Zeta potential of different lithotypes in Shenfu coal

The zeta potential of different lithotypes of two coals with high content of inertinite in Shenfu Coalfield has been studied. Moreover, the effects of pH value and the addition of surfactants and inorganic salts on zeta potential have also been discussed. It has been concluded that the zero potential point (ZPP) of vitrain is between about 3.30 and 3.40 of pH value, but that of fusain is between 2.00 and 2.10 of pH value. Furthermore, it has been found that vitrain could reach its ZPP once a small amount of cationic surfactants and some inorganic salts were added to pulps. However, only when a large amount of cationic surfactants and some inorganic salts were added to pulps, could fusain reach its ZPP. The conclusions are useful in the efficient separation and preparation of single petrographic constituent.