0001
-
16
Mar
22
0099
-
13
Abr
22
0197
-
21
Abr
22
0295
-
30
Abr
22
0393
-
08
May
22
0491
-
18
May
22
0589
-
25
May
22
0687
-
01
Jun
22
0785
-
16
Jun
22
0883
-
05
Ago
22
0981
-
14
Ago
22
1079
-
27
Ago
22
1176
-
03
Set
22
1274
-
10
Set
22
1372
-
19
Set
22
1469
-
01
Oct
22
1567
-
09
Oct
22
1665
-
27
Oct
22
1763
-
06
Nov
22
1861
-
18
Nov
22
1959
-
26
Nov
22
2057
-
16
Dic
22
2155
-
26
Dic
22
2253
-
03
Ene
23
2351
-
19
Ene
23
2449
-
28
Ene
23
2547
-
10
Feb
23
2645
-
21
Feb
23
pH
Flow
-
m3/h
0001
-
16
Mar
22
0099
-
13
Abr
22
0197
-
21
Abr
22
0295
-
30
Abr
22
0393
-
08
May
22
0491
-
18
May
22
0589
-
25
May
22
0687
-
01
Jun
22
0785
-
16
Jun
22
0883
-
05
Ago
22
0981
-
14
Ago
22
1079
-
27
Ago
22
1176
-
03
Set
22
1274
-
10
Set
22
1372
-
19
Set
22
1469
-
01
Oct
22
1567
-
09
Oct
22
1665
-
27
Oct
22
1763
-
06
Nov
22
1861
-
18
Nov
22
1959
-
26
Nov
22
2057
-
16
Dic
22
2155
-
26
Dic
22
2253
-
03
Ene
23
2351
-
19
Ene
23
2449
-
28
Ene
23
2547
-
10
Feb
23
2645
-
21
Feb
23
Pressure
-
PSI
XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 637
the performance of the UF decreased. When these same
solutions were mixed up stream of the UF feed tank, nor-
mal operation of the UF was observed.
It was more difficult to maintain adequate perfor-
mance of the UF when there was low concentrations of
Fe (200 mg/L) and high turbidity (20NTU) in the feed
solution. For this feed chemistry, it was assumed that the
suspended solids are mostly inert and the UF membranes
required a higher frequency of washing.
A solution made up of 2% hydrochloric acid was found
to be effective in washing the UF membranes and was nec-
essary to maintain adequate performance of the UF system.
During these acid cleaning procedures, it was observed
that it is necessary to avoid direct contact of the acidic water
with oxygen in order to avoid oxidation and precipitation
of Fe. The cleaning procedure was revised for this reason.
The water normally used for rinsing had a neutral pH and
was switched out for RO permeate water that had a pH
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Feed -Reverse Osmosis
Flow pH
Source: Sebastian Franzsen 2022.
Figure 9. Constant feed flow to Reverse Osmosis, typical pH of 2
0
50
100
150
200
250
Pressure -Reverse Osmosis
Feed Concentrate Permeate
Figure 10. Pressures in the feed, permeate and concentrated streams in the Reverse Osmosis. No
significant peaks were observed
-
16
Mar
22
0099
-
13
Abr
22
0197
-
21
Abr
22
0295
-
30
Abr
22
0393
-
08
May
22
0491
-
18
May
22
0589
-
25
May
22
0687
-
01
Jun
22
0785
-
16
Jun
22
0883
-
05
Ago
22
0981
-
14
Ago
22
1079
-
27
Ago
22
1176
-
03
Set
22
1274
-
10
Set
22
1372
-
19
Set
22
1469
-
01
Oct
22
1567
-
09
Oct
22
1665
-
27
Oct
22
1763
-
06
Nov
22
1861
-
18
Nov
22
1959
-
26
Nov
22
2057
-
16
Dic
22
2155
-
26
Dic
22
2253
-
03
Ene
23
2351
-
19
Ene
23
2449
-
28
Ene
23
2547
-
10
Feb
23
2645
-
21
Feb
23
pH
Flow
-
m3/h
0001
-
16
Mar
22
0099
-
13
Abr
22
0197
-
21
Abr
22
0295
-
30
Abr
22
0393
-
08
May
22
0491
-
18
May
22
0589
-
25
May
22
0687
-
01
Jun
22
0785
-
16
Jun
22
0883
-
05
Ago
22
0981
-
14
Ago
22
1079
-
27
Ago
22
1176
-
03
Set
22
1274
-
10
Set
22
1372
-
19
Set
22
1469
-
01
Oct
22
1567
-
09
Oct
22
1665
-
27
Oct
22
1763
-
06
Nov
22
1861
-
18
Nov
22
1959
-
26
Nov
22
2057
-
16
Dic
22
2155
-
26
Dic
22
2253
-
03
Ene
23
2351
-
19
Ene
23
2449
-
28
Ene
23
2547
-
10
Feb
23
2645
-
21
Feb
23
Pressure
-
PSI
XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 637
the performance of the UF decreased. When these same
solutions were mixed up stream of the UF feed tank, nor-
mal operation of the UF was observed.
It was more difficult to maintain adequate perfor-
mance of the UF when there was low concentrations of
Fe (200 mg/L) and high turbidity (20NTU) in the feed
solution. For this feed chemistry, it was assumed that the
suspended solids are mostly inert and the UF membranes
required a higher frequency of washing.
A solution made up of 2% hydrochloric acid was found
to be effective in washing the UF membranes and was nec-
essary to maintain adequate performance of the UF system.
During these acid cleaning procedures, it was observed
that it is necessary to avoid direct contact of the acidic water
with oxygen in order to avoid oxidation and precipitation
of Fe. The cleaning procedure was revised for this reason.
The water normally used for rinsing had a neutral pH and
was switched out for RO permeate water that had a pH
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Feed -Reverse Osmosis
Flow pH
Source: Sebastian Franzsen 2022.
Figure 9. Constant feed flow to Reverse Osmosis, typical pH of 2
0
50
100
150
200
250
Pressure -Reverse Osmosis
Feed Concentrate Permeate
Figure 10. Pressures in the feed, permeate and concentrated streams in the Reverse Osmosis. No
significant peaks were observed