analysis of a banana screen using edem and ansys - ESSS

ANALYSIS OF A BANANA SCREEN
USING EDEM AND ANSYS
José Cleber Rodrigues da Silva, VALE
Daniel Schiochet Nasato, ESSS

SUMMARY
• Overview – Vale
• Introduction
• Objectives
• Material flow and forces analysis
• Conclusion

Overview – Vale
• Vale is the world leader in iron ore and pellet production and the second
biggest nickel producer.
• Operating through offices, operations, exploration projects and joint
ventures, we are the second largest diversified mining company in the
world and the biggest in the Americas by market capitalization.
Headquartered in Brazil, we operate in 35 countries on five continents
and employ over 60,000 people across the world.
• We are present in Colombia, Chile, Argentina, Peru, Paraguay, Canada,
the United States, Barbados, France, Norway, Switzerland, the United
Kingdom, Angola, Zambia, Mozambique, Guinea, South Africa, the
Democratic Republic of the Congo, Gabon, India, China, Mongolia,
Oman, Kazakhstan, Japan, South Korea, Taiwan, the Philippines,
Thailand, Singapore, Indonesia, Malaysia, Australia and New Caledonia,
in addition to Brazil

Our beliefs
• Our mission
To transform mineral resources into prosperity and sustainable development.
• Our vision
To be the largest mining company in the world, and to surpass the established
standards of excellence in research, development, project implementation and
business operations.

Northern System
• Consists of an integrated mine-railway-port system, which is made up of open-pit
iron ore mines, an industrial treatment plant by the Carajás Railway (which is 892
km long) and the sea terminal of Ponta da Madeira, in São Luís. From this
terminal, the iron ore of Carajás is exported to clients all over the world.
• Discovered in 1967, the Mineral County of Carajás has iron ore reserves of
approximately 16 billion tones. The high quantity and quality of the ore allows for
a majority of the iron ore products to be generated solely through the stages of
grinding and classification.
• Carajás has a production capacity of 100 million tones per year (Mat). To ensure
the granulation adequacy of the products, the beneficiation plant is equipped with
machines for grinding, humid sieving and classification of the ore. The ore goes
through the following stages of production: primary crushing, secondary crushing
and sieving, tertiary crushing and sieving, grinding, cycling and finally, the filtering
of pellet feed. The objective of the beneficiation plant is to obtain three different
grain thicknesses from the iron ore: pellet feed, sinter feed and granulated.

Introduction
• Vibrating screens are crucial on a mining plant;
• Iron ore coming from crushing must be classified through a
vibrating screen;
• Structural problems on the screen may be caused through
an incorrect or excessive feed;
• EDEM simulations will be applied to help identifying
problems related to incorrect feeding;

Objectives
• Calculate separation efficiency, material height on the screen
and material velocity profile;
• Check if mass flow is appropriate;
• Calculate forces on screen surface for further structural
analysis with ANSYS.

Material data and initial conditions
Material data Ore Rubber Steel
Poisson's Ratio 0.25 0.25 0.25
Shear Modulus 1,00E+06 1,00E+08 7,00E+10
Density 4250 1300 7800
Interaction data ore/ore ore/rubber ore/steel
Coeff of restitution 0.2 0.3 0.3
Coeff of static friction 0.6 0.65 0.5
Coeff of rolling friction 0.25 0.25 0.2
• Particle size distribution: 10 to 100 mm diameter
• Mass flow: 4200 ton/h
– 20 hours to simulate 18s in a dual core machine
– About 280000 particles on domain

Dynamics
• 7mm displacement
• 880 rpm

Material height and size profile
• Particles are colored by mass • A slice was applied in the sieve
• Average 115mm material height

Size analysis by regions
Withheld
Passing
• The screen was split into passing and withheld material;
• Small particles separation was analyzed.

Small particles
• Withheld small particles:
• About 14% of small particles are
withheld
• Passing small particles
• 86% of small particles pass
through the sieve

Force profile
• Total force on the screen was calculated:
• Reached up to 170 KN

Velocity profile
• Velocity profile on screen.

Velocity on bin group
• Bin group on screen.
• Average velocity on bin group:
• 0.76 m/s on flow direction (x)

Conclusions
• EDEM captured material flow through the sieve;
• Some small particles are being withheld in the sieve:
– Can be caused by an excessive feeding
• Forces on the screen were calculated on EDEM;
• These forces will be used in ANSYS to evaluate possible
structural failures on screen due to incorrect material flow.