SYNTHESIS OF NICKEL SULFATE FROM RELEACH SOLUTION OF MIXED HYDROXIDE PRECIPITATE (MHP) AND PURIFICATION OF PREGNANT LEACH SOLUTION BY SOLVENT EXTRACTION USING VERSATIC 10 AND CYANEX 272

• Main Author: Muliansyah, Fajar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/57904
• Institution: Institut Teknologi Bandung

The development of the electric car market has increased the demand for nickel sulfate. Nickel as nickel sulfate hexahydrate is one of the precursor materials for lithium ion battery cathodes used for batteries in electric cars. The NiSO4 synthesis process is generally carried out through crystallization of sulfate solutions with high nickel content. Various parameters that are regulated in the NiSO4 crystallization process can affect the recovery of NiSO4 crystals such as crystallization rate and purity. In this study, the effect of the NiSO4 crystallization process on the rate of crystallization of Ni and the Ni content on the crystals were studied. In addition, Ni content on the crystals resulting from the crystallization process of samples that went through the extraction stage using Cyanex 272 was also compared with the extraction stage using Ni-Cyanex 272. In this study, samples were prepared by releaching of Mixed Hydroxide Precipitate (MHP) and purification of the pregnant leach solution by solvent extraction using Versatic 10 and Cyanex 272. The sample preparation process removes impurities and generates precursor solution that has high purity of nickel. Series of crystallization experiments were carried out by varying the processing time, %seed, initial pH of the solution, and process temperature at a certain level. The metal concentrations in the sample, residual solution, and product were analysed using Atomic Absorption Spectroscopy (AAS) to study the effect of each variable on the crystallization rate and the Ni content on the obtained crystals. The investigation that has been done shows the rate of Ni crystallization increases with time, %seed, and temperature, while the pH of the solution does not show any effect on the crystallization rate. The crystallization rate can be derived from zero-order reaction kinetics with a reaction rate constant of 64.83 mg/hour. For the Ni content of the obtained crystal, based on the results obtained, the variables tested in this study did not affect the Ni content when all the solvent has been evaporated. In addition, the sample prepared by the extraction step using Ni-Cyanex 272 was able to provide higher levels of Ni in the crystal than the sample extraction using Cyanex 272. The results of the crystallization experiment showed a process time of 11 hours, %seed by 25%, initial pH of solution of 5, and a process temperature of 80oC gave the best results on the rate of Ni crystallization rate.