Key Points for Using Electrode Paste in Silicon-Manganese Alloy Submerged Arc Furnaces and Common Is-FAQ-Graphite Electrode and Electrode Paste Supplier | Rongxing Group-Graphite Electrode and Electrode Paste Supplier

Key Points for Using Electrode Paste in Silicon-Manganese Alloy Submerged Arc Furnaces and Common Issues (2026 Edition)

Abstract

Silicon-manganese alloy (SiMn) is one of the ferroalloy grades with the largest output in China, and it is also the smelting grade with a relatively high unit consumption of electrode paste and the most concentrated electrode accidents. Understanding electrode management of SiMn furnaces is the starting point for mastering the on-site application of electrode paste.

Keywords|Electrode paste, Silicon-manganese alloy, Submerged arc furnace

Last updated: 2026-10-29·Owner: Rongxing Group Technical Team

Content

Why the SiMn Furnace "Consumes" So Much Paste

SiMn smelting is a reduction-smelting process intermediate between the slag-forming and slag-free methods, in which the reductant (coke) in the furnace participates extensively in the reactions. The electrode not only conducts electric current; the carbon at its tip also takes part directly in the reduction of metal oxides, forming "chemical consumption". Industry statistics show that the electrode consumption rate of SiMn furnaces is about 1.2 times that of ordinary ferromanganese furnaces.

Key Points for Use

Paste type selection: Use standard electrode paste or high-strength paste for semi-enclosed furnaces, and sealed paste for closed furnaces. For SiMn furnaces, grades with volatile matter in the upper-middle range (13%–15.5%) and ash content ≤ 4% are recommended, so as to balance sintering speed and strength.

Paste column height: A proper paste column is the key to ensuring electrode strength. The paste column height is recommended to be controlled at 3–3.5 times the electrode diameter. If the column is too high, coarse and fine particles will segregate; if it is too low, the column pressure will be insufficient and the packing will not be dense, resulting in a porous electrode that breaks easily. The paste column height should be adapted to the furnace conditions under different ambient temperatures and production situations.

Example: As of October 22, 2026, paste suspension had already occurred in the Inner Mongolia region when the column was raised to 3.5 m, whereas in the Guangxi region even 5 m caused no problem; the lower the paste column, the lower the strength.

Current density and slipping rhythm: The working current density of self-baking (Söderberg) electrodes is generally 4.5–10 A/cm². SiMn furnaces should operate at a lower voltage and a higher current to reduce side oxidation of the electrodes; slipping should follow the "small amount, many times" principle, to avoid a single overly long slip disturbing the sintering zone.

Common Issues and Treatment

Problem	Typical symptom	Causes (in order of priority)	Treatment
Electrode soft break	The electrode below the copper contact clamps softens, bends and breaks, and paste flows out	① Slipping too fast so that sintering cannot keep up; ② Volatile matter too high and softening point too high; ③ Main factor: mismatch between the electrode paste specifications and the furnace	Cut off power immediately and cool with full air flow; after the fracture is reset, clamp the copper clamps and restore power slowly; reduce the load below 30% and then recover step by step
Electrode hard break	Transverse fracture of the already-sintered section with a flat fracture surface	① High ash content and insufficient strength; ② Segregation of coarse and fine particles; ③ Rapid cooling and heating after a hot shutdown	Remove the broken end and roast it by "dead-phase" baking for about 6 h; or let the broken end "sit" in the furnace burden and be consumed gradually; insulate the exposed section during shutdown
Paste suspension	The paste column height does not drop for a long time and the electrode becomes an "empty shell"	① Softening point too high; ② Unreasonable paste column height	Tap the electrode or poke the paste down with a steel bar
Abnormal electrode consumption	Daily slipping amount is significantly higher than that of similar furnaces	Main cause: the electrode paste specifications do not match	Analyze the ash content and electrical resistivity; select electrode paste specifications suitable for the furnace
Uneven (eccentric) electrode burning	Severe side erosion of a single-phase electrode	Unbalanced three-phase current and inclined burden surface; the cylinder clamp being too tight or too loose; the position of the flue and the designed height of the flue	Keep the three-phase load relatively balanced; level the burden surface; regularly check the equipment that relatively affects the sintering speed