BRIMSTONE CEMENT
Company:
Brimstone
Website:
https://www.brimstone.com/
Location:
Oakland, California
Products:
Cement - calcium silicate rock based
SCM - magnesium silicate (?)
Technology:
Meets ASTM C-150 requirements for Portland cement. Involves HCl (hydrochloric acid) to prepare the product, and thermal treatment to produce the binder. Rotary kiln temperatures of up to 1450C may be required.
Steps:
1. Quarry the calcium-bearing silicate rocks
2. Crush the feed rock to the desired particle size.
3. Mix the crushed rock with chemicals (acids), separate, and dry. Separate the compounds for cement and alumina. Dry the residual silicate and process into SCM.
4. Heat the calcium compounds in a rotary kiln to produce clinker. Mill the clinker with gypsum to produce cement. Separately process the aluminum compounds to produce alumina.
Benefits:
No process emission like limestone-based cement. Immediate reduction of about 55% CO2 reductions from using non-CaCo3 materials. Unclear on energy consumption for the process to convert the meal into clinker. SCM and alumina produced as additional products. Magnesium compound (magnesium silicate?) sequesters CO2.
Possible disadvantages:
Capital costs and time of construction for commercial facility (scalability issues). Loss of large federal funding grant in 2025.
Status:
Pilot plant is rumored to be at some level of development - located near Reno, Nevada. Discussions for alumina production in Oklahoma, 2025. $189 million commercial plant funding by DOE was taken away in late 2025. Likely commercialization by 2030. 2025 announcement of "Rock RefineryTM" to produce multiple minerals.
TRL estimated at 7.
Production:
Current production at tabletop scale, about 250 Mt.