Hi Neil,

During the neutralization steps, soda ash (sodium carbonate) and limestone (calcium carbonate) will release carbon dioxide similar to the classic volcano science project that erupts when vinegar (acetic acid) is mixed with baking soda (sodium bicarbonate). If I recall correctly, the final step of lithium carbonate precipitation involves the addition of carbon dioxide. So, it makes sense to capture CO2 released from earlier in the process and reinject it later, instead of releasing it to the atmosphere and finding a new source.   

On this subject, there is an order of magnitude more magnesium than lithium and this consumes the majority of sulfuric acid and results in excess CO2 emissions. I can't wait to see the DFS to learn how the ore beneficiation might change the relative amount of magnesium that is leached during acidification.

AXP