scholarly journals New Metakaolin-Based Geopolymers with the Addition of Different Types of Waste Stone Powder

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 983
Author(s):  
Ivana Perná ◽  
Martina Novotná ◽  
Daniela Řimnáčová ◽  
Monika Šupová

The search for new alternative raw materials and their subsequent use supports the sustainability of natural resources. This article describes the use of waste stone powder (WSP) in geopolymer synthesis. Five different types of WSP (feldspar, limestone, marlstone, dolomite, marble) were comprehensively characterized and their influence on the resulting properties (especially mechanical and textural properties, setting time and structure) of metakaolin-based geopolymer composites was investigated. Their comparison with a geopolymer composite containing only quartz sand has revealed that WSP additions have a small but positive effect on the mechanical or textural properties of geopolymers. Moreover, setting time measurements have shown that waste stone powders can be used as an accelerator of geopolymer reaction solidification. The results demonstrated that the mentioned types of WSP, previously landfilled, can be used for the preparation of geopolymers. This can help reduce the environmental burden.

2013 ◽  
Vol 772 ◽  
pp. 156-160
Author(s):  
Yan Long Liu ◽  
Chao Fa Tang ◽  
Wen Hao Shen ◽  
Ji Wen Han ◽  
Hong Shuang Du

The fiber of the agriculture and forestry biomass resources and the processing residues is main raw materials as a reinforcing material, the calcinated calcium sulfate hemihydrates by industrial flue gas desulfurization waste is a binder, adding efficient composite retarder to increase the initial setting time of gypsum and meet the production process requirements, adding conductive carbon black to reduce system resistance gypsum fiber to produce and meet the requirements of antistatic products. By semi-dry process, we produced the retardant, waterproof, environmental friendly and anti-static desulfurization gypsum fiberboard. Desulfurization gypsum antistatic fiberboard can meet the market demand for functional products used widely in antistatic floor, antistatic wall panel etc. The production of anti-static desulfhurization gypsum fiberboard expands the application range of desulfhurization gypsum, at the same time, which changes the structure of the forestry industry and has a positive effect on improving the forestry economic operation quality, efficiency and international competitiveness.


2018 ◽  
Vol 35 ◽  
pp. 160-177
Author(s):  
Janīna Sētiņa ◽  
Gundars Mežinskis ◽  
Vasilijs Akišins ◽  
Laila Pētersone ◽  
Inna Juhņeviča ◽  
...  

Pētītas iespējas izmantot jaunas izejvielas stikla šķiedras ražošanā, īpašu uzmanību pievēršot Latvijas minerālām izejvielām – devona (Bāles atradne) un juras perioda (Skudras atradne un Pīlādžu atradne) kvarca smiltīm. Apstrādājot ūdenī Skudras atradnes kvarca smiltis, krāsojošo oksīdu daudzums samazināts līdz 0,066 %. Iegūto stiklu īpašību pārbaude parādīja attīrīto Skudru atradnes kvarca smilšu izmantošanas perspektīvu E-tipa stikla šķiedras ražošanā. Veikta arī citu šihtas izejvielu izpēte: kolemanīta, kianīta, kaļķakmens.Pielietojot augstas izšķiršanas spējas skenējošo elektronu mikroskopu, diagnosticēti stikla šķiedras defektu rašanās iemesli un izzināta to novēršanas iespēja.Study of Mineral Raw Materials and Defects in Glass FibresLatvian Devonian period sand from deposit Bāle and Jurassic period sand from deposit Skudra were studied, treated and compared with sand from existing Lithuanian supplier. Investigations of Latvian quartz sand showed that sand is characterized by surface impurities, which are easy to separate combining milling and water purification. These investigations and experimental glass melts using different types of sand confirmed that it is possible to use Latvian refined sand in glass industry.Other glass raw materials – colemanite, kyanite, kaolin, limestone – also have been examined.Glass fibre breakage points were studied using SEM, FTIR and X-Ray diffractions methods. Main reasons of glass fibre breakage are non-homogeneous glass and crystalline or gaseous inclusions coming from corrosion of refractory material. This article is result of the cooperation between Institute of Silicate Materials of Riga Technical University and JSC Valmieras stikla šķiedra.Keywords – glass, glass fibre, raw materials for glass, refined sand, glass defects


2021 ◽  
Author(s):  
Petrica Vizureanu ◽  
Dumitru Doru Burduhos Nergis ◽  
Andrei Victor Sandu ◽  
Diana Petronela Burduhos Nergis ◽  
Madalina Simona Baltatu

Mine tailings are waste materials that resulted from the extraction and processing of raw materials to form mineral products. These dusty particles present negative environmental effects after being deposited in different types of dumping areas. Based on the circular economy concepts and the presently pushing need of identifying wastes as a potential replacement for natural resources, this chapter aims to present the physical (density, microstructure) and mechanical (compressive strength, flexural strength) characteristics of different types of geopolymers which use mine tailings as precursors or blended systems (mixes of different raw materials). The main reasons of approaching this topic are the need to decrease the consumption of natural resources, reduce environmental pollution and create an economic system aimed to capitalize the mining wastes. Accordingly, this chapter includes information regarding the availability of this waste and its potential utilization as a raw material in civil engineering applications. Therefore, reports of specific agencies and multiple research studies which approach tailing based geopolymers or blended systems have been summarized.


2018 ◽  
Vol 7 (4.20) ◽  
pp. 334
Author(s):  
Tumadhir Merawi Borhan ◽  
Munaf A. Al-Ramahee ◽  
Noor Al-Hassnawi ◽  
Zaid Ali AlZaidi

The effect of retarding admixture on the fresh and hardened behaviour of different types of cement mortars and pastes when using a retarding admixture was investigated in this study. The types of cement used are; White cement (WhC), Ordinary Portland cement (OPC) and Sulphate Resistant Portland cement (SRC). Different cement mortar and paste mixes were cast, for this purpose, with and without the admixture. Initial and final setting times, compressive strength, length change, absorption and density for these mixes were examined at the curing ages of 3,7,28,45 days. The results showed that the addition of retarding admixture delayed the setting time significantly of WhC paste. The retarding admixture has a positive effect on the compressive strength of the mortar specimens for all types of cement used. regarding the length change test, the admixture was found to reduce the initial expansion for all types of cement at all ages. The results also showed an increase in the density and decrease in water absorption, especially at the later ages for all types of cement.  Among all cement types used, WhC was noticeably the most affected type by using the retarding admixture compared to other types of cement used.  


2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.


2019 ◽  
Vol 39 (2) ◽  
pp. 196-205
Author(s):  
N. V. Firov

A comparative analysis of the prices of raw materials, fuel, electricity in Russia and Western countries, the dynamics of their growth and impact on the national economy. It is shown that in the interests of the country's economic development and improving the welfare of the population, it is necessary to use its natural resources more effectively, to pursue a more stringent and at the same time balanced policy to curb the growth of prices, taking into account the interests of the state and business.


Author(s):  
Mahesh K. Joshi ◽  
J.R. Klein

The twenty-first century is being touted as the Asian century. With its stable economy, good governance, education system, and above all the abundant natural resources, will Australia to take its place in the global economy by becoming more entrepreneurial and accelerating its rate of growth, or will it get infected with the so-called Dutch disease? It has been successful in managing trade ties with fast-developing economies like China and India as well as developed countries like the United States. It has participated in the growth of China by providing iron ore and coal. Because it is a low-risk country, it has enabled inflow of large foreign capital investments. A lot will depend on its capability and willingness to invest the capital available in entrepreneurial ventures, its ability to capture the full value chain of natural resources, and to export the finished products instead of raw materials, while building a robust manufacturing sector.


2021 ◽  
pp. 002199832110316
Author(s):  
Nuno Gama ◽  
B Godinho ◽  
Ana Barros-Timmons ◽  
Artur Ferreira

In this study polyurethane (PU) residues were mixed with residues of textile fibers (cotton, wool and synthetic fibers up to 70 wt/wt) to produce 100% recycled composites. In addition, the effect of the type of fiber on the performance of the ensuing composites was evaluated. The presence of fibers showed similar effect on the density, reducing the density in the 5.5-9.0% range. In a similar manner, the addition of fillers decreased their thermal conductivity. The 70 wt/wt wool composite presented 38.1% lower thermal conductivity when compared to the neat matrix, a reduction that was similar for the other type of fibers. Moreover, the presence of fillers yields stiffer materials, especially in the case of the Wool based composites, which with 70 wt/wt of filler content increased the tensile modulus of the ensuing material 3.4 times. This was attributed to the aspect ratio and stiffness of this type of fiber. Finally, the high-water absorption and lower thermal stability observed, especially in the case of the natural fibers, was associated with the hydrophilic nature of fibers and porosity of composites. Overall, the results suggest that these textile-based composites are suitable for construction and automotive applications, with the advantage of being produced from 100% recycled raw-materials, without compromised performance.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1242
Author(s):  
Katarzyna Świąder ◽  
Anna Florowska ◽  
Zuzanna Konisiewicz

Set type yoghurts are characterised by a semi-solid texture, which is created during the fermentation process. The tea infusion in this type of yoghurt production can influence the quality of the final product. Therefore, the aim of the experiment was to evaluate the influence of the addition of 3, 6 and 9% inulin to oolong tea-infused yoghurts on the sensory quality. It has been evaluated by trained experts using a Quantitative Descriptive Profile analysis and by consumers using hedonic scaling, as well as on instrumentally evaluated features such as texture, stability and visual parameters. The addition of oolong tea to yoghurt resulted in positive changes in the perception of sweet, peach and nectar odours and flavours, and also creaminess, as well as negative changes in the presence of a bitter taste, the whey presence and a colour intensification towards dark cream (p ≤ 0.05). The addition of inulin to the tested oolong tea yogurts caused a decrease in the whey presence and brightened the yoghurt’s colour (6% and 9%, p ≤ 0.05, respectively), as well as an improved creaminess and an increase in the sweet taste of the yoghurt. It was also observed that the addition of oolong tea deteriorated the instrumentally evaluated texture of the set yoghurts, while inulin at a higher concentration (9%, p ≤ 0.05) increased the firmness and adhesiveness. Moreover, the addition of inulin also had a positive effect on the yoghurt’s stability. The addition of inulin to oolong tea-infused set yoghurts may be valuable both as a source of prebiotic fibre in functional products and as a factor improving the quality of these products.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.


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