Name and Location
Zandkopsdrift rare-earth element project, Northern Cape, South Africa.

Client
Frontier Rare Earths and Korea Resources Corporation (Kores).

Project Description
Zandkopsdrift has one of the biggest total rare-earth oxide (REO) grades and the highest-grade REOs of significantly advanced rare earths deposits outside China.

Envisioned is a standalone opencast mine, which will be mined by conventional free-dig and/or drill, blast and haul techniques, with minimal drilling and blasting required. The steady-state mining production target is one-million tons a year and the total separated rare-earth oxides target production rate is 20 000 t/y.

Infrastructure associated with the mine and process plant includes the upgrade of existing district roads from the surrounding towns to the mine.

Frontier will supply water to the mine from demineralised water, piped 35 km from a desalination plant.

On-site power will be supplied by State-owned utility Eskom and on-site power generators from various sources.

The desalination plant will be powered by diesel generators and the Saldanha separation plant will be supplied by State-owned power utility Eskom.

Value
$910-million, which includes capital expenditure requirements for the Zandkopsdrift mine, related infrastructure and services, land purchases, mine closure and rehabilitation provision, the upgrading of local district roads, the provision of the social and labour plan, as well as the Saldanha separation plant (SSP), with its related infrastructure and services.

Duration
Along with its strategic partner, Kores, Frontier intends to start rare earths production in 2016, with a target production capacity of 20 000 t/y of separated REOs.

Latest Developments
All of the individual consultants’ reports for the PFS, which cover all aspects of the proposed Zandkopsdrift development, including the design of the Zandkopsdrift processing plant (ZPP) and SSP, power, water, roads, tailings, mining, reagent supply, logistics and environmental management, were completed on schedule and presented to the company for review in 2013. The review identified several areas where potential engineering design and process improvements could be made that could have a potentially significant positive impact on the capital and operating cost estimates for the ZPP and the SSP.

Testwork was undertaken in the fourth quarter of 2013 and the first quarter of 2014 with the aim of validating the potential improvements that were identified, and, based on positive results from this work, the PFS flowsheet was revised and finalised in the second quarter of 2014.

Engineering design work for the PFS has started based on this flowsheet, following which the PFS will be concluded. The results of the PFS are expected to be announced in the fourth quarter of 2014.

As about 97% of the rare earths at Zandkopsdrift are contained in monazite, for which a sulphuric acid cracking process has been widely used on a commercial scale for many years, the sulphuric acid process has been used as the basis for the flow sheet for the ZPP.

The following process flow is the basis for the engineering design work currently being undertaken:
• a front-end crushing and milling circuit. The selected milling technology  produces a sharply defined particle size distribution, with downstream handling benefits.
• an impurity preleach circuit, which provides a significant mass reduction and removes manganese with low rare earth losses, and a consequent reduction in capital and operating costs of the cracking and other downstream processes.
• an acid contacting circuit in which concentrated sulphuric acid is mixed with the feed material to produce a free flowing feed for the cracking circuit.
• a two-stage cracking and impurity stabilization circuit in which the prepared feed is baked at elevated temperatures, which decomposes the rare-earth minerals, recovers sulphur as sulphur dioxide and sulphur trioxide. This is returned to the sulphuric acid plant and stabilises many of the impurities, which prevents them from leaching with the rare earths in the water leach circuit.
• A water leach circuit, in which the calcine is water leached to produce a pregnant leach solution (PLS) containing rare-earth elements (REEs) and residual unstabilised impurities.
• an impurity removal circuit in which the PLS is purified by removal of the residual unstabilised impurities through precipitation and filtration.
• a REE precipitation circuit in which the REEs are precipitated from the purified PLS as a mixed rare earth product that is suitable for processing through a conventional solvent extraction separation plant.
• A final stage of waste neutralisation and disposal to the tailings storage facility on site.

Key Contracts and Suppliers
Venmyn SNC-Lavalin (preliminary economic assessment); Mintek and SGS Mineral Services (metallurgical flow sheet development); the MSA group (resource estimation); Sound Mining Solutions (mine design and schedule); Epoch Resources (design of tailings disposal facility); SNC Lavalin (separation plant engineering design and capital operating cost estimates) and DRA (engineering design and operating-cost estimates for Zandkopsdrift).

On Budget and on Time?
Project is on schedule

Contact Details for Project Information
Frontier Rare Earths (Luxembourg), tel +352 208 80249 or email ir@frontierrareearths.com.