Leaching kinetics

The rate of dissolution is limited by oxygen availabiUty rather than by cyanide concentration. When oxygen solubiUty is reduced by water salinity or by consumption by ore constituents such as sulfide minerals, enrichment of the air with oxygen or addition of hydrogen or calcium peroxide improves leaching kinetics and decreases cyanide consumption (10). 

Baur, J. P. Gibbs, H. L. Wadsworth, M. E., Initial-Stage Sulfuric Acid Leaching Kinetics of Chalcopyrite Using Radiochemical Techniques, 1974, United States Bureau of Mines Report of Investigations 7823, Washington, D.C. 

Phase II examined the leaching characteristics of C R materials, full development of a predictive model, and the validation of the overall evaluation methodology. Validation of the methodology was achieved by evaluating a number of C R materials and by broadening the evaluation criteria to include leaching kinetics, reference environments, and impact interpretation. 

The following sections represent the different solid phases used to study the leaching kinetics and sorption processes of different SWM leachates. 

Rate Constants for Biphasic Chemical Reaction and Leaching Kinetic Models at 180°C... 

Guo, H., Deschenes, G., Pratt, A., Fulton, M. Lastra, R. (2005). Leaching kinetics and mechanisms of surface reaction during cyanidation of gold in the presence of pyrite and stibnite. Minerals and Metallurgical Processing, 22(2), 89-95. 

Mechanism Leaching may simply result from the solubility of a substance in a liquid, or it may be enabled by a chemical reaction. The rate of transport of solvent into the mass to be leached, or of the soluble fraction into the solvent, or of extract solution out of the insoluble material, or of some combination of these rates may influence overall leaching kinetics, as may an interfacial resistance or a chemical reaction rate. 

Investigation of leaching kinetics complementary method to access the... 

Similar to FI systems, in-line coupling of a sequential injection network with suitable detectors renders a detailed insight into leaching kinetics. As a consequence of the discontinuous flow nature of SIA, the in-line hyphenation of microcolumn assays with ETAAS is relatively simple, because of the discrete, noncontinuous operation of the detector. On the other hand, interfacing the miniaturized flow assembly with continuously operating detectors such as FAAS, HG-AFS, ICP-AES and ICP-MS requires the incorporation of conventional sample injectors (e.g., solenoid valves, rotary valves) for discrete introduction into the detection instrument of metered leachate volumes. 

Jimoh, M., Frenzel, W., Muller, V.. Stephanowitz, H.. and Hoffmann. E. (2004). Development of a hyphenated microanalytical system for the investigation of leaching kinetics ofheavy metals in environmental samples. Anal. Chem. 76. 1197-1203. 

The ireaimerit presented here relates to the leaching kinetics of an ore fragment with its army of minerals. For porposes of clarity, the ore fragment is referred to as a matrix black. In this section the treatment includes primarily Ihe kinetics of single matrix-block reactions exclusive of bulk flow parameters. 

It is reasonable to assume two limiting cases of leaching kinetics, dissolution of the waste form and diffusion of radioactive species from the waste form, representing upper and lower limits of the fraction leached within a given time period. The corresponding types of equation are (F = fractional release)... 

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