The molecule formula of nickel carbonate is NiCO3, and its properties are oblique light green crystals, which are decomposed above 300 C. Soluble in ammonia and dilute acid. It is insoluble in water.There are several methods for the synthesis of nickel carbonate:
1. Prepare NaHCO 3 aqueous solution saturated with CO2 and add it to flask containing NiCl2 or Ni (NO3) 2 Aqueous solution. Close the plug to prevent CO2 from escaping and keep the solution at low temperature. The precipitation formed by filtration and washing should be carried out at low temperature, and the NiCO3 product can be obtained after drying. The product obtained by this method is not pure, and it will contain some sodium salt.
2. Electrolysis of carbonated water (i.e. CO2 saturated aqueous solution) with nickel electrode. Three nickel plates are suspended on the cover of the electrolytic cell, two of which are placed at both ends of the cell (cathode) and the other in the center (anode). The pure water is added to the upper edge of the cell at a distance of 2.5 cm. The pure carbon dioxide gas is introduced into the cell. The outer part of the cell is cooled by running water. The current between the two poles is 2-2.2A, and the nickel carbonate hexahydrate is formed and deposited in the cell. At the bottom of the tank, the precipitation is filtered, and the nickel carbonate is obtained by drying at 100 C.
3. Heat the boiling nickel chloride solution to the boiling excess sodium carbonate solution, and react: after the precipitation is filtered, wash it with hot water until the Cl-ion content is qualified, and then dry it at less than 40 ~C, then wash it with hot water until the Cl-ion content is qualified, and then dry it at 25~30 ~C.