PanAust Limited has reported an update=d Mineral Resource estimate for the rich Nena copper-gold deposit within the world class Frieda River Project in Papua New Guinea.
The Nena deposit is located approximately five kilometres (km) north-west of the Horse – Ivaal-Trukai, Ekwai and Koki (HITEK) copper-gold deposits that form the basis for the Frieda River Copper – Gold Project feasibility study and PanAust says Nena is envisaged as an additional mining and processing operation that would be developed after the HITEK deposits commence production.
The Nena deposit is divided into two zones, a sulphide zone and an outcrop ping highly weathered gold cap zone. The new resource estimates are:
• The Nena sulphide Mineral Resource contains an estimated combined Indicated and Inferred Mineral Resource of 52 million tonnes (Mt) at a grade of 2.13% copper and 0.63 grams per tonne (g/t) gold.
• The Nena gold cap Mineral Resource contains an estimated combined Indicated and Inferred Mineral Resource of 20 Mt at a grade of 1.32g/t gold.
The Mineral Resource estimate is based on data from 211 diamond core drill holes totalling approximately 46,900 metres (m) and builds on the work performed by previous owners of the Frieda River Copper-Gold Project. Two additional variables (iron and sulphide sulphur) have been incorporated in the estimate to allow metallurgical modelling.
The Frieda River Copper-Gold Project is held by the Frieda River Joint Venture, an unincorporated joint venture between Frieda River Limited (FRL) , a wholly owned subsidiary of PanAust, and Highlands Frieda Limited, a wholly owned subsidiary of Highlands Pacific Limited. Frieda River Limited manages the Project and holds an 80 per cent interest; Highlands holds the remaining 20 per cent interest.
The deposits of the Frieda River Copper -Gold Project, including the Nena deposit, together represent one of the largest undeveloped copper -gold deposits in the world.
Strategic development opportunity
PanAust says the Nena Mineral Resource offers a strategic development opportunity to increase the value of the Frieda River Copper-Gold Project. The Nena deposit is located in close vicinity to the HITEK copper – gold deposits that were the subject of the 2016 feasibility study.
It said the facilities and infrastructure required to develop the HITEK deposits will also facilitate the exploitation of the Nena Mineral Resource.
The depth, distribution and nature of the Nena mineralisation favours a staged development approach. The deposit is amenable to open-pit mining with the potential for underground mining at depth. Open – pit mining would initially extract t he near surface gold cap mineralisation to expose the sulphide rich portion of the deposit.
Gold recovery by leaching methods will be considered for this first development stage. Mining and processing of the more complex sulphide Mineral Resource is contemplated as the second development stage. Under this concept a new flotation and hydrometallurgical plant would integrate with the processing circuit e stablished to treat the Nena gold cap mineralisation.
Future work program
The current drill coverage indicates that extensions to the Nena deposit are unlikely and there are no immediate plans for further exploration or resource definition work. However re cent geophysical re – interpretation has identified multiple buried high sulphidation epithermal targets . A porphyry style deposit to the north of Nena has also been proposed as a n e xploration concept.
Future desktop studies will be undertaken to assess the most appropriate approach to mining and processing mineralisation from the Nena deposit.