Successful Secret of Standing Out in Small Mining

The first requirement for a successful mine operation is a market for the product, metallic or nonmetallic. The second requirement is to deliver a quality salable product to that market for payment in an amount exceeding the cost of the operation. There are a vast number of mineral products, literally from A to Z, and there are an infinite number of ways to get them out of the ground and delivered in a form acceptable at the marketplace.

One may start by looking at what a particular industry needs, such as silica for glass or cement manufacture. Low-iron silica is desperately needed for making glass, and at least one California cement company would dearly love to see a prospector walk in the front door with samples from his nearby silica claims.

Another example, also nonmetallic, is bentonite clay, the water impervious material commonly mandated to line the floors, walls, and caps of landfill disposal sites. This material, which swells when wet, is extensively used in oil drilling mud. It frequently occurs along earthquake faults and it was along the Garlock Fault in Kern County that Joe Mathewson, a Los Angeles area resident, searched for the commodity in the 1980s. He found a suitable deposit on land next to Red Rock Canyon State Park east of Mojave. The swelling-type calcium clay was tested by independent laboratories and was determined to meet the low permeability specifications for landfill use.

Mathewson purchased the land, which had been actively mined during its pre-WWII years as the source of Old Dutch Cleanser kitchen and bath scrubbing powder. Over 120,000 tons of white, high-quality had been mined underground. It occurs as a layer over the pumicite, in places very close to the surface. The exposed edge of the clay overlooks Last Chance Canyon for thousands of feet. The layered beds in this portion of the Ricardo Formation dip twenty degrees northeast and plunge beneath Highway 14 to the north.

Mathewson had the pumicite tested for a variety of uses, such as an abrasive, a filler product, a pesticide carrier, and as a Portland cement additive. Investigations performed at the Mineral Research Laboratory, with the assistance of the Materials Testing Laboratory at California State Polytechnic University at Pomona, showed an increase in concrete strength using pumicite, but at an unacceptable cost.

Applications for a conditional use and operating permit for surface mining were submitted to Kern County and State of California officials in 1988 and after several revisions were approved in 1989. The Kern County Department of Planning and Development Services issued a Conditional Use Permit containing 46 major conditions required before, during, and after operating on the property. For several years truckload shipments were sent to an eastern market, but interest was weak. Meanwhile, the owner, determined to avoid capital expenses for equipment, located a contractor who would perform the necessary stripping and reclamation operations as needed, and truck the raw product to a distant mill for fine grinding. Removed overburden had to be carefully spread to conform to the existing topography and ground surface characteristics. In order to meet landfill specifications another contractor was hired to dry, crush, and by way of the on-site using a portable plant.