kinetics of the chemical leaching of chalcocite from a low-grade copper ore in a ferric sulfate medium was investigated using the constrained least square optimization technique. the experiments were carried out for different particle sizes in both the reactor and column at constant eh, ph, and temperature. the leaching rate increased with increase in the temperature. about 50% of the cu recove...

the direct sulfation of three high purity iranian limestones and one precipitated calcium carbonate from different sources, containing more than 97 % caco3, were studied in a specially designed fixed bed reactor under atmospheric pressure, in the presence of excess co2 to prevent decomposition of caco3. experiments were carried out over a range of particle sizes from 1.6-2.5  mm at four tempera...

A shrinking core model is presented for the galvanostatic discharge of a metal hydride particle. A quantitative criterion for when the shrinking core can be completely neglected or approximated by a pseudosteady-state solution is presented. The effect of shrinking of the core on the discharge behavior of a metal hydride particle is also studied. © 2000 The Electrochemical Society. S0013-4651(00...

Unsatisfiable core analysis can boost the computation of optimum stable models for logic programs with weak constraints. However, current solvers employing unsatisfiable core analysis either run to completion, or provide no suboptimal stable models but the one resulting from the preliminary disjoint cores analysis. This drawback is circumvented here by introducing a progression based shrinking ...

Using the recently developed Cahn-Hilliard reaction (CHR) theory, we present a simple mathematical model of the transition from solid-solution radial diffusion to two-phase shrinking-core dynamics during ion intercalation in a spherical solid particle. This general approach extends previous Li-ion battery models, which either neglect phase separation or postulate a spherical shrinking-core phas...

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...

This paper constructs the probability model of the general multi-valued shrinking generator, which takes two-valued key stream shrinking generator and generalized shrinking generator as special cases. It discusses the probability properties of their output sequences, and gets the formulae of the coincidence of the output sequences with the original input sequences in particular. It also analyze...