Patent ID: 8470139

Claim:
A method for treating fractionated water produced by a hydraulic fracturing process, the method comprising: decanting a fractionated water stream in at least one decanter, wherein the decanter is maintained at a temperature ranging from about 90° F. to about 120° F.; flashing the decanted water in at least one first flash tank and at least one second flash tank in fluid communication with one another to provide a residual concentrate stream, wherein the first flash tank is operated at a temperature ranging from about 180° F. to about 200° F., wherein the second flash tank is operated at a temperature ranging from about 140° F. to about 160° F., and wherein the first flash tank and the second flash tank are maintained at a vacuum pressure; evaporating the residual concentrate stream in at least one evaporator kettle to produce a concentrated brine, wherein the evaporator kettle is fluidly connected to the second flash tank, wherein the evaporator kettle is operated at a temperature ranging from about 95° F. to about 115° F., and wherein the evaporator kettle is maintained at a vacuum pressure; dewatering the concentrated brine to produce recovered salt having less about 20 wt. % water; and the recovered salt comprises from about 10 wt. % to about 30 wt. % calcium salts, from about 50 wt. % to about 90 wt. % sodium chlorida, and from about 0.01 wt. % to about 2 wt. % salts and other contaminants besides sodium chloride and calcium salts.