Platinum, Iridium Solvent Extraction Separation Of Research

Solvent extraction is an advanced and important methord of producing platinum metals and recovering them from secondary resources. While the properties of platinum and iridium are similar, especially the extraction behavior of Pt(Ⅳ) and Ir(Ⅳ) is so close that the separation of them is difficult.But the extraction behavior of Ir(Ⅲ) and Pt(Ⅳ) is different.So we must choose the right reducer deoxidation iridium to separate platinum and iridium by solvent extiaction .Another choosing the right anti-extractant is very important to separating platinum and iridium with extracting.This paper has studied the technological conditions of to separating platinum and iridium with extracting started with sifting the reducer and anti-extractant. The finished work as follows:(1)After reading a lot of related papers and doing lots of experiments,the dibenzyldithioox-amide was chosen as the chromogenic reagent to determine platinum and 2-mercapto-benzothiazole was chosen to determine iridium by spectrophootometry . Besides the proper system of determining the platinum and the iridium by spectrophootometry has been established.(2)By reading large amount of papers and experiment examination having elected N₂₃₅ is chosen as the extractant, N-Dodecane as the diluent, isoamyl- alcohol as the modifier.In order to establish proper extractaction system, the effects of extractant concentration, HC1 concentration, modifier concentration , time of extraction had been studied. Result is indicated that when Organic media composition is compared with 8% N₂₃₅-20 % isoamyl-alcohol-C₁₂H₂₆, 1:1, acidity is 1mol/L HC1 and the extraction time is over 5 minutes, The percentage extraction of Pt( Ⅳ) achieved 97%.On the other hand in antiextraction the speed of the phase separation is quickly when Na₂CO₃-5%NaHCO₃-2% NaCl was chosed as the anti-extractant.(3)The proper reducer that NH₂OH-HCl had been chosen out to be used for reducer by determing the electric potential .On the other hand, the best deoxidation condition was established with extracton tests.(4)By comparing the extraction rate and the antiextraction rate of Pt and Ir that conontained in conteunitary platinum (Ⅳ) solution , unitary iridium (Ⅳ) solution , platinum (Ⅳ) andiridium (IV) commixture solution the conclusion can be get: that the extraction rates of Ptmaintains in about 97%, the extraction rate of Ir can be reduced to about 5%;another thephase separation was not effected by reducer. Therefore the purpose of extraction separatesPt with Ir have reached .(5)Experiment having carried out on material liquid that result demonstrates what beadopted extraction system of separating the platinum and the iridium is feasible.(6)The extraction mechanism of N₂₃₅ extracting Pt has been discussed and the extractanthas been reused.