Electrode Carbon Paste

Electrode Carbon Paste is produced by screening the CPC and or ECA to different fractions and pulverizing and storing it separately. Immediately after this the predetermined quantities of different fractions are weighed and transferred to a Sigma Mixer, which is heated to about 150 degree Centigrade by Thermic Fluid. The required quantity of the Binder is also weighed separately and the same is added to the Mixer. The mixing is continued for a particular period known as the Mixing Cycle. At the end of the Mixing Cycle, the mixed material is dumped on the mould box for casting into blocks for shipment.

The Paste is first fed in the upper part of the electrode. As the paste move downwards in the electrode it softens and melts and takes the form of the electrode casing. The flow of the Carbon Paste is essential for proper operation of the electrode, hence it is important that the Paste flows at a reasonable temperature and fills the casing of the electrode maintaining a consistent mixture of ingredients. The Paste then gets baked into a solid mass as it moves down and becomes capable of passing the required current for the furnace charge. The plasticity is a measure of its flowability which is controlled in a mixer by adjusting the Binder content or percentage of coke fines. The lower baked part of the electrode is the final electrode product. The physical properties of the Paste are of vital importance to ensure proper electrode operation without breakages.

Green Paste Volatile matter Fixed Carbon Ash Plasticity Apparent Density Binder Content Baked Paste at 1000deg Centigrade 12-13% max 84% Max 1.0% Max 30-45% 1.55gm/cc Min 22-24% Apparent Density Electrical Resistivity Compressive Strength Porosity 1.35 gms/cc Max 90 Ohm- meter Max 150kg/cm2 Min 35% Max

Green Paste Volatile matter Ash Plasticity Dry Aggregate Binder Content Baked Paste at 1000deg Centigrade 13% max 5.5% Max GradeI-45-55% GradeII-25-35% GradeIII- 30-40% 78-80% 22-24% Apparent Density Electrical Resistivity CCS 1.36 gms/cc Max 80 Ohm- meter Max 175kg/cm2 Min