Characterization for simulating flotation plants: kinetic parameters by grade and size

Authors

• • •

Keila L. Gonçalves a , Claudio L. Schneider b* , Ronald H. Rojas b & Marisa M.Monte

b

(a) Vale – Centro de Desenvolvimento Mineral, Brazil (b) CETEM – Centro de Tecnologia Mineral, Brazil

MOTIVATION Design and scale-up of flotation plants for Green Field projects at Vale’s CDM • • • • Copper ores Iron ores Apatite ores Other projects

• • • • OBJECTIVES To establish a procedure for complete characterization of kinetics parameters for pre-determined conditions: “the soup” To be able to measure hydrodynamic parameters (bubble size distribution) To be able to simulate Mini Pilot Plant test results To be able to scale-up for industrial flotation

THE MODEL

THE MODEL AS IMPLEMENTED IN MODSIM

THE MODEL PARAMETERS

THE MODEL PARAMETERS ANGLO PLATINUM BUBBLE SIZER Bubble size distribution and bubble residence time

THE MODEL PARAMETERS CPP Mini-Pilot Plant Froth transmission coefficients Calibration of flotation parameters

THE MODEL PARAMETERS All kinetics parameters

KINETIC PARAMETERS PROCEDURE • Run a preliminary kinetics test to determine optimum flotation times • Run repeated kinetics tests at optimum flotation times to produce enough material in each time interval • Make composite samples of each time interval and sinks • Sieve each time interval and sinks in  2 size intervals • Analyze each time-size fraction in the MLA to determine the contribution of each particle type • Calculate all kinetics parameters

KINETIC PARAMETERS ANALYSIS Particles that floated between 10 and 20 seconds Conditional on size distributions

KINETIC PARAMETERS ANALYSIS 100 90 80 70 60 50 40 30 20 10 0 0 0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100 212x150 150x106 106x75 75x53 53x38 Particles that did not float after 120 seconds Conditional on size distributions

MEASURED FLOTATION RATES 7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

0 10 20 30 40 50 60

Average particle grade, %

70 80 90 100 212x150 150x106 106x75 75x53 53x38

100 MEASURED ULTIMATE RECOVERIES 90 80 70 60 50 40 30 20 10 0 0.00

10.00

20.00

30.00

40.00

50.00

60.00

Average particle grade, %

70.00

80.00

90.00

100.00

212x150 150x106 106x75 75x53 53x38

CONCLUSIONS • We don’t see fundamental flotation rates (as by definition) because transport controls the process of production. (particles and bubbles rise much slower than the attachment-detachment processes) • Ultimate flotation recoveries control the selectivity of the flotation for this system.

• Particles of about 212 microns are unfloatable • Recovery is maximum for particles smaller than 53 microns.

ACKNOWLEDGEMENTS This work has been sponsored by Vale and CNPq

QUESTIONS?