Stripping of Fe(III) from the Loaded Mixture of D2EHPA and TBP with Sulfuric Acid Containing Reducing Agents

Abstract

Solvent extraction of Fe(III) from chloride solution by using a mixture of D2EHPA (Di-(2-ethylhexyl)-phosphoric acid) and TBP (Tri-butyl phosphate) and the reductive stripping of Fe(III) from the loaded organic were investigated. Quantitative extraction of Fe(III) from the solution (Fe concentration = 90 g/L) was accomplished in two cross-current extraction stages by using the mixture of D2EHPA and TBP. In order to facilitate the stripping efficiency, a reductive stripping method was employed by using H 2 SO 3 or Na 2 SO 3 as a reducing agent. The addition of H 2 SO 4 into reducing agents led to improvement in the stripping efficiency while high concentration acid would suppress it. Both of the mixtures of H 2 SO 4 + H 2 SO 3 and H 2 SO 4 + Na 2 SO 3 showed good efficiency for the stripping of Fe(III), while the latter was recommended as the stripping solution based on the economics and experimental condition.

Pre-Reducing Process Kinetics to Recover Metals from Nickel Leach Waste Using Chelating Resins

“…In acid medium with sulfuric acid, sodium sul te reacts with H + to form H 2 SO 3 , as presented in Equation (4), in which k 1 1.54 × 10 −2 and k 2 1.02 × 10 −7 . Besides, sodium dithionite and sodium sul te are di erent, and both dissociate to form sodium bisul te, which is the main responsible for the reducing process in solution, but sodium dithionite also dissociates to form sodium thiosulfate [27,[34][35][36][37].…”

“…Nevertheless, sodium sulfite is a reducing agent that can be used in acid solutions. Liu et al studied reductive stripping of ferric iron using sulfuric acid and sodium sulfite [27]. Luo et al studied atmospheric leaching of nickel limonite with sulfuric acid using sodium sulfite as a reducing agent to facilitate nickel extraction, comparing the leaching process using only sulfuric acid.…”

Modeling the liquid–liquid extraction equilibrium of iron (III) with hydroxyoxime extractant and equilibrium-based simulation of counter-current copper extraction circuits

“…The reason for this is that iron (III) forms polynuclear complexes with the extractant molecules in the bulk organic phase (Smith et al, 2003), and the polynuclear complex iron cannot enter the interface between the aqueous and organic phases. Special measures such as the addition of reducing agents to the stripping acid (Liu et al, 2014) or utilization of oxalic acid as a stripping agent (Zhang et al, 2016) may be needed to improve the stripping efficiency. However, development of a method for the complete stripping of iron (III) from a loaded hydroxyoxime extractant is beyond the scope of the current study.…”

Recovery of Zn as ZnO from Steelmaking Waste Materials by Mechanochemical Leaching, Solvent Extraction, Precipitation, and Thermal Decomposition Route

“…Studies devoted to investigate the Fe (III) problem in leach solutions and loaded organic extractant were discussed comprehensively [40]. Galvanic stripping [60][61][62], reductive stripping in vacuum [63], and stripping with sulfuric acidcontaining reducing agents [64] are some of the methods applied for the removal of Fe(III) from loaded D2EHPA. Another approach for the processing of Fe-bearing leach solutions is the precipitation of Fe in the leach solutions as Fe(OH) 3 [52], jarosite [65], and hematite [66] prior to the solvent extraction process.…”