scholarly journals Production of Mg-Li alloys by aluminothermic vacuum reduction

2020 ◽  
Vol 56 (1) ◽  
pp. 43-49
Author(s):  
Y.-W. Wang ◽  
J. You ◽  
A.-G. Wang ◽  
J.-P. Peng ◽  
Y.-Z. Di

Mg?Li alloys are the lightest metallic construction materials and one of the most representative light alloys. The process of producing Mg?Li alloys by vacuum aluminothermic reduction, using magnesite and lithium carbonate as raw materials, was studied. The influence of reduction parameters on the extents of reduction of MgO and Li2O was investigated. The results show that Mg?Li alloys can be produced by vacuum aluminothermic reduction using calcined magnesite and lithium carbonate. MgO was relatively easier to reduce by aluminum than Li2O. Almost all MgO was reduced to Mg and more than 96% of Li2O was reduced to Li. The main phase in the reduction slag was Li2O?5Al2O3. The reaction mechanism was discussed. Vacuum aluminothermic reduction can be considered as a highly efficient and environmental friendly method for producing Mg?Li alloys.

2020 ◽  
Vol 10 (1) ◽  
pp. 16-19
Author(s):  
Tasnia Ahmed ◽  
Md Aftab Uddin

Spreads are used widely for making the fast foods more amazing and tasty. Varieties and cross combinations of ingredients are used to make many flavours of fast foods. Different restaurants prepare their signature spreads for attracting people but this can cause opposite result if not prepared using high quality raw materials and proper hygienic conditions are not maintained. Current study was conducted on ten different types of spreads (pesto, cilantro, queso, tomato sauce, peanut butter, honey, mustard, cream cheese, chocolate sauce and butter) which are used by the local restaurants in Dhaka city, Bangladesh. Almost all the samples (nine out of ten) harbored total viable bacteria exceeding the standard limit. Four spread samples showed high fungal count (102 cfu/gm). Four samples showed to be positive (˃101/ml recommended acceptable count) for Escherichia coli and Klebsiella spp. which indicates that these spread cannot be recommended for public consumption. Among all the samples examined, only chocolate sauce showed acceptable result without the presence of coliforms, Staphylococcus spp. and Pseudomonas spp. This finding suggests proper maintenance of sanitation in spread preparation and selling area. A proper guidelines and monitoring can help keep up the quality of food additives. Stamford Journal of Microbiology, Vol.10 (1) 2020: 16-19


2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.


2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.


2020 ◽  
Vol 39 (1) ◽  
pp. 107-116
Author(s):  
Hongyang Wang ◽  
Kai Dong ◽  
Rong Zhu

AbstractThe reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zincrich dust process are studied. The dust collected from a steelwork contains 63.8% zinc and 3.18% chlorine (mass percent), of which, almost all zinc elements exist in ZnO and ZnCl2 forms, and all the chlorine elements are stored in ZnCl2. When the dust is roasted at above 732∘C in an air atmosphere, the ZnCl2 in the steelmaking zinc-rich dust is volatilized into steam and then oxidized into ZnO. Finding the position where the chemical reaction occurs is the key to determining the reaction mechanisms of dechlorination and [Zn] reclaiming. In this study, two groups of thermal experiments are designed and executed for roasting in different atmosphere environments and at different roasting temperatures. Based on the experiment results, the mechanism model is discussed and built, and the reaction of dechlorination and [Zn] reclaiming is shown to be a multi-step process. Because O2 from the air cannot transmit into the dust particle interior or dust bed effectively, the chemical reaction of [Zn] reclaiming occurs in the external gas environment outside of the dust, where the [Zn] recalcining reaction should be limited by the dynamics of new nucleation of ZnO solids.


2020 ◽  
Vol 10 (6) ◽  
pp. 1609-1618 ◽  
Author(s):  
Chao Zhang ◽  
Jiandong Liu ◽  
Xingliang Liu ◽  
Shiai Xu

Reaction mechanism for the higher photocatalytic performance of H2 production of g-C3N4NSs/TC1 under visible light irradiation (λ ≥ 400 nm).


2014 ◽  
Vol 1000 ◽  
pp. 12-15
Author(s):  
Jiří Švec ◽  
Tomáš Opravil ◽  
Jiří Másilko

Reusing and recycling of secondary raw materials from high-volume industrial productions (especially form construction materials and binders fabrications) is very important way of conserving environment and it is also interesting from the economical point of view. The production of common hydraulic binders, especially Portland cement, burdens the environment with considerable amount of combustion gases and consumes energy in massive scale. Alternative (low – energy) binder can be used as Portland cement substitution in applications with lower mechanical properties requirements. Mined limestone wash sediments contain large amount of clay components, but there is also indispensable share of fine calcite. This composition makes these sediments a promising material for the preparation of hydraulic binders as Roman cement or hydraulic lime.


2014 ◽  
Vol 1051 ◽  
pp. 139-142 ◽  
Author(s):  
V.S. Srinivasan ◽  
S. Rajendra Boopathy ◽  
B. Vijaya Ramnath

The present technological development makes us to find and fabricate new materials to replace existing materials. Also, the need for environmental friendly, easily biodegradable material plays prime role in determining the raw materials. In this paper Flax and Kenaf fibres are used as the suspending matrix to form hybrid composite with epoxy resin. Hand layup technique is carried out in this work to fabricate composite laminate. The double shear property is evaluated. The result shows that the hybrid composite shows better property than mono fiber composites.


2021 ◽  
Vol 896 ◽  
pp. 45-50
Author(s):  
Lian Yi Huo ◽  
Xue Tao Shi ◽  
Si Ming Chen ◽  
Meng Yao Zhang

Hyperbranched polymers (HBPs) have been applied in various fields because of its outstanding biodegradability and biocompatibility. At present, there are a variety of methods that are used to fabricate HBPs, such as polycondensation, reactive polymerization and ring-opening polymerization according to reaction mechanism. These methods are all environmental-friendly and high-efficient to generate HBPs, and are valuable for industrialization. In this work, we conclude some common methods of HBPs fabrication and make the comparison between them to analyze their advantages and disadvantages, which contribute in how to improve the synthesis process in the future research.


Author(s):  
Chao Xu ◽  
Haibo Li

Interfacial solar steam generation (ISSG) is considered to be a highly efficient and environmental-friendly desalination technique for producing potable water. Herein, we demonstrate the high-performance SSG enabled by the porous...


2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Mihail Doynov ◽  
Tsvetan Dimitrov ◽  
Maria Kokkori

The synthesis of arsenic-free ceramics from industrial waste is studied. Samples of waste containing siliceous material passed the exploitation leap-guard layer shift reactor whose main oxide is -Al2O3and, with the addition of natural raw materials and pure oxide, arsenic-free ceramics were synthesized with thermal and electrical properties related to the main phase of spinel group minerals; solid solutions were also formed in the process of synthesis. Insulating properties were established by successive heating and cooling of the specimen for six cycles. Electrical insulating properties were established by the method of resistance to arcing. The relative density was determined by hydrostatic method and diffusion lines of molecules at the main phase were characterized by X-ray diffraction analysis. The experimental procedures followed in this study allowed mixing on a molecular level due to the small dimensions of the crystallite which in turn explains the relatively high density.


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