scholarly journals Talc Flotation—An Overview

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 662
Author(s):  
July Ann Bazar ◽  
Milad Rahimi ◽  
Siavash Fathinia ◽  
Mohammad Jafari ◽  
Vitalis Chipakwe ◽  
...  
Keyword(s):  
Contact Angles ◽  
Selective Separation ◽  
Separation Performance ◽  
Gangue Mineral ◽  
Thermal Treatments ◽  
High Chemical ◽  
Factors Affecting ◽  
Wide Ph Range ◽  
Ph Range ◽  
High Chemical Stability

Talc is a naturally hydrophobic gangue mineral in most sulfide ores. However, talc has vast applications in the cosmetics, paper, and paint industries due to its high chemical stability, and its demand continues to grow. Since flotation is the most effective beneficiation technique for upgrading sulfides, the high hydrophobicity of talc has made its selective separation challenging. This paper explored the different properties of talc and the different factors that affect its flotation separation performance as a proven versatile beneficiation technique. Surface properties, zeta potential measurements, contact angles, and other factors affecting the talc flotation efficiency were discussed in detail. It was observed that the surface face/edge ratio (particle size) has a direct relationship with the level of talc hydrophobicity. Talc surfaces are negatively charged in a wide pH range (pH 2–12). Different depressants have already been studied; however, most of them showed low selectivity. The addition of ions such as Ca2+ could enhance talc depression. Pretreatment methods such as ultrasonic and thermal treatments were reported to decrease the talc floatability. It was demonstrated that the development of new selective depressants or pretreatment options for talc flotation requires attention in future investigations to improve its selective separation.

Porous Ceramics for High Temperature Filters

2008 ◽  
Vol 47-50 ◽  
pp. 960-963
Author(s):  
Cristina Ghitulica ◽  
Ecaterina Andronescu ◽  
O. Nicola ◽  
Mihaela Birsan
Keyword(s):  
Ceramic Powder ◽  
Mineralogical Composition ◽  
Porous Ceramics ◽  
Precipitation Method ◽  
Mechanical Resistance ◽  
Thermal Treatments ◽  
High Chemical ◽  
Low Thermal Expansion ◽  
Co Precipitation ◽  
High Chemical Stability

Cordierite based ceramic porous materials are very promising for filtering applications, due to their low thermal expansion coefficient, but also due to high chemical stability and good mechanical resistance. The cordierite powders were obtained through the co-precipitation method, while the porous ceramics were prepared by mixing the ceramic powder with an organic compound, which will burn during consequent thermal treatments, leading to an open pore ceramic web. Samples with different proportions of glucose were thermally treated at temperatures between 1050 and 1400oC. The samples were analyzed in what it concerns the mineralogical composition, open porosity and pores distribution, compressive strength and microstructure.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

High degradation efficiency of sulfamethazine with the dual-reaction-center Fe-Mn-SiO2 Fenton-like nanocatalyst in a wide pH range

2021 ◽  
Author(s):  
Manoj Kumar Panjwani ◽  
Qing Wang ◽  
Yueming Ma ◽  
Yuxuan Lin ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Center ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Wide Ph Range ◽  
Ph Range

The development of a heterogeneous Fenton-like catalyst, possessing high degradation efficiency in a wide pH range, is crucial for wastewater treatment. The Fe-Mn-SiO2 catalyst was designed, and prepared by a...

Multilevel/hierarchical nanocomposite imprinted regenerated cellulose membranes for high-efficiency separation: A selective recognition method with Au/PDA-loaded surface

2021 ◽  
Author(s):  
Ming Yan ◽  
Yilin Wu ◽  
Rongxin Lin ◽  
Faguang Ma ◽  
Zhongyi Jiang
Keyword(s):  
Molecular Imprinting ◽  
High Efficiency ◽  
Selective Separation ◽  
Selective Recognition ◽  
Regenerated Cellulose ◽  
Separation Performance ◽  
Recognition Method ◽  
Membrane Materials ◽  
Loaded Surface ◽  
Cellulose Membranes

Although many researchers have done lots of studies on improving the selective separation performance of membrane materials, conceptions and applications of membrane-based molecular imprinting separation&recognition with both high permselectivity and...

scholarly journals Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Reduced Graphene ◽  
Heterogeneous Interfaces ◽  
Wide Ph Range ◽  
Ph Range ◽  
A Current ◽  
Poor Stability

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

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