[pfdietz]

> This article isn't very clear on the fact that CO2 can be re-injected back into the cement later in the production stage.

How can that work? The calcium oxide (or hydroxide) reacts with silica to make silicates, which bind things together. That CaO which reacted is not available to soak up CO2.

[Fyrezerk]

In this particular case the CO2 mineralization is taking place in a wastewater slurry that comes from washing out cement trucks. The carbonated slurry is then re-used as an additive by cement manufacturers.