How Does Electrode Paste Differ for Yellow Phosphorus Furnaces, Corundum Furnaces and Industrial Sil-FAQ-Graphite Electrode and Electrode Paste Supplier | Rongxing Group-Graphite Electrode and Electrode Paste Supplier

Abstract

First, let us correct a common misunderstanding: these three types of furnaces basically do not use electrode paste. They are precisely the typical cases in which "self-baking electrodes cannot be used" — the problem lies not in the size of the furnace but in the extreme sensitivity of the product to carbon and iron.

Keywords

Electrode paste application boundary；self-baking electrode；iron pickup from the electrode shell；carbon pickup from paste ash；carbon electrode；graphite electrode；industrial silicon grades (553 / 441 / 3303)；corundum alumina purity ≥ 99%；carbon-free requirement for yellow phosphorus；carbon vs graphite electrode selection；electrode oxidation thinning and breakage；open vs sealed submerged arc furnace

Last updated: 2026-11-04 Owner: Rongxing Group Technical Team

1. Why self-baking electrodes cannot be used

Self-baking electrodes have two "inherent defects":

① the electrode shell (steel cylinder) moves downward with the electrode and gradually melts into the furnace, bringing in iron;

② the ash in the paste and the carbon material itself enter the product, bringing in carbon and impurities. For products such as ferrosilicon and calcium carbide this does no harm, but for the following products it is fatal.

Furnace type	Product purity pain point	Consequence of iron / carbon pickup	Actual electrode solution
Industrial silicon furnace	Requires extremely low Fe, Al and Ca (grades such as 553, 441 and 3303 have strict classification limits for iron)	Iron above the limit directly downgrades or even scraps the product	Carbon electrodes, about 70%; the rest are graphite electrodes
Yellow phosphorus furnace	Requires no carbon pickup and low ash, so as not to affect phosphorus purity and downstream processing	Carbon entering the burden disturbs the reduction balance	Mainly graphite electrodes (sealed furnaces)
Corundum furnace	Extremely high alumina purity requirement (≥ 99%); iron and carbon are both harmful impurities	Coloration, affecting refractory / abrasive performance	Carbon or graphite electrodes (refining furnace)

2. The essential differences among the three types of electrodes

Type	Raw materials and process	Graphitization	Price level	Maximum size	Typical applications
Electrode (electrode paste)	Anthracite, coke, graphite fines + pitch, baked in the customer's furnace	No	CNY 3,000–5,000/t	Large diameters possible	Ferroalloys, calcium carbide, ferronickel
Carbon electrode	Electrically calcined coal, petroleum coke + pitch, formed and then baked (about 30 days)	No	CNY 7,000–15,000/t	φ1400 mm	Industrial silicon (mainstream), yellow phosphorus, corundum, special alloys
Graphite electrode	Petroleum coke, needle coke, graphitized at 2,000–3,000 °C	Yes (consumes 4,000+ kWh/t)	CNY 12,500–40,000/t	Normally ≤ φ700–800 mm	Yellow phosphorus (mainstream), small-capacity industrial silicon, refining furnaces

3. Operating differences among the three furnace types

Dimension	Industrial silicon furnace	Yellow phosphorus furnace	Corundum furnace
Furnace type	Open submerged arc furnace	Sealed submerged arc electric furnace	Refining furnace / electric arc furnace
Electrode form	Mainly carbon electrodes, can be continuously extended	Graphite electrodes, requiring periodic replacement	Graphite / carbon electrodes
Electrode consumption	Mainly oxidation and sublimation	Mainly oxidation	Mainly oxidation and breakage
Key control	Electrode insertion depth, burden surface permeability	Electrode sealing, moisture prevention and oxidation prevention	Arc stability, prevention of electrode breakage
Common faults	Electrode thins through oxidation; electrode breakage	Loose or broken electrode joints	Electrode breakage; block loss contaminating the melt