Liquid-liquid Extraction Of Zinc Research Articles

Liquid-liquid extraction of zinc from phosphoric acid solution by acid di (2-ethylhexyl) phosphoric

Abstract In this work we studied the complexation of Zn2+ in dilute and concentrated phosphoric media. The investigation method used is the liquid-liquid extraction. This method allowed us to define the nature of the zinc phosphoric species and to calculate their stability constants. These are the following entities ZnH2PO4+ and ZnHPO4, whose stability constants are respectively equal to 5.83·10−2 and 5.83·10−5. We also studied at pH and analytical concentration of H3PO4 data the effect of concentration on this complexation. In addition, the sharing data show that the chelate extracted in the organic phase is Z n X 2 , ( H X ) 2 - formed according to the reaction: Z n 2 + + 2 ( H X - ) 2 ⇆ Z n X 2 , ( H X ) 2 - + 2 H + of constant Ke = 5.12·10−3, (X = di (2-ethylhexyl) phosphoric).

Liquid-liquid extraction of zinc(II) as its ethyl xanthate

A method for quantitative extraction of zinc with potassium ethyl xanthate into carbon tetrachloride is described. The optimum conditions are: pH 5–6 and Zn(II) to reagent ~1:8 mole ratio. The effects of other ions on the extraction of Zn 2+ have been investigated, and its separation from As 3+, Pb 2+, Cu 2+ and Fe 3+is described. The possibility of repeated use of the solvent (still loaded with xanthate after the zinc has been stripped) for further extractions (after addition of a little extra xanthate) has been explored. Various stripping agents have been examined, and the optimum conditions found.

Liquid-liquid extraction of zinc and cadmium with 1,2-naphthoquinone thiosemicarbazone into methyl isobutyl ketone, and their simultaneous determination by atomic-absorption spectrophotometry

Zinc and cadmium are extracted from aqueous solution with 1,2-naphthoquinone thiosemicarbazone for simultaneous determination by atomic-absorption spectrophotometry. This compound reacts with zinc and cadmium in weakly acid medium to produce chelates which are extractable into methyl isobutyl ketone. The atomicabsorption is measured at 213.9 and 228.8nm for zinc and cadmium, respectively. The sensitivity is 0.3 ng per ml of original aqueous solution and several foreign ions are tolerated in 100-fold ratio to Zn or Cd.

The Liquid-Liquid Extraction of Zinc with Polyethylene Glycol and Poly(oxyethylene)-type Nonionic Surfactants

Abstract The Zn(II) extraction was made from its acidic thiocyanate solution, using polyethylene glycol and its mono(alkylphenyl) ether as extractants. The effects of the number of oxyethylene groups (–O–CH2–CH2–) per molecule and of the kind of the counter cation of thiocyanate on the extractability are described, together with some other factors affecting the Zn(II) extraction.

Liquid-liquid extraction of zinc from aqueous iodide solutions with 4-(5-nonyl)pyridine in benzene

Liquid-liquid extraction of zinc from aqueous iodide solutions with 4-(5-nonyl)pyridine in benzene

Liquid-Liquid Extraction of Zinc with High-Molecular-Weight Amines from Alkaline Cyanide Solutions

Abstract Quaternary amines are unique in their ability to extract metal cyanides from highly alkaline solutions. Zinc cyanide extracts essentially quantitatively at both the subnanogram and macro levels. Regeneration of the amine solvent is achieved by stripping the zinc with sodium hydroxide, sodium hypochlorite, or alkaline or acidic formaldehyde solutions. Because they readily extract free cyanide as well as anionic metal cyano complexes, the high-molecular-weight quaternary amines show considerable promise for industrial pollution abatement applications.

Liquid-Liquid Extraction of Zinc with Aliquat 336-S-Br from Aqueous Bromide Solutions

Abstract A new solvent extraction system has been developed for zinc in aqueous bromide solution using Aliquat 336-S-Br-xylene solution as an extractant. A 1 mg/ml zinc solution is extracted essentially quantitatively with an equal volume of 5% Aliquat 336-S-Br-xylene solution in 15 sec. The extracted zinc can be stripped from the nonaqueous layer with a series of aqueous solutions including Na2SO3 (≥m 1.0 M) NaOH (≥m 0.5 M), NH3 (≥m 0.5 M), ethylenediamine (≥m 0.3%), and EDTA (≥m0.5%). The extraction is quantitative only from acidic solutions. High aqueous to organic phase ratios can be utilized without loss of extraction efficiency.

Liquid-liquid extraction of zinc with Aliquat 336-S-I from aqueous iodide solutions

Liquid-liquid extraction of zinc with Aliquat 336-S-I from aqueous iodide solutions

Liquid-Liquid Extraction of Zinc with Thiothenoyltrifluoroacetone Direct Photometric Determination in the Organic Phase

Abstract The thioderivative of 2-thenoyltrifluoroacetone [1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (STTA)] is used for the simultaneous extraction and direct photometric determination of zinc. About 68 μg of zinc was quantitatively extracted at pH 7–7.5 with 10 ml of 0.001 M STTA in carbon tetrachloride as yellow green colored complex. It was measured spectrophotometrically at 450 nm. The system conformed to Beer’s law over the concentration range of 0.4 to 30 μg of zinc per ml. The color of the complex was stable for more than 96 hr. Zinc was extracted quantitatively and was determined in the presence of large excess of (1 : 300) ions which are associated with it. The method was made selective by using sequestering agents like ascorbic, oxalic, citric acids or alkali cyanide to form unextractable negatively charged complexes. The selective extraction with mesityl oxide was used to eliminate the interferences due to iron and chromium. The procedure was found to be applicable for the analysis of zinc in gun metal and brass. The proposed method is comparable with the standard methods for the extraction of zinc.