At the industrial scale, bioleaching of metal sulfides includes two main technologies, tank leaching and heap leaching. Fluctuations in temperature caused by the exothermic reactions in a heap have a pronounced effect on the growth of microbes and composition of mixed microbial populations. Currently, little is known on the influence of pre-colonized mesophiles or moderate thermophiles on the a...

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...

The leaching concentration of copper ions from the industrial sludge that has been extracted using sulfuric acid may still exceed 15 mg/L, which is the leaching standard of the toxicity characteristic leaching procedure (TCLP) for hazardous waste in Taiwan. Therefore, the acid-extracted industrial sludge is still an important source of hazardous waste. Usually, hazardous waste in Taiwan must be...

Characterization of the leaching behavior of wastes is a crucial step in the environmental assessment for reuse or disposal scenarios. The release of inorganic contaminants from waste materials is typically evaluated by tank leaching of continuously water-saturated material. However, materials, in many field or management scenarios, experience cyclic wetting and drying under varied environmenta...

The tuff, a part of coal-bearing strata, in the Zhongliangshan coal mine, Chongqing, southwestern China, hosts a rare metal deposit enriched in rare earth elements (REE), Ga and Nb. However, the extraction techniques directly related to the recovery of rare metals in coal-bearing strata have been little-studied in the literature. The purpose of this paper is to investigate the extractability of...

Direct grazing of winter forage crops to feed non-lactating, pregnant dairy cows prior to calving is a common management practice in the New Zealand South Island. However, the high crop yields per hectare grazed, combined with a high stocking density of cows, means this potentially leads to large amounts of urinary nitrogen (N) deposited on bare, wet soil, that in turn, could lead to high nitra...

In this work, a hydrometallurgical process based on leaching is applied to recover cobalt and lithium from spent lithium ion batteries (LIBs). Citric acid and hydrogen peroxide are introduced as leaching reagents and the leaching of cobalt and lithium with a solution containing C(6)H(8)O(7) x H(2)O is investigated. When both C(6)H(8)O(7) x H(2)O and H(2)O(2) are used an effective recovery of Li...

In recent years, natural substances such as zeolite have been used to absorb heavy metals in soil in an attempt to decrease their availability to plants. Compared to other techniques, the use of zeolite is fast, clean, and inexpensive. This research was carried out to investigate the effects of an Iranian natural zeolite (clinoptilolite) on stabilizing Cd-contaminated soil treated with 0.01 M C...

C. Alister, M. Araya, and M. Kogan. 2011. Effects of physicochemical soil properties of five agricultural soils on herbicide soil adsorption and leaching. Cien. Inv. Agr. 38(2): 243-251. Once pesticides reach the soil, there are several factors that affect their soil behavior. To identify the principal soil and herbicide properties that control their adsorption and leaching, a study of five Chi...

In this paper, the leaching behavior of the major metals present in printed circuit boards waste is evaluated, aiming at its recycling by hydrometallurgy. Several leachants were compared (sulfuric, hydrochloric and nitric acids, at 2 M H concentration), at temperatures of 25oC and 90oC and 4 hours of reaction time. Sulfuric acid leaching was not very promising concerning metals dissolution bein...