Activation of Slag Cement by Hydrated Lime

2011 ◽  
Vol 71-78 ◽  
pp. 706-711 ◽  
Author(s):  
A Naceri ◽  
M.S Bouglada ◽  
A Belouar

In this experimental study, the setting agent Ca(OH)2 used for activation of slag cement is used in the proportions of 0%, 2%, 4%, 6%, 8% and 10% by substitution method by mass of slag cement. The results indicated that the mineral activator has a significant effect on the flexural and compressive strengths. The optimum percentage of the mineral activator (hydrated lime) ranges between 2 to 4%. The activation of the slag cement by fine lime (calcium hydroxide) is a simple and economic method especially for cement containing not very reactive slag or low reactivity due to its low CaO/SiO2.

2013 ◽  
Vol 634-638 ◽  
pp. 741-745
Author(s):  
Lin Bo Qin ◽  
Jun Han ◽  
Tie Mi ◽  
Long Liu ◽  
Hao Wang ◽  
...  

In this paper, the desulphurization of coals prepared briquettes using lime based products (calcium hydroxide and calcium carbonate) and sodium hydroxide as desulphurizing agents (DSA) was investigated in a vertically integrated experimental furnace. Meanwhile, the effect of sodium hydroxide on the denitrification was also studied. The results indicated that calcium carbonate as a DSA is more efficient for SO2 removal during the char combustion, whereas hydrated lime and NaOH are efficient in both char and volatile combustion. For most of the coals, the desulfurization efficiencies in case of lime hydrated reaches over 80 %, whereas desulfurization efficiencies is below 70% when calcium carbonate is used as DSA. It was also found that NaOH can be used as denitrifying agent as well as desulphurizing agent, and the maximum denitrifying efficiencies by using NaOH denitrifying agents for coal A and coal B are 59% and 54%, respectively.


2021 ◽  
Vol 289 ◽  
pp. 123201
Author(s):  
Juan He ◽  
Wenbin Bai ◽  
Weihao Zheng ◽  
Junhong He ◽  
Guochen Sang

ACS Omega ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 3130-3139
Author(s):  
Javier A. Grajales ◽  
Lisa M. Pérez ◽  
A. Paul Schwab ◽  
Dallas N. Little

2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Anuar Othman ◽  
Nasharuddin Isa ◽  
Rohaya Othman

Precipitated calcium carbonate (PCC) chemically can be synthesized in the laboratory. In this study, hydrated lime or calcium hydroxide was used as raw material with sucrose as additive to produce PCC. The process was compared with the one without additive. PCC produced was observed based on morphology, mineral composition and size by using Fesem-Edx and LPSA, respectively. PCC products without additive demonstrated fine and more uniform size of calcite PCC as compared to the one with additive. Nevertheless, the process with additive produced more PCC product than without additive.


1923 ◽  
Vol 15 (3) ◽  
pp. 269-269
Author(s):  
A. S. Behrman ◽  
F. R. Porter

2020 ◽  
Vol 184 ◽  
pp. 01109
Author(s):  
C Chandana Priya ◽  
M V Seshagiri Rao ◽  
V Srinivasa Reddy ◽  
S Shrihari

SCC is expensive when compared with normal conventional concrete. Hence, it is desired to produce low cost SCC by replacing cement with higher percentages of fly ash, which is a no cost material and available in abundance. At the same time to achieve higher grade HVFASCC, micro silica which is otherwise condensed silica fume can also be used along with fly ash to enhance the strength properties of HVFASCC. By replacing fly ash in high volumes in the mix, high amount of pozzolanic material becomes available, majorly reactive silica, for which more calcium hydroxide is necessary for further pozzolanic reaction. As we are reducing cement quantity, the amount of calcium hydroxide available is reduced thus demanding external addition of hydrated lime which can be supplied as additive to cater to the need of calcium hydroxide required for reactive silica in fly ash.The present investigation aims to achieve strength for high volume fly ash self-compacting concrete. The replacement of cement with fly ash is made in 45%, 50%, 55%, 60%, 65% and 70% with 20% hydrated lime and 10% silica fume in one trial. In another trial, 30% hydrated lime and 10% silica fume is added with replacement of fly ash to cement varying in same percentages. The design mix is tested for workability and flowability and cubes are casted for compression strength test and tested at 28 day,, 56 day, and 90 day,.


2013 ◽  
Vol 857 ◽  
pp. 70-74
Author(s):  
Sheng Bo Zhou ◽  
Ai Qin Shen ◽  
Geng Fei Li

In order to investigate the activity of different original slags and the coupled relation between the slag and the clinker, the simplified slag cement system was designed in the experiment, in which clinker was replaced by lime.The reactional degree of slag in cement was determined through using chemical combined water content method, and the hydration processs were determined through using DSC-TGA. The results showed that for the different original slags, the destruction and rebuilding process of their microstructure were important to distinguish the activity of slags. And the process of slag hydration mainly experienced two stages, including microstructure destruction at early ages and microstucture rebuilding at later ages. And the variation of Calcium hydroxide content in cement indicated the interaction between the slag and clinker, and slag may improve the clinker hydration velocity.


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