[DionisioDD]

I need help with this problem, so far i only be capable to calculate de O2 and N2

weights.
A mineral of a process contains contains 90% FeS2 and 10% inerts by weight. This material it is calcined with 25% excess air, according to the reaction:



  FeS2 + 02 ► Fe203 + S02



The solid mixture leaves the calciner with 13% inerts by weight and the rest FeS2 and Fe203



a) Calculate the weight of solids leaving the calciner.



b) Determine the% conversion based on FeS2 •



c) Calculate the Orsat analysis of the gases produced.

[chenbeier]

First write down the correct balanced equation. You get information how many moles pyrit correspon to how many moles iron-III-oxide.
Second You have the information the inert material changes from 10% to 13% this mass is fixed.