XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 579
roll-2 with a roll speed of 200 rpm and the magnetic frac-
tion obtained from roll-2 was further treated in roll-3 with a
higher roll speed of 250 rpm. Referring to Figure 11, it can
be observed that a chromite enrichment of 34.89% with
17.54% SiO2 was achieved along with a yield of ~65% and
Cr to Fe ratio 3.07 which was encouraging as compared to
the previous results.
The magnetic fraction of roll-1 obtained in (Exp-1)
with 30.49% Cr2O3 was treated in roll-2 and the non-
magnetic fraction of roll-2 obtained was further treated in
roll-3 with a lower roll speed of 120 rpm. The aim was to
achieve a minimum misplacement in both the cases and
hence splitter position was adjusted accordingly by manual
observation. It can be observed from Figure 10, that a a
chromite enrichment of 34.11% along with 17.91% SiO2
was successfully achieved with a yield of ~70.71% and Cr
to Fe ratio of 2.91.
So, based on the optimization test results, the follow-
ing conclusion can be drawn. Firstly, with only first roll
configuration a chromite enrichment of 31.06% and SiO2
of 19.22% can be achieved with yield of ~86% and Cr to
Fe ratio of 2.42.
secondly, with a three-roll configuration further enrich-
ment of 34.89% Cr2O3 with 17.54% SiO2 was achieved
along with a yield of ~65% and Cr to Fe ratio 3.07.
Comparison with Wet Beneficiation
The results obtained (refer Figure 12) from the dry pro-
cessing method are compared with the wet processing
method. This comparative evaluation was aimed to provide
a comprehensive understanding of the effects of these two
distinct approaches on the final outcomes. The findings
revealed notable disparities shedding light on the distinct
advantages and limitations associated with each processing
technique.
Gravity concentration process was considered, and
beneficiation tests were performed on the wet shaking
table. The obtained results are depicted in the graph below.
It can be observed that with wet beneficiation, SiO2 can
be reduced upto 11.12% and Cr2O3 was upgraded till
41.59% with a yield of 53.78%. It can be observed that the
better reduction in silica was observed in the wet beneficia-
tion which may be attributed to the following two parts.
EX P -1 (R O LL -1 )EX P -1 (R O LL -2 )M A G
C LE A N IN G
EX P -1 (R O LL -3 )N .M A G
C LE A N IN G
Cr2O3 SiO2 Yield
Figure 10. Optimisation test carried out by magnetic cleaning configuration
EX P -7 (R O LL -1 )EX P -7 (R O LL -2 )N .M A G
C LE A N IN G
EX P -7 (R O LL -3 )M A G
C LE A N IN G
Cr2O3% SiO2% Yield(%)
Figure 11. Optimization test carried out by nonmagnetic cleaning configuration
30.49 31.84 34.11 19.61 18.97 17.91
90.3
71.9 70.71
27.78 32.32 34.89 21.53 19.36 17.54
79.3 69.71 65.77
roll-2 with a roll speed of 200 rpm and the magnetic frac-
tion obtained from roll-2 was further treated in roll-3 with a
higher roll speed of 250 rpm. Referring to Figure 11, it can
be observed that a chromite enrichment of 34.89% with
17.54% SiO2 was achieved along with a yield of ~65% and
Cr to Fe ratio 3.07 which was encouraging as compared to
the previous results.
The magnetic fraction of roll-1 obtained in (Exp-1)
with 30.49% Cr2O3 was treated in roll-2 and the non-
magnetic fraction of roll-2 obtained was further treated in
roll-3 with a lower roll speed of 120 rpm. The aim was to
achieve a minimum misplacement in both the cases and
hence splitter position was adjusted accordingly by manual
observation. It can be observed from Figure 10, that a a
chromite enrichment of 34.11% along with 17.91% SiO2
was successfully achieved with a yield of ~70.71% and Cr
to Fe ratio of 2.91.
So, based on the optimization test results, the follow-
ing conclusion can be drawn. Firstly, with only first roll
configuration a chromite enrichment of 31.06% and SiO2
of 19.22% can be achieved with yield of ~86% and Cr to
Fe ratio of 2.42.
secondly, with a three-roll configuration further enrich-
ment of 34.89% Cr2O3 with 17.54% SiO2 was achieved
along with a yield of ~65% and Cr to Fe ratio 3.07.
Comparison with Wet Beneficiation
The results obtained (refer Figure 12) from the dry pro-
cessing method are compared with the wet processing
method. This comparative evaluation was aimed to provide
a comprehensive understanding of the effects of these two
distinct approaches on the final outcomes. The findings
revealed notable disparities shedding light on the distinct
advantages and limitations associated with each processing
technique.
Gravity concentration process was considered, and
beneficiation tests were performed on the wet shaking
table. The obtained results are depicted in the graph below.
It can be observed that with wet beneficiation, SiO2 can
be reduced upto 11.12% and Cr2O3 was upgraded till
41.59% with a yield of 53.78%. It can be observed that the
better reduction in silica was observed in the wet beneficia-
tion which may be attributed to the following two parts.
EX P -1 (R O LL -1 )EX P -1 (R O LL -2 )M A G
C LE A N IN G
EX P -1 (R O LL -3 )N .M A G
C LE A N IN G
Cr2O3 SiO2 Yield
Figure 10. Optimisation test carried out by magnetic cleaning configuration
EX P -7 (R O LL -1 )EX P -7 (R O LL -2 )N .M A G
C LE A N IN G
EX P -7 (R O LL -3 )M A G
C LE A N IN G
Cr2O3% SiO2% Yield(%)
Figure 11. Optimization test carried out by nonmagnetic cleaning configuration
30.49 31.84 34.11 19.61 18.97 17.91
90.3
71.9 70.71
27.78 32.32 34.89 21.53 19.36 17.54
79.3 69.71 65.77