Research on New Thermal Reduction Process of Magnesium Preparation at Ordinary Pressure with Serpentine as Raw Material

2011 ◽  
Vol 402 ◽  
pp. 380-385
Author(s):  
De Hong Xia ◽  
Ling Ren ◽  
Yi Fan Li
Keyword(s):  
Continuous Production ◽  
High Vacuum ◽  
Reduction Process ◽  
Magnesium Content ◽  
Thermal Reduction ◽  
Raw Material ◽  
Reaction Conditions ◽  
Operation Costs ◽  
High Vacuum Condition ◽  
New Process

The traditional silicothermic process of magnesium metallurgy with dolomite at high temperature and under high vacuum condition results in high operation costs, discontinuous production and huge production consumption. Based on this, a new thermal reduction process of magnesium preparation is proposed with serpentine as raw material at ordinary pressure. It is shown by thermodynamic analysis that the calcined products of serpentine is the compound of 2MgO•SiO2 and MgO•SiO2. Furthermore, the thermal reduction process at ordinary pressure is determined by using calcined products of serpentine as raw material, CaC2 as reductant and CaO as additive. Comparing with traditional silicothermic process, the new process has many advantages due to higher magnesium content of serpentine, lower price of the reductant CaC2, lower reaction temperature in calcined and thermal reduction process, and ordinary pressure reaction conditions for continuous production.

Preparation of Mg-Sr Alloys Using Vacuum Reduction: A Thermodynamics Approach

2007 ◽  
Vol 546-549 ◽  
pp. 463-466 ◽  
Author(s):  
Wei Dong Xie ◽  
Xiao Dong Peng ◽  
Qun Yi Wei ◽  
Hua Nie ◽  
Shou Cheng Wang
Keyword(s):  
Free Energy ◽  
Oxygen Potential ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Reduction Temperature ◽  
Mixing Process ◽  
New Process ◽  
Reduction Thermodynamics ◽  
Oxygen Potential Diagram

At the present Mg-Sr alloy is usually produced by alloy mixing process or melt-leaching-reduction process which has low productivity. A new process has been developed termed “Preparation Mg-Sr alloys using vacuum thermal reduction”. The principle and procedure of the new process were discussed in this paper. The reduction thermodynamics was analyzed, including establishing the oxygen potential diagram of Sr, Mg, Si and Al, determination of main reactions, and evaluation of Gibbs free energy in vacuum. The results showed that Mg-Sr alloys can be obtained by synchronous reduction of SrO and MgO from a mixture of MgO, SrO, Si, CaO. The equipment, reduction temperature and vacuum for the new process have been also discussed.

Thermodynamic Analysis of Magnesium Produced by CaC2 under Ordinary Pressure

2011 ◽  
Vol 354-355 ◽  
pp. 304-309
Author(s):  
De Hong Xia ◽  
Ling Ren ◽  
Bin Shu
Keyword(s):  
Free Energy ◽  
Continuous Production ◽  
Thermal Reduction ◽  
Point Of View ◽  
Initial Reaction ◽  
High Grade ◽  
New Process ◽  
Technological Level ◽  
Main Component ◽  
Optimal Reaction

In this paper, a new process of using high grade ores, such as magnesite and water magnesium stone etc, to produce magnesium is proposed from the thermodynamic point of view. For the ores, the main component of calcined products is MgO. Considering the reaction activity, price and material stability, CaC2 is chosen as the reductant in the new process. Furthermore, the optimal reaction is determined as the reduction of MgO by CaC2 adding SiO2 based on the principle of Gibbs free energy. It is found that the initial reaction temperature is 947°C under ordinary pressure showing the reaction taking place without vacuum condition. Compared with the traditional silicothermic process, the new process is not only simple but also can achieve continuous production due to the thermal reduction under ordinary pressure, as a result that it is easy to industrial application in the present technological level and conditions.

scholarly journals The COOL-Process—A Selective Approach for Recycling Lithium Batteries

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259
Author(s):  
Sandra Pavón ◽  
Doreen Kaiser ◽  
Robert Mende ◽  
Martin Bertau
Keyword(s):  
Lithium Ion ◽  
Global Market ◽  
Raw Material ◽  
Mass Ratio ◽  
Reaction Conditions ◽  
Cool Process ◽  
Secondary Sources ◽  
Selective Approach ◽  
Valuable Metals ◽  
Housing Materials

The global market of lithium-ion batteries (LIB) has been growing in recent years, mainly owed to electromobility. The global LIB market is forecasted to amount to $129.3 billion in 2027. Considering the global reserves needed to produce these batteries and their limited lifetime, efficient recycling processes for secondary sources are mandatory. A selective process for Li recycling from LIB black mass is described. Depending on the process parameters Li was recovered almost quantitatively by the COOL-Process making use of the selective leaching properties of supercritical CO2/water. Optimization of this direct carbonization process was carried out by a design of experiments (DOE) using a 33 Box-Behnken design. Optimal reaction conditions were 230 °C, 4 h, and a water:black mass ratio of 90 mL/g, yielding 98.6 ± 0.19 wt.% Li. Almost quantitative yield (99.05 ± 0.64 wt.%), yet at the expense of higher energy consumption, was obtained with 230 °C, 4 h, and a water:black mass ratio of 120 mL/g. Mainly Li and Al were mobilized, which allows for selectively precipitating Li2CO3 in battery grade-quality (>99.8 wt.%) without the need for further refining. Valuable metals, such as Co, Cu, Fe, Ni, and Mn, remained in the solid residue (97.7 wt.%), from where they are recovered by established processes. Housing materials were separated mechanically, thus recycling LIB without residues. This holistic zero waste-approach allows for recovering the critical raw material Li from both primary and secondary sources.

scholarly journals Highly Sensitive Hybrid Nanostructures for Dimethyl Methyl Phosphonate Detection

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 648
Author(s):  
Sanjeeb Lama ◽  
Jinuk Kim ◽  
Sivalingam Ramesh ◽  
Young-Jun Lee ◽  
Jihyun Kim ◽  
...  
Keyword(s):  
Chemical Warfare Agents ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Hybrid Nanostructures ◽  
Nitrogen Doped ◽  
Saw Sensor ◽  
Quartz Crystal Microbalance Sensor ◽  
Warfare Agents ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Nanostructured materials synthesized by the hydrothermal and thermal reduction process were tested to detect the dimethyl methylphosphonate (DMMP) as a simulant for chemical warfare agents. Manganese oxide nitrogen-doped graphene oxide with polypyrrole (MnO2@NGO/PPy) exhibited the sensitivity of 51 Hz for 25 ppm of DMMP and showed the selectivity of 1.26 Hz/ppm. Nitrogen-doped multi-walled carbon nanotube (N-MWCNT) demonstrated good linearity with a correlation coefficient of 0.997. A comparison between a surface acoustic wave and quartz crystal microbalance sensor exhibited more than 100-times higher sensitivity of SAW sensor than QCM sensor.

Immobilized Recombinant Chitinase and its Inhibition Effect on Botrytis Cinerea

2014 ◽  
Vol 936 ◽  
pp. 674-680
Author(s):  
Na Zhang ◽  
Rui Xiang Yan ◽  
Wen Qiang Guan
Keyword(s):  
Reduction Method ◽  
Average Diameter ◽  
Thermal Reduction ◽  
Gray Mold ◽  
Magnetic Carrier ◽  
Reaction Conditions ◽  
Recombinant Chitinase ◽  
Crude Enzyme Solution ◽  
Infrared Spectrometer

To isolate recombinant chitinase quickly and boost its anti-fungi activities in vitro, functional magnetic nanometer carrier was used to immobilize recombinant chitinase from the crude enzyme solution and immobilized recombinant chitinase was applied to test whether it would inhibit the growth of gray mold from fruits. In this study, the carboxyl magnetic carrier was produced by solvent thermal reduction method and characterized by scanning electron microscope (SEM) and fourier transform infrared spectrometer (FTIR). Then, the carboxyl magnetic carrier activated by EDC/NHS was applied to immobilize recombinant chitinase and the immobilization efficiency was investigated by quantitative analysis. To obtain the highest immobilization efficiency, reaction conditions were optimized through combining different pH, temperature and reaction period. The results show that the surface of magnetic carrier was successfully carboxyl and the average diameter was 200nm. The immobilization efdiciency could reach the peak 64.43% after 7h reaction at the condition of pH 6 and 25°C. It also shows that immobilized recombinant chitinase can significantly inhibit the growth of gray mold isolated from table grape compared with the enzyme without immobilization with magnetic nanometer carrier.

scholarly journals Insights into thermal reduction of the oxidized graphite from the electro-oxidation processing of nuclear graphite matrix

RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 567-579 ◽  
Author(s):  
Gengyu Zhang ◽  
Mingfen Wen ◽  
Shuwei Wang ◽  
Jing Chen ◽  
Jianchen Wang
Keyword(s):  
Temperature Dependence ◽  
Structural Transformation ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Oxygen Species ◽  
Nuclear Graphite ◽  
Graphite Matrix ◽  
Electro Oxidation ◽  
Oxidized Graphite

Temperature-dependence of structural transformation of oxidized graphite from the electro-oxidation processing of nuclear graphite matrix have been studied. Meanwhile, the mechanism of dissociation of oxygen species on the thermal reduction process has been suggested.

Exoelectron emission from unexcited metallic glasses Fe78B13Si9 during heat treatment

1992 ◽  
Vol 7 (6) ◽  
pp. 1396-1399 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Tadayoshi Kubozoe ◽  
Yoshikazu Nakamura
Keyword(s):  
Heat Treatment ◽  
Metallic Glasses ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Exoelectron Emission ◽  
Radiation Chemical ◽  
Temperature Range ◽  
High Vacuum Condition ◽  
Before And After ◽  
Ultra High Vacuum Condition

Exoelectron emission from the surface of unexcited metallic glasses Fe78B13Si9 during heat treatment has been studied under ultra high vacuum condition. In the first heating cycle, exoelectrons are emitted from the as-cast ribbon in the temperature range from approximately 423 K to 773 K (150 °C to 500 °C), although the surface of the specimen is not excited by ionizing radiation, chemical processes, or mechanical treatments prior to measurements. In the second and subsequent heating cycles, however, there is no anomalous emission observed in the same temperature range. In order to elucidate the mechanism of emission, the surface of the specimen is observed by the atomic force microscope (AFM) before and after measurements. In the AFM image, many crystallites in the amorphous matrix can be found in the surface of the heated specimen. These experimental results show that exoelectrons are emitted in the same temperature range as the early stages of crystallization on the surface of metallic glasses. We hypothesize that the two effects are correlated.

scholarly journals Facile preparation and excellent microwave absorption properties of an RGO/Co0.33Ni0.67 lightweight absorber

RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43831-43838 ◽  
Author(s):  
Hai Pan ◽  
Mingzhen Xu ◽  
Qing Qi ◽  
Xiaobo Liu
Keyword(s):  
Microwave Absorption ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Thermal Method ◽  
Absorption Properties ◽  
One Pot ◽  
Microwave Absorption Properties ◽  
Facile Preparation

A lightweight absorber with an ordered sandwich-like structure was fabricated using a simple one-pot solvent-thermal method and thermal reduction process.

On the carbo-thermal reduction of silica for carbon nano-fibre formation via CVD

2011 ◽  
Vol 1284 ◽  
Author(s):  
Alicja Bachmatiuk ◽  
Felix Börrnert ◽  
Imad Ibrahim ◽  
Bernd Büchner ◽  
Mark H. Rümmeli
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Carbothermal Reduction ◽  
Carbon Nanostructures ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Thermal Reduction ◽  
Fibre Formation ◽  
Quartz Substrates

ABSTRACTThe formation of carbon nanostructures using silica nanoparticles from quartz substrates as a catalyst in an aerosol assisted chemical vapor deposition process was examined. The silica particles are reduced to silicon carbide via a carbothermal reduction process. The recyclability of the explored quartz substrates is also presented. The addition of triethyl borate improves the efficiency of the carbothermal reduction process and carbon nanotubes formation. Moreover, the addition of hydrogen during the chemical vapor deposition leads to the helical carbon nanostructures formation.

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