LOCATION: Vancouver, Canada
SUMMARY: The mission of Terra CO2 is to disrupt the status quo of mine waste treatment by de-risking long term waste storage, producing value-added products from such materials, and developing better methods to prevent and treat water contamination.
PROBLEM SPACE: "Mining is necessary to satisfy the basic needs of all humans. However, the long-term environmental effects of mining are often at odds with the need to preserve water, soil and air-quality in the biosphere. Extraction and grinding of bedrock is a core process in mining that is necessary to liberate elements of value. This reduction of bedrock to silt/sand size particles also makes waste rock prone to leaching by surface and ground water. Common leachates include acid and/or metals that are harmful to the environment, can cause long-term contamination and represent significant liabilities to mining companies.
Metal-mining waste represents the largest (mass & volume) waste stream produced by human activity, and it is therefore imperative to the well-being of natural systems to manage this waste with the best methods possible. Unfortunately, innovation in this sector has been limited.
Many of the best available waste rock disposal techniques require permanent storage and active water treatment at their outflow in perpetuity. Lined and sealed impoundments are theoretically impermeable, but critics suggest this is hard to assure in all cases for >100-year time scales. There is an urgent need to adopt techniques that passivate and stabilize mine waste on a geologic time scale."
SOLUTION: "Terra CO2 has developed and patented processes for reducing long-term risk of tailings storage by dealing with the liabilities generated in the mining process up-front. We propose that extra measures for the prevention of water contamination will be the cheapest option in the long term (>100 year time-scale). In brief, our process consists of electrochemically producing alkaline solutions, reacting with atmospheric or industrial CO2 and precipitating water-polluting metals as stable carbonate minerals.
Terra is investigating the feasibility of coating individual reactive tailings particles with carbonate minerals. This creates redundancy because each particle is individually passivated. Passivating tailings up-front reduces need for impoundment, water treatment, and long-term risk of environmental damage. This may lead to additional up-front costs, but will reduce or eliminate long-term monitoring and treatment costs. Valuable byproducts such as sulfuric acid and recovered metal carbonates may provide additional off-sets. Iron carbonate is of modest value as an iron ore, but the embodied carbon captured by this mineral represents sequestered industrial or atmospheric CO2. If carbon prices rise in some jurisdictions to take into account the true cost of CO2 emissions (i.e., >$100/tonne) this process will become increasingly compelling. Thus the process is likely viable from a "whole-system" perspective."
CONTACT: [email protected]