XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1355
were then transferred into the sample cells and weighed
again. The weights of the empty cells were subtracted from
the weights of the sample cells containing the biochar to
make sure both biochar samples are 0.2g each. The sam-
ple cells containing the biochar samples were prepared for
vacuum degassing process to purge impurities out of the
samples. After 5 hours of degassing was completed, sample
cells containing both biochar samples were transferred to
the analysis chamber.
Zeta Potential measurements and surface charge of
hemp hurd, biochar before, and after adsorption were
investigated using the Anton Paar SurPASS 3 Electrokinetic
analyzer consisting of adjustable gap cell. In performing
the analysis, the electrolyte circuit and the measuring cell
were rinsed with deionized water and both the conductiv-
ity and pH electrodes were calibrated. A magnetic stirrer
was placed in the glass beaker and filled with 200 ml of
electrolyte solution. Names were assigned to each of the
samples accordingly and the analysis was initiated with the
SurPASS software.
Experimental Design
In this research, full factorial design was used to analyze
the interaction of the variables that control the intensifi-
cation of rare earth elements adsorption from aqueous
solutions. The experimental design was carried out using
Stat-Ease Design-Expert 13 software based on (2k) full fac-
torial where k represents three factors, i.e., biochar mass
(mg), mixing intensity (G)%, and mixing time (minutes),
respectively. The experimental design is a two-level, three-
factors method of full factorial design. The minimum and
maximum range of values for the three factors, number of
experimental runs, with low and high levels are shown in
the Tables 1 and 2.
Figure 4. Biochar production process
Table 1. Variables and their ranges of values
Variables
Minimum
Values
Maximum
Values Units
Biochar Mass 5 10 mg
Mixing Intensity 10 70 G%
Mixing time 1 25 mins
were then transferred into the sample cells and weighed
again. The weights of the empty cells were subtracted from
the weights of the sample cells containing the biochar to
make sure both biochar samples are 0.2g each. The sam-
ple cells containing the biochar samples were prepared for
vacuum degassing process to purge impurities out of the
samples. After 5 hours of degassing was completed, sample
cells containing both biochar samples were transferred to
the analysis chamber.
Zeta Potential measurements and surface charge of
hemp hurd, biochar before, and after adsorption were
investigated using the Anton Paar SurPASS 3 Electrokinetic
analyzer consisting of adjustable gap cell. In performing
the analysis, the electrolyte circuit and the measuring cell
were rinsed with deionized water and both the conductiv-
ity and pH electrodes were calibrated. A magnetic stirrer
was placed in the glass beaker and filled with 200 ml of
electrolyte solution. Names were assigned to each of the
samples accordingly and the analysis was initiated with the
SurPASS software.
Experimental Design
In this research, full factorial design was used to analyze
the interaction of the variables that control the intensifi-
cation of rare earth elements adsorption from aqueous
solutions. The experimental design was carried out using
Stat-Ease Design-Expert 13 software based on (2k) full fac-
torial where k represents three factors, i.e., biochar mass
(mg), mixing intensity (G)%, and mixing time (minutes),
respectively. The experimental design is a two-level, three-
factors method of full factorial design. The minimum and
maximum range of values for the three factors, number of
experimental runs, with low and high levels are shown in
the Tables 1 and 2.
Figure 4. Biochar production process
Table 1. Variables and their ranges of values
Variables
Minimum
Values
Maximum
Values Units
Biochar Mass 5 10 mg
Mixing Intensity 10 70 G%
Mixing time 1 25 mins