The removal of heavy metal from sludge before disposal or application to farmland is a necessary step to achieve a more safe sludge usage or disposal. Chemical extraction using inorganic acids (nitric, hydrochloric) and organic acids (citric, oxalic) were tested for extraction of chromium, copper, nickel, lead and zinc from contaminated sewage sludge at different pH and reaction time. Results r...

Heap leaching accounts for a fifth of global copper production, sourced primarily from porphyry ores, yet metal recoveries are often not optimal. Gangue, and its interaction with acid, plays an important role in such processes. Thus, a proper understanding of gangue minerals present in the ore, their textural relationships relative to particle size distribution, reactivity with acid under diffe...

For the dehydration process of biomass alcohol using a zeolite NaA (LTA) membrane supported by an alumina porous support tube, it is very important to understand damage of the surface crystal, which may be caused by acetic acid. Therefore, the surface structure and the chemical composition of the LTA membrane that reacted with water or acetic acid (pH 3-4) were investigated by the Fourier Trans...

Precious metals are the most attractive resources in waste printed circuit boards (PCBs) of mobile phones. In this work, an alternative process for recovering Au, Ag, and Pd from waste PCBs of mobile phones by supercritical water oxidation (SCWO) pre-treatment combined with iodine-iodide leaching process was developed. In the process, the waste PCBs of mobile phones were pre-treated in supercri...

according to the unique properties and many applications of nano gold powder, it was prepared from an acid leaching tail solution. the low value residual gold ions existed in acid leaching tail solution in mouteh gold mine in iran with fellow heavy metals as pollutants (fe2+, cu2+, and zn2+). preparation of nano gold particles is achieved by two steps: first, by addition of ammonia as separatio...

in this paper, leaching of lead and cadmium was investigated from porcelain over glaze designs between different colors.  also the effect of microwave heating was considered on leaching of lead and cadmium.  dishes were selected with a decor with the dominant color of gray, red, yellow, blue, and dark blue. amounts of cadmium and lead which leached from the container by acetic acid and orange j...

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...