An electrode system to study the mechanism of fine microgram powder sulfide mineral dissolution was developed by using a relatively simple method that enables the attachment of micrograms of fine powder to a platinum plate surface. This system yields highly reproducible results and is sensitive compared with conventional electrode systems for various sulfide minerals such as pyrite, chalcopyrit...

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...

Iron-oxidizing thiobacilli were adapted to grow on a chalcopyrite and a galena ore concentrate. When grown on the chalcopyrite concentrate, the bacteria exhibited a doubling time of 38.4 +/- 2.9 h, with a final cellular protein concentration of 185 mug/ml and solubilization of 10.3 g of copper per liter. When grown on the galena ore concentrate, the generation time was 39.6 +/- 2.7 h, with a fi...

Tertiary low sulfidation (LS) epithermal deposits in the western USA often show evidence of the former presence of nanoparticle-sized precious-metal and silica phases in the highest grade (bonanza) ores. Here, nanoparticles are defined to have a size less than ~10 m. The ore-mineral textures that formed from aggregation of nanoparticles (or colloids) observed to date in these ores include elect...

Bacterial contact leaching of ores is more effective than non-contact leaching. Adhesion is the first step for leaching bacteria to form a biofilm on a mineral surface. Extracellular polymeric substances (EPS) are pivotal for mediating bacterial adhesion to a substratum. In order to clarify the role of EPS, we measured the adhesion forces between chalcopyrite-, sulfuror FeSO4·7H2O-grown cells o...

We have studied the structural and electronic properties of pure, deffect and doped chalcopyrite semiconductors using Density functional theory (DFT) based first principle technique within Tight binding Linear Muffin Tin orbital (TB-LMTO) method. Our calculated structural parameters such as lattice constant, anion displacement parameter(u) in case of pure chalcopyrite and anion displacement par...

In this work, we present frozen phonon and linear response ab-initio research into the vibrational properties of the CuGaS2 chalcopyrite and transition metal substituted (CuGaS2)M alloys. These systems are potential candidates for developing a novel solar-cell material with enhanced optoelectronic properties based in the implementation of the intermediate-band concept. We have previously carrie...

A non-vacuum, two-step process has been used to prepare a series of nanocrystalline CuIn1−xGaxSe2 (x = 0, 0.25, 0.5, 0.75, 1) materials. An open-air solvothermal preparation in triethylenetetramine solvent was followed by annealing at 500 °C in a nitrogen atmosphere for 20 min. All materials have mixed clustered plate, spherical particle, and nanorod morphologies with the smallest particle diam...

Thiobacillus ferrooxidans cells grown on sulfur, pyrite, and chalcopyrite exhibit greater hydrophobicity than ferrous ion-grown cells. The isoelectric points of sulfur-, pyrite-, and chalcopyrite-grown cells were observed to be at a pH higher than that for ferrous ion-grown cells. Microbe-mineral interactions result in change in the surface chemistry of the organism as well as that of the miner...