High Purity Artificial Graphite

High temperature resistance
The melting point of graphite is 3850±50°C and the boiling point is 4250°C. Even if burned by ultra-high temperature arc, the weight loss is very small, and the thermal expansion coefficient is also very small. The strength of graphite increases with the increase of temperature. At 2000°C, the strength of graphite doubles. The temperature of the chemical reaction that ignites the exothermic flux during the exothermic welding construction is very high, so the material used in the exothermic welding mold needs to be resistant to high temperatures.

Electrical conductivity and thermal conductivity
The electrical conductivity of high purity artificial graphite is one hundred times higher than that of general non-metallic minerals. The thermal conductivity exceeds that of metal materials such as steel, iron, and lead. Thermal conductivity decreases with increasing temperature, even at extremely high temperatures, graphite becomes an insulator. Graphite can conduct electricity because each carbon atom in graphite only forms 3 covalent bonds with other carbon atoms, and each carbon atom still retains 1 free electron to transfer charge. In the exothermic welding construction, it is often necessary to weld a lot of points, and the amount of construction is not small. The thermal conductivity of graphite can meet this point. It can withstand high temperatures and can quickly cool down.

Lubricity
The lubricating performance of high purity artificial graphite depends on the size of the graphite flakes. The larger the flakes, the smaller the friction coefficient and the better the lubricating performance.

Chemical stability
Graphite has good chemical stability at room temperature, and is resistant to acids, alkalis and organic solvents.

Plasticity
High purity artificial graphite has good toughness and can be rolled into very thin flakes. Exothermic welding sometimes requires exothermic welding molds of various joint forms. The plasticity of high purity artificial graphite can be manufactured into exothermic welding molds of different models, specifications, and connection forms.

Thermal shock resistance
High purity artificial graphite can withstand drastic changes in temperature without being damaged when used at room temperature. When the temperature changes suddenly, the volume of graphite will not change much and no cracks will occur.

Alkali acid purification method
The carbon content of graphite purified by the alkali acid method can reach more than 99%, which has the characteristics of less one-time investment, higher product grade, and strong process adaptability. Besides, it also has the advantages of conventionality and versatility. Alkali acid method is the most widely used method in China; Its disadvantages are large energy consumption, long reaction time, a large amount of graphite loss, and serious wastewater pollution.

Hydrofluoric acid method.
The main advantages of the hydrofluoric acid method are high impurity removal efficiency, high grade of products, small impact on graphite products performance, and low energy consumption. environment protection

Chlorination roasting method.
The low calcination temperature and the low consumption of chlorine gas make the production cost of graphite greatly reduced. At the same time, the carbon content of graphite products is equivalent to that of hydrofluoric acid treatment, and the recovery rate of the chlorination roasting method is higher than that of chlorination roasting. However, chlorine gas is toxic, corrosive, and requires high requirements for equipment operation, so it needs to be sealed strictly. Therefore, it must be properly treated for exhaust gas, so it is limited to some extent.

High-temperature method.
The biggest advantage of the high-temperature method is that the carbon content of the product is very high, which can reach more than 99.995%. The disadvantage is that the high-temperature furnace must be specially designed and built, the equipment is expensive, the one-time investment is large, in addition, the energy consumption is large, and the high electricity cost increases the production cost. Moreover, the application scope of this method is extremely limited due to the harsh production conditions. Only when there are special requirements for the purity of graphite products, such as national defense and aerospace, can we consider using this method for small batch production of graphite, and it can not be popularized in industry.

High purity artificial graphite is a material with very sensitive chemical reactions. Its resistivity will change in different environments; its resistance value will change. 

When there is a temperature gradient in the graphite, the flow of heat from high temperature to low temperature/the parameter characterizing the thermal conductivity of graphite is thermal conductivity/thermal conductivity in unit time. The proportional coefficient between the heat passing through unit area q (heat flow density) and the temperature gradient gradT/q=– λ grad T

● In the formula, the negative sign indicates that the direction of heat flow is opposite to the direction of temperature gradient/Formula (1) is often called the Fourier law of heat conduction. If the sectional area perpendicular to the x-axis is Δ S. The temperature gradient of the material along the x-axis is dT/dx Δτ Flow along the positive x-axis in time Δ The heat of section S is Δ Q

● The legal unit of thermal conductivity is W · m · K. For an unstable heat transfer process, the temperature in the object varies with time. For an object that has no heat exchange with the outside world and has its temperature gradient, the temperature gradient will tend to zero as time goes on. That is, the temperature at the hot end will decrease, and the temperature at the cold end will increase, eventually reaching a consistent equilibrium temperature. 

The company now has 2 modern production workshops and 2 large storage workshops, which can meet the needs of large-scale production and fast logistics. The annual production volume has reached 100,000 tons. After years of hard work, we have worked closely with many domestic companies and exported to many countries and regions. In the future, the company will continue to adhere to the business philosophy of "quality-oriented, honesty and trustworthiness", continuously improve product quality and service level, carry out extensive cooperation and exchanges with domestic and foreign companies, and jointly promote the development of the carbon industry.