In this paper, gold leaching of a refractory sulfide concentrate by chloride–hypochlorite solution was investigated and effects of stirring speed, temperature and particle size on the leaching rate were reported. Experimental data for leaching rate of gold were analyzed with the shrinking–core model. Results were consistent with chemical reaction control mechanism in the first 1 h of leachin...

Accurate descriptions of P leaching are important because excess P applied to soils can enter surface water via leaching and subsurface transport, thereby negatively impacting water quality. The objectives of this study were to monitor P leaching in soils with a long-term history of waste application, relate soil solution P concentrations to soil P status, and quantify P leaching losses. Soil s...

in this work, we developed a method which combined the processes of acid-leaching, ammonium jarosite precipitating and electro-depositing to recover copper and nickel from electroplating sludge. residual sludge from an electroplating plant located in qingdao was used for acid-leaching, and more than 95% of copper, nickel, zinc, chromium and iron were extracted from the sludge. after acid-leachi...

However, the conventional gold recovery process is cyanidation, due to the recent environmental laws; researchers are looking for alternative methods for the recovery of gold. Furthermore, the copper anode slime is one of the most important secondary sources of gold (about 1200 ppm). So, the main objective of the current work is gold separation from copper anode slime as a rich secondary source...

The use of Thiobacillus ferrooxidans bacteria in the process of copper and iron leaching from chalcopyrite coming from Kotlina Ktodzka was investigated. The influence of the mineral content in the leaching solution the pH value and refinement of chalcopyrite on the subsequent stages of leaching was established. The process was described by the 1st order reaction inhibited by one of the products...

Bacterial leaching of an As-containing pyrite concentrate produced acidic (pH < 1) leachates. During the leaching, the bacteria solubilized both As and Fe, and these two elements were distributed in solution-phase and solid-phase products. Jarosite and scorodite were the exclusive crystalline products in precipitate samples from the bacterial leaching of the sulfide concentrate.

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...

Overland flow from cropland areas often contains nutrients and residue materials can either contribute to runoff nutrient load through leaching or remove nutrients by sorption. Measurements were made of leaching and sorption of nitrogen and phosphorus from corn (Zea mays L.), soybean (Glycine max (L.) Merr.) and winter wheat (Triticum aestivum L. cv. Pastiche) residues placed in solutions conta...

Leaching mechanism of zinc oxide is important not only to understand zinc smelting process but also to develop of new zinc recycling process. Recycling of zinc is mainly done by treatment of electric arc furnace dust (EAF dust). In Japan pyro metallurgical process is enhanced for EAF dust treatment, however only zinc oxide can be recovered by pyro metallurgical process. Hydro metallurgical proc...

in present investigation the biological leaching of aluminum by isolated fungi from red mud, the main waste product of the alkaline extraction of al from bauxite was studied. biological leaching experiments were carried out using indigenous, date and orange specimen fungi, aspergillus niger, penicillium simplicissimum notatum. savored dextrose chloramphenicol agar (sda) was used as medium for t...