One‐step synthesis of in situ nanocarbon‐containing calcium aluminate cement in reducing atmosphere

2019 ◽  
Vol 16 (4) ◽  
pp. 1416-1424 ◽  
Author(s):  
Donghai Ding ◽  
Shoulei Yang ◽  
Guoqing Xiao ◽  
Yun Ren ◽  
Lihua Lv ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Reducing Atmosphere ◽  
One Step ◽  
Aluminate Cement

One-step synthesis of in-situ carbon-containing calcium aluminate cement as binders for refractory castables

2018 ◽  
Vol 44 (13) ◽  
pp. 15378-15384 ◽  
Author(s):  
Guoqing Xiao ◽  
Shoulei Yang ◽  
Donghai Ding ◽  
Yun Ren ◽  
Lihua Lv ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Refractory Castables ◽  
One Step ◽  
Aluminate Cement

scholarly journals Exploiting in-situ solid-state NMR spectroscopy to probe the early stages of hydration of calcium aluminate cement

2019 ◽  
Vol 99 ◽  
pp. 1-6 ◽  
Author(s):  
Colan E. Hughes ◽  
Brant Walkley ◽  
Laura J. Gardner ◽  
Samuel A. Walling ◽  
Susan A. Bernal ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Calcium Aluminate ◽  
Solid State Nmr ◽  
Calcium Aluminate Cement ◽  
Solid State Nmr Spectroscopy ◽  
Early Stages ◽  
Aluminate Cement

scholarly journals High-Temperature Chemical Stability of Cr(III) Oxide Refractories in the Presence of Calcium Aluminate Cement

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6590
Author(s):  
Tengteng Xu ◽  
Yibiao Xu ◽  
Ning Liao ◽  
Yawei Li ◽  
Mithun Nath
Keyword(s):  
Solid Solution ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Solid State Reactions ◽  
Environment Friendly ◽  
Excellent Corrosion Resistance ◽  
Early Strength ◽  
The Stability ◽  
Aluminate Cement

Al2O3-CaO-Cr2O3 castables are used in various furnaces due to excellent corrosion resistance and sufficient early strength, but toxic Cr(VI) generation during service remains a concern. Here, we investigated the relative reactivity of analogous Cr(III) phases such as Cr2O3, (Al1-xCrx)2O3 and in situ Cr(III) solid solution with the calcium aluminate cement under an oxidizing atmosphere at various temperatures. The aim is to comprehend the relative Cr(VI) generation in the low-cement castables (Al2O3-CaO-Cr2O3-O2 system) and achieve an environment-friendly application. The solid-state reactions and Cr(VI) formation were investigated using powder XRD, SEM, and leaching tests. Compared to Cr2O3, the stability of (Al1-xCrx)2O3 against CAC was much higher, which improved gradually with the concentration of Al2O3 in (Al1-xCrx)2O3. The substitution of Cr2O3 with (Al1-xCrx)2O3 in the Al2O3-CaO-Cr2O3 castables could completely inhibit the formation of Cr(VI) compound CaCrO4 at 500–1100 °C and could drastically suppress Ca4Al6CrO16 generation at 900 to 1300 °C. The Cr(VI) reduction amounting up to 98.1% could be achieved by replacing Cr2O3 with (Al1-xCrx)2O3 solid solution. However, in situ stabilized Cr(III) phases as a mixture of (Al1-xCrx)2O3 and Ca(Al12-xCrx)O19 solid solution hardly reveal any reoxidation. Moreover, the CA6 was much more stable than CA and CA2, and it did not participate in any chemical reaction with (Al1-xCrx)2O3 solid solution.

Investigations on the properties of Al2O3–MgO refractory castables bonded by in situ carbon containing calcium aluminate cement

2018 ◽  
Vol 5 (9) ◽  
pp. 095205 ◽  
Author(s):  
Donghai Ding ◽  
Shoulei Yang ◽  
Guoqing Xiao ◽  
Yun Ren ◽  
Lihua Lv ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Refractory Castables ◽  
Aluminate Cement

scholarly journals Physicochemical, Mineralogical, and Mechanical Properties of Calcium Aluminate Cement Concrete Exposed to Elevated Temperatures

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3855
Author(s):  
Amirmohamad Abolhasani ◽  
Bijan Samali ◽  
Fatemeh Aslani
Keyword(s):  
Temperature Rise ◽  
Calcium Aluminate ◽  
Elevated Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Calcium Aluminate Cement ◽  
Cement Concrete ◽  
Sem Images ◽  
Strength Deterioration ◽  
Aluminate Cement

One commonly used cement type for thermal applications is CAC containing 38–40% alumina, although the postheated behavior of this cement subjected to elevated temperature has not been studied yet. Here, through extensive experimentation, the postheated mineralogical and physicochemical features of calcium aluminate cement concrete (CACC) were examined via DTA/TGA, X-ray diffraction (XRD), and scanning electron microscopy (SEM) imaging and the variation in the concrete physical features and the compressive strength deterioration with temperature rise were examined through ultrasonic pulse velocity (UPV) values. In addition, other mechanical features that were addressed were the residual tensile strength and elastic modulus. According to the XRD test results, with the temperature rise, the dehydration of the C3AH6 structure occurred, which, in turn, led to the crystallization of the monocalcium dialuminate (CA2) and alumina (Al2O3) structures. The SEM images indicated specific variations in morphology that corresponded to concrete deterioration due to heat.

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