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More generally, the research deepens researchers' understanding of thermal transport in a class of materials known as phase-change materials. What Tian and her team of …
3. Iron-rich bauxite processing and metallurgy. Iron-rich bauxite ore usually contains over 40 wt% iron oxide [11, 12], huge reserves are found in Australia, Guinea, Brazil, Laos, Vietnam and China, but they have not yet been used effectively.It is worth noting that more than 1.5 billion tons of iron-rich bauxite resources have been explored over the last 20 years …
Thermal transport in ice features an unusual response. In addition to its intrinsic scientific interest, an understanding of the mechanisms determining the thermal conductivity of ice might be relevant in climate modelling and planetary science. Accurate microscopic models can provide important molecular ins 2018 PCCP HOT Articles
A low lattice thermal conductivity of 0.56 W/mK was obtained for MnTe 0.92 Se 0.08, which is quite close to the amorphous limits. A detailed Debye model analysis reveals the underlying mechanism of phonon scattering and well predicts the thermal conductivity with different contents of Se. Meanwhile, a slight increase of carrier concentration ...
DOI: 10.1016/J.CERAMINT.2018.07.132 Corpus ID: 139987474; Abrasion resistance and thermal conductivity of ZrO2-containing bauxite refractories in the transition zone of a cement kiln
Highly anisotropic Si3N4 ceramics were successfully fabricated by tape-casting of raw α–Si3N4 powders with β–Si3N4 single-crystal particles as seed particles and Y2O3 as an effective sintering aid, followed by hot isostatic pressing at a temperature of 2773 K for 2 h under a nitrogen gas pressure of 200 MPa. The microstructure consists of very large elongated …
Compared with 650 and 700 °C, the pre-desilication results of low-grade bauxite after thermal activation at 600 °C had a significant improvement. Only after 30 min of leaching, the ratio of alumina to silica of low-grade bauxite can be increased from 2.39 to 6.78. This study may have a certain significance for selecting a suitable thermal ...
The results showed that the bricks made with the addition of 30% of bauxite waste presented the lowest values of thermal conductivity and a compression mechanical strength …
Thermal insulation composites were developed by utilizing bauxite residue. • Composites display superior thermal insulation properties. • Composites show low thermal diffusivity (0.161 m m 2 / s) and low water retention <0.15 %.. Bauxite residue has great positive effect on the thermal stability of the composite.
Study on the thermal conductivity of silicon nitride ceramics with magnesia and yttria as sintering additives. Materials Letters, Vol. 57, Issue. 1, p. 15. CrossRef; Google Scholar; Yokota, Hiroshi and Ibukiyama, Masahiro 2003. Effect of lattice impurities on the thermal conductivity of β-Si3N4. Journal of the European Ceramic Society, Vol. 23 ...
The thermal conductivity was found to be 7.6 W m−1 K−1 at the near wall compared to the bulk values of 0.22 W m−1 K−1. The decrease in porosity near the wall is not enough to account for …
Effect of thermal activation and particle size on cementitious activity of bauxite tailings Zhou, Longfei; Gou, Mifeng; Hou, Wenli; Zhao, Mengke; Zhao, Jinhui ...
To substitute bauxite-SiC refractories which are currently used in transition zone of cement kilns, this paper aims to fabricate novel working lining with lower thermal conductivity and outstanding abrasion resistance.For this purpose, a composite refractory material, based on the incorporation of zircon and fused zirconia-mullite (FZM) into bauxite-based refractories is …
The Bauxite residue was collected from one of Hindalco's repository locations inside the aluminium refinery in Belgaum, India. Table 1 displays the chemical composition of the materials used as an aluminosilicate source based on the XRF (X-ray fluorescence spectroscopy) analysis. The moisture level in the raw Bauxite residue resulted in a 4.9 % loss of ignition hindering its …
The results showed that there was a great effect of content of SiC on bulk density, thermal expansion coefficient and thermal shock resistance of mullite-bauxite castable. Under the experimental ...
Measured and computed thermal bulk conductivity for quartz flint (d p,mean =2.0 mm) and sintered bauxite (d p,mean =0.6 mm). Since the model provides reliable results, it is …
The thermal evolution of bauxite-derived red mud was studied in this work by different complementary techniques. Dried red mud is substantially inert up to 900°C, the loss of H 2 O from aluminium hydroxides and of CO 2 from silico-alumino-carbonates being the only detectable effects. At 900°C red mud is dark red in colour.
Keywords Bauxite tailings · Particle size · Thermal activation · Cementitious activity Introduction The world is extremely abundant in bauxite resources, but most of the bauxite has a relatively low Al/Si ratio. Before using Bayer process to produce alumina, it is necessary to adopt a desilication treatment to improve the aluminum–sili -
to treat bauxite ores which have high silica content (i.e., SiO 2 ˃ 7%), low alumina to silicate rate, high caustic soda con-sumption, high silica formation, large quantities of bauxite residue, and storage problems of red mud [6–9]. DuringandafterWorldWarII,severalresourcesotherthan bauxite have been largely expected. The United States
Thermal diffusivity values of 40/70 sintered bauxite are lacking in the literature; however, a pellet of sintered bauxite has been reported to have a thermal diffusivity of 2.8 mm 2 s –1 at room temperature and a thermal …
The present work shows the results of X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermal analysis of untreated (RM nt) and acid-treated red mud (RM a), a bauxite ore-processing waste, exchanged with Pb 2+, Cd 2+, and Zn 2+ cations. These studies were performed in order to investigate the changes in the sorbent structure caused by the …
The thermal conductivity value is linearly dependent on the temperature, which can be well fitted as follows: (3) k = m T, where k (in W / (m ∙ K)) represents the thermal …
The chemical composition of low-grade bauxite had a specific change after thermal activation according to Table 2.Although the content of other components changed slightly, the contents of Al 2 O 3 and SiO 2 were increased while LOI had a significant decrease. The reason may be that some minerals containing alumina and silica lose their bound water.
sludg layer icknessof 0.0125 m, wer used etermin th thermal nductivity of sludge while si formula (1). I w observed h h averag valu thereof uring
Covers the basic understanding of thermal conduction mechanisms in various high thermal conductivity materials including diamond, cubic boron nitride, and also the latest material like carbon nanotubes. Intended as a good reference book for scientists and engineers involved in addressing thermal management issues in a broad spectrum of industries
Characteristic samples from the No. 1 ore body of the Jinlong bauxite deposit in Guangxi Province, China, were assessed to determine their chemical composition using whole-rock geochemical analysis, their mineral components using X-ray diffraction, their thermal characteristics via differential thermal analysis, thermogravimetry and differential …
Preparation and Performance Study on Ferric-Rich Bauxite-Tailings-Based Thermal Storage Ceramics. XRDs were conducted on bauxite-tailing-based ceramic materials. Figure 6 a shows the XRD phase analysis of ceramic materials at different sintering temperatures with a Fe 2 O 3 content of 30 wt%. It can be observed in the figure that the main ...
Fundamentally, understanding the origins of HTC remains a challenge. The conventionally accepted criteria for HTC materials are (i) small average atomic mass (M ¯); (ii) strong interatomic bonding; (iii) simple crystal structure; and …
Although the thermal conductivity of liquid water is well established, many conflicting values for the thermal conductivity of ice have been reported in the literature. This work demonstrates that the significant differences in the reported ice thermal conductivities can be attributed to differences in the freezing conditions and measurement ...
