Our Process
Westwin converts intermediate nickel, cobalt, and manganese feedstock into class 1 metal and pCAM products. The process starts with the input of intermediates, like mixed hydroxide precipitates (MHP), high grade nickel matte (HGNM), and black mass, through a feed preparation circuit, then through a carbonyl circuit where Westwin vaporizes impure nickel units as a refining process. Post refinement and decomposition in the carbonyl circuit, Westwin then inputs the high purity nickel powder into a hydrometallurgical dissolution circuit to produce nickel sulfate. Westwin feeds nickel sulfate, cobalt sulfate, and manganese sulfate into its pCAM co-precipitation circuit
Carbonyl Process History
1890: Discovery of Nickel Carbonyl: Nickel carbonyl was discovered by Mond and his co-workers, sparking interest in the unique properties of volatile metal carbonyls. 1902: First Carbonyl Nickel Refining Plant: The Mond Nickel Company Ltd built the first carbonyl nickel refining plant in Clydach, South Wales, to produce high-purity nickel pellets. 1920s: INCO Acquires Mond Nickel Plant: The International Nickel Company (INCO) acquired the Mond Nickel plant, continuing its operations. 1939-1945 (World War II) Production of Nickel Powders: INCO started producing nickel powders for components of batteries and special alloys used by the navy and army. 1960s: Soviet Union Carbonyl Refinery: The Soviet Union built its only nickel carbonyl refinery, Norilsk Nickel Kola MMC, with a capacity of 5,000 tonnes per year. 1973: Second Carbonyl Plant in Sudbury, Canada: INCO opened a second carbonyl plant in Sudbury, Canada, producing high-purity nickel products, including pellets and powders, and piloting the production of nickel foams and nickel-coated carbon. 2006: Vale SA Acquires INCO: Brazilian mining giant Vale SA acquired INCO, shifting the company's strategy to streamline production and reduce the number of nickel products from over twenty to just four. 2000s: Chinese Development of Carbonyl Technology: Two Chinese companies, Jinchuan Group Company and Jilin Jien Nickel, began developing carbonyl technology. 2007: Jilin Nickel Carbonyl Plant: Jilin Jien Nickel commissioned its Nickel Carbonyl plant with a capacity of 2,000 tonnes per year, followed shortly by an iron carbonyl operation. 2015: Jinchuan Group Carbonyl Plant: Jinchuan Group Company started operating a plant with a capacity of 10,000 tonnes per year. Present Day: Chinese Expansion in Carbonyl Technology: At least two more Chinese companies, Tianyi and Yuelong Powder, are now using carbonyl technology.
Overview of pCAM
pCAM production Nickel sulfate liquor from the dissolution step is the starting electrolyte for this operation. Since the pCAM product is a molar ratio of 8Ni / 1Co / 1 Mn, cobalt sulfate salt and manganese sulfate salt will be added to this nickel sulfate solution in the correct ratio prior to the pCAM precipitation. Demineralized water may be added to adjust the liquor concentration going to the precipitation reactor. In the precipitation step, pH control, level of agitation, temperature, and residence time are important parameters to achieve the optimum particle morphology and activity. Both caustic (NaOH) and ammonium (NH4OH) are used in the correct ratio as bases to form the hydroxide precipitate. The reactor discharge, a slurry of precipitated Ni/Co/Mn hydroxides, is thickened, with a small portion of the thickener underflow recycling to the reaction vessel to control proper particle size, with the mainstream thickener underflow going to a pressure filter press to collect the solids in the form of a filter cake. The thickener overflow containing a small number of suspended solids is polish filtered in a pressure filter to ensure no loss in metals. Both solids free streams from the thickener overflow and the main filter cake filtrate, containing the neutralization by-product sodium sulfate (Na2SO4) soluble salt are directed to waste effluent treatment for disposal. The moist filter cake, nickel/cobalt/manganese hydroxide, Ni/Co/Mn (OH)2, is dried, screened, treated to magnetic separation, and packaged as supply to CAM production (where the lithium compound is added to make the final CAM product.)
Overview of Dissolution
Ni Powder Dissolution Nickel powder produced from the carbonyl process is virtually pure nickel which allows this material to be used in the production of pCAM without further purification steps. The use of “electrolytic[1]grade” sulphuric acid in the dissolving step produces a pure Ni electrolyte at ~ 100 g/l Ni as nickel sulfate. The powder dissolution takes place at ~90 C and because the reaction releases heat the temperature will be maintained by cooling. The reaction vessels, agitator, and cooling coils as well as associated pumps and piping are stainless steel to prevent corrosion and maintain the purity of the nickel sulfate liquor. At the end of the dissolution, virtually all of the Ni powder and acid are consumed resulting in ~100g/l Ni and about pH 2 at which point the solution is filtered to ensure a solids-free liquor and analyzed for purity.
