English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The electrochemical oxidation of chalcopyrite (CuFeS 2 ) and its metal-enriched derivatives, haycockite (Cu 4 Fe 5 S 8 ), mooihoekite (Cu 9 Fe 9 S 16 ), and talnakhite (Cu 9 Fe 8 S 16 ), have been investigated using electrochemical techniques and X-ray photoelectron spectroscopy. The results show that when chalcopyrite, haycockite, mooihoekite, and talnakhite are oxidized in 1 M HClO 4  in the electrode potential region of 0.2-0.6 V vs. S.C.E. at 298 K, the oxidation products are Cu x S* z , Fe 2+  and, at electrode potentials &gt; 0.53 V vs. S.C.E., Fe 3+  ions; Cu x S* z  represents a metastable phase at the electrode surface. The relative rates of oxidation are in the order haycockite &gt; mooihoekite &gt; talnakhite &gt; chalcopyrite. After oxidation of Fe surface sites, the rate-determining step apparently involves transport of Fe ions from the bulk to the solid-electrolyte interface. When chalcopyrite, haycockite, mooihoekite, and talnakhite are oxidized in 0.1 M, borax in the electrode potential range of -0.6-0.3 V vs. S.C.E. at 298 K, the primary oxidation products are Cu x S* z  and Fe 2 O 3 . The initial oxidation rates of haycockite, mooihoekite, and talnakhite are higher than chalcopyrite, but this initially more facile oxidation of haycockite, mooihoekite, and talnakhite results in metal oxide (mainly iron oxide) surface films, which retard further oxidation to a greater extent than on chalcopyrite. When chalcopyrite, haycockite, mooihoekite, and talnakhite are oxidized in 0.3 MNaCl + HCl solution of pH 0.1, the oxidation rates remain essentially in the order haycockite &gt; mooihoekite &gt; talnakhite &gt; chalcopyrite. However, probably because chloride ions form complexes with Cu +  ions and may act as a bridge in electron transfer, the oxidation rate is significantly enhanced compared to that in 1 M perchloric acid and 0.1 M borax aqueous solutions.

Electrochemical oxidation of chalcopyrite (CuFeS 2 ) and the related metal-enriched derivatives Cu 4 Fe 5 S 8 , CU 9 Fe 9 S 16 ,and Cu 9 Fe 8 S 16