Cubicity
Uploaded by
zsmithCubicity
Uploaded by
zsmithCubicity
Sandvik Rock Processing
Quarry Academy 2005
Design of a Plant circuit
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T ? How do we get a
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cubical product from a
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Hydrocone crusher or
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y a Merlin VSI?
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Quarry Academy 2005
Good shape fractions
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z Rail-way Ballast 32-56(63) mm from secondary crusher
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e z Concrete fractions 8-16, 16-32 mm and sand
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s z Asphalt fractions 4(5)-8, 8-11, 11-16 and 16-22 mm.
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e z Most critical fraction to get cubical are the 4-8 or 5-8 mm
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and crushed concrete sand
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Quarry Academy 2005
Test norms
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Test methods for determining cubical shape
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z Europe
e 9 Shape index (SI) where L/T > 3
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s 9 Flakiness Index (FI) W/T where W/T > 0.6
T z British Standard BS 812, Flake Index, the slot hole
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c width is 3/5 of the median dimension of the fraction.
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n z ASTM – Superpave L/T > 5
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l z Others, Russia, China, India etc
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Quarry Academy 2005
Feed materials
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Rule of thumbs
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z Higher Impact Work Index (WI) gives in H/C larger CSS
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z Materials with coarse crystalline structure usually give
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better shape than fine crystalline material.
e 9Coarse crystalline is for example Granite, Gneiss.
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h 9Fine crystalline is for example Basalt, Diabase
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o z Sedimantary rocks can be difficult to shape up due to the
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o laminar structure in the material
g 9 Laminar structure in for example Slate, Sandstone
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z Long feed fractions normally gives better shape
e 9Top feed size < 3/4 of intake opening
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t 9In Merlin VSI 0-fraction increase the cubicity
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r z Contaminations reduce the possibility of produce good
shape
Quarry Academy 2005
Important guidelines H/C
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To get cubical products from the Hydrocone
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z The crusher should always be choke fed
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z Surge Bin with feeder and the Surge Bin equipped with
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max/min level indicators.(min level indicator interlocked
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with the feeder).
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z Max level indicator in the feed Hopper of the Hydrocone
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to be interlocked with the feeder.
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z Long fraction (4-32 mm) gives high pressure in the
y crushing chamber and more interparticle crushing
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z Max feed size ¾ of intake
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z Preferable reduction ratio 3.
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z Smaller crushers give better shape in fine fractions
z ASR
Quarry Academy 2005
Important guidelines VSI
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s To get cubical products from the Merlin
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z The crusher should always be even fed
T 9 Capacity, watch up for under feeding
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c 9 Particle size distribution, well mixed
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n z 0 – fraction reduce impact crushing and increase
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l abrasion breakage which increase cubicity
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g z Max feed size ¾ of intake
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z Preferable By-FlowTM process.
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e z Can be used as fraction(s) upgrader
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Quarry Academy 2005
No cubicity Plant
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r Production 0 – 16 mm
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n Deck 2 0-2
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11-16 8-11 4-8 2-4
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Sep 16 mm
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Why ?
Quarry Academy 2005
Upgraded cubicity Plant
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r Production 0 – 16 mm
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c Deck 1
e Sep 16 mm
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e Deck 2 11-16 8-11 4-8 2-4 0-2
n Sep 25 mm
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Why ?
Quarry Academy 2005
Cubicity Plant
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r Production 0 – 16 mm
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Deck 1
T Sep 16 mm
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Deck 2 11-16 8-11 4-8 2-4 0-2
C Sep 4 mm
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Alternative?
Quarry Academy 2005
One example
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Hydrocone 3800,
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T Feed (mm) 4 – 8 mm Note
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4 – 32 15 % MF, ecc 29 mm
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g 32 – 63 31 % MF, ecc 29 mm
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4 – 63 22 % MF, ecc 29 mm
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