The Through-Dyed Autoclaved Silicate Concretes with the Use of Thermally Activated Iron Ore Raw Materials Refinement Tailings

2018 ◽  
Vol 284 ◽  
pp. 1101-1106
Author(s):  
Irina V. Starostina

The iron ore raw materials refinement waste is not virtually used after the wet magnetic separation and is accumulated in special hydraulic constructions – tailing dumps. This work considers the opportunity of using the heat-treated tailings as loading pigments for through-dyed autoclaved silicate concretes production. The heat-treated tailings were added to the raw mix instead of quartz sand. The concrete samples of light-pink shades of color were obtained. It has been demonstrated that the activation processes, taking place at heat treatment of tailings, as well as the influence of iron oxides acting as a mineralizer at high temperatures, create the increased imperfection of the quartz component’s structure. This increases the synthesis rate of new formations – the low-basic calcium silicate hydrates – and increases the strength properties of the samples with optimal compositions by 70-75% as compared to the control sample.

1956 ◽  
Vol 60 (551) ◽  
pp. 739-748 ◽  
Author(s):  
W. Deck

In Switzerland aircraft often have to take off and land in narrow mountain valleys where a strong, irregular wind is blowing. In these circumstances one faulty casting may cause failure of a control; or a small part, if insufficiently heat-treated, may fracture and result in the loss of the aircraft. For this reason, thorough inspection during production and careful maintenance of the aircraft are of prime importance. Control within the aircraft factory consists of inspection of the raw materials, such as bars, sheet metal, tubes, castings, forgings and so on; testing of the most important parts during manufacture to detect cracks and to control the heat treatment; and the final control of all parts, of components and of the whole aircraft. Maintenance inspection reveals cracks, corrosion and other defects of the most important parts of the aircraft.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 863 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang ◽  
Jing Wang ◽  
Xuehua Wang

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.


Polimery ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 357-361
Author(s):  
Bogdan Kozik ◽  
Mariusz Dębski ◽  
Piotr Bąk ◽  
Małgorzata Gontarz ◽  
Małgorzata Zaborniak

The article presents the results of strength tests in the form of a static tensile test on the INSTRON 5967 testing machine. Samples were made with the use of the Prusa i3 MK3 3D printer, by modeling with a plasticized material (FFF) made of ABS copolymer, polylactide and its modified variant. According to the information provided by the manufacturer, heat-treated modified polylactide has mechanical properties similar to ABS copolymer filament. The publication also discusses the method of manufacturing elements subjected to the tests, the heat treatment process, as well as changes in material properties as a result of this treatment. Based on the test results, it was found that the annealing process increased the proportion of the crystalline phase, which significantly improved the strength properties of the modified polylactide.


2017 ◽  
Vol 748 ◽  
pp. 12-16
Author(s):  
Xiao Zhen Liu ◽  
Yu Fan Ni ◽  
Xiao Zhou Liu ◽  
Le Tian Xia ◽  
Jie Chen ◽  
...  

The cerium dioxide films were prepared with cerium foils as raw materials by anodization in Na2C2O4-NH3∙H2O-H2O-(CH2OH)2 electrolyte. The anodic cerium oxide films were heat treated in 100~400°C and 0.5~2.5h, respectively. The heat treated anodic cerium oxide films were characterized with X-ray diffraction (XRD). The heat treated anodic cerium oxide film at 100°C is semi crystalline film. The heat treated anodic cerium oxide film at 200°C, 300°C, 350°C, 400°C, respectively for 2h, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment temperature in 200 ~ 400 °C. The heat treated anodic cerium oxide film at 400°C for 0.5h, 1h, 1.5h, 2.5h, respectively, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment times in 0.5h ~ 2.5h.


2012 ◽  
Vol 66 (1) ◽  
pp. 53-57
Author(s):  
Dragan Palic ◽  
Liesl Morey ◽  
Kedibone Modika ◽  
Bojana Kokic ◽  
Olivera Djuragic ◽  
...  

Some of feedstuffs used as raw materials in feed industry contain anti-nutritional factors that negatively influence their quality. One of them is soybean, which is, prior to oil extraction, referred to as full-fat soybean (FFSB). Anti-nutritional factors in raw FFSB can be destroyed by moderate heating, but both over- and under heat processing limits the availability of soybean amino acids. Among laboratory procedures that are available for assessing the degree of FFSB heat treatment, two methods, i.e. Protein dispersibility index (PDI) and protein solubility in potassium hydroxide (PSKOH), are based on protein solubility, which was claimed to be the most reliable indicator of the degree of FFSB heat treatment. This paper presents the results of an inter-laboratory study conducted to establish precision of the PDI and PSKOH methods by determining their reproducibility limits. Five samples of FFSB were heat-treated at temperatures between 110 and 164 ?C and analyzed by six laboratories for PDI and PSKOH. Established reproducibility limit for PDI method of 8.87 index units found in this study appeared to be too wide, indicating a low precision of this method. PSKOH method produced very good reproducibility limit of 8.56% and could be recommended as a preferred method for FFSB quality control in feed laboratories.


2021 ◽  
Vol 71 (343) ◽  
pp. e251
Author(s):  
B.A. Feijoo ◽  
J.I. Tobón ◽  
O.J. Restrepo-Baena

The substitution of the normalized aggregate by residual foundry sand (WFS) was studied on the physical properties of mortars by means of resistance to compression and capillary absorption tests. The aggregate was replaced by WFS in its natural state (WFS), washed residual foundry sand (WFSW) and heat treated residual foundry sand (WFST). The WFS had a percentage of bentonite, which was sought to be thermally activated. It was found that the physical behavior of the mortars containing WFS and WFSW was similar to that of the control sample. The clay recovered from the sand washing was evaluated for its pozzolanic potential, it was found that, with the thermal treatment, the montmorillonite acquires pozzolanic behavior. Mortars with WFST presented a drop in compressive strength. The pozzolanic effect achieved in the clay was not reflected in the compressive strength of the mortars with WFST.


Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Paulo Ivan Andrade ◽  
Solange de Oliveira Araújo ◽  
Duarte Miranda Neiva ◽  
Benedito Rocha Vital ◽  
Angélica de Cássia Oliveira Carneiro ◽  
...  

Abstract Wood-based panels made of waste and recycled raw material are lacking of dimensional stability. The aim of this study is to evaluate the potential beneficial effect of heat treatment (HT) on the properties of particleboards produced from waste of Pinus sp. used for packaging. The wood particles were heat treated at 180°C, 200°C and 220°C after grinding, and panels were produced with incorporation of 25%, 50%, 75% and 100% HT particles. The materials served as reference were particles without HT. Mass loss at 180°C and 200°C was small but increased significantly to 10.6% at 220°C. The HT caused a partial degradation of hemicelluloses, thereby the relative lignin content increased from 29.7% to 37.8% for the HT220°C samples. Thermogravimetry revealed higher thermal stability of the HT particles. The equilibrium moisture content decreased with HT, e.g. panels with HT220°C showed 30% lower compared to the reference. Swelling of the panels was lowered by 30% (panel with 75% HT material) compared to the reference. The results with HT pine were successful in terms of dimensional stability and lower hygroscopicity; however, the panels lost some strength properties.


2010 ◽  
Vol 658 ◽  
pp. 89-92 ◽  
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Hai Bo Yang ◽  
Fen Wang

Ti2AlC/Al2O3 nanocomposites were synthesized by high energy milling with Ti, C, Al and TiO2 as initial materials. The formation and evolution of phases in high energy milling and following heat treatment were investigated by X-ray diffractometer (XRD). The results show that the raw materials of Ti, C, Al and TiO2 were pulverized to ultrafine particles, and some of them transformed to amorphous phase. When the as-milled powders were heat treated in vacuum atmosphere, TiC was firstly produced and released large amount of reactive heat, which resulted in the reaction between Ti and Al to produce intermediate phases of the TixAly (TiAl3, TiAl, and Ti3Al) intermetallics. The reaction between Al and TiO2 produced Al2O3 phase. The TixAly intermetallics and the residual Ti and Al transformed to TiAl equilibrium phase. Finally, the TiAl intermetallics and the TiC reacted to yield Ti2AlC, which produced Ti2AlC/Al2O3 nanocomposite together with the former in-situ formed Al2O3.


2015 ◽  
Vol 659 ◽  
pp. 194-198 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Suwipa Poosrisoma ◽  
Parida Jampeerung ◽  
Tepiwan Jitwatcharakomol

The redox reaction of a tableware soda-lime silicate glass contained with 0.04 - 1.00 wt% of iron oxide is investigated by UV-Vis spectroscopy. The quality and purity of raw materials, especially sand is required to control the amount of iron oxide as low as possible. Normally tableware glass contains small amount of iron oxide (0.01 - 0.04 wt%) and iron effect (green color) is controlled by adding decolorizing agent. The heat treatment around transition temperature is another method to decolorize iron by redox reaction control. It is believed that the reaction of iron oxide Fe2+(green) « Fe3+(yellow) still occurs in annealing process. In this study, the glasses were prepared by melting in the platinum crucibles. After annealing, they are cut into four pieces and heated at 550 560 570 and 580°C with different times. The results of the transmittance showed no significantly change but the color in CIE L*a*b* system of glasses heat treated at 550 and 560 °C slightly change into whiter shade. According to the result of calculated Fe2+/Fe3+ ratio, the ratio of these glasses were decreased by 5 and 2.5 % respectively. On the contrary, the redox ratio of glass heated at 580 °C increased, due to Fe3+to Fe2+ and the color changed into green. The results proved the kinetic of the redox reaction of Fe2O3 and the possibility to use annealing process as another tool to control flint color of glass.


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