Mineral Processing

The findings of the PFS defined a 1.2 million tonne per annum (Mtpa) mining and processing operation annually producing, on average for the LoM, 75 000 tpa spodumene and 155 000 tpa petalite concentrates destined for the battery (chemical) and glass/ceramics (technical) markets.

During the last year, the Company has completed 25 dedicated diamond drill holes in order to draw representative samples to complete metallurgical, mineralogical and geometallurgical testwork at Arcadia.  The metallurgical test work undertaken to date includes X Ray Diffraction (“XRD”), Heavy Liquid Separation (“HLS”) test work, Dense Medium Separation (“DMS”) pilot plant test work, spiral concentration and flotation test work.

Work is being completed by two independent metallurgical/process laboratories; FT Geolabs in Johannesburg and Nagrom Laboratories in Perth. Both facilities have significant experience in working in and optimising Lithia and tantalite process streams.

Mineralogical analyses (including petrography) carried out included more than 800 individual XRD analyses that provided a high resolution distribution of spodumene and petalite within the orebodies, information that has had vital inputs into mining and process planning. The results indicate the mineralogy of the lithium mineralisation is coarse grained petalite and fine grained spodumene. HLS results show petalite reporting largely to the floats and spodumene to the sinks and following DMS testwork on these products, results reflected a near total recovery of spodumene and petalite minerals. 

Based on the results of these studies, the Company has designed a concentrator plant to process 1.2 Mtpa of ore feed using conventional DMS and froth flotation technology. The processing plant comprises key areas including, three-stage crushing, grinding, dense media separation, mica-flotation, spodumene flotation, petalite flotation, magnetic separation, concentrate dewatering and drying, and tailings filtering

Three lithium product streams will be produced at Arcadia, all aiming at supplyinglithium hydroxide and carbonate plants that supply feed-stock to the lithium battery manufacturers and the glass/ceramics markets. The following products are:

  • ArcadiaLithium 6.5: Spodumene concentrate – 6.5% Li2O and 0.33% Fe2O3
  • ArcadiaLithium 6.1: Spodumene concentrate – 6.1% Li2O and 0.52% Fe2O3
  • ArcadiaLithium 4.2: Petalite concentrate – 4.2% Li2O and 0.08% Fe2O3

 

ArcadiaLithium 6.5
6.5% Li2O & 0.33% Fe2O3 Spodumene (Float)
ArcadiaLithium 6.1
6.1% Li2O & 0.52% Fe2O3 Spodumene (DMS)
ArcadiaLithium 4.2
4.2% Li2O & 0.08% Fe2O3 Petalite (DMS)

Tantalite concentrate (>25 % Ta2O5) will also be produced to serve the downstream electronics markets. Silica sand and mica products will also be produced as by products and sold to domestic markets in Zimbabwe.

Further metallurgical optimisation and enhancement to improve the metallurgical recoveries and concentrate grades is underway. Historically, recoveries of up to 85 % have been achieved in certain parts of the deposit and further testing is required to ascertain whether this can be extended homogenously across the deposit. Potential deleterious elements have not been observed and the identification and removal of iron as a possible impurity will trigger the necessary control measures.

 

Product

 

Year 1

Year 3

Year 5

Year 15

Avg. LoM

+6 % Li2O Spodumene

tpa

72 000

53 000

53 000

123 000

75 000

+4 % Li2O Petalite

tpa

167 000

155 000

155 000

127 000

155 000

Total LCE

tpa

27 000

23 000

23 000

30 000

26 000

Total Lithium Minerals

tpa

239 000

208 000

208 000

250 000

229 000

+25 % Ta2O5

lb. pa

127 000

136 000

136 000

51 000

88 000

Forecast Sales Volumes at Arcadia over the Life Of Mine

 

Arcadia Process Flowsheet