The aim of the present work is to study the kinetics of leaching process of spent catalyst Ni, Mo/Al2O3 in order to recover the molybdenum using ammonium hydroxide. The investigation depends on the results of previous work ( Mousa et al, 2012). The experiments were conducted in 1-liter stainless steel autoclave. Kinetics study showed that both the diffusion through ash layer and the reaction on...

Magnesium oxide suitable for the use in basic refractories was prepared from dolomite (CaMg(CO3)2) by hydrochloric acid leaching, precipitation with CO2 and thermal hydrolysis. Leaching of the dolomite ore in aqueous hydrochloric acid solution was investigated with respect to the effects of time on dissolution of the dolomite sample. The dependence of the observed dissolution rate on pH was est...

The uncatalyzed hydrolysis and removal of xylan from corn stover is markedly enhanced when operation is changed from batch to continuous flowthrough conditions, and the increase in hemicellulose removal with flow rate is inconsistent with predictions by widely used first-order kinetic models. Mass transfer or other physical effects could influence the hydrolysis rate, and two models reported in...

This paper presents an experimental study on the dissolution kinetics and solvent extraction of total gold from Ijero-ekiti (Nigeria) gold ore deposit by hydrochloric acid leaching followed by extraction with Tributylphosphate (TBP) in kerosene. The leaching investigation showed that the gold ore dissolution in HCl solution increases with increasing acid concentration, temperature and with decr...

Leaching of molybdenite concentrate with hydrogen peroxide in sulfuric acid solution was investigated to determine the effects of reaction time, reaction temperature, H2O2 concentration, H2SO4 concentration, pulp density and rotation speed on molybdenum extraction and molybdenite dissolution kinetics, using the Taguchi method. From analysis of var...