462 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Typically, the ejected rocks displayed a higher proportion
of yellow pixels, indicative of higher-density materials. In
contrast, unejected rocks were more frequently character-
ized by a predominance of blue pixels, suggesting lower-
density materials. However, it is important to note that the
differences in relative density, as indicated by the DE-XRT
analysis, were quite minimal. This was particularly evi-
dent in the dynamic test using the –4.0/+3.0 size fraction,
where the density contrast was less pronounced than in the
–3.0/+1.5 and –1.5/+0.5 size fractions. As a result, subse-
quent production tests on the REE ore focused exclusively
on the latter two size fractions.
Production Tests with DE-XRT on –3.0/+1.5 and
–1.5/+0.5 Size Fractions of the REE Ore Sample
The production tests on –3.0/+1.5 and –1.5/+0.5 size
fractions of the REE ore sample were performed with the
conditions and parameters listed in Table 8 using the pro-
cessing schemes shown in Figure 11. Metallurgical balances
of these production tests are presented in Table 9. Only
the following components were included in the metal-
lurgical balances: six REEs with significance abundance
variations (La, Ce, Pr, Nd, Sm, Gd) total concentra-
tion of REEs quantified as (REE)(PO4) fluorite (FLU)
Mn-carbonate (MNC) and FeC, MgC and CaC as weight
fractions of Fe, Mg and Ca in the sum of the carbonate
minerals (SID+ANK+DOL SID =siderite, ANK =anker-
ite DOL=dolomite).
In Table 9, the feed grades for the REE(PO4) compo-
nent in the –3.0/+1.5 and –1.5/+0.5 production tests were
calculated to be 1.7 wt% and 1.8 wt%, respectively. In
comparison, the first sorting products (Prod. 1) from these
tests showed increased concentrations of 2.3 wt% for the
–3.0/+1.5 fraction and 2.2 wt% for the –1.5/+0.5 fraction.
These concentrations correspond to upgrading ratios of 1.3
and 1.2, achieved with 4.0% and 10.1% of the initial feed
mass for each size fraction, respectively.
Cumulative recovery vs. mass pull curves obtained in
the production tests with both size fractions are presented
in Figure 12. In general, for a given element or mineral
component, greater preconcentration or prerejection were
achieved in the production test with the –3.0/+1.5 size frac-
tion than in that with –1.5/+0.5 feed material.
In the production tests involving the two size fractions
tested, the six REEs that showed significant abundance
variations demonstrated varied preconcentration levels.
As illustrated in Figure 12, lanthanum (La), Cerium (Ce),
and Praseodymium (Pr) exhibited greater preconcentra-
tion compared to Neodymium (Nd), Samarium (Sm), and
Gadolinium (Gd). For Yttrium (Y), a consistent concen-
tration of approximately 0.03 wt% was observed across
all sorting products. In contrast, concentrations of other
Table 7. Ore sorter conditions and parameters used for dynamic tests with the REE ore sample
Test ID Feed Material
DE-XRT
RD %Area
E9 ~20−25 kg of –4.0/+3.0 rocks 100−230 40−100
E10 ~20−25 kg of –3.0/+1.5 rocks 100−230 40−100
E11 ~20−25 kg of –1.5/+0.5 rocks 150−230 50−100
*RD parameter as defined in Table 1. † %area parameter of the DE-XRT sensor as defined in
Table 1.
Table 8. Ore sorter conditions and parameters of production tests with –3.0/+1.5 and –1.5/+0.5
size fractions of the REE ore sample
Production Test –3.0/+1.5 Production Test –1.5/+0.5
Separation
Run No.
DE-XRT Separation
Run No.
DE-XRT
RD* %area† RD* %area†
1 150−230 50−100 1 150−230 50−100
2 140−230 50−100 2 150−230 40−100
3 130−230 40−100 3 140−230 40−100
4 120−230 40−100 4 130−230 40−100
5 110−230 40−100 5 120−230 40−100
6 100−230 40−100
*RD parameter as defined in Table 1. † %area parameter of the DE-XRT sensor as defined in
Table 1.
Typically, the ejected rocks displayed a higher proportion
of yellow pixels, indicative of higher-density materials. In
contrast, unejected rocks were more frequently character-
ized by a predominance of blue pixels, suggesting lower-
density materials. However, it is important to note that the
differences in relative density, as indicated by the DE-XRT
analysis, were quite minimal. This was particularly evi-
dent in the dynamic test using the –4.0/+3.0 size fraction,
where the density contrast was less pronounced than in the
–3.0/+1.5 and –1.5/+0.5 size fractions. As a result, subse-
quent production tests on the REE ore focused exclusively
on the latter two size fractions.
Production Tests with DE-XRT on –3.0/+1.5 and
–1.5/+0.5 Size Fractions of the REE Ore Sample
The production tests on –3.0/+1.5 and –1.5/+0.5 size
fractions of the REE ore sample were performed with the
conditions and parameters listed in Table 8 using the pro-
cessing schemes shown in Figure 11. Metallurgical balances
of these production tests are presented in Table 9. Only
the following components were included in the metal-
lurgical balances: six REEs with significance abundance
variations (La, Ce, Pr, Nd, Sm, Gd) total concentra-
tion of REEs quantified as (REE)(PO4) fluorite (FLU)
Mn-carbonate (MNC) and FeC, MgC and CaC as weight
fractions of Fe, Mg and Ca in the sum of the carbonate
minerals (SID+ANK+DOL SID =siderite, ANK =anker-
ite DOL=dolomite).
In Table 9, the feed grades for the REE(PO4) compo-
nent in the –3.0/+1.5 and –1.5/+0.5 production tests were
calculated to be 1.7 wt% and 1.8 wt%, respectively. In
comparison, the first sorting products (Prod. 1) from these
tests showed increased concentrations of 2.3 wt% for the
–3.0/+1.5 fraction and 2.2 wt% for the –1.5/+0.5 fraction.
These concentrations correspond to upgrading ratios of 1.3
and 1.2, achieved with 4.0% and 10.1% of the initial feed
mass for each size fraction, respectively.
Cumulative recovery vs. mass pull curves obtained in
the production tests with both size fractions are presented
in Figure 12. In general, for a given element or mineral
component, greater preconcentration or prerejection were
achieved in the production test with the –3.0/+1.5 size frac-
tion than in that with –1.5/+0.5 feed material.
In the production tests involving the two size fractions
tested, the six REEs that showed significant abundance
variations demonstrated varied preconcentration levels.
As illustrated in Figure 12, lanthanum (La), Cerium (Ce),
and Praseodymium (Pr) exhibited greater preconcentra-
tion compared to Neodymium (Nd), Samarium (Sm), and
Gadolinium (Gd). For Yttrium (Y), a consistent concen-
tration of approximately 0.03 wt% was observed across
all sorting products. In contrast, concentrations of other
Table 7. Ore sorter conditions and parameters used for dynamic tests with the REE ore sample
Test ID Feed Material
DE-XRT
RD %Area
E9 ~20−25 kg of –4.0/+3.0 rocks 100−230 40−100
E10 ~20−25 kg of –3.0/+1.5 rocks 100−230 40−100
E11 ~20−25 kg of –1.5/+0.5 rocks 150−230 50−100
*RD parameter as defined in Table 1. † %area parameter of the DE-XRT sensor as defined in
Table 1.
Table 8. Ore sorter conditions and parameters of production tests with –3.0/+1.5 and –1.5/+0.5
size fractions of the REE ore sample
Production Test –3.0/+1.5 Production Test –1.5/+0.5
Separation
Run No.
DE-XRT Separation
Run No.
DE-XRT
RD* %area† RD* %area†
1 150−230 50−100 1 150−230 50−100
2 140−230 50−100 2 150−230 40−100
3 130−230 40−100 3 140−230 40−100
4 120−230 40−100 4 130−230 40−100
5 110−230 40−100 5 120−230 40−100
6 100−230 40−100
*RD parameter as defined in Table 1. † %area parameter of the DE-XRT sensor as defined in
Table 1.