SDM Mill Calcs.xls

8/18/2019 SDM Mill Calcs.xls

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To use enter the required data or use the drop down list in the highlighte

This form is based on the work of Fred C. Bond and others.

Input Values

Wi = Bond Work kWh!short ton "Imperial units# 14 kWh!ton

F = Feed $%& passing si'e in microns 12500 microns

( = (roduct $%& passing si'es in microns 150 microns

Basic )nerg* Consumption

W = Basic energ* required 10.18 kWh!ton

W = Wi+",%!(-%./,%!F-%.# kWh!ton


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d cells


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To use enter the required data or use the drop down list in the highlighted cells

This form is for calculating the basic ball!rod!pebble mill factors.

This should be used as a guide onl* with proper testing used for f inal selection.

This form is based on the work of Fred C. Bond and others.

Basic Input

Bond Work kWh!short ton Wi = 14.5 kWhr!st

Feed $%& passing si'e in microns F = 12500 F$%

(roduct $%& passing si'es in microns ( = 150 ($%

Basic Energy Consumption

Basic energ* required W = 10.54 kWh!ton

(ro0ect1

Feed Tonnage1

B* *ear 2,%%%% t!*r

B* 3a* 600 t!d

B* 4our 2$ t!hr

5perating 6chedule1 hours 24 h!d

da*s 7 d!w

weeks 50 w!*r

7ross 4ours!*ear $8%% h!*r 9:ailabilit*1 90 &

9ctual 5perating1 2,.; h!d

ill 3efinition

T*pe Ball Mill

Wet or 3r*1 et

Circuit ?5pen or Closed@1 Close!

>ill 3iameter 3 = 14 ft

>ill Aength A = 10 ft

re:olutions!minute = 12.0 re:!min

A to 3 check / for od >ills ?if A is 2+3 rods can tumble and tangle@ D

Enit Volume ,G 9ssumed 3ri:e Aosses1 5 &

ills ill T*pe Factor ?for makeup ball!rod!pebble si'e@ / H2 H2 = ""0

Basic energ* required / per mill 2G2.$8 kWh

G2.% 4p

Capacit* check / based on actual mills installed b* Boliden Hoppers # ;;2

ft

ft


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9d0ustment factors

Ball charge efficienc* factor Bcef = 1.22

drop from inside top of mill to lowest discharge point J = 10.50

ball charge :olume fraction V = 2,.$&

Fine grinding factor Fgf = 0.9"

>ill diameter factor for mill diameter 3 Fmd = 0.89eduction ratio r = $.

eduction ratio ro = ,,.;

eduction ratio efficienc* factor ef = 1.00

6hell speed factor for shell speed 6sf = 1.""

where K=/"3!,.%$#- K = %.

6hell speed 6 = $.$% ft!sec

>ill T*pe >T 1.00

Wet or 3r* )F, 1.00

Circuit T*pe )F2 2.00

3iameter efficienc* )F 0.91

Comminution energy nee!e! $

)nerg* transfer required within mill shell )t = 26.28 kWh!ton

Internal energ* required / per mill 7"0.11 kWh

979.08 4p

Capacit* check / based on actual mills installed b* Boliden Hoppers # ,,,

Mill %o&er 'ra&Ball mass Bm = ,;2.G,

Ball charge power factor Bcpf = 1.41

Base power draw Bpd = ;.2+A+3%.8+Bm "L ,,.2+A+32.8 maMimum# Bpd =

"$ ft wet o!f discharge mill & critical speed# %.8$

Critical speed factor Csf = 0.80

& Critical speed Cs = $.;2&

Theoretical critical speed re:!min ill power draw >pd = 14.18 kWhr

(otal %o&er

Comminution 7"0.11 kWhr

(er >ill 7"0.11 kWhr

>ill (ower 3raw 14.18 kWhr

Total 744.29 kWhr

998.09 4p

Capacit* check / based on actual mills installed b* Boliden Hoppers # ,

ft

ft


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Currentl* E6 units onl*

W = Wi+",%!(-%./,%!F-%.# kWh!ton

) to ' *+ay

,.%% ?cast iron@ ,.%$ ?steel@ ,.,, ?forged@

Wet (ebble / ,%3r* (ebble / , od / %% 3r* Ball %! Wet Ball %

= W +t!hr ! N mills

Mill si,ing o+ay


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Bcef = "%.8!V#-%.

assume & of 3 or input if known

V = ,.,/,.2;+J!Wi

Fgf = ?(O,%.@!,.,8( for ( microns

Fmd = "$!3#-%.2r = F!(

ro = $ O+A!3

ref = ?2%+?r /,.@ O2.;%@!?2%+?r/,.@@

6sf = "2 / 2.$!6#-K

Based on Ball = , od = 2 697 = 97 = 8

Based on Wet = , 3r* = ,.

Based on 5pen =, Closed = 2

)t = W+Bcef+Fgf+Fmd+ref+6sf+>T+)F,+)F2+)F kWh!ton

Mill si,ing o+ay

Bm = .$2+H,+V+3-2

Bcpf = ,.$ / ,.;GV

Bpd = ;.2+A+3-%.8+Bm !?,,.2+A+3-2.8@

Csf = ,.$+Cs+",/%.,+?2,%+Cs/G@#

Cs = +?3-%.@!;.;

pd = Bcpf+Bpd+Csf+Adf+rpf+6f kW

t!hr + )t

Mill si,ing o+ay


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5pen Wet od >ill ,.%% for cast iron balls

Closed 3r* Ball >ill ,.%$ for steel balls

97 ?9utogenous@ ,.,, for forged balls

697 ?6emi/autogenous@

,% Wet (ebble

, 3r* (ebble

%% od

3r* Ball

% Wet Ballû >ill too small for required 4pü >ill si'ing oka*û >ill Aength to short for od >ill A 2+3ü A to 3 5ka*


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H Factor

7rindlng >edia C.I. Balls (ebbles

Wet/5:erflow/5pen Circuit % /

Wet/5:erflow/Closed Circuit % /

Wet/3iaphragm/5pen Circuit % ,%

Wet/3iaphragm/Closed Circuit % ,%

3r*/3iaphragm/5pen Circult ,

3r*/3iaphragm/Closed Circuit ,


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SDM Mill Calcs.xls

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