The Pilgangoora pegmatite deposit is one of the largest hard rock lithium deposits in the world. The prospective Pilgangoora pegmatites are located within the East Strelley greenstone belt, approximately 30km east of Wodgina. The pegmatites strike is subparallel to the dominant north-northwest trending fabric of the greenstone belt (Figure 2). The mineralisation at Pilgangoora is hosted within a fractionated pegmatite suite comprising a network of interconnected sheets and easterly dipping dykes.

Two principal pegmatite groups have been identified in the centre of the Pilgangoora Project area: Central and Eastern. Pegmatites within these domains have strike lengths of up to 1.4km and range in thickness to over 70m. Three outlying pegmatite groups including Lynas Find, Monster and Southern are also located within the project area.

In comparison to established classical models of mineralogical zonation around a quartz core, the Pilgangoora pegmatites are quasi-homogenous, characterised by anisotropic mineral assemblages including very coarse or mega-crystic spodumene, elongated sub-perpendicular to the wall rock contacts, aplitic layering and the development of narrow, locally distinct border units. The spodumene-bearing units comprise more than 85% of the volume of the Pilgangoora pegmatite dykes.

The mining method is based on conventional open pit mining, and was evaluated for truck and hydraulic excavator (backhoe) operations utilising 4 x 2.5m flitches for 10m benches for combination waste pegmatite mining and 10m bench mining for waste mining.

Mining operations commenced in December 2017 with the development of the Central pit to support the Stage 1 development and at the Monster pit for the DSO (direct shipping ore) operation. Waste from the Central pit was used in the development of infrastructure including the tailings management facility, run-of-mine (ROM) ore pad and haul road construction.

The concentrator has six key areas including; crushing, feed preparation, dense media separation, gravity separation, grinding, flotation, magnetic separation and dewatering. Wet magnetic separation has been included in the flotation process for the reduction of iron in both the chemical and the future technical grade product.

"During FY20, Pilbara Minerals completed several plant improvement works to enhance operational performance, particularly in respect of lithia recovery. This included works to aid iron removal, improve float performance and rectification of prior works completed by the EPC contractor.

The classification process for ore sizing (grind size) pre-flotation is an important contributor to float performance and overall fines spodumene recovery. Processing plant feed grind size is controlled within relatively tight parameters to maximise performance. To improve grind size control, improvement works were completed in respect of processing ........