Adsorb
A process where one element held in solution is attracted to and clings to another element. In gold and silver processing the precious metals within the slurry in the leach tanks are adsorbed onto granules of activated carbon.

Air samplers

Andesite
Grey to black, dense, hard, volcanic rock in its unaltered state. Contains 52-63% silica. Found around the Pacific Rim, and named after the Andes Mountain Range. At Waihi this rock hosts the quartz that contains the precious metal deposits.

ANFO

Assay
To test rock samples by chemical methods to determine the amount of precious metals they contain.

Bioavailable

Bullion
The precious metals gold and silver at all stages of the refining process once they have been removed from the ore
.

Bund
The name given to an embankment used to provide a barrier or screen. eg a noise bund or tailings impoundment bund

Carbon in pulp
(CIP) The name of the process by which gold and silver are liberated from the ore. The gold and silver are dissolved in large tanks and then adsorbed onto carbon granules.

Cascade
A series of moulds arranged like stairs into which the molten gold and silver are poured.

Cathodes
A series of negative poles or electrodes onto which the gold and silver are deposited during electrowinning.

Chain of custody

CN(free)

CN(WAD)

CN(total)

Compaction

Compression

Core drilling
Mobile drilling rigs, sometimes mounted on trucks or transported by helicopter, provide cores of rock which are analysed by geologists. The cores provide detailed information on rock formation and structure and geochemistry.

Cornish Pumphouse
The original building that housed the pump used to dewater the underground workings. The pump operated using a beam and balance system originally developed in Cornwall, England. The remains of the pumphouse still exist.

Cyanide process
The Forrest-McArthur process developed to extract gold from crushed ore. The process was originally trialled at the Crown Mine at Karangahake last century and is still in use today around the world.

dBA, dBL

Decant
To draw off or remove. The removal of water from the top of the water/solids slurry once settling of solids has occurred. At the tailings storage facilities excess water is decanted and returned to the water treatment plant.

Detoxified

Decant water

Doré
The name given to the bars of mixed gold and silver produced by the mine. These are sent away for further refining. Sometimes called doré bullion.

Downstream

Eco-sourced
Seed obtained from the area in which it is naturally growing. Eco-sourced seed is used to preserve the genetic makeup of plant populations in a particular area rather than import material from outside.

Electrowinning
The separation of materials by attraction and plating onto a surface in the presence of an electrical current.

Elution column
A tall steel tank in which super-heated water is used to wash gold and silver off the activated carbon.

Fluxes
Preparatory compounds added to the furnace to assist with the separation of impurities from the molten metal by the forming of a surface slag.

Freeboard

Frequencies

Geochemical

Geophones

Hydrocyclone
A conical liquid separator which separates material in a water slurry according to density. Hydrocyclones sort the slurry of ground ore and water according to how finely the rock has been ground.

Hydroseeding

Kilopascal

Littoral zone

Microgram

Mine water

Open pit
The void produced by open cut mining methods. Access to the bottom of the pit is gained by a haul road. The sides are shaped like gigantic steps.

Ore
Rock which contains the minerals to be mined. At Martha Mine the ore contains the minerals gold and silver.

Parameter

Peak particle velocity

Permeable

Polishing pond

Pore water pressure

Process plant
The area of the operation where ore is processed to produce gold and silver doré bars. It uses a series of physical, chemical, and electrical processes.

Quartz veins
Veins of quartz rock develop in fractures and fissures in the surrounding rock. They are deposited by saturated geothermal liquids rising to the surface through the cracks in the rock and then cooling.

Reef

Regulatory authorities

Rehabilitation
The process of returning disturbed land to a stable, self sustaining landform that is compatible with the surrounding environment.

Resource Management Act

SAG mill
A semi-autogenous grinding mill. A large rotating drum is filled with ore, water, and steel grinding balls. The result is a fine slurry. The mill is so named because the rock itself does some of the grinding.

Slag
A silica-rich froth containing impurities produced in the smelting of gold and silver. Development of slag is encouraged by the addition of especially formulated fluxes.

Stamper battery
An early form of ore crusher, the stamper battery consists of many heavy stamper heads which are raised by water power and fall under gravity into a rotary bowl containing rock to be crushed. The foundations of the Waikino stamper battery can be seen in the Karangahake Gorge between Waihi and Paeroa.

Soluble

Stemming

Storm water

Tailings

Traffic loading

Troy ounce

Under drainage water

Upstream

Volatisation

Waste rock
Rock which contains little if any precious metals in economically recoverable quantities. Waste rock is used to build the embankment which retains the tailings.