The data set contains two separate items: (1) Global carbon dioxide removal potential of mine tailings, which includes (a) List of selected silicate-hosted mine tailings (classified by their targeted commodity and typical host rock) for initial assessment of CO2 removal (CDR) potential; (b) Estimated annual and cumulative production (Mt) of suitable tailings for host countries for the years 2030-2100; (c) Assessed deposit types and associated tailings mineralogies; (d) Summary kinetic data for typical targetable minerals in suitable tailings; (e) Effects of mineral compositional (and end member) variations on dissolution rates under unimproved conditions (Wr-Neut); (f) All compiled mineral data used in the GGREW global assessment study and other complimentary GGREW studies; (g) Estimates of dissolution extent over time (on decadal timescales of up to 70 years) for a theoretical 1 kg of tailings material at typical grain sizes and unimproved conditions (using Wr-Neut); (h) Total cumulative CDR (tCDR; MtCO2 as alkalinity); (i) Estimated CDR capacity (cumulative for the estimated annual tailings production at 2030 (sCDR) and total cumulative CDR (tCDR) as alkalinity for 2050 and 2100) for select countries that produce and host suitable tailings; (j) CDR achieved annually by country (2030-2100), under unimproved and improved conditions; and (k) Sources of information for modal mineralogies, commodity production to tailings production ratios and typical grain sizes for each potentially suitable tailings material type. (2) Results of enhanced weathering reactor optimisation with two objectives, namely energy consumption and space (area) requirement, which include the optimisation output for calcite weathering using trickle-bed reactor, calcite weathering using packed-bubble column and forsterite weathering using packed-bubble column. For each of them, the data includes key reactor design parameters, the two objectives, and key process characteristics (particularly, mass transfer performance and mineral dissolution rates).