Leaching kinetics of gibbsitic bauxite with sodium hydroxide
نویسنده
چکیده
In this paper the results of a leaching kinetics study of bauxite ore with sodium hydroxide are presented. The effect of ore particle size, sodium hydroxide concentration and reaction temperature on the Al2O3 extraction rate was determined. The results obtained showed that 99% of Al2O3 was leached out using -200+270 mesh ore particle size at a reaction temperature of 105 °C for 60 min reaction time with 250 g/L NaOH. The solid-to-liquid ratio was maintained constant at 1:20. The results indicated that leaching of bauxite is the rate controlling process. The activation energy was determined to be 46.04 kJ/mole, which was characteristic for a chemically controlled process.
منابع مشابه
Leaching Kinetics of Stibnite in Sodium Hydroxide
Spherical pellets of antimony sulphide were dissolved in 1 molar sodium hydroxide solutions at different temperatures. It was found that the shrinking core with ash layer model could satisfactorily explain the dissolution process. Using this model it was found that initially the rate controlling step is a chemical reaction with activation energy of 10.2 kJ/mol. As the ash layer builds up, diffu...
متن کاملBayer's Process for Alumina Production: a Historical Perspective
The Bayer Process (for alumina) as we know it today involves two steps: • The pressure leaching of bauxite with NaOH solution to obtain sodium aluminate solution. • The precipitation of pure aluminum hydroxide from this solution by seeding with fine crystals of Al(OH)3 . The leaching step was invented five years after the precipitation step (Table 1), and the precipitation step was an improveme...
متن کاملRecovery of Vanadium from Esfahan Steel Company Steel Slag; Optimizing of Roasting and Leaching Parameters
In this Study, vanadium recovery from the steelmaking converter slag was studied. Salt roasting-basic leaching is the process which was applied to separate and extract vanadium from steel making slag. Ground slag was roasted after mixing with determined quantities of sodium carbonate. The effect of time and temperature of roasting and sodium carbonate content were studied. The optimum temperatu...
متن کاملLeaching of Bauxite Residue with Mineral Acids
Aiming at the industrial scale development of a Scandium (Sc)-selective leaching process 14 of Bauxite Residue (BR), a sufficiently numerous set of process design aspects has been 15 investigated, by appropriate exploitation of available experimental data. The interpretation of 16 experimental data for Sc leaching yield, with sulfuric acid as the leaching solvent, has shown 17 significant impac...
متن کاملKinetics of Sphalerite Leaching by Sodium Nitrate in Sulfuric Acid
In the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. The effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid (S/L) ratio were analyzed. The dissolution rate increased with increase in the sulfuric acid an...
متن کامل