XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3359
reliance on visual judgments. An example of a QEMSCAN
result on one lithium pegmatite dyke is shown in Figure 2.
GEOMETALLURGY AND HARD ROCK
PROCESSING
This is very important when processing pegmatite dykes.
Inductively coupled plasma spectroscopy (ICP) elemen-
tal scans are not enough to classify the ore, as the grain
size (fine and coarse spodumene) plus mineral assemblage
is important and the mineralogy with respect to valuable
minerals present.
Green and purple spodumene can be differentiated by
the ratio of Ta2O5 to Ta2O5+Nb2O5. A ratio of approxi-
mately 0.5 divides these two spodumene types. Below this,
green spodumene is prevalent whilst above is grey/purple
spodumene. Sodium assays provide a direct proxy for
aplite. This is a lesson the early Western Australian opera-
tions had to learn by experience. You cannot blend differ-
ent ore types but in some cases campaign ore domains for
optimum recovery.
The Chinese have a history of processing LPPO depos-
its but very little is recorded apart from a paper describing
this by Siyang and others, 2023, MDPI. Also, Chinese ben-
eficiation of Yifeng Lion low grade ore is described (Meng,
2018) using high grade magnetic separation (HGMS) to
pre concentrate Ta-Nb-Sn concentrates and achieve good
grades with 44.7, 9.13 and 14.6% recovery respectively.
Russian work describes testwork on spodumene tail-
ings using magnetic separation, flotation and gravity to
produce lithium concentrates (Yusupov, 2018).
A review of hard rock beneficiation is described by
Gibson and others, 2017, based on Canadian experience
with lithium.
The Big Whopper complex pegmatite deposit testing
and development in Canada is described as a pegmatite
containing petalite, albite, feldspar, lepidolite, tantalum
minerals and by product micas (Pearse, 2017).
Beneficiation of tantalum and niobium from Wyoming
pegmatites describes gravity and magnetic separation to
produce concentrates from pegmatites (Wouden, 1991).
HIGH PRESSURE GRINDING ROLLS
(HPGR)
The tertiary crushing is achieved using High Pressure
Grinding Rolls (HPGR) which are similar to roll crush-
ers but have high pressure hydraulic cylinders keeping the
rolls together. The rolls have studs and the tyres are replaced
after a period when they become worn. The feed size is
50 mm and the product size is less than 3 mm. The HPGR
is very suitable for very hard, high wear ore which describes
most pegmatite ore. The purpose of the HPGR is to crush
hard ore to a very fine size not possible using conventional
crushers. The roll facings wear and must be replaced every
say 8,000 hours depending on the abrasiveness of the ore.
Figure 2. QEMSCAN Mineralogy Example (METS library)
reliance on visual judgments. An example of a QEMSCAN
result on one lithium pegmatite dyke is shown in Figure 2.
GEOMETALLURGY AND HARD ROCK
PROCESSING
This is very important when processing pegmatite dykes.
Inductively coupled plasma spectroscopy (ICP) elemen-
tal scans are not enough to classify the ore, as the grain
size (fine and coarse spodumene) plus mineral assemblage
is important and the mineralogy with respect to valuable
minerals present.
Green and purple spodumene can be differentiated by
the ratio of Ta2O5 to Ta2O5+Nb2O5. A ratio of approxi-
mately 0.5 divides these two spodumene types. Below this,
green spodumene is prevalent whilst above is grey/purple
spodumene. Sodium assays provide a direct proxy for
aplite. This is a lesson the early Western Australian opera-
tions had to learn by experience. You cannot blend differ-
ent ore types but in some cases campaign ore domains for
optimum recovery.
The Chinese have a history of processing LPPO depos-
its but very little is recorded apart from a paper describing
this by Siyang and others, 2023, MDPI. Also, Chinese ben-
eficiation of Yifeng Lion low grade ore is described (Meng,
2018) using high grade magnetic separation (HGMS) to
pre concentrate Ta-Nb-Sn concentrates and achieve good
grades with 44.7, 9.13 and 14.6% recovery respectively.
Russian work describes testwork on spodumene tail-
ings using magnetic separation, flotation and gravity to
produce lithium concentrates (Yusupov, 2018).
A review of hard rock beneficiation is described by
Gibson and others, 2017, based on Canadian experience
with lithium.
The Big Whopper complex pegmatite deposit testing
and development in Canada is described as a pegmatite
containing petalite, albite, feldspar, lepidolite, tantalum
minerals and by product micas (Pearse, 2017).
Beneficiation of tantalum and niobium from Wyoming
pegmatites describes gravity and magnetic separation to
produce concentrates from pegmatites (Wouden, 1991).
HIGH PRESSURE GRINDING ROLLS
(HPGR)
The tertiary crushing is achieved using High Pressure
Grinding Rolls (HPGR) which are similar to roll crush-
ers but have high pressure hydraulic cylinders keeping the
rolls together. The rolls have studs and the tyres are replaced
after a period when they become worn. The feed size is
50 mm and the product size is less than 3 mm. The HPGR
is very suitable for very hard, high wear ore which describes
most pegmatite ore. The purpose of the HPGR is to crush
hard ore to a very fine size not possible using conventional
crushers. The roll facings wear and must be replaced every
say 8,000 hours depending on the abrasiveness of the ore.
Figure 2. QEMSCAN Mineralogy Example (METS library)