HOW IT'S MADE
Rorison's Aria quarry is the only quarry in the North Island producing serpentine which, when crushed, is a rich source of magnesium used for either direct application to pastures and crops or as a mix with other fertilisers.
The limestone quarried occurs on both walls of the serpentine deposit and is excavated to facilitate access to the serpentine at deeper levels.
In order to access both the limestone and serpentine, removal of clay and mudstone over-burden is required.
EXTRACTION OF LIME
To extract lime, the limestone must first be drilled and blasted to pre-fracture the rock, ready for loading. Dump trucks are loaded with the rock by diggers and then excavated material is carted to the limestone stockpile, adjacent to the lime plant. The rock is then transferred into hoppers by a loader to start being processed.
PROCESSING THE LIMESTONE
Limestone is fed directly into the lime plant through a primary crusher which feeds directly into a mill. From the mill the lime is directed either straight into storage bins or through a screen system which seperates the product into Aerial Lime and fines. The fines are either sold directly for industrial uses or mixed back into the normal agricultural lime product. All the products are conveyed to storage bins before being loaded into trucks for transport to the end user.
EXTRACTION OF SERPENTINE
Serpentine is excavated by diggers which load the rock into dump trucks. The Serpentine is then taken to an undercover stockpile, adjacent to the Serpentine plant. This ensures the product remains dry and gives enough volume to operate 24 hours per day. From the storage facility, the Serpentine is loaded into a hopper in order to begin being processed.
PROCESSING THE SERPENTINE
From the hopper the serpentine passes through a primary crusher and is then conveyed into the plant where it passes through a hammer mill. From the serpentine plant the product is conveyed to load out bins for direct loading into trucks for transport to the end users, or mixing with the lime to produce LimeMag before being sold.
