Methods for Improving Slurry Ability of Yangchangwan Bituminous Coal

Abstract

Yangchangwan (YCW) bituminous of Ningxia is a weakly reductive coal, which was characterized with low ash content, low sulfur content, low H/C and ash fusion, but high moisture, oxygen, inertinite and alkaline earth metal contents, also difficult to make slurry. Influence of dispersant kind and dosage on YCW CWS rheological behavior was studied using 8 dispersants. Examination was conducted in the lab. The results show that the dispersant and its dosage not only influence the apparent viscosity but also the rheological behavior of CWS. Methyl naphthalene acid salt formaldehyde condensation(MF) is the best dispersant for YCW bituminous coal and the optimal dosage is 1%. CWS were also prepared using compounded dispersants of sodium lignosulphonate and Methyl naphthalene acid salt of formaldehyde condensation and in order to investigate the slurry ability of CWS with compounded dispersants. The results show that compounded dispersants have a greater impact on the liquidity and stability of CWS, the optimal ratio of two dispersant is 3:7. Slurry technologies of blended coals were also studied in this paper, YCW bituminous coal with lower slurry ability , lower static s stability and poor theological behavior and Dafeng(DF) anthracite coal with good properties of CWS and the better theological behavior. The effect of the ratios of two coals on the static stability and viscidity of CWS was studied. The results show that CWS is better static stability ability and viscidity when the chemical additive quantity is at 1 parts per hundred and the ratio of two coals is 3:7.The effects of coal blending on the features of coal-water slurry are nonadditivity. It can effectively improve the concentration of coal water slurry, for coal which has difficulty in preparing coal-water slurry.