scholarly journals Iron Control in Atmospheric Acid Laterite Leaching

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 404 ◽  
Author(s):  
Ville Miettinen ◽  
Jarno Mäkinen ◽  
Eero Kolehmainen ◽  
Tero Kravtsov ◽  
Lotta Rintala
Keyword(s):  
Acid Leaching ◽  
Precipitation Process ◽  
Precipitation Reaction ◽  
Leaching Tests ◽  
Nickel Laterite ◽  
Iron Dissolution ◽  
Iron Precipitation ◽  
Acid Consumption ◽  
Nickel Leaching

Iron control in the atmospheric acid leaching (AL) of nickel laterite was evaluated in this study. The aim was to decrease acid consumption and iron dissolution by iron precipitation during nickel leaching. The combined acid leaching and iron precipitation process involves direct acid leaching of the limonite type of laterite followed by a simultaneous iron precipitation and nickel leaching step. Iron precipitation as jarosite is carried out by using nickel containing silicate laterite for neutralization. Acid is generated in the jarosite precipitation reaction, and it dissolves nickel and other metals like magnesium from the silicate laterite. Leaching tests were carried out using three laterite samples from the Agios Ioannis, Evia Island, and Kastoria mines in Greece. Relatively low acid consumption was achieved during the combined precipitation and acid leaching tests. The acid consumption was approximately 0.4 kg acid per kg laterite, whereas the acid consumption in direct acid leaching of the same laterite samples was approximately 0.6–0.8 kg acid per kg laterite. Iron dissolution was only 1.5–3% during the combined precipitation and acid leaching tests, whereas in direct acid leaching it was 15–30% with the Agios Ioannis and Evia Island samples and 80% with the Kastoria sample.

Atmospheric Acid Leaching of a Ferruginous Nickel Laterite

2013 ◽  
Vol 634-638 ◽  
pp. 3196-3200
Author(s):  
Kui Liu ◽  
Xue Mei Su
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Atmospheric Pressure ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Nickel Laterite ◽  
Nickel Extraction ◽  
Solid Ratio ◽  
Acid Consumption ◽  
Two Factors

A ferruginous nickel laterite was leached by sulfuric acid at atmospheric pressure. Nickel extraction was largely dependent on sulfuric acid concentration and leaching temperature. Besides these two factors, leaching time and liquid/solid ratio also influenced cobalt extraction significantly. Nickel was easier to be extracted than cobalt. About 95% nickel and cobalt could be extracted when leaching with 5mol/L sulfuric acid for 2h at 100°C, and the acid consumption was 1.417kg H2SO4/kg dry ore.

scholarly journals Copper Extraction from Black Copper Ores through Modification of the Solution Potential in the Irrigation Solution

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1339
Author(s):  
Oscar Benavente ◽  
Ma.Cecilia Hernández ◽  
Evelyn Melo ◽  
Luis Ardiles ◽  
Víctor Quezada ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sulfur Dioxide ◽  
Acid Leaching ◽  
Extraction Rate ◽  
Copper Extraction ◽  
Leaching Tests ◽  
Column Leaching ◽  
White Metal ◽  
Acid Consumption ◽  
Irrigation Solution

This article presented the behavior of ores containing black copper under acid leaching. The solution potential was modified by adding agents, and five leaching conditions were evaluated, one as a control based on sulfuric acid leaching (conventional), and the others by changing the solution potential with: ferrous sulfate (FeSO4), white metal (Cu2S), sulfur dioxide (SO2), and ozone (O3). Leaching behavior was evaluated with laboratory bottle (ISO-pH) and column leaching tests. Two ores samples from the Lomas Bayas mine were used. The samples, identified as low (LG) and high grade (HG), were characterized as 0.13–0.25% Cu and 0.15–0.38% Mn, respectively. The mineralogical analysis indicated that black copper represented around 20% of total Cu (0.05% Cu). The results of the bottle tests indicated that the solution potential decreased with the addition of reducing agents, while the copper extraction rate with the HG sample increased to 83.7%, which exceeded the extraction rate obtained by conventional acid leaching by 25%. Ozone did not favor the extraction of Mn and Cu extraction when the solution potential increased. Cu and Mn extraction were directly related. The results of the column leaching tests showed that it was possible to maintain the solution potential at values below 600 mV (SHE) with the addition of white metal and sulfur dioxide while obtaining the highest copper extraction rate of approximately 60%, which was 18% higher than the rate obtained with conventional leaching. Sulfuric acid consumption was 11 kg/t over 45 days of leaching.

X-ray diffraction line profile analysis of acid-resistant goethite in Western Australian nickel laterite ore

2015 ◽  
Vol 48 (3) ◽  
pp. 814-826
Author(s):  
Xiaodong Wang ◽  
Jian Li ◽  
Robbie G. McDonald ◽  
Arie van Riessen ◽  
Robert D. Hart
Keyword(s):  
Size Distribution ◽  
Size Fraction ◽  
Acid Leaching ◽  
Domain Size ◽  
Line Profile Analysis ◽  
Nickel Laterite ◽  
X Ray ◽  
Peak Broadening ◽  
Nickel Laterite Ore ◽  
Laterite Ore

The goethite peaks in synchrotron and laboratory X-ray powder diffraction (XRPD) patterns of an acid-resistant nickel laterite ore sample from a site in Western Australia exhibit a `super-Lorentzian' shape. The method for extracting the coherently scattering domain size distribution published by Leoni & Scardi [J. Appl. Cryst.(2004),37, 629–634] is adapted to fit the asymmetric goethite peak profiles, allowing the refinement of lattice parameters for multiple goethite structural models while maintaining their relationships. The anisotropic peak broadening due to the acicular shape of the goethite crystals is addressed using spherical harmonics predefined from an XRPD pattern of a synthetic goethite sample. A bimodal coherently scattering domain size distribution of goethite crystals is predicted from the goethite profile fitting and agrees with previous transmission electron microscopy findings that two goethite populations with different domain sizes and metal substitutions exist in the ore sample. The small goethite size fraction dissolved slowly during atmospheric acid leaching, while the large goethite fraction barely dissolved. Caustic pre-treatment by KOH digestion significantly enhanced the acid-leaching performance of the small goethite fraction, but had no effect on the large goethite fraction. This study demonstrates that quantitative phase analysis on designated goethite size fractions can successfully fit the super-Lorentzian shaped line profiles of natural goethite crystals with a confirmed bimodal domain size distribution.

Nickel Loss during Iron Precipitation and Product Characterization

2011 ◽  
Vol 402 ◽  
pp. 293-296
Author(s):  
Kai Wang ◽  
Jian Li ◽  
R.G. McDonald ◽  
R.E. Browner
Keyword(s):  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Precipitation Process ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Iron Precipitation ◽  
Product Characterization ◽  
Ph Range ◽  
Iron Precipitates

In this study, the iron precipitation and associated nickel loss from synthetic ferric and nickel sulphate solutions were investigated. Two types of common neutralizing agents, magnesium oxide and calcium carbonate were applied in the investigation. The results indicated that pH and temperature had significant impacts on nickel loss during the iron precipitation process, whereas the type of neutralizing agents had little effect. It was found that increasing in pH and temperature resulted in more nickel loss in the pH range of 2 to 4 and temperature range of 25 to 85 °C. Mineralogical examination by XRD indicated that the iron precipitates were combinations of schwertmannite, ferrihydrite and goethite. In addition, more crystalline goethite was formed from the ferric solutions when no nickel was present, indicating that nickel might play a role in inhabiting the crystallization of goethite.

Pressure acid leaching of arid-region nickel laterite ore

2003 ◽  
Vol 70 (1-3) ◽  
pp. 31-46 ◽  
Author(s):  
B.I. Whittington ◽  
R.G. McDonald ◽  
J.A. Johnson ◽  
D.M. Muir
Keyword(s):  
Arid Region ◽  
Acid Leaching ◽  
Nickel Laterite ◽  
Nickel Laterite Ore ◽  
Pressure Acid Leaching ◽  
Laterite Ore
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