Stockton mine


Located in the Buller Coalfield on the West Coast, Stockton is the largest opencast mine in New Zealand.

The mine delivers high-quality steelmaking coal for export.

We play a small part in the overall global seaborne coal trade, with exports of New Zealand coking coal  expected to represent approximately 0.38 percent of the total 263 million tonnes estimated by S&P Global Platts to trade on the seaborne market in 2021.

The onboarding of a new customer is also a lengthy process. Because our coal does not run to standard coking coal specifications, we work alongside our customers over an extended timeframe as they re-design their own coking coal blend to work around our product.

So why is there a demand for our coal?

The answer comes down to two unique aspects of our export coking coal – high vitrinite and low ash.

Vitrinite (from the woody parts of plants) acts as a binding agent in the coking coal blend, balancing infusible inertinites to optimise strength. An analogy is the way in which cement (vitrinite) and aggregate (inert components) are required in the right proportions to make strong concrete.

Low ash means less heat is wasted on melting impurities, less flux (to assist melting the ash) is required, and the slag rate is lower. Reduced ash also generally improves coking coal strength by reducing impurities.

As a result of the high vitrinite and low ash, quality is improved and the amount of fuel (coking coal and pulverised coal injection) required to produce a tonne of steel is reduced. Reducing the amount of fuel required gives our customers an immediate commercial benefit by reducing their coal purchases. Crucially it also reduces the CO2 emissions incurred to produce the same amount of pig iron.


Miners beside truck

Stockton location on map

Mine information

  • Ownership
    65% BRL 35% Talleys Energy
  • Location
    35 km north of Westport
  • License/Permit
    CML 37150, CMP 52937 and CMP 41515
  • Coal types
    Bitiminous, coking coal, thermal
  • Life of mine
    10+ years
  • Coal Reserves
    6.4 Mt
  • Coal Resources
    63.4 Mt
  • Last FY production
    913 kt