基于多重散射光理论的石油焦/褐煤共成浆稳定性的研究
Static stability of petcoke / lignite mixture slurry based on multiple light scattering theory
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摘要: 利用基于多重散射光技术的Turbiscan LAB稳定性分析仪,从宏观相分离程度和介观颗粒粒度的角度研究了石油焦/褐煤配比对混合浆体稳定性的影响。结果表明:焦煤比>7∶3时,浆体在静置0~7 d内出现明显的颗粒团聚并迁移的现象,且焦煤比越大,顶部分层厚度越大,颗粒向下迁移速率越大。焦煤比6∶4时,浆体在0~90 min内顶部较大颗粒的沉降造成中部平均粒径增大;1~7 d内中部大颗粒团聚并逐渐向下迁移,中部平均粒径逐渐减小。焦煤比≤6∶4时,浆体平均粒径在0~90 min内保持稳定不变;1~7 d内中部颗粒团聚但没有迁移,中部平均粒径逐渐增大。在静置7 d中,不同焦煤比浆体稳定性由好到坏的焦煤比顺序为:0∶10和5∶5最好,其次依次为6∶4,7∶3,8∶2,9∶1,10∶0。因此从宏观和介观角度分析,焦煤比>7∶3的混合浆体由于颗粒聚结和迁移导致体系析水、分层及不稳定;焦煤比≤7∶3的混合浆体颗粒在静置过程中团聚但不迁移,体系稳定性较好。Abstract: This paper investigated the effect of different mass ratios of petcoke / lignite on the static stability of mixture slurries from the macro-scale (phase separation) and mesoscopic scale (particle size) by using Turbiscan LAB stabil- ity analyzer based on multiple light scattering technology. The results showed that when the mass ratio was greater than 7 ∶ 3,the particles in the slurry aggregated and migrated,and the greater the mass ratio,the greater the top layer thick- ness and particle migration rate in 0 -7 d. When the mass ratio was smaller than 7 ∶ 3,the particles aggregated but didn’t settle which caused the increase in average particle size and no visible clear layer on the top of the slurry in 1-7 d. Besides,when the petcoke / lignite mass ratio was larger than 6 ∶ 4,the large particles on the top settled and thus increased the average particle size of the middle part between 0 -90 min,after that the particles in the middle part gradually aggregated and migrated to the bottom of the slurry in 1-7 d. When the mass ratio was smaller than 6 ∶ 4,the average particle size of the middle part remained stable between 0 -90 min,after that the particles in the middle part aggregated and increased the average particle size of the middle part. The order of static stability of slurries pre- pared by different petcoke / lignite mass ratios is that 0 ∶ 10 and 5 ∶ 5 are the best,the other order is 6 ∶ 4,7 ∶ 3,8 ∶ 2,9 ∶ 1,10 ∶ 0. Therefore,from the macro-scale and mesoscopic scale analyses,the mixture slurries with mass ratios greater than 7 ∶ 3 bled moisture,segregated and were unstable because of the coalescence and migration of particles. The mixture slurries with mass ratios equal or smaller than 7 ∶ 3 were stable because of the coalescence and no migra- tion of particles.