Synthesis of Calcium Carbonate Particles Modified by Coating with Nickel Precursor

CaCO3 powders were prepared by the homogeneous precipitation method using CaCl2, urea as the starting materials. Uniform CaCO3(calcite, aragonite, vaterite) powders were obtained by various conditions. The surfaces of CaCO3 powders were modified by coating them with a lithium precursor using two different precipitation techniques: homogeneous decomposition of precipitating agents(urea, NaHCO3, NH4HCO3) and forced hydrolysis in pure water. Selecting the Ni(NO3)26H2O and urea(or NaHCO3, NH4HCO3) as Ni-source and precipitating agent respectively, the NiO could be uniformly coated on the CaCO3 powder in the aqueous system. The coating NiO layer dominated the surface properties of the coated lime powders. Calcination of these nickel hydroxide crystals in air at 500°C transformed them into NiO.