CrossFlow Separators: Maple Creek Coal Preparation Plant An Overview
OUTLINE CrossFlow Separator Introduction Testing CrossFlow: Coal Advantages
What is the CrossFlow? Conventional Cross-Flow Feed Feed Increased Velocity Constant Velocity Fines Constant Velocity Fines Water Water Coarse Coarse
What is the CrossFlow? Feed Overflow Separation Chamber Feed Well Fluidization Water Dewatering Cone Control Loop PID Underflow
What is the CrossFlow? The Eriez CrossFlow is a hydraulic teeter-bed separator used to upgrade minerals/coal based on size and SG (particles ranging from 0.2-4 mm). The device operates based on the principle of hindered settling of solids against a rising water flow.
CrossFlow Separator Used as a classification device. Exploits the different settling velocities between particles of varying size. Used as a gravity separation device provided size range is tight enough. Exploits the density difference between particle types. Coal (1.2 from 2.7) Low Density Particles Iron Ore (5.1 from 2.65) High Density Particles Heavy Minerals (5.0+ Water from 2.8)
Hindered-Bed Separators: CrossFlow Separator Injection of Fluidization Water across the Base of the Separator. Suspends the Particles into a Teeter-Bed. Use Water Rate to Control Separation Cut-Point Low Density Particles High Density Particles Water
OUTLINE CrossFlow Separator Introduction Testing CrossFlow: Coal Advantages
CrossFlow Testing: Sizing Partition Factor (% 100 90 80 70 60 50 40 30 20 Unbalanced Balanced 10 0 0.1 1.0 Mean Size (mm) High Classification Efficiency
Comparative Testing: Sizing Imperfection 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Conventional CrossFlow 0 2 4 6 8 10 Feed Rate (tph/ft 2 )
Comparative Testing: Sizing 0.16 0.14 0.12 0.10 Ep 0.08 0.06 0.04 0.02 0.00 CrossFlow Conventional 0.20 0.30 0.40 0.50 0.60 Separation Cut-Point (mm)
Comparative Testing: Gravity 100 HM Recovery (%) 80 60 40 20 CrossFlow Conventional 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Feed Rate (tph/ft 2 )
OUTLINE CrossFlow Separator Introduction Testing CrossFlow: Coal Advantages
Maple Creek Preparation Plant Maple Creek Preparation Plant is located in Pennsylvania USA. Crossflow Separator to replace Coal Spirals 7 x 7 Crossflow Separator Installed Operating at 100 t/h (Designed for 200 t/h)
Maple Creek CrossFlow (Coal) PID Loop Controller
PLANT FEED CrossFlow Separator (Coal) Typical Circuit COARSE -200 microns Classifying Cyclones Flotation -1.0 mm Feed Sump Deslime Sieves +200 microns CLEAN COAL FINE REJECT
CrossFlow Separator (Coal) 100 CrossFlow Test Results (As-Received) Recovery (%) 90 80 70 60 Combustible (Coal) - Pilot-Testing Combustible (Coal) - Full-Scale Mass (Yield) - Pilot-Testing Mass (Yield) - Full-Scale 0 5 10 15 20 Product Ash (%)
OUTLINE CrossFlow Separator Introduction Testing CrossFlow: Coal Advantages
CrossFlow Advantages vs. Spirals 12 Triple Stacks = 36 Separators All Must Operate at Same SG 50 Circulating Loads (Midds) Excessive Head Room Only 2-3 tph/start High Maintenance (cleaning) Manual Control (adjust splitters) One Separator/Small Footprint High Efficiency/One Cut-Point Low Operating Costs No Extraneous Piping High Capacity (4 tph/sqft) Low Maintenance Automatic Control
CrossFlow Advantages vs. Other Sizers Low Through-put (2-3 tph/sqft) Cannot handle swings in feed percent solids Possible plugging of orifice plates Poor control of water splits Low percent solids discharge leading to high valve wear High Through-put (up to 2x conventional separators High Classification Efficiency Can handle large swings in volumetric feed flow rate No plugging, Low Maintenance Excellent control of water splits