What is Gilsonite?

Gilsonite is a natural, resinous hydrocarbon. This natural asphalt is similar to hard petroleum asphalt and is often called a natural asphalt, asphaltite, uintaite, or asphaltum. Gilsonite is soluble in aromatic and aliphatic solvents, as well as petroleum asphalt. Due to its unique compatibility, Gilsonite is frequently used to harden softer petroleum products. 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.
Gilsonite 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, Gilsonite 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.
The life cycle of asphalt mixtures (surfacing layer) can be determined by measuring the fatigue and stress characteristics including permanent deformation resulting from traffic loading .Therefore, improving the quality of the asphalt mixture such as rutting resistance and moisture damage will lengthen the pavement service life, thus, accordingly enhancing the sustainability. Hot Mix Asphalt (HMA) is an essential material in the paving industry and offers several advantages including versatility, good durability, and cost-effectiveness . HMA is a combination of two primary ingredients: aggregates and asphalt binder . HMA deteriorations including aging, low temperature, and fatigue cracking, rutting, and moisture-induced damages are mostly due to the mechanical and rheological properties of the binder and asphalt mixtures . The global consumption of asphalt binders has rapidly increased since the 1900s, being used mostly as the binder for asphalt mixtures for road construction and maintenance .
Poor asphalt not only reduces the pavement service life but also causes further issues, for example, increased repair, premature failure, increased maintenance costs.

History of Gilsonite

Gilsonite, the scientific name of which is “uintaite”, was discovered in the 1860s, and later referred to as “gilsonite” after Samuel H. Gilson . Gilsonite is also referred to as asphaltum, natural asphalt, mineral asphalt binder, asphalt binder powder mineral tar, or drilling mud.
Gilson’s promotion of the ore was so successful that, in 1888, he and a partner formed the first company to mine and market on a commercial scale. Originally,it was sold as “Selects” and “Fines”; the low softening point ore with conchoidal fracture was known as “Selects”. The higher softening point ore with a pencillated structure was known as “Fines”. Selects commanded a higher price than Fines because of its better purity, good solubility, and usefulness in the paint, stain, and varnish industries. Time and technology have changed this classification system. Processing now removes most of the inert contaminants and newer, more powerful, solvents make the higher softening point grades more interesting to the user. Today, it is graded by softening point (a rough measure of solubility) and particle size. All grades carry a degree of quality far superior to those first small amounts marketed in the 1880’s.

Gilsonite Appearance

This shiny black substance is fragile and has a brown color when pulverized. Although its black color is only evident in mass amount of gilsonite and its shininess occurs only when it is fresh and becomes dull weathered. The color isn’t a basis for grading but gilsonite is classified as the size and softening temperature point.

Advantages of Nutural Asphalt

• Readily soluble without heating in aromatic solvents and in most chlorinated solvents
• High Asphaltene content
• High solubility in organic solvents
• High purity and consistent properties
• High molecular weight
• High in resin and Nitrogen content

Advantages of Gilsonite in Drilling Fluids

• It is used in sensitive areas
• Avoid damaging radial drilling parts
• Cleans the surface of the wells and removes sludge
• Prevents bullets or heavy soil compounds
• Controls fluid loss and seepage
• Stabilizes shales
• Prevents lost circulation
• Promotes effective filter cake development
• Minimizes differential sticking
• Performs in oil- and water-based drilling muds
• Strengthens the wellbore to increase wellbore stability
• Performs in HP/HT environments
• Minimizes HSE risks
• Ability to work in very high-temperature environments (the high softening point between 175 and 235 degrees Celsius)
• Prevent damage to drill parts
• Prevent oil-based drilling mud from sticking
• Polishing the surfaces of drilling wells and removing excess flowers and drilling sludge
• Prevent pelleting or massing of rocky soil compounds

Nutural Asphalt Suppliers

There are numerous suppliers of Gilsonite from different origins including the USA, Iran, Colombia, and Albania. From USA major supplier with over 50% market share is American Gilsonite company while from Iran there are over 100 suppliers which can be shortlisted into 5 companies eventually with the necessary infrastructure to export Iranian Gilsonite, Zista Gilsonite included as most of these suppliers are actually one advertiser for other company without having any financial nor technical resources.
In Colombia mining operations are active but exporters are few with the main target as the USA for direct consumption or for blending with other materials and processing into final products in the case of the American Gilsonite company. Albania Gilsonite suppliers are still primitive and quality control is a big issue in addition to the commercial complexities of dealing with any Albanian Exporter.
Gilsonite is used in cementing slurries to provide density control, scouring action for mud removal, and support compressive strength development. It has a unique reaction with shale that improves cement bond development and strength. The wellbore is the primary hole on which the final well will be made. Also, wellbores can be encased by steel or cement or in some cases, depending on the situation, may not be encased. In oil wells, it is necessary to encase the wellbore with cement. Adding the Gilsonite material during oil well cementing enhances the isolation characteristics while decreasing the vertiginous Gas flows. These characteristics can result in more effective mud removal which also enhances the environmental factors. Drilling environmental regulations are getting more and stricter around the world.

Nutural Asphalt Characteristics

Gilsonite has a melting point between 120°C to 230°C, very good insulator qualities, high purity properties and is soluble in organic solvents. All these characteristics leads it to be a substance with wide variety of uses. It is used in paper, ink, paint and polish industries. In oil and gas drilling fluids, asphalt and roofing asphalt, cementing, fireworks and many other applications, gilsonite is used.

Critical Evaluation of Gilsonite as Asphalt Modifier

A wide range of gilsonite has been added to the asphalt binder and asphalt mixtures by wet and dry processes, respectively. Different processes and range of sources may contribute to the different performance properties of the modified asphalt mixtures. For example, Quintana et al. used high purity gilsonite and had a low carbon and sulfur content , compared with other studies where the gilsonite had higher carbon and sulfur contents .

Compared to the control asphalt mixtures, modified asphalt mixtures in the wet process provide better performance properties . However, the dry process is cost-effective and it is much easier for a manufacturer to produce the asphalt mix as it does not need mixing tanks . A modified wet process was used in most of the research, and the reviewed studies indicated that gilsonite asphalt pavement using the wet process exhibited good performance .

The methodologies have been developed and subjected to numerous research investigations. Several tests were conducted to assess the performance of the resulting products following different standards. Physical properties tests such as penetration, softening point (SP), ductility and viscosity were the common tests considered by most of the reviewed studies to evaluate the rheological properties of modified binders. According to the reviewed studies , adding gilsonite mitigated the penetration value and increased the softening point, ductility and viscosity values; based on these test results, modification of the asphalt binder with gilsonite can increase the quality of the asphalt mixture. However, increased viscosity of modified binders led to escalated mixture and compaction temperatures . Therefore, gilsonite modification can lead to binder oxidation and decline of the design life because of reduced flexibility and cracking fatigue . Therefore, adding another additive, such as waxes, to the gilsonite-modified binder was necessary to decrease the viscosity.

The Process of Natural Bitumen

When used on a drilling rig, the drilling mud is pumped from mud pits, which is where the fluid is held, and through the drill string. From there, it cleans and cools the drill bit by spraying out of nozzles on the bit. Next, the mud takes the cuttings, which are crushed rocks produced from drilling the well, and is taken back up the annulus back to the surface. The cuttings are then filtered out and the mud returns to the mud pit to be treated.

Health, Safety, and Enviromental Advantages

The employees of American Gilsonite are our most valuable asset. To ensure the health and safety of our workforce, our management team established a continuous improvement program focused on building a strong safety culture. We believe that a safety culture extends far beyond the worksite, and is a lifestyle decision that lies within each of our employees to look out for themselves, their coworkers, and their families. We also feel that a strong safety culture provides an opportunity for positive communication and relationships across all levels of the organization; which sets the stage not only for a safe environment but for a workplace that is positive, efficient, and effective.
Gilsonite has significant health advantages over synthetic products like:

• Non-toxic (unlike coal or fly ash)
• Non-carcinogenic
• Non-mutagenic

Economic and Environment Assessment Gilsonite

The criteria considered in this study for the assessment of economic and environmental aspects are the use of gilsonite alone and in combination with other additives in the asphalt industry.

From the economic perspective, the better quality and longer life of pavements satisfy both safety and economical aspects . The use of gilsonite improves asphalt mixture resistance against tensile stresses, resulting in an increase in the service life of the pavement and a reduction in repair and maintenance costs . Likewise, gilsonite is an appropriate alternative and economical choice for enhancing the properties of the binders ; for example, gilsonite is less expensive compared with other modifiers such as SBS or EVA (Ethylene-Vinyl-Acetate) . According to the resilient modulus results, gilsonite demonstrated higher performance compared to asphalt mixtures made with pure asphalt binder . This outcome could have a significant influence on the economic design of roads because of the need in asphalt pavements to have resilient modulus . Moreover, the increased resilient modulus of the mixtures containing gilsonite may reduce the asphalt layer thickness, resulting in improved resistance to heavy traffic loads, and extended service life of the pavement.

From an environmental perspective, the asphalt industry process plays an important role in contributing to the causes associated with global greenhouse gas emissions . Therefore, asphalt industries are actively searching for alternative materials and techniques in order to move towards sustainable development. Considering the amount of recycled material included in the asphalt mixture, gilsonite increases the performance of the porous HMA when using 100% recycled concrete as aggregate ; therefore, it is a potential material for sustainable pavement systems. However, adding gilsonite to the asphalt binder decreases the penetration value and increases the SP and viscosity . This leads to increased mixing and compaction temperatures , resulting in increased energy consumption and associated CO2 emissions.

Effects of Natural Bitumen on Performance Properties of Bitumen

The effectiveness of natural Gilsonite on the performance properties of modified bitumens was studied. Three samples having different ratios of Gilsonite that are 6%, 8% and 10% by weight of base bitumen which was PG 64-16 grade were prepared. The physical properties and storage stabilities of four samples were investigated by means of conventional tests. The short-term and long-term aging processes of bitumens were conducted with rolling thin oven and pressure aging vessel tests, respectively. Rheological properties of bitumens were examined by means of Superpave tests such as rotational viscosity, dynamic shear rheometer and bending beam rheometer. After the rheological study, the low and high temperature performance classes of bitumens were determined by the Superpave specification. The results showed that natural Gilsonite-modified bitumens provide improvement in rheological and physical properties of bitumen, and were found highly compatible with base bitumen. Gilsonite additive significantly increased stiffness and viscosity of bitumen, and improved the resistance against fatigue cracking and rutting of bitumen, without causing a reduction in thermal cracking resistance of bitumen.

Applications of Gilsonite

Drilling Fluid Loss Control: 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.

Oil Sector: Gilsonite is used in drilling mud fluids and oil well cementing. Gilsonite, in a range of softening points and particle sizes, is a standard ingredient in oil-based drilling muds used in shales and other difficult geological formations. The addition of specially-treated Gilsonite to water-based drilling fluids helps minimize hole washout by stabilizing troublesome shales, and seals off highly permeable sands while reducing torque and drag. The addition of Gilsonite to oil well cements reduces slurry weight without loss of compressive strength and acts as an effective bridging and plugging agent to seal fractures in weak formations while cementing.

Asphalt and Road Paving Sector: 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.

Foundry Sector: 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.

Chemical Products Sector: 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.

Inks and Paints Sector: 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.

PACKING SPECIFICATION

Gilsonite/Natural Bitumen Packing Bags is a kind of flexible Intermediate Bulk containers, also known as Gilsonite/Natural Bitumen Big Bags or Gilsonite/Natural Bitumen Bulk Bags. PP and PE is their main material. It applies to ship bagged Gilsonite/Natural Bitumen for long-distance or ocean transport. The main specification for short-distance transport is 1Ton and 1.5Ton, Jumbo Bags for export ocean transport. You can customize the waterproof, dust-proof, and, radiation-resistant bags as per your requirements as its excellent performance like moisture-proof function. It is the ideal product for the ore industry with characteristics such as 5-5.7 times safety factor, high strength structure, easy handling, operation, etc.

•  Kraft bag on the pallet
•  AD Star bag on the pallet
•  AD Star bag in the jumbo bag that can be placed on a pallet
•  Micronized Powder in the jumbo bag
•  Ordinary bags with the capacity of 25 Kg that can be placed on a pallet
•  Ordinary bags with the capacity of 25 Kg in the jumbo bag that can be placed on a pallet