Precipitated Calcium Carbonate (PCC) as Feedstock in Hydraulic Cement Production, and Hydraulic Cements Produced Therefrom
Methods of making a hydraulic cement are provided. Aspects of the methods include employing precipitated calcium carbonate (PCC), such as a CO 2 sequestering PCC, as a feedstock for lime (CaO) production. Also provided are hydraulic cements and concretes produced by methods of embodiments of the invention, as well as products produced therefrom. In addition, systems for practicing methods of embodiments of the invention are provided.
1 . A method of making a hydraulic cement, the method comprising employing precipitated calcium carbonate (PCC) as a feedstock for lime (CaO) production.
2 . The method according to claim 1 , wherein the method comprises calcining the PCC to produce the lime.
3 . The method according to claim 1 , wherein the method further comprises employing the lime in the production of a clinker.
4 . The method according to claim 1 , wherein the PCC is a carbon negative PCC.
5 . The method according to claim 4 , wherein the carbon negative PCC is produced by a CO 2 sequestering protocol.
6 . The method according to claim 5 , wherein the CO 2 sequestering protocol comprises direct air capture (DAC).
7 . The method according to claim 5 , wherein the CO 2 sequestering protocol employs gypsum (CaSO 4 ·2H 2 O) as a feedstock.
8 . The method according to claim 7 , wherein the gypsum comprises phosphogypsum.
9 . The method according to claim 1 , wherein the PCC is produced by an electrolytic protocol.
10 . The method according to claim 9 , wherein the electrolytic protocol comprises the use of an anion exchange membrane separating an anode chamber comprising an anolyte and a cathode chamber comprising a catholyte.
11 . The method according to claim 10 , wherein the anion exchange membrane is configured so that sulfate anion crosses the anion exchange membrane to the anode chamber where sulfuric acid is generated.
12 . The method according to claim 11 , further comprising maintaining a concentration of base in the catholyte that is low relative to the concentration of acid in the anolyte.
13 . The method according to claim 12 , wherein the method comprises recirculating fluid through the cathode chamber.
14 . A hydraulic cement prepared according to claim 1 , or a built structure produced therefrom.
15 . A system comprising:
a carbonate precipitation reactor configured to produce precipitated calcium carbonate (PCC); and
a calciner in a precipitate-receiving relationship with the carbonate precipitation reactor.