title: Liquid-liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine.
abstract: Liquid-liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions was carried out using tri-iso-octylamine (Alamine 308) as an extractant diluted in kerosene. The percentage extraction of platinum(IV) and rhodium(III) increased with increase in acid concentration up to 8 mol L(-1). However, at 10 mol L(-1) HCl concentration, the extraction behavior was reversed, indicating the solvation type mechanism during extraction. The quantitative extraction of approximately 98% platinum(IV) and 36% rhodium(III) was achieved with 0.01 mol L(-1) Alamine 308. The highest separation factor (S.F.=184.7) of platinum(IV) and rhodium(III) was achieved with 0.01 mol L(-1) Alamine 308 at 1.0 mol L(-1) of hydrochloric acid concentration. Alkaline metal salts like sodium chloride, sodium nitrate, sodium thiocyanate, lithium chloride, lithium nitrate, potassium chloride and potassium thiocyanate used for the salting-out effect. LiCl proved as best salt for the extraction of platinum(IV). Temperature effect demonstrates that the extraction process is exothermic. Hydrochloric acid and thiourea mixture proved to be better stripping reagents when compared with other mineral acids and bases.
authors.affiliation: Metals Recovery Department, Minerals Resources Research Division, Korea Institute of Geoscience & Mineral Resources, Yuesong-gu, Daejeon, South Korea. jinlee@kigam.re.kr
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Rajesh Kumar
authors.forename: Joon-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Hyung-Kyu
authors.initials: HK
authors.lastname: Park
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Yoon
mesh_terms: D000588:Amines / Q000737:chemistry*; D006851:Hydrochloric Acid; D010984:Platinum / Q000302:isolation & purification*; D012238:Rhodium / Q000302:isolation & purification*; D012996:Solutions; D013696:Temperature; D013890:Thiourea; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D000588:Amines; D012996:Solutions; D014874:Water Pollutants, Chemical; D010984:Platinum; D012238:Rhodium; D013890:Thiourea; D006851:Hydrochloric Acid; C008699:octylamine