A Division of Due North Marketing

Due North Resources
Mining Glossary

Glossary of Mining Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

• Adit
  A tunnel driven horizontally into a hillside to provide access to a mineral deposit

• Agitation leaching
  leaching of gold from the host rock by agitating the ground ore in a cyanide solution

• Archean
  a term usually applied to the oldest Precambrian rocks

B

• Backfill
  material used to fill the space in a mine after ore has been extracted

C

• Carbon-in-leach
  a process very similar to carbon-in-pulp. In the carbon-in-leach process, the leaching and absorbing of gold onto carbon take place in the same tank
   
• Carbon-in-pulp
  a process to recover gold from a cyanide leach slurry. Coarse, activated carbon particles are moved counter-current to the slurry, absorbing the gold. Loaded carbon is removed by screening, and the gold is recovered from the carbon by stripping in a caustic cyanide solution followed by electrolysis or by zinc precipitation
   
• Cash cost
  includes production costs, royalties, marketing and refining charges, together with all administration expenses at the joint venture level
   
• Commercial production
  production for accounting purposes
   
• Cut-off grade
  the lowest grade of mineralized material considered economic; used in the calculation of the ore reserves in a given deposit
   
• Cyanidation
  a method of extracting gold grains from crushed or ground ore by dissolving them in a weak solution of sodium or calcium cyanide: also known as leaching

D

• Deposit
  means a mineralized body which has been physically delineated by sufficient drilling, trenching, and/or underground work, and found to contain a sufficient average grade of metal or metals to warrant further exploration and/or development expenditures. Such a deposit does not qualify as a commercially mineable ore body or as containing ore reserves, until final legal, technical, and economic factors have been resolved.
   
• Dip
  the angle at which a vein, structure or rock bed is inclined from the horizontal, measured at right angles to the strike
   
• Disseminated ore
  ore carrying small particles of valuable minerals, spread more or less uniformly through the gangue matter; distinct from massive ore, wherein the valuable minerals occur in almost solid form with very little waste mineral included

E

• Epithermal
  hydrothermal deposits formed at low temperature and pressure

F

• Flotation
  a process for concentrating materials based on the selective adhesion of certain minerals to air bubbles in a mixture of water and ground-up ore. When the right chemicals are added to a frothy water bath of ore that has been ground to the consistency of talcum powder, the minerals will float to the surface. The metal-rich flotation concentrate is then skimmed off the surface
   
• Footwall
  the mass of rock beneath a geological structure such as an orebody or fault
   
• Formation
  the ordinary unit of geologic mapping consisting of a large and persistent stratum of rock

G

• Gravity separation
  recovery of gold from crushed rock or gravel using gold's high specific gravity to separate it from lighter material
   
• Grinding media
  material used to finely grind ore material to a size which allows recovery of the desired contained material

H

• Hanging wall
  the mass of rock overlying a geological structure such as an orebody or fault
   
• Hectare
  an area of land equivalent to 10,000 square meters or 2.47 acres.

I

• In-fill drilling
  drilling within a group of previously drilled holes to provide a closer spaced pattern to define more accurately the parameters of the orebody

L

• Leaching
  the process in which a soluble metallic compound is extracted from ore by dissolving the metals in a solvent; see cyanidation
   
• Level
  a horizontal opening in a mine; levels are usually established at regular intervals

M

• Mineralized zone
  any mass of host rock in which minerals of potential commercial value occur

N

• Net smelter return
  an interest in a mining property held by the vendor on the net revenue generated from the sale of metal produced by the mine

O

• Operating cost
  cash cost plus depreciation and amortization
   
• Ore
  material that contains one or more minerals, at least one of which can be recovered at a profit
   
• Ounces
  troy ounces of a fineness of 999.9 parts per 1,000 parts, equal to 31.1034 grams
   
• Oxidized ore
  the alteration of metalliferous minerals by weathering and the action of surface waters and their conversion, partly or wholly into oxides, carbonates or sulfates

P

• Phyllite
  scaly minerals, micas, chlorites and clays; a term more recently applied to minerals with a layered crystal structure
   
• Porphyry
  rocks containing conspicuous phenocrysts in a fine-grained or aphanitic groundmass
   
• Precipitate
  a mixture of mineral particles filtered from solutions as a result of a chemical reaction
   
• Proterozoic
  the younger of two Precambrian systems or eras

R

• Reagent
  a chemical used in the mineral recovery process

• Reclamation
  the process by which lands disturbed as a result of mining activity are reclaimed back to a beneficial land use. Reclamation activity includes the removal of buildings, equipment, machinery, other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetation of waste rock piles and other disturbed areas
  
• Reserves
  that part of a mineral deposit which could be economically and legally extracted or produced at the time of the reserve determination. Reserves are customarily stated in terms of ore when dealing with metalliferous minerals. There are three categories of reserves:
  
  • Proven ore – material for which tonnage and grade are computed from dimensions revealed in outcrops, trenches, underground workings or drill holes; grade is computed from the results of adequate sampling; and the sites for inspection, sampling and measurement are so spaced and the geological character so well-defined that size, shape and mineral content are established.
    
  • Probable ore – material for which tonnage and grade are computed partly from specific measurements, samples or production data and partly from projection for a reasonable distance on geological evidence; and for which the sites available for inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely or to establish its grade throughout.
    
  • Possible ore – material for which quantitative estimates are based largely on broad knowledge of the geological characteristics of the deposit and for which there are few samples or measurements.

• Resource
  There are three categories of resource.
  • inferred mineral resource - a mineral resource inferred from geoscientific evidence, drill holes, underground openings, or other sampling procedures where the lack of data is such that continuity cannot be predicted with confidence and where geoscientific data may not be known with a reasonable level of confidence.
    
  • indicated mineral resource - a mineral resource sampled by drill holes, underground openings or other sampling procedures at locations too widely spaced to ensure continuity but close enough to give a reasonable indication of continuity and where geoscientific data are known with a reasonable level of reliability. An indicated mineral resource estimate will be based on more data, and therefore will be more reliable, than an inferred mineral resource estimate. Leads to probable ore reserves.
    
  • measured mineral resource - a mineral resource intersected and tested by drill holes, underground openings and or other sampling procedures at locations which are spaced closely enough to confirm continuity and where geoscientific data are reliably known. A measured mineral resource estimate will be based on a substantial amount of reliable data, interpretation and evaluation of which allows clear determination to be made of shapes, sizes, densities and grades. Leads to a proven ore reserve.
• Run of mine ore
  uncrushed ore in its natural state just as it is when blasted

S

• Semi-autogenous mill
  a mill in which rock is reduced to smaller particles partially by grinding against other pieces of rock

• Shaft
  a vertical passageway to an underground mine for moving personnel, equipment, supplies and material including ore and waste rock

• Skarn
  the metamorphic rocks surrounding an igneous intrusive where the latter has come in contact with limestone or dolomite rocks

• Spot price
  current delivery price of a commodity traded in the spot market, also called the cash price

• Stope
  the working area in a mine from which ore is extracted

• Stratigraphic
  pertaining to the composition, sequence and correlation of stratified rocks

• Strike
  the direction, or course or bearing, of a vein of rock formation measured on a level surface

• Stripping ratio
  the ratio of the amount of waste material which must be removed in an open pit to allow one ton of ore to be mined

• Sulphides
  compounds of sulphur with other metallic elements

T

• Tailings
  material rejected from a mill after the valuable minerals have been recovered

• Tertiary
  the earlier of the two geologic periods in the Cenozoic era
  
• Ton
  means a short ton (2000 pounds)
  
• Tonne
  means a metric tonne (2204.6 pounds)
  
• Triassic
  the earliest of the three geologic periods comprised in the Mesozoic era