In this paper, gold leaching of a refractory sulfide concentrate by chloride–hypochlorite solution was investigated and effects of stirring speed, temperature and particle size on the leaching rate were reported. Experimental data for leaching rate of gold were analyzed with the shrinking–core model. Results were consistent with chemical reaction control mechanism in the first 1 h of leachin...

Maltogenic amylase (Mag1) is a potent enzyme that hydrolyzes the glycosidic bond of polysaccharides to produce malto-oligosaccharides (MOS). However, Mag1 has poor stability and reusability, leading inefficient MOS production. Enzyme immobilization promising method solve problem. Entrapment encapsulation technique was used in this study immobilize because high biocompatibility prevention degrad...

This study investigated the optimum conditions for the leaching of manganese-rich iron ore for subsequent beneficiation studies in laboratory scale. The experiments were carried out by varying the concentration of H2 SO4 solution and the leaching temperature. The properties of the iron ore was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM)...

Vanadium recovery of Thermal Power Plant Ash (TPPA) is an attractive process which simultaneously satisfies the pollution control standards regarding TPPA disposal and provides a valuable source of vanadium for industrial demands. In the present research work, sulfuric acid leaching route has been employed for vanadium recovery from an Iranian TPPA. Effects of acid concentration, temperature, a...

In Canterbury land-use intensification, particularly irrigated dairy expansion, is occurring on stony soils. Concerns exist about the ability of these soils to sustain intensified land-use, while maintaining nutrient leaching within discharge limits. Environmental models consistently predict stony soils as having a high vulnerability to leaching under intensive land use, but there is little exp...

Bacterial leaching of an As-containing pyrite concentrate produced acidic (pH < 1) leachates. During the leaching, the bacteria solubilized both As and Fe, and these two elements were distributed in solution-phase and solid-phase products. Jarosite and scorodite were the exclusive crystalline products in precipitate samples from the bacterial leaching of the sulfide concentrate.

Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008), depending on the water content of the soil and water movement through the soil. Ammonium forms of N can be fixed (Kissel et al., ...

Protein hydrolysate (PH) was prepared from the defatted cottonseed cake by using immobilized or native trypsin on polyamide (nylon 6,6) matrix using glutaraldehyde coupling under the controlled conditions of pH and temperature. Immobilization of trypsin on nylon beads retained 30% of the free enzyme activity and was stable against leaching for more than 30 days. Foaming and emulsification prope...

In this paper, the composite additive of CaF2/CaO was used to extract vanadium from stone coal, and the effect of roasting and leaching kinetics were studied. The purpose of this manuscript is to realize and improve the vanadium recovery from stone coal using the composite additive. The experimental results indicated that the roasted clinker can be obtained under the conditions of CaF2/CaO at a...

Reduction of migration of fecal coliforms (FC) and streptococci (FS) by limiting the leaching in effluent-irrigated soil was tested in lysimeters packed with quartz sand without or with added biosolids compost or with one of two clayey soils. The 200-L, 70-cm-deep lysimeters were either planted with a Eucalyptus camaldulensis or an Oroblanco citrus tree (in the sand only), or not planted. The E...