Update on Geothermal Mineral Extraction – New Zealand’s Journey

Abstract

The opportunity for geothermal minerals in New Zealand was first suggested in the early 1960s, with the first work on silicates and lithium undertaken by government scientists at Wairakei in the 1980’s. In the 1990’s, the Electricity Corporation of New Zealand and Tasman Pulp and Paper ran extensive silica extraction pilot plant trials, and Pacific Lithium began investigating the extraction of lithium at a laboratory scale. It was recognised that more work was required to realise value from minerals in geothermal water, and in 2012 GNS Science proposed an applied research programme ‘From waste to wealth: Commercial recovery of products from geothermal fluids’ which sought to identify impediments to business adoption of geothermal fluid mining processes. The Ministry of Business Innovation and Employment (MBIE) funded the research. This foundation study identified effective processing methods for likely target products, and provided greater understanding of the economic viability, market drivers, and the regulatory framework influencing business in the implementation of such technologies in New Zealand. The research and ideas generated gained the interest and support of geothermal production companies, regional councils, Māori trusts, regional development groups, and other industries. An integrated research proposal, supported by industry, was submitted into the 2016 and then 2017 New Zealand Government contestable research funding round, but both were declined funding. Subsequently some work has been undertaken; including by GNS Science in a review of rubidium and cesium extraction methods; and by Geo40 extracting silica on a commercial demonstration scale using fluids from the Contact Energy managed Ohaaki Geothermal Field, using ultrafiltration technology. Also MBIE, in conjunction with the geothermal sector, have commenced a review of the legislation influencing mining species from geothermal fluids. This work is aimed at clarifying and removing ambiguity and potential conflict in the applicable statutes. New Zealand is underway to realise commercial value from the minerals in solution in geothermal waters. This paper provides updates, examples and experiences on the New Zealand geothermal minerals journey