Research into electro-hydraulic blasting impact on ore masses to intensify the heap leaching process

Investigative study into the hydrodynamics of heap leaching processes

Three mathematical models (mixed side-pore and profile side-pore diffusion with uniform or distributed pore length) are derived in dimensionless form to simulate the transport of solutes through the flowing channels and the stagnant pores of an unsaturated heap. Model parameters are determined from experimental tracer residence time distributions using the least square minimization approach. It...

the impact of portfolio assessment on iranian efl students essay writing: a process-oriented approach

this study was conducted to investigate the impact of portfolio assessment as a process-oriented assessment mechanism on iranian efl students’ english writing and its subskills of focus, elaboration, organization, conventions, and vocabulary. out of ninety juniors majoring in english literature and translation at the university of isfahan, sixty one of them who were at the same level of writing...

A Combined Chemical and Biological Heap Leaching of an Oxide Gold-bearing Ore

Fungal Leaching of Manganese Ore

Bioleaching is technologically feasible for extraction of manganese from low grade ores (containing manganese less than 35% by weight). The principle involves the non-enzymatic reduction of pyrolusite [Mn(IV) oxides] to +2 oxidation state by fungi with the production of metabolites such as oxalic acid and citric acid. In the present investigation, a fungal strain, Penicillium citrinum was isola...

Research on Variable Domain Electro - hydraulic Proportional Valve Control Technology

As the control system of the ship's crane is nonlinear , time-varying and large inertia, the traditional way to control is difficult to achieve control requirements. The text have the deck crane’ electro-hydraulic proportional valve as the research object, use the way of optimizing input’s fuzzy domain which called variable domain fuzzy PID, to solve the weakness of traditional control and brin...