Gilsonite in mass is a shiny, black substance similar in appearance to the mineral obsidian. It is brittle and can be easily crushed into a dark brown powder.It is found below the earth’s surface in vertical veins or seams that are generally between two and six feet in width, but can be as wide as 28 feet. The veins are nearly parallel to each other and are oriented in a northwest to southeast direction. They extend many miles in length and as deep as 1500 feet. The vein will show up on the surface as a thin outcropping and gradually widen as it goes deeper. Due to the narrow mining face, it is mined today, much like it was 50 or 100 years ago. The primary difference is that modern miners use pneumatic chipping hammers and mechanical hoists.
For many years, Gilsonite has been used in the oilfield as an additive in drilling fluids. Gilsonite, in various grades and formulations, has been used to combat borehole instability problems, provide lubricity, especially in highly deviated holes, and more recently as a bridging agent to combat differential pressure sticking and provide a law invasion coring fluid. It has been well documented that appropriately formulated Gilsonite products can minimize hole collapse in formations containing water-sensitive, sloughing shales and reduce stuck pipe problems by forming a thin wall cake and an inter-matrix filter cake. Gilsonite products are currently being widely used in water based, oil based, and synthetic based mud systems worldwide. Blended Gilsonite has proved to be very effective in all water-based systems.
Gilsonite is combined with coal and other ingredients as an additive in foundry sands to insure the quality of the molded part by improving mold release and the overall finish of metal castings.
Gilsonite combines with many other chemicals and materials that take advantage of its unique physical and chemical properties. Binder and coating applications in metallurgical, wood product, refractary and other industries further demonstrate the versatility and usefulness of this remarkable material.
Gilsonite is used as a performance-enhancing agent for asphalt mixes. Gilsonite-modified paving mixes achieve higher PG grades and incorporate perfectly into the asphalt blend with no need for high shear milling as is the case with many other modifiers. Gilsonite-modified asphalts have higher stability, reduced deformation, reduced temperature susceptibility and increased resistance to water stripping than non-modified asphalts. Gilsonite is also used to make both solvent-based and emulsion pavement sealers with superior appearance and weathering properties.
Gilsonite Resin is widely used as the primary carbon black wetting agent for black news inks and headset and gravure inks. Gilsonite Resin competes advantageously with petroleum-based hydrocarbon resins, phenolic resins and metal resinates, all of which it can complement or replace to various degrees. Various concentrations of Gilsonite Resin are used to manufacture law-rub-off news inks with superior gloss and tack properties. Special grades of Gilsonite called Selects are also standard ingredients in black ink formulations and are used as additives in asphaltic paints and varnishes.