Study on the Classification Performance of a Novel Wide-Neck Classifier.

A novelty-designed wide-neck classifier (WNC) was proposed to enhance the passing ability and classification efficiency of fine particles. Using computational fluid dynamics (CFD), we studied the flow field and velocity distribution in the newly designed WNC. The velocity of the fluid gradually decreased from the wall to the center and from the cylinder to the cone, which facilitates particle classification and thickening.

Potential Evaluation for Preparing Geopolymers from Quartz by Low-Alkali Activation.

Alkali fusion of granite sawdust at a high alkali dosage can significantly improve geopolymerization activity, but also result in a high alkali consumption and a poor geopolymer performance. In this work, quartz, the most inert component in granite sawdust, was selected to explore the effect of low-alkali activation on its reactivity and the compressive strength of geopolymer. It was found that the amount of activated quartz is mainly determined by the amount of alkali used for activation.

DFT Study on the Adsorption of Monomeric Hydroxyl Aluminum on Fe(II)/Mg Replacement Kaolinite (001) Surfaces.

In the natural environment, Al and Si in the kaolinite crystal structure are likely to form lattice defects or be replaced by low-valence positive ions so that the base surfaces have permanent negatively charged sites. It is therefore very important to investigate the adsorption process and adsorption mechanism of adsorbates on the replaced surfaces. In this paper, two types of surface models formed by replacing Al atoms in the alumina octahedron of kaolinite (001) surface with Fe(II) and Mg were selected as the adsorption surfaces, these being the kaolinite Fe(II)-(001) and Mg-(001) surfaces, respectively.

Multiphase Flow Characteristics in the Classification Process of a Novel Wide Neck Thickener: Experiment and Simulation.

A novel thickening equipment known as a wide neck thickener (WNT) was designed to solve the problem of depending only on gravity settlement of the thickener. The computational fluid dynamics method with the Reynolds stress and the volume of fluid models and the particle image velocimetry experimental method were both applied to investigate the pressure and velocity variation and turbulent characteristics of the WNT under different parameter settings. The results indicate that experiments and simulations are consistent.

Hierarchically porous biochar templated by in situ formed ZnO for rapid Pb and Cd adsorption in wastewater: Experiment and molecular dynamics study.

3D hierarchical porous biochar (HPBC) was synthesized by a thermally removable template without post-activation. Zn(NO) decomposition produced gases and ZnO in situ to activate and expand the three-dimensional micro-and mesopores. Compared with pristine biochar (BC), the specific surface area and pore volume of HPBC were increased by 223 and 75 times, respectively.

Salt coagulation or flocculation? In situ zeta potential study on ion correlation and slime coating with the presence of clay: A case of coal slurry aggregation.

The aggregation state of mineral slurry by coagulant with the presence of clay nanosheets appears similar to a flocculation gel with the absence of flocculant. The interactions between particles in mixed clay and quartz minerals systems are influenced by the interactions of ion correlation and slime coating, which creates zeta potential variation. Particle concentration has a substantial effect on zeta potential, and coal slurry has a relative high particle concentration.

Bifunctional polyaniline electroconductive hydrogels with applications in supercapacitor and wearable strain sensors.

In this article, bifunctional polyaniline/polyacrylamide (PANI/PAAm) hydrogel is fabricated. The hydrogel has capacitive performance and can be used for monitoring human motions. The effect of PANI doped with two different acids on the properties of hydrogels was researched.

Density Functional Theory Study of Water Molecule Adsorption on the α-Quartz (001) Surface with and without the Presence of Na, Mg, and Ca.

Adsorption of the single water molecule on the α-quartz (001) surface with and without the presence of Na, Mg and Ca was analyzed utilizing the density functional theory method. Our results demonstrate that the optimal adsorption configuration of the single water molecule on the α-quartz (001) surface lies in the bridge being configured with two formed hydrogen bonds. These were Os-Hw and Hs-Ow (s and w represent, respectively, surface and water molecules), while the main hydrogen bond is Hw-Os.

Study on the aggregation behavior of kaolinite particles in the presence of cationic, anionic and non-ionic surfactants.

Aggregation behaviors of kaolinite particles with different surfactants were studied in this paper. Aggregation settling yield and fractal dimension analysis were used to determine the aggregation results. Zeta potential measurements, adsorption tests, Infrared spectroscopy analysis and scanning electron microscope measurements were conducted for further investigation into the mechanism.

Hydrophobic aggregation of fine particles in high muddied coal slurry water.

The hydrophobic aggregation of fine particles in high muddied coal slurry water in the presence of four quaternary ammonium salts of 1231(dodecyl trimethyl ammonium chloride), 1431(tetradecyl trimethyl ammonium chloride), 1631(cetyl trimethyl ammonium chloride) and 1831(octadecyl trimethyl ammonium chloride) was investigated through the measurement of contact angles, zeta potentials, aggregation observation, adsorption and sedimentation. The results show that quaternary ammonium salts can enhance the hydrophobicity and reduce the electronegativity of particle surface, and thus induce a strong hydrophobic aggregation of slurry fine particles which promotes the settlement of coal slurry water. The adsorption of quaternary ammonium salts on slurry particles increases with the increase of alkyl chain length and reagent dosage, and will reach equilibrium when the dosage reaches a certain value.

Study of enhanced low-quality coal oxidative desulphurization and deashing by using HNO3 and microwave pretreatment.

In this paper, the effect of urea-hydrogen peroxide (UHP) solution on desulphurization and demineralization of coal with high sulphur and high ash by using HNO3 and microwave pretreatment was investigated. The oxidation process is strongly dependent on irradiation power and time for microwave pretreatment, UHP concentration, leaching time and temperature of the UHP solution. X-ray diffraction and Fourier transform infrared technique have been performed for the raw and treated coals.