Graphite Electrode
SaTraD® Graphite Electrode – China graphite electrode distributor.

What is graphite electrode?

Graphite electrode is used in electric arc furnace (EAF) and ladle furnace (LF) of a steel mill for steel making, it is a part of the furnace roof structure and serve as a device conduct electricity into an electric arc furnace which generates sufficient heat to melt scrap steel.

The electrodes are assembled into columns. Furnaces using 3-phase AC (alternating current) electricity are 3 electrode columns; DC (direct current) furnaces are use 3 electrodes connected into one column, they are generally larger in diameter. The size of electrodes ranges from 75mm to 750mm in diameter, and 1600mm~2800mm in length. 

The tip of these electrodes can reach up to 3000oC~5000oC, which is approximately half the temperature of the sun. In addition to excellent mechanical strength, thermal expansion, thermal shock resistance and machinability, the high temperature helps in reducing the entire mass of steel. 

Type of Graphite Electrode

• Ultra-high power (UHP)
• High power (HP)
• Regular power (RP)

Corresponding to the power level of electric furnace steelmaking, the graphite electrode are named as Ultra high power graphite electrode (UHP grade), high power graphite electrode (HP grade), regular power graphite electrode ( RP grade).

The technical properties of the high power and Ultra high power graphite electrodes are better than those of regular power graphite electrodes, such as lower resistivity, higher bulk density, higher mechanical strength, and lower linear expansion coefficient, excellent oxidation resistance and so on. 

High power graphite electrodes are used for manufacturing non-ferrous metals and medium-and low-grade steel through electric arc furnace and ladle furnace. It is made up of premium quality of petroleum coke with pitch and 30% needle coke. Regular power graphite electrodes are used for ferroalloy production, silicon metal production and smelting processes. It is made of high quality petroleum coke and pitch. UHP graphite electrodes are used for EAF and Ladle furnace steel making, which made of 100% needle coke and pitch.

Raw Material

Graphite electrode is a kind of high temperature resistant graphite conductive material made of petroleum coke, needle coke, pitch coke, coal tar pitch,etc. 

Technology

Extrusion Machine : 41MN 25MN 15MN 
Ring Baking Furnace : 18,20, 24 rooms Ring Baking Furnace
Impregnation: High pressure impregnation kettle
Graphitization: Acheson DC graphitization furnace
Graphitization: LWG graphitization furnace
Machining: 
Electrode CNC Machine
Double-thread Combing and Milling Machines
Full-automatic CNC Machine for Nipples.

Production Process & Production Cyclce

Normally, the process and corresponding time of the production of a batch of ultra-high power or high-power graphite electrodes are as follows:
• Extrusion Forming (3 days)
• Primary Baking (25 days)
• Impregnation (4 days)
• Secondary baking (15 days)
• Graphitization (10 days)
• Machining / quality inspection (2 days)
• Finished packaging (1 day)

In general, the whole production process without discontinuity, from raw material process to the finished product, need about 60 days at the fastest.The production of the graphite nipple is about 90 days at the fastest because the nipples need two times impregnation and three times baking.
How long does it take to produce HP/UHP graphite electrode?
The graphite electrode has many production processes and a long production cycle. 
The production cycle of ordinary power graphite electrode is about 45 days; 
The production cycle of ultra high power graphite electrode needs more than 75 days; 
The production cycle of graphite nipples is much longer about 90 days.