Ravensthorpe Nickel Operations (RNO) consists of several discrete nickel laterite deposits.

The mineral resources defined at the Halley's, Hale-Bopp, Shoemaker-Levy, Nindilbillup and Shoemaker-Levy North nickel laterite deposits have developed over Archaean ultramafic rocks through prolonged deep weathering. Sub-horizontal tabular zones containing residual and supergene accumulations of nickel, cobalt, manganese and iron have developed in association with extensive leaching of principally magnesium.

The majority of nickel mineralisation in the RNO deposits is hosted in the goethite/limonite zone, whilst the upper levels of the saprolite zone is also commonly well mineralised. In all RNO deposits, nickel mineralisation forms as a blanket beneath barren surface units whilst cobalt mineralisation occurs mainly in a narrow zone generally towards the top of the nickelenrichment zone in association with manganese accumulation. It is often centred around the redox boundary in the limonite zone, recognised by an accumulation of manganese enrichment.

Ravensthorpe Nickel Operation (RNO) was placed on care and maintenance in October 2017 and restarted in Q1 2020. Nickel production activities recommenced in May 2020, with full production levels expected during Q4 2021 following the commission and ramp up of the Shoemaker Levy project. RNO operates with conventional open cast mining using hydraulic excavators and mechanical drive haul trucks.

Ore will be mined at Shoemaker Levy deposit using conventional mining techniques similar to those used at Halleys and Hale-Bopp. Limonite and Saprolite ore will be hauled to a new primary crushing station at Shoemaker-Levy and conveyed approximately 9 km to the existing processing facility.

At Shoemaker Levy, mining operations will commence in Q1 2021 and the overland conveyor and primary crusher will be commissioned and ready for use in Q2 2021. Shoemaker Levy will be mined in a series of phases over the next 20 years.

RNO has fully equipped training facilities for operators and maintenance workshops on site. Waste is trucked onto waste dumps in the vicinity of the open pits.

Nickel and cobalt values are enriched in the fines fractions of both the limonite and Saprolite ores, and the beneficiation process consists of rejecting the principally siliceous coarse fractions using conventional wet ore sizing equipment. Typical mass rejections of 60-70% are achieved at a nominal nickel recovery of 60-65%.

Crushed ore to each Beneficiation circuit is recovered from its respective reclaimer stockpile. Both feeds direct the crushed ore to a drum scrubber, where loose ore agglomerates are broken up and dispersed, and any loosely attached mineralisation is scrubbed from the siliceous gangue. The scrubber product is treated through a combination of screening and hydraulic classification to recover the nickel and cobalt values, which are now concentrated in the -100µ fraction. The +100µ material is discarded to a reject stream which is mechanically transported to a dump.

A new primary crushing facility will be constructed at Shoemaker-Levy mine area to reduce the Run of Mine (ROM) ore to a smaller average particle size which will allow for overland conveying.

The crushing facility at Shoemaker-Levy will be similar to the existing facilities at RNO. The existing crushing facility at RNO consists of a 400 tonne ROM bin with apron feeder. The apron feeder feeds ROM ore through a vibrating grizzly. The vibrating grizzly diverts undersize material to a mineral sizer and oversize material to a jaw crusher and a second mineral sizer. The primary crushed material will then report to the proposed overland conveyor. It is expected that the crushing facility at Shoemaker-Levy will consist of a similar sized ROM bin, apron feeder and two mineral sizers and potentially no jaw crusher making the facility at Shoemaker-Levy more compact than the existing RNO crushing facilities.

Limonite and Saprolite ores will be conveyed in batches from Shoemaker Levy to the existing RNO plant and fed through the crusher in separate batches according to operational requirements. As a result, the expected throughput for the crushing facility and overland conveyor is expected to be nominally 2,500 tonnes per hour (tph) and therefore up to 21.5 mtpa.

Ravensthorpe Nickel Operation is a hydrometallurgical processing plant that uses proven technology to recover nickel and cobalt to produce a mixed nickel cobalt hydroxide intermediate product.

Operations involve the open pit mining and beneficiation of nickel laterite ore, pressure acid leaching (“PAL”), atmospheric leaching (“AL”), counter current decantation (“CCD”), precipitation and filtration to produce a Mixed Hydroxide Precipitate (“MHP”) product, containing approximately 40% nickel and 1.4% cobalt on a dry basis.

Description
Nickel and cobalt values are enriched in the fines fractions of both the limonite and Saprolite ores, and the beneficiation process consists of rejecting the principally siliceous coarse fractions using conventional wet ore sizing equipment. Typical mass rejections of 60-70% are achieved at a nominal nickel recovery of 60-65%.

Crushed ore to each Beneficiation circuit is recovered from its respective reclaimer stockp ........