Abstract: A method and composition are provided for transporting coarse particles of coal in a dense liquid CO.sub.2 media. The dense media contains fine particles of densifying material such as coal or magnetite which form a suspension in the liquid CO.sub.2. The suspension is capable of supporting large particles of coal for transportation in a liquid CO.sub.2 slurry pipeline. Use of the dense media allows the pumping of the coarse coal particles at slower velocities than if the fine densifying particles were not present.

Abstract: A process as disclosed forming a non-agueous, free-flowing composition. The process involves treating a finely divided inorganic or organic material with liquid carbon dioxide to form a slurry. The treated material is separated from the slurry and shows suprising free-flowing, nonagglomerated behavior.

Abstract: Method and apparatus for removing heavy metals as sulfides from aqueous liquids. The aqueous liquid is introduced into a circulating liquid loop wherein there are established a mixing zone, a controlled precipitation initiating zone, a crystal growing zone and a crystal settling zone. The aqueous feed liquid containing H S dissolved therein and at a pH below that at which the sulfide is precipitated is mixed in the loop with a pH-adjusting liquid; and the degree of supersaturation with respect to the metal sulfide is maintained within the controlled precipitation initiating and crystal growing zones in the metastable condition so that the growth rate of the metal sulfide crystals remains greater than under uncontrolled conditions vis-a-vis the nucleation rate to effect the production of metal sulfide crystals of a character which makes it possible to separate them through clarification and filtration.

Abstract: Finely divided coal is slurried with liquid carbon dioxide and pumped from a source (mine, dump, railway car, etc.) to a loading pier where, after deslurrying, the coal is pneumatically carried by gaseous carbon dioxide into a storage facility or directly to a waterborne carrier. The coal is maintained under a blanket of carbon dioxide gas during storage and transport. When the waterborne carrier, which may be an ocean going vessel or an inland waterway vessel, reaches its destination, the coal is removed using carbon dioxide gas and then delivered to storage or a use point. If the use point is some distance away, the coal may be reslurried with liquid carbon dioxide and pumped to its final destination.

Abstract: Method and apparatus for removing heavy metals as sulfides from aqueous liquids. The aqueous liquid is introduced into a circulating liquid loop wherein there are established a mixing zone, a controlled precipitation initiating zone, a crystal growing zone and a crystal settling zone. The aqueous feed liquid containing H.sub.2 S dissolved therein and at a pH below that at which the sulfide is precipitated is mixed in the loop with a pH-adjusting liquid; and the degree of supersaturation with respect to the metal sulfide is maintained within the controlled precipitation initiating and crystal growing zones in the metastable condition so that the growth rate of the metal sulfide crystals remains greater than under uncontrolled conditions vis-a-vis the nucleation rate to effect the production of metal sulfide crystals of a character which makes it possible to separate them through clarification and filtration.

Abstract: Method and apparatus for transporting coal in finely divided form in a coal/liquid slurry. Liquid carbon dioxide, which can be formed by burning coal at the coal source point and liquefying the resulting gaseous carbon dioxide, serves as the slurry liquid. The slurry is pumped through a slurry pipeline to the coal use point under conditions of temperature and pressure to maintain the carbon dioxide in liquefied form. Subsequent to deslurrying, the coal-free carbon dioxide can be liquefied and returned through a liquid pipeline to the coal source point for reuse. The use of liquid carbon dioxide as a slurry medium is also applicable to transporting other finely divided solids such as ores and the like.