Spinel ferrite transformation for enhanced upgrading nickel grade in laterite ore of various types

2021 ◽  
Vol 163 ◽  
pp. 106795
Author(s):  
Jian-ming Gao ◽  
Wenjie Li ◽  
Shujia Ma ◽  
Zongyuan Du ◽  
Fangqin Cheng
Keyword(s):  
Spinel Ferrite ◽  
Ferrite Transformation ◽  
Nickel Grade ◽  
Laterite Ore

scholarly journals Sulfides Formation in Carbothermic Reduction of Saprolitic Nickel Laterite Ore Using Low-Rank Coals and Additives: A Thermodynamic Simulation Analysis

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 631 ◽  
Author(s):  
Harjanto ◽  
Rhamdhani
Keyword(s):  
Carbothermic Reduction ◽  
Simulation Analysis ◽  
Thermodynamic Simulation ◽  
Low Rank ◽  
Nickel Laterite ◽  
Metals Recovery ◽  
Nickel Laterite Ore ◽  
Nickel Grade ◽  
Low Rank Coals ◽  
Laterite Ore

In this paper, a systematic thermodynamic analysis of carbothermic reduction of saprolitic nickel laterite ore was carried out. Different carbon sources—such as pure C, sub-bituminous, and lignite—were used for the carbothermic reduction at 1000 °C (1273 K). The effect of the different additives—such as S, FeS, Na2S, Na2SO4, and CaSO4—was also systematically evaluated. The thermodynamic calculations suggested that the use of low rank coals (sub-bituminous and lignite) do not significantly affect the nickel grade and nickel recovery, but affect the total metals recovery. The presence of S in these C-sources promoted the formation of sulfides. At 1000 °C (1273 K), only a small amount of C-sources (C, sub-bituminous, lignite) are needed to significantly metallize the nickel in the laterite, i.e., between 4–6 wt %. The additives S, FeS, Na2S, Na2SO4, and CaSO4 were predicted to promote the formation of liquid sulfides, and at the same time reduce the formation of the (Fe,Ni) alloy, thus reducing the nickel and total metals recovery. Therefore, consideration is needed to balance the two aspects. The calculations predicted that S, Na2SO4, and CaSO4 additions provided an increase in the nickel grade; while FeS and Na2S reduced the nickel grade.

Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
Cofe2o4 Nanoparticles ◽  
Core Diameter ◽  
The Core ◽  
Shell Particles ◽  
Interface Parameters ◽  
Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

scholarly journals Probing the Effect of Water Recycling on Flotation through Anion Spiking Using a Low-Grade Cu–Ni–PGM Ore: The Effect of NO3−, SO42− and S2O32−

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 340
Author(s):  
Mathew Dzingai ◽  
Malibongwe S. Manono ◽  
Kirsten C. Corin
Keyword(s):  
Water Chemistry ◽  
Froth Flotation ◽  
Water Source ◽  
Threshold Concentration ◽  
Process Water ◽  
Low Grade ◽  
Unit Operations ◽  
Flotation Performance ◽  
Anion Distribution ◽  
Nickel Grade

Water scarcity necessitates the recycling of process water within mineral processing practices. This may however come with its disadvantages for unit operations such as froth flotation as this process is water intensive and sensitive to water chemistry. It is therefore important to monitor the water chemistry of the recycle stream of process water and any other water source to flotation. Monitoring the concentrations of the anions in recycled process water is therefore important to consider as these are speculated to impact flotation performance. Batch flotation tests were conducted using synthetically prepared plant water (3 SPW) with a TDS of 3069 mg/L as the baseline experiment. 3 SPW contained 528 mg/LNO3− and 720 mg/L SO42−, other anions and cations, and no S2O32−. Upon spiking 3 SPW with selected anions, viz, NO3−, SO42− and S2O32−, it was noted that NO3− and SO42− exhibited threshold concentrations while S2O32− did not show a threshold concentration for both copper and nickel grade. Spiking 3 SPW with 352 mg/L more of NO3− to a total 880 mg/L NO3− concentration resulted in the highest copper and nickel grade compared to 3 SPW while increasing the S2O32− from 60 to 78 mg/L increased nickel and copper grade. 720 to 1200 mg/L SO42− and 528 to 880 mg/L NO3− were deemed the concentration boundaries within which lies the threshold concentration above which flotation performance declines with respect to metal grades, while for S2O32− the threshold concentration lies outside the range considered for this study. Anion distribution between the pulp and the froth did not seem to impact the recovery of copper or nickel. Notably, the correlation between the concentrate grades and anion distribution between the froth and the pulp seemed to be ion dependent.

Synthesis and Investigation of Small g-values for Smart Spinel Ferrite Nanoparticles

2021 ◽  
pp. 159334
Author(s):  
Harun Bayrakdar ◽  
Orhan Yalçın ◽  
Songül Özüm ◽  
Uğur Cengiz
Keyword(s):  
Spinel Ferrite ◽  
Ferrite Nanoparticles

Recent advancements of spinel ferrite based binary nanocomposite photocatalysts in wastewater treatment

Chemosphere ◽  
2021 ◽  
Vol 274 ◽  
pp. 129734
Author(s):  
R. Suresh ◽  
Saravanan Rajendran ◽  
P. Senthil Kumar ◽  
Dai-Viet N. Vo ◽  
Lorena Cornejo-Ponce
Keyword(s):  
Wastewater Treatment ◽  
Spinel Ferrite

scholarly journals A Comparative Study of Acicular Ferrite Transformation Behavior between Surface and Interior in a Low C–Mn Steel by HT-LSCM

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 699
Author(s):  
Xiaojin Liu ◽  
Guo Yuan ◽  
Raja. Devesh Kumar Misra ◽  
Guodong Wang
Keyword(s):  
Grain Boundaries ◽  
Cooling Rate ◽  
Acicular Ferrite ◽  
Laser Scanning ◽  
Sample Surface ◽  
Surface Microstructure ◽  
In Situ Observation ◽  
Low Carbon ◽  
Transformation Behavior ◽  
Ferrite Transformation

In this study, the acicular ferrite transformation behavior of a Ti–Ca deoxidized low carbon steel was studied using a high-temperature laser scanning confocal microscopy (HT-LSCM). The in situ observation of the transformation behavior on the sample surface with different cooling rates was achieved by HT-LSCM. The microstructure between the surface and interior of the HT-LSCM sample was compared. The results showed that Ti–Ca oxide particles were effective sites for acicular ferrite (AF) nucleation. The start transformation temperature at grain boundaries and intragranular particles decreased with an increase in cooling rate, but the AF nucleation rate increased and the surface microstructure was more interlocked. The sample surface microstructure obtained at 3 °C/s was dominated by ferrite side plates, while the ferrite nucleating sites transferred from grain boundaries to intragranular particles when the cooling rate was 15 °C/s. Moreover, it was interesting that the microstructure and microhardness of the sample surface and interior were different. The AF dominating microstructure, obtained in the sample interior, was much finer than the sample surface, and the microhardness of the sample surface was much lower than the sample interior. The combined factors led to a coarse size of AF on the sample surface. AF formed at a higher temperature resulted in the coarse size. The available particles for AF nucleation on the sample surface were quite limited, such that hard impingement between AF plates was much weaker than that in the sample interior. In addition, the transformation stress in austenite on the sample surface could be largely released, which contributed to a coarser AF plate size. The coarse grain size, low dislocation concentration and low carbon content led to lower hardness on the sample surface.

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