HPGR (Campos)

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Revision as of 04:18, 15 December 2023 by imported>Scott.Munro (→‎Inputs)
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Description

This article describes the Campos (Campos et al., 2021) model for comminution by High Pressure Grinding Rolls (HPGR), which is based on Torres and Casali's (2009) approach.[1][2]

Model theory

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Excel

The Campos HPGR model may be invoked from the Excel formula bar with the following function call:

=mdUnit_HPGR_Campos(Parameters as Range, Size as Range, HPGRFeed as Range, OreSG as Range, Selection as Range, Breakage as Range)

Invoking the function with no arguments will print Help text associated with the model, including a link to this page.

Inputs

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




where:

  • is the selection function method, 0 = User, 1 = Herbst-Fuerstenau, 2 = Austin
  • is the breakage function method, 0 = User, 1 = Austin & Luckie, 2 = King, 3 = Natural selection
  • is the diameter of the rolls (m)
  • is the length of the rolls (m)
  • is the operating pressure of the rolls (bar)
  • is the bulk density of the feed solids (t/m3)
  • is the ratio of cake bulk density to solids phase density (frac)
  • is the edge fraction (frac)
  • is the fraction of the interparticle compression angle applied to compute power draw (deg/deg)
  • is the number of model blocks
  • is the stud penetration depth (m)
  • is the maximum rolls velocity (m/s)
  • is the autogenous layer surface fraction (m2/m2)
  • is a throughput parameter (-)
  • is a throughput parameter (-)
  • is a throughput parameter (-)
  • is the power shape factor (-)
  • is an energy utilisation parameter (kWh/t)
  • is an energy utilisation parameter (-)
  • is the number of size intervals
  • is the number of ore types
  • is the size of the square mesh interval that mass is retained on (mm)
  • , i.e. descending size order from top size () to sub mesh ( mm)
  • is feed solids mass flow rate by size and ore type (t/h)
  • is the solid density (t/m3)
  • is the value of the energy-specific selection function () at a nominal reference particle size (mm)
  • and are coefficients that characterise the shape of the energy-specific selection function curve
  • , , , and are coefficients that determine the shape of the cumulative breakage function curve

Results

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

where:

  • is the bulk density of discharge cake solids (t/m3)
  • is the critical gap (m)
  • is the interparticle compression angle (deg.)
  • is the throughput (t/h)
  • is the circumferential rolls speed (m/s)
  • is the rotational speed of the rolls (rpm)
  • is the specific throughput (t.s/m3.h)
  • is the compression force (kN)
  • is the specific comminution energy (kWh/t)
  • is power draw (kW)
  • is the operating gap (m)
  • is the material velocity (m)
  • is the feed ejection fraction (frac)
  • is the energy utilisation fraction (frac)
  • is the mass flow rate of particles in the overall, combined product (t/h)
  • is the mass flow rate of particles in the edge product (t/h)
  • is the mass flow rate of particles in the centre product (t/h)
  • is the geometric mean size of particles in size interval (mm)
  • is the energy-specific selection function
  • is the cumulative breakage function (frac)
  • is block position (m)

Example

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

Figure 1. Example showing the selection of the Parameters (blue frame) array in Excel.
Figure 2. Example showing the selection of the Size (red frame), HPGRFeed (purple frame) and OreSG (green frame) arrays in Excel.
Figure 3. Example showing the selection of the Selection (pink frame) and Breakage (brown frame) arrays in Excel.
Figure 4. Example showing the outline of the Results (light blue frame) array in Excel.

SysCAD

The sections and variable names used in the SysCAD interface are described in detail in the following tables.

MD_HPGR 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 crusher with no change to the size distribution.
Method Fixed Discharge The discharge particle size distribution is user defined. Different distributions can be used for different solids.
Morrell-Shi-Tondo The throughput, power draw and product size distribution are determined by the Morrell-Tondo-Shi model. Different parameters can be used for different solids.
Torres The throughput, power draw and product size distribution are determined by the Torres model. Different parameters can be used for different solids.
Campos The throughput, power draw and product size distribution are determined by the Campos model. Different parameters can be used for different solids.
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.
SizeForPassingFracCalc Input Size fraction for % Passing calculation. The size fraction input here will be shown in the Stream Summary section.
FracForPassingSizeCalc Input 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.

HPGR page

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

Tag (Long/Short) Input / Display Description/Calculated Variables/Options
HerbstFuerstenau
HelpLink ButtonModelHelp.png Opens a link to this page using the system default web browser. Note: Internet access is required.
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.
Parameters
RollDiameter / D Input Diameter of the rolls.
RollLength / L Input Length of the rolls.
OperatingPressure / Rp Input Operating pressure of the rolls.
FeedBulkDensity / Rhoa Input Bulk density of solids in the feed.
CakeDensityFactor Input Cake density factor.
EdgeFraction / a Input Fraction of the product collected from the edge of the rolls length, appearing in the edge product stream.
NumBlocks / Nb Input Number of model blocks, i.e. instances of the Herbst-Fuerstenau mill model along the length of the rolls.
Selection
Method User The user specifies the selection function.
Herbst and Fuerstenau The Herbst and Fuerstenau selection function is used.
Austin The Austin selection function is used.
OreSpecific CheckBox Ore-specific parameters, allows the selection function to be separately input for all species. Default is all species have the same set of single input properties.
This option is only available if there is more than one species in the project with the size distribution property.
The fields below are only visible if Herbst-Fuerstenau is selected.
S1E Input Input parameter of the Herbst-Fuerstenau selection function.
Zeta1 Input Input parameter of the Herbst-Fuerstenau selection function.
Zeta2 Input Input parameter of the Herbst-Fuerstenau selection function.
dp1 Input Input parameter of the Herbst-Fuerstenau selection function.

MillHerbstFuerstenau5.png MillHerbstFuerstenau6.png

The fields below are only visible if Austin is selected.
Alpha0 Input Input parameter of the Austin selection function.
Alpha1 Input Input parameter of the Austin selection function.
Alpha2 Input Input parameter of the Austin selection function.
dCrit Input Input parameter of the Austin selection function.
Alpha02 Input Input parameter of the Austin selection function.
Alpha12 Input Input parameter of the Austin selection function.

MillHerbstFuerstenau7.png MillHerbstFuerstenau8.png

Breakage
Method User The user specifies the breakage function.
Austin and Luckie The Austin and Luckie breakage function is used.
King The King selection function is used.
Natural Selection The Natural selection function is used.
OreSpecific CheckBox Ore-specific parameters, allows the breakage function to be separately input for all species. Default is all species have the same set of single input properties.
This option is only available if there is more than one species in the project with the size distribution property.
The fields below are only visible if Austin and Luckie is selected.
Beta0 Input Input parameter of the Austin and Luckie breakage function.
Beta1 Input Input parameter of the Austin and Luckie breakage function.
Beta2 Input Input parameter of the Austin and Luckie breakage function.
Beta01 Input Input parameter of the Austin and Luckie breakage function.

MillHerbstFuerstenau9.png MillHerbstFuerstenau10.png

The fields below are only visible if King is selected.
K Input Input parameter of the King breakage function.
n1 Input Input parameter of the King breakage function.
n2 Input Input parameter of the King breakage function.
n3 Input Input parameter of the King breakage function.
y0 Input Input parameter of the King breakage function.

MillHerbstFuerstenau11.png MillHerbstFuerstenau12.png

Results
CriticalSize / xc Display Critical size.
InterparComprAngle / alphaIP Display Interparticle compression angle.
Throughput / Gs Display Solids mass throughput flow rate of the HPGR.
RollsVelocity / U Display Circumferential velocity of the rolls.
RollsSpeed Display Rotational speed of the rolls.
SpecificThroughput / mDot Display Specific throughput parameter of the HPGR unit.
CompressionForce / F Display Compression force of the rolls.
GrossPower / P Display Gross power draw of the HPGR unit
SpecificEnergy / W Display Specific energy of grinding.

Selection page

The Selection page is used to specify or display the selection function values.

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.
Selection
Size Display Size of each interval in mesh series.
MeanSize Display Geometric mean size of each interval in mesh series.
Selection Input/Display Value of the selection function for each size interval, for each ore species.

Breakage page

The Breakage page is used to specify or display the breakage function values.

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.
Breakage
Size Display Size of each interval in internal mesh series.
Breakage Input/Display Value of the breakage function for each parent size interval, progeny size interval and ore species.

Power page

The Power page is used to display power draw of model blocks along the length of the rolls.

Tag (Long/Short) Input / Display Description/Calculated Variables/Options
Power
Position / y Display Position along the rolls length.
Power / Pk Display Power draw of model block at position along the rolls length.
UtilPower / PsiPk Display Utilised power draw of model block at position along the rolls length.

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 ButtonLicensingHelp.png Opens a link to the Installation and Licensing page using the system default web browser. Note: Internet access is required.
Information ButtonCopyToClipboard.png 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 ButtonBrowse.png 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.

Additional notes

When the edge stream is connected, the following applies to mass splits:

  • Solid species without a particle size distribution property are split to the edge stream according to the overall mass split of the default particle size distribution species selected in the SysCAD Project Configuration
  • If the default particle size distribution species is not present in the unit feed, the overall split of all other species with particle size distributions combined is used, as determined by the model.
  • Liquids species are split between the edge and product streams in the same proportion as solid species.
  • Gas phase species report directly to the product stream without split.

See also

References

  1. Campos, T.M., Bueno, G. and Tavares, L.M., 2021. Modeling comminution of iron ore concentrates in industrial-scale HPGR. Powder Technology, 383, pp.244-255.
  2. Torres, M. and Casali, A., 2009. A novel approach for the modelling of high-pressure grinding rolls. Minerals Engineering, 22(13), pp.1137-1146.