scholarly journals The Effect of the Surface Energy of Water Glass on the Fluidity of Sand

2020 ◽  
Vol 58 (5) ◽  
pp. 319-325
Author(s):  
Min A Bae ◽  
Man Sig Lee ◽  
Jae Ho Baek
Keyword(s):  
Surface Tension ◽  
Water Glass ◽  
Water Resistance ◽  
Environmental Issues ◽  
Environmental Standards ◽  
Practical Application ◽  
Inorganic Binder ◽  
Flow Test ◽  
Silicate Chemistry ◽  
Casting Industry

In recent years, the metal casting industry has sought to meet ever more stringent environmental standards. Inorganic binders based on silicate chemistry have many advantages with respect to environmental issues, but often suffer from reduced strength, burn-on and poor water-resistance. In particular, when sand is mixed with a water glass based inorganic binder, it adversely affects fluidity. In this study, a Powder flow test (PFT) analysis was conducted to confirm the effect of the surface tension of water glass on mixed sand. Certain additives were selected as surfactants to lower the surface tension of the water glass. The characteristics of the samples were measured using the PFT. A correlation between the surface tension of the water glass and the fluidity of the mixed sand was established. We then evaluated the effect of the inorganic binder on core strength. Using the surfactants, the fluidity of the mixed sand increased by 66%. However, strength and water resistance were reduced by approximately 45%. As a result, it was found that when 1.5% of surfactant was added, the resulting fluidity and humidity strength characteristics produced a mixed sand with good properties. Water glass with improved fluidity can produce a high quality core and mold. Finally, we used a practical application prove that an inorganic binder can replace organic binders in foundry cores.

scholarly journals Encapsulate α-MnO2 nanofiber within graphene layer to tune surface electronic structure for efficient ozone decomposition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guoxiang Zhu ◽  
Wei Zhu ◽  
Yang Lou ◽  
Jun Ma ◽  
Wenqing Yao ◽  
...  
Keyword(s):  
Graphene Layer ◽  
Water Resistance ◽  
Catalyst Design ◽  
Ozone Decomposition ◽  
Oxygen Species ◽  
Ozone Molecule ◽  
Practical Application ◽  
Surface Electronic Structure ◽  
Reaction Barriers ◽  
Excellent Stability

AbstractMajor challenges encountered when developing manganese-based materials for ozone decomposition are related to the low stability and water inactivation. To solve these problems, a hierarchical structure consisted of graphene encapsulating α-MnO2 nanofiber was developed. The optimized catalyst exhibited a stable ozone conversion efficiency of 80% and excellent stability over 100 h under a relative humidity (RH) of 20%. Even though the RH increased to 50%, the ozone conversion also reached 70%, well beyond the performance of α-MnO2 nanofiber. Here, surface graphite carbon was activated by capturing the electron from inner unsaturated Mn atoms. The excellent stability originated from the moderate local work function, which compromised the reaction barriers in the adsorption of ozone molecule and the desorption of the intermediate oxygen species. The hydrophobic graphene shells hindered the chemisorption of water vapour, consequently enhanced its water resistance. This work offered insights for catalyst design and would promote the practical application of manganese-based catalysts in ozone decomposition.

Waste Plastic Sachet as Alternative Anti-Corrosion Filler for Iron Oxide in Resin Coatings

2021 ◽  
Vol 877 ◽  
pp. 9-14
Author(s):  
Francis Darwin T. Eugenio ◽  
Bryan B. Pajarito
Keyword(s):  
Corrosion Resistance ◽  
Iron Oxide ◽  
Film Thickness ◽  
Iron Oxides ◽  
Water Resistance ◽  
Inorganic Compounds ◽  
Environmental Issues ◽  
Metal Coatings ◽  
Waste Plastic ◽  
Coating Mixture

Iron oxides and similar inorganic compounds have served as anti-corrosion fillers for metal coatings. Environmental issues related to the mining of metallic fillers have stimulated interest in alternative fillers such as organic fillers. This paper explores the use of comminuted waste plastic sachets (WPS) as an anti-corrosion filler to resin-based metal coating. Mixture design of experiment was used to study the effect of iron oxide-WPS blends on the film thickness, viscosity, corrosion behavior, and water resistance of the coating. Results show that the film thickness was affected by the presence of iron oxide while the viscosity of the coating was affected by high loads of WPS. Among all coatings, the blend containing 25% iron oxide and 75% WPS produced the highest corrosion resistance. In conclusion, comminuted WPS provided additional corrosion resistance and could serve as an alternative anti-corrosion filler.

scholarly journals Allyl glycidyl ether-modified animal glue binder for improved water resistance and bonding strength in sand casting

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Chen-chen Fan ◽  
Qian Tang
Keyword(s):  
Tensile Strength ◽  
Bonding Strength ◽  
Room Temperature ◽  
Water Resistance ◽  
Glycidyl Ether ◽  
Animal Glue ◽  
Practical Application ◽  
Foundry Industry ◽  
Dog Bone ◽  
Allyl Glycidyl Ether

This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength. An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength. Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature. The proposed method saves energy and is environmentally friendly and inexpensive. Compared with unmodified animal glue binder, standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa, flowability of 1.95 g, better water resistance (a lower decrease in tensile strength at 25 °C and relative humidity of 60%), and good collapsibility. This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.

scholarly journals Method of the Moulding Sands Binding Power Assessment in Two-Layer Moulds Systems / Metoda oceny wielkości siły wiązania mas w układzie form dwuwarstwowych

2013 ◽  
Vol 13 (2) ◽  
pp. 39-42
Author(s):  
M. Holtzer ◽  
D. Drożyński ◽  
A. Bobrowski ◽  
J. Makselon
Keyword(s):  
Tensile Strength ◽  
Chemical Reaction ◽  
Water Glass ◽  
Organic Binder ◽  
High Quality ◽  
Casting Surface ◽  
Inorganic Binder ◽  
Resol Resin ◽  
Moulding Sand ◽  
Binding Power

Abstract More and more foundry plants applying moulding sands with water-glass or its substitutes for obtaining the high-quality casting surface at the smallest costs, consider the possibility of implementing two-layer moulds, in which e.g. the facing sand is a sand with an organic binder (no-bake type) and the backing sand is a sand with inorganic binder. Both kinds of sands must have the same chemical reaction. The most often applied system is the moulding sand on the water-glass or geopolymer bases - as the backing sand and the moulding sand from the group of self-hardening sands with a resol resin - as the facing sand. Investigations were performed for the system: moulding sand with inorganic GEOPOL binder or moulding sand with water glass (as a backing sand) and moulding sand, no-bake type, with a resol resin originated from various producers: Rezolit AM, Estrofen, Avenol NB 700 (as a facing sand). The LUZ apparatus, produced by Multiserw Morek, was adapted for investigations. A special partition with cuts was mounted in the attachment for making test specimens for measuring the tensile strength. This partition allowed a simultaneous compaction of two kinds of moulding sands. After 24 hours of hardening the highest values were obtained for the system: Geopol binder - Avenol resin.

scholarly journals Study of "Saralsk" Deposit for Practical Applications in Construction

2021 ◽  
Vol 1 (1) ◽  
pp. 3-6
Author(s):  
Avetik Artavazd Arzumanyan ◽  
Vardan Grigor Tadevosyan ◽  
Nelli Gagik Muradyan ◽  
Hovhannes Vachagan Navasardyan
Keyword(s):  
Microscopic Study ◽  
Frost Resistance ◽  
Water Resistance ◽  
Structural Features ◽  
Practical Application ◽  
Petrographic Composition ◽  
Secondary Minerals ◽  
Practical Applications ◽  
Stone Materials ◽  
Technical Properties

In article the results of research of structural features and technical properties of andesite - basalt stone rock of the “Saralsk” deposit are given. The material is estimated by its mineral - petrographic composition, and the cuts/refinements of stone materials have been made for the microscopic study of mineral-petrographic composition. Researches are conducted according to requirements of acting standards and as a result, it became clear, that the rock consists basically of minerals opacitized hornblende and plagioclase, it doesn't contain any no secondary minerals such as hydroxides of iron, chlorites, epidote, quartz, saricite, etc. Petrographic researches have allowed to determine the species of stone rock. The density, strength, water resistance and frost resistance of stone rock are studied. The suitability of the material for practical application in construction, including for external works, is revealed.

scholarly journals Mycoremediation of PCBs by Pleurotus ostreatus: Possibilities and Prospects

2019 ◽  
Vol 9 (19) ◽  
pp. 4185 ◽  
Author(s):  
Se Chul Chun ◽  
Manikandan Muthu ◽  
Nazim Hasan ◽  
Shadma Tasneem ◽  
Judy Gopal
Keyword(s):  
Cost Effectiveness ◽  
Polychlorinated Biphenyls ◽  
Pleurotus Ostreatus ◽  
Industrial Development ◽  
White Rot Fungi ◽  
Environmentally Friendly ◽  
Environmental Issues ◽  
White Rot ◽  
Practical Application ◽  
Human Welfare

With the rising awareness on environmental issues and the increasing risks through industrial development, clean up remediation measures have become the need of the hour. Bioremediation has become increasingly popular owing to its environmentally friendly approaches and cost effectiveness. Polychlorinated biphenyls (PCBs) are an alarming threat to human welfare as well as the environment. They top the list of hazardous xenobiotics. The multiple effects these compounds render to the niche is not unassessed. Bioremediation does appear promising, with myco remediation having a clear edge over bacterial remediation. In the following review, the inputs of white-rot fungi in PCB remediation are examined and the lacunae in the practical application of this versatile technology highlighted. The unique abilities of Pleurotus ostreatus and its deliverables with respect to removal of PCBs are presented. The need for improvising P. ostreatus-mediated remediation is emphasized.

The Effect of Surfactant and Alkali on the Surface Tension of Simulated Solutions of Alkali Activated Slag Cement System

2011 ◽  
Vol 399-401 ◽  
pp. 1246-1250
Author(s):  
Xian Feng Liu ◽  
Jia Hui Peng ◽  
Chang Hui Yang ◽  
Yu Yan Shu ◽  
Da Chang Wu
Keyword(s):  
Surface Tension ◽  
Water Glass ◽  
High Viscosity ◽  
Heat Of Hydration ◽  
Slag Cement ◽  
Alkali Activated Slag ◽  
Cement System ◽  
Cement And Concrete ◽  
Activated Slag ◽  
Alkali Activated

Alkali activated slag cement and concrete are high strength, rapid hardening, low heat of hydration, good durability and so on. Whereas, too high viscosity and bad workability of the fresh mixture is the crux of the matter to embarrass application of alkali-activated slag cement and concrete. Development of special superplasticizer for alkali activated slag cement and concrete is a worth exploring way to solve the problem, and the study on the surface tension of simulated solutions of alkali activated slag cement system is one of the basic researches about the special superplasticizer. In this paper, the surface tension of surfactant-alkali-water was studied by Wilhelmy method. The results showed, first, water-glass had the best efficacity of several alkali activators, when the modulus of water-glass was 1.5 and dosage of water-glass by Na2O was 8%, the surface tension was reduced by 33 mN/m and reduced to 39.9mN/m; second, [CH3(CH2)9]2N(CH3)2Cl had the best efficacity of several surfactants, when the concentration of [CH3(CH2)9]2N(CH3)2Cl was 50g/L, the surface tension was reduced by 35.3 mN/m and reduced to 32.5 mN/m; finally, the effect of surfactant and alkali together on the surface tension of water was complex, surfactants had hardly effective in water glass.

Mixture of the Reaction Products during Hardening of the Water Glass Radiation-Protective Composites

2013 ◽  
Vol 746 ◽  
pp. 289-292 ◽  
Author(s):  
Evgeniy Valerjevich Korolev ◽  
Anna Nikolaevna Grishina
Keyword(s):  
Chemical Composition ◽  
Phase Analysis ◽  
Chemical Reactions ◽  
Water Glass ◽  
Building Materials ◽  
Water Resistance ◽  
Barium Chloride ◽  
Reaction Products ◽  
X Ray

The water glass can be used as a binder for the design of water-resistant radiation-protective building materials. In the present work the possibility of hardening of such materials by barium chloride is investigated. The chemical reactions which can take place during the structure forming and lead to the formation of barium hydrosilicates are presented. It is shown by means of X-ray phase analysis that formation of such hydrosilicates of composition BaO·SiO2·6Н2О, BaO·2SiO2·4Н2О, Ba2[SiO2(OH)2]2and BaO·SiO2·Н2О actually occurs. The influence of the quantity of hardener to the chemical composition of the reaction products is examined. The effect of the reaction products to the water resistance of composite is studied. It is shown that water resistance can be increased in case of stochiometric quantity of barium chloride; in such case the primary product of reaction is BaO·2SiO2·4Н2О.

Effect of Phosphorus or Boron Addition on Water-Resistance of Water-Glass Adhesives

2003 ◽  
Vol 439 ◽  
pp. 215-220
Author(s):  
Hyung Mi Lim ◽  
Bong Young Kim ◽  
Seung Ho Lee
Keyword(s):  
Water Glass ◽  
Water Resistance ◽  
Boron Addition

scholarly journals FORMATION OF ENVIRONMENTAL COMPETENCY OF STUDENTS OF BIOLOGICAL SPECIALTIES IN THE PROCESS OF POLISH PRACTICE

2018 ◽  
pp. 39-43
Author(s):  
L. GOMLYA
Keyword(s):  
Environmental Issues ◽  
Local History ◽  
Practical Application ◽  
Educational Impact ◽  
Domestic Sphere ◽  
Additional Information ◽  
A Value ◽  
Field Practice ◽  
Environmental Motivation ◽  
Educational Field

Organizational-process possibilities of the educational field practice for the purpose of ecological competence forming for the students of biological specialties have been presented in the article. Basic factors which complicate students ecological competence forming, fundamental directions of its formation in the process of organization and realization field practice have been underlined in the article.The content of field practice requires additional information on the methods of environmental monitoring in the environment and on the domestic issues. Particularly relevant is the saturation of field practices with the tasks of applied local history and those that affect the spheres of domestic activities and human impact on the environment. Methods of educational impact on students are also needed. Among the generally positive conditions for the formation of environmental competence of students (the presence of ecological content in the discipline, the possibility of self-realization  during seminars and laboratory classes, the practical application of acquired knowledge in field practice), there are factors that impede the formation of this quality. Among them is the lack of content of the environmental issues of the local rank and the practical absence of information relating to the domestic sphere of the person's activities (complicates the decision-making process and responsibility for the state of the surrounding environment), the prevailing use of educational and educational methods that contradict the norms of environmental behavior (make it impossible to form a value the attitude towards nature, environmental motivation and related activities, suppress the readiness to preserve nature and the responsibility for it with en).

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