ConCentration plant Lynas owns the richest known deposit of Rare Earths in the world at Mount Weld, 35km south of Laverton, Western Australia.Lynas Corporation’s Concentration Plant is the first crucial stepin processing Rare Earths.The Concentration Plant is located approximately 2km from the Mount Weld mine,35km south of Laverton, Western Australia. The plant is an essential part of Lynas’commitment to leading the growth of the global Rare Earths industry by creatinga reliable, fully integrated source of supply from mine through to a diverse setof customers.The ore at Mount Weld, the richest known deposit of Rare Earths in the world,is mined by open pit methods, crushed, stockpiled and concentrated by flotationin the Concentration Plant to produce a Rare Earths concentrate for export.Lynas have taken a best practice philosophy when designing the Concentration Plant.The concentrate is placed in two tonne bulker bags and then loaded into seacontainers at site. The containers are trucked to the Western Australian Port ofFremantle. At the port the containers are transferred to ships for sea freight to thePort of Kuantan in Pahang, Malaysia, where it will be further refined at the LynasAdvanced Materials Plant (LAMP) to produce our final products.
GeoloGy MininG and StoCkpilinG The mineralised froth that to a storage tank prior toThe Mount Weld Rare Earths Phase 1 of the mining campaign overflows from the top of the next stage. The pulp isdeposit sits in a two billion year was completed in August 2008. the flotation cell can then be thickened to 50% solids, andold volcanic plug. It is estimated 409,204 tonnes of CZ material collected. Likewise, certain water overflows from the top ofthat approximately 1.8km of assaying an average 18% Total chemicals can be added the thickener and is recovered.the volcanic plug has been Lanthanide Oxide (TLnO) was to the pulp to target the The second stage of dewateringweathered during this time to stockpiled into low, medium non-Rare Earth minerals to is called Pressure Filtrationform a high grade supergene and high grade material. The make them hydrophilic (have where the thickened pulp isRare Earth Oxide (REO) deposit. LI material was also stockpiled an affinity with water) and introduced into a plate andThe highest concentration of and totalled 364,075 tonnes hence be depressed, sinking frame membrane filter press atRare Earths is found in the assaying 12.6% TLnO. to the bottom and reporting high pressure to produce a filterCentral Lanthanide Deposit to tailings. cake containing 17% moisture.(CLD) and is currently an open The reagent regime adopted The filter cake discharged CrUSHinG and GrindinGpit to a depth of 51m. The to treat the Mount Weld from the filter press is loadedMount Weld CLD is the richest The stockpiled Run Of Mine (ROM) material is crushed ore has been developed into two tonne double linedknown Rare Earths deposit in over many years of rigorous bags. The bags are loadedthe world. and screened to produce a particle size distribution of testing. Approximately 70% into sea containers, by roadThe Rare Earths are hosted 100% passing 20mm. The sub of the REO is recovered in the train transported to the Portin secondary Rare Earths 20mm material is fed into the flotation circuit and a flotation of Fremantle and shipped tophosphates that can contain grinding circuit by a front end concentrate of 40% REO is Malaysia for further processingup 60-70% REO. They are loader. The grinding circuit produced. at the LAMP.finely disseminated within consists of a single ball mill The first stage of flotationvarious iron oxides, such as in closed circuit to produce a involves one stage of roughing tailinGS StoraGegoethite and limonite. The target grind size of 38µm. The followed by three stages of The flotation tailings generatedRare Earths phosphates within fine grind is required to allow scavenging. The objective of from the process are storedthe CLD are predominantly separation of the valuable the rougher/scavenger circuit is in a purpose built tailingslight Rare Earths enriched, Rare Earths minerals from to recover as much Rare Earths repository. The tailings settlehowever heavy Rare Earths the non-Rare Earths minerals mineral as possible. The second and consolidate to form amineralisation in the form prior to flotation. stage of flotation is termed beach and the water gravityof churchite does exist cleaning. Depressants are added The Mount Weld Concentrator flows towards a central decantin the Duncan Deposit to the concentrate recovered in is designed to process 121,000 where the supernatant liquorand is currently under the rougher/scavenger circuit to tonnes per annum of ore and can be collected and pumpedmetallurgical investigation. remove tailings entrained in the will produce approximately back to the plant and recycledThe Rare Earths within the CLD 33,000 tonnes per annum froth. This process is designed in the future.from the first mining campaign of concentrate in Phase 1 of to achieve a target concentrate grade of 40% REO. The tailings have a grade ofhave been classified into two the Lynas production plan. 6-8% REO and have a highermain lithologies, CZ and LI. Phase 1 of the plan will see REO head grade than mostThe CZ material is a soft friable approximately 11,000 tonnes dewaterinG and other deposits around thesilt stone that comprises about of separated REO produced BaGGinG world. Future retreatment oftwo thirds of the deposit. The in Malaysia. The final flotation concentrate the tailings may be possible.LI material is harder and more is pumped to a 9m diametercompetent than the CZ, as the tank called a thickener, whereminerals are fused together Flotation the solids settle after thewith iron oxide cement. Flotation is a mineral addition of hydrated lime andAdditionally, the Rare Earths processing technique that flocculent. This causes the solidminerals in the LI are finer involves introducing air into particles to come together andgrained than the CZ material. an agitated pulp, together form floccs that are heavy and with selective chemicals, called settle to the bottom of the collectors, to coat the Rare thickener cone. The thickener Earths mineral surface to make has a slow moving rake in it hydrophobic (water repelling). the bottom, which directs Once hydrophobic the Rare the settled solid bed to an Earths minerals attach underflow cone where the themselves to an air bubble thickened pulp is removed and lift from the pulp. by a peristaltic hose pumpThis brochure is printed on Monza Recycled paper, which is an environmentally responsible paper manufacturedwith 55% recycled fibre. It is sourced from sustainable plantation wood and is elemental chlorine free (ECF).