South32's Hermosa gets a US-powered boost

9th May 2023 By: Esmarie Iannucci - Creamer Media Senior Deputy Editor: Australasia

South32's Hermosa gets a US-powered boost

PERTH ( – Diversified miner South32 on Tuesday reported that its Hermosa metals project, in Arizona, has been confirmed by the US Federal Permitting Improvement Steering Council (FPISC), as the first mining project added to the FAST-41 process.

The federal government will now create a comprehensive and integrated permitting timetable for the project, which is publicly available, and within 21 days of being added to the FAST-41 dashboard, the US Forest Service will have to identify all agencies likely to have any review responsibilities and invite them to participate in the process and to set a deadline for their responses.

Within 60 days of being added to the FAST-41 dashboard, the US Forest Service has to establish a comprehensive permitting timetable, which includes intermediate and final completion dates for all federal environmental reviews and authorisations for full project development.

To qualify for the FAST-41 process, complex critical infrastructure projects must meet rigorous criteria to demonstrate benefit to the nation.

Hermosa is currently the only advanced mine development project in the US that could produce two federally designated critical minerals - manganese and zinc, which are essential minerals for powering the world’s clean energy future.

The current phase of study work for Hermosa’s Clark deposit has confirmed its potential to supply battery-grade manganese to the rapidly forming North American electric vehicle supply chain.

The Clark deposit is currently the only advanced project in the US that has a viable pathway to produce battery-grade manganese for the domestic market from locally sourced ore.

“The inclusion of Hermosa as the first mining project added to the FAST-41 process is an important milestone that recognises the project’s potential to strengthen the domestic supply of critical minerals in the US,” said South32 CEO Graham Kerr.

“The project presents a significant opportunity to sustainably produce commodities critical to a low-carbon future.”

There has been no manganese mining in the US since the 1970s and the US is now 100% reliant on foreign sources for manganese.

South32 Hermosa president Pat Risner said the company was hoping to set a new standard for sustainable mining at Hermosa, strengthening the domestic supply chain of critical minerals, growing the local economy, and improving lives in a community that needed more jobs and investment.

“Becoming a covered FAST-41 project will make the rigorous federal environmental review and permitting process for this project more transparent, predictable, and inclusive for all stakeholders. We are committed to working closely with the US Forest Service, cooperating agencies, Native American tribes, and local stakeholders in Santa Cruz County in Arizona to develop this project in a way that benefits the community, minimizes impact on the environment, and creates opportunities across the region.”

A previously completed prefeasibility study (PFS) into the Taylor deposit at Hermosa, estimated that it could produce 111 000 t of zinc, 138 000 t of lead and 7.3-million ounces of silver, with the current resource life supporting a mine life of 22 years and a nameplate capacity of 4.3-million tonnes.

The PFS estimated a capital cost of $1.23-billion of direct costs and $470-million of indirect costs to establish the first development option at Hermosa, with the sustaining capital estimated at $40-million a year.

Operating costs have been estimated at $81/t of ore milled.

A final investment decision on the Taylor deposit is due mid-2023.

At Clark, South32 has confirmed the potential to produce battery-grade manganese for the North American electric vehicle supply chain, and the company is collecting bulk samples ahead of pilot plant production of battery grade manganese from mid-2023.