APPLICATIONS OF CALCIUM SILICATES DERIVED FROM GEOTHERMAL RESOURCES

Abstract

We have developed a process to remove dissolved silica from geothermal brines in the form of a proprietary calcium silicate hydrate material (CaSil). By decreasing the level of dissolved silica in the brine below the silica saturation index, we can effectively reduce the formation of intractable silica sinter within pipework and associated equipment. The formed CaSil material does not adhere to pipework and can be recovered from solution, allowing the brine to be reinjected without risk of silica deposition in the reinjection well.
The recovered calcium silicate has a low bulk density and a high surface area, with the calcium component of the CaSil remaining chemically available. These properties make the CaSil amenable to incorporation into concrete materials based on Portland cement. The CaSil/cement composite materials are lightweight and have the potential to be used as construction materials.
This paper will discuss the properties of the composite materials and their potential uses.