This page was last updated on 09-July-2010
Carbon Anode and Mild Steel Stub Coating

To prevent Power/Carbon Loss in Aluminum manufacturing process

Material Required
Thermocoat (SEC-P) is a Super Electrical conducting coating withstanding temperature up to 2000 degree C. It’s Anti-Oxidation/Anti-Erosion metal application.

Aim of Coating

  • Power Saving.
  • Carbon Saving.
  • Reduction in production cost by increasing metal production without capital investment.

Advantages of Coating

  • It prevents stub surface (exposed to atmosphere) from oxidation and cryolitic attack.
  • It protects erosion of the top surface of anode.
  • It reduces millivolt (mv) drop (heat loss I2R) at metal to carbon joint. It keeps the joint temperature low.
  • It reduces power loss. Therefore, increases input power.
  • It improves rate of heat which results faster and more molten metal production.
  • It reduces cost of production by reducing power loss, carbon loss etc.
  • Coating is neutral in nature, so no effect of any gases on stub surface coated with Thermocoat (SEC-P). Physical dimensions of the stub will not reduce like diameter etc, so there will be no rise in stub resistance (compared to eroded stub).
  • It is environment friendly.

Purpose of Coating

  • The coating applied on stub and carbon anode (Top) surfaces splits into two layers. Layer near the principle surface of the M.S stub and carbon anode forms a monolithic joint on surface which is highly electrically conducting. The outer layer formed by the coating is highly thermal conducting and electrical insulating. Both the layers of the coating play an important role in power and carbon saving process.
  • Inner layer which is completely monolithic with M.S stub picks heat of the stub and increases self temperature. It results in development of low resistance super electrical conducting path which reaches carbon anode surface directly and reduces the millivolt drop.
  • The outer layer of the coating also picks heat from the inner layer of the coating which increases outer layer temperature and make it more electrical insulating and anti-oxidant in nature. The second layer also protects the first layer and makes it more effective to produce a low resistance path for a longer time i.e minimum 30-32 days and does not allow damage or oxidization of stub and carbon anode surface.


  • To measure drop in voltage (millivolt drop) between stub and anode, insert the measuring probes up to the inner layer (electrically conducting layer) of the coating.
  • Do not measure millivolt drop between M.S stub’s outer layer and carbon anode’s outer layer. These two layers are electrical insulating layers.
  • Please remove all scales from the stub surface before applying Thermocoat (SEC-P). Apply coating on clean and unoxidised M.S stub surface to get the best results. Removal of scale is must before application of Thermocoat (SEC-P) on stub/anode surface.
This results in saving of power and carbon. It will reduce production cost by 5-7%.
AEPCO - Bhopal - +91-755 -2766797 | Kolkata - +91-33-22477692 | +91-9830052452 |  

All rights reserved - PATKI'S TECHNOLOGY