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.