scholarly journals A Thermodynamic Study of the Reduction of a Limonitic Laterite Ore by Methane

2018 ◽  
Vol 37 (9-10) ◽  
pp. 909-919
Author(s):  
C. A. Pickles ◽  
W. Anthony
Keyword(s):  
Nickel Oxide ◽  
Carbon Dioxide Emissions ◽  
Ore Deposits ◽  
Reducing Agent ◽  
Thermodynamic Study ◽  
Nickel Recovery ◽  
Sulphide Ore ◽  
Laterite Ores ◽  
Thermodynamic Simulations ◽  
Laterite Ore

AbstractThe recovery of nickel from the oxidic nickeliferous laterite ores is receiving increasing attention due to the difficulty of recovering this metal from the sulphide ore deposits. One possible solution is to selectively reduce the nickel oxide in the ore, which could then be upgraded by, for example, magnetic concentration. In this article, a thermodynamic study was performed on the reduction of a limonitic laterite ore by methane. Methane was selected as the reducing agent as it has a lower environmental impact than carbon due to the reduced carbon dioxide emissions. The effects of temperatures and methane additions on the nickel recovery and nickel grade were investigated. High recoveries of over 95 % were predicted, but the grades were limited to about 2.5 % due to the formation of magnetite. The thermodynamic simulations for reduction by methane were in agreement with the experimental results in the literature for other reducing agents, reflecting the fact that the nickel oxide in the limonitic ore is relatively unstable. Thus, high recoveries could be achieved irrespective of the reducing agent involved.

Experimental Study on Recovery of Nickel from Nickel-Bearing Laterite

2014 ◽  
Vol 881-883 ◽  
pp. 1611-1615
Author(s):  
Xian Hai Li ◽  
Bi Yang Tuo ◽  
Qin Zhang ◽  
Shen Jun Zhang
Keyword(s):  
Nickel Oxide ◽  
Magnetic Separation ◽  
Reduction Temperature ◽  
Experimental Conditions ◽  
Nickel Recovery ◽  
Technology Process ◽  
Research Findings ◽  
Simple Technology ◽  
Effective Result ◽  
Laterite Ore

It is known that to extract nickel from nickel-bearing laterite ore is not an easy job. By reducing roast-magnetic separation, an effective result is achieved in this research in dealing with nickel-bearing laterite ore due to its simple technology process and the high nickel recovery. Nickel-bearing laterite studied in this research is mainly characterized by fine disseminated grain size and easy argillation. Thus, valuable mineral (i.e. nickel oxide) can not be effectively separated from the nickel-bearing laterite ore simply by regular mineral processing technology. To solve the problem, both reducing roast and wet magnetic separation are adopted in the study with the purpose of making up the lack of dynamics so as to reduce the reduction temperature of nickel laterite. Flux catalyst is added to strengthen the reducing reaction of nickel oxide and iron oxide. The optimistic experimental conditions are determined as following: the consumption of the flux catalyst agent and the reducing agent are 5% and 4% (by weight) respectively, the reduction temperature remains at 1200°C, the reduction time is 2h, and the appropriate magnetic field intensity is 240 RA/m. The research findings show that the nickel grade of the concentrate increases from 1.58% to 5.49%, with its recovery reaching above 80 %.

scholarly journals Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen

2017 ◽  
Vol 36 (8) ◽  
pp. 835-846 ◽  
Author(s):  
R. Elliott ◽  
C. A. Pickles
Keyword(s):  
Froth Flotation ◽  
Selective Reduction ◽  
Metallic Nickel ◽  
State Reduction ◽  
Nickel Recovery ◽  
Laterite Ores ◽  
Sulphide Ores ◽  
Solid State Reduction ◽  
Processing Techniques ◽  
Laterite Ore

AbstractNickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673–873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

Sulphide ore deposits

Nature ◽  
1979 ◽  
Vol 277 (5697) ◽  
pp. 513-514 ◽  
Author(s):  
J. P. N. Bedham
Keyword(s):  
Ore Deposits ◽  
Sulphide Ore

scholarly journals Impact of Reducing Agent on the Synthesis of Nickel Oxide Nanoparticles by Chemical Precipitation Method

2021 ◽  
Vol 10 (1) ◽  
pp. 14-18
Author(s):  
V.Kayathri V.Kayathri ◽  
K.Kousalya K.Kousalya ◽  
A.Mafeena A.Mafeena ◽  
M.Monisha M.Monisha ◽  
S.Naga Nandhini S.Naga Nandhini ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Chemical Precipitation ◽  
Reducing Agent ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
Oxide Nanoparticles ◽  
Nickel Oxide Nanoparticles

Overcoming the Bacteriostatic Effects of Heavy Metals on A. thiooxidans Direct Bioleaching of Saprolitic Ni Laterite Ores

2015 ◽  
Vol 1130 ◽  
pp. 263-267 ◽  
Author(s):  
Hee Chan Jang ◽  
Marjorie Valix
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Stress ◽  
Lag Phase ◽  
Tolerance Index ◽  
Acid Generation ◽  
Laterite Ores ◽  
Laterite Ore

In this study, the adaptation of A. thiooxidans to heavy metals leached from saprolitic Ni laterite ores was performed by gradual acclimatisation. The bacteria was cultivated in heavy metals (Ni, Co, Fe, Mg, Cr and Mn) with total concentrations of 2400 to 24000 ppm equivalent to total dissolution of 1 to 10% (w/v) pulp densities of the saprolitic Ni laterite ore. Adaptation evolution mapped from its tolerance index was found to be dependent on metal concentration, acid generation, and period of adaptation. Bio-stimulation of cell growth and acid production was promoted by heavy metal stress on the bacteria. Pre-established heavy metal tolerance of the bacteria improved the leaching rate in its early phase; 20% and 7% increase in Ni and Co metal recoveries were observed in using adapted bacteria. However heavy metal tolerance was also achieved by the bacteria during the leaching process, albeit delayed by a lag phase. These results confirm the robust nature and suitability of A. thiooxidans in direct biomining of Ni ores.

Mineral deposits and chalcogen gases

1993 ◽  
Vol 57 (389) ◽  
pp. 599-606 ◽  
Author(s):  
Martin Hale
Keyword(s):  
Ore Deposits ◽  
Anomalous Dispersion ◽  
Mineral Deposits ◽  
Oxidation Reactions ◽  
Sulphide Minerals ◽  
Sulphide Ore ◽  
Dispersion Patterns ◽  
Sulphide Deposits ◽  
High Concentrations ◽  
And Migration

AbstractSulphide minerals and their analogues yield gases as a result of oxidation reactions. Even where sulphide minerals are in contact with mildly reducing groundwaters, S2- ions pass into solution and their dispersion patterns can be detected in soil as acid-released H2S. In more oxidising conditions, the metastable gases COS and CS2 are generated. Anomalous dispersion patterns of COS have been reported in soils above more than ten sulphide ore deposits, many of them concealed beneath transported exotic overburden. High concentrations of CS2 occur in the soils over several of the same deposits and uniquely reflect others. Anomalies of SO2 over sulphide deposits are confined to arid terrains. Certain anomalous dispersion patterns of arsenic and tellurium in soils are attributed to the generation and migration of unspecified gases from the oxidation of arsenide and telluride minerals.

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