Abstract: Inorganic heavy-liquid sodium polytungstate, with the characteristics of high density, nontoxic, easily prepared and cyclic utilization, have been widely applied in geology, soil science, and marine biology. It is used for separating the mine and rock in geology, providing a new way for the separation of micro-fine simple mineral. For soil science, it is applied to separate the soil aggregation particles, organic matter, and humic acids. It is used for separating the microorganism and organic matter in sediments in marine biology. The sodium polytungstate density separation operation is simple and stable, and most inportantly the physic-chemical property of matter will not change.

Key words: Sodium polytungstate, Density separation, Geology, Soil science, Marine biology