UW-Madison researchers have developed a method for producing carbon negative supplementary cementitious materials utilizing a carbon mineralization-based direct air capture process named DDAC-REACT (Distributed Direct Air Capture with Rapid Mineral Carbonation). One version of the method comprises pre-treating a mineral feedstock with an alkaline solution, resulting in a pre-treated feedstock and an alkaline solution comprising dissolved alumina or silica. The pre-treated feedstock has enhanced carbonation reactivity in the subsequent DDAC-REACT process. Another version of the method comprises post-treatment of precipitates yielded from DDAC-REACT with an alkaline solution, resulting in a residue and an alkaline solution comprising dissolved alumina or silica. The alkaline solutions resulted from the pre- and post-treatments can be directly used as supplementary cementitious materials (SCM), or as a sorbent solution for carbon capture.