摘要:

The thermal desorption of molybdenum(VI)-oxide from an inorganic adsorber matrix is an efficient new procedure for the final purification of fission molybdenum from inorganic and organic impurities. The investigations presented in this paper served to find out suitable thermally resistant inorganic ion exchangers and practical loading conditions for the preceding chromatographic sorption of molybdate anions from the process solution, in batch distribution experiments the influence of HN03-molarity, Mo-concentration and molybdenum loading on the Mo-sorption of AI2O3, Sn02, Mn02and Sb2O5is described in terms of their retention capacities and distribution coefficients. It could be confirmed that the retention capacity - as expected -depends strongly on the specific surface area, crystallinity and acidity of the oxide. AI203and Sn02with capacities of 30 and 4.7 mg Mo/g ion exchanger, respectively, proved to be superior to Mn02 and Sb205owing to their faster Mo-sorption and better stability against abrasion.

ISSN:0736-6299    

DOI:10.1080/07366298808917972

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The extraction of phosphoric acid with isoamyl alcohol from aqueous solutions relevant to and produced by leaching of phosphatic iron ore by nitric acid has been studied. The results indicate that the extraction of phosphoric acid is not temperature dependent in the range 25–40°C, and that it increases with increasing the concentration of HNO3or H2SO4. The salting-out effect of the different nitrate salts on the extraction of phosphoric acid is found to be in the order of Mg2+> Ca2+> Na+> NH+4K+. The presence of Fe3+and Al3+may reduce the extraction of phosphoric acid. Phosphoric acid can be extracted selectively against the different nitrate salts but nitric acid is coextracted. The excess coextraction of nitric acid from the aqueous phase will result in the precipitation of some phosphate complexes of Fe, Al, Ca, etc. Some tests of the continuous multistage extraction were also performed and a flowsheet for the recovery of the phosphoric acid is suggested.

ISSN:0736-6299    

DOI:10.1080/07366298808917973

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The extraction of nitric acid from concentrated phosphoric acid solutions by methyl isobutyl ketone (MIBK) dissolved in aromatic diluent has been studied. Nitric acid can be effectively removed by MIBK from the solutions containing 50–75% H3P04. With increasing the concentration of either H3PO4or MIBK, the distribution coefficient of HN03increases but the separation factor for HN03against H3PO4decreases. However, it is possible to achieve a complete removal of HN03in a few of stages and the coextraction of H3PO4can be limited to less than 1%.

ISSN:0736-6299    

DOI:10.1080/07366298808917974

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The extraction of HNO, by N,N-dialkylbutanamides is investigated by distribution measurements and IR spectroscopy. A mechanism involving the competing formation of three adducts is proposed : (HNO3,)(Amide)2(HNO3,)(Amide) and (HNO3,)2,(Amide), for which the equilibrium constants for 1M amide are respectively : 0.054, 0.086, 1.35.10-5for DOi.BA and 0.043, 0.135, 5.7.10-5for DOBA. The IR spectra show, in every species, hydrogen bonds linking amide and acid. From these results and previous works on inorganic acids extraction by other ligands such as diamides and TBP, we suggest an interpretation of the acids extraction, according to the relative basicities of water, acid anion and neutral organic extractant.

ISSN:0736-6299    

DOI:10.1080/07366298808917975

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Three sulfur-containing methylphosphonates, dibutyl propylthiomethylphosphonate, (C4H8O)2P(0)CH2SC3H7,(DBPTMP),dibutyl propylsulfinylmethylphosphonate, (C4H90)2P(0)CH2S(0)C3H7, (DBPSiMP) and dibutyl propylsulf onylmethylphosphonate, (C4H8O)2P(0)CH2S(0) C3H7(DBPSiMP) were synthesized. The extraction of gold(III), palladium(II) and platinum(IV) from HCl media with the synthesized compounds and dibutyl 2-keto-3-methylbutyl-phosphonate, (C4H8O)2P(0)CH2C (0) CH(CH3) CH3, (DBKPP) was investigated at various mixing times and acidities. DBPTMP and DBPSiMP were found to provide nearly quantitative extraction of Au(III) and Pd(II) with short equilibration times for Pd(II) extraction. DBKPP was selective for Au(TII) over Pt(IV) and Pd(II) at high acidity. The behavior of these extractants was also examined in comparison with the corresponding monofunctional extractants, dibutyl butylphosphonate(DB‘BP’), tributyl-phosphate(TBP), dioctylsulphide(DOS) and dioctyl-sulphoxide(DOSO).

ISSN:0736-6299    

DOI:10.1080/07366298808917976

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Studies at the Idaho National Engineering Laboratory (INEL) are in progress to evaluate the latest generation of bidentate organophosphorus actinide extractants. The Idaho Chemical Processing Plant (ICPP) dissolves defense nuclear fuel in a mixture of hydrofluoric and nitric acids to recover unspent uranium. Therefore, the waste stream is both acidic and has a high concentration of Zr and Al complexed fluoride. The focus is on octyl(phenyl)-N,N-diisobutylcarbamoyl -methylphosphine oxide (CMPO) as it may exhibit large actinide separation factors compared to bulk waste constituents such as Zr and Al.

ISSN:0736-6299    

DOI:10.1080/07366298808917977

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The race of extraction of plaCinum(II) wich diphenylthiourea (DPTU) into chloroform has been evaluated as a function of [DPTU]0, [Cl] and the solution pH at 25° C. The homogeneous chemical reaction:

ISSN:0736-6299    

DOI:10.1080/07366298808917978

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The extraction of Fe(II) from 0.1M NaClO4. by 2-(2'-thiazolylazo)-4,6-dimethylphenol (TADMP) and 2-(4 ', 5'-dimethy1-2’-thiazolylazo)-4,6-dimethylphenol (DMTADMP) dissolved in chloroform has been studied by distribution methods. The experimental data, treated by both graphical and numerical methods, may be explained by assuming the formation of the species FeRClO4. (logK1011= 7.58±0.09 and 9.58±0.10) and FeR2logK1020. = 14.31±0.22 and 15.32±0.18) for Fe(II)-TADMP and Fefll)-DMTADMP systems, respectively.

ISSN:0736-6299    

DOI:10.1080/07366298808917979

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0736-6299    

DOI:10.1080/07366298808917980

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The review generalizes the results on the extraction of actinides, lanthanides and other elements from alkaline and carbonate solutions with the extractants of various classes. It discusses the mechanisms of the processes and practical possibilities of the separation of elements in alkaline solutions.

ISSN:0736-6299    

DOI:10.1080/07366298808917981

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor