Neutral ramming mass uses corundum and magnesium aluminum spinel as the main aggregates. Featuring strong chemical inertness, it can resist erosion by both acidic and basic molten slags, making it a preferred refractory material for environments with mixed slags. Its typical application scenarios are outlined below.
1. Iron and Steel Smelting Equipment
Ladle bottoms, ladle rims and transition zones at the slag line. Acidic and basic components of steel slag alternate in these areas, and neutral ramming mass prevents insufficient slag resistance against either type of slag. It's also applied for repairing electric furnace roofs, tapping holes and launders to withstand scouring and penetration by molten steel and mixed slags.
2. Non-ferrous Smelting Furnaces
Linings of melting furnaces and holding furnaces for aluminum, copper, zinc and other non-ferrous metals. Composite oxide slags form during smelting. The neutral material avoids low-melting reactions with furnace slags and extends the service life of the lining.
3. High-temperature Equipment Exposed to Mixed Flue Gas
Chemical cracking furnaces, heat-treatment bogie furnaces and flues of waste incinerators. The flue gas contains acidic sulfur oxides together with alkaline metallic dust. Ordinary acidic or basic refractories are vulnerable to dual corrosion, while neutral ramming mass delivers superior adaptability.
4. Other Special High-temperature Service Conditions
Intermittent heating furnaces with frequent temperature fluctuations, non-ferrous metal casting launders and small special alloy melting furnaces. It balances thermal shock resistance and dual anti-slag performance.
Although neutral ramming mass resists mixed acid and basic slags, long-term contact with highly basic concentrated magnesium-calcium slags should be avoided. Compact thoroughly layer by layer during construction and carry out standardized furnace baking to minimize molten slag penetration channels. For high-temperature equipment under mixed acid-base slag and complex flue gas attack, neutral ramming mass makes up for the one-way slag resistance shortcoming of acidic and basic refractories. It suits composite corrosion conditions across industries and reduces equipment maintenance frequency.
