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ASBUTON
What is Asbuton? Define Asbuton is an occurrence of asphalt bearing rocks or asphaltic rocks which might be considered as one among the largest asphalt deposits in the world.
Where in the world are other natural deposits to be found? Other natural asphalt-like, or better yet, tar-like deposits can also be found in Venezuela, Trinidad, Canada and the USA.
Is Buton natural asphalt commercially viable? Asphalt-like deposits found elsewhere in the world are either below water, of a quality not suitable for use in the road industry or are below the earth such that it can be mined, but at some expense, such as those found in the USA, called gilsonite. Asphalt in Buton island originates from crude oil in the depth that migrates upwards along deep seated faults and finally deposited asphalt vertically and laterally in the upper beds after the lighter fractions evaporate. In some places the light and heavy viscous asphalt are presently continuing oozing onto the exposed rock face on the surface.
Where can Asbuton be found? Asbuton can be found in a hilly and mountainous island called Buton situated just off the Southeast Peninsula of Southeast Sulawesi, Indonesia. In its crude, unrefined form, it is termed “oil shale” or natural asphalt. After extracted by separating non-asphalt materials content in Buton rock asphalt, it is named as Asbuton.
Asbuton is often connected to as oil shale. What is it? The term "oil shale" is a misnomer. It does not contain oil nor is it commonly shale. The organic material is chiefly kerogen, and the "shale" is usually a relatively hard rock, called marl. Properly processed, kerogen can be converted into a substance somewhat similar to petroleum. When walk through wet shale, it feels that the clay is sticking to shoes.However, it has not gone through the "oil window" of heat (nature’s way of producing oil) and therefore, to be changed into an oil-like substance, it must be heated to a high temperature. By this process the organic material is converted into a liquid, which must be further processed to produce an oil which is said to be better than the lowest grade of oil produced from conventional oil deposits, but of lower quality than the upper grades of conventional oil.
Is this "oil shale" inexhaustible? Explain why it is said or thought to be. The occurrence of asphalt fields means areas with many scattered different sizes exposed asphaltic rocks, and locally asphalt flowing up in wells and as seepages. Rocks with oil-odor and wells of light to heavy viscous petroleum oil along with emanation of H2S. Those flowing out of asphalt and oil to the surface are still continuing to the present due to the continuing regional tectonic pressure. According to the theory of plate tectonic, Buton Island is still subjected by regional pressure and as a consequence the formed asphalt and oil moves up continuously to the surface.
What is the coverage of the asphalt fields?
In south Buton alone, the
asphalt fields occur along down block-faulted zones of 5 to 7 km wide
that developed on the east side of a NNE In north Buton, the areas surrounding two districts are really underlain by beds which are susceptible for asphalt impregnation especially along the zone of their boundary.
What is the current volume of natural asphalt? Based on preliminary investigation including by applying geo-electric sounding, the asphalt deposit in just one area of north Buton is estimated 120,000,000 tons grading 10-30% impregnated bitumen by assuming specific gravity of 0.8. Locally, as heavy viscous asphalt of about 60% bitumen. The bitumen is impregnated in globigerina bearing limestone and marl.
Explain the nature of Asbuton in terms of its:
Composition of crude asphalt: Bitumen: 13 - 53 % Mineral Content: 28 - 30 %
Refined asphalt: Bitumen: 52 - 55 % Mineral Content: 35 - 39 %
Discuss the history of Asbuton. The early exploration of the asbuton deposits was carried out by mining engineers and geologists of the Nederlands Indies Geological Survey in the early 1920's to 1930's, with publication of preliminary results in the mid 1920's to late 1930's. The earliest reports were composed by Van Haeften (1924) and Zwierzycki (1925). Bothe (1928) reported on the some deposits areas, which because of their location were considered a favorite for development at the time. Hetzel (1936) reviewed the work to date and and outlined 19 "asphalt fields" or deposits and presented geologic and resource evaluation results for each deposit. Van Bemmelen (1949) in his treatise on the geology of the Indonesian archipelago reviews both the geology of Buton Island and the resources and origin of asbuton deposits.
Why does Asbuton become important? Asbuton is used as a modifier to enhance the properties of a bitumen-only pavement. It is mixed in controlled proportions with refinery bitumen to produce a blend that can yield as much as three times the service life that a bitumen-only pavement is expected to give.
What is the meaning of ‘penetration’ as applied to the asphalt paving industry? ‘Penetration’, as applied to the asphalt industry, is generally a measure of the hardness or softness of a bituminous binder. Laboratory equipment is used to test a sample of every batch of Asbuton that can only be delivered if it lives up to a certain penetration. Along with penetration, other parameters are simultaneously delivered.
How can Asbuton conform to a single standard yet deliver a range of penetrations? By blending in varying proportions, or by mixing with softer (higher penetration) or harder (lower penetrations) bitumen, a wide array of ASTM-designated Asbuton penetrations can be delivered. The Asbuton component of the blend remains untampered and uncompromised.
How is Asbuton processed? By extraction. Extraction process is a process of dissolving, whereas Buton asphalt rocks in certain shapes are dissolved in proper solvent, then the mixture is separated or re-taken using certain technology until asphalt materials remain and are further processed as according to market's specification demand. While the solvent, after separated from solid materials, is recycled and used for next extraction process.
What are Asbuton’s competitors? Several modifiers/enhancers now exist on the market, and although a lot of them barely live up to minimum specification, their proximity to the end user and their commensurately low performance: price ratio have generated increased market penetration in areas where these products are more readily accessible.
Discuss the use of natural asphalt as it occurs in China today. China is now the biggest natural asphalt customer. The Chinese government has seen the merit in investing in natural asphalt and is now using it in preparation for the 2008 Olympics. Other areas currently being paved with natural asphalt are Beijing and Guangdong.
What are the benefits of Asbuton? Compare it with derived bitumen The benefits of Asbuton include:
With all of these benefits, are there any limitations to using Asbuton over bitumen? Barring the issue of cost, there are only advantages. There is absolutely no drawback to using Asbuton. Indeed it is more expensive, but when one considers that, at a cost for Asbuton of 14% more than refinery bitumen, a service life expectation of up to three times as much, a savings to be accrued as a result of reduced maintenance of up to twice as much, and a resulting structural strength and load bearing capacity of up to 40 % more, then, in the context of the total delivered value, there are absolutely no drawbacks to Asbuton use over bitumen.
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