scholarly journals Application of Colloids and Its Relevance in Mineral Engineering

2021 ◽  
Author(s):  
Abhyarthana Pattanaik ◽  
Rayasam Venugopal
Keyword(s):  
Chemical Engineering ◽  
Colloidal Stability ◽  
Froth Flotation ◽  
Particle Surface ◽  
Mineral Processing ◽  
Process Conditions ◽  
Lower Grade ◽  
Chemical Reagents ◽  
Colloidal Chemistry ◽  
To Come

Mineral engineering is an interdisciplinary branch which includes many branches like physics, chemistry, math and sub branches like instrumentation, chemical engineering, mechanical engineering, geology etc. Amongst the various separation/beneficiation techniques of mineral processing, froth flotation is one of the most important fines beneficiation technique, which depends upon the surface and colloid chemical phenomena as the basis of selectivity. The method of separation relies on the surface state and colloidal chemistry of the ore particles and chemical reagents. Adsorption at the mineral solution interface is of major importance for the behaviour of mineral particles in the solution and for successful flotation performance. Adsorption of simple ions determine the change of the particle surface and electrochemical properties of the pulp/slurry phase and therefore affect the colloidal stability and the adsorption behaviour of reagent on the mineral surface. This chapter describes in detail about the role, importance and application of colloidal chemistry in mineral processing especially froth flotation. Froth flotation will remain a key unit operation for the treatment of low-grade ore fines for the decades to come with the overarching challenge as the need of the hour is to modify and improve existing process conditions so as to maintain an acceptable grade and recovery response for the feed whose liberation is more finer, more complex association of minerals and of lower grade.

Concept of Seafloor Mineral Processing for Development of Seafloor Massive Sulfides

2011 ◽  
Author(s):  
Yasuharu Nakajima ◽  
Shotaro Uto ◽  
Shigeo Kanada ◽  
Joji Yamamoto ◽  
Ichihiko Takahashi ◽  
...  
Keyword(s):  
High Pressures ◽  
Pure Water ◽  
Analytical Data ◽  
Mineral Resources ◽  
Mineral Processing ◽  
Column Flotation ◽  
Metallic Elements ◽  
Massive Sulfides ◽  
Chemical Reagents ◽  
Froth Layer

Seafloor Massive Sulfides (SMS), which were formed by deposition of precipitates from hydrothermal fluids vented from seafloor, is one of unconventional mineral resources beneath deep seafloors in the world. The authors have proposed the concept of seafloor mineral processing for development of SMS, where useful minerals included in SMS ores are separated on seafloor to be lifted while the remaining gangue is disposed on seafloor in appropriate ways. To apply column flotation, one of conventional methods in mineral processing, to seafloor mineral processing, the authors carried out simulating experiments of column flotation on deep seafloor using ores including copper, iron, lead and zinc as metallic elements. Prior to the experiments at high pressures, preparatory experiments at the atmospheric pressure were carried out to find out the optimum condition of the properties of pulp, a mixture of feed ore, water and chemical reagents. In flotation experiments at high pressures, formation and overflow of froth layer by bubbling were observed at 1MPa in both of pulps with pure water and artificial seawater. The analytical data showed that the concentration of metallic elements such as copper and zinc in the concentrates recovered from the experiments was higher than that in the feed ores while the concentration of silicon and calcium, which are assigned to gangue, in the concentrates was lower than that in the feed ores. These results suggest that column flotation can be applied to operation on seafloor.

scholarly journals Coating Matters: Review on Colloidal Stability of Nanoparticles with Biocompatible Coatings in Biological Media, Living Cells and Organisms

2018 ◽  
Vol 25 (35) ◽  
pp. 4553-4586 ◽  
Author(s):  
Jonas Schubert ◽  
Munish Chanana
Keyword(s):  
Colloidal Stability ◽  
Biological Fluids ◽  
Chemical Properties ◽  
Coating Material ◽  
Living Systems ◽  
Biological Media ◽  
Coating Materials ◽  
Physico Chemical ◽  
Environment Temperature ◽  
To Come

Within the last two decades, the field of nanomedicine has not developed as successfully as has widely been hoped for. The main reason for this is the immense complexity of the biological systems, including the physico-chemical properties of the biological fluids as well as the biochemistry and the physiology of living systems. The nanoparticles’ physicochemical properties are also highly important. These differ profoundly from those of freshly synthesized particles when applied in biological/living systems as recent research in this field reveals. The physico-chemical properties of nanoparticles are predefined by their structural and functional design (core and coating material) and are highly affected by their interaction with the environment (temperature, pH, salt, proteins, cells). Since the coating material is the first part of the particle to come in contact with the environment, it does not only provide biocompatibility, but also defines the behavior (e.g. colloidal stability) and the fate (degradation, excretion, accumulation) of nanoparticles in the living systems. Hence, the coating matters, particularly for a nanoparticle system for biomedical applications, which has to fulfill its task in the complex environment of biological fluids, cells and organisms. In this review, we evaluate the performance of different coating materials for nanoparticles concerning their ability to provide colloidal stability in biological media and living systems.

scholarly journals Plasmonic Oligomers With Tunable Conductive Nanojunctions

2019 ◽  
Author(s):  
Xiaoyan Li ◽  
Jieli Lyu ◽  
Claire Goldmann ◽  
Mathieu Kociak ◽  
Doru Constantin ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Infrared Region ◽  
Original Method ◽  
Second Step ◽  
Nanometer Scale ◽  
Mid Infrared ◽  
Oligomer Formation ◽  
Colloidal Chemistry ◽  
Vis Spectroscopy ◽  
Electron Energy Loss

<p>Plasmonic particles can be welded together, but controlling the metallurgy of the hotspots is a challenge in colloidal chemistry. In this paper, we demonstrate an original method that connects gold particles to their neighbors by another metal of choice. To achieve this goal, we first assemble gold bipyramids in a tip-to-tip configuration, yielding short chains of variable length. The good colloidal stability and surface accessibility make the nanochains suitable seeds to grow metallic junctions in a second step. We follow the oligomer formation and the deposition of the second metal (i.e. silver or palladium) <i>via</i> UV/Vis spectroscopy and we map the plasmonic properties of the nanostructures at nanometer scale using electron energy loss spectroscopy. The formation of silver bridges leads to a huge redshift of the longitudinal plasmon modes into the mid-infrared region, while the addition of palladium results in a redshift accompanied by significant plasmon damping. </p>

Formation and characterization of silica-coated HAP particles

2012 ◽  
Vol 19 (2) ◽  
pp. 107-112
Author(s):  
Hongxin Wang ◽  
Xiaoming Chen ◽  
Dongji Cheng
Keyword(s):  
Colloidal Stability ◽  
Particle Surface ◽  
Silica Coating ◽  
Esterification Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Infrared Spectral ◽  
Hydrolysis Of

AbstractNanophase hydroxyapatite (HAP) particles were coated with silica via the hydrolysis of tetraethyl orthosilicate after a dodecyl alcohol based esterification reaction. The nanocomposite particles were characterized by transmission electron spectroscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, thermogravimetry and differential scanning calorimetry, sedimentation time and zeta potential (ζ) studies. A sequential change in infrared spectral features characteristic of HAP was accompanied by an increase in features characteristic of silica as revealed by FTIR. The silica coating enhanced the colloidal stability of HAP in aqueous suspensions. This behavior can be explained based on a heterocoagulation coating mechanism in which silica clusters adsorb onto the HAP particle surface.

Soap-Free Emulsion Polymerization for New Building Sealant

2012 ◽  
Vol 446-449 ◽  
pp. 35-38
Author(s):  
Jing Jing Li ◽  
Guang Ying Gao ◽  
Yu Fei Wang ◽  
Lin Guo
Keyword(s):  
Colloidal Stability ◽  
Colloidal Particle ◽  
Molecular Design ◽  
Raw Materials ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Process Conditions ◽  
Core Shell ◽  
Soap Free Emulsion Polymerization ◽  
Polymer Latex

In order to obtain functional polymer latex with surface carboxyl groups which can enhance colloidal stability and alkali viscosity, a molecular design was carried out and novel latex for building sealant was synthesized by using the technology of soap-free emulsion and core-shell polymerization. The monomer component, initiator, reaction temperature, adding mode of raw materials, carboxylation of colloidal particle and application of cross-linking reaction in molecular design were investigated. The suitable formula and process conditions were defined.

scholarly journals 635 A novel site-directed chemical conjugation technology confers antitumor activity via native Fc receptor to plasma immunoglobulin by attaching tumor binders

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A671-A671
Author(s):  
Christian Vidal ◽  
Michael Cukan ◽  
Rajat Varma ◽  
Lawrence Iben ◽  
Tanya Berbasova ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Chemical Engineering ◽  
Covalent Bond ◽  
Pharmacokinetic Profile ◽  
Release Mechanism ◽  
Chemical Reagents ◽  
Cell Counts ◽  
Chemical Conjugation

BackgroundWe describe KPMW101, which was created by chemical conjugation of a CD38-specific binder to clinical grade intravenous immunoglobulin (IvIg) pooled from healthy donors. Kleo’s MATETM technology enables efficient site-directed chemical conjugation to ‘off-the-shelf’ IvIg and allows the development of antitumor agents with rapidly introduced target specificity. Our platform allows for chemical engineering of existing IvIg in a cost-efficient manner. This technology relies on synthetic compounds that consists of antibody binder with react-and-release mechanism.MethodsDesign of synthetic chemical reagents included antibody binding group capable of covalent bond formation with specific lysine, CD38 binding moiety proven to work in our clinical candidate KP1237, and tunable non-cleavable linker. Conjugation efficiency to polyclonal IvIg was evaluated using LC-MS analysis of IdeZ-digests. The binding of CD38, CD16a, and FcRn were determined by ELISA and BLI.For in vitro ADCC assays, PBMCs provided NK effector function. Daudi (CD38+) B lymphoblast cells were treated with KPMW101 or IvIg, PBMCs were introduced and incubated for 18h, and target cellular death was measured. For an in vivo IP macrophage lavage model of ADCP, SCID mice were implanted IP with CFSE-labeled Daudi cells. Mice were injected with IvIg or KPMW101 (0.21, 0.625, 1.875 mg/kg) SQ, and tumor cell counts were measured by flow cytometry. The pharmacokinetic profile of in vivo KPMW101 was determined from blood and analyzed utilizing a human Ig isotyping array.ResultsSynthetic chemical reagents with multiple linker types have been conjugated to IvIg and evaluated in biochemical assays. KPMW101 showed the highest conjugation efficiency. Binding affinity of KPMW101 to CD38 was 27nM. ELISA results show KPMW101 binds to CD16a and FcRn, indicating that conjugation does not interfere with FcR binding.In vitro ADCC results demonstrate that KPMW101 elicited CD38+ target cell killing with an EC50 of 0.91–2.09nM.In vivo studies showed that KPMW101 resulted in a 49.9–63.5% reduction of tumor cells. Pharmacokinetic profile showed stability of KPMW101 throughout the 144-hour study, whereby IgG1, IgG2, IgG3, and IgG4 isotypes were detectable.ConclusionsKPMW101 is created by chemical conjugation of CD38-specific binder to IvIg using our proprietary MATETM technology, maintaining native binding to FcRs via the Fc domain. This ensures the stability of the molecule and retains immune-mediated mechanisms of action. KPMW101 induces IvIg to adopt Fc effector mechanisms like ADCC and ADCP. Our in vitro data and in vivo studies confirm KPMW101 ability to kill tumor cells, making IvIg into an active antitumor therapeutic agent.

scholarly journals Corrosion protection of oil production and refinery equipment

2007 ◽  
Vol 1 (1) ◽  
pp. 45-54
Author(s):  
Petro Topilnitskij ◽  
Keyword(s):  
Corrosion Inhibitors ◽  
Process Conditions ◽  
Industrial Equipment ◽  
Corrosion Prevention ◽  
Chemical Reagents ◽  
Refrigeration Equipment ◽  
Equipment Corrosion ◽  
Surface Active ◽  
Technological Means ◽  
Active Substances

The review of methods of industrial equipment corrosion prevention is presented. Application of technological means using chemical reagents and surface-active substances is considered, namely dehydration and desalting of hydrocarbon products of deposits by surface-active substances – so called demulsifiers. Corrosion inhibitors and neutralizing agents for protection of condensation-refrigeration equipment and overheads of atmospheric columns are examined. The amount of reagents to be used and the process conditions were determined.

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