Abstract: A method of flocculating coal fines from produced water that includes the steps of: (A) mixing at least: (i) produced water, wherein the produced water comprises suspended coal fines; (ii) one or more oil-soluble phosphate esters; and (iii) water-immiscible solvent; wherein the mixing is in proportions to obtain an oil-in-water emulsion; (B) allowing or mechanically causing the oil-in-water emulsion to substantially break into: (i) a first fluid having a continuous phase comprising at least some of the water from the produced water; and (ii) a second fluid having a continuous phase comprising at least some of the water-immiscible solvent; and (C) mechanically separating the first fluid and the second fluid. Optionally, the step of mixing further includes mixing with a crosslinker for the one or more phosphate esters to form a gel for suspending the separated coal fines.

Abstract: A method of flocculating coal fines from produced water is provided. The method includes the steps of: (A) mixing at least: (i) produced water, wherein the produced water comprises suspended coal fines; (ii) one or more oil-soluble phosphate esters; and (iii) water-immiscible solvent; wherein the mixing is in proportions to obtain an oil-in-water emulsion; (B) allowing or mechanically causing the oil-in-water emulsion to substantially break into: (i) a first fluid having a continuous phase comprising at least some of the water from the produced water; and (ii) a second fluid having a continuous phase comprising at least some of the water-immiscible solvent; and (C) mechanically separating the first fluid and the second fluid. Optionally, the step of mixing further includes mixing with a crosslinker for the one or more phosphate esters to form a gel for suspending the separated coal fines.