Process for treating brine recovered from a coal seam gas operation

摘要

A method is provided for treating brine recovered from a coal seam gas operation. The process entails directing brine recovered from a coal seam gas operation to a mixed reactor and mixing an alkaline earth reagent with the brine. This results in the precipitation of alkaline earth salts and silica, which form alkaline earth salt crystals having silica adsorbed thereto. Thereafter, the alkaline earth salt crystals and adsorbed silica are directed to an evaporator that produces a concentrate having the alkaline earth salt crystals and adsorbed silica.

主权项

1. A method of treating brine recovered from a coal seam gas operation, comprising:
a. providing the brine recovered from a coal seam gas operation wherein the brine contains silica; b. directing the brine to a mixed reactor; c. in the mixed reactor, mixing an alkaline earth reagent with the brine; d. in the mixed reactor, precipitating alkaline earth salts and silica from the brine and forming alkaline earth salt crystals having silica adsorbed thereto; e. directing the brine, alkaline earth salt crystals and adsorbed silica to an evaporator and concentrating the brine in the evaporator and producing a distillate and a concentrate having the alkaline earth salt crystals and adsorbed silica; f. circulating the brine from the mixed reactor through a contact heater and back to the mixed reactor and wherein circulating the brine through the contact heater includes directing the brine downwardly through a portion of the contact heater; g. directing steam from the evaporator to the contact heater; and h. stripping CO2 from the brine in the mixed reactor and increasing the pH of the brine in the mixed reactor by directing the steam from the evaporator upwardly through the contact heater and contacting the downwardly moving brine.