Gilsonite Uses in Foundry
Foundries have been known for decades around the world. When contacted with the heat of molten iron, gilsonite provides high performance for the foundry sand. Gilsonite as a foundry sand additive in the preblend provides reduced smoke and emissions. Additives in the mixture consist of 1 part iron oxide, 1 part highly volatile carbonaceous material such as gilsonite and 4 parts of metallurgical coke. This is 1/4 of the foundry sand preblend. Other 3/4 consists essentially of clays.
For example, for castings that are high in the amount of iron, natural bitumen performs better than any other carbon additive. Also the naturally superior properties of gilsonite mean high-quality castings with better finish and fewer imperfections as gilsonite provides less reaction between mold and casting and better release from the mold.
According to PUB-LTD`s geological research, gilsonite was found in abundance in oil shale deposits. This is further confirmed by certain similarities in the composition of hydrocarbons involved. Generally gilsonite and shale oil have a nitrogen content much higher than petroleum oils.
Gilsonite is a natural hydrocarbon and one of the asphaltites, which are natural asphalt-like substances characterized by their high softening points (above 110°C). Glance pitch and grahamite are other members of this category. Non-mineral constituents are completely soluble in carbon disulfide. Gilsonite powder is soluble in aromatic solvents like benzene, toluene, xylene, without the need for heating.
The tests applied to gilsonite are in many cases almost the same as those used for asphalt.
Gilsonite is not a manufactured product, but a natural mineral and therefore it is subject to certain processings. We treat the liquid distillate from the pyrolysis of solid gilsonite with sulfuric acid to produce a nonreactive hydrocarbon fraction which was classified as paraffinic. Evidence for pyridines and quinolones in the distillate was apparently based on odor alone. Also there are several hydrocarbon fractions from gilsonite distillate with many properties similar to those of fractions from crude petroleum.
We identify the cycloparaffins (naphthenes) and olefins as hydrocarbon types. Furthermore, several phenols, pyrroles, and pyridines have been isolated in the pyrolytic distillate from gilsonite.
We obtained a heavy yellow oil from undegraded gilsonite in yields of 4-8%. Several aromatic and nonaromatic cuts, the latter predominating, resulted from low pressure distillation. Also silica gel adsorption of the oil is obtained.
We indicate the substituted naphthalenes in the aromatic fractions by uv spectra. Destructive distillation of Gilsonite gave 12 wt % gasses, 55 wt % of a liquid pyrolyzate, and 33 wt % coke.
We also isolate porphyrin fractions from ores of two different veins in yields of 0.03 and 0.004% (eg, deoxyphylloerythreoetioporphyrin). The entire porphyrin content is present as a nickel complex. The presence of porphyrins suggests that gilsonite is of plant origin.
Methods of mining include traditional mining with manual tools, pneumatic applications, blasting, and high pressure (up to 13.8 MPa or 2000 psi) hydraulic cutting. We use all methods concurrently in different mines depending upon mine conditions, elevating and surface handling requirements.