XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3345
function, each sample was first measured at 20 K, where
all diffusive motions are essentially frozen in the measured
time scale. Subsequently, the samples were measured at
several higher temperatures ranging from 250 to 600 K
to determine the characteristics of hydrogen diffusion in
these samples. The QENS experimental temperature his-
tory is displayed in Figure 1(a). The sample was initially
heated up to 450K and then cooled down to 20K and an
elastic intensity scan was collected upon cooling with 10K/
step (Scan 1). At 20K, the baseline QENS spectrum was
collected, and subsequent spectra were collected at 250K,
300K, 350K, and 400K. Sequentially, an additional elastic
intensity scan was collected upon heating between 400K
and 550K with 10K/step (Scan 2) and a QENS spectrum
was collected at 550K. A new elastic intensity scan was col-
lected upon heating between 550K and 600K with ~17K/
step (Scan 3). Finally, a QENS spectrum was collected at
600K, and an elastic intensity scan was collected upon
cooling between 600K and 410K with 15K/step (Scan 4).
For Al2O3-LDH, as displayed in Figure 1(b), the sample
was initially heated up to 350K, cooled down to 20K and
an elastic intensity scan was collected upon cooling with
20K/step. At 20K, the baseline QENS spectrum was col-
lected, and subsequent spectra were collected at 300K,
350K, 400K, 450K, 500K, 550K, and 600K. For Fe-LDH,
displayed in Figure 1(c), a baseline QENS spectrum was
collected at 20K, and additional spectra were collected at
400K and 500K.
RESULTS AND DISCUSSION
In our previous work, several discussions have been made
based on X-ray powder diffraction, thermal analyses, and
inelastic neutron scattering (INS) experiments. [Wu 2019,
Wu 2019] We observed that the DSC scan for Al2O3 –
LDH exhibits an endothermic process at 613K (340°C)
due to water elimination, while Al(OH)3 – LDH undergoes
two similar events at 493K and 553K (220 and 280 °C).
With thermal analysis, it was also observed that Al(OH)3 –
LDH allocates the larger content of water in its structure,
followed by Al2O3 – LDH. In all samples, no structural
Figure 1. History of the experiments performed at BASIS with the samples of (a) Al(OH
3 )-LDH, (b) Al
2 O
3 -LDH, and
(c) Fe-LDH
(a) (b)
(c)
function, each sample was first measured at 20 K, where
all diffusive motions are essentially frozen in the measured
time scale. Subsequently, the samples were measured at
several higher temperatures ranging from 250 to 600 K
to determine the characteristics of hydrogen diffusion in
these samples. The QENS experimental temperature his-
tory is displayed in Figure 1(a). The sample was initially
heated up to 450K and then cooled down to 20K and an
elastic intensity scan was collected upon cooling with 10K/
step (Scan 1). At 20K, the baseline QENS spectrum was
collected, and subsequent spectra were collected at 250K,
300K, 350K, and 400K. Sequentially, an additional elastic
intensity scan was collected upon heating between 400K
and 550K with 10K/step (Scan 2) and a QENS spectrum
was collected at 550K. A new elastic intensity scan was col-
lected upon heating between 550K and 600K with ~17K/
step (Scan 3). Finally, a QENS spectrum was collected at
600K, and an elastic intensity scan was collected upon
cooling between 600K and 410K with 15K/step (Scan 4).
For Al2O3-LDH, as displayed in Figure 1(b), the sample
was initially heated up to 350K, cooled down to 20K and
an elastic intensity scan was collected upon cooling with
20K/step. At 20K, the baseline QENS spectrum was col-
lected, and subsequent spectra were collected at 300K,
350K, 400K, 450K, 500K, 550K, and 600K. For Fe-LDH,
displayed in Figure 1(c), a baseline QENS spectrum was
collected at 20K, and additional spectra were collected at
400K and 500K.
RESULTS AND DISCUSSION
In our previous work, several discussions have been made
based on X-ray powder diffraction, thermal analyses, and
inelastic neutron scattering (INS) experiments. [Wu 2019,
Wu 2019] We observed that the DSC scan for Al2O3 –
LDH exhibits an endothermic process at 613K (340°C)
due to water elimination, while Al(OH)3 – LDH undergoes
two similar events at 493K and 553K (220 and 280 °C).
With thermal analysis, it was also observed that Al(OH)3 –
LDH allocates the larger content of water in its structure,
followed by Al2O3 – LDH. In all samples, no structural
Figure 1. History of the experiments performed at BASIS with the samples of (a) Al(OH
3 )-LDH, (b) Al
2 O
3 -LDH, and
(c) Fe-LDH
(a) (b)
(c)