1. SCREENING

2. Main feature of screening is size of particle spherical particleIrregular particle d a b c A measure of size is usually diameter

7. Size distribution A - histogram (frequency curve)

8. B - distribution curve (cumulated frequency curve)

11. Mechanics of screening P - inertia G- gravity T - friction

12. Physics of screening sliding

13. Physics of screeningcasting

14. Movevent of particle with casting (ejection)

15. Probability of screening P screning = P z P s P r H - thickness of particles on screen d r - screen aperture

16. Kinetics of screening i,t =  i exp (–k i t) v p i = –d i /dt = k i i, For instance Malewski, 1990: Generally: - velocity of screening k - rate constant, t - time k 0,5 = 3600 VBW  sCd s /Q o, (for meaning of symbols see „Podstawy mineralugii, 2001”) - content of a fraction in the product on the screen d t -screen aperture  - constant d i - particle size k 0.5 -rate constant for d i = d t

18. Particle size analysis

20. Basic screen types and their classsification (Kelly and Spootiswood)