Measures of Dispersion and Variability: Range, QD, AD and SD
Unit operations of mining
1. •These are basic steps employed to produce mineral from
deposit.
•Theses are of two types
1. Production operations
Steps contributing directly to mineral extraction
2.Auxiliary operations
Steps which support the production cycle
2. Unit operations of mining
Unit operations involved in production cycle are
divivded in two groups
1. Rock breakage(by drilling and blasting)
2. Material handling(loading,hauling,hoisting)
4. Unit operations of mining
Surface mining
Several inches hole drilled
Charge inserted
Blasted to reduce ore to fragments
Broken material loaded by excavators
Haulage unit may be trucks ,belt conveyor, rail road
cars.
In dimension stone blocks are freed by saws without
blasting.
6. Unit operations of mining
Underground mining
Smaller drill holes
Special machinery
Production cycle same as surface mining
Auxiliary operations
Roof support
Ventilation
Power supply
Pumping
Maintenance
Lighting
Communications etc
Waste disposal
In suface the first two are not necessary