Question bank: Modeling and Simulation of Mineral Processing Systems

Mineral Processing – Question Bank

1. Explain the steps involved in developing a plant flowsheet simulation using a commercial simulator.
2. The breakage function for a crusher is given by:
   
   B(x:y) = 0.5 (x/y)^0.6 + 0.5 (x/y)^3.0
   
   where x is the size of progeny particle and y is the size of parent particle.
   Size class 3 has mesh size boundaries of 12.0 cm and 8.0 cm, and size class 6 has mesh size boundaries of 4.0 cm and 2.0 cm.
   
   Calculate b₆₃, the fraction of material from size class 3 that reports to size class 6 after crushing.
3. Define mathematical modeling. Explain its importance in mineral processing systems with suitable examples.
4. Calculate the settling velocity of a spherical particle of size 0.12 mm in water using Stokes’ law. Given:
   Particle density = 2750 kg/m³
   Fluid density = 998 kg/m³
   Viscosity = 0.001 Ns/m²
5. Explain the Rosin–Rammler size distribution equation. Define its parameters and state its significance.
6. What is breakage function? Explain its physical significance.
7. A hydrocyclone has a corrected classification curve given by:
   
   e(d_p) = 1 / (1 + x^SI), where x = d_p / d_50c
   
   When processing a feldspar slurry, the corrected cut size is d_50c = 20 µm and the sharpness index SI = 0.80.
   The hydrocyclone is then used to treat a hematite slurry under similar operating conditions.
   
   Given:
   Density of feldspar = 2550 kg/m³
   Density of hematite = 5200 kg/m³
   Recovery of water to underflow = 20%
   
   Calculate the recovery of 12 µm hematite particles to the overflow.
8. Explain particle size classification and its importance in mineral beneficiation circuits.
9. Using Kick’s law, estimate the energy required to reduce size from 80 mm to 20 mm. Given K_k = 3.5 kJ/kg.
10. With the help of the Karra model, explain the prediction of vibrating screen performance. Discuss the design and operating factors influencing screening efficiency and capacity.
11. Explain the modeling of dense media separators, highlighting their advantages.
12. What are progeny particles? Briefly explain the mechanisms of shatter, attrition, and cleavage in particle breakage processes.
13. Draw a rod & ball mill circuit and explain its simulation.
14. Explain the population balance approach used in modeling comminution processes.
15. A vibrating screen having an aperture size of 5 mm is used for size classification of mineral particles. For this screen, the cut size (d₅₀) predicted using the Karra model is 3.2 mm, and the sharpness parameter (m) is 4. Determine the probability of passing for particles of size 4 mm. Comment on the result.
16. Explain the Plitt model used for hydrocyclone performance prediction.
17. List the types of standard simulators available in mineral processing and their features.
18. Calculate the energy required to reduce particle size from 50 mm to 12.5 mm using Kick’s law, given K_k = 3.2 kJ/kg.
19. Draw and explain a typical particle size distribution (PSD) curve.
20. Explain the classification efficiency curve of a hydrocyclone and define sharpness index.
21. A crusher product is analyzed and found to have the following Rosin–Rammler parameters:
    D_63.2 = 40 mm
    λ = 2.0
    
    What percentage of the material is smaller than 20 mm?
22. Explain Kick’s energy equation used in comminution processes.
23. Explain the Lynch model used for predicting hydrocyclone performance.
24. List and explain the basic concepts involved in ore dressing plant simulation.
25. Draw and explain a closed-circuit grinding system and its simulation steps.
26. Explain the different phases in flotation.