NICKEL SULPHIDE PRECIPITATION PROCESSES

摘要

The invention provides hydrometallurgical processes by which dissolved nicke l may be removed from water at ambient temperature and low system pressure The continuous process for precipitating nickel ions from a pregnant aqueous solution comprises contacting the pregnant solution with a dissolved sulphid e in a contactor to form solid nickel sulphide under contactor conditions that comprise a contacting temperature of between 0 and 5O0C, a contacting pressu re of between 0 5 and 1 5 atmosphere, and a contacting pH of between 6 and 9, separating the solid nickel sulphide from the pregnant solution to provide a nickel sulphide sludge and a barren water solution, wherein the nickel sulphide sludge has a mean nickel particle size of at least 5 microns and th e barren water solution has a dissolved nickel concentration of less than 10 parts per million, and recycling at least a portion of the nickel sulphide sludge to the contactor