Petalite deposits

Kenora, Ontario, and Emerald Field Resources Big Mack petalite deposit near Kenora, Canada and the now-closed Tin-Spodumene Belt of Foote and FMC in North Carolina, USA. There are large commercial deposits in China, Russia and Zaire (the latter with limited lithium production), and medium-sized ones in Brazil, Namibia, Portugal, Finland and Afghanistan (the latter two not yet mined in 2002 Sailer and O Driscoll, 2000). In the past, and a few at present, of the smaller deposits throughout the world have had limited mining, such as in Rwanda, South Africa and Europe. The major commercial lithium minerals in these deposits are described in the following section. 

The most important mineral for the industrial extraction of lithium is spodumene (LiAlSi206), which is found together with lepidolite, petalite and amblygonite (all with Li contents of 4 to 7%) and in salt lakes. The largest known reserves are in Chile (largest known deposit), Australia, USA and Canada. The main producer countries are the USA (North Carolina), Chile, Australia, Russia, Zimbabwe, Brazil and China. The worldwide reserves including the lithium content in salt lakes is estimated to be 7.3 10 t (as lithium), of which 60% is in salt lakes. 

Large deposits of spodumene have been found in Manono in the Democratic Republic of Congo and of petalite and lepidoHte in Bikita in Zimbabwe. Investigations of pegmatite deposits in Greenbushes, Western Australia, have also revealed large reserves of spodumene. 

At least the petalite conversion aspect of this data appears to be confirmed in some deposits, since after the entire pegmatite was solidified much of the petalite appeared to have been transformed into spodumene and quartz, and occasionally some eucryptite and quartz. The spodumene was in the form of psuedomorphs after petalite, and its very low iron content was similar to that of petalite, and much lower than that of most primary spodumene. However, this phase data and these reactions do not appear to have general applicability, since (1) solid phase reactions do not occur without the solid being remelted or dissolved, at least on a molecular scale, and then recrystallized after the reaction has taken place. (2) The data shows 3-spodumene being stable at 680°C, whereas at atmospheric pressure the change in form from a to 3-spodumene only occurs in ore concentrates above about 1000°C. Also, P-spodumene has never been found in a lithium deposit, and a-spodumene s melting point is shown as 700°C compared to its atmospheric value of 1423°C. (3) Changes in pressure normally have only a relatively minor effect upon a solid s... 

Petalite from the Big Whopper deposit. Separation Rapids, Ontario, Canada (Pearse and Taylor, 2001). 

The Bikita sector has dimensions of about 427 X 29 and 64 m deep, and lepidolite was originally its dominant lithium mineral (most of it has now been mined), but there were also major amounts of spodumene, petalite and amblygonite. The lepidolite was associated with quartz (but no feldspar) in three distinct zones (1) A lepidolite-quartz shell on the upper side and the ends of the deposit with about... 

In Manitoba the East Braintree-West Hawk, Gods Lake, Herb Lake and Cat Lake-Winnipeg River (see Tanco) areas all contain lithium pegmatites. Spodumene is the principal lithium mineral, with some petalite, lepidolite and amblygonite. The small Buck and Pegh lithium deposits were also found in the latter area (Cemy and Lenton, 1995). In 1958 the lithium ore reserves were about 8 million tons in the... 

In the early lithium operations prior to 1960 a 610 m adit was used to enter underground workings in the lepidolite deposit at the 61 m level. Cars were loaded through overhead chutes, and then hauled by diesel locomotives to the beneficiation plant 450 m from the adit. The ore was crushed to about a — 76 mm size and screened, the waste removed by hand sorting from a conveyor belt, and the waste and fines stockpiled for potential future use. The concentrates were often of almost mineral collector s appearance, and they were trucked to the port at Beira for overseas shipment, and later delivered by the Rhodesian Railways. Petalite was mined in an open pit, and also hand sorted, but amblygonite was only obtained by selective hand mining in outcrop areas (Kesler, 1960). 

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