Electrochemical materials production and processing

A method for making a lime and a supplementary cementitious material, wherein the lime comprises calcium hydroxide, and wherein the supplementary cementitious material comprises SiO2, the method comprising:

• providing a source of electricity;
• selecting an input material to be processed, wherein the input material is a solid comprising at least 40% SiO2 by mass and at least 5% CaO by mass;
• using the source of electricity to power an electrochemical reactor that converts an aqueous salt solution into at least one acid solution and at least one base solution;
• using the acid solution to dissolve CaO from the input material, forming a suspension of insoluble solid particles comprising SiO2 in an aqueous solution comprising dissolved calcium ions;
• separating the insoluble solid particles from the aqueous solution using settling and/or filtration;
• using the base solution and the aqueous solution comprising dissolved calcium ions to perform a precipitation reaction, forming a suspension of solid particles comprising calcium hydroxide in an aqueous base-treated solution;
• separating the solid particles comprising calcium hydroxide from the aqueous base-treated solution using settling and/or filtration;
• and
• grinding the separated insoluble solid particles to a median major diameter less than about 10 microns and a specific surface area of greater than 10 m2/g such that
• the ground insoluble solid particles comprising SiO2 have a calcium hydroxide consumption of greater than 60 g calcium hydroxide per 100 g silicate using a thermogravimetric analysis calcium hydroxide consumption pozzolanic reactivity tests.