PROCESS FOR TREATING WATERS PRODUCED OR COLLECTED FROM THE OIL EXTRACTION IN MINING OPERATIONS AND REDUCING THE TENDENCY OF CALCIUM SCALING OF PROCESS EQUIPMENT

摘要

Oil sands process water (OSPW) is directed to an evaporator (16) that evaporates the OSPW and produces steam and a concentrated brine. The OSPW includes alkalinity and calcium hardness. To inhibit calcium carbonate scaling of the evaporator (16), magnesium oxide is mixed with the OSPW, resulting in the precipitation of magnesium hydroxide which acts as a seed material for calcium carbonate precipitation to prevent fouling. The process crystallizes the calcium carbonate and the mixture of magnesium hydroxide and calcium carbonate crystals are circulated through the evaporator (16) as well as recirculated (20) to a point upstream of the evaporator (16).