Quiz 1 Flashcards
Surface Mining Techniques : Name the 7 types of surface mining?
- Open Pit
- Strip Mining
- Quarrying
- Highwall (Auger)
- Mountaintop
- Placer
- Solution Mining
Surface Mining Techniques : For which type of geological deposits are open pit mostly used
- vein type
- disseminated metallic ores (hard rocks)
- erratic stratigraphic units
Surface Mining Techniques : In open-pit when does reclamation start?
Until almost all ore production is completed
Surface Mining Techniques : What are the advantages (2) and disadvantages(3) of the conventiional pushback
A:
1. allows to perform larger areas
2. more flexible and less complicated road design
D:
1. NPV to be generated will be less
2. less flexibility in scheduling operations
3. less opportunity to blend ores
Surface Mining Techniques : What pratice is shown here?
Sequential Pushbacks
Surface Mining Techniques : What characteristics is strip mining ideally applied to?
- relatively horizontal (tabular)
- bedded
- shallow
- uniform
- Continuous
Surface Mining Techniques : What is the main indicator of performance for strip mining?
stripping ratio (tonne of waste rock per tonne of ore)
Surface Mining Techniques : In what are strip mine is typically divided into?
long rectangular blocks (sometimes referred to as panels) that are mined in sequence
Surface Mining Techniques : Name main characteristics 3 of strip mining?
- Production rates are high (economies of scale)
- Safety is high
- excavation and loading can be conducted in a continuous way
Surface Mining Techniques : What is contour mining?
Strip mining narrow zones in a mountainous terrain
Surface Mining Techniques : Name the 3 types of contour mining?
- Haulback
- Box-cut
- Blockcut
Surface Mining Techniques : Describe haulback contour mining.
overburden material is hauled by trucks and placed directly in the void created by the removal of coal. Highwalls are eliminated and near original surface is restored
Surface Mining Techniques : Describe box-cut contour mining.
Box-cut or terrain is created through overburden to access to seam. This
box is extended along with strike direction
Surface Mining Techniques : Describe block-cut contour mining.
In this method, overburden blocks, which are wider than 20 m, are removed as
a unit and disposed in mined-out voids.
Surface Mining Techniques : Why do we want keep the stripping ratio as constant as possible?
Since equipment and coal processing unit have constant capacities, a change in stripping ratio will cause capacity utilization issues.
Surface Mining Techniques : Give the break-even Stripping Ratio formula.
Surface Mining Techniques : Give the overall Stripping ratio formula.
Surface Mining Techniques : Name the 2 types of Quarrying activties.
- Aggregate mining (e.g., construction materials (gravel and sand))
- Dimension stone mining (e.g., marble, slate)
Surface Mining Techniques : Name the 5 factors affecting quarry selection since quarried material is cheap
- Large overburden removal cost cannot be paid off
- There should be sufficient reserve
- There should not be a dewatering cost
- Resource should be close to the market
- Environmental problems should be kept in minimum
Surface Mining Techniques : In Quarrying for Dimension Stone how is the Rock is cut (6) ?
- Diamond wire saw
- Jet burning
- Diamond saw blade
- Laser cutting
- Water jet
- Drilling and blasting
Surface Mining Techniques : What the 2 Criteria used for sawability?
- Cutting or production rate of stone blocks and slabs in m2
/h. (determined by rock properties) - Wear rate of diamond tools
Surface Mining Techniques : When is Auger and Highwall Mining used?
When contour strip mining has been completed and the removal of overburden to access additional coal no longer becomes economically feasible
Surface Mining Techniques : What is the most challenging part of mountain top mining?
the development of roads to access the areas that will be mined
Surface Mining Techniques : Name envionmental downsides of mountain top mining (3)?
- Mined area cannot be reclaimed or restored to original ground in an easy way
- Clearing before blasting leads to removal of trees and vegetations
- It causes biodiversity loss and adverse effect on water quality
Surface Mining Techniques : What is a placer?
Placer is a gravel deposit in heavy minerals, especially gold particles and gemstones
Surface Mining Techniques : What is placer mining?
Placer mining comprises various mining methods using water to recover valuable ore from the surrounding sediment