The Formation of Tetraethylene Pentaamine/Bentonite Composite with High Adsorption Effectiveness for Nickel Recovery from Leach Liquor

Abstract

For the recovery of nickel from Egyptian sheared serpentinized ultramafic rock leaching solution from Um Seleimat ophiolites in the southeastern desert, a composite tetraethylene pentaamine/treated bentonite (TEPA/TB) was prepared using a wet technique. Devices including SEM, XRD, FTIR, EDS, and BET were manipulated to discover more about the TEPA/TB adsorbent after it was made. Nickel ions were adsorbed for nickel chloride solution by TEPA/TB composite. The optimal Ni ions sorption parameters were 150 mg/L Ni ions by reacting 50 mg TEPA/TB with Ni ions at pH 5 for 60 minutes at 25 °C. The TEPA/TB composite was found to have excellent sorption characteristics for Ni ions in its solution, as evaluated by the nickel recovery behaviors. The highest capacity of Ni ions taken up was 132.5 mg/g. Pseudo-second-order and Langmuir's isotherm fit the sorption mechanism quite well. Ni ions sorption onto the TEPA/TB composite was found to be an exothermic, random, and spontaneous process in the thermodynamic analyses. Using 0.7 M H2SO4 for 40 minutes, Ni ions were also desorbed from Ni/TEPA/TB. In addition, after eight cycles of Ni ions adsorption-desorption, the TEPA/TB sorbent was regenerated. TEPA/TB sorbent was used to recover nickel ions for serpentine-bearing rock after dissolution to gain Ni ions leachate using 4 M HCl, a stirring speed of 275 rpm, and a 1/8 S/L ratio for 4 hours of contact time at 25 °C. Finally, the Ni ions' adsorption-desorption on TEPA/TB was applied to gain a NiSO4 solution, which was used to precipitate nickel as Ni(OH)2. The precipitate was calcined to NiO, which has a 75.83% purity level of Ni ions.