No abstract

No abstract

Sodium Cyanide (NaCN) has been used to recover gold from gold bearing ores. This work aims to develop a simulation model of leaching process by using cyanide solvent for the dissolution of gold by using HSC simulator. The results from this simulation were compared with other researcher which employed Aspen Plus and it shows very good agreement with very small error (<1.5%). The cases study was carried out using the developed process model where hydrochloric acid (HCl) was used as solvent, the effect of different concentration of Au in ores and the effect of different concentration of solvent as a leaching reagent. The results show that the chlorination process gives higher amount of gold (Au) dissolved in the solvent compared to cyanidation process. The develop process model provide an effective means for studying the solid liquid leaching process in the future.

Digestion and leaching are known as part of the main processing pre-treatment method in the extraction of rare earth elements (REEs). This work aims to carry out the sensitivity analysis of the liquid–solid (L/S) ratio, the type of acids as well as the number of reactors for the recovery of REEs, namely lanthanum (La) and neodymium (Nd) from monazite concentrate through the leaching process. A model was developed and simulated by using METSIM, a software for modelling metallurgical processes. The process was modelled as a two-step process; the first is the digestion, followed by the leaching process to produce monazite leachate. The results show that the optimum L/S ratio was 8:1 to recover the highest amount of REEs, with HCl was found to perform better as a solvent for the recovery of REEs compared to H2SO4. In addition, the optimum recovery of REEs was achieved by using three reactors, which is in the range of 70-95%.