Glossary

For help with technical exploration mining terms, an abbreviated glossary is provided below:

Assay

An analysis to determine the presence, absence or quantity of one or more chemical components.

Base Metal

A metal, such as copper, lead, nickel, zinc or cobalt.

Block caving

A method of underground mining in which large blocks of ore are undercut, causing the ore to break or cave under its own weight enabling extraction of the ore at a relatively low cost.

Breccia

Rock fragmented into angular components.

Cash operating costs/lb copper (net of credits)

Cash operating costs include a 2% net smelter return payable to a third party less by-product credits received from the sale of molybdenum, gold, silver and rhenium, divided by recovered copper over a defined period. 

CIM N1 43-101 Code

The Canadian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves sets out minimum standards, recommendations and guidelines for Public Reporting of Exploration Results, Mineral Resources and Ore Reserves. 

Circuit

A processing facility for removing valuable minerals from the ore so that it can be processed and sold.

Copper (Cu)

A ductile, malleable base metal with a myriad of uses in construction (piping, wire) and electronics due to its high electrical and thermal conductivity and good resistance to corrosion.

Copper equivalent (CuEq)

Copper equivalent is based on the value of the non-copper by-products (such as gold and molybdenum) relative to the value of copper. For example, at a long term copper price of US$2.75/lb per pound with a recovery of 87%, and a molybdenum price of US$15.00/lb with a recovery of 68%, 1 pound of molybdenum is equivalent to 4.2633 pounds of copper (Cu:Mo ratio of 1:4.2633).

Diamond drilling / drill hole

A method of obtaining a cylindrical core of rock by drilling with a diamond impregnated bit.

Diatreme

A diatreme is a breccia-filled volcanic pipe that was formed by a gaseous explosion. Diatremes often breach the surface and produce a tuff cone, a filled relatively shallow crater known as a Maar, or other volcanic pipes.

Drill core

The long cylindrical piece of rock brought to surface by diamond drilling.

Environmental Impact Study (EIS)

A written report, compiled prior to a production decision that examines the effects proposed mining activities will have on the natural surroundings.

Exploration

Prospecting, sampling, mapping, diamond drilling and other work involved in searching for ore.

Feasibility Study

A feasibility study is an evaluation of a mineral resource to determine whether it can be mined effectively and profitably. It includes the detailed study of reserve estimation, mining methods evaluation, processing technique analysis, capital and operating cost determination and the process effect on the environment and community. This detailed study forms the basis for capital estimation, and provides budget figures for the development of the project. It requires a significant amount of formal engineering work and an accuracy within 10 to 15%.

Geo-domain

Homogeneous geological domains within a deposit identified on the basis of spatial continuity of grades and geological features such as lithology, mineralogy and alteration.

Gold (Au)

A heavy, soft, ductile, malleable precious metal used in jewellery, dentistry, electronics and as an investment.

Gold Equivalent (AuEq)

Gold equivalent is based on the value of the non-gold by-products (silver, zinc, lead and copper) relative to the value of gold.  Long term prices include gold (US$1,350/oz), silver (US$25.00/oz), zinc (US$0.97/lb), lead (US$0.91/lb) and copper (US$2.75/lb). 

Grade

The amount of valuable metal in each tonne or ore, expressed as grams per tonne for precious metals and percent in the case of copper and parts per million (ppm) in the case of molybdenum. Cut-off grade – is the minimum metal grade at which a tonne of rock can be processed on an economic basis. Recovered grade – is the actual metal grade realised by the metallurgical process and treatment of ore, based on actual experience or laboratory testing.

ICP

Inductively Coupled Plasma. Analytical technique used for the detection of trace elements in soils.

Indicated Mineral Resource

An 'Indicated Mineral Resource' is that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed.

Inferred Mineral Resource

An 'Inferred Mineral Resource' is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability.

JORC Code

The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves sets out minimum standards, recommendations and guidelines for Public Reporting in Australasia of Exploration Results, Mineral Resources and Ore Reserves.

Leachable (soluble) copper

Total acid and cyanide soluble copper.

Leaching

A chemical process for the extraction of valuable minerals from ore.

Los Calatos Mining Study 

The Mining Study completed by NCL on the preferred mining scenario has been conducted at a scoping level with an accuracy of approximately 35%. 

Measured Mineral Resource

A 'Measured Mineral Resource' is that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a high level of confidence. It is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are spaced closely enough to confirm geological and grade continuity.

Metallurgy

The science and technology of extraction of metals from their ores and the refining of metals.

Mineralisation

The concentration of metals and their chemical compounds within a body of rock.

Mineralised envelope

The boundary constraining the extent of the identified mineralisation, as delineated by a nominated grade or cut-off.

Mineral Resource

A concentration or occurrence of material of intrinsic economic interest in or on the Earth’s crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.

Molydenum (Mo)

Molybdenum is commonly a by-product of copper mining. It has the ability to withstand extreme temperatures and has a high resistance to corrosion. Molybdenum is widely used as an alloy agent in stainless steel. It is also used to manufacture aircraft parts and industrial motors.

NPV

Net present value is the difference between the present value of a future cash flow from an investment and the amount of investment, where the present value of the expected cash flow is computed by discounting the cash flow at the required rate of return.

Open Pit

A mine that is entirely on surface. Also referred to as open-cut or open-cast mine.

Ore

Rock containing mineral(s) or metals that can be economically extracted to produce a profit.

Ordinary Kriging

A geostatistical method for estimating grades given a specific dataset.  Instead of weighting nearby data points by some power of their inverted distance, ordinary kriging relies on the spatial correlation structure of the data to determine the weighting values.  This is a more rigorous approach to modelling, as the correlation between data points determines the estimated value at an unsampled point.  

Orebody

Generally a solid and fairly continuous mass of ore, which may include low-grade ore and waste, as well as pay ore, but is individualised by form or character from adjoining country rock.

Oz

Troy ounce (31.1035 grams).

Pit optimisation study

Pit optimisation studies are used for open pit mine planning to determine those pit limits and mining sequences that yield maximum financial returns based on defined technical parameters, operating costs and commodity prices.

Porphyry

A rock consisting of larger crystals embedded in a more compact finer grained groundmass.

Porphyry copper deposit

A copper deposit which is associated with porphyritic intrusive rocks and the fluids that accompany them during the transition and cooling from magma to rock. Porphyry copper deposits are typically mined by open-pit methods.

PPM

Parts per million, also grams/tonne

Pre-feasibility study

A preliminary assessment of the technical and economic viability of a proposed project. Alternative approaches to various elements of the project are compared, and the most suitable alternative for each element is recommended for further analysis. Costs of development and operations are estimated. Anticipated benefits are assessed such that some preliminary economic criteria for evaluation can be calculated. Preliminary feasibility studies are completed by a small group of multi-disciplined technical individuals and have an accuracy within 20 to 30%.

Recovery

A term used in process metallurgy to indicate the proportion of valuable material obtained in the processing of an ore. It is generally stated as a percentage of valuable metal in the ore that is recovered compared to the total valuable metal present in the ore.

Reverse circulation drilling (RC drilling)

Percussion drilling method using a rotating bit and high pressure air to sample sub-surface material through the recovery of broken rock fragments ('rock chips').

Solvent extraction and electrowinning (SX-EW)

A metallurgical technique, so far applied only to copper ores, in which metal is dissolved from the rock by organic solvents and recovered from solution by electrolysis.

Strip ratio

The ratio of tonnes removed as waste relative to the number of tonnes of ore removed from an open-pit mine.