XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1253
the rapid adsorption in the initial stages. SW showed a sim-
ilar adsorption capacity to WCC but significantly dropped
after a high concentration of 640ppm, showing the limited
adsorption capacity of the biochar. Comparatively, AH had
the maximum equilibrium adsorption capacity between the
three biochars, followed by WCC and SW, with adsorption
capacities of 129mg/g, 52mg/g, and 42.0mg/g, respectively.
AH has three times that of SW capacity and a highly sig-
nificant difference compared to WCC. Although REEs are
often found in lower concentrations (ppb levels) in most
aqueous sources, their rapid adsorption on the biochars in
the early stages demonstrates the favorable usability of the
three biochars.
As shown in Figure 9, HNO3 exhibited a significantly
higher desorption rate than HCl and NaOH at any given
concentration. 0.2 M HNO3 resulted in the highest desorp-
tion rate (99%), which is followed by 0.5 M HNO3 (84%)
and 0.01 M HNO3 (67%). Between the HCl and NaOH,
it can be seen from the same figure that HCl has a superior
desorption capability than NaOH. However, it was also
0
20
40
60
80
100
120
0 200 400 600 800 1000 1200
Initial concentration (mg/l)
SW
WCC
AH
Figure 7. Effect of initial elemental concentration on the adsorption capacity at pH 5
0
20
40
60
80
100
0 200 400 600 800 1000 1200
Initial Lanthanum Concentration (mg/l)
SW
WCC
AH
Figure 8. Effect of initial elemental concentration on the adsorption performance at pH 5
Adsorpti
capacit(mg/g)
Uptake
%
the rapid adsorption in the initial stages. SW showed a sim-
ilar adsorption capacity to WCC but significantly dropped
after a high concentration of 640ppm, showing the limited
adsorption capacity of the biochar. Comparatively, AH had
the maximum equilibrium adsorption capacity between the
three biochars, followed by WCC and SW, with adsorption
capacities of 129mg/g, 52mg/g, and 42.0mg/g, respectively.
AH has three times that of SW capacity and a highly sig-
nificant difference compared to WCC. Although REEs are
often found in lower concentrations (ppb levels) in most
aqueous sources, their rapid adsorption on the biochars in
the early stages demonstrates the favorable usability of the
three biochars.
As shown in Figure 9, HNO3 exhibited a significantly
higher desorption rate than HCl and NaOH at any given
concentration. 0.2 M HNO3 resulted in the highest desorp-
tion rate (99%), which is followed by 0.5 M HNO3 (84%)
and 0.01 M HNO3 (67%). Between the HCl and NaOH,
it can be seen from the same figure that HCl has a superior
desorption capability than NaOH. However, it was also
0
20
40
60
80
100
120
0 200 400 600 800 1000 1200
Initial concentration (mg/l)
SW
WCC
AH
Figure 7. Effect of initial elemental concentration on the adsorption capacity at pH 5
0
20
40
60
80
100
0 200 400 600 800 1000 1200
Initial Lanthanum Concentration (mg/l)
SW
WCC
AH
Figure 8. Effect of initial elemental concentration on the adsorption performance at pH 5
Adsorpti
capacit(mg/g)
Uptake
%