This study investigated the removal of sulfur and iron from shungite rocks through different methods after fine grinding: flotation, magnetic separation, microwave treatment, chemical leaching. In this work, first, a mineralogical was conducted. The carbon, silica, iron, compositions in as-received were 45.4%, 38.3%, 4.6%, 2.4%, respectively. grade 1.4% obtained. wet high-gradient separation at...

An acidophilic, sulfur-oxidizing Acidithiobacillus thiooxidans MET bacterium was isolated from anaerobically digested, dewatered sewage sludge. This bacterium showed sulfur-oxidizing ability at both acidic and neutral conditions, and allowed metal leaching even at a high (130 g L(-1)) sludge solids concentration. We found that low metal leaching efficiency at high solids concentration was mainl...

In our study we showed the importance of holistic approach to evaluation of chemical stabilization using phosphate amendments, where all aspects of chemical treatments were observed. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil from the former zinc smelter area in the Celje re...

Copper-based compounds are some of the most important biocides for the protection of wood in heavy duty applications. In the past, copper was combined with chromium compounds to reduce copper leaching, but a recent generation of copper-based preservatives uses ethanolamine as a fixative. To elucidate the leaching of copper biocides from wood, Norway spruce (Picea abies) wood was treated with a ...

The classical method of melting lead by fire-assay (Pb-FA) is the most frequently used analytical technique in gold prospection. The crucible solid waste which is generated in this process is usually characterized by chemical and mineralogical composition, granulometric size distribution, and classified according to Brazilian Environmental Regulations. This study demonstrates how acid leaching ...

In spite of the environmental and commercial interests in the bacterial leaching of pyrite, two central questions have not been answered after more than 35 years of research: does Thiobacillus ferrooxidans enhance the rate of leaching above that achieved by ferric sulfate solutions under the same conditions, and if so, how do the bacteria affect such an enhancement? Experimental conditions of p...

To investigate the pollution characteristics of Pb and Cd in mining soil, dynamic leaching tests was conducted to explore characteristics. Pollution evaluated using Risk Index (RI) Assessment Code (RAC). The results showed that under simulated acid rain, soil had a certain buffer capacity, pH value solution varied between 5.0 8.5. Heavy metals release also varied, with highest amount dissolved ...

The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 10 N/L) at 85 ̊C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), ...

Calcified roasting followed by dilute sulfuric acid leaching is a promising process for cleaner vanadium extraction from converter slag. However, some impurities, like Ca, Mg, Mn, Si and Al, also transfer into the solution, accompanying V during leaching, leading to product of pentoxide prepared this acidic vanadium-bearing inferior traditional sodium water leaching. A chemical precipitation me...

The recovery of precious metals from waste printed circuit boards (PCBs) is an effective recycling process. This paper presents a promising hydrometallurgical process to recover precious metals from waste PCBs. To simplify the metal leaching process, large pieces of PCBs were used instead of a pulverized sample. The chemical coating present on the PCBs was removed by sodium hydroxide (NaOH) tre...