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...

research topics dealing with the application of the markal model have been quite common in the last 20+ years. every new paper has added new insight into the potential of using such a model for a variety of purposes. not only global but also local applications have shown both limits and benefits when dealing with manifold energy-environmental-resources optimal management. the aim of this wo...

A physical-space version of the stretched-vortex subgrid-stress model is presented and applied to large-eddy simulations of incompressible flows. This version estimates the subgrid-kinetic energy required for evaluation of the subgrid-stress tensor using local second-order structure-function information of the resolved velocity field at separations of order the local cell size. A relation betwe...

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...