Preparation Of N-SAF Dispersant And The Application In Shenfu Coal

Coal Water Slurry(CWS)was regarded as a type of clean fuel. In order to make a slurrywith good fluidity, low viscosity and good stability, a certain dispersant should be added in thepreparation of CWS. Currently, anionic dispersants were used most widely. This paper aimedto prepare a suitable new anionic dispersant for Shenfu coal and studied the processconditions and performance of CWS.In this paper, a modified dispersant of CWS, namely N-SAF, was synthesized by acopolymerization of sulfanilic acid, formaldehyde and acetone copolymer. The structure ofthe dispersant was characterized by IR spectrum, relative molecular weight and the curing rate.The results showed that the molecular structure of the synthesized products were consistentedwith the target products. Optimal conditions of synthesis were determined by single factor andorthogonal experiments. When the mol proportion were sodium sulfanilate: sodium sulfite:acetone: formaldehyde=2:6:25:50, the sulfonated temperature was55℃, sulfonated timewas50min, condensation temperature was75℃, condensation time was2.5h, theperformance of synthetic dispersant was the best.A series of Shenfu CWS was formulated by N-SAF. The viscosity of different CWS hasbeen measured to determine the optimal dosage. According to the national standard, theoptimal conditions had been measured, such as calorific value, ash, sulfur and so on. Theresults showed that when the quality of pulverized coal was60g, the dispersant0.5g,(M分散剂M=0.83%) and the stabilizer0.1g, the viscosity of the obtained CWS was the lowest,干煤粉i.e.668mPa s. At the same time, the drainage rate was less than10%, the slurry had goodstability, and the maximum slurry concentration was63%. N-SAF dispersant was preparedwith a commercially available dispersing agent, the advantage of N-SAF was smaller amount, pulp concentration increased, low viscosity and good stability. By applying the N-SAF to theJincheng Coal and Hancheng coal, the dispersion in the CWS was found to be better.The sulfur content and nitrogen content had been measured in the CWS with the N-SAF.The results showed that the sulfur content and nitrogen content were increased by only0.01%and0.02%of CWS, compared with the raw coal. It indicated that the N-SAF dispersant hadless pollution to the environment.The mechanism of slurry dispersant of CWS is mainly can be effectively adsorbed on thesurface of coal particles, which can improve the hydrophilicity of coal, the formation of sterichindrance of electric double layersurface and in the coal particles, that made the coalparticle disperse.