Abstract: Coal is separated in a gravity separator using a fluorinated hydrocarbon parting liquid. The cleaned coal is burned and the ash mixed with recovered parting liquid and returned to the gravity separator. Additives may be dispersed in the parting liquid to alter the physical and/or chemical characteristics of the products. The additive may be a dustproofing or a waterproofing agent.

Abstract: Methods of and apparatus for cleaning coal in which fluorochlorocarbons are used as parting liquids. Various novel techniques, components, and combinations thereof are employed to maximize efficiency; to minimize costs and adverse environmental impacts; to make it possible to recover coal of a character which has heretofore been economically unrecoverable; to produce a superior product; and to reach other worthwhile goals.

Abstract: A sink-float method and apparatus for testing and separating a mineral such as coal in mineral products containing inert matter which employs a novel trapezoidally shaped testing tank, a mixture of perchloroethylene as a parting liquid and white gasoline as a dispersant and surfactant, and an implement in the form of a long stirring rod angulated at its end. The tank is provided with bars at the bottom to limit the movement of the implement. The invention provides a quick and precise test for specific gravity of raw crushed coal and its impurities.

Abstract: A method and apparatus for separating objects having a density greater than a selected density value from objects having a density less than said selected density value.

Abstract: The present invention is directed to a method for separating mature okra seed into its essential basic components of oil, germ, kernel material and hull. The separation is obtained by cracking the seed in, or immersing previously cracked seed in a liquid medium having a specific gravity of 1.3 plus or minus 0.2 at 60.degree. F. The liquid medium may be an aqueous solution adjusted with sodium chloride, sugar, or other water soluble organic material. However, in order to extract the oil, a solvent such as 1,1,1,-trichloroethane or a blend of trichlorotrifluoroethane and hexane is suitable. The liquid medium will separate the cracked components because of the differences in density of the various components. The hulls will sink in the liquid, and the germ and kernel floats or remains suspended in the liquid. The germ and kernel is then decanted from the hulls, the oil and liquid solvent is separated from the solids by a filter and the oil is extracted from the liquid solvent.

Abstract: Hollow microspheres having thin and very uniform wall thickness are useful as containers for the deuterium and tritium gas mixture used as a fuel in laser fusion targets. Hollow microspheres are commercially available; however, in commercial lots only a very small number meet the rigid requirements for use in laser fusion targets. Those meeting these requirements may be separated from the unsuitable ones by subjecting the commercial lot to size and density separations and then by subjecting those hollow microspheres thus separated to an external pressurization at which those which are aspherical or which have nonuniform walls are broken and separating the sound hollow microspheres from the broken ones.

Abstract: Articles having a first specific gravity may be separated from articles having a second specific gravity by placing said articles in an environment having a specific gravity between the specific gravities of the articles to be separated and thereafter subjecting the articles to pressure waves preferably of an ultrasonic frequency and having an intensity sufficient to initiate movement of said articles in the environment. The articles with the high specific gravity migrate downwardly while the lower specific gravity articles migrate upwardly to the surface where they may be removed.