The Purification of Coal Tar by the Addition of Quinoline and Zn(OH)2

The coal tar was purified by the addition of quinoline and Zn(OH)2, in order to decrease the content of carbon and inorganic oxide particles. The effect on the viscosity and ash content of the coal tar were investigated by altering temperature, time, and the amount of quinolone and Zn(OH)2 . When the volume ratio between quinolone and coal tar was 20:1 and the static time was 24 h. The viscosity of three layers decreased with rising temperature. When the static temperature and time was 45 °C and 24 h, respectively. The viscosity of three layers decreased with the arising amount of quinoline. And when the volume ratio between quinolone and coal tar was 20:1 and the temperature was 45 °C. The viscosity of three layers decreased first and then increased with the prolonging of static time. And when the static time of coal tar was 24 h, the viscosity of coal tar is the lowest. Because of the lower viscosity of coal tar, decreasing the content of carbon and ash particles in upper and middle layer, the ash content decreased from 0.168% to 0.092%. The addition of Zn(OH)2 can lead ash content in middle layer decrease to 0.058%. Zn2SiO4 and ZnAl2O4 may be produced due to the reaction between Zn (OH) 2 and SiO2 or Al2O3, which can settle down easily. The results show that the content of carbon and inorganic oxide particles in upper-middle-class (the middle 4/5 of the whole volume) decreased with the addition of quinolone and Zn(OH)2 . When the volume ratio between quinolone and coal tar was 50:2, quality ratio between coal tar and Zn(OH)2 was 20000:1, the mixture were heated up to 45 °C at atmospheric pressure and keeping this constant temperature for 24 h, the ash content in upper-middle-class can decreased to 0.058%.

Ping Zhou, Qian-lin Chen, Xian-quan Ao, Yan Xie and Chao Kang