Refractory ramming mass is a type of refractory material applied by ramming (mechanical or manual). It possesses high density, high strength, and excellent erosion resistance, and is commonly used for linings or filling parts of high-temperature equipment (such as the bottom of induction furnaces, tapping troughs of blast furnaces, and hot spots of electric furnaces). The following is a detailed construction process and key points:
I. Preparations Before Applying Refractory Rammer Mixant
Material Inspection: Confirm the rammer mix brand, shelf life, and absence of lumps.
Check the compatibility of the binder (e.g., resin, phosphate, etc.).
Substrate Treatment: Remove rust, oil, and residual refractory material from the substrate surface, ensuring no loose particles remain.
Pre-embed anchors (e.g., Y-shaped anchors) or weld wire mesh (a bitumen buffer layer is required to prevent expansion stress).
Environmental Control: The construction temperature should be between 5~35℃, humidity ≤70%, and outdoor work should be avoided in rainy or snowy weather.
II. Mixing and Stirring
Dry Mixing: Stir the dry ramming mix for 1-2 minutes until homogeneous.
Adding Binder: Add the liquid binder (such as resin or water glass) according to the specified ratio, and stir for 3-5 minutes until no dry powder remains.
Key Point: Control the amount of liquid added (usually 5-8%). Too little will result in poor adhesion, while too much will cause it to flow.
III. Tamping Construction Process
1. Layered Filling
Each layer thickness ≤ 50mm (excessive thickness can lead to insufficient compaction).
Tamp immediately after filling to prevent initial setting of the material.
2. Tamping Methods
* Manual Tamping: Use a rubber mallet or pneumatic hammer to tamp evenly point by point until the surface is smooth and free of air bubbles.
Suitable for small areas or complex areas (such as steel tapholes).
* Mechanical Tamping: Use a pneumatic tamping machine (frequency ≥ 2000 times/minute), advancing along a "spiral" or "zigzag" path.
High efficiency, suitable for furnace bottoms and large-area linings (such as blast furnace iron troughs).
3. Joint Treatment
The layers need to be roughened (grooves 3-5mm deep) to enhance interlayer bonding.
When construction is interrupted, cover with plastic film to prevent dehydration.
III. Tamping Construction Process
1. Layered Filling
Each layer thickness ≤ 50mm (excessive thickness can lead to insufficient compaction).
Tamp immediately after filling to prevent initial setting of the material.
2. Tamping Methods
* Manual Tamping: Use a rubber mallet or pneumatic hammer to tamp evenly point by point until the surface is smooth and free of air bubbles.
Suitable for small areas or complex areas (such as steel tapholes).
* Mechanical Tamping: Use a pneumatic tamping machine (frequency ≥ 2000 times/minute), advancing along a "spiral" or "zigzag" path.
High efficiency, suitable for furnace bottoms and large-area linings (such as blast furnace iron troughs).
3. Joint Treatment
The layers need to be roughened (grooves 3-5mm deep) to enhance interlayer bonding.
When construction is interrupted, cover with plastic film to prevent dehydration.