
TERRA ALBA NO1
Hydrous Calcium Sulfate
The dihydrate form of calcium sulfate is used in low-temperature thermoset plastic and specialty cement applications. Often used as a flame-retarding filler when processed at room temperature. Terra Alba No. 1 is a dihydrate form of calcium sulfate produced by fine grinding and air-separating high-purity, white gypsum containing 20% water of crystallization. It releases combined water as it is heated above 50°C, releasing 75% of water as temperatures reach 180°C (only when temperatures exceed 400°C is water totally removed).
FEATURES & BENEFITS
- Can be used as a flame-retarding filler when processed at room temperature
- Contributes to desired expansion, green strength and controlled set in specialty cement applications
- Is a relatively soft material (2-3 Mohs scale hardness) contributing to minimal wear on equipment.
STORAGE & USE:
When properly used, USG Terra Alba No. 1 Calcium Sulfate Dihydrate Filler is easy to work with. Keep indoors at temperatures between 65 °F – 75 °F (18 °C – 24 °C) and 45% – 55% RH. Do not stack more than two pallets high. Keep from drafts. Rotate stock. USG Terra Alba No. 1 Calcium Sulfate Dihydrate Filler should be used within one year of the manufacturing date located on the package. Always follow handling and use directions and safety warnings on the package. USG Terra Alba No. 1 Calcium Sulfate Dihydrate Filler is not approved for use in food and pharmaceutical applications.
- Specific Gravity 2.3
- pH—10% Slurry 7.3
- Mohs Hardness(1) 2-3
- Refractive Index(1) 1.5
- Oil Absorption(2) 23-25
- Loose Bulk Density (lbs./ft.3)42
- Packed Bulk Density (lbs./ft.3) 62
- L, a, b values(3) 88.0, 0.8, 4.3
- Median Particle Size (microns)(4) 13.0
- Top Particle Size (microns) 150





