Natural Pozzolan and
Fly Ash Products

CR Minerals offers several grades of Tephra® to serve the construction and oil and gas industries as a natural pozzolan. Tephra® products have been tested, proven and certified as both a natural pozzolan as well as a fly ash conforming to ASTM C618 specifications. Several of our Tephra® products are also patented through the USPTO.

CR Minerals has a wide range of pozzolan products that are available from our growing network of plants and distribution locations.

Pozzolans have been used for millennia in cementitious materials dating back to the Roman empire. Their benefits have been well documented and include attributes such as improved concrete plastic properties, higher strength, lower permeability and resistance to both alkali silica reactivity (ASR) and sulfate attack. CR Minerals has a wide range of pozzolan products that are available from our growing network of plants and distribution locations.

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Tephra ® Products

CR Minerals maintains a growing portfolio of products, many of which are patented, that serve a wide range of applications in both the concrete industry as well as the oil and gas sector. Our products have been designed for optimal performance and deliver exceptional value to our customers and the ultimate end-users. From achieving high early strengths in some materials to significantly increasing long term durability in other products, our materials are on the leading edge of innovation in the industry.


Natural Pozzolan - Class N

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White Pumice Natural Pozzolan - Class N

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Remediated Fly Ash - Class F

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Remediated Fly Ash - Oil & Gas

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Patented Technology

With an ever-changing landscape to the availability of pozzolans for the customers that we serve, CR Minerals has patented several of our products for use in the concrete industry as well as the oil and gas sector. These patents offer product protection for our customers and ensures that the performance they receive is the same high-end design that was developed through years of product development. CR Minerals has been awarded the following patents by the US Patent and Trademark Office (USPTO) and continues to innovate with other technologies as we expand our intellectual property portfolio:



While much of our modern concrete infrastructure crumbles, ancient concrete relics of the Roman Empire stand as solemn witnesses to the building materials used during construction. Their secret to durability was natural pozzolan, a fine-grained volcanic material. The Pantheon, the Coliseum, the Aqueducts – all serve as ancient testament to the longevity of concrete which incorporated natural pozzolan. The chemistry behind their success was consuming excess calcium hydroxide, and converting it into additional binder, or Calcium Silicate Hydrate (C-S-H). Through this process, the pozzolan both strengthened and fortified the concrete, protecting it for the ages. CR Minerals Tephra® line of products uses these same principles to deliver enhanced engineering properties to our customers’ concrete.

Sustainable sourcing is at the core of what we do

Providing solutions and conducting our operations in an environmentally sound and sustainable manner is as important to our business as delivering value to our customers through our products.

Sustainable Practices

CR Minerals’ patented solutions use waste material (coal combustion products or CCPs) from coal fired power generating stations that would otherwise end up in landfills. Our beneficiation of this waste material is true landfill avoidance and can help our customers achieve LEED status or meet other sustainable environmental standards.


Power Generation Partners

The landscape of coal-fired power generation has changed dramatically in the last decade. As a nation, we have moved from an overwhelming reliance on coal-fired power to a more balanced industry where both natural gas as well as renewable power sources such as wind and solar have grown significantly.


Patented Technology Practices

One of the results of this changing landscape has been regional shortages of fly ash available for use in cementitious materials. This shortage has come from both the closure of coal fired power plants as well as the fly ash from other plants becoming non-spec material which can't be used in concrete. CR Minerals' patented technology uses this non-spec material to produce a remediated fly ash that not only can be used in concrete but can also deliver enhanced performance.

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