MK750 : SiO2=68% ; Al2O3=29%
WG: SiO2= 29 % ; Na2O =13%
[NaOH]=10M
Formulation : MK750=450g ; Sand =1350g ; Liquid/Solid=0.65 ; WG/NaOH= 1.5 ;
I need a details of all calculations ;
My Email : [email protected]
Hi, you've got: Si/Al = 2.2; Al/Na = 1; H2O/Na2O = 11.5
You can refer to the following work:
Method AMiDsT v1.0 Alkali-activated-materials Mix Design Tool
Thank you Luca Valentini . I am inquiring how one would use the AMiDsT software to calculate the mole ratios when they are using a mixture of Sodium hydroxide and Sodium silicate solution as their activator solution.
A case in point;
MKC; SiO2 = 63.4065%, Na2O = 32.1216%
WG; SiO2 = 28.53%, Na2O = 14.78%
concentration of NaOH = 10M
MKC = 106.7g, masss of WG = 35.6 g, (mass ratio) WG/NaOH = 2.0
I seek your guidance about this: My email adress is [email protected]
Ampumuza Mmukunda hello, you can proceed by first defining your sodium silicate activator in "DEFINE ACTIVATOR", then add the needed proportions of NaOH and H2O, for your 10M solution, in "PREDEFINED COMPOSITIONS". Then click on "Calculate M" and you'll get the overall SiO2/Na2O of the blended activator.
Hello Luca Valentini . Thank you for the guidance through this. I have run the analysis in AMiDsT software with this data and this is what I obtained:
The data I used:
MKC; SiO2 = 63.4065%, Na2O = 32.1216%
WG; SiO2 = 28.53%, Na2O = 14.78%
concentration of NaOH = 10M
MKC = 1080g, masss of WG = 240.3 g, (mass ratio) WG/NaOH = 2.0
The proportions of NaOH needed; NaOH = 34.2g and H20 = 85.5g
In adition to this I defined the Solution concentration under "Define activator" as 56.69%.
I obtained a value of 1.2389 corresponding to Si02/Na20 and
Si/Al = 1.90
H/Na = 9.18
Can please help me confirm if I am on the right track. And is the ratio obtained as H/Na different from H20/Na20?
Attached is a screen shoot of my results.
Ampumuza Mmukunda your calculation is nearly OK. The concentration of the activator should be given by the sum of Na2O and SiO2, so it is 43.31. Also, I calculated a slightly larger value of Na2O/SiO2 of about 2, rather than 1.93 (notice that this ratio should be in moles in the software). In general, your Na/Al is way too low, and I think you can expect low reactivity, other than much likely poor workability. I suggest that you increase the amount of activator to something like 975 g, to target a Na/Al ratio of 0.8. See how it goes.
In general, I believe that the problem with metakaolin is that it requires too much activator, from this point of view low grade clays work much better. To reduce the amount of alkaline activator you can even blend your metakaolin with some relatively inert powder, say 30% CaCO3. In that way you can proportionally reduce the amount of your activator.
Good luck.
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