4
recommissioning of Beneficiation Plant 2 in 2025), the
following limits were proposed if filtered tailings mixture
disposal is adopted in the future:
• ≤ 6% ultrafine tailings in the mixture (≤10% passing
10µm) – no restrictions in the filtration process.
• 6% to 7% ultrafine tailings in the mixture (10% to
16% passing 10µm) – moderate restrictions in the
filtration process actions to reduce these restric-
tions would be necessary, such as exploring new filter
cloths, using an undercloth, or developing new filtra-
tion aids.
• 7% to 10% ultrafine tailings in the mixture (10% to
16% passing 10µm) – process restrictions, requiring
investments in additional filters.
The impact of the percentage passing 10µm in the mix-
ture on filtration performance requires further investigation
to establish operational limits, considering this param-
eter as a control variable. Additional variables, such as ore
typology and mineralogy, may also influence these results,
necessitating further tests to define operational ranges for
filtration.
In the experimental fills, the use of a filtration aid
led to a noticeable improvement in the workability of the
material, resulting in more consistent geotechnical com-
paction parameters (e.g., reduced gradients and variabil-
ity). Trafficability tests conducted under high precipitation
conditions also showed a significant improvement in the
movement of equipment. In other words, the filtration
aid helps bring the compaction performance of the 95:05
mixture closer to that observed in flotation tailings disposal
(without the addition of fines). However, further testing is
necessary to gain a deeper understanding of these effects.
CONCLUSION
The addition of Floticor FA 17416 filter aid enabled the
filtration plant to process a mixture with 5% ultrafine tail-
ings under similar conditions to those used for sandy tail-
ings alone.
For this mixture, the average filtration rate and cake
moisture were 2.0 t/h*m2 and 12.8%, respectively.
With 10% ultrafine tailings, the filtration rate decreased
to 1.1 t/h*m2 with the use of filter aids. The 90/10 mixture
was identified as the limit for vacuum disc filter technology.
A strong inverse correlation was observed between fil-
tration rate and the percentage of ultrafine tailings in the
mixture (R2 =0.89).
No significant correlation was found between the ultra-
fine tailings percentage (5–10%) and cake moisture, which
ranged from 11.9% to 13.2%.
A noticeable improvement in both the workability and
trafficability of the materials in the experimental fills was
observed, resulting in field behaviour more like that of tail-
ings without the addition of fines.
REFERENCES
Faustino, L., Bicalho, L., Almeida, P., Silva, W. Filter aids
to improve coarse and ultrafine gold tailings filtration.
In: Tailings 2023, Santiago. Tailings 2023 -Santiago:
Gecamin, 2023.
Costa, N., Bicalho, L., Fernandes, P., Silva, W. Filter aids to
improve iron ore tailings filtration. In: Tailings 2021,
Santiago. Tailings 2023 – Santiago: Gecamin, 2021.
Table 1. Results of filter plant
Tailings
mixtures Filter aid
Filter rate
(t/h/m2)
Cake
moisture
(%)
%passin g
10µm
95/05–
13/04/23
NO 1.5 12.8 7.5
95/05–
28/11/23
YES 2.1 13.2 10.7
94/06–
22/05/24
YES 1.8 12.1 10.6
93/07–
05/12/23
YES 1.8 12.2 16.2
92/08–
19/12/23
YES 1.1 12.0 15.8
90/10–
13/12/23
YES 1.2 12.0 16.2
90/10 -
11/04/24
YES 0.8 12.8 15.2
90/10–
13/06/24
YES 1.1 12.2 2.0
Figure 5. Filter rate as a function of the percentage of slimes
in the mixture tailings
recommissioning of Beneficiation Plant 2 in 2025), the
following limits were proposed if filtered tailings mixture
disposal is adopted in the future:
• ≤ 6% ultrafine tailings in the mixture (≤10% passing
10µm) – no restrictions in the filtration process.
• 6% to 7% ultrafine tailings in the mixture (10% to
16% passing 10µm) – moderate restrictions in the
filtration process actions to reduce these restric-
tions would be necessary, such as exploring new filter
cloths, using an undercloth, or developing new filtra-
tion aids.
• 7% to 10% ultrafine tailings in the mixture (10% to
16% passing 10µm) – process restrictions, requiring
investments in additional filters.
The impact of the percentage passing 10µm in the mix-
ture on filtration performance requires further investigation
to establish operational limits, considering this param-
eter as a control variable. Additional variables, such as ore
typology and mineralogy, may also influence these results,
necessitating further tests to define operational ranges for
filtration.
In the experimental fills, the use of a filtration aid
led to a noticeable improvement in the workability of the
material, resulting in more consistent geotechnical com-
paction parameters (e.g., reduced gradients and variabil-
ity). Trafficability tests conducted under high precipitation
conditions also showed a significant improvement in the
movement of equipment. In other words, the filtration
aid helps bring the compaction performance of the 95:05
mixture closer to that observed in flotation tailings disposal
(without the addition of fines). However, further testing is
necessary to gain a deeper understanding of these effects.
CONCLUSION
The addition of Floticor FA 17416 filter aid enabled the
filtration plant to process a mixture with 5% ultrafine tail-
ings under similar conditions to those used for sandy tail-
ings alone.
For this mixture, the average filtration rate and cake
moisture were 2.0 t/h*m2 and 12.8%, respectively.
With 10% ultrafine tailings, the filtration rate decreased
to 1.1 t/h*m2 with the use of filter aids. The 90/10 mixture
was identified as the limit for vacuum disc filter technology.
A strong inverse correlation was observed between fil-
tration rate and the percentage of ultrafine tailings in the
mixture (R2 =0.89).
No significant correlation was found between the ultra-
fine tailings percentage (5–10%) and cake moisture, which
ranged from 11.9% to 13.2%.
A noticeable improvement in both the workability and
trafficability of the materials in the experimental fills was
observed, resulting in field behaviour more like that of tail-
ings without the addition of fines.
REFERENCES
Faustino, L., Bicalho, L., Almeida, P., Silva, W. Filter aids
to improve coarse and ultrafine gold tailings filtration.
In: Tailings 2023, Santiago. Tailings 2023 -Santiago:
Gecamin, 2023.
Costa, N., Bicalho, L., Fernandes, P., Silva, W. Filter aids to
improve iron ore tailings filtration. In: Tailings 2021,
Santiago. Tailings 2023 – Santiago: Gecamin, 2021.
Table 1. Results of filter plant
Tailings
mixtures Filter aid
Filter rate
(t/h/m2)
Cake
moisture
(%)
%passin g
10µm
95/05–
13/04/23
NO 1.5 12.8 7.5
95/05–
28/11/23
YES 2.1 13.2 10.7
94/06–
22/05/24
YES 1.8 12.1 10.6
93/07–
05/12/23
YES 1.8 12.2 16.2
92/08–
19/12/23
YES 1.1 12.0 15.8
90/10–
13/12/23
YES 1.2 12.0 16.2
90/10 -
11/04/24
YES 0.8 12.8 15.2
90/10–
13/06/24
YES 1.1 12.2 2.0
Figure 5. Filter rate as a function of the percentage of slimes
in the mixture tailings