不同降解方式对淀粉基水煤浆分散剂性能的影响

Effects of different degradation methods on dispersion properties of starch coal-water slurry dispersion

分别采用氧化法(H_2O_2为氧化剂)、酸解法(HCl)两种不同的方式制备降解淀粉,在相同的实验条件下,以丙烯酸(AA)、苯乙烯磺酸钠(SSS)为单体,H_2O_2-Fe^(2+)为引发剂,通过自由基聚合反应制备3种淀粉基水煤浆分散剂。通过红外光谱(FTIR)、核磁共振氢谱(1H NMR)、凝胶渗透色谱(GPC)对产物的分子结构、相对分子质量及分布进行了表征和分析。将3种分散剂应用于彬长煤制浆,考察对比了浆体的表观黏度、分散剂最佳添量、最大制浆浓度、流变性、Zeta电位、吸附特性及静态稳定性等。结果表明,经氧化降解制备的淀粉基水煤浆分散剂在最佳添加量0.4%(质量分数)时,水煤浆最大制浆浓度可达到67%,表观黏度为906m Pa·s,煤粒表面的Zeta电位由–12.1m V变化到–47.3m V,相较于由玉米淀粉及酸降解淀粉制备的水煤浆分散剂对彬长煤具有更好的降黏、分散、稳定作用。

Degraded starch was obtained by two different degradation methods of oxidative degradation（take H_2O_2 as oxidant） and acid degradation（HCl）. Under the same experimental conditions,three types of starch coal-water slurry dispersants were prepared by radical polymerization with acrylic acid（AA） and sodium p-styrene sulfonate（SSS） as monomers,and H_2O_2-Fe2＋ as initiation. Their structures,molecular weights and distributions were characterized and analyzed by FTIR,1H-NMR and GPC. The three types of dispersants were applied to Binchang coal,and the apparent viscosity,the optimum dosage,the maximum slurry concentration,rheological behavior,Zeta potential,adsorption,static stability of the slurries were investigated and contrasted. The results showed that when the dosage of dispersant was 0.4%,the highest of concentration of CWS can reach 67%,and the apparent viscosity was 906 m Pa·s,and the Zeta potential changed from –12.1 to –47.3m V. The starch coal-water slurry dispersant prepared by oxidative degradation,show better performance on viscosity reduction,dispersal,stabilization for Bingchang coal than those prepared by acidified starch or corn starch.