Aluminum potassium sulfate
Description
A white odorless powder with transparent crystals. Aluminum potassium sulfate occurs naturally in the minerals alunite and leucite. It has been used since ancient times as a mordant in dyeing textiles and for tawing skins. Aluminum potassium sulfate, or potash alum, is also used as a filler in paper, cement, and paints. It is used to harden gelatin, plaster, and cement. Potash alum has also been used as a substrate in the preparation of lake pigments.
Synonyms and Related Terms
potassium aluminum sulfate; aluminum potassium sulphate (Br.); potash alum; alum NF; potassium alum; kalinite; alum flour; alum meal; cube alum; alumstone
Other Properties
Soluble in water. Insoluble in ethanol.
| Composition | Al2(SO4)3-K2SO4-24H2O |
|---|---|
| CAS | 7784-24-9 |
| Mohs Hardness | 3.5 - 4.0 |
| Melting Point | 92 |
| Density | 1.75 |
| Molecular Weight | mol. wt. = 474.38 |
Hazards and Safety
Noncombustible.
Harmful by ingestion and inhalation. Contact causes irritation.
Mallinckrodt Baker: MSDS
Authority
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 32, 33
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986
- Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
- Palmy Weigle, Ancient Dyes for Modern Weavers, Watson-Guptill Publications, New York, 1974
- Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
- Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
- Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983
- A Glossary of Paper Conservation Terms, Margaret Ellis (ed.), Conservation Center of the Institute of Fine Arts, New York City, 1998