1.03k likes | 1.4k Vues
Liberation, Separation, Extraction. MINE 292 - Lecture 3. Liberation, Separation, Extraction. STAGE 1 – Blasting (600-650 mm) STAGE 2 - Primary Crushing (100-250 mm) STAGE 3 - Secondary Crushing (12-19 mm) STAGE 4 – Grinding (100 microns) STAGE 5 - Separation by size
E N D
Liberation, Separation, Extraction MINE 292 - Lecture 3
Liberation, Separation, Extraction STAGE 1 – Blasting (600-650 mm) STAGE 2 - Primary Crushing (100-250 mm) STAGE 3 - Secondary Crushing (12-19 mm) STAGE 4 – Grinding (100 microns) STAGE 5 - Separation by size STAGE 6 - Separation by values STAGE 7 - Extraction of values
What is an Ore? • Mineralized rock that can be mined/processed • At a time (temporal) • At a place (spatial) • At a profit (economic) • Waste rock can become an ore • Tailings can become an ore
Drilling and Blasting • Creates a top size suitable for transportation • Begins the process of Liberation • Factors • Drill hole diameter • Drill hole spacing and pattern • Explosive type • Delay system
Influence of Blasting Practices S. Morrell and W. Valery, 2001. “Influence of Feed Size on AG/SAG Mill Performance”. SAG 2001, Vancouver, Canada, pp203-214 S. Morrell, 2003. “The Influence of Feed Size on Autogenous and Semiautogenous Grinding and the Role of Blasting in its Manipulation”, Proc. 22nd International Mineral Processing Congress, Eds.: L.Lorenzen and D.J. Bradshaw, p.526-533.
Influence of Blasting Practices S. Morrell and W. Valery, 2001. “Influence of Feed Size on AG/SAG Mill Performance”. SAG 2001, Vancouver, Canada, pp203-214 S. Morrell, 2003. “The Influence of Feed Size on Autogenous and Semiautogenous Grinding and the Role of Blasting in its Manipulation”, Proc. 22nd International Mineral Processing Congress, Eds.: L.Lorenzen and D.J. Bradshaw, p.526-533.
Influence of Blasting Practices So, an increased Power Factor of 0.6 kg/m3 yields 250 t of increased production and a decrease in average grinding energy of 1.4 kWh/t Bulk Density: 1 m3 of ore = 2.03 t (ore S.G. = 2.9) Increased explosives use (kg/t) = 0.6 kg / 2.03 t = 0.296 kg/t Increased cost = 0.296 kg/t x $1.06/kg = $0.313 kg/t Explosive cost increase = $0.313 x 250 t = $78.33 Decreased energy cost = $0.10/kWh x 1.4 kWh/t x 250 t = $35.0 Total cost increase = $78.33 - $35.00 = $ 43.33 Increased ore value = 250 t @ $5.26* / t = $1,315 * 0.4 %Cu = 3.6 kg recoverable Cu / t x $7.3 /kg x 0.2 = $5.26 / t
Order of Comminution Processing Blasting Primary Crushing Secondary Crushing Grinding Regrinding
Grinding Mills Rod Mill – opened up for maintenance Ball Mill – overflow type
Grinding Mills Bingham Canyon Grinding Mills
Grinding and Cyanide Leaching Musslewhite Mine, Ontario