The effect of test parameters on large particle slurry erosion testing


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Latest study about effects of testing parameters with high speed slurry-pot wear tester. Parameters as speed, particle size and slurry concentration were tested. Study was presented at ITS 2013 symposium.
More information about the tester at Tampere Wear Center:

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The effect of test parameters on large particle slurry erosion testing

  1. 1. The effect of test parameterson large particle slurryerosion testingNiko Ojala1*, Kati Valtonen1, Pekka Siitonen2 and Veli-Tapani Kuokkala11 Tampere University of Technology, Department of Materials Science,Tampere Wear Center, P.O.Box 589, FI-33101 Tampere, Finland2 Metso Minerals, Inc., Tampere, Finland*email: niko.ojala@tut.fiITS 2013Luleå, Sweden19th – 21st March 2013
  2. 2. Motivation• In mining slurry handlingoperations particle sizescan be up to severalcentimeters [1][1] Basics in Minerals Processing, 6th ed., Metso Minerals, 2008[upper figure][lower figure]• But the slurry wearresearch have beenoften done with under 1mm particles
  3. 3. Overview to topics1) The equipment2) The testing program3) The results
  4. 4. High speed slurry-pot tester [2]• Samples in the pin mill configuration– Four sample levels– Both half- and full-lengthsamples were used– Sample rotation[2] Ojala, N et al., High Speed Slurry-Pot TypeErosion Wear Tester, The 15th Nordic Symposium onTribology - NordTrib 2012.time [min]0-5 L1 L2 L3 L45-10 L4 L1 L2 L310-15 L3 L4 L1 L215-20 L2 L3 L4 L1One or two samples on one levelSample levels
  5. 5. Three main parameters weretested separately• Sample speed• Particle size• Slurry concentration (total weight of the 8/10 mm abrasives)main shaft sample tip size weightSpeed1 1000 rpm 10 m/s 8/10 mm 1 kg 9 wt% halfSpeed2 1500 rpm 15 m/s 8/10 mm 1 kg 9 wt% halfSpeed3 2000 rpm 20 m/s 8/10 mm 1 kg 9 wt% halfSize1 2000 rpm 20 m/s 4/6.3 mm 1 kg 9 wt% fullSize2 2000 rpm 20 m/s 6.3/8 mm 1 kg 9 wt% fullSize3 2000 rpm 20 m/s 8/10 mm 1 kg 9 wt% fullWeight1 2000 rpm 20 m/s 8/10 mm 1 kg 9 wt% halfWeight2 2000 rpm 20 m/s 8/10 mm 2 kg 16 wt% halfWeight3 1950 rpm 20 m/s 8/10 mm 3 kg 23 wt% halfSpeed of Abrasive SlurryconcentrationSamplelengthTest ID
  6. 6. 01020304050600 10 20 30 40Massloss/numberofrotations[µg]Sample tip speed [m/s]Mass loss per number of rotations1 kg 8/10 mm granite, 10 l water, samesamplesSample speed• Higher speed meanshigher mass loss, ingeneral• With the largenatural abrasives,the kinetic energycompetes with thecomminution of theabrasives
  7. 7. 050010001500200025003000350040000 2 4 6 8 10Massloss/initialparticlecount[µg]Average original particle size [mm]Mass loss per particle amount2000 rpm, 1 kg granite, 10 l water,same samplesParticle size• Larger particles inducemore mass loss due to– Higher kineticenergy– Durability ofcomminution2.90 2.943.1300.511.522.533.54/6.3 mm 6.3/8 mm 8/10 mmAveragemassloss[g]
  8. 8. 00.511.522.533.544.550.00 % 10.00 % 20.00 % 30.00 %Massloss[g]Slurry concentration [wt%]Effect of slurry concentration2000 rpm, 8/10 mm granite, 10 lwater, same samplesSlurry concentration• Higher concentration induce more total mass loss due tolarger amount of particles• But with high concentrations, particle to particlecollisions and embedding of the particles increase andstart to decrease the mass loss050010001500200025000.00 % 10.00 % 20.00 % 30.00 %Massloss/initialparticlecount[µg]Slurry concentration [wt%]
  9. 9. Wear surfaceSample tips after the tests with23 wt% (left) and 16 wt% (right).Wear surface after the test with the23 wt% concentration
  10. 10. Wear surfaceShort wear scars after 23wt% testEmbedded granite particle after 23wt% test
  11. 11. Concluding remarks• With large abrasives, the particles kineticenergy competes with the comminution ofthe particles.• Larger particles have more kinetic energyand they endure comminution longer, causingmore mass loss by impact-abrasion.• With higher slurry concentration protectivemechanisms as particle-particle interactionand increasing particle embedding reducethe mass loss.
  12. 12. Thank you for your attention!Questions?Niko OjalaResearch ScientistTampere University of TechnologyDepartment of Materials Science, Tampere Wear CenterP.O.Box 589, FI-33101 Tampere, Finlandphone: +358 50 317 4516email: niko.ojala@tut.fiAcknowledgements