Leaching kinetics of Cr(VI) phases in the matrices of calcium aluminate cement-bonded refractory castables: Role of micro-silica

2020 ◽  
Vol 40 (15) ◽  
pp. 6123-6131 ◽  
Author(s):  
Shengqiang Song ◽  
Wenke Zhang ◽  
Mithun Nath ◽  
Pin-Wen Guan ◽  
Zhengliang Xue ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Leaching Kinetics ◽  
Refractory Castables ◽  
Micro Silica ◽  
Kinetics Of ◽  
Aluminate Cement

Role of Cement Type on Carbonation Attack

2002 ◽  
Vol 17 (7) ◽  
pp. 1834-1842 ◽  
Author(s):  
S. Goñi ◽  
M. T. Gaztañaga ◽  
A. Guerrero
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Alkali Content ◽  
X Ray Diffraction ◽  
Before And After ◽  
Natural Carbonation ◽  
Kinetics Of ◽  
Aluminate Cement ◽  
Hydrated Calcium

The carbonation of two hydrated ordinary portland cements of alkali content 1.03% or 0.43% Na2O equivalent and hydrated calcium aluminate cement (0.1% Na2O equivalent) was studied in a semi-dynamic atmosphere of 100% CO2, and 65% relative humidity at 20 ± 1 °C, for a period of 100 days. The changes of the microstructure before and during the carbonation were characterized by x-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy. The kinetics of the process was evaluated from the total CaCO3 content by means of thermogravimetric analysis. The changes of the mechanical flexural strength were also studied. The pore solution was collected and analyzed before and after different periods of time. The results were compared with those obtained under natural carbonation conditions. The results showed that the alkali content of cement does not influence the kinetics of the process when the carbonation is accelerated. In the case of natural carbonation, an induction period is produced in the ordinary portland cement of low alkali content and calcium aluminate cement. The carbonation rate of calcium aluminate cement is the slowest for accelerated and natural carbonation.

scholarly journals Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

2019 ◽  
Vol 138 (6) ◽  
pp. 4561-4569 ◽  
Author(s):  
Wiesława Nocuń-Wczelik ◽  
Katarzyna Stolarska
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Cement Kiln ◽  
Phase Assemblage ◽  
Chemical Shrinkage ◽  
High Calcium ◽  
Kinetics Of ◽  
Aluminate Cement

Abstract The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)—by-pass cement kiln dusts (BPCKD)—mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminate-based binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution—the shortening of so-called induction period in the presence of BPCKD additive—was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride—the solid and liquid components of the dust.

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

Calcium aluminate cement source evaluation for Al2O3–MgO refractory castables

2011 ◽  
Vol 37 (1) ◽  
pp. 215-221 ◽  
Author(s):  
M.A.L. Braulio ◽  
G.G. Morbioli ◽  
D.H. Milanez ◽  
V.C. Pandolfelli
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Source Evaluation ◽  
Refractory Castables ◽  
Aluminate Cement

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

Application of Magnesia-Phosphate Cement for Chromia/Alumina Castables

2012 ◽  
Vol 268-270 ◽  
pp. 625-628
Author(s):  
Jing Ming Zhao ◽  
Kyu Hong Hwang ◽  
Jong Kook Lee ◽  
Min Cheal Kim
Keyword(s):  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Furnace Lining ◽  
Iron And Steel ◽  
Good Corrosion Resistance ◽  
Refractory Castables ◽  
And Performance ◽  
The Relationship ◽  
Aluminate Cement ◽  
Alumina Castables

Refractory castables containing calcium aluminate cement (CAC) are widely used in a range of furnace lining applications in the iron and steel, cement, glass, ceramic, and petrochemical industries. However, magnesia-phosphate cement (MPC) based material could be a new types of cement material, with many advantages such as rapid hydration, high early strength and circumstance suitability, which has very important value and wide application. In this study, MPC was used at Chromia/Alumina castable as binder addition instead of conventional calcium aluminate cement. Meanwhile, it also explains the relationship between the micro-mechanism and performance by micro methods such as SEM. The results shows that MPC based castables have good corrosion resistance, interface adhesiveness and abrasion resistance.

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