Patent ID: 8877690
Filing Date: 2014-11-04
Classification: C01B,C01D,C01F,C02F

Abstract:
1. A method of treating a gas well hydrofracture flowback and/or production wastewater (production wastewater), comprising: contacting a production wastewater with a source of sulfate ions to form one or more metal sulfates; precipitating the one or more metal sulfates from the production wastewater; removing the one or more precipitated metal sulfates from the production wastewater to form a wastewater brine that is substantially free of precipitated metal sulfate, the wastewater brine comprising sodium, magnesium, strontium, and calcium chlorides; evaporating the wastewater brine in an evaporator to form water and evaporation products, the evaporation products comprising crystalline sodium chloride and a liquor comprising from about 25% by weight to about 60% by weight calcium chloride based on the total weight of the liquor; filtering the evaporation product to form a retentate comprising crystalline sodium chloride, and a filtrate comprising the liquor; washing the retentate with saturated sodium chloride brine; drying the washed retentate; and transferring the filtrate comprising the liquor to a storage tank.