The effect of mechanical activation on the kinetics of ammoniacal thiosulfate leaching of a refractory oxide gold ore containing 2.8 ppm Au was investigated. The gold extraction of 99.81% was achieved by 16 h leaching of a sample mechanically activated for 60 minutes. The gold extraction observed for a similar reference sample without mechanical activation was only 55%. Studies revealed that le...

Processing of anodic slimes from an Egyptian copper electrorefining plant, exhibiting high contents of copper, lead, tin and silver has been presented. The proposed hydrometallurgical process consists of two leaching stages for extraction of copper with H2SO4 – O2 and silver with thiourea – Fe. Pyrometallurgical treatment of the leaching solid residue for production of Pb-Sn soldering alloy was...

In present investigation the biological leaching of aluminum by isolated fungi from red mud, the main waste product of the alkaline extraction of Al from bauxite was studied. Biological leaching experiments were carried out using indigenous, date and orange specimen fungi, Aspergillus Niger, Penicillium simplicissimum notatum. Savored Dextrose chloramphenicol Agar (SDA) wa...

Leaching of a low-grade lead and zinc oxide ore was studied by an organic reagent, citric acid. The quadratic mathematical models were developed for the relationship among the influential parameters and lead and zinc recoveries. Leaching rate was strongly affected by the interactive effects of factors. It was also found that the quadratic effects of stirring speed and linear<e...

An experimental study was conducted to determine the effects of the leaching parameters on impurity ion concentrations of the liquid phase in ulexite leaching. Powdered ulexite ore was leached in an aqueous medium with sulfur dioxide. The Taguchi experimental design approach and statistical methods were used to evaluate the effects of the leaching parameters (solid/liquid ratio, temperature...

Processing of gold ores with high sulfide minerals is problematic as they consume cyanide and reduce gold leaching. Optimization of gold leaching and cyanide consumption requires a methodology to estimate the amount of exposed cyanicides, their leaching kinetics, and speciation of cyanide complexes that consume the free cyanide and compete with gold. In this paper, a physico-chemical approach i...

7.03.3 SOURCES AND DIAGENESIS OF SHOAL-WATER CARBONATE-RICH SEDIMENTS 75 7.03.3.1 Sources of Shoal-water Carbonates 75 7.03.3.1.1 General considerations 75 7.03.3.1.2 Sources of carbonate muds 76 7.03.3.1.3 Formation of carbonate sands 76 7.03.3.2 Early Marine Diagenesis of Shoal-water Carbonate-rich Sediments 77 7.03.3.2.1 Pore-water chemistry 77 7.03.3.2.2 Precipitation of early carbonate cem...

Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Sporosarcina pasteurii (S. pasteurii) bioremediation by mixing method was used soils lead (Pb), zinc (Zn) and cadmium (Cd). A significant reduction of metal leaching concentrations observed in S. bio-treated samples. Furthermore, urease hydrolyzing bacteria have addition...

Calcium vanadate (CaV2O6), a new product of vanadium precipitation, was obtained from slag by sodium roasting-water leaching and calcium precipitation. The separation behavior silicon in during roasting water systematically studied, micro-morphology valence migration Fe slag, residue were revealed. Na2CO3 added to the at 20% mass fraction, roasted 790 °C, kept for 120 min, sample deionized aque...

Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such result leaching calcium aluminate slags with solutions, in accordance Pedersen process, which is an alternative process for alumina production. The concentration ions solution revealed as a key ...