In the 1970’s Western Mud (now GEO Drilling Fluids, Inc.) wasIMCO Plant concerned about the continuing supply of Barite. The available supplies were all controlled by the largest mud companies and a price squeeze seemed possible. To protect against this vulnerable position, a number of mining claims with Barite deposits in the Sierra Nevada mountains were purchased, as well as a mill in Sacramento, to grind the ore into the familiar oilfield product.

The mill, known as Industrial Minerals Company (IMCO) has provided a wide range of products and services for the minerals processing industry and ceramic art markets since the early 1950’s. Located near the source of a variety of western clays, IMCO is well situated to mine, process and market our California resources.

About 1990, the mine was exhausted and closed. The remaining ore was ground and bagged and has all been used. The mill still belongs to GEO Drilling Fluids, but operates independently as Industrial Minerals Company (IMCO). As domestic Barite resources became scarer recently, we have purchased ore from China. This stockpile is used to grind and bag our own Baite.

Industrial Clays and Fillers

IMCO’s customers range from Fortune 500 manufacturers to small specialty companies. The grinding market includes fillers, binders, pigments, nutrients, environmental clays and other nonmetallic minerals. IMCO is able to reduce 8 inch ore to minus 325 mesh powder. Consistent sizing is accomplished by Raymond Roller Mills, air separators and screening equipment.

IMCO also grinds clay for industrial and agricultural applications. The latest and biggest project of IMCO is the Miravista shake program headed by Owens-Corning. IMCO provides filler for a molded roof tile. The tile is being made to look like wood shake, with a Class A fire rating and a 50 year warranty. This project has enormous potential and is much more efficient since the installation of a new Derrick high-frequency vibrating screen.

Processed materials are stored in covered areas for protection from the elements and are available in range of packaging from bulk to fifty-pound bags.Barite

Custom blending and packaging of dry powdered materials is available from IMCO in addition to technical support and product development services. Several of the GEO Drilling Fluids specialty products are custom blended here.

Lab & Field Coordination

Coordination of lab work and field work is achieved through the availability of laboratory services to all technical and engineering personnel on a local 24 hours basis, just as our engineers work. Assistance by laboratory management and technicians is always available should an abnormal condition occur.

During the process of drilling a deep well, with water base mud daily filtrate monitoring can be routine at the laboratory. In a matter of minutes, a complete determination of Cations and Anions can be performed with the aid of a computerized Atomic Adsorption Spectro-photometer and a pH-Ionalyzer.

This is extremely important when drilling with an inhibited mud system. We then provide, on a daily basis, a complete record of all significant Cations and Anions in the system.

In addition, we quite frequently, with the cooperation of the mud loggers and the operator, provide a complete analysis of Cation Exchange Capacities on drilled cuttings from spud to total depth.

Ceramic Clay

The mill now grinds clays and minerals for the ceramic industry. In addition to the mill, a major part of IMCO’s business has become the blending and batching of raw materials. IMCO supplies materials for companies that produce pottery, Ceramic Bagdinnerware, tile and art ware. Just about everything made with clay (literally including the kitchen sink) are made from products supplied by IMCO.


Leadership at the mill is provided by Eric Struck who worked as the Lab Manager for six years before taking over the front office. Eric graduated from UC Sacramento with a BS in chemistry and has worked in the ceramics industry for 22 years.

Other administrative employees include: Jerry Rott, Business Development Manager and Yvonne, Office Manager.

For More Information

Much more information about the products and services provided by IMCO can be found on their website. We encourage you to visit us at Industrial Minerals (IMCO) Website by clicking here.