Synthesis and characterization of tenorite (CuO) nanoparticles from smelting furnace dust(SFD)

Tenorite (CuO) nanoparticles were prepared from a dilute CuSO4 solution. The solution was obtained by leaching (pH=1.5) of smelting furnace dust of Sarcheshmeh Copper Complex, Iran. The recovery of copper from the acidic sulphate solution was carried out by solvent extraction using Lix 984-N. Tenorite nanoparticles were synthesized by direct thermal decomposition of Langite [Cu4(OH)6SO4(H2O)2] as a precursor which was calcinated in air for 2 h at 750°C. The Samples were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The average diameter of the spherical pure CuO nanoparticles and their crystallite size were estimated to be 92 nm and 40nm, respectively. The simplicity of the present method suggests its potential application at industrial scale as a cheap and convenient way to produce pure CuO nanoparticles from dilute CuSO4 solutions obtained from leaching of smelting furnace dust

Template Free Synthesis of Hollow Ball-Like Nano-Fe2O3 and Its Application to the Detection of Dimethyl Methylphosphonate at Room Temperature

This paper is focused on the template-free synthesis of nanosized ferric oxide (nano-Fe2O3) and its application in quartz crystal microbalance (QCM) resonators to detect dimethyl methylphosphonate (DMMP), a simulant of Sarin. The X-ray diffraction (XRD) patterns confirm that the synthesized samples are made of Fe2O3 and the scanning electron microscopy (SEM) pictures show that the samples have ball-like shapes. The DMMP sensors with a sensing film of hollow ball-like and solid ball-like Fe2O3 are fabricated and their sensing characteristics are compared. The sensitivity of the hollow ball-like Fe2O3 sensor is more than 500% higher than the one of the solid ball-like Fe2O3 sensor. The hollow ball-like nano-Fe2O3 can be synthesized by a novel low temperature hydrothermal method. The sensors with the hollow ball-like Fe2O3 film perform well in a range of 1 to 6 ppm, with a sensitivity of 29 Hz/ppm at room temperature, while the appropriate recoverability and selectivity are maintained. In addition, the performance of different thicknesses of the sensing film of the hollow ball-like nano-Fe2O3 is investigated and the optimized relative film thickness of the hollow ball-like nano-Fe2O3 is found to be 20 μg/mm2

A novel technique to synthesis of tenorite (CuO) nanoparticles from low concentration CuSO4 solution

In this study CuO nanoparticles were prepared via direct thermal decomposition method using basic copper sulphates as wet chemically synthesized precursor which was calcined in air at 750°C for 2h. Samples were characterized by thermogravimetric (TG-DSC), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), infrared spectrum (IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD, EDS, and IR results indicated that the synthesized CuO particles were pure. The SEM and TEM results showed that the CuO nanoparticles were of approximate spherical shape, and 170±5 nm in size. Using this method, Cuo nanoparticles could be produced without using organic solvent, expensive raw materials, and complicated equipment

Geopolymerization of soil by sodium silicate as an approach to control wind erosion

Transportation of fugitive dust over long distances because of wind erosion is a severe environmental threat. Different approaches are experienced to control wind erosion, but durability and costs are the main drawbacks of existing techniques. This study hereby investigates sodium silicate usage as an alkaline additive to bind soil particles and control wind erosion. Sodium silicate is an environmentally safe material and the precipitated inorganic silica gel from which has the affinity with soil texture that makes the overall geopolymerization materials and method clean and environmentally friendly. The neutral condition of natural soils can reduce the alkalinity of sodium silicate’s alkalinity upon contact to the silica gel formation and soil geopolymerization. Different water-diluted solutions containing 50, 35, 20 wt% sodium silicate were prepared and sprayed over the soil surface while various specifications of the stabilized part were evaluated. It was found that interparticle cohesion, shear strength, and wind erosion were affected by sodium silicate content, as explained through a series of immersion, direct shear, and wind tunnel tests. A combination of mechanical and chemical forces can explain the interparticle cohesion since no chemical bonding was established between silica gel and soil particles, as described in Fourier-transform infrared spectroscopy analysis. Scanning electron microscopy coupled with energy-dispersive spectroscopy and thermogravimetric experiment displayed soil particles’ aggregation without mineralogical alteration. The achieved results implicate sodium silicate’s promising role as a stabilizer to bind the soil particles and control wind erosion

Comparison of different natural fiber treatments: a literature review

Interests in the use of natural fibers-fillers in composite materials are growing rapidly due to the low cost and high availability. However, poor surface adhesion and mineralization are the main drawbacks that restrict the use of natural fibers in different applications. Thus, it is essential to perform a treatment that can improve the surface properties of natural fibers before being used in the composites. Such treatments are physical (corona, plasma, etc.), chemical (alkaline, silane, acetylation, etc.), and biological (enzyme), but the benefits of each treatment considering energy consumption and effluent generation should be considered more in-depth. Via a literature review, this study investigated the mechanical performance, energy consumption, and generated effluents of chemical treatments (silane, alkaline, acetylation, and maleated coupling) as the consequence of fiber treatment to propose a more sustainable treatment at the scope of the treatment section in the factory of natural fibers-polymer composites (gate to gate). It was shown during this review study that the maleated coupling is a more sustainable method since it needs no specific energy during the treatment while produces no effluent and improves the mechanical strength performance of the composites more constantly

Influence of Hydrofluoric Acid Leaching and Roasting on Mineralogical Phase Transformation of Pyrite in Sulfidic Mine Tailings

Koohestani, Babak/0000-0002-1339-2563; YILMAZ, EROL/0000-0001-8332-8471WOS: 000551051500001Under the oxidative roasting process, pyrite, as a major mineral in sulfidic mine tailings, can transform to iron oxides. Generated iron oxides, if exhibiting enough magnetic properties, can be recovered via magnetic separation resulting in partial mine tailings valorization. However, due to the presence of various minerals and sintering possibility, it is advantageous to remove impurities and increase the pyrite content of mine tailings prior to the roasting procedure. in this case, hydrofluoric acid that has no influence on pyrite can be used to leach most inorganic minerals, including aluminosilicates. Therefore, this study investigated and compared the influence of the roasting process with and without hydrofluoric acid leaching pretreatment on mineralogical phase transformation of pyrite and magnetic properties of thermally generated minerals. Several tests and analyses were performed to study mineralogical phase transformation, morphology, elemental composition, surface characterization, and magnetic properties. Results of this study indicated that without acid leaching pretreatment, pyrite was mainly transformed to hematite. However, via acid leaching, fluorine, as a more electronegative element over oxygen, entered the compound and neglected the role of oxygen in thermal oxidation, instead reducing sulfur content of pyrite to only form pyrrhotite.Iran National Science Foundation (INSF)Iran National Science Foundation (INSF) [96016805]This research was financially supported by Iran National Science Foundation (INSF) with a research grant (NO:96016805, 2018)