Magnesium carbonate. alkalizer

The presence of transition metal compounds as oxidation catalysts can cause rapid degradation of calcium carbonate-alkalized papers under humid conditions. Magnesium carbonate offers better protection than calcium carbonate. 

Paper may be deacidified to make it more permanent. Since the paper often has become brittle before it is treated, methods are needed for increasing folding endurance that may be applied in conjunction with deacidification. In this study, the effects of sorbitol and Hercules Kymene 557H on the folding endurance of three papers alkalized with magnesium carbonate are explored. A synergistic action of the reagents is apparent. 

A variety of adverse effects have been reported following the use of antacids. If sodium bicarbonate is absorbed, it can cause systemic alkalization and sodium overload. Calcium carbonate may induce hypercalcemia and a rebound increase in gastric secretion secondary to the elevation in circulating calcium levels. Magnesium hydroxide may produce osmotic diarrhea, and the excessive absorption of Mg++ in patients with renal failure may result in central nervous system toxicity. Aluminum hydroxide is associated with constipation serum phosphate levels also may become depressed because of phosphate binding within the gut. The use of antacids in general may interfere with the absorption of a number of antibiotics and other medications. 

The various support materials have different effects on potential carbon formation. This seems to go in parallel with the Lewis/Bronsted acidity. The main commercially used catalyst supports can be ranked as follows in decreasing order of carbon forming tendency (and thus in decreasing order of the important minimum practical steam/ carbon ratio) a-alumina > magnesium aluminate (spinel) > calcium aluminate > alkalized calcium aluminate [419],... 

Currently, most cocoa powders are produced by the so-called Dutch or alkalized process, in which the nib is treated with a warm aqueous solution of up to three parts of anhydrous potassium carbonate to 100 parts of nib (or equivalent amounts of other alkalis such as potassium bicarbonate and hydroxide carbonates, bicarbonates, and hydroxides of sodium, magnesium, and ammonium or their combinations). After the alkali is completely absorbed, the nib is processed as in the above method to yield alkalized cocoa powder. Alkalized cocoa is considered to have improved dispersibility, color, and flavor over unalkalized cocoa. 

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