Gypsum Products

Gypsum Products

1. VARIOUS FORMS OF CALCIUM SULFATE, HYDROUS, AND ANHYDROUS

2. CALCINATION OF CALCIUM SULFATE

   • CaSO4-2H20
     • partial dehydration CaSO4 1/2H20 (hemihydrate)

3. Plaster ISO 2

   • wet calcination
   • dense prismatic crystal of hexagonal calcium sulfate

4. High Strength Plaster

   • Stone 3
   • Stone, high strength low expansion 4
     • die stone
   • stone high strength high expansion 5
     • die stone

5. Impression Plaster ISO1

   • hemihydrate plasters by dry calcination
     • powders
       • low apparent density
       • high relative surface area
       • poor packing ability

6. Chemistry

   • 20 Celcius to 700 Celsius
   • medium and high strenth plasters (stones
     • pseudomorphic
       • crystal structure of hemihydrate and hexagonal crystal habit of anydrous calcium sulfate
     • higher apparent denisty and smallar relative surface area than dry calcination
     • water calcination
     • less crystallogrpahic strain and lower surdface FREE energy,, betterpacing abilitt and higher apparent density
   • high strenght
     • crystal habit modifiers
       • producing crysta that are shorter and thicker
     • Densite and Crystacal
   • high adhesion of particles to neighbors
     • high surface free energy
       • hemihyrdtate powders dry calcination