Ask Dr Clark - Raw materials
Q:
LSF FORMULA
Dear sir,kiln feed is: Cao=42.3%, Mgo=2.7% ,sio2=12.90%, Al2o3=3.37%, Fe203=2.23% .some plants do not consider Mgo in calculation of LSF and they use the formula LSF=100*cao/(2.8*sio2+1.18*Al203+0.65*Fe2o3)is it right?or they should add 0.75*Mgo in numerator. if we want to announce kiln feed LSF with above analysis what should we say about LSF? LSF=102(without Mgo)or LSF=105(with considering Mgo).
A:
Normally for kiln feed LSF the MgO is not included.
Q:
Finess of raw meal influenced snow man
Hi Dr Clarck,
Can raw meal fineness(212) influenced formation of snowman?
A:
Only indirectly. This will not be the primary cause of snowman formation in a cement kiln clinker cooler.
A:
Raw materials which give the required CaO, SiO2 and Al2O3 content with the minimum of Fe2O3 contamination. No other first row transition elements can be tolerated, but they are rare components on cement raw materials or fuels.
Q:
Raw mix design of 4 components
How 4 components raw mix design are calculated and what are the LSF,SM, and AM for the mix design?
A:
Proportioning 4 raw material components to LSF, SM and AM targets involves setting up and solving 4 simultaneous equations. The LSF, SM and AM targets are variables within those simultaneous equations. I suggest that the enrol of the CemNet Cement Manufacturing Technology course.
Q:
Sweetner grade (High Grade ) Lime stone
Sir, Pls tell me, is it possible that CaO % 57 in High grade lime stone (Its LSF aprox 1050)
A:
The maximum CaO content in pure limestone (calcium carbonate) is 56%.
Q:
The ingredients in ASTM C150....
Dear Dr. Clark,
I have some questions on ASTM C150/C150m-11 Standard Specification for Portland Cement revised in April 1, 2011.
There are several ingredients specified in Item 5. Ingredient of the specification,
5.1.1 Portland Cement Clinker
5.1.2 Water or Calcium Sulfate
5.1.3 Limestone (not more than 5 %)
5.1.4 Inorganic Processing additions (not more than 5 %)
5.1.5 Organic Processing additions (not more than 1 %)
5.1.6 Air-entraining addition
Would you be more specific about the following aspects?
1. What's the meaning of Water of "5.1.1 Water or Calcium Sulfate" ?
2. What's the meaning of Processing additions ?
What's the difference between 5.1.3 and 5.1.4 ?
3. What's the maximum addition rate ? Not more than 10 %?
4. What's the meaning of 5.1.5 ? Does it mean grinding aids?
5. What's the purpose the us government revised the specification like this? For the reduction of CO2 emission?
I really thank you for your help up to now!
Best Regards.
A:
Dear Obong,
The short answer is I don't knnow exactly. I presume the reference to water or calcium sulphate is saying that the calcium sulphate addition might be gypsum with 2 molecules of water of crystallisation. I think inorganic processing additions are pfa, gbs, etc. so the same as limestone. As far as I I am aware the total additions are 10%, including the gypsum. I think organic processing additions are grinding aids and organic quality improvers. I don't know the motives of ASTM or the US Government but this seems to be a move towards EN197 CEM I cements.
Q:
Intensity of kiln feed
Hi sir
How we can get the analyze of material , from intensity of kiln feed?
Best regard
A:
I presume you mean the intensify of the fluorescent X-radiation from a kiln feed sample in X-ray fluorescense spectrometer. These are calibrated so that the SiO2, Al2O3, Fe3O3, CaO, etc.content of the kiln feed is correlated with the X-ray intensity.
