Chemical Analysis of Building Gypsum(IS 1288 · IS 2547)
Chemical analysis of mineral and building gypsum — purity (CaSO₄·2H₂O), combined water, chlorides and impurities per IS 1288, with building-plaster requirements per IS 2547.
What is Chemical Analysis of Building Gypsum?
Gypsum's performance as plaster, plasterboard feedstock and cement retarder is set by its chemistry: the gypsum purity (CaSO₄·2H₂O content) drives setting behaviour and strength, while chlorides and soluble salts cause efflorescence and corrosion risk in contact with steel. IS 1288:1982 (Methods of Test for Mineral Gypsum) provides the analytical methods; IS 2547 (Gypsum Building Plaster) sets the product requirements for plaster grades.
Global Lab determines purity via combined-water and sulphate routes, free and combined water, chloride content, pH and insoluble residue — serving plaster manufacturers, plasterboard plants, cement works (retarder gypsum QC) and importers verifying consignment quality.
How the Chemical Analysis of Building Gypsum is Conducted
- 1
Sampling & Preparation
Lumps or powder are sampled, dried at the specified low temperature (to preserve hydrate water) and pulverised to analytical fineness. - 2
Combined Water Determination
Hydrate water is driven off at the standard temperature band and gypsum content computed from mass loss. - 3
Sulphate Route Cross-Check
Sulphate (SO₃) is determined gravimetrically and purity cross-computed for confirmation. - 4
Impurity Analysis
Chlorides, insoluble residue, pH and free water are determined per IS 1288 methods. - 5
Reporting
Purity, impurity profile and grade verdicts (per IS 2547 where applicable) are issued via Autovity QLMS.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 1288:1982 | Methods of Test for Mineral Gypsum (Reaffirmed) | Analytical Methods | Indian Standard |
| IS 2547 (Pt 1):1976 | Gypsum Building Plaster — Specification (Reaffirmed) | Plaster Requirements | Indian Standard |
| IS 2095 (Pt 1):2011 | Gypsum Plaster Boards — Plain (Reaffirmed) | Board Product Reference | Indian Standard |