EM1.4 Mining Methods

Regional Appraisal

Phase 1 of prospecting

Dredging

Underwater excavation of a placer deposit, usually carried out from a floating vessel

country rock

Waste material adjacent to a mineral deposit

wall rock

country rock boundary adjacent to a deposit

Tertiary

lateral or panel openings

Primary Openings

main opening; Shafts Declines (Slopes or ramps)Drifts or adits

Ultimate Slope

maximum slope of the pit to lower stripping ratio

Overall pit slope angle

measured between the horizontal and the line joining the top bench crest and bottom bench toe

Borehole Extraction

melting of sulfur using the steam coming out of the borehole

Solution Mining

minerals are recovered by leaching, dissolution, melting, or slurrying processes; uses chemical relationships between desired metals/minerals and the appropriate solvents

Box-cut and block cut

mining the overburden in rectangular blocks, using dozers or scrapers

Dimension Stone

natural rock material quarried for the purpose of obtaining blocks or slabs that meet specifications as to size (width, length, and thickness) and shape.

adequate supply of watersuitable waste disposal area

requirement in the development

Quarrying/ Quarry Mining

resembles open pit but benches (called faces) are lower and generally verticalused to recover dimension stone

Dip

the angle of inclination measured in degrees from the horizontal

Aqueous Mining

uniquely reliant on water or an aqueous mixture during mining and processing to recover the valuable mineral by jetting, slurrying, dissolving or melting.

Supported Underground Mining Method

uses artificial supports in mining operation

Explosive Casting

uses blasting to move a portion of overburden into area where it would normally cast

Vat Leaching

uses flooded leaching procedure; performed in vats or tanks

Caving

uses gravity to aid in mining operation

Unsupported Underground Mining Method

uses natural supports in mining operation

Pit limits

vertical or lateral extent to w/c the open pit mining may be economically conducted

Hanging wall

wall rock above a deposit

Production well

where the solution is collected

Thiobacillus ferrooxidans---> sulfide mineral

which type of lixiviant is used in Bioleaching?

Frasch process

A method of mining sulfur in which extremely hot water is pumped into the deposit, melting the sulfur so it can be forced to the surface by compressed air. No longer used in the U.S. utilizes a single well with 3 Concentric pipes outer pipes: where super heated water is injected to meth the sulfurinner pipe: where the compressed air flows and melted sulfur flows up

Injection well

A well in which fluids are injected rather than produced, the primary objective typically being to maintainreservoir pressure.

Aqeous Mining

Accounts for about 10% of surface mineral production

Drill-Charge-Blast-Load-Haul-Dump

Basic Cycle of Operation

NaCn

Common lixiviant for Gold/Silver

Sea Water/ Lake Brine

Common lixiviant for Magnesium

Water

Common lixiviant for potash/trona

ore strength: any Rock strenth: any Deposit shape: tabular, bedded Deposit dip: low, nearly horizontal Deposit size: small to large Ore grade: can be low Ore uniformity: uniform in thickness, free of partings Depth: shallow to moderate

Conditions for Auger mining:

ore strength: any Rock strength: any Deposit shape: tabular; bedded deposit dip: any, prefer horizontal or low dip Deposit size: prefer continuous deposit, large in lateral extent Ore grade: can be low if other conditions are favourable Ore uniformity: prefer uniform Depth: shallow to moderate to control stripping ratio

Conditions for Open cast Mining

Ore Strength: any Rock strength: any Deposit shape: any, but preferably deposit parallel to the surface Deposit dip: preferably with low dipdeposit size: large or thick Ore grade: can be very low Ore uniformity: prefer uniform ore, but blending can be easily implemented Depth: shallow to intermediate

Conditions for open pit mining

Ore strength: structurally sound, free from defects Rock strength: any Deposit shape: Thick bedded; massive; large in lateral extent Deposit dip: any, if thickDeposit size: large, thick Ore grade: High in physical and visual qualities Ore uniform: Uniform Depth: Shallow to intermediate

Conditions for quarrying dimension stones

Detailed Surface study

Detailed Surface study

low dilution and nonselective

Dilution and Selectivity of Auger Mining

low dilution and nonselective

Dilution and Selectivity of Open cast Mining

Low dilution and Highly selective

Dilution and selectivity of quarrying

moderate dilution and non selective

Dilution of Open Pit and selectivity

Target evaluation/ Tactical Phase

Exploration is also known as

steeply dipping, permeable and low grade deposit.

Leaching is suitable for what type of deposit?

Secondary Opening

Level or zone openings; Drifts Crosscuts Raises

Large disseminated deposits of copper, massive metallic ore bodies

Open pit is commonly used in which types of deposits

mountain top removal mining

Overburden near the top of a mountain is removed and placed in valley fills

Detailed Reconnaissance

Phase 2 of prospecting

Detailed 3-D Study

Phase 4 Exploration

Reconnaissance/Strategic Phase

Prospecting is also known as

Maximum allowable Stripping ratio

SR MAx= [Value of ore - Production Cost]/[Stripping Cost]establishes the ultimate boundary of the pit where break-even occurs

highwall mining

Sending a small, remotely controlled continuous miner into the highwallRecovery: 60%

Rib

Side wall of an excavation, also rib pillar

stratified deposits like coal and laterites

Strip Mining is usually utilized in what deposits?

Area or Contour Mining

Surface mining in which reclamation is carried out contemporaneously with extraction may be classified as _____________________.

Consolidated and permeable

The ore in Borehole extraction method should be:

Remote Sensing

The science of acquiring, processing and interpreting images and related data obtained from aircraft, satellites, and underwater instrumentation systems.

Bench Height

The vertical distance from the highest point (crest) of a bench to the toe

Stripping ratio

The volume of waste removed for each ton of ore extracted.

capping

Waste material overlying the mineral deposit

To narrow the search To increase the probability that the remaining targets will yield ore deposits To reduce risk

What are the objectives of Prospecting and Exploration?

Strip (open cast) mining

_____________________ is used for large, tabular, flat-lying ore bodies or mineral seams, such as coal, that are relatively close to the surface. Backfilling of these mines is usually economically feasible and desirable as part of the advancing mine operations.

Bench

a horizontal ledge that forms a single level of operation above w/c mineral or waste are mined.

berm

a horizontal shelf or ledge w/in the ultimate pit wall slope

auger mining

a low-cost method of recovering coal from horizontal seams by drilling into the side of a wall recovers coal or other minerals from under the highwall when ultimate stripping ratio has been achieved in open cast

Open Cast or Strip mining

a method of mining where overburden is cast directly into adjacent mined-out panels; expands sideways

Sluice

a natural trough in the ground or a metal wooden box where loosened materials are slurried in water and washed

Hydraulic Monitor (giant)

a nozzle designed to direct hydraulic energy into the the bank, connected to a supply line or header to provide a continuous flow of high pressure fluid

Casting

a process of excavation and dumping into a final location

Working Slope

a slope angle with high factor of safety so that slopes are stable during the exploitation of the deposit

Hydraulicking

a type of aqueous mining, which has been used extensively for placer deposits; involves using high pressure fluids to erode banks and loose material abd transport the material in a series of sluices

Heap Leaching

accomplished by the percolation of the lixiviant thru broken ore mass. leaching performed in a previously mined dump, tailings, or slag piles

mechanical mining methods

alternative surface mining method usually utilized for large-scale production compared to aqueous methods; utilizes mechanization for the transport of ore

roof or back

an overlying surface of an underground excavation

floor or bottom

an underlying surface of an underground excavation

Bench Slope

angle between horizontal and the line joining toe and crest of bench

Placer Deposit

any concentration of minerals that has been redeposited in unconsolidated by the action of fluid

Leaching

applicable to soluble or leachable ore deposit; chemical extraction of metals or minerals from the confines of a deposit or from material already mined

Water-injection wells

are common offshore, where filtered and treated seawater is injected into a lower water-bearing section of the reservoir.

Lineaments

are extensive linear feature on the Earth's surface that can be identified when there is a change in the topographical data.an expression of an underlying geologic structure

production scheduling

assignment of production equipment to blocks in the pit on an hour-to-hour or shift-to-shift basis

Aggregates

broad category of coarse to medium-grained particulate material used in construction

Safety Bench

collects the material which slides down from benches above, stop the downward progress of boulders

Mechanical dredges

dredges by scooping, taking up materials

Hydraulic dredges

dredges that uses water as transport medium

Direct Casting

employed in the mined-out strips

Mechanical Excavation

employs mechanical processes in a nominally dry environment to free minerals from the Earth.

in situ leaching

extraction is carried out on mineral in place

Anomaly

geologic incongruity that has the possibility of being an ore deposit

strike

horizontal bearing of tabular deposits in the deposits in the intersection with the surface

Contour mining

in hilly or mountainous terrain; cuts are placed on the contours of topography

area mining

in relatively flat terrains, cuts are made in straight parallel panels

Boxcut/Dropcut

initial surface entry for any surface opening, used to create the vertical breaking face and provides ramp access for trucks and loaders

Gloryhole Mining

involves a surface mine opening from which ore is removed by gravity thru raises connected to adit haulageways beneath, and tramming the ore to the surface on haulage level.

Long range mine planning

it is the general extraction plan for a mine on the entire life

Short range mine planning

outlines the sequence of mining that dictates the block of ore and overburden to be mined a few months or years

Open Pit Mining

process of mining any near-surface deposit by means of a surface pit-excavated using one or more horizontal benches. One of the most utilized mining methods.

Placer Mining

recovery of heavy minerals from alluvial or placer deposits using water to excavate, transport, and/or concentrate the mineral

traditional Augering equipment

recovery: 40-65%Augering machines employ drag-bit drilling heads of 2-8 ft diameter and 200-300 ft in length

Catch Bench

remnant bench used to catch unstable material; 1/3 BH

Multiple seam Mining/ Terrace Mining

removing more than 1 seam from a pit in a carefully sequenced series of steps; modification of strip mining and kind of a combination of open pit and strip mining.