Interparticle interaction between coal grains through an alkane

The results of the destruction time of the sediment column structure of coa l grains in alkane from hexane to hexadecane are reported. The destruction time was measured in a simple device constructed in our laboratory. The cha nges in the destruction time were explained by calculations of the attachme nt and detachment forces which result from interfacial and gravitational in teractions, respectively. In equilibrium conditions, the attachment force i s equal to the detachment force, and coal grains did not detach from one an other. The diameter of such grains, called the critical diameter, was deter mined from the linear relationship between the reciprocal of the destructio n time and the average diameters of the coal grains. It was found that the critical diameter of the coal grains did not depend on the length of the hy drocarbon chains. The increase in the destruction time with the length of t he hydrocarbon chains is due to the decrease of the detachment forces and t he increase of the perimeter of the contact plane between two coal grains i n thr alkane, which was shown by calculation of the attachment force per co al grain. It was also found that the detachment of coal grains from one ano ther occurred by disruption of the alkane film present between the coal gra ins.