Chromium cation exchange resins

The second aliquot was passed onto another cation exchange resin and eluted as before, the effluent solution was passed onto a second cation exchange column, and the elution process was repeated. No dark band was left on the second column, and analysis of a portion of the new effluent solution showed that there had been no further loss of chromium on passage through the second column. Two additional portions of the last-mentioned solution were withdrawn for examination. The first portion was analyzed for oxalate, as before, and chromium-oxalate ratios of 1.00 to 1.02 were obtained. The spectrum of the second portion was measured through the visible range and found to agree well with the spectrum of the mono-oxalatotetraaquochromium (III) ion at the same chromium concentration. 

Catalytic reduction, with Adams platinum oxide catalyst, 470 with copper-chromium oxide, 873 with Raney nickel, 566 Cation exchange resin, for esterification, 381, 387, 388 Cellosolve, 170, 265, 444 butyl, 170, 444 methyl, 170, 444 Cellulose, 458 ... 

Toxic trace elements were isolated from water samples by extraction with di-ethyldithiocarbamate (Table 2.1.2). Following this pre-concentration step the metal ions were adsorbed on a cation-exchange resin using a mixture of tetrahydro-furan-methylglycol-6 M HCl as sorption solution. The succesive elution was treated with 6 M HCl, 1 M HCl and 2 M HNO3 for fractional separation. In another application hexane-isopropanol-HCl mixture was used as the adsorption medium An analytical scheme which provides quantitative results, is described for ion-exchange separation of fifteen major, minor and trace elements in silicates For concentration and separation of copper, chromium, lead and iron an ion-exchanger in phosphate or OH -form was used in various combinations ... 

Simple chromatographic separation of differently-charged chromium(III) complexes by ion chromatography using a column packed with an aqueous slurry of cation-exchange resin beads to form a... 

A solution containing 0.319 g of C1CI3 6H2O was passed through a cation-exchange resin in the acid form, and the acid liberated was titrated with a standard solution of NaOH. This required 28.5 ml of 0.125 M NaOH. Determine the correct formula of the chromium(m) complex. 

Chromium oxide s. Chromium trioxide. Manganese-chromium-zinc oxide Chromium(ll) sulfate—cation exchange resin 14,137 Chromium trioxide s. Chromic acid... 

In liquid-phase purification, the pnrity with respect to metal impnrities initially present in the mixtnre is improved simnltaneonsly with that with respect to nondiamond carbon. The content of impnrities of chrominm componnds introduced with the purification decreases in the alkaline treatment based on a better solubility of the amphoteric chromium compounds in a weak alkaline solntion rather than in an acid, and also by the treatment with ion-exchange resins (in particular, cation-exchange resins). 

The solution and precipitate were separated by filtration. Qualitative analysis of the precipitate showed that it contained cerium(III) and sulfate ion. [No precipitate appeared when m-bisoxalatodiaquochromate(111) ion and cerium(IV) were allowed to react at this acidity under conditions where the sulfate and/or cerium concentrations were somewhat lower.] The filtrate, including washings, was diluted to a measured volume, and two measured aliquots of this solution were withdrawn for study. The first aliquot was passed onto a cation exchange column in the hydrogen form. Elution with 1M sulfuric acid left a small dark violet band of hexaaquochromium(III) ion at the top of the column, while the rest of the chromium passed through the column. [In separate experiments it was confirmed that the Cr(OH2)fe+3 ion is retained as a dark violet band at the top of the resin when the resin is eluted with 1M sulfuric acid. This is in agreement with the observations of King and Dismukes (23).] Analysis of the effluent solution showed that 4 to 5% of the chromium had been retained by the column. 

Ion exchange is used in the metal plating industry to purify rinse water and spent plating bath solutions. Cation exchangers ranove cationic metal species, such as Cu, from such solutions. Anion exchangers remove anionic cyanide metal complexes, such as Ni(CN), and chromium(VI) species, such as CrOI. Radionuclides can be ranoved from radioactive and mixed radioactive/ hazardous chemical waste by ion exchange resins. 

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