About ...Moly-Cop Tools, Version 3.0About the Media Charge_Wear_Rod Mills Spreadsheet ...

Moly-Cop Tools, Version 2.0About the Media Charge_Wear_Ball Mills Spreadsheet ...

&"Arial,Bold"&8Moly-Cop Tools&"Arial,Regular" / &F&8&D / &T

Scope :

The Media Charge_Linear Wear_Rod Mills spreadsheet was designed to estimate the Linear Wear Rate Constants for a rod charge in a Conventional Rod Mill, as a function of its known dimensions and basic operating conditions. Also, the spreadsheet allows for the calculation of the typical Rod Consumption Rate indicators; that is, gr/ton, gr/kWh, kg/hr or tons/month.

Theoretical Framework :

See Media Charge_Wear Ball Mills.Data Input :

All data required by the model must be defined in each corresponding unprotected white background cell of the here attached Data File worksheet. Gray background cells contain the results of the corresponding formulas there defined and are protected to avoid any accidental editing.

Data_File

Moly-Cop Tools TM (Version 3.0)DETERMINATION OF WEAR RATE CONSTANTSSpecial Case : ROD MILLS

Remarks Base Case Example

Power, kWMill Dimensions and Operating Conditions1,205
Jaime E. Seplveda J.: See spreadsheet Mill Power_Ball Mills for details. RodsDiameterLengthMill SpeedChargeRodsInterstitialLift0
Jaime E. Seplveda J.: See spreadsheet Mill Power_Ball Mills for details. Overfillingftft% CriticalFilling,%Filling,%Slurry Filling,%Angle, ()145
Jaime E. Seplveda J.: See spreadsheet Mill Power_Ball Mills for details. Slurry15.50
Jaime E. Seplveda J.: Mill Diameter, inside liners.20.00
Jaime E. Seplveda J.: Effective Grinding Lenght.72.00
Jaime E. Seplveda J.: Rotational Mill Speed, expressed as a percentage of the critical centrifugation speed of the mill.30.00
Jaime E. Seplveda J.: Total Apparent Volumetric Charge Filling - including balls and excess slurry on top of the ball charge, plus the interstitial voids in between the balls - expressed as a percentage of the net internal mill volume (inside liners).30.00
Jaime E. Seplveda J.: In some cases - particularly with Overflow Discharge Mills operating at low ball fillings - slurry may accumulate on top of the ball charge; therefore, the Total Charge Filling Level (Cell F13) could be higher than the actual Ball Filling Level (Cell G13).100.00
Jaime E. Seplveda J.: This value represents the Volumetric Fractional Filling of the Voids in between the balls by the retained slurry in the mill charge.As defined, this value should never exceed 100%, but in some cases - particularly in Grate Discharge Mills - it could be lower than 100%.Note that this interstitial slurry does not include the overfilling slurry derived from the difference between Cells F13 and G13.19.61
Jaime E. Seplveda J.: Represents the so-called Dynamic Angle of Repose (or Lift Angle) adopted during steady operation by the top surface of the mill charge ("the kidney") with respect to the horizontal. A reasonable value for this angle is 30- 35.1,350
Jaime E. Seplveda J.: See spreadsheet Mill Power_Ball Mills for details. Net Totalrpm 14.0110.00 % Losses % Utilization hr/month1,500 Gross Total% Solids in the Mill72.0097.006981,048 MWh/monthOre Density, ton/m34.00Slurry Density, ton/m32.17ChargeMill Charge Weight, tonsApparentRods Density, ton/m37.75Volume,RodSlurryDensitym3ChargeInterstitialabove Rodston/m3Ore Feedrate, ton/hr350.032.12174.2620.950.006.077 ton/day8,148Energy, kWh/ton (ore)4.29Rod Recharge Rategr/tongr/kWh (gross)gr/kWh (rods)Kg/hrtons/monthMake-up Rod Size, mm100.0500.0
Jaime E. Seplveda J.: To set this cell equal to any actual measured value, use Tools / Goal Seek, by changing Cell J28.116.67
Jaime E. Seplveda J.: To set this cell equal to any actual measured value, use Tools / Goal Seek, by changing Cell J28.145.21175.0
Jaime E. Seplveda J.: To set this cell equal to any actual measured value, use Tools / Goal Seek, by changing Cell J28.122
Jaime E. Seplveda J.: To set this cell equal to any actual measured value, use Tools / Goal Seek, by changing Cell J28.Scrap Size, mm40.0Wear Rate Constants:Spec. Area, m2/m3 (app)50.26 kdE, mm/[kWh(rods)/ton(rods)]5.394Total Charge Area, m21614 kd, mm/hr0.0373

Purge Time, hrs1,609

&"Arial,Bold"&8Moly-Cop Tools&"Arial,Regular" / &F&8&D / &T