About Hess Agrox

Hess Agrox is the Agricultural Products Division of Hess Pumice Products, located in Malad City, Idaho USA. Hess mines and refines pumice taken from a deposit recognized as the purest commercial deposit white pumice in the world.

Common Beginnings, Innovation-driven Dominance

Hess Pumice Products began like many pumice operations: crushing pumice at the mine site and shipping it to block plants. But founder Marion Hess’ son Marvin, a University of Utah-trained engineer, studied the pumice coming out of the family mine and realized they had a pumice deposit far beyond ordinary. He developed sophisticated crushing and grading processes and built a plant that allowed Hess to offer the ideal on-spec grades to industry for a wide variety of applications. Based on the naturally pure quality and consistent results of the pumice Hess was delivering to the performance-critical abrasives market, Hess Pumice Products expanded world-wide, shipping pumice products into over two dozen countries. On the foundation of that initial success, Hess Pumice has never stopped innovating, never stopped exploring possibilities and expanding the uses for their pure white pumice.

loading pumice into rail cars at the Hess Pumice plants

Whether shipping palleted bags or supersacks by via bulk-loaded rail cars or trucks, Hess ships pumice anywhere.

PRODUCT SPECIFIC GROWTH. In the decades that followed, Hess developed additional pumice product lines alongside their polishing abrasives grades, products that have gained solid footing in their respective industries. For example, a line of microfine pumice grades (Hess NCS) that work as a safe and functional filler for epoxies, caulks, paints and industrial coatings. Safe because, unlike the lung-damaging crystalline silica filler powders typically used in the paints and coating industries, microfine pumice powders are amorphous (non-crystalline in structure) and present no respiratory hazard. Functional because the grippy, sponge-like structure of pumice particles fully integrate and mesh into the polymer networks of various coatings, resulting in a much more functionally useful, structurally-reinforced pigment than is possible with typical platey extenders such as mica and talc.

POZZOLAN REBORN. Then came the concrete industry’s (re)embrace of natural pozzolans—and in particular, Hess’ pumice pozzolan—as highly effective Supplementary Cementitious Material (SEM). The inspiration for powdered pumice as a concrete-improving supplementary reactant in curing concrete came from the Romans, as did the term for such supplementally-reactive materials: pozzolans. Hess recognized the coming industry demand for a safe, clean, consistently effective, supply-stable concrete pozzolan to replace the widely-used, coal-fired-energy by-product known as fly ash. Hess already knew their pumice had excellent pozzolanic properties. Their pumice had been selected by the Department of Energy’s Sandia National Laboratory scientists as the key component (coupled with an ultrafine grind) in an innovative, long-lived cementitious grout they developed to seal the salt rock fractures deep underground in the DOE’s nuclear waste pilot plant depository in New Mexico. With a subsequent pair of university studies providing and quantifying the necessary data of the pozzolanic, concrete-improving effectiveness of the Hess pumice deposit, Hess went to market with two natural pumice pozzolan grades—Hess Standard Pozz and Hess UltraPozz.

HIGHLY VERSATILE, WIDELY APPLICABLE. Pumice is utilized in other industries and processes as well: cosmetics and beauty products (as an exfoliant), water treatment and filtration, blast mitigation, scrub-cleansing and polishing, lightweight aggregate in manufactured stone veneers, lightweight mortars and stuccos, and as texturizing grit for industrial coatings, primers, and gessoes.

THE AGRICULTURAL FRONTIER. The agricultural industry has yet to fully understand the benefits available from pumice with application across various segments and processes. The information collected on this website showcases ways pumice is currently being used in agriculture and horticulture, research from around the world that explores promising uses for pumice in the ag industry, and some common-sense speculation for application based on related uses pumice-alike products currently on the market.

TALK TO AN EXPERT. We know pumice. But more than that, we know pumice-related product and process development. We have a lot of experience working with innovative companies and individuals looking to develop new processes and pioneer applications that include pumice. We invest steadily in our grinding, grading, testing, blending, and packaging processes and equipment. Contact us to discuss the possibilities. We look forward to helping you get there.

Hess pumice production complex

The Hess Pumice Products campus in southeast Idaho, showing processing plants one and two, the offices, the lightweight stone production facility, and the heavy equipment/truck shop.

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