Why does production of nickel and copper metals from their ores involve sulfur dioxide emissions?

1 Answer
Aug 7, 2018

Answer:

Well, nickel ores, and copper ores are COMMONLY sulfides...

Explanation:

Please bear in mind that I am a non-specialist, however, nickel is commonly encountered as a MIXED sulfide with iron, i.e. #"pentlandite"#, i.e. #(Fe,Ni)_9S_8#. And chalcocite, #Cu_2S#, and chalcopyrite, #CuFeS_2# are common copper ores. And if we roast the ores in the presence of oxygen...

#Cu_2S(g) + 2O_2(g) stackrel(Delta)rarr2CuO(s)+SO_2(g)uarr#

...the copper oxide is produced, which may be reduced to copper metal, and up the flue we get sulfur dioxide.... i.e. the sulfur in the ore is OXIDIZED...

#S^(2-)+2H_2O(l) rarr SO_2(g)+4H^+ +6e^(-)#