Ball MillBall Mill Performance & EfficiencyS.DescriptionSymbolFormulaExampleNo.1Arm of gravitya0.666 * ( 1 - 4 * R2 )1.5h0.583-TAN-1 [ 0.5 / R * (1 - 4*R2)0.5] - [ 2*R * (1 - 4*R2)0.5 ]Deff4.18hCentre Distance (from mill centre to media top layer), mtsR0.139DeffMill effective diameter, mtsa0.578Rh/Deff, ratio of centre distance to mill effective diameterTarget-2Torque factor matrixu---------------------2Power consumption, netPn0.514 * F * u * n * Deff * aF175kWFGrinding media weight, tonsu0.73uTorque factorn16nMill speed, rpmDeff4.18DeffMill effective diameter, mtsa0.578aArm of gravity, -Pn2538Target-3Power consumption, grossPgPn * 100 * 100Pn2450kWEm * EgEm95EmMotor efficiency, %Eg95EgGearbox/girth gear efficiency, %Pg2715Target-4New production rateNPBFormula-1OPB118(Mill output Vs. Blaine)tphOPBOB4000Exp ( ( NB - OB ) * 0.49 / 1000 )NB5000OPBOld production rate, tphNPB72OBOld blaine, cm2/gmTarget-NBNew blaine, cm2/gmFormula-2OPB118OPB * ( OB / NB )1.3OB4000OPBOld production rate, tphNB5000OBOld blaine, cm2/gmNPB88NBNew blaine, cm2/gmTarget-5New production rateNPROPR * ( 2 - log ( OR ) )OPR150(Mill output Vs. Residue)tph( 2 - log ( NR ) )OR11.5OPROld production rate, tphNR9.5OROld residue, %NPR138NRNew residue, %Target-6Gypsum set pointGSP21500 * ( Scem - Sclk )Scem2.1(at weigh feeder)tphPu * ( 100 - Fgyp )Pu90ScemTarget SO3 content in cement, %Sclk0.3PuGypsum purity, %Fgyp4.8SclkSO3 content in clinker, %GSP4.52FgypFree moisture in gypsum, %Target-7Maximum ball sizeMBS36 * F0.5 * { ( SG * Wi ) / ( %C * Deff0.5 ) }0.333F15mmFFeed size (sieve size in mm which retains 20% material), mmSG3SGSpecific weight of feed material, gm/cm3Wi15WiBond's work index, kWh/t%C75%CMill speed as %critical, %Deff5.1DeffMill effective diameter, mtsMBS90Target-8%Filling%F112.5 - ( 125 * h / Deff )h2.5%hFree height, mtsDeff4.155DeffMill effective diameter, mts%F37.3Target-9Circulation factorCFormula-1FF150-F + GCR170FC2.13FFresh feed rate, tphTarget2-3GCoarse return, tphFormula-2Rg54.92Rg - RfRf3.52Rg - RmRm34.16RgResidue of coarse return, %C2.48RfResidue of fines, %Target2-3RmResidue of separator feed, %10Circulation loadCL( C - 1 ) * 100C2.48%CCirculation factor, -CL148Target-11Separator efficiencySEFormula-1Ro100%[log(Ro/Rf) - C * log[{Ro+(C-1)*Rg} / {Rf+(C-1)*Rg}]]*100Rf3.52log(Ro/Rf) - C * log[{Ro+(C-1)*100} / {Rf+(C-1)*100}]C2.48RoResidue of fresh feed, %Rg54.92RfResidue of fines, %SE68.8CCirculation factor, -Target70-80RgResidue of coarse return, %Formula-2 (Fines Efficiency)Rf3.52( 100 - Rf ) * 100Rm34.16( 100 - Rm ) * CC2.48RfResidue of fines, %SEf59.1RmResidue of separator feed, %Target70-80CCirculation factor, -Formula-3 (Coarse Efficiency)Rg54.92Rg * ( C - 1 ) * 100C2.48C * RmRm34.16RgResidue of coarse return, %SEc95.9CCirculation factor, -Target70-80RmResidue of separator feed, %12Critical speednc42.3 / Deff0.5Deff4.15rpmDeffMill effective diameter, mtsPn20.8Target-1New production rateNPRFormula-1OPB118(Mill output Vs. Blaine)tphOPBOB4000100Exp ( ( NB - OB ) * 0.49 / 1000 )NB50003000OPBOld production rate, tphNPR723500OBOld blaine, cm2/gm1.221NBNew blaine, cm2/gmFormula-2OPB118OPB * ( OB / NB )1.3OB4000OPBOld production rate, tphNB5000OBOld blaine, cm2/gmNPR88NBNew blaine, cm2/gm2New Specific power cons.Formula(sp. power Vs. Blaine)NPRE1E (S1 / S)nkWh/TCE1New specific powerE32.5EOld specific powerS15000S1New BlaineS4000SOld Blainen1.3nMill exponent for close ckt = 1.3E143.441New production rateNPRFormulaOPB118(Mill output Vs. Blaine)tphOPB * ( OB / NB )1.3OB4000OPBOld production rate, tphNB5000OBOld blaine, cm2/gmNPR88NBNew blaine, cm2/gm2New Specific power cons.Formula(sp. power Vs. Blaine)NPRE1E (S1 / S)nkWh/TCE1New specific powerE32.5EOld specific powerS15000S1New BlaineS4000SOld Blainen1.3nMill exponent for close ckt = 1.3E143.44

&CAmbuja Cement Rajasthan Limited

MBD001821CD.xlsSheet1

MaterialGrindingFittingTypeTorque

Cement & Raw MealCoarse/MediumNoneBalls0.73

NoneRods0.55

DanulaBalls0.75

SonexBalls0.66

FineNoneBalls0.69

NoneCylpebs0.73

DanulaBalls0.71

DanulaCylpebs0.75

CoalCoarse/MediumNoneBalls/Cylpebs0.69

MediumDanulaCylpebs0.71

Sheet2

Sheet3