7 Different Uses of Graphite

Graphite exhibits a remarkable range of uses that might seem contradictory at first glance. As an allotrope of carbon and one of the softest minerals known, it serves diverse functions—from being the core material in writing instruments to acting as an effective lubricant.

Beyond these traditional applications, graphite can be transformed into graphene, a one-atom-thick cylindrical form noted for its exceptional strength, which finds utility in sports equipment. Interestingly, graphite demonstrates dual characteristics: it can conduct electricity like a metal, yet also behave as a nonmetal capable of withstanding high temperatures.

In nature, graphite is found either as flakes and veins within rock fractures or as amorphous lumps. Its fundamental crystalline structure consists of flat sheets of carbon atoms arranged in hexagonal patterns. These sheets, known as graphenes, stack upon one another to form the bulk material, but the bonds between these layers are relatively weak. This weak interlayer bonding allows the sheets to easily slide over each other.

Remarkably, when a graphene sheet is carefully aligned and rolled horizontally, the resulting material possesses a strength approximately one hundred times greater than that of steel.

Uses of Graphite

Graphite finds application in various fields, including pencils, steel production, and electronic devices like smartphones. Among these uses, its role in lithium-ion batteries stands out as particularly significant. In fact, graphite is present in quantities 10 to 30 times greater than lithium within these batteries, underscoring its critical importance in their composition.

These are some uses of graphite:

• Writing Materials
• Lubricants
• Paint
• Refractory
• Nuclear Reactors
• Batteries
• Graphene Sheets

1. Writing and Artists Materials

The term “graphite” originates from the Greek word meaning “to write,” reflecting its primary application in pencil manufacturing. Pencil cores, commonly referred to as “lead,” consist of a mixture of clay and graphite in an amorphous state. When used, the loosely bound graphite flakes leave marks on paper, while the clay serves as a binder. The softness of the pencil and the darkness of its mark increase with a higher graphite content.

Contrary to the common term, these so-called “lead” pencils do not contain actual lead. The misnomer dates back to Europe, where graphite was once called “plumbago” or “black lead” due to its metallic luster.

The practice of using graphite as a writing or marking tool can be traced back to the 16th century in northern England. According to local lore, shepherds employed a newly found graphite deposit to mark their sheep.

2. Lubricants/Repellents

Graphite is a key component in lubricants such as grease due to its unique properties. When exposed to atmospheric moisture, graphite interacts with water vapor to form a thin protective film on adjacent surfaces, effectively reducing friction. In oil suspensions, it decreases friction between moving parts, such as those found in car brakes and clutches.

As a lubricant, graphite remains effective up to temperatures of 787 degrees Celsius (1,450 degrees Fahrenheit), while it functions as an anti-seize agent at temperatures reaching 1,315 degrees Celsius (2,399 degrees Fahrenheit).

Additionally, graphite exhibits strong repellent characteristics, which has led many manufacturing companies to incorporate it into repellent formulations. Metal protectors, for example, commonly include graphite as a key ingredient.

3. Paint

If you have encountered paints that promise to protect walls, you have likely come across graphite as a key ingredient. In these paints, graphite is used in its powdered form. Manufacturers incorporate this powdered graphite into the paint to provide genuine and effective wall protection.

4. Refractories

Graphite is widely recognized as a refractory material due to its ability to endure high temperatures and maintain chemical stability. Its applications span various manufacturing sectors, including steel production, glassmaking, and iron processing. Additionally, graphite serves as a replacement for asbestos in automobile brake linings.

5. Nuclear Reactors

Graphite has a strong ability to absorb fast-moving neutrons, which is why it is commonly used to regulate and control neutron reactions.

6. Electrical Industry

Crystalline flake graphite finds application in producing carbon electrodes, brushes, and plates, which are essential components in dry cell batteries and various electrical devices. Notably, natural graphite undergoes processing to create synthetic graphite, a material particularly valuable for use in lithium-ion batteries.

In lithium-ion batteries, the cathode is composed of lithium, while the anode consists of graphite. During charging, lithium ions—positively charged particles dissolved in the electrolyte, which is a lithium salt solution—gather around the graphite anode.

Although a lithium anode could potentially enhance battery performance, lithium undergoes significant expansion when charged. This expansion leads to cracking on the surface of the lithium cathode over time, resulting in the leakage of lithium ions. These ions contribute to the formation of dendrites, needle-like growths that can cause short-circuiting within the battery.

7. Graphene Sheets

Rolled single-layer graphene sheets are approximately ten times lighter and one hundred times stronger than steel. Often simply called graphene, this form of graphite has been recognized as the strongest material known to date. Its remarkable strength and lightness have already found practical use in manufacturing high-performance, lightweight sports equipment.

Beyond its mechanical properties, graphene’s excellent electrical conductivity, minimal light absorption, and resistance to chemical corrosion position it as a highly promising material for a range of future technologies. Potential applications include medical implants like artificial hearts, flexible electronic devices, and components in the aerospace industry.

Application of Graphite

Graphite finds application in pencils and lubricants due to its unique properties. It conducts heat and electricity efficiently, which makes it valuable in electronic devices like electrodes, batteries, and solar panels. Additionally, graphite serves several industrial purposes, as outlined below:

1. in the Chemical industry

In the chemical industry, graphite plays a crucial role in high-temperature processes. It is commonly utilized in arc furnaces during the manufacture of phosphorus and calcium carbide. Additionally, graphite serves as an anode in certain aqueous electrolytic processes, including the production of halogens such as chlorine and fluorine.

2. in the Nuclear industry

High-purity electrographite is extensively employed in nuclear reactors, primarily for producing moderator rods and reflector components. Its suitability arises from its low neutron absorption, excellent thermal conductivity, and ability to maintain structural integrity under high temperatures.

3. Electrical applications

Graphite is predominantly used in the electrical field as a material for carbon brushes in electric motors. The performance and lifespan of these brushes are significantly influenced by the specific grade and microstructure of the graphite employed.

4. Mechanical applications

Graphite’s versatility as an engineering material is evident in its use across various mechanical components, including piston rings, thrust bearings, journal bearings, and vanes. Carbon-based seals made from graphite are also integral to fuel pumps and shafts in numerous aircraft jet engines.

4.1. Seal rings & Turbine rings:

These components work alongside graphite guide rings to seal high-pressure, oil-free gases. The appeal of graphite here lies in its self-lubricating nature, chemical inertness, high strength-to-weight ratio, and thermal stability.

4.2. Slip rings & Sliding rings

Slip rings are electromechanical devices designed to transfer electrical current between stationary and rotating parts. Graphite is favored in these applications for its electrical conductivity and self-lubricating properties, which help reduce wear over time and improve mechanical reliability.

4.3. Bearings & Bushings

Bearings support loads while allowing relative motion between parts, and bushings a specific type of bearing reduce friction between sliding surfaces. Graphite is chosen for these components due to its self-lubrication, durability, and ability to perform reliably in harsh operating conditions.

4.4. Vanes

Vanes, which are blades attached to rotating wheels that interact with air or water flow, benefit from graphite’s properties such as self-lubrication, high-temperature resistance, and chemical inertness.

4.5. Lubrication blocks

These blocks provide lubrication for rotary equipment like trunnion rolls, riding rings, tires, and insert seals where traditional wet lubricants are unsuitable. The weight of the graphite block ensures continuous contact with the rolling surface, depositing a thin lubricating film. Graphite is selected here for its self-lubricating ability and resistance to wear.

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