TM Technology IsaMill in the Primary Grinding Circuit G Anderson - PowerPoint PPT Presentation

TM Technology IsaMill in the Primary Grinding Circuit G Anderson (Xstrata Technology) D Smith (McArthur River Mining) S Strohmayr (McArthur River Mining)

TM Development - UFG IsaMill • Developed to address ultra fine grinding requirem ents for McArthur River and Mt I sa Pb/ Zn deposits • McArthur River required 7 µm grind • Conventional technology w as unsuitable due to poor efficiency and surface contam ination • Looked outside of the m ining industry • Collaboration w ith Netzsch of Germ any – history of m anufacturing stirred m ills for paint, inks, pharm aceuticals • 1 .1 MW M3 0 0 0 ( litre) I saMill™ developed – becam e the enabling technology for McArthur River Mine 1 9 9 5

TM Development - UFG IsaMill

TM Development – Coarse Grind IsaMill • Requirem ent for larger scale I saMill™ identified by Anglo • Inert and efficient grinding to improve mineral liberation and recovery • M1 0 ,0 0 0 I saMill™ developm ent w ith Anglo/ Netzsch 2 0 0 3 1 st M1 0 ,0 0 0 in UFG at W estern Lim b Tailings Retreatm ent • • Developm ent of 3 .5 m m ceram ic m edia w ith Magotteaux • 1 8 x 3 MW M1 0 ,0 0 0 I saMills™ installed w ithin Anglo • F8 0 of 7 5 -1 0 0 µm ; P8 0 of 5 3 µm • Further 4 x 3 MW on order for Anglo • W orldw ide over 1 0 0 I saMills™

TM Development – Coarse Grind IsaMill

TM Operation IsaMill

McArthur River - 2006 Flotation Primary Cyclones Verti Mill Ore stockpile Feeder SAG Mill Screen

McArthur River – Plant Trial • Plant trial com m enced in May 2 0 0 7 Flotation Magnetic Primary Cyclones Separator Verti Mill Ore stockpile Feeder 1.1MW IsaMill SAG Mill Screen

IsaMill™ Survey Data 100 Net Energy (kWhr/t) 10 M20 Testwork Predicted Full Scale >300um Feed 150-200um Feed 200 - 250um Feed 250-300um Feed 1 55-60 10 100 P80 Size (microns)

Effect of Media Size P98 110µm P98 220µm 100% 90% 80% 70% Cumulative % Passing 60% 50% 40% Feed 5-6mm Media 11kWhr/t 30% Product 5-6mm Media Feed 3.5mm Media 20% 16kWhr/t Product 3.5mm Media 10% 0% 10 100 1000 Size (um) P80 37µm

F80 350µm @ 12.8kWhr/ t 100% 90% Cumulative % Passing 80% 70% 60% 50% Feed 40% Discharge 30% 20% 10% 0% 10 100 1000 45 350 Size (um)

IsaMill™ Wear Performance • I nitial 4 0 0 hour service life • Disc and shell replacem ent • Still beneficial to operate - trial becam e perm anent production m ill • UFG m ills 2 0 0 0 hour service intervals • Higher w ear a function of • coarser feed/ media size • mineralogy • mill geometry designed for UFG

IsaMill™ Wear Performance • Sm aller Diam eter Discs : 1 2 0 0 m m to 1 0 5 0 m m • Service life increased 4 0 0 to 1 2 0 0 hours 0.025 0.02 Discs / MWh 0.015 0.01 0.005 0 1200mm Discs 1050mm Discs Mill Configuration • Max pow er reduced from 1 MW to 6 5 0 -7 0 0 kW • Proportionally lim ited the throughput to m aintain grind perform ance

McArthur M10,000 IsaMills™ • Successful M3 0 0 0 trial – perm anent production m ill • 2 x M1 0 ,0 0 0 installed for plant expansion Nov 2 0 0 8 • M3 0 0 0 developm ent w ork continued • M1 0 ,0 0 0 com m issioned in UFG circuit - allow ed 2 x M3 0 0 0 for prim ary grinding circuit

Primary Circuit Performance • Plant throughput increased by 2 5 % from 2 6 0 to 3 2 5 tph • W ith no I saMill™ case, P8 0 8 5 µm , OW i = 1 9 .3 kW hr/ t • W ith 2 x I saMill™ case, P8 0 7 6 µm , OW i = 1 8 .4 kW hr/ t

Development • I saMill™ Developm ent • Alternative disc designs and configurations to recover power draw • Shell design – M5000 IsaMill™ - can be retrofit to M3000 IsaMill™ • Allow geometrical ratios established with SDD in M3000 to be scaled up • Circuit Developm ent • McArthur River Phase 3 Development 2014 • Increase capacity to 5 mtpa • M10,000 included in study for upgraded primary circuit • Secondary or tertiary duty ahead of flotation

Conclusions • Successful lab, pilot and full scale testw ork • I saMill™ now integral, perm anent part of prim ary grinding circuit - operating for over 4 years • I m provem ents m ade to w ear life and perform ance w ith further developm ent w ork ongoing • Success of the program • IsaMill™ permanent part of grinding circuit • 2 x M10,000 installation • Further IsaMills™ under consideration for the Phase 3 expansion of the primary grinding circuit