Ball Mill (Perfect Mixing)

Description

This is an implementation of the Whiten Perfect Mixing ball mill model described by Napier-Munn et al.

The model described here is for steady-state simulation. For dynamic simulation, see Ball Mill (Perfect Mixing, Dynamic).

Model Theory

The Perfect Mixing model is based on a population balance of particles entering the mill, breaking into smaller sizes, and discharging as product. For a mill operating in steady-state, the following diagram represents the balance for a given size fraction:

The steady-state population balance is formulated mathematically as:

$f_{i}-R_{i}s_{i}+\sum _{j=1}^{i}{A_{ij}R_{j}s_{j}}-D_{i}s_{i}=0$

where:

• $f_{i}$ is the mass feed rate of solids in size interval $i$
• $p_{i}$ is the mass product rate of solids in size interval $i$
• $s_{i}$ is the mass of solids in the mill load in size interval $i$
• $R_{i}$ is the breakage rate of solids in the mill load in size interval $i$
• $D_{i}$ is the rate of discharge from the mill of solids in size interval $i$
• $A_{ij}$ is the Appearance function, the distribution of particle mass arising from the breakage of a parent particle in size interval $j$ into progeny of size interval $i$

As the mill is perfectly mixed, the product is defined by the mill contents and discharge rate as:

$p_{i}=D_{i}s_{i}$

Noting also that

$s_{i}={\frac {p_{i}}{D_{i}}}$

leads to

$f_{i}-{\frac {R_{i}}{D_{i}}}p_{i}+\sum _{j=1}^{i}{A_{ij}{\frac {R_{j}}{D_{j}}}p_{j}}-p_{i}=0$

and

$p_{i}={\frac {f_{i}+\sum _{j=1}^{i}{A_{ij}{\frac {R_{j}}{D_{j}}}p_{j}}}{1+{\frac {R_{i}}{D_{i}}}}}$

The mill product can therefore be computed provided a feed rate, Appearance function and breakage rate per discharge rate, ${\frac {R_{i}}{D_{i}}}$, is available. Alternatively, the ${\frac {R_{i}}{D_{i}}}$ function can be determined from the feed rate, product rate and Appearance function.

Discharge rate

The discharge rate, $D_{i}$, is related to the residence time of pulp in the mill and can be corrected for different volumetric feed rates and mill volumes by first normalising to

$D_{i}^{*}={\frac {D_{i}}{\left({\frac {4Q_{v}}{D^{2}L}}\right)}}$

where:

• $D_{i}^{*}$ is the residence time normalised discharge rate per size interval $i$
• $Q_{v}$ is the volumetric flow rate of pulp in mill feed (solids plus liquids)
• $D$ is the mill diameter (inside liners)
• $L$ is the mill length

The actual discharge rate for a given mill and pulp feed rate is subsequently scaled as

$D_{i}=D_{i}^{*}\cdot {\frac {4Q_{v}}{D^{2}L}}$

with ${\frac {R_{i}}{D_{i}}}$ becoming ${\frac {R_{i}}{D_{i}^{*}}}$ for mill model calibration and simulation.

Breakage rate

The ${\frac {R_{i}}{D_{i}^{*}}}$ rate is a function of particle size and is typically a smooth, concave downward curve with a maximum related to ball size. In order to reduce the number of model parameters, the rates are specified only at three or four regularly spaced sizes (knots). Cubic spline interpolation is then used to reconstruct the complete set of rates for all size intervals.

The breakage rate, $R_{i}$, is affected by mill operating conditions and the ${\frac {R_{i}}{D_{i}^{*}}}$ rate is further scaled by the following relation:

$\left({\frac {R}{D^{*}}}\right)_{Sim}=\left({\frac {R}{D^{*}}}\right)_{Fit}\cdot Factor_{D}\cdot Factor_{LF}\cdot Factor_{FracCS}\cdot Factor_{WI}\cdot Factor_{Db}$

The scaling factors are defined as:

$Factor_{D}={\sqrt {\frac {D_{Sim}}{D_{Orig}}}}$

$Factor_{LF}={\frac {(1-LF_{Sim}).LF_{Sim}}{(1-LF_{Orig}).LF_{Orig}}}$

$Factor_{FracCS}={\frac {FracCS_{Sim}}{FracCS_{Orig}}}$

$Factor_{WI}=\left({\frac {WI_{Orig}}{WI_{Sim}}}\right)^{0.8}$

$Factor_{Db}=\left\{{\begin{array}{l}{\frac {Db_{Orig}}{Db_{Sim}}}&{\text{for }}x<x_{m(small)},\;\;\;x_{m(small)}=\min {\left(K.Db_{Orig}^{2},K.Db_{Sim}^{2}\right)}\\\left({\frac {Db_{Orig}}{Db_{Sim}}}\right)^{2}&{\text{for }}x\geq x_{m(large)},\;\;\;x_{m(large)}=\max {\left(K.Db_{Orig}^{2},K.Db_{Sim}^{2}\right)}\\\end{array}}\right.$

where:

• $D$ is mill diameter
• $LF$ is load fraction, the load volume as a fraction of mill volume
• $FracCS$ is the fraction critical speed of the mill
• $WI$ is the Bond ball work index of the ore
• $Db$ is the ball diameter
• $K$ is the maximum breakage rate factor which relates ball size and the size at which ${\frac {R_{i}}{D_{i}^{*}}}$ is maximum, i.e. $x_{m}=K.D_{b}^{2}$

and the $Orig$ subscript refers to the original mill from which ${\frac {R_{i}}{D_{i}^{*}}}$ was derived and $Sim$ refers to the mill being simulated (scaled).

The grouping of breakage rate scaling factors above, excluding work index, essentially represent a relationship with mill power draw, as noted by Napier-Munn et al., King and others.

Appearance function

The Appearance function describes the mass-by-size distribution of progeny particles resulting from the breakage of parent particles.

The Appearance function may be specified for a particular ore. Alternatively, the default Broadbent-Callcott appearance function may be used, which is defined as:

$A_{ij}={\frac {1-\exp(-{\frac {d_{i}}{d_{j}}})}{1-\exp(-1)}}$

where $d_{i}$ is the breakage product particle size and $d_{j}$ is the original particle size.

Internal mesh series

The Perfect Mixing ball mill model is formulated internally with a geometric progression of mesh sizes at ${\sqrt {2}}$ intervals. Feed and product size fractions are automatically converted to and from the internal mesh series during model computation. The ${\sqrt {2}}$ size intervals allow the Appearance function to be specified as a one-dimensional matrix, rather than the two dimensional form defined above, since

$A_{ij}=A_{i-j}$

when the intervals are so spaced.

Power draw

The Whiten Perfect Mixing mill model formulation does not explicitly include a relationship with mill power draw, other than the breakage rate scaling observations noted above.

However, a simple estimate of power draw is provided for user convenience. Power is calculated according to Morrell's empirical approach for grate and overflow mills.

Multi-component modelling

The original Whiten Perfect Mixing model formulation only considered the properties of a single ore type.

This model internally applies different Appearance functions and breakage rate scaling to separate population balance computations for each ore type in the feed, as conceptually suggested by Napier-Munn et al.

Dynamic modelling

Main article: Ball Mill (Perfect Mixing, Dynamic)

Excel

The Perfect Mixing ball mill model may be invoked from the Excel Formula Bar with the following function call:

=mdUnit_BallMill_PerfectMixing(Parameters as Range, Size as Range, MillFeed as Range, OreSG As Range, WorkIndexSim As Range, Appearance as Range, R/D*KnotPositions as Range, R/D*KnotsOrig as Range)

Invoking the function with no arguments will print Help text associated with the model.

Inputs

The required inputs are defined below in matrix notation with elements corresponding to cells in Excel row ($i$) x column ($j$) format:

$Parameters={\begin{bmatrix}Mill\;diameter\;(original){\text{ (m)}}\\Load\;fraction\;(original){\text{ (v/v)}}\\Fraction\;critical\;speed\;(original){\text{ (frac)}}\\Work\;Index\;(original){\text{ (kWh/t)}}\\Ball\;top\;size\;(original){\text{ (mm)}}\\Mill\;diameter\;(simulated){\text{ (m)}}\\Load\;fraction\;(simulated){\text{ (v/v)}}\\Fraction\;critical\;speed\;(simulated){\text{ (frac)}}\\Ball\;top\;size\;(simulated){\text{ (mm)}}\\Max\;breakage\;rate\;factor,K{\text{ (mm}}^{\text{-1}}{\text{)}}\\Belly\;length{\text{ (m)}}\\Cone\;angle{\text{ (deg.)}}\\Trunnion\;diameter{\text{ (m)}}\\Ball\;charge\;vol.fraction{\text{ (v/v)}}\\Void\;fill\;volume\;fraction{\text{ (v/v)}}\\Ball\;SG{\text{ (t/m}}^{\text{3}}{\text{)}}\\Liquids\;Q_{m}{\text{ (t/h)}}\\Liquids\;SG{\text{ (t/m}}^{\text{3}}{\text{)}}\\\end{bmatrix}},\;\;\;\;\;\;Size={\begin{bmatrix}d_{1}{\text{ (mm)}}\\\vdots \\d_{n}{\text{ (mm)}}\\\end{bmatrix}},\;\;\;\;\;\;MillFeed={\begin{bmatrix}Q_{11}{\text{ (t/h)}}&\dots &Q_{1m}{\text{ (t/h)}}\\\vdots &\ddots &\vdots \\Q_{n1}{\text{ (t/h)}}&\dots &Q_{nm}{\text{ (t/h)}}\\\end{bmatrix}},\;\;\;\;\;\;OreSG={\begin{bmatrix}SG_{1}{\text{ (t/m}}^{\text{3}}{\text{)}}&\dots &SG_{m}{\text{ (t/m}}^{\text{3}}{\text{)}}\\\end{bmatrix}}$

$WorkIndex_{Sim}={\begin{bmatrix}WorkIndex_{1}{\text{ (kWh/t}}&\dots &WorkIndex_{m}{\text{ (kWh/t}}\\\end{bmatrix}},\;\;\;\;\;\;Appearance={\begin{bmatrix}{\begin{bmatrix}A_{1}{\text{ (frac)}}\\\vdots \\A_{31}{\text{ (frac)}}\\\end{bmatrix}}_{1}\dots {\begin{bmatrix}A_{1}{\text{ (frac)}}\\\vdots \\A_{31}{\text{ (frac)}}\\\end{bmatrix}}_{m}\end{bmatrix}},\;\;\;\;\;\;{\frac {R}{D^{*}}}KnotPositions={\begin{bmatrix}d_{1}{\text{ (mm)}}\\\vdots \\d_{k}{\text{ (mm)}}\\\end{bmatrix}},\;\;\;\;\;\;{\frac {R}{D^{*}}}KnotOrig={\begin{bmatrix}\ln \left({\frac {R}{D^{*}}}\right)_{1}\\\vdots \\\ln \left({\frac {R}{D^{*}}}\right)_{k}\\\end{bmatrix}}$

where:

• $n$ is the number of size intervals
• $m$ is the number of ore types
• $k$ is the number of breakage rate per discharge rate knots
• $d_{i}$ is the size of the square mesh interval that feed mass is retained on (mm)
• $d_{i+1}<d_{i}<d_{i-1}$, i.e. descending size order from top size ($d_{1}$) to sub mesh ($d_{n}=0$ mm)
• $Q$ is feed mass flow rate (t/h)
• $SG$ is Specific Gravity or density (- or t/m³)
• $A_{i}$ is the Appearance function value, the fraction of parent particle mass appearing in size interval $i$ (frac)
• ${\frac {R_{i}}{D_{i}^{*}}}$ is breakage rate per discharge rate normalised for residence time (h^-1/h^-1/h)

Results

The results are displayed in Excel as an array corresponding to the matrix notation below:

$mdUnit\_BallMill\_PerfectMixing={\begin{bmatrix}{\begin{bmatrix}{\text{Mill volumetric feed rate (m}}^{\text{3}}{\text{/h)}}\\{\text{Mill volume (m}}^{\text{3}}{\text{)}}\\{\text{Mill speed (rpm)}}\\{\text{Charge density (t/m}}^{\text{3}}{\text{)}}\\{\text{No-load power (kw)}}\\{\text{Gross power (grate)}}\\{\text{Gross power (overflow) (kW)}}\\{\text{R/D* factor (frac)}}\\{\text{Factor D (frac)}}\\{\text{Factor LF (frac)}}\\{\text{Factor Cs (frac)}}\\{\text{xm(small) (mm)}}\\{\text{xm(large) (mm)}}\\\end{bmatrix}}&{\begin{array}{ccc}{\begin{bmatrix}d_{1}{\text{ (mm)}}\\\vdots \\d_{n}{\text{ (mm)}}\end{bmatrix}}&{\begin{bmatrix}Q_{11}{\text{ (t/h)}}&\dots &Q_{1m}{\text{ (t/h)}}\\\vdots &\ddots &\vdots \\Q_{n1}{\text{ (t/h)}}&\dots &Q_{nm}{\text{ (t/h)}}\\\end{bmatrix}}&{\begin{bmatrix}{\bar {d}}_{1}{\text{ (mm)}}\\\vdots \\{\bar {d}}_{n}{\text{ (mm)}}\\\end{bmatrix}}&{\begin{bmatrix}{\frac {R_{i}}{D_{i}^{*}}}_{11}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}/{\text{h}}\right)&\dots &{\frac {R_{i}}{D_{i}^{*}}}_{1m}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}/{\text{h}}\right)\\\vdots &\ddots &\vdots \\{\frac {R_{i}}{D_{i}^{*}}}_{n1}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}/{\text{h}}\right)&\dots &{\frac {R_{i}}{D_{i}^{*}}}_{nm}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}/{\text{h}}\right)\\\end{bmatrix}}&{\begin{bmatrix}{\frac {R_{i}}{D_{i}}}_{11}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)&\dots &{\frac {R_{i}}{D_{i}}}_{1m}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)\\\vdots &\ddots &\vdots \\{\frac {R_{i}}{D_{i}}}_{n1}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)&\dots &{\frac {R_{i}}{D_{i}}}_{nm}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)\\\end{bmatrix}}&{\begin{bmatrix}\ln \left({\frac {R_{i}}{D_{i}}}\right)_{11}&\dots &\ln \left({\frac {R_{i}}{D_{i}}}\right)_{1m}\\\vdots &\ddots &\vdots \\\ln \left({\frac {R_{i}}{D_{i}}}\right)_{k1}&\dots &\ln \left({\frac {R_{i}}{D_{i}}}\right)_{km}\\\end{bmatrix}}\\\\&&&&&{\begin{bmatrix}\left({\frac {R_{i}}{D_{i}}}\right)_{11}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)&\dots &\left({\frac {R_{i}}{D_{i}}}\right)_{1m}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)\\\vdots &\ddots &\vdots \\\left({\frac {R_{i}}{D_{i}}}\right)_{k1}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)&\dots &\left({\frac {R_{i}}{D_{i}}}\right)_{km}\left({\frac {{\text{h}}^{\text{-1}}}{{\text{h}}^{\text{-1}}}}\right)\\\end{bmatrix}}\\\\&&&&&{\begin{bmatrix}FactorWI_{1}&\dots &FactorWI_{m}\end{bmatrix}}\\\end{array}}\end{bmatrix}}$

where $Q$ is product mass flow rate (t/h), ${\bar {d}}_{i}$ is the size of the geometric mean size of the internal mesh series interval that mass is retained on (mm), and all other variables are as defined previously.

Example

The images below show the selection of input arrays and output results in the Excel interface.

Parameters (blue frame) Results (light blue frame)

Size (red frame), OreSG (green frame) and MillFeed (purple frame)

Appearance (pink frame), R/D*KnotPositions (teal frame), R/D*KnotsOrig (blue frame), WorkIndexSim (red frame)

SysCAD

The SysCAD interface for steady-state (ProBal) mode is described below. For SysCAD Dynamic, see Ball Mill (Perfect Mixing, Dynamic).

ScdMD*BallMill page

The first tab page in the access window will have this name.

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
Tag	Display	This name tag may be modified with the change tag option.
Condition	Display	OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount	Display	The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc	Display	This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the unit class ID.
Requirements
On	CheckBox	This enables the unit. If this box is not checked, then the material will pass straight through the mill with no change to the size distribution.
Method	Perfect Mixing	The Whiten Perfect Mixing model is used to determine the mill product size distribution. Different parameters can be used for different solids..
	Herbst-Fuerstenau	The Herbst-Fuerstenau model is used to determine the mill product size distribution. Different parameters can be used for different solids.. See Mill (Herbst-Fuerstenau).
Options
ShowQFeed	CheckBox	QFeed and associated tab pages (eg Sp) will become visible, showing the properties of the combined feed stream.
ShowQProd	CheckBox	QProd and associated tab pages (eg Sp) will become visible, showing the properties of the products.
PowerModels	CheckBox	Show alternative tumbling mill power model calculations on the Power page.
MediaTrajectory	CheckBox	Show mill media rolling, sliding and free flight trajectory computations on the MediaTraj page.
OverfillingIndicator	CheckBox	Show overflow ball mill slurry volume, residence time, and overfilling evaluation on Overfilling page.
SizeForPassingFracCalc	Input (global)	Size fraction for % Passing calculation. The size fraction input here will be shown in the Stream Summary section.
FracForPassingSizeCalc	Input (global)	Fraction passing for Size calculation. The fraction input here will be shown in the Stream Summary section.
Stream Summary
MassFlow / Qm	Display	The total mass flow in each stream.
SolidMassFlow / SQm	Display	The Solids mass flow in each stream.
LiquidMassFlow / LQm	Display	The Liquid mass flow in each stream.
VolFlow / Qv	Display	The total Volume flow in each stream.
Temperature / T	Display	The Temperature of each stream.
Density / Rho	Display	The Density of each stream.
SolidFrac / Sf	Display	The Solid Fraction in each stream.
LiquidFrac / Lf	Display	The Liquid Fraction in each stream.
Passing	Display	The mass fraction passing the user-specified size (in the field SizeForPassingFracCalc) in each stream.
Passes	Display	The user-specified (in the field FracForPassesSizeCalc) fraction of material in each stream will pass this size fraction.

Mill page

The Mill page is used to specify the input parameters for the mill model.

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
Requirements
NumParallelUnits	Input	The number of parallel, identical units to simulate. Feed is divided by the number of parallel units before being sent to the unit model. Unit model product is multiplied back by the same value and returned to the SysCAD product stream. All unit model result values are shown per parallel unit.
Scaling
Diameter	Input	The inside liner diameter of the original and simulated ball mills.
BellyLength	Input	The inside liner belly length of the simulated ball mill, excluding cones.
ConeAngle	Input	Angle of the feed and discharge end cones, measured as positive displacement from the vertical direction.
Diameter	Input	The inside liner trunnion diameter of the simulated ball mill.
LoadFrac	Input	The volumetric load fraction of the original and simulated ball mills.
FracCS	Input	The fraction critical speed of the original and simulated ball mills.
WorkIndex	Input	Bond Ball Work Index of ore in the original mill.
BallTopSize	Input	Diameter of new balls added to the original and simulated ball mills.
MaxBreakageRateFactor / K	Input	Parameter relating ball size and the size at which the breakage rate per discharge rate is maximum.
R/DFunction
NumSplineKnots	Input	Number of spline knots for the ${\frac {R}{D^{*}}}$ function.
Size	Input	Spline knot size positions.
Ln(R/D*)	Input	Values of $\ln {\frac {R}{D^{*}}}$ at each spline knot position.
Power
BallVolume	Input	Volumetric fraction of mill occupied by balls and voids.
VoidFillFraction	Input	Volumetric fraction of void space between balls occupied by slurry.
BallSG	Input	Specific Gravity or density of ball media.
Results
MillVolume	Display	Volume inside mill, including cones.
MillSpeed	Display	Rotational speed of simulated mill.
ChargeDensity	Display	Density of charge in simulated mill, including balls, solids and liquids.
NoLoadPower	Display	Power draw of empty mill (no balls, solids or liquids)
GrossPower.Grate	Display	Gross power draw of mill in grate configuration
GrossPower.Overflow	Display	Gross power draw of mill in overflow configuration

Ore page

This page is used to define the comminution properties of SysCAD species with the size distribution quality in the project.

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
Distribution
Name	Display	Shows the name of the SysCAD Size Distribution (PSD) quality associated with the feed stream.
IntervalCount	Display	Shows the number of size intervals in the SysCAD Size Distribution (PSD) quality associated with the feed stream.
SpWithPSDCount	Display	Shows the number of species in the feed stream assigned with the SysCAD Size Distribution (PSD) quality.
Appearance
OreSpecific	CheckBox	Ore-specific parameters, allows the Appearance data to be separately input for all species. Default is all species have the same set of single input properties.
DefaultAppearance		Sets all species to the the default Broadbent-Callcott Appearance function.
Appearance	Input	User-specified Appearance function data for all species with size distribution property.
WorkIndex
WorkIndex.Sim	Input	Bond Ball Work Index data for all species with size distribution property.

Ri/Di page

This page displays the scaling factors and breakage rate per discharge rate for each size interval computed by the Perfect Mixing model.

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
Scaling
RDStar/RD	Display	Value of the ${\frac {R}{D*}}{\bigg /}{\frac {R}{D}}$ factor for discharge rate scaling.
Diameter	Display	Value of the mill diameter factor for rate scaling.
LoadFraction	Display	Value of the load fraction factor for rate scaling.
FracCS	Display	Value of the fraction critical speed factor for rate scaling.
WorkIndex	Display	Valuex of the Work Index factor of each ore species for rate scaling.
Ri/DiStar
Size	Display	Size of each interval in internal mesh series.
MeanSize	Display	Geometric mean size of each interval in internal mesh series.
Ri/DiStar	Display	Value of normalised ${\frac {R_{i}}{D_{i}^{*}}}$ rate for each size interval, for each ore species.
Ri/Di
Size	Display	Size of each interval in internal mesh series.
MeanSize	Display	Geometric mean size of each interval in internal mesh series.
Ri/DiStar	Display	Value of ${\frac {R_{i}}{D_{i}}}$ rate for each size interval, for each ore species.

Power page

This optional page displays the inputs and results for alternative tumbling mill power models. The page is only visible if PowerModels is selected on the Scd*BallMill page.

Main article: Tumbling Mill (Power)

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
Power
HoggFuerstenau	CheckBox	Shows inputs and results for tumbling mill power calculations using the Hogg & Fuerstenau method. See Tumbling Mill (Power)#Hogg & Fuerstenau
MorrellE	CheckBox	Shows inputs and results for tumbling mill power calculations using the Morrell Empirical method. See Tumbling Mill (Power)#Morrell Empirical
MorrellC	CheckBox	Shows inputs and results for tumbling mill power calculations using the Morrell Continuum method. See Tumbling Mill (Power)#Morrell Continuum
MorrellD	CheckBox	Shows inputs and results for tumbling mill power calculations using the Morrell Discrete Shell method. See Tumbling Mill (Power)#Morrell Discrete Shell

MediaTraj page

This page displays the inputs and results for tumbling mill media trajectory calculations. The page is only visible if MediaTraj is selected on the Scd*BallMill page.

Main article: Tumbling Mill (Media Trajectory)

Overfilling page

This page displays the inputs and results for mill overfilling calculations. The page is only visible if Overfilling is selected on the Scd*BallMill page.

Main article: Ball Mill (Overfilling)

About page

This page is provides product and licensing information about the Met Dynamics Models SysCAD Add-On.

Tag (Long/Short)	Input / Display	Description/Calculated Variables/Options
About
HelpLink		Opens a link to the Installation and Licensing page using the system default web browser. Note: Internet access is required.
Information		Copies Product and License information to the Windows clipboard.
Product
Name	Display	Met Dynamics software product name
Version	Display	Met Dynamics software product version number.
BuildDate	Display	Build date and time of the Met Dynamics Models SysCAD Add-On.
License
File		This is used to locate a Met Dynamics software license file.
Location	Display	Type of Met Dynamics software license or file name and path of license file.
SiteCode	Display	Unique machine identifier for license authorisation.
ReqdAuth	Display	Authorisation level required, MD-SysCAD Full or MD-SysCAD Runtime.
Status	Display	License status, LICENSE_OK indicates a valid license, other messages report licensing errors.
IssuedTo	Display	Only visible if Met Dynamics license file is used. Name of organisation/seat the license is authorised to.
ExpiryDate	Display	Only visible if Met Dynamics license file is used. License expiry date.
DaysLeft	Display	Only visible if Met Dynamics license file is used. Days left before the license expires.