77 posts
TimePosted 17/06/2011 12:57:45
Vikpro says

Re: Request for feedback for a Two Chamber Cement Mill Ball Charge and Longitudinal Sieve Analysis

As per your given mill details.(mill output assumed to be 45 tons / hr) for more details you can contact me at It is not so easy to understand the cement plant without being present at site. But, still according to my calculations- - The size of your first chamber grinding media seems to be more.

- Max ball size should be upto 70 mm

Data entry - Yellow cells

Mill tube Length                 Mts.11.00
Mill tube Dia.                      Mts.3.4
Mill liner size                      Mts.0.14
Partition Wall size              Mts.0.7
Nos of partition1
First comp. Length ( effect)     Mts.2.3
First Comp. Useful Mill Dia. Mts3.23
Second comp. length ( effect) Mts.8
Second Cmp.Useful Mill Dia. Mts3.27
Third comp. length ( effect)    Mts.0
Third Comp. Useful Mill Dia. Mts0
Mill RPM17.2
Size in microns, 80% of mill feed pass F11000
Bond's works index of mill feed, size  Wi13.49
Specific gravity of mill feed.    S3.09
Volume of first Comp.   M318.84
Power demand cal. 1st Comp399
Volume of second Comp.M367.15
Power demand cal. 2nd Comp1389
Volume of third Comp.M30
Power demand cal. 3rd Comp0
Power demand  total.  Kw ( Aprox)1824
Useful Mill Length                Mts10.3
Material retaintion time min6.3
Mill Critical Speed 23.54
Mill speed of critical speed %73.07
First compartment
% of filling first compartment32.7%
Grinding Area of first Comp. %21.9%
Compartment Volume  M318.8M3
Total Bulk Weight of balls28.5tons
Bulk density of all balls.4.631t /d m3
Bulk Volume6.2M3
Total Numbers of Balls34559#s
Nos. Of ball impact/ revolution.61861Impacts
Nos of Ball impact / sec17733Impacts
Material retaintion time ( min )1.41min
Average Ball Weight0.8kg
Ball Surface/Comp. Volume Ratio27.1 
Second compartment
% of filling second compartment29.8%
Grinding Area of second Comp. %78.1 
Compartment Volume  M367.15m3
Total Bulk Weight of Balls98.0tons
Bulk density of balls.4.89t / dm3
Bulk Volume20.03m3
Total Numbers of Balls3564486.2#s
Nos. Of ball impact / revolution.6380430Impacts
Nos of Ball impact / sec1829057Impacts
Material retaintion time ( min )4.89min
Average Ball Weight0.027kg
Ball Surface/Comp. Volume Ratio80.0 


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81 posts
TimePosted 18/06/2011 11:39:27
fjalali says

Re: Request for feedback for a Two Chamber Cement Mill Ball Charge and Longitudinal Sieve Analysis

Hey all my email is:

I would be happy to send you my calculationa andexcel data sheets.




81 posts
TimePosted 18/06/2011 11:59:39
fjalali says

Re: Request for feedback for a Two Chamber Cement Mill Ball Charge and Longitudinal Sieve Analysis

Regarding the questions asked:

  • is it an open-circuit ball mill or a closed-cicuit? Closed Circut.
  • are you using steel balls or ceramic balls? Steel Balls
    (could be ceramic sometimes for white cement)
  • are you producing one main product or
    are you producing several different products? One type white cement wth around 4000 blain
  • eventually, what kind of separator is being used? Dont Have
    how does the separation curve looks like,
    how much is the bypass ratio,
    circulating load, ....
  • what is the (main) product being produced?
    what are the raw materials and the recipe? 95% clinker and 5% gypsum
    what is the fineness of the cement Around 4000 blain
    particle size distribution of the cement, ...
  • are you using grinding aids? Very little
  • what are the temperatures in the grinding circuit? Dont have
  • if it is a closed circuit, could you provide the
    particle size distribution of the separator feed, reject, product?
  • what is the current power consumption and hourly production
    and what is the current rotation speed?
  • It could be also useful to explain the symbols you are using!
    Is D80 related to the feed or the product? Feed
    Some people write P80 when it is the product and F80 for the feed !
    What do you mean by Pc, for example? Percent of critical speed
    What are s or K?
    Also show all the units in your data, I guess D80 is in µm? Yes
    What do you call "critical speed", and what are the units?
  • Would should also provide the formulas you are using.
    Attaching an Excel file would be the easiest way.
  • I attached the formula and excel sheet. I dont have any data regarding the seperator.


    26 posts
    TimePosted 23/04/2016 21:51:38
    GLT says

    re Re: Request for feedback for a Two Chamber Cement Mill Ball Charge and Longitudinal Sieve Analysis

    Dear experts,

    could you please, send me a excel calculation sheet to calculate ball charge optimization for two chamber cement ball mill .

    mail ID


    thank you in advance