Ideal coal water slurry (CWS) with maximum coal loading should be relatively stable at static stability and good rheological behavior. Additives have usually been used to improve the slurryability and rheological behavior as well as static stability of CWS to meet requirement of its transportation, storage and combustion in industrial application. The selection of high efficient additives is one of the key steps for preparation of CWS. Therefore, the investigation of the relationships between the properties of CWS and molecular structure of additives plays an important role in selecting high efficient additives. In this paper, 7 additives with different structural characteristics and 8 coals are selected to evaluate the correlation between the structural characteristics of additives and the properties of CWS. The results indicate that introducing methyl substitute into the monomer of polynuclear aromatic sulphonate promotes the rheological behavior and the static stability of CWS, but at the same time it is unfavorable for the slurryability of CWS. The presence of benzyl substitute improves the slurryability of CWS prepared with coals of low content of Oad, but it is unfavorable for improving the static stability of CWS. CWS with high coal loading could be prepared by using both low rank coals with a lot of polar oxygen groups and humate additive with high degree of sulphonation. It is also found that additives of humate and lignosulfonate with high degree of sulphonation increase the static stability of CWS prepared by coals with high content of Vdaf.
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