The development, manufacturing and commercialization of nanomaterials require traceable characterisation processes for quality control and safety of both the exposed workers and final customers. Even if the production batches are considered to be compliant with the industrial applications intend...

The present investigation studied the recycling of zinc from brass ash which is a secondary product produced during the brass smelting process. A retiring cycle was devised to produce high-purity ZnO nanopowders. Recovery of > 90 wt% of the total zinc available was achieved after the calcination...

The pseudo-hollandite chromium sulfides, ACr5S8 (A=K, Rb, Cs) and A′0.5Cr5S8 (A′=Sr, Ba), have been synthesized and investigated in structural and magnetic properties. All the compounds crystallize in the isostructure with a monoclinic C2/m. Its crystal structure has triangular lattices and do...

Hexavalent chromium (Cr(VI)) is one of prevalent toxic and mobile heavy metal contaminants in the environment. In this study, synthetic iron sulfide nanoparticles (FeS NPs) stabilized with carboxymethyl cellulose (CMC) were applied to remediate Cr(VI) contaminated groundwater and saturated soil....

The present study, for the first time, reports the successful consolidation of chromium doped zinc sulfide (ZnS) polycrystalline infrared (IR) transparent ceramics (maximum transmittance of 67% at 11.6 μm) via hot pressing under vacuum. The phase composition of the as-sintered Cr2+:ZnS ceramics...

Hollow sulfides nanoparticles of MoS2, Cr2S3 and Mo0.9Cr0.1S2 (“inorganic fullerenes”) were prepared from SrMo(Cr)O4 precursors by means of a topotactic solid-gas reaction with H2S/CCl4 mixture. The obtained hollow sulfide nanoparticles have narrow size distributions and high specific surface ...

A highly sensitive and selective fluorescence sensor for detection of chromium(VI) and hydrogen sulfide was developed by using silicon nanoparticles (SiNPs) as probe. The fluorescence of SiNPs was effectively quenched by Cr(VI) via the inner filter effect. Upon addition of hydrogen sulfide, the ...

We showed previously that unsupported catalysts prepared from amine thiomolybdates incorporated with bivalent metals (Fe, Ni, Co) are highly active for hydrodenitrogenation (HDN) and hydrodesulfurization (HDS). In particular, an iron-promoted molybdenum sulfide catalyst gives a much higher HDN-t...

Sulfidation of nanoscale zerovalent iron (nZVI) has attracted increasing interest for improving the reactivity and selectivity of nZVI towards various contaminants, such as aqueous Cr(VI) removal. However, the benefits derived from sulfide modification that govern the removal of Cr(VI) remains u...

Hexavalent chromium (Cr(VI)) is an environmental concern due to the carcinogenic and mutagenic effect on living organisms. Sulfide minerals based Cr(VI) reduction is an economical and efficient strategy for Cr(VI) remediation. In this study, Cr(VI) reduction through the synergistic effect betwee...

Microbial extraction of nickel from lateritic chromite overburden (COB), Sukinda by Acidithiobacillus ferrooxidans has been investigated in this work. In anoxic environment, A. ferrooxidans reduced the ferric iron in goethite [Fe(O)OH] mineral of COB by using elemental sulphur as electron donor....

The platinum-group element ruthenium (Ru) is an important petrogenetic tracer of Earth’s accretion history, core-mantle interaction, mantle evolution and the exploration for magmatic sulfide deposits. However, its geochemical behavior in mafic-ultramafic systems is still not fully understood, w...

Aluminum spent potlining (SPL) was employed as both the fluxing agent and a source of carbonaceous reductant for the carbothermic reduction of chromite, aiming to allow effective separation of alloy from the slag component. The experimental results show that the carbonaceous component of the SPL...

The effect of surfactant polyoxyethylenesorbitan monolaurate (Tween-20) on the nickel bioleaching from pre-treated chromite overburden (COB), Sukinda with fungal strain Aspergillus niger, was examined in shake flasks. Along with the nickel recovery from COB by the fungal bioleaching, the effect ...

The nanocrystalline nickel chromite (NiCr2O4) with particle size of ∼20 nm was prepared by auto-combustion method. The nanocrystals were characterized by powder X-ray diffraction, vibrational spectroscopy and magnetic measurements. The expected structural phase transitions (cubic–tetragonal–o...

Chromite is a ubiquitous accessory mineral in the olivine-pyroxene cumulate bodies that host massive and disseminated nickel sulphide mineralization in intrusions of the Kabanga-Musongati-Kapalagulu Alignment in East Africa. Its composition is related to the conditions of emplacement and petrolo...

It is of interest to study the magneto-structural coupling in geometrically frustrated antiferromagnets, where structural distortion elevates the ground state degeneracy, leading to a long-range magnetic order. In this regard a cubic spinel compound of the form AB2O4 is currently drawing much at...

Pure nickel chromite (NiCr2O4) nanostructures were prepared via a new coprecipitation–calcination route by using [Ni(en)2(H2O)2](NO3)2 and [Cr(en)3]Cl3·3H2O as novel precursors. The as-prepared nickel chromite nanostructures were characterized by energy dispersive X-ray microanalysis (EDX), tr...

Considering the simplicity and flexibility of thermal treatment method for preparing fine nanocrystalline oxide, the present work reports up-scalable synthesis of nanosized nickel cobalt chromite spinel. The effect of calcination temperatures on the final properties of obtained materials was car...

The aim of the present work is to investigate the mechanism of growth of chromium silicides versus several parameters. The samples are constituted of a thin chromium layer (≈80 nm) which is deposited under vacuum by electron beam evaporation/condensation onto P+ implanted Si(1 0 0) and Si(1 1 1...