Title: Magnesium Carbonate Hydroxide
CAS Registry Number: 39409-82-0
CAS Name: Carbonic acid, magnesium salt (1:1), mixt. with magnesium hydroxide, hydrate
Trademarks: Marinco C
Literature References: Usually a basic carbonate, approx (MgCO3)4.Mg(OH)2.5H2O; approx mol wt 485; contains 40-42% MgO. Prepn of various hydrates: Pond, Heneghan, US 3169826 (1965 to Merck & Co.). Magnesium carbonate minerals include magnesite and lansfordite.
Properties: White, odorless, bulky powder or light friable masses; at about 700° is converted into MgO. Sol in about 3300 parts CO2-free water; more sol in water contg CO2; sol in dil acids with effervescence. Insol in alcohol. Imparts slight alkaline reaction to water.
Derivative Type: Hydrotalcite
CAS Registry Number: 12304-65-3
Trademarks: Altacite (HMR); Hi-Ti (Kyowa); Nacid (Shionogi); Talcid (Bayer)
Literature References: an aluminum magnesium hydroxide carbonate hydrate of the general formula Al2O3.6MgO.CO2.12H2O. Prepn: Kumuru et al., US 3539306 (1970 to Kyowa).
CAUTION: Potential symptoms of overexposure to magnesite are irritation of eyes, skin, respiratory system; cough. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 188.
Use: Fireproofing, heat insulating; preparing effervescent magnesium citrate; clarifying liqs by filtration; in tooth and face powders, in polishing compds; manuf mineral waters, pigments, paper; filler for rubber.
Therap-Cat: Magnesium carbonate hydroxide as antacid, cathartic; hydrotalcite as antacid.
Keywords: Antacid; Laxative/Cathartic.