Rolling Into New Developments: Ball Milling at Progressive Planet’s Showcase Station Seven

Station Seven of our Progressive Planet Showcase tour highlights one of the most important pieces in our AgTech Plant line up: the ball mill.

This colossal piece of equipment is designed for milling minerals into fine powders. For agriculture, this process increases the surface area of the minerals, which in turn makes the nutrients more bioavailable for absorption by targeted crops. ?When the particles are ground finely enough, they can be mixed in a liquid suspension and applied to the leaves of the plants.?This foliar feeding process is known as “fertigation” (a neologism combining “irrigation” and “fertilization”) and can be an important component in regenerative agriculture.

A variety of natural minerals can be micronized for agriculture, and these provide healthier alternatives to synthetic fertilizers; either individually or as part of a mineral blend. Limestone provides calcium carbonate to plants, improving the uptake of other nutrients, and adjusting the pH of the soil. Soft rock phosphate is a source of calcium and phosphorous.?Zeolite, a natural aluminosilicate derivative of volcanic ash, conditions soil through water and nutrient regulation and improves compaction.

This same ball mill can be utilized to turn zeolite and diatomaceous earth natural pozzolans from our owned quarries into fine powders for the cement and concrete industry. When finely ground, the pozzolans become more reactive when mixed with Portland cement, delivering exceeding benefits to concrete performance.

The mill contains 23,000 pounds of steel balls in a gargantuan cylinder that rotate and pulverize the minerals into fine powders. The incredible amount of weight in the ball mill requires a rock-solid base on which to operate.?In May of 2022, Progressive Planet purpose-built a three-foot thick concrete platform, reinforced by a subterranean steel framework, to which the mill is now securely bolted. Included in a small section of this concrete pad is the first commercial application of PozGlass? 100G.

There is an art to ball milling, with speed control being crucial.?If it’s too slow, the balls accumulate at the bottom of the mill and do not tumble.?When it’s too fast, centrifugal force will fling the balls against the interior wall of the cylinder and they won’t tumble.?At the correct speed, the balls travel partway up the cylinder and then tumble down to the bottom, pulverizing minerals in the process.?Speed and time can be varied to produce particles of desired sizes. PLAN partners with organic producers and fertilizer distributors to provide powders and mineral blends that are custom-milled to individual specifications.

PLAN is now well equipped to increase our contribution to regenerative agriculture and low carbon cements. As announced in our news release?last month, the mill will be fully operational and producing orders for our partner customers in October 2022.?