Basic magnesium carbonates

Carbonic acid, magnesium salt (1 1), mixture with magnesium hydroxide (Mg(OH)2), hydrate CCRIS 7884 Magnesium carbonate basic Magnesium carbonate hydroxide Marinco C. A basic magnesium carbonate of variable composition. Used in fireprooSnp, as an antacid and laxative and in manufacture of magnesium compounds. 

Synonyms Basic magnesium carbonate Hydromagnesite Magnesia alba Magnesium carbonate basic Magnesium carbonate basic, heavy... 

Magnesium Carbonate basic, satd. 25 >30 6 Resistant -0.3-2 85-115 Solef Solvay Polymers Specimen Solef 1008, 1010 and 1012, 2 mm thick test pieces... 

Properties. The physical properties of the normal magnesium carbonates are given in Table 3, those of the basic magnesium carbonates in Table 4. Magnesium carbonate is insoluble in C02-free water. The solubiUty products, iC, for magnesium carbonate and some hydrates foUow (38). 

Table 4. Physical Properties of Basic Magnesium Carbonates ...

Normal, hydrated, and the basic magnesium carbonates react with acids to yield salts which can be recovered by crystallization (43). Magnesium carbonate forms many double salts, some of which are Hsted ia Table 5. 

The principal producers of synthetic normal magnesium carbonates and basic magnesium carbonates are J.T. Baker Inc., Philipshiirg, New Jersey GTE Corp., Sylvannia Chemicals Division, Towanda, Peimsylvania Mallinkrodt Specialty Chemicals, St. Louis, Missouri Marine Magnesia, San Erancisco, California Morton Specialty Chemicals, Manistee, Michigan and Ube Chemical Industries, Tokyo. 

Precipitated magnesium carbonate and basic magnesium carbonates are calciaed to produce magaesia having surface areas of ca 200 /g. These... 

USP-grade anhydrous magnesium carbonate is used as a flavor impression intensification vehicle in the processed food industry (see Flavors and spices). Basic magnesium carbonates are used as free flowing agents in the manufacture of table salt, as a hulking agent in powder and tablet pharmaceutical formulations, as an antacid, and in a variety of personal care products (see Pharmaceuticals). 

MgO samples were prepared by heating basic magnesium carbonate for 3 h. CaO samples were made from calcium carbonate pretreated in N2 at 1173 K for 2 h. MgC-A Os samples were prepared by heating hydrotalcite at 823 K for 4 h. 

Recently, the influence of the preparation method of various MgO samples on their catalytic activity in the MPV reaction of cyclohexanone with 2-propanol has been reported 202). The oxides were prepared by various synthetic procedures including calcination of commercially available magnesium hydroxide and magnesium carbonate calcination of magnesium hydroxides obtained from magnesium nitrate and magnesium sulfate sol-gel synthesis and precipitation by decomposition of urea. It was concluded that the efficiency of the catalytic hydrogen transfer process was directly related to the number of basic sites in the solid. Thus, the MgO (MgO-2 sample in Table IV) prepared by hydration and subsequent calcination of a MgO sample that had been obtained from commercially available Mg(OH)2 was the most basic and the most active for the MPV process, and the MgO samples with similar populations of basic sites exhibited similar activities (Table IV). 

Formula MgCOs MW 84.31 several hydrated and basic carbonates are also known that are stable and occur in nature. The types, names, formulas and CAS Registry numbers of anhydrous, hydrated and basic magnesium carbonates are tabulated below ... 

The trihydrate, MgC03 3H20 or other hydrates on heating form basic magnesium carbonates, the product compositions depending on degree of water of crystallization and temperature. 

Mixtures containing potassium chlorate can be quite susceptible to the presence of a variety of chemical species. Acids can have a dramatic effect - the addition of a drop of concentrated sulfuric acid (H 2SO 4) to most KCIO 3 /fuel mixtures results in immediate inflammation of the composition. This dramatic reactivity has been attributed to the formation of chlorine dioxide (ClOj) gas, a powerful oxidizer [5]. The presence of basic "neutralizers" such as magnesium carbonate and sodium bicarbonate in KC10 3 mixtures can greatly lower the sensitivity of these compositions to trace amounts of acidic impurities. 

Hydromagnesite is a basic magnesium carbonate 4MgC03.Mg(0H)2.4H20, while huntite is a mixed calcium magnesium carbonate SMgCOj.CaCOj. Both materials generally exhibit a platy crystal habit. 

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