PURIFICATION OF IRON(III) FROM ARTIFICIAL SOLUTION SIMULATING FERRONICKEL LEACHING SOLUTION VIA SOLVENT EXTRACTION USING TRIBUTYL PHOSPHATE

• Main Author: Nandika Pratama, Mochammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87928
• Institution: Institut Teknologi Bandung

As a result of the growing global electric vehicle (EV) market, there has been an increased demand for EV battery materials, including nickel sulfate (NiSO?) and iron phosphate (FePO?). To meet the high demand for battery materials, alternative process routes have been developed, one of which involves converting class 2 nickel products, such as ferronickel (FeNi), into NiSO? and FePO?. One potential process route for converting FeNi into NiSO? and FePO? is by leaching FeNi in hydrochloric acid (HCl), followed by the purification of Fe from the pregnant leach solution (PLS) using solvent extraction (SX) with tributyl phosphate (TBP) as the extractant, before further processing into FePO?. Meanwhile, the raffinate, which is rich in Ni, can be processed into class 1 nickel products, such as NiSO?. This research aims to determine the optimal parameters for separating Fe from Ni and other impurities in an artificial solution simulating FeNi leach PLS in HCl using SX with TBP as the extractant. A series of SX experiments has been conducted, including determining the composition of the feed solution for SX, followed by three stages of SX experiments which include extraction, scrubbing, and stripping. The feed solution composition was determined through FeNi leaching experiments, followed by chemical composition analysis and acid titration of the resulting PLS. An artificial solution simulating FeNi PLS was then prepared as the SX feed solution. The experiment results showed that the optimum extraction of Fe(III) (93.89%) was achieved with 100% TBP at a Cl? concentration of 9 M and an O/A ratio of 2. Fe extraction increased monotonically with increasing Cl? ion concentration in the range of 7.75–9.00 M (85.20–93.89%) and increasing O/A ratio in the range of 0.25–4.00 (35.35–99.70%), with low co-extraction of Ni (0.00–1.43%), Co (0.00– 2.72%), Cr (0.00–2.26%), and Mn (1.67–4.30%). Scrubbing was considered ineffective due to low scrubbing performance for all metals at all HCl concentration variations in the range of 0.50–8.00 M. Stripping was performed using water and optimal Fe stripping performance was obtained at an O/A ratio of 0.5, which resulted in Fe stripping performance of 75.35%, and producing a stripping solution with 14.5 g/L Fe with minimal impurities (<1 ppm).