scholarly journals Minerālo izejvielu pielietošanas un stikla šķiedras defektu izpēte

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 ◽  
Vol 903 ◽  
pp. 197-202
Author(s):  
Ruta Švinka ◽  
Visvaldis Švinka ◽  
Maris Rundans ◽  
Inta Timma ◽  
Laila Petersone

Clay of the deposit Liepa is used for the production of ceramic building and finishing bricks in the factory “Lode” in Latvia. In the present work different types of these clays were investigated and “quartz effect” was determined using quartz sand as a leaning material. The substitution of quartz sand with milled E-glass fibre from Valmiera Glass was investigated and the changes in the magnitude of the quartz inversion effect were analysed. Thermal expansion was the main method for the determination of possible formation of cracks during technological process. Powder of milled glass fibre in amount of 5–10 % affects such properties as water uptake, porosity and apparent density and provides the required material properties at a lower firing temperature.


2012 ◽  
Vol 730-732 ◽  
pp. 592-597
Author(s):  
Célia Sousa ◽  
Fernando Castro ◽  
Cândida Vilarinho ◽  
Delfim Soares

Among the solid wastes produced by textile industry, there is a significant amount of wastes with energetic value and which are usually sent to controlled landfills, without any recovery. This traditional route corresponds to high economical and environmental costs, since wastes can be used as a source of energy and/or materials. With the recycling route strongly restricted due to the presence of mixtures of different types of polymeric compounds, some of them not biodegradable, the study of the feasibility of energy recovery from such wastes is of upmost importance and the aim of the present work. Most of the wastes are valuable resources that can be used as raw materials or as an energy source to produce heat or electricity. In this work the potentiality of energy recovery from solid wastes of some of the Vale do Ave textile units was investigated. For that purpose, wastes have been characterized for their weight loss at 105°C, calorific value and ashes content (after burning out at 850°C). The chemical composition of the ashes was determined by X-Ray fluorescence spectrometry. DSC-TGA tests were performed in two different atmospheres, air and argon, in order to evaluate the thermal behavior of the studied wastes. The characterized wastes showed calorific values not negligible, varying from 3500 to10400 kcal/kg (at dry base), similar to the results obtained by others authors and comparable to solid materials which are traditionally considered as fuels (sugar cane, lignite, etc). A weight loss at (105°C) lower than 6.5% and a maximum ashes content of 15% was achieved. However, some ashes present high contents of heavy metals, which can drives to environmental concerns. By the analysis of the thermal profiles it was found that wastes decomposition takes place at low temperatures (< 600°C) resulting in a small amount of the final solid fraction. Concerning the obtained results, the solid wastes collected from different textile units show high potential for energy recovery.


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.


2021 ◽  
Vol 3 (6 (111)) ◽  
pp. 32-40
Author(s):  
Eko Sulistiyono ◽  
Murni Handayani ◽  
Agus Budi Prasetyo ◽  
Januar Irawan ◽  
Eni Febriana ◽  
...  

Indonesia has very abundant reserves of silica, but progressive studies on the deposition of this material are very few, resulting in limited applications of silica. This work refers to the purification of silica from quartz sand originated from Sukabumi, Indonesia to obtain high-purity silica, which can be applied as important raw materials for special purposes. The aim of our research is to improve low-grade silica from quartz sand by removing impurities, especially aluminum and iron removal, using sulfuric acid leaching. In order to achieve the aim, the effect of reaction time and sulfuric acid concentration on the leaching process was investigated. The effectiveness of sulfuric acid for the impurities removal was observed. The chemical composition of the samples before and after leaching was studied using X-ray fluorescence. The mineralogical analysis of the starting materials and the products was conducted using X-ray diffraction. Microstructure analysis was performed using a scanning electron microscope, and EDS test was used to show the element composition at different points. The experimental results show that the optimum condition of the leaching process occurs at a reaction time of 5 hours with a sulfuric acid concentration of 10 N. The silica levels increase from 93.702 % to 96.438 %. Aluminum and iron impurities reduced from 4.691 % to 2.712 % and from 0.641 % to 0.094 %, respectively. At this optimum point, sulfuric acid is very effective to remove aluminum and iron impurities up to 42 % and 85 %, respectively. The results of this research can be a very significant opportunity to increase the value added of quartz sand from Sukabumi, which can enhance the quality of low-grade silica to provide better raw materials for glass industries.


Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 851
Author(s):  
Tatiana Aleksandrova ◽  
Nadezhda Nikolaeva ◽  
Anastasia Afanasova ◽  
Artyem Romashev ◽  
Valentin Kuznetsov

Deterioration of mineralogical and physical characteristics of mineral raw materials results in the formation of the primary task for the comminution processes—reduction in the size of ore to obtain a material with a certain granulometric composition, which in turn is achieved by overgrinding of raw materials and, consequently, an increase in energy costs. The work aimed to justify the possibility of selective disintegration of mineral assemblages of polymetallic ores of various genesis at the stage of crushing based on in-depth investigation and revealing of interrelation and mutual influence of mineralogical-geochemical features, textural-structural and technological properties. Structural and textural features have been studied by the methods of computed X-ray microtomography. Experimental and theoretical investigations of mineralogical and technological parameters of raw materials, as well as research on crushing using different types of crushers, made it possible to substantiate the possibility of selective disintegration for polymetallic ores.


2011 ◽  
Vol 99-100 ◽  
pp. 1361-1364
Author(s):  
Zhen Wu Shi ◽  
Nian Suo Xie

The short mullite fibers were manufactured by andalusite mineral raw materials of Mei County China through isothermal sintering process between 1350°C and 1550°C under the oxidation atmosphere. And then the process which andalusite mineral raw materials of Mei County China had transformed into short mullite fibers was analyzed by X-ray automatic powder diffractometer D/MAX-2400, and the property of morphology of short mullite fibers was observed by scanning electronic microscope QUNATA200. The result manifests that in the range of experimental temperature, andalusite mineral raw materials of Mei County China fully transforms into mullite phase after the specimen is kept warm for 3 hours under sintered temperature 1450°C, and the mullite phases which are transformed at sintered temperature 1450°C mostly present in the form of short fiber while the temperature naturally cools to room temperature with furnace, and this kind of short mullite fiber has the best crystallinity, and the least structural defect and the highest length to diameter ratio.


2010 ◽  
Vol 74 (4) ◽  
pp. 747-771 ◽  
Author(s):  
C. Rathossi ◽  
P. Tsolis-Katagas ◽  
C. Katagas

AbstractA ‘metamorphic vermiculite’-like phase was identified in Ca-rich ancient ceramic sherds from excavations in NW Peloponnese, Greece. Archaeometric investigations have shown that the raw materials used in the production of ancient ceramics were derived from local Plio-Pleistocene sediments. Analysis by X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy showed that ‘metamorphic vermiculite’ is a common constituent phase of these sediments occurring in three texturally different types: as interstratified white mica-chlorite and chlorite-vermiculite, and white mica-(white mica-chlorite) stacks. In an attempt to elucidate the thermal transformation of ‘metamorphic vermiculite’ present in the calcareous raw materials, we produced experimental ceramics made from these local raw materials and fired them at 700, 750, 850, 950 and 1050°C in a static air furnace. The mixed-layered chlorite-vermiculite was transformed completely at ∼800°C contributing to the formation of new high-Tminerals. The two other types of ‘metamorphic vermiculite’ retain their original lath-like shape up to 1050°C and only a few crystals show that they have undergone complete transformation at this temperature. In the latter crystals, numerous nanocrystals were formed sub-parallel to the former cleavages of ‘metamorphic vermiculite’ pseudomorphs, suggesting their contribution to the nucleation of high-Tminerals (i.e. ferrian aluminian diopside, spinel, Fe oxides) by reactions with the available CaO. It is suggested that the firing conditions (i.e. maximum reaction temperature of 1050°C, reaction time of 1 h, oxygen atmosphere) which promote disequilibrium reactions, and the greater contribution of the white mica constituent against chlorite in some of the initial structures of ‘metamorphic vermiculite’ may be responsible for the delay of its thermal decomposition at 1050°C.


Author(s):  
A. K. Koizhanova ◽  
◽  
G. V. Sedelnikova ◽  
M. B. Erdenova ◽  
A. N. Berkinbaeva ◽  
...  

The article contains the results of the studies performed for the biochemical eхtraction modes for mineral raw materials using thionic bacteria Acidithiobacillusferrooxidans of a certain strain capable to oxidize sulfide minerals. A representative sample of mineral raw materials was taken, and its physical and chemical studies were performed. The optimal conditions to leach mineral raw materials with biochemical solvents based on various factors (temperature, S:W) were established. Modern physical and chemical methods of analysis were used during the study: X-ray fluorescence, X-ray phase, mineralogical, electron probe, chemical analyzes, IR methods to study the phase composition of ores and changes in the structure of minerals. The chemical composition of the ore sample quartered and crushed up to a size of -0.074 mm is as follows, wt. %: SiO2 - 60.11; Al2O3 6.2; Zn 0.016; Cu 0.10; Fe - 2.5; S 0.50; Au - 3.67 g/t and Ag - 3.2 g/t. This paper discusses various options for agitational leaching with acid pre-wash, bacterial dissection and oxidative decomposition of minerals using sodium hypochlorite. The results obtained showed that the most effective method to increase the gold recovery is to perform bacterial oxidation of ore using acidophilic bacteria At. Ferrooxidans preliminarily adapted to the material composition of the test sample, followed by treatment with sodium hypochlorite solution and cyanidation. Biohydrometallurgical ore processing provides high gold recovery (78.1%).


2020 ◽  
Vol 11 (7-2020) ◽  
pp. 92-97
Author(s):  
Aleksandr S. Potokin ◽  
◽  
Andrei A. Klimov ◽  

Electric pulse destruction of certain types of mineral raw materials has a number of advantages over mechanical methods of destruction, for example, selectivity of destruction without damaging the crystal structures of the destroyed raw materials; lower energy intensity of the processes of destruction of hard rocks: no additional contamination of materials when crushing especially hard and abrasive materials. Comparative analysis of the results of destruction of various types of rocks allows us to conclude about the advantages or disadvantages of electric pulse destruction of certain rocks.


Author(s):  
K. A. Brookes ◽  
D. Finbow ◽  
Madeleine Samuel

Investigation of the particulate matter contained in the water sample, revealed the presence of a number of different types and certain of these were selected for analysis.An A.E.I. Corinth electron microscope was modified to accept a Kevex Si (Li) detector. To allow for existing instruments to be readily modified, this was kept to a minimum. An additional port is machined in the specimen region to accept the detector, with the liquid nitrogen cooling dewar conveniently housed in the left hand cupboard adjacent to the microscope column. Since background radiation leads to loss in the sensitivity of the instrument, great care has been taken to reduce this effect by screening and manufacturing components that are near the specimen from material of low atomic number. To change from normal transmission imaging to X-ray analysis, the special 4-position specimen rod is inserted through the normal specimen airlock.


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