Selective leaching of nickel matte high (selective leaching method of high nickel matte ) by selectively leaching nickel matte agent of the high nickel, high nickel gun drilled into the processing method and the extracted solution. In the leaching process, copper, iron and precious metals and the like remain in the leaching residue is separated from the nickel and cobalt. According to the leaching agent used, it can be divided into sulfuric acid selective leaching, chlorination leaching and ammonia solution leaching (see figure). This method was developed after the 1960s. It is a promising high-nickel niobium treatment method because it combines the separation and refining of metals to simplify the process and contribute to environmental protection.
Selective leaching of sulfuric acid
A leaching method combining atmospheric pressure and pressure is usually employed. From high nickel niobium to the production of metallic nickel, it is generally subjected to processes such as grinding, leaching, purification, electrolytic deposition or pressurized hydrogen reduction. During the leaching process, nickel and cobalt in the high nickel bismuth form soluble sulfate into the solution, and copper, iron and precious metals remain in the leaching residue. Since the content of impurities such as copper and iron in the leachate is very low, the purification of the leachate is relatively simple, and it can be purified by chemical precipitation (see precipitation) or solvent extraction.
The purified nickel sulfate solution is produced by electrolytic deposition to produce nickel or by pressurized hydrogen reduction to produce nickel powder. This method has certain requirements on the content of copper and sulfur in the material, because in the hot press leaching stage, sufficient copper ions must be interacted with nickel sulfide to completely leaching the nickel in the nickel crucible into the solution.
The Outokumpu Oy Harjavalta smelter was the first to use a sulfuric acid selective leaching process to treat high nickel bismuth. The process was used in production in 1960 and the leaching system was carried out in 1981. The transformation was carried out to form a three-stage atmospheric pressure leaching process and a pressure leaching process. The leachate is decobalted with trivalent nickel hydroxide, and the purified nickel sulfate solution is sent to electrolytic deposition to produce high quality cathode nickel. The process of this method is simple, the metal direct yield is high, but the energy consumption is large.
China has tried to use the sulfuric acid selective leaching method to treat the high nickel bismuth produced by Jinchuan Nonferrous Metals Co., Ltd., and completed the semi-industrial test in 1984. The chlorination leaching uses hydrochloric acid or chlorine as a leaching agent to dissolve the nickel, cobalt and a part of copper and other valuable metals in the high nickel bismuth into the solution in the form of chloride, and most of the copper and precious metals remain in the leaching slag. From high nickel niobium to the production of metallic nickel, it is generally subjected to processes such as grinding, leaching, purification, electrolytic deposition or pressurized hydrogen reduction. The chlorination leaching is characterized by high reaction speed and large solubility of chloride. High-current density can be used in electrolytic deposition of cathode nickel, and the production capacity is large.
The Kristiansand nickel refinery at Falcon-bridge Nickel Mines Ltd. was the first to use a chlorinated leaching plant. In 1968, the process was put into production, first with hydrochloric acid leaching, and in 1977 with chlorine leaching. . The process of this method is short, can be carried out under normal temperature and normal pressure, and has strong adaptability to materials, but needs corrosion-resistant equipment.
China has also tried to treat high-nickel niobium produced by Jinchuan Nonferrous Metals Co., Ltd. with chlorine selective leaching. In 1991, the expansion test was completed, and the leaching residue contained less than 3% nickel. Ammonia solution leaching from Western Mining Corp. Ltd's Kwinana nickel refinery is the only plant in the world that uses a pressurized ammonia solution leaching process to treat high nickel bismuth. This method is produced in the year. The product is pressurized hydrogen reduced nickel powder. From high nickel bismuth to nickel powder obtained, it is generally subjected to grinding, leaching, ammonia removal, copper oxidative hydrolysis, pressurized hydrogen reduction and the like. The advantage of this method is that it can be leached in an alkaline medium at a lower temperature and pressure, and the problems of equipment structure and corrosion prevention are easier to solve. However, there are also problems such as slow leaching speed, large equipment, and low recovery rate of drills (generally 50% to 70%). This method is suitable for the treatment of high nickel niobium with a low precious metal content and a low copper content.
Pump Series,Centrifugal Water Pump,Transfer Pump,Oil Transfer Pump
Jiangsu Qiantu Trading Co., Ltd. , https://www.jsqiantupump.com