The influence of microwave heating on the leaching kinetics of chalcopyrite and sphalerite has been investigated. Chalcopyrite is inert to many leaching agents, especially ferric ion media. This mineral is considered to be one of the largest sources of copper, in terms of the scale of availability, and copper is usually extracted by pyrometallurgical processes. However, there has recently been ...

titanium dioxide is widely used in the manufacturing of paints, varnishes, lacquer, paper, paperboard, printing inks, rubber, floor covering, and ceramics and so on. white titanium dioxide pigment has been produced by two main processes. the sulfate and the chloride processes. each of these two routes requires different feedstocks. however, economic and environmental pressures are shifting the ...

Background: Laboratory leaching tests on treated wood were performed during a European robustness study in the framework of the validation of a tank leaching test procedure that has been proposed for construction products in order to determine the potential release of dangerous substances which can be transferred to soil and groundwater. The release of substances has to be determined also for m...

salinization is the main characteristic of soils in arid and semi-arid regions which reduce the agricultural potential ofirrigated lands. therefore, soil reclamation as well as determination of the leaching requirement for salt control is veryimportant for better plant growth. in this study, the effects of leaching on saline soils of sistan region, southeast of iranwere examined using unsaturat...

The rapid growth in the use of electronic equipments, combined with early obsolescence has contributed enormously to the generation of large quantity of electronic (e) waste. One such e-waste, the mobile phone printed circuit boards (PCBs) contain various precious metals which can be extracted by different hydrometallurgical routes. The present work deals with the recovery of gold using ammoniu...

Leaching studies of a sludge produced by the physico-chemical treatment of wastewaters generated by a Ni/Cr plating plant were carried out in both sulphuric acid and ammoniacal media aiming to decide which of them would be the best treatment for this kind of waste material. The dissolution behaviour of some metals (Cu, Ni, Cr and Zn) was studied in order to assure the best metal recovery condit...

Extracting AlCl3·6H2O from acid leaching solution through crystallization is one of the key processes to extracting aluminum from fly ash, coal gangue and other industrial solid wastes. However, the obtained products usually have low purity and a key problem is the lack of accurate data for phase equilibrium. This paper presented the non-equilibrium phase diagrams of AlCl3-NaCl-H2O (HCl) salt-w...

The influence of pH on the leaching behaviour of air pollution control (APC) residues produced in municipal solid waste incineration (MSWI) is addressed in this study. The residue is considered hazardous waste, and in accordance with their chemical properties, the leaching of contaminants into the environment is the main concern. Several leaching tests can be used for research studies or regula...

Upon rewetting, lichens lose polyols through leaching. We quantified leaching losses for 21 species under simulated rainfall. Polyol concentrations in these lichens range from 1.0 to 8.8%, with a mean of 2.8%. Leaching losses range up to about 7.5 mg (polyol)/g (lichen dry weight) in a typical rain event. The rate of polyol leaching declines exponentially, becoming negligible within 1 hour of c...

Interest for application of hydrometallurgical processes in a processing of complex sulphide ores and concentrates has increased in recent years. Their application provides better metal recoveries and reduced emission of gaseous and toxic ageneses in the environment. The kinetics and mechanism of sphalerite leaching from complex sulphide concentrate with sulphuric acid and sodium nitrate soluti...