【Needle Coke】Advantages and Preparation Methods

Needle coke has the advantages of high conductivity, low coefficient of thermal expansion (CTE), low sulfur, low ash content, low metal content, and easy graphitization. It is a high-quality carbon material mainly used in the production of HP(high-power) and UHP(ultra-high-power) graphite electrodes and lithium-ion battery anode materials. 

The production of needle coke mainly involves three key processes:

① Formation of a wide-streamline intermediate phase at a temperature of 350 to 400 ℃. In this stage, small spherical intermediate phase forms and continuously grows and merges, undergoing a transition from isotropy to anisotropy in optical properties. ②. "Gas flow pulling coke" drives structural changes. In this stage, the bulk structure of the intermediate phase is rearranged and further solidified under the action of pyrolysis gas, forming a basic fibrous needle-like structure. ③. Calcination treatment to improve the performance of needle coke. Heat treatment can further remove volatile components from raw coke, causing coke shrinkage. The true density, mechanical strength, conductivity, etc., are further improved.

In recent years, with the introduction of the domestic supply-side structural reform policy, the proposal of ‘carbon peak and carbon neutrality' goals, the country has vigorously promoted the transformation and development of the steel and automobile industries. The rapid development of electric arc furnace steelmaking technology and new energy vehicles, supported by policies, has led to a sharp increase in demand for UHP graphite electrodes and lithium-ion battery anodes, thereby driving the rapid development of the needle coke industry. China's needle coke industry started in the 1980s, and with the unremitting efforts of major universities and research institutions nationwide, the industry has grown from scratch, with production increasing year by year, currently ranking first in the world. However, there are still some quality issues with needle coke products in China, making it challenging to meet the requirements of ultra-high-power graphite electrodes. High-quality needle coke still needs to be imported to address this. Contact us to learn more technical guidance of Needle coke products.