3422 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
attempted in some studies. In this scenario, the fine wastes
are agglomerated by pelletising or briquetting (Rama
Murthy et al., 2018). Production of Mn ore pellets by using
furnace dust is reported. The use of ferromanganese slag as a
construction material, a filler, fertiliser and cement produc-
tion are also reported (Buruiana et al., 2021, Kaabomeir,
2023). Hydrometallurgical methods have been used to
recover Mn from ferromanganese slags (Baumgartner
and Groot, 2014 Mohanty et al., 1998). Naganoor et al.
(2000) performed roasting of ferromanganese slag at 1200
°C with CaO and CaCO3 followed by leaching with ferric
chloride. Mn recovery was 87% at 5% solid, in a 0.154
M FeCl3 solution and a leaching temperature of 80 °C for
2 hours. Presence of sucrose enhanced leaching kinetics and
efficiency. Sulfuric acid curing and water leaching of ferro-
manganese slag was performed by Kazadi et al. (2016). This
method uses minimum amount of water during leaching
and hence known as water starved leaching or quick leach.
Quick leach method was able to improve the filterability
significantly by limiting silica polymerisation resulting up
to 90% of Mn extraction (Kazadi et al., 2016).
A hydrometallurgical method was used to produce
electrolytic manganese dioxide (EMD) from furnace dust
(Önal et al.,2021). An overall 90% of Mn recovery was
achieved through acid leaching in the presence of dextrin
as a reductant followed by jarosite and hydroxide precipita-
tion and electrowinning. Mendonça de Araujo et al. (2006)
used ferromanganese furnace fines to produce electrolytic
manganese metal (EMM). The fines were added to a digest
liquor recycled from the electrolytic cells. The heavy metals
in the leachate were removed by sulphide precipitation.
The use of Mn containing wastes can contribute to min-
imise the need of mining new ore at least to some extent.
As the demand for manganese is significantly growing with
the increase in use of electric vehicles and electronic equip-
ment which demand rechargeable batteries, it is worth-
while investigating the reuse of Mn containing secondary
resources such as HCFM wastes. Only little published work
is available on this regard. Production of high pure manga-
nese sulfate monohydrate using the Mn Mud waste streams
by a hydrometallurgical route was investigated in this study.
The mud was derived from furnace dust captured in the
venturi scrubber. Laboratory scale tests were performed
at different leaching and leachate purification conditions
to check the feasibility of producing HPMSM using Mn
waste streams supplied by a high carbon ferromanganese
producer in Malaysia. The outcome of HPMSM produc-
tion using Mn Mud derived from furnace dust as the raw
material will be discussed in this paper.
MATERIALS AND METHODS
Characterisation and Leaching
Mn mud waste solid was characterised by X-ray fluores-
cence (XRF) and X-ray diffraction (XRD) techniques.
Acid leaching of mud was performed as follows. A mea-
sured mass of Mud equivalent to 20% solid was placed in
a large Erlenmeyer flask. Required amount of 98% sulfuric
acid was mixed with Perth tap water and added to the flask
which contains Mud. The container size should be adequate
to hold the foams generated during the acid addition. The
mixture was agitated for the desired time either using mag-
netic or overhead mechanical stirring.
Purification of Leach Solution
The pregnant leach solution (PLS) was purified by neutrali-
sation-precipitation process with hydrated lime followed by
solvent extraction. Solvent extraction was performed using
the neutralised PLS with Cyanex 272 extractant. Shaking
was performed for the desired time at desired tempera-
ture either using a magnetic stirrer or an incubated orbital
shaker. Once finished, the phase separation was performed
using a separation funnel and the aqueous sample was col-
lected for analysis. For multiple SX tests, the separated
aqueous phase from the cycle 1 was again mixed with fresh
25% Cyanex solution and the separation was performed
same as above. This was performed for 2–3 cycles until the
Ca and Mg concentrations are acceptably low. Scrubbing
and stripping of the organic phase was performed using
diluted sulfuric acid solutions.
RESULTS AND DISCUSSION
Characterisation
The XRF analysis results of mud sample are shown in
Table 2. The mud consisted of 42% of Mn, 2.8% of Fe,
2.1% of Ca, 1.0% of Mg and 0.75% of Zn.
Quantitative XRD was performed to identify the crys-
talline phases. The amorphous regions were also calcu-
lated but the composition could not be identified by this
Table 2. XRF analysis data of mud
Composition, %
Mn Si Al Fe Ca P S Mg K Pb Zn Sr Na
42 1.5 1.3 2.8 2.1 0.03 0.15 1.0 0.84 0.23 0.75 0.03 0.48
attempted in some studies. In this scenario, the fine wastes
are agglomerated by pelletising or briquetting (Rama
Murthy et al., 2018). Production of Mn ore pellets by using
furnace dust is reported. The use of ferromanganese slag as a
construction material, a filler, fertiliser and cement produc-
tion are also reported (Buruiana et al., 2021, Kaabomeir,
2023). Hydrometallurgical methods have been used to
recover Mn from ferromanganese slags (Baumgartner
and Groot, 2014 Mohanty et al., 1998). Naganoor et al.
(2000) performed roasting of ferromanganese slag at 1200
°C with CaO and CaCO3 followed by leaching with ferric
chloride. Mn recovery was 87% at 5% solid, in a 0.154
M FeCl3 solution and a leaching temperature of 80 °C for
2 hours. Presence of sucrose enhanced leaching kinetics and
efficiency. Sulfuric acid curing and water leaching of ferro-
manganese slag was performed by Kazadi et al. (2016). This
method uses minimum amount of water during leaching
and hence known as water starved leaching or quick leach.
Quick leach method was able to improve the filterability
significantly by limiting silica polymerisation resulting up
to 90% of Mn extraction (Kazadi et al., 2016).
A hydrometallurgical method was used to produce
electrolytic manganese dioxide (EMD) from furnace dust
(Önal et al.,2021). An overall 90% of Mn recovery was
achieved through acid leaching in the presence of dextrin
as a reductant followed by jarosite and hydroxide precipita-
tion and electrowinning. Mendonça de Araujo et al. (2006)
used ferromanganese furnace fines to produce electrolytic
manganese metal (EMM). The fines were added to a digest
liquor recycled from the electrolytic cells. The heavy metals
in the leachate were removed by sulphide precipitation.
The use of Mn containing wastes can contribute to min-
imise the need of mining new ore at least to some extent.
As the demand for manganese is significantly growing with
the increase in use of electric vehicles and electronic equip-
ment which demand rechargeable batteries, it is worth-
while investigating the reuse of Mn containing secondary
resources such as HCFM wastes. Only little published work
is available on this regard. Production of high pure manga-
nese sulfate monohydrate using the Mn Mud waste streams
by a hydrometallurgical route was investigated in this study.
The mud was derived from furnace dust captured in the
venturi scrubber. Laboratory scale tests were performed
at different leaching and leachate purification conditions
to check the feasibility of producing HPMSM using Mn
waste streams supplied by a high carbon ferromanganese
producer in Malaysia. The outcome of HPMSM produc-
tion using Mn Mud derived from furnace dust as the raw
material will be discussed in this paper.
MATERIALS AND METHODS
Characterisation and Leaching
Mn mud waste solid was characterised by X-ray fluores-
cence (XRF) and X-ray diffraction (XRD) techniques.
Acid leaching of mud was performed as follows. A mea-
sured mass of Mud equivalent to 20% solid was placed in
a large Erlenmeyer flask. Required amount of 98% sulfuric
acid was mixed with Perth tap water and added to the flask
which contains Mud. The container size should be adequate
to hold the foams generated during the acid addition. The
mixture was agitated for the desired time either using mag-
netic or overhead mechanical stirring.
Purification of Leach Solution
The pregnant leach solution (PLS) was purified by neutrali-
sation-precipitation process with hydrated lime followed by
solvent extraction. Solvent extraction was performed using
the neutralised PLS with Cyanex 272 extractant. Shaking
was performed for the desired time at desired tempera-
ture either using a magnetic stirrer or an incubated orbital
shaker. Once finished, the phase separation was performed
using a separation funnel and the aqueous sample was col-
lected for analysis. For multiple SX tests, the separated
aqueous phase from the cycle 1 was again mixed with fresh
25% Cyanex solution and the separation was performed
same as above. This was performed for 2–3 cycles until the
Ca and Mg concentrations are acceptably low. Scrubbing
and stripping of the organic phase was performed using
diluted sulfuric acid solutions.
RESULTS AND DISCUSSION
Characterisation
The XRF analysis results of mud sample are shown in
Table 2. The mud consisted of 42% of Mn, 2.8% of Fe,
2.1% of Ca, 1.0% of Mg and 0.75% of Zn.
Quantitative XRD was performed to identify the crys-
talline phases. The amorphous regions were also calcu-
lated but the composition could not be identified by this
Table 2. XRF analysis data of mud
Composition, %
Mn Si Al Fe Ca P S Mg K Pb Zn Sr Na
42 1.5 1.3 2.8 2.1 0.03 0.15 1.0 0.84 0.23 0.75 0.03 0.48