Quantifying the effect of grain size on weathering of basaltic powders: Implications for negative emission technologies via soil carbon sequestration

Elizabeth Vanderkloot, Peter Ryan Abstract Weathering of basaltic powders was studied experimentally at 35 °C in dilute solutions of oxalic acid and carbonic acid to assess the effect of grain size and reactive surface area for materials under consideration for carbon dioxide reduction (CDR) by enhanced rock weathering (ERW). The basalts chosen for this study (with their mineralogical compositions) are the Blue Ridge (BR) meta-basalt (chlorite > epidote > plagioclase > actinolite) and Pioneer Valley (PV) basalt (plagioclase > augite > quartz > chlorite). Powders of BR and PV basalts were sieved into 150 μm fractions, and experiments were ...