5660. Magnesium Carbonate Hydroxide

Nomenclature

CAS number: 39409-82-0
Carbonic acid, magnesium salt (1:1), mixt. with magnesium hydroxide, hydrate; Marinco C.

Description and 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

Hydrotalcite.

Nomenclature

CAS number: 12304-65-3
Altacite (HMR); Hi-Ti (Kyowa); Nacid (Shionogi); Talcid (Bayer).

Description and 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.

Therapeutic Category

Magnesium carbonate hydroxide as antacid, cathartic; hydrotalcite as antacid.

Therapeutic Category (Veterinary)

Laxative.

Keywords

Antacid; Laxative/Cathartic