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Our Solution


We convert atmospheric CO₂ into carbonate minerals using highly reactive minerals in steel slag aggregates 

The aggregates are applied on gravel roads, where they react and passively remove CO₂ from the atmosphere without additional energy inputs

Our CO₂ removal process

1. Steel production produces alkaline minerals called steel slag.  

2. Steel slag aggregates are applied on gravel road surfaces. 

3. Atmospheric CO₂ rapidly reacts with steel slag rich in Ca/Mg Hydroxide, producing permanent carbonate minerals. 

Measurement, Reporting, and Verification (MRV) is at the core of what Alkali Earth does in directly quantifying permanent carbon removal. We use simple measurements of total inorganic carbon to quantify carbon removal directly in all of our projects.

Permanent carbon removal is an essential component of a net-zero or negative emissions strategy.

(Source: IPCC, 2018)

Carbon removal made simple

To reach international agreements on climate change, we must remove billions of tonnes of carbon from the atmosphere every year beginning in the 2030s. 


Alkali Earth offers a scalable, low-cost approach to carbon dioxide removal by using enhanced weathering and mineralization of alkaline minerals in gravel roads.


We capture CO₂ as calcium carbonate directly in the aggregates we deploy.  This makes measurement simple and cost-effective because we only measure the accumulation of carbon in the roadbed.  

We use steel slags because they have some of the highest capacity for CO₂ capture and react faster than nearly all naturally occurring minerals. 

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