Metals play an important role in microbial metabolism by acting as cofactors for many enzymes. Supplementation of biological processes with metals may result in improved performance, but high metal concentrations are often toxic to microorganisms. In this work, methanogenic enrichment cultures growing on H2/CO2 or acetate were supplemented with trace concentrations of nickel (Ni) and cobalt (Co...

New selective coating materials are developed and used in advanced solar collector and absorber designs with improved efficiency. Cobalt and Copper sulfides nanoparticles are high interest for absorbers of solar thermal collectors due to their optical properties and high absorptance in the solar wavelength range (> 96%). In the present work, Cobalt and Copper sulfides nanoparticles were synthes...

The difference in the standard Gibbs free energy for the formation of any two oxides or sulfides is the chemical potential for selective reduction of metals from complex minerals. The magnitude of the Gibbs free energy difference is shown by plotting the univariant relationships for relevant sulfides and oxides. In this investigation, three examples of mineral sulfides are considered, and the e...

Acid bioleaching of a low-grade and polymetallic sulfide concentrate was studied, in order to determine suitable feed material particle size pH for efficient leaching valuable metals. The consisted pyrite (50 wt %), pyrrhotite (31 quartz (10 %) lower amounts cobalt, nickel, zinc copper (each <1 %). After adaptation microorganisms shake flasks, stirred tank tests were conducted at different l...

Agitation leaching is a promising technology in hydrometallurgy for treating copper–cobalt oxide ores. In this work, the behavior of ores containing around 2.3% Cu and 0.3% Co received from Congo was investigated varying particle size, acidity, pulp density, temperature, time, reduction potential. XRD, optical microscopy (OM), ICP-OES methods were used to examine chemical composition, morpholog...

Spent cobalt-based macroporous adsorbents are considered to be used for the hydrotreating process. Herein, spent materials from low-temperature desulfurization process were as organic sulfur catalysts. Physicochemical properties of waste characterized and performance COS conversion was evaluated at different conditions. The Co-containing exhibit considerable hydrogenation low temperature, resid...

Transparent nickel doped cobalt sulfide was fabricated on a SnO2:F electrode and tested as an efficient electrocatalyst and as an alternative to the expensive platinum counter electrode. In order to investigate how this electrode could affect the electrical characteristics of a dye-sensitized solar cell, we manufactured cells with the same TiO2 photoanode sensitized with dye (N719) and employin...

Due to the decreasing production of nickel and cobalt from sulfide sources, the Ni and Co extraction from the oxide ores (laterites) have become more prevalent. In this research work, the effects of calcination prior to leaching, acid concentration, percent solid, pH, and stirring speed on the nickel and cobalt recoveries from an iron-rich laterite ore sample were investigated using diffe...