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ABSTRACT:

Extracting Silica from Geothermal Electricity Fluids

Geothermal aquifers are found all over the world and many are rich in dissolved silica and other valuable minerals.  In the geothermal energy world, silica scaling in reinjection pipes and wells is a significant problem for the geothermal power plant operators.  Geo40 has found a way to harvest the silica, turning a problem into a valuable product.

The Geo40’s process for making colloidal silica mimics what nature has been doing all along.  Steam is separated from hot geothermal water and used to generate renewable power.  The separated water is cooled in Geo40’s process and the dissolved silica becomes supersaturated forming colloidal silica nanoparticles.  The colloidal silica nanoparticles are filtered out of the water, washed of trace minerals and then grown using geothermal heat into final products.

The colloidal silica harvested from the geothermal water can be directly substituted in many processes for colloidal silica made using the incumbent process.  However, as Geo40 silica is derived from the waste of renewable power generation, it is near carbon neutral.  Furthermore, Geo40 can use post-processing methods to produce tailored speciality products such as string sols, alumina modified silicas, surface modified silicas and deionized acidic sols, depending on the customers' needs.

Finally, by removing silica from geothermal water clears up pathways for harvesting other valuable minerals such as lithium, boron, caesium, and antimony.  Geo40 is in the process of developing new technologies to harness these potential resources.

BIOGRAPHY:

Dr Campbell McNicoll, graduate Canterbury University with a PhD in chemistry focusing on titanium dioxide nanoparticles.  He then worked with an NZ based startup company developing a method to refine steelmaking slag into titanium dioxide pigment.  He was the lead scientist and saw the development of the chemical process from lab to pilot to demonstration scale. He then joined Geo40 where He developed colloidal silica products to meet market demands. Finally, while at Geo40, He designed and build the lithium extraction process/pilot plant, being one of the first to producing battery-grade lithium carbonate from geothermal brines.