XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3073
on QEMSCAN ® analysis, are listed in Table 4. Gold in the
flotation feed, estimated using results from the final con-
centrate and tailings, occurs in various forms, including
AuAg alloy and metallic minerals such as sylvanite, cala-
verite, and petzite. The majority of gold is found in fine
particles dispersed within silicate minerals, with sizes close
to 5 microns, making gold deportment resolution less accu-
rate. Gold is recovered in its various forms, especially as
pure gold and fine gold particles, in the final concentrate
of the plant.
The major silver-bearing minerals identified in the
Åkulla Kankberg ore from plant flotation samples, based
on QEMSCAN ® analysis, are listed in Table 5. Silver in
the flotation feed, estimated using results from the final
concentrate and tailings, occurs mainly as AuAg alloy and
telluride minerals such as hessite (Ag2Te). Similar to gold,
the majority of silver is found in fine particles dispersed
within silicate minerals, with sizes close to 5 microns. Silver
is recovered in various forms, including as pure silver and
silver-bearing minerals, in the final concentrate of the plant.
Gold, silver, and tellurium particles were observed
through SME-BSE images, illustrating the complex occur-
rence of metallic minerals in the ore. The metallic particles
are easily contrasted with the silicate matrix, facilitating par-
ticle observation. Therefore, some specimens that appear to
represent this ore would be particles of gold and tellurium
partially exposed in a silicate grain with finely locked and
dispersed particles, representing a significant variety of tel-
lurium minerals formed in conjunction with Ag, Bi, Sb,
Table 3. Modal mineralogy of the flotation feed in wt%
obtained from QEMSCAN® analysis
Phase Distribution (wt %)
Quartz 47.57
Muscovite 20.87
Andalusite 12.48
Chlorite 11.17
Corundum 4.42
Other Silicates 1.40
Rutile 1.05
Others 1.05
Pyrite 0.96
Biotite 0.62
Other Sulphides 0.05
Sphalerite 0.04
Chalcopyrite 0.02
Table 4. Gold Deportment in wt% for Different Flotation Streams
Mineral
Feed Final
Concentrate Final Tail Bulk –20 µm +20 –45 µm +45 µm
Gold 2.20 4.48 6.37 9.46 9.49 2.17
AuAg 34.21 25.76 42.50 42.55 30.88 34.26
Calaverite (AuTe) 1.64 1.12 0.68 3.09 0.80 1.65
Petzite (Ag3AuTe2) 0.63 1.07 1.10 1.15 1.48 0.62
Sylvanite (Au,AgTe
2 )12.15 12.14 5.94 10.89 7.83 12.21
AuSbTe 0.07 0.07 0.00 0.01 0.01 0.07
Au catch all 49.11 55.35 43.41 32.86 49.51 49.02
Note: The ‘catch-all’ category includes minuscule gold particles for which minerals have not been identified
Table 5. Silver Deportment in wt% for Different Flotation Streams
Mineral
Feed Final
Concentrate
Final
Tail Bulk –20 µm +20 –45 µm +45 µm
AuAg 8.38 14.44 12.86 14.97 19.14 14.33
Petzite (AgAuTe) 0.26 1.09 0.70 0.48 1.50 0.79
Sylvanite (AuAgTe) 0.34 1.48 0.42 1.51 2.00 1.73
Sulfosalts 0.07 0.29 0.68 0.24 0.56 0.07
Hessite (Ag
2 Te) 5.55 8.22 6.04 5.11 8.75 5.84
AgSbTe 0.07 0.02 0.09 0.20 0.05 0.00
AgAsTe(CuFe) 0.18 0.59 0.14 0.01 0.60 0.59
Ag catch all 85.15 73.87 79.07 77.48 67.40 76.65
Note: The ‘catch-all’ category includes minuscule silver particles for which minerals have not been identified
on QEMSCAN ® analysis, are listed in Table 4. Gold in the
flotation feed, estimated using results from the final con-
centrate and tailings, occurs in various forms, including
AuAg alloy and metallic minerals such as sylvanite, cala-
verite, and petzite. The majority of gold is found in fine
particles dispersed within silicate minerals, with sizes close
to 5 microns, making gold deportment resolution less accu-
rate. Gold is recovered in its various forms, especially as
pure gold and fine gold particles, in the final concentrate
of the plant.
The major silver-bearing minerals identified in the
Åkulla Kankberg ore from plant flotation samples, based
on QEMSCAN ® analysis, are listed in Table 5. Silver in
the flotation feed, estimated using results from the final
concentrate and tailings, occurs mainly as AuAg alloy and
telluride minerals such as hessite (Ag2Te). Similar to gold,
the majority of silver is found in fine particles dispersed
within silicate minerals, with sizes close to 5 microns. Silver
is recovered in various forms, including as pure silver and
silver-bearing minerals, in the final concentrate of the plant.
Gold, silver, and tellurium particles were observed
through SME-BSE images, illustrating the complex occur-
rence of metallic minerals in the ore. The metallic particles
are easily contrasted with the silicate matrix, facilitating par-
ticle observation. Therefore, some specimens that appear to
represent this ore would be particles of gold and tellurium
partially exposed in a silicate grain with finely locked and
dispersed particles, representing a significant variety of tel-
lurium minerals formed in conjunction with Ag, Bi, Sb,
Table 3. Modal mineralogy of the flotation feed in wt%
obtained from QEMSCAN® analysis
Phase Distribution (wt %)
Quartz 47.57
Muscovite 20.87
Andalusite 12.48
Chlorite 11.17
Corundum 4.42
Other Silicates 1.40
Rutile 1.05
Others 1.05
Pyrite 0.96
Biotite 0.62
Other Sulphides 0.05
Sphalerite 0.04
Chalcopyrite 0.02
Table 4. Gold Deportment in wt% for Different Flotation Streams
Mineral
Feed Final
Concentrate Final Tail Bulk –20 µm +20 –45 µm +45 µm
Gold 2.20 4.48 6.37 9.46 9.49 2.17
AuAg 34.21 25.76 42.50 42.55 30.88 34.26
Calaverite (AuTe) 1.64 1.12 0.68 3.09 0.80 1.65
Petzite (Ag3AuTe2) 0.63 1.07 1.10 1.15 1.48 0.62
Sylvanite (Au,AgTe
2 )12.15 12.14 5.94 10.89 7.83 12.21
AuSbTe 0.07 0.07 0.00 0.01 0.01 0.07
Au catch all 49.11 55.35 43.41 32.86 49.51 49.02
Note: The ‘catch-all’ category includes minuscule gold particles for which minerals have not been identified
Table 5. Silver Deportment in wt% for Different Flotation Streams
Mineral
Feed Final
Concentrate
Final
Tail Bulk –20 µm +20 –45 µm +45 µm
AuAg 8.38 14.44 12.86 14.97 19.14 14.33
Petzite (AgAuTe) 0.26 1.09 0.70 0.48 1.50 0.79
Sylvanite (AuAgTe) 0.34 1.48 0.42 1.51 2.00 1.73
Sulfosalts 0.07 0.29 0.68 0.24 0.56 0.07
Hessite (Ag
2 Te) 5.55 8.22 6.04 5.11 8.75 5.84
AgSbTe 0.07 0.02 0.09 0.20 0.05 0.00
AgAsTe(CuFe) 0.18 0.59 0.14 0.01 0.60 0.59
Ag catch all 85.15 73.87 79.07 77.48 67.40 76.65
Note: The ‘catch-all’ category includes minuscule silver particles for which minerals have not been identified