FLOCCULATION OF FINE APATITE AIMED AT REDUCING ENVIRONMENTAL WATER USE PROBLEMS IN MINERAL PROCESSING PLANTS

2021 ◽  
Author(s):  
Alexandr Artemev
Keyword(s):  
High Efficiency ◽  
Solid Phase ◽  
Industrial Effluents ◽  
Environmental Water ◽  
Point Of View ◽  
Water Soluble ◽  
Acid Base ◽  
Tailing Dump ◽  
Apatite Concentrate ◽  
Circulating Water

"Water treatment technologies involving pre-treated industrial effluents without transporting them to the tailing dump are of interest primarily from an environmental point of view, as they reduce the environmental burden. The paper studies the possibility of purification of process waters from apatite concentrate production from suspended particles and water-soluble impurities using polyacrylamide flocculants. By studying the processes of adsorption of H+ and OH- ions from aqueous solutions, the acid-base properties of the surface of the solid phase of the most polluted technological product - the drain of the apatite concentrate thickener - the mineral composition of which is 90% apatite have been studied. The influence of the reagents present in the processing technology on the quantitative ratio of acid-base centres on the apatite surface has been evaluated. It has been shown that the interaction of these reagents with the mineral creates prerequisites for a greater efficiency of the anionic flocculant. The electro-surface properties of apatite treated with various reagents were studied using the laser Doppler electrophoresis method. The mechanism of fixation of ions present in the dispersion medium on the surface of apatite was studied by infrared spectroscopy. In order to determine the conditions under which various flocculants are in the most ionized state, studies were conducted on the change in the viscosity of the polyelectrolyte solution at different pH values. The position of the isoionic point for samples of cationic and anionic flocculants in the presence of reagents used in the apatite flotation and dehydration of apatite concentrate was studied. A research has been carried out on ""model"" and real suspensions in circulating water for a number of cationic, anionic and nonionic flocculants. The kinetic and concentration dependences of the flocculating capacity of the studied reagents were determined, which confirmed the high efficiency of the anionic type reagents"

scholarly journals The use of anionic flocculant in water treatment for flotation of apatite-nepheline ores

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 150-159
Author(s):  
A. V. Artemiev ◽  
G. V. Mitrofanova
Keyword(s):  
Solid Phase ◽  
Suspended Particles ◽  
Water Soluble ◽  
Iron Sulfate ◽  
Recycled Water ◽  
Acid Base ◽  
Efficient Operation ◽  
Apatite Concentrate ◽  
Wide Range ◽  
Adsorption Processes

Currently, an urgent problem is the improvement of methods for purification of industrial water from concentrates of suspended particles and water-soluble impurities using polyacrylamide flocculants. By studying the adsorption processes from aqueous solutions of H and OH ions, the acid-base properties of the surface of the solid phase of the most contaminated technological product have been analyzed, i. e. discharge of the thickener of apatite concentrate, the mineral composition of which is 90 % represented by apatite. The influence of reagents present in the processing technology (fatty acid collector, iron sulfate) on the quantitative ratio of acid-base centers on the surface of apatite has been evaluated. It has been shown that the interaction of these reagents with the mineral creates prerequisites for greater efficiency of the anion-type flocculant. In order to determine the conditions under which flocculants of different types are in the maximally ionized state, studies have been carried out to change the viscosity of the polyelectrolyte solution at different pH values. The position of the isionic point for samples of cationic and anionic flocculants in the presence of reagents used in apatite flotation and dehydration of apatite concentrate has been studied as well. Studies on model and real suspensions in recycled water for a wide range of cationic and anionic flocculants have been performed. Kinetic and concentration dependencies of flocculating capacity of analyzed reagents have been determined; the experiments have confirmed the more efficient operation of anionic-type reagents. The search for the most effective reagents will make it possible to provide optimal water values for the content of suspended particles and hardness cations when introducing closed water circulation technology.

scholarly journals Graphene oxide/β-cyclodextrin composite as fiber coating for high efficiency headspace solid phase microextraction of organophosphate ester flame retardants in environmental water

RSC Advances ◽  
2017 ◽  
Vol 7 (86) ◽  
pp. 54475-54484 ◽  
Author(s):  
Jiali Deng ◽  
Pengcheng Zhang ◽  
Tingting Jin ◽  
Hongbin Zhou ◽  
Jing Cheng
Keyword(s):  
Stainless Steel ◽  
Solid Phase Microextraction ◽  
Flame Retardants ◽  
High Efficiency ◽  
Steel Fiber ◽  
Solid Phase ◽  
Sol Gel ◽  
Environmental Water ◽  
Fiber Coating ◽  
Stainless Steel Fiber

The preparation of a GO/β-CD sol–gel stainless steel fiber coating and its application for HS-SPME of OPFR.

scholarly journals High-efficiency solid-phase microextraction performance of polypyrrole enhanced titania nanoparticles for sensitive determination of polar chlorophenols and triclosan in environmental water samples

RSC Advances ◽  
2021 ◽  
Vol 11 (46) ◽  
pp. 28632-28642
Author(s):  
Mingguang Ma ◽  
Yunxia Wei ◽  
Huijuan Wei ◽  
Xianyu Liu ◽  
Haixia Liu
Keyword(s):  
Solid Phase Microextraction ◽  
High Efficiency ◽  
Solid Phase ◽  
Environmental Water ◽  
Nanocomposite Coating ◽  
Titania Nanoparticles ◽  
Fiber Coating ◽  
Sensitive Determination ◽  
Direct Immersion

A PPy/TiO2 nanocomposite coating was fabricated by direct electropolymerization of pyrrole on annealed TiO2 nanoparticles and evaluated as a novel direct immersion solid phase microextraction fiber coating for the extraction of trace pollutants in water.

Application of Silica Nanoparticles in the Determination of Herbicides in Environmental Water Samples Using Liquid Chromatography-Mass Spectroscopy

2020 ◽  
Vol 16 (5) ◽  
pp. 748-756
Author(s):  
Mir Waqas Alam ◽  
Tentu Nageswara Rao ◽  
Yarasani Prashanthi ◽  
Vourse Sridhar ◽  
Adil Alshoaibi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Silica Nanoparticles ◽  
Solid Phase ◽  
Silica Nanoparticle ◽  
Environmental Water ◽  
Phase Extraction ◽  
Functionalized Nanoparticles ◽  
Supporting Material

Background: Herbicides are very beneficial in the crop yield with the aid of controlling weeds within the agriculture, but several herbicides are chronic in soil. Objective: In this study, nanoparticles and the packages of synthesized novel silica nanoparticles were studied for the preconcentration of herbicides. Methods: These nanoparticles prepared by the Stöber mechanism were purified and functionalized. Nanoparticles thus prepared successfully were used as supporting material for the preconcentration of residues of herbicides in the water. Results: Preconcentration was achieved by preparing the silica-based solid-phase-extraction cartridges. Nanoparticles used for this purpose were within the range of 50-250 nm. An SPE cartridge was prepared by packing 200 mg of silica nanoparticle in the empty cartridge of diameter 5.5 cm and length 0.6 cm in between PTFE frits. Aqueous solutions of 0.1 μg/ml of herbicides were prepared separately, and 10 ml of the solution was passed through the cartridge at the rate of 0.2 ml/min. After passing 10 ml volume of the aqueous solution, residues adsorbed on the cartridge were eluted using 2 ml of acetonitrile. The eluate was injected to determine the herbicide residue adsorbed on the SPE cartridge. Conclusion: In the study, it was found that greater than 90% of the herbicide residues were trapped on silica nanoparticle-based SPE cartridge. An analytical method was developed for the simultaneous determination of these herbicides. The residues were quantified by LC-MS/MS with ESI mode.

scholarly journals Polymer Binders of Ceramic Nanoparticles for Precision Casting of Nickel-Based Superalloys

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1714
Author(s):  
Paweł Wiśniewski
Keyword(s):  
Solid Phase ◽  
Average Particle Size ◽  
Water Soluble ◽  
Ethyl Silicate ◽  
Average Particle ◽  
Precision Casting ◽  
Polymer Binders ◽  
Initial Stage ◽  
Nano Alumina ◽  
Solid Phase Content

This study presents the general characteristics of binders used in precision casting of Nickel-based superalloys. Three groups of binders were described: resins, organic compounds, and materials containing nanoparticles in alcohol or aqueous systems. This study also includes literature reports on materials commonly used and those recently replaced by water-soluble binders, i.e., ethyl silicate (ES) and hydrolysed ethyl silicate (HES). The appearance of new and interesting solutions containing nano-alumina is described, as well as other solutions at the initial stage of scientific research, such as those containing biopolymers, biodegradable polycaprolactone (PCL), or modified starch. Special attention is paid to four binders containing nano-SiO2 intended for the first layers (Ludox AM, Ludox SK) and structural layers (EHT, Remasol) of shell moulds. Their morphology, viscosity, density, reactions, and electrokinetic potential were investigated. The binders were characterized by a high solid-phase content (>28%), viscosity, and density close to that of water (1–2 mPa·s) and good electrokinetic stability. The nanoparticles contained in the binders were approximately spherically shaped with an average particle size of 16–25 nm.

scholarly journals Multifunctional Cantilevers as Working Elements in Solid-State Cooling Devices

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 58
Author(s):  
Andraž Bradeško ◽  
Lovro Fulanović ◽  
Marko Vrabelj ◽  
Aleksander Matavž ◽  
Mojca Otoničar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Contact Resistance ◽  
High Efficiency ◽  
Thermal Contact ◽  
Point Of View ◽  
Practical Implementation ◽  
Cooling Devices ◽  
Cascade Structure ◽  
Lead Magnesium

Despite the challenges of practical implementation, electrocaloric (EC) cooling remains a promising technology because of its good scalability and high efficiency. Here, we investigate the feasibility of an EC cooling device that couples the EC and electromechanical (EM) responses of a highly functionally, efficient, lead magnesium niobate ceramic material. We fabricated multifunctional cantilevers from this material and characterized their electrical, EM and EC properties. Two active cantilevers were stacked in a cascade structure, forming a proof-of-concept device, which was then analyzed in detail. The cooling effect was lower than the EC effect of the material itself, mainly due to the poor solid-to-solid heat transfer. However, we show that the use of ethylene glycol in the thermal contact area can significantly reduce the contact resistance, thereby improving the heat transfer. Although this solution is most likely impractical from the design point of view, the results clearly show that in this and similar cooling devices, a non-destructive, surface-modification method, with the same effectiveness as that of ethylene glycol, will have to be developed to reduce the thermal contact resistance. We hope this study will motivate the further development of multifunctional cooling devices.

scholarly journals A Review on Coordination Properties of Al(III) and Fe(III) toward Natural Antioxidant Molecules: Experimental and Theoretical Insights

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2603
Author(s):  
Luana Malacaria ◽  
Giuseppina Anna Corrente ◽  
Amerigo Beneduci ◽  
Emilia Furia ◽  
Tiziana Marino ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Natural Antioxidants ◽  
Point Of View ◽  
Water Soluble ◽  
Natural Antioxidant ◽  
Theoretical Point ◽  
Structure And Properties ◽  
Coordination Properties ◽  
Soluble Molecule ◽  
Living Organisms

This review focuses on the ability of some natural antioxidant molecules (i.e., hydroxycinnamic acids, coumarin-3-carboxylic acid, quercetin, luteolin and curcumin) to form Al(III)- and Fe(III)-complexes with the aim of evaluating the coordination properties from a combined experimental and theoretical point of view. Despite the contributions of previous studies on the chemical properties and biological activity of these metal complexes involving such natural antioxidants, further detailed relationships between the structure and properties are still required. In this context, the investigation on the coordination properties of Al(III) and Fe(III) toward these natural antioxidant molecules might deserve high interest to design water soluble molecule-based metal carriers that can improve the metal’s intake and/or its removal in living organisms.

An uncoordinatedly tertiary nitrogen based tricarboxylate Calcium network with Lewis acid-base dual catalytic sites for cyanosilylation of aldehydes

2020 ◽  
Author(s):  
Xian-Ming Zhang ◽  
Ying-Xia Wang ◽  
Hui-Min Wang ◽  
Pan Meng ◽  
Dong-Xia Song ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Efficient Method ◽  
High Efficiency ◽  
Acid Base ◽  
Catalytic Sites ◽  
Tertiary Nitrogen

The design and utilization of dual sites for synergistic catalysts has been recognised as an efficient method towards high-efficiency catalysis in the cyanosilylation of aldehydes, which gives the key intermediates...

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