Patent ID: 8177909

Claim:
A method for making a composition, comprising: (a) contacting a solution comprising a proton removing agent with CO 2 gas to form a CO 2 charged water; (b) contacting an alkaline earth-metal containing water with the CO 2 charged water; and (c) subjecting the alkaline earth-metal containing water of step (b) to one or more conditions to make a composition comprising hydraulic cement, the hydraulic cement comprising at least 47% w/w vaterite, wherein the composition upon combination with water, setting, and hardening has a compressive strength of at least 14 MPa, wherein the one or more conditions are selected from the group consisting of mixing, stirring, temperature, pH, precipitation, residence time of the precipitate, dewatering of precipitate, washing precipitate with water, ion ratio, concentration of additives, drying, milling, grinding, storing, aging, and curing.