technology_Ao Hui Carbon

Introduction

Graphite electrodes

Graphite electrodes are made from petroleum coke after it is mixed with coal tar pitch.

They are then extruded and shaped, baked to carbonize the binder (pitch), and finally graphitized by heating it to temperatures approaching 3000 °C, at which the carbon atoms arrange into graphite.

Graphite electrodes are mainly used in electric arc furnaces.

They are presently the only products available that have high levels of electrical conductivity and the capability of sustaining the extremely high levels of heat generated in EAF. Graphite electrodes are also used to refine steel in ladle furnaces and other smelting processes.

Graphite electrodes are divided into 4 Types: RP Graphite electrodes, HP Graphite electrodes, SHP Graphite electrodes, and UHP Graphite electrodes.

Raw Material

Use of high-quality needle coke and calcined petroleum coke production materials

Crushing & Screening&Kneading

They are broken needle coke in mechanical equipment and screening according to the formula after the proportion of the ingredients. Ingredients of the raw materials with a certain proportion of asphalt heated kneading, made with plastic paste.

Forming

After kneading of the paste by temperature cooled to process, and forming into the compressor according to the requirements of product specifications

Baking

Within the roasting road, will be “green” electrode roasting to the specified temperature, according to the requirements of the process. After roasting products with special dipping, density, and mechanical strength, improve product performance in order to improve the products and then to repeat the roasting of impregnated products.

Impregnation

Impregnation is a process in which the carbon material is placed in a pressure vessel and the liquid impregnant pitch is immersed and penetrated into the electrode pores of the product under certain temperature and pressure conditions. The purpose is to reduce the porosity of the product, increase the bulk density and mechanical strength of the product, and improve the conductivity and thermal conductivity of the product.

Graphitization

Second after roasting the products within the graphitization resistance furnace power up to 3000 ℃, the carbon atoms rearrange into specific crystalline form structure, carbon into graphite.

Machining

The purpose of mechanical processing of carbon and graphite materials is to achieve the required size, shape, accuracy and so on by cutting, and to make the body and joint of electrodes that meet the requirements of use.

Usage

The graphite electrodes are primarily used to carry the electricity that melts scrap iron and steel in electric arc furnaces. As an increasing proportion of global steel is made using electric arc furnaces, the secondary production of steel becomes the major consumption of graphite electrodes. Additionally, the graphite electrode is also used in melting products in smelting furnaces, non-ferrous metals, ceramic products, and even the waste recycling industry. The demand for graphite electrodes is majorly dependent on its application in manufacturing steel through smelting by using an electric arc furnace (EAF). Steel manufacturers are shifting towards electric arc furnaces over the blast furnaces, owing to the advantages offered by EAF such as low cost of establishment, higher production flexibility, and low CO2 emissions.