Passivation of chalcopyrite during oxidative leaching in sulfate media

Hackl, Ralph Peter; Dreisinger, David; Peters, E.; King, J. A.

doi:10.1016/0304-386x(95)00023-a

Cited by 391 publications

(153 citation statements)

References 20 publications

Supporting

Mentioning

128

Contrasting

Unclassified

Order By: Relevance

“…Low dissolution rate of copper from chalcopyrite could be attributed to the formation of passive layers 16 such as elemental sulfur layer [17][18][19] , a copper-rich polysulfide layer 20 and layers consisting of iron salt 21 on the chalcopyrite surface. Elemental sulfur layer formed on the surface of chalcopyrite by the oxidation of ferric ions is extremely low electrical conductivity.…”

Section: Discussionmentioning

confidence: 99%

Galvanic Leaching of Chalcopyrite Using Manganese Oxides in Spent Zinc-Carbon Batteries

Nakazawa

Hareyama

2016

Resources Processing

View full text Add to dashboard Cite

It is well known that galvanic interaction between sulfide minerals and manganese oxides in manganese nodules accelerates the leaching of sulfide minerals. Zinc-carbon batteries contain a moist paste (hereafter, black paste) of manganese oxides and graphite powder as cathode mix. We have investigated the feasibility of galvanic leaching of chalcopyrite using chemical reagent MnO 2 and black paste. Addition of MnO 2 enhanced the leaching of chalcopyrite in sulfuric acid media with pH 1.0 and Mn concentration also increased remarkably. Extraction yields of Cu and Mn were 52% and 23% respectively at a MnO 2 to chalcopyrite mass ratio of 4 in 24 days. In the presence of black paste the kinetics of chalcopyrite leaching was accelerated dramatically and 83% of Cu in the concentrate was extracted in 40 hours. The graphite powder contained in black paste could play an important role in the galvanic leaching of chalcopyrite in the presence of MnO 2 .

show abstract

Section: Discussionmentioning

confidence: 99%

Galvanic Leaching of Chalcopyrite Using Manganese Oxides in Spent Zinc-Carbon Batteries

Nakazawa

Hareyama

2016

Resources Processing

View full text Add to dashboard Cite

show abstract

“…The study by Mwase (2016) also showed that increasing the amount of cyanide concentration in the cyanide-only system had no influence on the amount of Pt leached. (Sasaki et al, 2010;Parker et al, 2003;Klauber et al, 2001;Yuzer et al, 2000;Hackl et al, 1995;Mycroft et al, 1995;Pratt et al, 1994). There are some studies (Arena et al, 2016;Olvera et al, 2015;Yang et al, 2015;Khoshkhoo et al, 2014;Hackl et al, 1995) that have used electrochemistry and XPS to explain specifically the phenomenon of passivation in chalcopyrite leaching, although it is acknowledged that chalcopyrite passivation it is not a similar system to the one explored in this study.…”

Section: Introductionmentioning

confidence: 89%

Characterizing the leaching of sperrylite (PtAs 2 ) in cyanide-based solutions

Mwase

Petersen

2017

Hydrometallurgy

View full text Add to dashboard Cite

The mineral sperrylite (PtAs2), unlike other Pt minerals, has shown to be resistant to cyanide leaching, even at elevated temperatures of 50°C. This has prevented further development of a two-stage heap leaching process, of which the second stage is cyanide leaching for a Platreef ore, due to a considerable portion of the Pt being present as sperrylite.Through a comprehensive set of leaching tests, this study has shown that sperrylite leaches slowly in cyanide due to eventual passivation. The addition of ferricyanide to the cyanide solution results in significantly more Pt being leached (up to 16 times) than with cyanide only under identical process conditions. However, over time passivation occurred in this system also, but can be seemingly be overcome by filtering, rinsing and re-suspending the sperrylite. This was further investigated using a reactor system continuously fed with a ferricyanide-cyanide to leach a fixed bed of sperrylite mineral. Again, gradual passivation of the mineral phase was observed, which was fully reversible following a day of feeding with distilled water. XPS analysis of fresh and leached mineral indicated a depletion of As on the mineral surface, which tallied with an observed preferential leaching of As during leaching, at least initially. As a result, it is postulated that a less cyanide-soluble compound of the form PtAs(X) forms, where x is less than 2. The ease with which the leaching process can be restarted after rinsing the mineral indicates that the adsorption of solution species is the key step in forming a passivating layer. This adsorption is potentially favoured by the gradual surface transformation.Finally, an electrochemical study confirmed that the ferricyanide-cyanide system facilitated an electron transfer reaction at the sperrylite surface with the likely oxidation of As and reduction of the ferricyanide. Gradual passivation of the surface was also observed in this system.

show abstract

“…Li et al [42] provided a review of the effect of oxidants. The slow reaction kinetics of chalcopyrite has been investigated by [39,40,[43][44][45][46][47][48]. Typically, the slow reaction rate is due to the formation of surface product layers and passivation and in general an increase in temperature will increase the rate of reaction.…”

Section: Introductionmentioning

confidence: 99%

Heap Leaching: Modelling and Forecasting Using CFD Technology

McBride

Gebhardt²,

Croft

et al. 2018

Minerals

View full text Add to dashboard Cite

Heap leach operations typically employ some form of modelling and forecasting tools to predict cash flow margins and project viability. However, these vary from simple spreadsheets to phenomenological models, with more complex models not commonly employed as they require the greatest amount of time and effort. Yet, accurate production modelling and forecasting are essential for managing production and potentially critical for successful operation of a complex heap, time and effort spent in setting up modelling tools initially may increase profitability in the long term. A brief overview of various modelling approaches is presented, but this paper focuses on the capabilities of a computational fluid dynamics (CFD) model. Advances in computational capability allow for complex CFD models, coupled with leach kinetic models, to be applied to complex ore bodies. In this paper a comprehensive hydrodynamic CFD model is described and applied to chalcopyrite dissolution under heap operating conditions. The model is parameterized against experimental data and validated against a range of experimental leach tests under different thermal conditions. A three-dimensional 'virtual' heap, under fluctuating meteorological conditions, is simulated. Continuous and intermittent irrigation is investigated, showing copper recovery per unit volume of applied leach solution to be slightly increased for pulse irrigation.

show abstract

Passivation of chalcopyrite during oxidative leaching in sulfate media

Cited by 391 publications

References 20 publications

Galvanic Leaching of Chalcopyrite Using Manganese Oxides in Spent Zinc-Carbon Batteries

Galvanic Leaching of Chalcopyrite Using Manganese Oxides in Spent Zinc-Carbon Batteries

Characterizing the leaching of sperrylite (PtAs 2 ) in cyanide-based solutions

Heap Leaching: Modelling and Forecasting Using CFD Technology

Contact Info

Product

Resources

About