Basics in Mineral Processing PDF

Basics in Basics Minerals in Processing Minerals Processing Edition 12  Contents 1. Introduction 12 1.1 Basic definitions 12 1.2 Minerals by value...

Basics in Basics Minerals in Processing Minerals Processing Edition 12  Contents 1. Introduction 12 1.1 Basic definitions 12 1.2 Minerals by value 13 1.3 The process frame of minerals 14 1.4 Mineral processing and hardness 15 1.5 Size and hardness 15 1.6 The stress forces of rock mechanics 16 2. Minerals in operation 18 2.1 Operation stages 18 2.2 Operation – Dry or wet ? 18 2.3 Mining and quarry fronts 19 2.4 Natural fronts 19 2.5 Size reduction 21 2.6 Size control 22 2.7 Enrichment – Washing 22 2.8 Enrichment – Separation 23 2.9 Upgrading 23 2.10 Materials handling 24 2.11 Wear in operation 25 2.12 Operation and environment 26 2.13 Operation values 26 3. Size reduction 28 3.1 The size reduction process 28 3.2 Feed material 29 3.3 Reduction ratio 29 3.4 The art of crushing 30 3.5 Crushing of rock and gravel 30 3.6 Crushing of ore and minerals 31 3.7 Crushing – Calculation of reduction ratio 32 3.8 Selection of crushers 33 3.9 Primary crusher – Type 33 3.10 Primary crusher – Sizing 34 3.11 Secondary crusher – Type 35 3.12 Cone crusher – A powerful concept 35 3.13 Secondary crushers – Sizing 36 3.14 Final crushing stage – More than just crushing 38 3.15 VSI – A rock on rock autogeneous crushing impactor 38 3.16 High Pressure Grinding Rolls (HPGRs) - HRC™ 39 2 3.17 Final crusher – Sizing 40 3.18 Wet crushing prior to grinding* 41 3.19 Technical data: Gyratory crusher – SUPERIOR® MK-II Primary 42 3.20 Technical data: Jaw crusher – C series 43 3.21 Technical data: Impact crusher – NP series 44 3.22 Technical data: Cone crusher – GPS series 45 3.23 Technical data: Cone crusher – HPX00 series 46 3.24 Technical data: Cone crusher – HPX series 47 3.25 Technical data: Cone crusher – MP series 48 3.26 Technical data: Cone crusher – GP series 49 3.27 Technical data: Vertical shaft impactor (VSI) 50 3.28 High Pressure Grinding Rolls (HPGRs) - HRC™ 51 3.29 Grinding – Introduction 52 3.30 Grinding methods 52 3.31 Grinding mills – Reduction ratios 52 3.32 Grinding – Tumbling mills 53 3.33 Grinding – Stirred mills 55 3.34 Grinding – Vibrating mills 56 3.35 Cost of grinding – Typical 57 3.36 Mill linings and grinding media 57 3.37 Grinding mills – Sizing 58 3.38 Grinding circuits 58 3.39 VERTIMILL® Circuits 63 3.40 Stirred Media Detritors (SMD) Circuits 65 3.41 Grinding – Power calculation 67 3.42 Grinding – Bonds Work Index* 67 3.43 Pulverizing of coal 68 3.44 VERTIMILL® – More than a grinding mill 69 3.45 VERTIMILL® as lime slaker 70 3.46 Grinding vs enrichment and upgrading 70 3.47 Technical data: AG and SAG mills 71 3.48 Technical data: Ball mills 72 3.49 Technical data: Spherical roller bearing supported ball mill 74 3.50 Technical data: Conical ball mill 75 3.51 Technical data: SRR mill 76 3.52 Technical data: VERTIMILL® (wide body) 77 3.53 Technical data: VERTIMILL® 78 3.54 Technical data: VERTIMILL® (lime slaking) 79 3.55 Technical data: Stirred media grinding mIll 80 3.56 Technical data: Vibrating ball mill 80 3  4. Size control 82 4.1 Size control – Introduction 82 4.2 Size control by duties 82 4.3 Size control by methods 82 4.4 Screens 83 4.5 Screening by stratification 83 4.6 Screen types 84 4.7 Screen capacities 84 4.8 Selection of screening media 85 4.9 Particle size – Mesh or Micron? 86 4.10 Technical data: Single inclination screen – Circular motion 87 4.11 Technical data: Double inclination screen – Linear motion 88 4.12 Technical data: Triple inclination screen – Linear motion 89 4.13 Technical data: Multiple inclination screen – Linear motion (Banana screen) 89 4.14 Classification – Introduction 90 4.15 Wet classification – fundamentals 90 4.16 Hydrocyclone – Introduction 91 4.17 Hydrocyclone cluster 92 4.18 Technical data: Hydrocyclone 93 4.19 Spiral classifier* 94 4.20 Dry classification – Introduction 96 4.21 Static classifiers 96 4.22 Dynamic classifiers 99 4.23 Ancillary air solutions 99 4.24 Dry Grinding 101 4.25 Size control in crushing and grinding circuits 103 5. Enrichment 104 5.1 Enrichment – Introduction 104 5.2 Enrichment – Processes 104 5.3 Separation – Introduction 107 5.4 Separation by gravity 107 5.5 Separation in water 107 5.6 Separation by jigs* 108 5.7 Separation by spiral concentrators* 108 5.8 Separation by shaking tables* 108 5.9 Separation in dense media 109 5.10 Separation by flotation 110 5.11 Flotation circuit layout 111 5.12 Reactor cell flotation system (RCS) 112 5.13 Reactor cell system (RCS) – Sizing, metric 113 5.14 RCS specifications 115 5.15 Flotation machine – RCS 116 4 5.16 DR Flotation cell system 117 5.17 Technical data: Flotation machine – DR, Metric 118 5.18 Technical data: Flotation machine – DR, US 119 5.19 Column flotation cells system 120 5.20 Column flotation – Microcel sparger features 121 5.21 Magnetic separation – Introduction 122 5.22 Magnetic separation – Methods 123 5.23 Magnetic separation – Separator types 124 5.24 Magnetic separation equipment 124 5.25 Dry LIMS – Belt drum separator, BS 125 5.26 Technical data: Dry LIMS – Belt separator (BSA and BSS) 126 5.27 Dry LIMS – Drum separator, DS 127 5.28 Technical data: Dry LIMS – Drum separator – (DS) 128 5.29 Wet LIMS – Wet magnetic separators 129 5.30 Wet LIMS – Concurrent CC 129 5.31 Wet LIMS – Counter rotation CR and CRHG 130 5.32 Wet LIMS – Countercurrent CTC and CTCHG 130 5.33 Wet LIMS – Counter rotation froth DWHG 131 5.34 Technical data: Wet LIMS – Dense media recovery DM and DMHG 131 5.35 Technical data: Wet LIMS – Concurrent (CC) 132 5.36 Technical data: Wet LIMS – Counterrotation CR and CRHG 132 5.37 Technical data: Wet LIMS – Countercurrent CTC and CTCHG 133 5.38 Technical data: Wet LIMS – Counter rotation froth DWHG 133 5.39 Technical data: Wet LIMS – Dense media DM and DMHG 134 5.40 Wet HGMS/F – Magnet design 135 5.41 Wet HGMS, HGMF – Separator types 135 5.42 Wet cyclic HGMS 136 5.43 Wet cyclic HGMS – Process system 137 5.44 Wet cyclic HGMS – Operation 137 5.45 Wet cyclic HGMS – Applications 138 5.46 Wet cyclic HGMS – Sizing (indicative) 138 5.47 Technical data: Wet cyclic HGMS 139 5.48 Technical data: Wet cyclic high gradient magnetic filter HGMF 140 5.49 HGMF - Applications 142 5.50 HGMF – Process data 142 5.51 HGMF – Sizing 142 5.52 Technical data: Wet cyclic high gradient magnetic filter – HGMF 143 5.53 Wet continuous HGMS 144 5.54 Wet continuous HGMS – Process system 144 5.55 Wet continuous HGMS – Applications 144 5.56 Wet continuous HGMS – Sizing and selection 145 5.57 Technical data: Wet continuous HGMS 146 5.58 Leaching of metals 147 5  5.59 Gold leaching 148 5.60 Gold leaching – Carbon adsorption 148 5.61 Gold leaching – CIP 149 6. Upgrading 150 6.1 Upgrading – Introduction 150 6.2 Upgrading by methods 150 6.3 Upgrading by operation costs 150 6.4 Sedimentation 151 6.5 Flocculation 151 6.6 Conventional clarifier 152 6.7 Conventional clarifier – sizing 152 6.8 Conventional thickener 153 6.9 Conventional thickeners – Sizing 153 6.10 Conventional clarifier/thickener – Design* 154 6.11 Conventional clarifier/thickener* – Drive system 155 6.12 Conventional clarifier/thickener* drive – Sizing 156 6.13 Inclined plate sedimentation – Introduction 158 6.14 Inclined Plate Settler – IPS 160 6.15 Inclined Plate Settler – Drives 161 6.16 Inclined Plate Settler – Product range 162 6.17 Technical data: Inclined Plate Settler – LTO 165 6.18 Technical data: Inclined Plate Settler – LTS 166 6.19 Technical data: Inclined Plate Settler – LTK 167 6.20 Technical data: Inclined Plate Settler – LTE 168 6.21 Technical data: Inclined Plate Settler – LTE/C 169 6.22 Technical data: Inclined Plate Settler – LTC 170 6.23 Mechanical dewatering – Introduction 171 6.24 Mechanical dewatering – Methods and products 171 6.25 Gravimetric dewatering 172 6.26 Spiral dewaterer 172 6.27 Technical data: Spiral dewaterer 173 6.28 Sand screw* 174 6.29 Dewatering screen* 174 6.30 Dewatering wheel* 174 6.31 Mechanical dewatering by pressure – Introduction 175 6.32 Drum vacuum filters 175 6.33 Belt drum filter* 176 6.34 Top feed drum filter* 176 6.35 Vacuum filters – Vacuum requirement 177 6.36 Vacuum plant – Arrangement 177 6.37 Vertical plate pressure filter – Introduction 178 6.38 Vertical plate pressure filter – Design 179 6 6.39 Pressure filter VPA – Operation 179 6.40 Pressure filter VPA – Nomenclature 181 6.41 Pressure filter VPA – Technical data 181 6.42 Pressure filter VPA – Sizing 184 6.43 Pressure filter VPA - Moisture in filter cake 185 6.44 Pressure filter VPA - Typical air flows 185 6.45 Pressure filter VPA – Feed pump selection (guidance only) 185 6.46 Pressure filter VPA - Feed pump power (approximate) 185 6.47 Pressure filter VPA - Product system 186 6.48 Tube press – Introduction 187 6.49 Tube press – Design 188 6.50 Tube press – Operation 189 6.51 Tube press – Examples of applications 191 6.52 Tube press – Material of construction 192 6.53 Tube press – Sizes 192 6.54 Tube press – Sizing 192 6.55 Tube press – Cycle times and cake moisture 193 6.56 Tube press – Capacity 193 6.57 Tube press – Product systems 194 6.58 Tube press booster system 195 6.59 Mechanical description 196 6.60 Technical data: Tube press 197 6.61 Tube press booster 197 6.62 Thermal processing – Introduction 198 6.63 Direct heat rotary dryer (Cascade type) 199 6.64 Indirect heat rotary dryer (Kiln) 199 6.65 Fluidized bed 200 6.66 Indirect heat screw dryer (Holo-Flite®) 202 6.67 Holo-Flite® – Process system 202 6.68 Holo-Flite® System common sizes 204 6.69 Iron ore pelletizing 206 6.70 Typical pellet plant schematic 207 6.71 Grate Kiln technology 209 6.72 Major process equipment components of iron ore pellet plant 212 6.73 Design criteria and plant sizing 213 6.74 Comparisons of indurating technologies 214 6.75 Lime calcining system 215 6.76 Coke calcining system 217 6.77 Tire pyrolysis 218 7  7. Materials handling 220 7.1 Introduction 220 7.2 Loading and unloading 220 7.3 Railcar dumpers 220 7.4 Train positioners 221 7.5 Unloaders 222 7.6 Storage buffering 224 7.7 Stacker reclaimer 225 7.8 Scraper reclaimer 225 7.9 Barrel reclaimer for “Full cross section recovery” 226 7.10 Feeding 227 7.11 Technical data: Feeder – Apron 229 7.12 Technical data: Feeder – Vibration (linear motion) 230 7.13 Technical data: Feeders – Unbalanced motor 231 7.14 Technical data: Feeder – Belt 232 7.15 Technical data: Feeder – Electromagnetic 233 7.16 Technical data: Feeder – Wobbler 234 7.17 Conveying 235 7.18 Conveying systems 236 7.19 Conveyor capacities 237 7.20 Volume weight and angle of inclination 237 7.21 Conveyor – More than a rubber belt 238 7.22 Technical data: Conveyor – Standard belt 239 7.23 Vertical conveyor system 240 8. Slurry Handling 242 8.1 Slurry Handling – Introduction 242 8.2 Basic definitions 243 8.3 Technical description 246 8.4 Metso Outotec slurry pump series and sizes 247 8.5 Metso Outotec horizontal slurry pump wet-end modular configurations 248 8.6 Metso Outotec vertical slurry pump wet-end modular configurations 249 8.7 Slurry pump range MD 250 8.8 Slurry pump range XM 251 8.9 Dredge pumps 252 8.10 Slurry pump range VASA HD and XR 253 8.11 Slurry pump range HR and HM 254 8.12 Slurry pump range MR and MM 255 8.13 Slurry pump range VT 256 8.14 Slurry pump range VF 257 8.15 Slurry pump range VS 258 8.16 Slurry pump range VSHM, VSHR and VSMM 259 8.17 Application guide 260 8 8.18 Selection by solids 261 8.19 Duties realted to head and volume 261 8.20 Duties realted to slurry type 261 8.21 Selection of slurry pumps – by industrial application 262 8.22 Industrial segment:Construction 263 8.23 Industrial segment: Coal 263 8.24 Industrial segment:Waste & recycling 263 8.25 Industrial segment: power & FGD 263 8.26 Industrial segments:Pulp & paper 263 8.27 Industrial segment:Metallurgy 264 8.28 Industrial segment:Chemical 264 8.29 Industrial segment: Mining 264 8.30 Slurry transport 265 8.31 Slurry pipeline sizing 266 8.32 Wear 268 8.33 Accessories: 269 8.34 Slurry valves – Introduction 271 8.35 Slurry valves 273 9. Wear in operation 276 9.1 Wear in operation - Introduction 276 9.2 Wear in operation 276 9.3 Wear by compression 277 9.4 Wear by impaction (high) 277 9.5 Wear by impaction (low) 278 9.6 Wear by sliding 279 9.7 Wear protection – Wear lining and sheeting 280 9.8 Wear protection – Wear parts 282 9.9 Wear parts – Slurry pumps 290 9.10 Something about ceramic liners 291 9.11 Wear in slurry pipelines 292 10. Operation and environment 293 10.1 Operation and environment – Introduction 293 10.2 Dust 293 10.3 Dust control – Basic 294 10.4 Dust control – Basic 294 10.5 Noise 296 10.6 Noise reduction 297 10.7 Ear protection 299 9  11. Process system 300 11.1 Process system – Introduction 300 11.2 System modules – Aggregates 301 11.3 System modules – Sand and gravel 301 11.4 System modules – Ore and minerals 302 11.5 Process system – Railway ballast 303 11.6 Process systems – Asphalt / Concrete ballast 303 11.7 Process system – Ferrous ore (hosting apatite) 304 11.8 Process system – Base metal ore 304 11.9 Process system – Gold bearing ore 305 11.10 Process system – Coal 305 11.11 Process system – Industrial mineral fillers 306 11.12 Process system – Glass sand 306 11.13 Process system – Diamonds (Kimberlite) 307 11.14 Process system – Kaolin 307 11.15 Mobile systems 308 11.16 Primary jaw crusher + Grizzly (typical) 309 11.17 Primary impact crusher + Grizzly (typical) 309 11.18 Metso Outotec simulation tools 310 11.19 Consulting business 310 11.20 Process technology and innovation 310 12. Miscellaneous 311 12.1 Conversion factors 311 12.2 Tyler standard scale 312 12.3 Specific gravity 313 10 Metso Outotec mining and aggregates Brand names in minerals processing and aggregates Allis Chalmers (AC) McNally Wellman Allis Minerals System Neims Altairac NICO Armstrong Holland Nokia Barmac Nolan Bergeaud Nordberg Boliden Allis MPSI Cable Belt Orion Conrad Scholtz PECO Denver Pyrotherm Dominion Read FACO REDLER GFA Sala Hardinge Scamp Hewitt Robins Skega Kennedy Van Saun KVS Stansteel Kue-ken Seco Stephens – Adamson Koppers Strachan & Henshaw Lennings Svedala Lokomo Thomas Marcy Tidco Masterscreens Trellex McDowell Wellman Tyler 11  Introduction 12 1. Introduction “The practice of minerals processing is as old as human civilization. Minerals and products derived from minerals have formed our development cultures from the flints of the Stone Age man to the uranium ores of Atomic Age”. The ambition with this handbook, “Basics in Minerals Processing”, is not to give a full coverage of the subject above. The intention is to give technicians involved in mineral operations practical and useful information about the process equipment used, their systems and operational environment. The technical data given are basic, but will increase the understanding of the individual machines, their functions and performances. Always contact Metso Outotec for information regarding specific products since the data given is subject to change without notice. 1.1 Basic definitions It is important to know the definitions of mineral, rock and ore as they represent different product values and partly different process systems Mineral Rock Ore Na+ Ca + Si4+ O2- Mineral Mineral 2 Mineral Rock Rock CO22- Fe2+ OH- Heat Pressure Heat Pressure Heat Pressure Deformation Chemical activity Ca Co3 Fe2 O3 Rock Rock SiO2 Ore Ore Ore Artificial minerals “Man made” minerals are not minerals by definitions. But from processing point of view they are similar to virgin minerals and are treated accordingly (mainly in recycling processes). Slag Concrete Mill scale Glass & Ceramics 13 14 1.2 Minerals Industrial minerals Mineral fuels Rock Ores Minerals by value Abrasives Ceramics Refractories Non-ferrous Ferrous alloy Ferrous Corundum Quartz Wollastonite Coals Oil shale Base metals Alloying metals Iron Quartz Kaolin Calcite (Oil sand) Copper Chromium Diamond a.o. Feldspar a.o. Dolomite Lead Vanadium Glass Fertilisers Corundum a.o. Zinc a.o. Molybdenum Quartz Phosphate Tungsten Feldspar Potash Aggregate, sand & gravel Light metals a.o. Calcite Calcite Aluminium Dolomite a.o. Dolomite a.o. Concrete ballast Magnesium Plastic Fillers and pigment Asphalt ballast Titanium Calcite Barite Rock fill Kaolin Bentonite Industrial sand Precious metals Talc Calcite a.o. Gold Wollastonite Dolomite Silver Mica a.o. Feldspar Platinum a.o. Talc a.o. Rare metals Uranium Radium Beryllium a.o. 1.3 The process frame of minerals The goal in mineral processing is to produce maximum value from a given raw material. This goal can be a crushed product with certain size and shape or maximum recovery of metals out of a complex ore. The technologies to achieve these goals are classical, complementary and well defined. Below they are presented in the Process Frame of Minerals, classified according to their interrelations in product size and process environment (dry or wet). Size 1m 100 mm 10 mm 1 mm 100 micron 10 micron 1 micron Drilling (and blasting) is the technology of achieving primary fragmentation of “in situ” minerals. This is the starting point for most mineral processes with the exception of natural minerals in the form of sand and gravel. Crushing and screening is the first controlled size reduction stage in the p ­ rocess. This is the main process in aggregate production and a preparation process for further size reduction. Grinding is the stage of size reduction (wet or dry) where the liberation size for individual minerals can be reached. By further size reduction filler (mineral powder) is produced. Slurry processing includes the technologies for wet processing of mineral fractions. Pyro processing includes the technologies for upgrading of the mineral fractions by drying, calcining or sintering. Materials handling includes the technologies for moving the process flow (dry) forward by loading, transportation, storage and feeding. Compaction of minerals includes the technologies for moving and densifying minerals by vibration, impaction and pressure, mainly used in construction a­ pplications. 15  1.4 Mineral processing and hardness All deposits of minerals, rock or ores have different hardness depending on the chemical composition and the geological environment. Mohs numbers are a simple classification: 1. Talc Crushed by a finger nail Graphite, Sulphur, Mica, Gold 2. Gypsum Scratched by a finger nail Dolomite 3. Calcite Scratched by an iron nail Magnesite 4. Fluorite Easily scratched by a knife Magnetite 5. Apatite Scratched by a knife Granite, Pyrite 6. Feldspar Hardly scratched by a knife Basalt 7. Quartz Scratches glass Beryl 8. Topaz Scratched by quartz 9. Corundum Scratched by a diamond 10. Diamond Cannot be scratched In 1813 an Austrian geologist, Mr. Mohs, classified minerals according to their individual hardness. In operation we naturally need more information about our feed material. See information on work index and abrasion index, section 3 page 2. 1.5 Size and hardness All operations have different process environments due to mineral hardness and size range. It is important to know in which “range” we are operating as this will affect many process parameters, (wear rate, uptime, operation costs etc.). Size and hardness together give interesting information. Hardness Mohs 10 METALLIC 9 ROCK CONSTRUCTION MATERIALS MINERALS 8 BALLAST 7 6 AGGREGATES SAND 5 4 MICRO FILLER SAND 3 2 INDUSTRIAL 1 MINERALS COARSE FILLER FINE FILLER Size 1m 100 mm 10 mm 1 mm 100 micron 10 micron 1 micron 8 16 1.6 The stress forces of rock mechanics Beside size and hardness, the classical stress forces of rock mechanics are the fundamentals in most of what we do in mineral processing. They guide us in equipment design, in systems layout, in wear protection etc. They are always around and they always have to be considered. Tensile Compression Impaction Shearing Attrition 17  Minerals in operation 18 2. Minerals in operation 2.1 Operation stages The operating stages in minerals processing have remained the same for t­housands of years. Of course we have come far in development of equipment and processes since then, but the hard, abrasive and inhomogeneous mineral crystals have to be treated in special ways in order to extract maximum value out of each size fraction. The operation pattern below has been used since the days of “ mineralis antiqua” PROTECTION SIZE REDUCTION FRONT ENRICHMENT UPGRADING AND SERVICE CONTROL MATERIALS HANDLING Front service: Starting point of mineral processing Size reduction & control: Processes to produce requested size distributions from feed material Enrichment: Processes to improve value of minerals by washing and/or separation Upgrading: Processes to produce requested end products from value and waste minerals. Materials handling: Operations for moving the processes forward with a minimum of flow disturbances Protection: Measures to protect the process environment above from wear and emissions of dust and sound 2.2 Operation – Dry or wet ? Dry processing Wet processing When no water is needed for processing In all other cases due to: When no water is allowed for processing Better efficiency More compact installation No dusting Note! Wear rate is generally higher in wet processing! 19  2.3 Mining and quarry fronts The mining and quarry fronts are the starting points for recovery of rock and mineral values from surface and underground deposits. Operations are drilling (blasting), primary crushing (optional) and materials handling, dry and wet. Mining and quarrying Underground Open pit 2.4 Natural fronts In the glacial, alluvial and marine fronts nature has done most of the primary size reduction work. Raw material such as gravel, sand and clay are important for processing of construction ballast, metals and industrial mineral fillers. Operations are materials handling (wet and dry) and front crushing (optional). Glacial Glacial sand and gravel occur in areas which are – or have been – covered by ice. The material is rounded and completely unsorted with an heterogeneous size distribution which ranges from boulders larger than 1 m (3 ft) down to silt (2-20 microns). Clay contamination is concentrated in well defined layers. 20 Alluvial The size of alluvial sand and gravel depends on the flow velocity of the water, among other things. Normally the maximum size is around 100 mm (4”). Alluvial sand and gravel have a homogeneous size distribution and larger particles often have high silica content. The clay content is often high, normally in the range of 5 to 15 %. Alluvial fronts are in certain areas hosting gold, tin and precious stones. Marine Marine sand and gravel often have a more limited size distribution than other types of sand and gravel. The minerals in marine sand and gravel have survived thousands – or even millions of years – of natural attrition, from erosion in the mountain ranges and grinding during transport down to the sea. The particles have become well rounded and the clay content is extremely low. Marine fronts are in certain areas hosting heavy minerals like hematite, magnetite, rutile a.o. 21  2.5 Size reduction Crushing of rock and minerals By tonnage this is by far the largest process operation in minerals processing. The goal is to produce rock or (more seldom) mineral fractions to be used as rock fill or ballast material for concrete and asphalt production. Quality parameters are normally strength, size and shape. The size fractions, see below, are priced according to defined size intervals and can be reached by crushing only, see section 3. HSI IMPACTORS PRIMARY PRIMARY AND GYRATORY SECONDARY CRUSHER CRUSHER CONE CRUSHER SECONDARY Product value CONE CRUSHER CRUSHERS TERTIARY VSI JAW CRUSHER >1000 >500 >100>80 64 32 22 16 11 8 4 0 Size mm Crushing and grinding of ore and minerals Size reduction of ores is normally done in order to liberate the value minerals from the host rock. This means that we must reach the liberation size, normally in the interval 100 – 10 micron, see value curve 1 above. If the raw material is a single mineral (Calcite, Feldspar a.o.) the value normally lays in the production of very fine powder (filler), see value curve 2 below. In order to maximise the value in size reduction of rock and minerals, see below, we need both crushing and grinding in various combinations, see section 3. The equipment shown below is a general application range. The actual range depends on the material properties and process requirements. PRIMARY GYRATORY HRC CRUSHER VERTIMILL CONE CRUSHER AG/SAG 1. MILLS 2. CRUSHERS/ IMPACTORS STIRRED ROD MEDIA DETRITOR BALL JAW PEBBLE VSI CRUSHER 100 micron Size 1m 100 mm 10 mm 1 mm 100 micron 10 micron 1 micron 8 22 2.6 Size control Neither crushers nor grinding mills are very precise when it comes to the correct sizing of the end products. The reason is to find partly in the variation of the mineral crystals compounds (hard-soft, abrasive – non abrasive), partly in the design and performance of the equipment. Size control is the tool for improvement of the size fractions in the process stages and in the final products. For the coarser part of the process, screens are used (in practise above 1-2 mm). In the finer part we have to use classification with spiral classifiers, see section 4. 100 micron Size 1m 10 mm 10 mm 1 mm 100 micron 10 micron 1 micron 8 2.7 Enrichment – Washing Washing is the simplest method of enrichment used to improve the value of rock and mineral fractions from sand size and upwards. Removing of surface impurities like clay, dust, organics or salts is often a must for a saleable product. Different techniques are used depending on how hard these impurities are a­ ttached to the rock or mineral surface, see section 5. Washing using Wet screens* Scrubbers* Attrition cells* Gravity beds* * Contact Metso Outotec for further information. 23  2.8 Enrichment – Separation Most value minerals (both metallic and industrial) are priced by their purity. After liberation by size reduction and size control all minerals are free to be separated from each other. Depending on the properties of the individual minerals they can be recovered by different methods of separation, see section 5. Gravimetric Flotation Magnetic Leaching      Gravity Air = value mineral 2.9 Upgrading After the enrichment operation we end up with a value product (concentrate) and a non-value product (tailings). These products are probably not sellable nor disposable due to the content of process water, particle size, or chemical composition. By upgrading we mean the methods of increasing the value of these products by sedimentation, mechanical dewatering, drying, calcining or sintering and recovering the process water from the tailings, making them disposable, see section 6. Upgrading by methods RELATIVE COST SINTERING CALCINING DRYING DEWATERING BY TUBE PRESSES DEWATERING BY PRESSURE FILTERS DEWATERING BY VACUUM FILTERS DEWATERING BY SCREENS DEWATERING BY SPIRALS SEDIMENTATION Size 100 mm 10 mm 1 mm 100 micron 10 micron 1 micron 24 2.10 Materials handling Without a proper set up for materials handling no processing system will perform. Different process stages may be in various locations, may have various feed conditions, are on different shift cycles etc. Materials handling of dry material is based on the operations of loadíng, unloading, transportation, storing and feeding, see section 7. Materials handling of wet material, called slurry handling is also based on the operations of transportation (by slurry pumps and hoses), feeding (by slurry pumps) and storage (by slurry agitation), see section 8. Dry handling Slurry handling            25  2.11 Wear in operation Whenever energy in any form penetrates rock, ore or mineral, wear will appear. There is of course a difference whether the minerals are hard or soft, small or large, abrasive or non-abrasive, wet or dry, but wear will always be around. Both machines and structures must be protected from wear using metals, polymers or compound material. See section 9, wear in operation. 26 2.12 Operation and environment If wear is dangerous for equipment and structures, dust and noise is primarily a danger to the operators. Dust is a problem to both equipment and operators in dry processing Noise is a problem to operators both in wet and dry processing. By tradition, the environment in mineral processing has a bad reputation. This is now changing fast due to harder restrictions by law and harder demands from the operators, see section 10, Operation and environment. 2.13 Operation values Prices for products from your operation are seldom set by yourself, but by the market buying them. There is always a possibility to increase the income from your operation by added values generated by the operation itself. By improving the output we can increase the product volumes By improving the quality we can increase the price of our products By improving the cost control we can reduce our costs of operation By improving the comfort for our operators we can improve motivation and reduce disturbances in operation This can be done by small adjustments, by improved service or by reinvestment in more effective equipment, see all sections. Added value in operation VOLUME x PRICE – COSTS + MOTIVATION = S Output Quality Cost control Comfort AVAILABILITY SIZE / CAPITAL SECURITY (up time) SHAPE PURITY / ENVIRON- CAPACITY ENERGY RECOVERY MENT COMPAC- FLEXIBILITY TION / MATERIAL RELATIONS DENSITY 27  Size reduction 28 3. Size reduction 3.1 The size reduction process Minerals being crystals have a tendency to break into endless numbers of sizes and shapes every time they are introduced to energy. The difficulty in size reduction lays in the art of limiting the number of over and under sizes produced during the reduction. If this is not controlled, the mineral will follow its natural crystal behaviour, normally ending up in over-representation of fines. I II III IV V Reduction stage 80% passing Size 1m 100 mm 10 mm 1 mm 100 micron 10 micron 1 micron 8 Size reduction behaviour of minerals - by nature Note! There is a large benefit to flotation and separation if there is a steep size distribution of the feed to these processes. So, the trick when producing quality products from rock or minerals (fillers excepted) is to keep the size reduction curves in the later stages as steep as possible. Normally that is what we get paid for – the shorter or more narrow fraction – the more value! To achieve that goal we need to select the correct equipment out of the repertoire for size reduction in a proper way. They are all different when it comes to reduction technique, reduction ratio, feed size etc. and have to be combined in the optimum way to reach or come close to the requested size interval for the end product. 29  3.2 Feed material All operations in size reduction, both crushing and grinding are of course determined by the feed characteristics of the minerals (rock/ore) moving into the circuit. The key parameters we need are the “crushability or grindability”, also called work index and the “wear profile”, called abrasion index. Values for some typical feed materials from crushing of rocks, minerals and ore are tabulated below. Impact Work Index Wi kWh/sh.ton Abrasion index = Ai Material Wi value Material Ai value Basalt 20 ± 4 Basalt 0,200 ± 0,20 Diabase 19 ± 4 Diabase 0,300 ± 0,10 Dolomite 12 ± 3 Dolomite 0,010 ± 0,05 Iron-ore, Hematite 13 ± 8 Iron-ore, Hematite 0,500 ± 0,30 Iron-ore, Magnetite 12 ± 8 Iron-ore, Magnetite 0,200 ± 0,10 Gabbro 20 ± 3 Gabbro 0,400 ± 0,10 Gneiss 16 ± 4 Gneiss 0,500 ± 0,10 Granite 16 ± 6 Granite 0,550 ± 0,10 Greywacke 18 ± 3 Greywacke 0,300 ± 0,10 Limestone 12 ± 3 Limestone 0,001 – 0,03 Quartzite 16 ± 3 Quartzite 0,750 ± 0,10 Porphyry 18 ± 3 Porphyry 0,100 – 0,90 Sandstone 10 ± 3 Sandstone 0,600 ± 0,20 Syenite 19 ± 4 Syenite 0,400 ± 0,10 INFLUENCING INFLUENCING Size reduction Wear rate Energy requirement Regarding Work Index (Bond) for grinding, see 3:40. Machine status 3.3 Reduction ratio As seen above all size reduction operations are performed in stages. All equipment involved, crushers or grinding mills have different relation between feed and discharge sizes. This is called reduction ratio. Typical values below. Note! High reduction ratio is generally inefficient. For maximum energy efficiency, we recommend multiple stages of grinding Compression crushers Impactors (horizontal type) Impactors (vertical type) Jaw 3-4 Gyratory 3-5 5-10 1-2 Cone 3-5 High pressure grinding rolls Grinding mills (tumbling type) Stirred grinding mills Rod 100 Ball 1000 AG & SAG 5000 25 100 30 3.4 The art of crushing Crushing means different things for different operations and the production goals are not always equal. Crushing rock Crushing gravel Crushing ore Limited reduction Limited reduction Maximum reduction Cubical shape Cubical shape Shape of no importance Over and undersize Over and undersize Over and under size important important of minor importance Flexibility of minor Flexibility Flexibility importance Crushing and Less crushing - More crushing- screening more screening less screening Low production costs High utilisation 3.5 Crushing of rock and gravel In the business you are normally paid for short fractions of relatively coarse material with the correct size and shape. Most of the ballast for concrete and asphalt is in the 4 - 18 mm (1/5 - 3/4’’) interval. In order to produce the correct shape and keep over- and under sizes as low as possible this crushing must be done in several stages (3 - 5). 31  3.6 Crushing of ore and minerals In these operations the value is achieved at the fine end, say below 100 micron (150 mesh). Normally the size reduction by crushing is of limited importance besides the top size of the product going to grinding. This means that the number of crushing stages can be reduced depending on the feed size accepted by primary grinding stage. ”Classical” 3-stage crushing prior to rod mill Primary crushing Tertiary crushing Secondary crushing Typical 1-2 stage ore crushing in AG-SAG circuit Primary crushing Secondary crushing Primary grinding Typical 3- stage crushing prior to ball mill 3-stage crushing utilizing an HPGR prior to a rod mill or ball mill Another option is including HPGRs in the crushing circuit. Commons circuits include utilizing HPGRs as a: Primary – tertiary crusher, followed by a ball mill or VERTIMILL® crushing – quarternary crusher, followed by a ball mill or VERTIMILL® – pebble crusher in a SABC circuit Secondary Primary Tertiary crushing crushing HPGR crusher crushing Secondary crushing 32 3.7 Crushing – Calculation of reduction ratio All crushers have a limited reduction ratio meaning that size reduction will take place in stages. The number of stages is guided by the size of the feed and the requested product, example see below. The same size reduction with soft feed (low Bond work index) is done with two stages of  Feed material size: F80 = 400 mm  Blasted rock, 80% smaller than 400 mm    Product size: P80 = 16 mm   Road aggregates or rod mill feed 80% smaller than 16 mm      Total reduction ratio (R) F80/P80 400/16 = 25   Reduction ratio in the primary crushing stage R1 = 3  Reduction ratio in the secondary crushing stage R2 = 4   Total in 2 crushing stages gives R1xR2 = 3x4 = 12  This is not sufficient. We need a third crushing stage.* *As we have to use three stages, we can reduce the reduction ratio a bit in every stage, giving more flexibility to the circuit! For example: Reduction first stage R1 = 3 Reduction second stage R2 = 3 Reduction third stage R3 = 3 Together these three stages give R1xR2xR3 = 3x3x3 = 27 = sufficient reduction Stage I JAW CRUSHER I Stage II CONE CRUSHER II Reduction ratio 1:3 Stage III CONE CRUSHER III Reduction ratio 1:3 Reduction ratio 1:3 100 micron >1000 >500 >100 >80 64 32 22 16 11 8 4 0 Size mm The same size reduction with soft feed (low Bond work index) is done with two stages of HSI (horizontal shaft impactors). With the increased reduction ratio capable in an impactor this process can be achieved in two stages, such as 6:1 and 5:1. 33  3.8 Selection of crushers Knowing the number of crushing stages we can now start to select the correct crusher for each reduction stage. Depending on operating conditions, feed size, capacity, hardness etc, there are always some options. For primary crushers, see below. Stationary crushers – surface and underground Primary Gyratory Jaw Impact Mobile Crushers Jaw + grizzly Impact + grizzly For mobile crushers see further section 11:9 3.9 Primary crusher – Type For soft feed and non-abarasive feed (low Bond work index) a horizontal Impactor (HSI) is an option if the capacity is not too high. For harder feed there is a choice between a gyratory or a jaw crusher, see below. Note: HSI can be used only if the abrasion index is lower and the plant does not mind fines production. Otherwise, a jaw crusher is preferred for lower capacity aggregate plants.) Rule 1: Always use a jaw crusher if you can, jaws are the least capital cost. Rule 2: For low capacity use jaw crusher and hydraulic Feed opening Feed opening hammer for oversize. Jaw crusher Gyratory crusher Rule 3: For high capacities (800-1500 tph)use jaw crusher with big intake opening. Rule 4: For very high capacities (1200+ tph use gyratory crusher. Discharge opening Discharge opening Jaw crusher Gyratory crusher 34 3.10 Primary crusher – Sizing Crushers are normally sized from top size of feed. At a certain feed size, knowing the capacity, we can select the correct machine, see below. A correct sizing of any crusher is not easy and the charts below can only be used for guidance. Ex. Feed is a blasted hard rock ore with top size 750 mm. Capacity is 4750 t/h. Which primary crusher can do the job? Check on the two compression machines below and take out the sizing point! Correct selection is Superior® MK-II Primary Gyratory Crusher type MK-II 60-89 Primary gyratory – Feed size vs capacity Feed top size mm (inch: divide by 25) 1500 MK-II 62 - 75 MK-II 60 - 89 Data sheet, MK-II 60 - 110 E MK-II 50 - 65 see 3:15 1000 MK-II MK-II 42 - 65 54 - 75 500 Capacity t/h 2000 3000 4000 5000 6000 7000 8000 9000 Primary jaw crusher – Feed size vs capacity 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 0,1 1 10 100 1000 Primary impactor – Feed size vs capacity Feed top size mm (inch: divide by 25) 1500 NP2023 1300 NP1620 1000 900 NP1415 Data sheet, NP1313 see 3:17 700 600 400 350 0 Capacity t/h 0 500 1000 1500 2000 35  3.11 Secondary crusher – Type In a rock crushing circuit, the second stage normally starts to be of importance for control of size and shape. Because of this the jaw crusher, in most cases, is disqualified as secondary crusher. Instead the cone crusher is used more frequently. Also in comminution (crushing and grinding) circuits for ore and minerals the cone crusher is frequently used as the secondary stage, see 3:4. Using a secondary HSI means as always a restriction in feed hardness and abrasiveness. Yesterday Today Demands Limitations in Wi and Ai Big feed opening High capacity Controlled feed Shape HSI Jaw Crusher Cone Crusher 3.12 Cone crusher – A powerful concept Compared to other crushers the cone crusher has some advantages making them very suitable for size reduction and shaping downstream a crushing circuit. Reason is the crushing chamber and the possibilities to change feed and discharge openings during operation. Chamber geometry Closed side setting Chamber settings (CSS) Upper concave + Eccentric setting (Ecc.) = Open side setting (OSS) CSS OSS Nip an Ecc. gle Concave Lower concave CSS, Closed Mantle Mantle Side CSS, Setting Closed Side Setting Chamber intake to match feed size Decreased CSS will improve reduction but will also reduce Each machine size has different chamber options (other capacity and increase risk for packing crusher types have not) Approx. size of discharge: Each chamber has a certain feed size vs capacity relation Increased Ecc. (at the same CSS) will give higher capacity. From Cone 70-80%120 48 – 120 7 – 48 4–7 50 20 – 50 3 – 20 1.5 – 3 60 weight Specific gravity dry solids 75% Rakes are lifted until 100% load is reached. Rakes stay in upper position until 70% is reached, then lowering towards bottom position. > 100% Cut-out torque stops rotation of rakes. Lifting to the top position and alarm. Starts up normally from drive head control panel. Control panel PLC controlled Fully automatic incl. functions for: – Speed control of flocculator – Torque signal – Start and stop sequences – Alarm indications for levels, flows etc. – Control of underflow valve and pump 164 6.16 Inclined Plate Settler – Product range Type LTO Sizes up to 400 m2 (4 305 ft2) ­effective clarification area (500 m² total projected area) Effective also with coarser material Limited solids content in feed Extension of lower part as option Lifting device as option See also data sheet 6:16. Type LTS Sizes up to 400 m2 (4 305 ft2) e ­ ffective clarification area (500 m² total projected area) Not suitable for coarse material (> 0.5-1 mm, 32 – 16 Mesh) Higher solids load Extension of lower part as option Lifting device as option See also data sheet 6:17. Type LTK Sizes up to 400 m2 (4 305 ft2) e­ ffective clarification area (500 m² total projected area) For higher solids load Used when storage and thickening is critical Extension of lower part as option Lifting device as standard See also data sheet 6:18. 165  Type LTO, LTS, LTK with extended tank By lower tank extensions the volume can be increased giving better storage and improved thickening. Type combi LTC Sizes up to tank dia 24 m (78.7 ft) = 400 m2 (53 800 ft2) For light and heavy duties High storage capacity Improved thickening Plate or concrete tank Conventional thickener drives See also data sheet 6:21. “Combi IPS” built up by using inclined plate packs in circular tanks have principally no limitation in sizes. From design point, however, max. practical area for each plate pack unit is approx. 5 400 m2. These sizes can then be combined in modules 5 400 m2 + 5 400 m2 +... (58 125 ft 2+ 58 1250 ft 2 +...) 166 Type LTE Sizes up to 1 140 m2 (12 270 ft2) projected area. Increased solids storage capacity, e.g. for installation prior to a batch process such as a filter press. See also data sheet 6:19. Type LTE/C Similar to LTE above. Conical bottom for denser underflow. Improved access to underflow valves, pump and piping. See also data sheet 6:20.     167  Technical data sheet 6.17 Inclined Plate Settler – LTO H Total Sludge Flocculator Weight L W A Model (max) volume volume volume empty mm (ft) mm (ft) mm (ft) mm (ft) mm³ (ft³) m³ (ft³) m³ (ft³) kg (lbs) 3 485 2 640 1 345 1 800 4.6 1.1 0.8 1 800 LTO 15 (11.4) (8.7) (4.4) (5.9) (162) (39) (28) (3 968) 4 300 3 430 1 830 1 800 9.2 2.3 0.8 3 500 LTO 30 (14.1) (11.3) (6.0) (5.9) (325) (81) (28) (7 716) 4 650 3 865 2 230 1 800 16.2 4.2 2.0 4 800 LTO 50 (15.3) (12.7) (7.3) (5.9) (572) (148) (71) (10 582) 5 400 4 510 2 870 1 800 28.7 9.4 3.0 7 800 LTO 100 (17.7) (14.8) (9.4) (5.9) (1 014) (332) (106) (17 196) 5 950 5 540 3 100 1 800 41.5 14.5 4.0 10 500 LTO 150 (19.5) (18.2) (10.2) (5.9) (1 466) (512) (141) (23 149) 6 500 5 740 3 690 1 800 54.6 18.8 5.0 13 200 LTO 200 (21.3) (18.8) (12.1) (5.9) (1 928) (664) (177) (29 101) 8 100 6 910 4 500 2 000 105.8 47.8 7.0 24 300 LTO 350 (26.6) (22.7) (14.8) (6.6) (3 736) (1 688) (247) (53 572) 8 630 7 810 5 780 2 000 160.8 72.8 8.0 39 500 LTO 500 (28.3) (25.6) (19.0) (6.6) (5 679) (2 571) (283) (87 082) 168 Technical data sheet 6.18 Inclined Plate Settler – LTS H Total Sludge Flocculator Weight L W A Model (max) volume volume volume empty mm (ft) mm (ft) mm (ft) mm (ft) mm³ (ft³) m³ (ft³) m³ (ft³) kg (lbs) 3 750 2 640 1 345 1 800 5.2 1.7 0.8 2 000 LTS 15 (12.3) (8.7) (4.4) (5.91) (184) (60) (28) (4 409) 4 620 3 430 1 830 1 800 11.1 4.2 0.8 3 700 LTS 30 (15.2) (11.3) (6.0) (5.91) (392) (148) (28) (8 157) 4 700 3 865 2 230 1 800 18.6 6.6 2.0 5 100 LTS 50 (15.4) (12.7) (7.3) (5.91) (657) (233) (71) (11 244) 5 130 4 510 2 870 1 800 32.5 13.2 3.0 8 600 LTS 100 (16.8) (14.8) (9.4) (5.91) (1 148) (466) (106) (18 960) 5 300 5 540 3 100 1 800 45.8 18.8 4.0 11 300 LTS 150 (17.4) (18.2) (10.2) (5.91) (1 617) (664) (141) (24 912) 6 100 5 740 3 690 1 800 61.8 26.0 5.0 15 800 LTS 200 (20.01) (18.8) (12.1) (5.91) (2 182) (918) (177) (34 833) 6 200 6 910 4 500 2 000 114.0 56.0 7.0 23 000 LTS 350 (20.3) (22.7) (14.8) (6.56) (4 026) (1 978) (247) (50 706) 6 400 7 810 5 780 2 000 153.0 65.0 8.0 36 000 LTS 500 (21.0) (25.6) (19.0) (6.56) (5 403) (2 295) (283) (79 366) 169  Technical data sheet 6.19 Inclined Plate Settler – LTK Total Sludge Flocculator Weight H L W A Model volume volume volume empty mm (ft) mm (ft) mm (ft) mm (ft) mm³ (ft³) m³ (ft³) m³ (ft³) kg (lbs) 5 100 2 795 1 610 1 800 8.0 4.5 0.8 2 200 LTK 15 (16.7) (9.2) (5.3) (5.9) (283) (159) (28) (4 850) 4 550 3 690 2 310 1 800 14.5 7.6 0.8 4 500 LTK 30 (14.9) (12.11) (7.6) (5.9) (512) (268) (28) (9 921) 4 800 4 170 2 810 1 800 23.5 11.5 2.0 6 200 LTK 50 (15.7) (13.7) (9.2) (5.9) (830) (406) (71) (13 669) 5 390 5 020 3 715 1 800 45.5 26.2 3.0 10 100 LTK 100 (17.7) (16.5) (12.2) (5.9) (1 607) (925) (106) (22 267) 5 800 5 885 4 490 1 800 61.0 34.0 4.0 13 000 LTK 150 (19.0) (19.3) (14.7) (5.9) (2 154) (1 201) (141) (28 660) 6 500 6 235 4 715 1 800 87.0 51.2 5.0 16 500 LTK 200 (21.3) (20.6) (15.5) (5.9) (3 072) (1 808) (177) (36 376) 6 930 7 485 6 220 2 000 143.0 85.0 7.0 26 500 LTK 350 (22.7) (24.6) (20.4) (6.6) (5 050) (3 002) (247) (58 422) 6 940 8 705 7 520 2 000 200.0 112.0 8.0 46 500 LTK 500 (22,8) (28,6) (24,7) (6,6) (7 063) (3 955) (283) (102 515) 170 Technical data sheet 6.20 Inclined Plate Settler – LTE D 1,5 - 2,5 m 4.5 - 7.5 ft H Settling area Tank dia (D) Tank height (H) Sludge volume Total volume Model m2 (ft2) mm (ft) mm (ft) m3 (ft3) m3 (ft3) LTE 220-6.3 220 (2 386) 6 300 (20.7) 6 000 (19.7) 86 (3 040) 192 (6 780) 9 000 (29.5) 179 (6 320) 285 (10 065) LTE 275-7.1 275 (2 960) 7 100 (23.3) 6 000 (19.7) 110 (3 885) 244 (8 629) 9 000 (29.5) 228 (8 050) 363 (12 820) LTE 440-8.3 440 (4736) 8 300 (27.0) 6 000 (19.7) 151 (5 335) 335 (11 830) 9 000 (29.5) 314 (11 090) 497 (17 550) 12 000 (39.4) 476 (16 810) 660 (23 310) LTE 550-9.0 550 (5 920) 9 000 (29.5) 6 000 (19.7) 179 (6 320) 395 (13 950) 9 000 (29.5) 370 (13 065) 586 (20 695) 12 000 (39.4) 561 (19 810) 777 (27 440) LTE800-10.5 800 (8 611) 10 500 (34.4) 6 000 (19.7) 246 (8 690) 541 (19 105) 9 000 (29.5) 506 (17 870) 801 (28 290) 12 000 (39.4) 766 (27 050) 1 060 (37 435) LTE 1140 1 140 (12 270) 12 000 (39.4) 6 000 (19.7) 326 (11 510) 710 (25 0705) 9 000 (29.5) 665 (23 480) 1 050 (37 080) 12 000 (39.4) 1004 (35 4555) 1 389 (49 050) 171  Technical data sheet 6.21 Inclined Plate Settler – LTE/C  1,5 - 2,5 m 4.9 -8.2 ft  (3.3 ft)  Settling area Tank dia (D) Tank height (H) Sludge volume Total volume Model m2 (ft2) mm (ft) mm (ft) m3 (ft3) m3 (ft3) LTE/C 220-6.3 220 (2 368) 6 300 (20.7) 8 500 (27.9) 66 (2 3301) 172 (6 075) LTE/C 275-7.1 275 (2 960) 7 100 (23.3) 10 000 (33.0) 91 (3 215) 225 (7 945) LTE/C 440-8.3 440 (4 736) 8 300 (27.2) 11 000 (36.0) 140 (4 945) 324 (11 440) LTE/C 550-9.0 550 (5 920) 9 000 (29.5) 11 500 (37.7) 175 (6 180) 391 (13 810) LTE/C 800-10.5 800 (8 611) 10 500 (34.4) 12 500 (41.0) 269 (9 500) 563 (19 880) LTE/C 1040-12 1 140 (11 194) 12 000 (39.4) 13 500 (44.3) 392 (13 845) 776 (27 405) 172 Technical data sheet 6.22 Inclined Plate Settler – LTC D 1,5 - 2,5 m 4.9 - 9.2 ft H *Model Settling Tank Tank height **Sludge Total area dia