St. Cloud Mining

And St. Cloud Zeolite

Keeping it clean with zeolites for over 20 years


By Ania K. Swiatoniowski

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St. Cloud Mining Company, SCM, has been bringing high quality zeolite out of the ground and into innovation for over 20 years. Zeolites, a group of volcanic minerals, are often called “molecular sieves” because of their porous structures, making them valuable in a wide range of agricultural, environmental, and industrial applications.

A privately held, mid-tier industrial mineral company, SCM is the largest producer of high quality, high purity natural zeolite in North America, and one of the most profitable. The company produces 42-45,000 tonnes of natural zeolites annually.

SCM is a fully integrated company owning and operating all mines, operations and deposits as well as often working directly with clients on zeolite product innovation. The company is head-quartered in Winston, New Mexico.

“We own four separate deposits of zeolites,” explains Dan Eyde, President and Chief Technical Officer of SCM. “Each deposit has its own unique characteristics so each can be used in different applications.”

With 34 years’ experience in zeolite mining operations, Eyde’s enthusiasm for the zeolite industry is obvious as he talks. “Natural zeolites have been used for thousands of years in a lot of base applications, such as animal feed. The Romans used zeolites to build aqueducts. The Colosseum was built out of natural zeolites and pozzolanic cement. These structures lasted thousands of years. Some of the aqueducts are still in use.”

There are over 40 naturally occurring zeolite varieties, but all have a similar honeycomb-type structure with large internal surface areas. The honeycomb pores (0.3 to 0.7 nanometers in diameter, just larger than a water molecule) contain various positively charged atoms (cations) –such as sodium, magnesium, or potassium– and water molecules. Zeolites are often described as “molecular sieves” because they can separate larger molecules, “filtering” ones too large or the wrong shape to get through its pores. The cations within the pores have high “cation exchange capacity” (CEC), allowing them to swap places with molecules in a substrate. These characteristics makes zeolites very effective both for filtering media (removing undesirable compounds) but also for delivery systems (adding desirable compounds).


While still used in cement production today, the modern list of zeolite innovations has bloomed into a huge variety of applications. Using only four of the natural zeolite varieties, SCM has tapped into multiple industries including agriculture, aquaculture, water treatment, air and gas treatment, industrial, and soil and turf industry applications.



Zeolites and the Fukushima Daiichi Nuclear Disaster

In March 2011, as the Fukushima Daiichi nuclear disaster hit the news worldwide, St. Cloud Mining was already working with Kurion Inc. on developing zeolite applications for cleaning difficult radioactive wastes and supplying the company with zeolite media. SCM had been working with and supplying zeolite to Kurion –a company specializing in permanent disposal of nuclear and hazardous wastes– since late 2010.

“My initial reaction was “how can we help?” recalls Eyde. He had seen nuclear meltdown before. Eyde had been a consultant to Union Carbide Corporation, supplying them with zeolite from the Bowie deposit during the Three Mile Island (TMI) clean-up operations in Pennsylvania. At Kurion, Dr. Mark Denton, who also worked on the TMI clean-up, was working on new, more effective zeolite applications for radioactive waste clean-up.

“We had papers, publications, and data to show that the ion exchange zeolite media would be effective [at Fukushima],” explains Eyde. Kurion, using St. Cloud Zeolite and their proprietary processing techniques, was responsible for 70% of the clean-up of water in the first nine months after the disaster.

SCM’s involvement of zeolite media supply is on-going and the company continues to be one of the largest suppliers of media to the Fukushima disaster.

All Zeolites Are Not Created Equal

The Winston Deposit and Operation is SCM’s main facility. Located just south of Winston, New Mexico, the operation produces 35,000 tonnes of calcium potassium clinoptilolite zeolite annually. The site is fully integrated, containing a surface mine, storage and impoundment facilities, and a zeolite processing plant.

Half of the Winston clinoptilolite goes to agricultural products. Zeolites are widely used in agriculture with SCM serving as a major provider to the industry.

Agricultural applications of St. Cloud Zeolites include addition of the zeolites to feed in Concentrated Animal Feed Operations (CAFOs). This increases feed nutrient value, helps manage nitrogen and ammonia emissions, and improves quality of manure. In horticulture, zeolites are used as “time release capsules” for more controlled application of nutrients, hydration, and pesticides to crop soils. The zeolite medium releases the nutrients, water, etc slowly over time producing better crop results and reducing run-off.

“[These soil additives] often don’t stay strictly within the boundaries of the farm. That’s where you get phosphate fertilizers getting into streams, [run-off]. It’s the same thing in municipal water treatment plants. Wastes come in and mostly they’re treated, but some substantial portion of them still gets away. These are two areas that we think zeolites will continue to have a growing, important role,” explains Eyde adding that St. Cloud Mining will be there and ready to capture that market as it grows.

Most of the remaining half of the Winston Operation sales go to water treatment and filtration in industry and in municipal water treatment and for mine reclamation applications for removing heavy metals and Acid Mine Drainage across North America.

SCM has been expanding their assets beyond the Winston Operation with an eye on growth, acquiring the following three additional deposits in the past four years. These acquisitions mark a period of significant growth for the company and ensure that SCM has many years of productivity to come. At the Bowie, Ash Meadows, and Rome deposits drill tests indicated proven reserves are large, in excess of a million tonnes at each location. At the Winston Operation the measured resources of clinoptilolite in the current and planned pits also exceeds a million tonnes.

SCM’s Ash Meadows deposit in Nevada and California produces sodium potassium clinoptilolite, a less common zeolite used in many speciality products. It is especially sought after as filter media because its high cation exchange capacities (CECs) make it particularly effective in trapping molecules in air and water. The site also houses a processing facility which handles SCM’s speciality product processing.

After acquiring a substantial portion of the Bowie Operation in Arizona, SCM has worked towards the commercialization of the Bowie chabazite in emerging specialty sorbent and catalyst innovations, used primarily for environmental and industrial clean-up. It is also sold for use in lightweight concrete and shotcrete. The Bowie Operation is the only operating high-purity chabazite deposit in the world.

The Rome Deposit in Oregon contains approximately 2 million tonnes of mordenite in drilled out reserves. One of the rarer zeolites, mordenite is lightweight and has a very high sorpency. This deposit is not yet in commercial production.

Beyond zeolites, SCM also owns a saponite clay (magnesium bentonite) deposit at Burro Creek, Arizona.

As Eyde talks about the many uses of zeolites and SCM’s continuing growth, one thing about the company stands out: SCM is a company that understands markets and demand.

“St. Cloud has a different marketing approach. We don’t market directly to end users, we market to people who work with us or who take our products to develop new markets for them,” explains Eyde. These partnerships in innovation have given SCM an edge in taking advantage of emerging markets in various industries.

“We work diligently at insuring we provide the best and most consistently performing products for these applications from our deposits,” concludes Eyde.

Consumption of zeolites in the US has seen an increase of over 20% from 2009 to 2013 (United States Geological Survey) and Eyde predicts that the demand will continue to grow, particularly in agricultural and in environmental applications. SCM has been keeping up with this trend by steadily adding to their assets, building partnerships, and working towards innovations development.



Resources Quarterly - Fall 2014

This article originally appears in the Fall 2014 edition of Resources Quarterly.

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