

Foundation: 上海市2020年度“科技创新行动计划”社会发展科技攻关资助项目(20dz1203300)

Authors: LI Meng;CHEN Xueli;LI Fenghai;XU Jianliang;LIU Xia;

DOI: 10.13226/j.issn.1006-6772.AC23061201

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