3364 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
spodumene flotation has not progressed. He describes the
conventional route and Nemaska, Neometals and FMC
membrane processes. The statement is made that Lepidico
and Lithium Australia use much the same process route and
use fluoride ions to enhance leaching.
SPECIFIC METAL RECOVERIES
For lithium the standard flowsheet is to crush the ore fol-
lowed by DMS and flotation using fatty acids as collec-
tor plus soda ash for pH control and sodium silicate as a
dispersant to produce lithium concentrates. Slimes and
mica removal ahead of DMS and flotation is mandatory.
Designer collectors (fatty acid blends) have been developed
to optimize lithium recovery based on oleic acid/paraffin
soap/tall oil/napthenic acid mixtures. Flotation reagent
vendors provide these reagents optimized for the particu-
lar ore. These concentrates can be sold or converted into
lithium hydroxide or carbonate. The technical challenge is
that battery grade specification requires 99.99% purity.
For tin and tantalum these are recovered as by prod-
ucts using gravity in the beneficiation circuit. Separation
of the tin can be applied and these are sold as concentrates.
Recoveries can be as low as 50%. Flotation can be applied
but is not always economic because of the reagent cost and
recovery is no better than using gravity alone.
For tin, collectors such as carboxylic acid, sulfosuccina-
mates, phosphonic acid derivatives and arsenic acid deriva-
tives are used. Sodium silico fluoride is used as a gangue
depressant. Sodium silicate is used as a dispersant and sul-
furic acid for pH adjustment. Caustic soda is useful in the
cleaning stage. Floating tin slimes is difficult.
For tantalum-niobium, sodium isooctyl phosphate
50–100 g/t at pH 3 or sodium oleate at pH 2.5 provided
good recoveries of +90%. This is based on Canadian expe-
rienced reported by Davies, (1958).
For beryllium, flotation recovery can be in acid or alka-
line circuits. In the acid route the ore is adjusted with HCl,
HF or sulfuric acid and floated with an amine collector. For
alkaline flotation the pulp is conditioned with caustic soda
and the beryl floated using an anionic collector such as fatty
acid. Reverse flotation is also used to separate beryl from
spodumene. It is difficult to achieve a high-grade beryllium
concentrate from low grade feeds.
It has been shown that beryl and spodumene float well
with sulfonate collectors at pH 2.5–4.5 and separation of
the beryllium was achieved using fluoride ions to depress
spodumene from a mixed concentrate. Spodumene can be
activated and floated from the tailings with the help of fer-
ric ions. Using a sulfonate collector (Bhappu &Ferstenau,
1964). Testwork by tabling and flotation of beryl ore
describes beneficiation results of up to 77.8% recovery of
Figure 8. Jiangsu Lithium Carbonate Plant China (METSLibrary)
spodumene flotation has not progressed. He describes the
conventional route and Nemaska, Neometals and FMC
membrane processes. The statement is made that Lepidico
and Lithium Australia use much the same process route and
use fluoride ions to enhance leaching.
SPECIFIC METAL RECOVERIES
For lithium the standard flowsheet is to crush the ore fol-
lowed by DMS and flotation using fatty acids as collec-
tor plus soda ash for pH control and sodium silicate as a
dispersant to produce lithium concentrates. Slimes and
mica removal ahead of DMS and flotation is mandatory.
Designer collectors (fatty acid blends) have been developed
to optimize lithium recovery based on oleic acid/paraffin
soap/tall oil/napthenic acid mixtures. Flotation reagent
vendors provide these reagents optimized for the particu-
lar ore. These concentrates can be sold or converted into
lithium hydroxide or carbonate. The technical challenge is
that battery grade specification requires 99.99% purity.
For tin and tantalum these are recovered as by prod-
ucts using gravity in the beneficiation circuit. Separation
of the tin can be applied and these are sold as concentrates.
Recoveries can be as low as 50%. Flotation can be applied
but is not always economic because of the reagent cost and
recovery is no better than using gravity alone.
For tin, collectors such as carboxylic acid, sulfosuccina-
mates, phosphonic acid derivatives and arsenic acid deriva-
tives are used. Sodium silico fluoride is used as a gangue
depressant. Sodium silicate is used as a dispersant and sul-
furic acid for pH adjustment. Caustic soda is useful in the
cleaning stage. Floating tin slimes is difficult.
For tantalum-niobium, sodium isooctyl phosphate
50–100 g/t at pH 3 or sodium oleate at pH 2.5 provided
good recoveries of +90%. This is based on Canadian expe-
rienced reported by Davies, (1958).
For beryllium, flotation recovery can be in acid or alka-
line circuits. In the acid route the ore is adjusted with HCl,
HF or sulfuric acid and floated with an amine collector. For
alkaline flotation the pulp is conditioned with caustic soda
and the beryl floated using an anionic collector such as fatty
acid. Reverse flotation is also used to separate beryl from
spodumene. It is difficult to achieve a high-grade beryllium
concentrate from low grade feeds.
It has been shown that beryl and spodumene float well
with sulfonate collectors at pH 2.5–4.5 and separation of
the beryllium was achieved using fluoride ions to depress
spodumene from a mixed concentrate. Spodumene can be
activated and floated from the tailings with the help of fer-
ric ions. Using a sulfonate collector (Bhappu &Ferstenau,
1964). Testwork by tabling and flotation of beryl ore
describes beneficiation results of up to 77.8% recovery of
Figure 8. Jiangsu Lithium Carbonate Plant China (METSLibrary)