The liquid-liquid extraction of zirconium(IV) from acidic chloride solutions was carried out with Cyanex 272 as an extractant diluted in kerosene. An increase of the acid concentration decreased the percentage extraction of metal, which indicates that the extraction follows ion exchange-type mechanism: MO2+(aq) + 2(HA)2(org) <--> MO (HA2)2(org) + 2H+(aq), where, M = Zr(IV); HA = Cyanex 272. The...

The origin of a rational (scientific) approach to extraction of metal values from ores with the aid of microorganisms (bioleaching) is traced. The removal by microbiological means of ore constituents that interfere with metal extraction (biobeneficiation), an outgrowth from bioleaching, is also traced. © 2004 SDU. All rights reserved.

Extensive ambient extraction of several metals from human hair compromises some assumptions concerning the binding of metals to hair and the biochemical process of metal incorporation into hair. Hair metal concentrations can reveal metal intoxications and metal deficiencies.The scalp hair selected for investigation included specimens of different colors from both sexes for various donor ages an...

Polystyrene-grafted-polyglycidol (PS-PG), a water-compatible resin, is applied for the extraction of precious metal in effluents of electroplating process. The extractions of gold (I) and silver (I) cyanide using this resin are investigated. More than 99% of gold and 99% of silver ions of the originally dissolved could be extracted from the aqueous phase to polymer phase. Recycling of the resin...

The concept of recovering minerals from seawater has been proposed as a way of counteracting the gradual depletion of conventional mineral ores. Seawater contains large amounts of dissolved ions and the four most concentrated metal ones (Na, Mg, Ca, K) are being commercially extracted today. However, all the other metal ions exist at much lower concentrations. This paper reports an estimate of ...

The extraction-separation of alkali, alkaline earth, and rare earth metal ions could be improved by using macrocyclic ligands as ion size selective masking reagents. By adding a macrocyclic ligand to the aqueous phase of a conventional chelate extraction system, the extraction of metal ions with larger ionic radii was shifted to a higher pH region. Consequently, the separation among the metal i...

To evaluate the superiority of using a task-specific onium salt (TSOS), a novel TSOS reagent 1-methyl-3-[2-(8-quinolinylaminosulfonyl)ethyl]imidazolium chloride (HmimesqCl) was synthesized, and its performance in extraction of different divalent metal cations was investigated. This TSOS reagent has both a cationic imidazolium unit and an anionic (proton-dissociable) complexation unit for the ex...

The solvent extraction of rare earth metal ions from nitrate solutions by 5.11.17.23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-dihydroxycalix[4]arene (L) in 1,2-dichloroethane has been investigated. The alalysis of the extraction equilibrium obtained from a mixture of La3+, Eu3+, Er3+ and Y3+ revealed that the extracted species hav...

Green chemical engineering recognises the concept of developing innovative environmentally benign technologies to protect human health and ecosystems. In order to explore this concept for minimizing industrial waste and for reducing the environmental impact of hazardous chemicals, new greener approaches need to be adopted for the extraction of heavy metals from industrial waste. In this review,...

background: the aim of this study was to determine bioavailability heavy metal concentrations of cu, cd, cr, co and zn and health risk assessment in different types of klang district, selangor (malaysia) urban surface soil using in physiologically based extraction test in vitro human digestion model. methods: a total of 76 urban surface soil was sampled based on seven different types of land us...