Although bioleaching was used unknowingly by the ancients to extract metals (principally copper) from ores, the development of modern commercial bioleaching processes is relatively new. It began in the late 1940s, with the discovery of the role of bacteria in the formation of acid mine drainage. From there, research and development activities in the field flourished, and the earliest commercial...

Leaching occurs in metals recovery, in contaminated soil washing, and in many natural processes, such as fertilizer dissolution and rock weathering. This paper presents a model developed to simulate the transient evolution of the dissolved chemical species in the heap and column isothermal leaching processes. In this model, the solid bed is numerically divided into plane layers; the recovery of...

A method in combination of acid leaching, chemical exchange and ferrite process was applied to recycle copper and confer higher chemical stability to the sludge generated from etching process in printed circuit board industry. Ninety-five percent copper could be recycled in the form of powder from the sludge. Moreover, not only the wastewater after chemical exchange can be treated to fulfill th...

Leaching of calcium ions increases the porosity of cement-based materials, consequently resulting in a negative effect on durability since it provides an entry for aggressive harmful ions, causing reinforcing steel corrosion. This study investigates the effects of leaching behavior of calcium ions on the compression and durability of cement-based materials. Since the parameters influencing the ...

In the present study, the feasibility to use phosphate solubilizing bacteria (PSB) to develop a biological leaching process of rare earth elements (REE) from monazite-bearing ore was determined. To predict the REE leaching capacity of bacteria, the phosphate solubilizing abilities of 10 species of PSB were determined by halo zone formation on Reyes minimal agar media supplemented with bromo cre...

This paper provides an overview of hydrometallurgical copper extraction studies in which liquid technology has been used with four deposits different compositions. The sulfuric acid consumption rate and efficiency, are dependent on the initial content forms calcium compounds other impurities ore samples, were calculated, results presented herein. It was established that during leaching process,...

For the past 60 yr, chromate-copper-arsenate (CCA) has been used to pressure-treat millions of cubic meters of wood in the United States for the construction of many outdoor structures. Leaching of arsenic from these structures is a possible health concern as there exists the potential for soil and groundwater contamination. While previous studies have focused on total arsenic concentrations le...

Metals are a finite resource that necessary to maintain living standards in modern society, due their countless applications, such as transportation vehicles, building and construction, household appliances, electronic devices, etc. [...]