Industrial Uses Of Phosphates PAUL LQGUE
Director, Phosphate Division, Monsanto Chemical Company, S t . Louis, Missouri THE active participation of phosphorus in World War I1 has done more than a whole library of books to create in the common man an awareness of this element. Although i t has always been a part of his body and is essential to his nourishment and well being, he has never before become so conscious of its potentialities for good or evil. Phosphorus, bearer of light, was reputedly discovered accidentally in 1669 by Hennig Brand, an impoverished Geman merchant, who sought to restore his wealth by c o n d n g base metals into gold. Could he have visualized the tremendous significance of his discovery, he would hardly have been willing to dispose of i t as he did for 200 thalen, far its tremendous utility is modem life makes it one of the most valued elements in our chemical storehouse. Fertilizers are the oldest application of phosphorus and continue to reoresent the largest - tonnaee. - . but in the socalled refined phosphorus salts, virtually a new chemical industry has been brought into being. Phosphorus produced in its elemental form from phosphatebearing ore is the mother element of this new industry and growing family of phosphates. Today most of the food-grade phosphoric acids and phosphates, other than those used for fertilizers, are produced by processors of elemental phosphorus from electric furnace operations. Huge electric furnaces feed power through carbon electrodes. tearinz...ohomhorus free from the molecules in . which it is held and extracting it io substmtially pure f#,rrn. I'rorn phocphorus burned in air corner phusphoric acid, and from this versntilc compound arc derived the modern phosphates which reach into almost every basic industry. Widely varied are the uses of phosphates in food manufacture and in the preparation of foodstu5s. In sugar refining, for instance, phosphoric acid is employed in conjunction with lime as a clarifying agent of raw sugar syrup, which contains albuminous and other protein matter. When lime and phosphoric acid are added, they react to form calcium phosphate which precipitates out, carrying with it the protein impurities. In gelatin, phosphoric acid is added as a refining agent, and in jellies it functions in controlling the jelling action through maintenance of the pH a t the required level. In jellies, as well as in soft drinks, phosphoric acid is an acidulant to replace fruit acids, such ascitric or tartaric. Of daily increasing significance in the foodstu5s preparation are moncxalcium phosphate and sodium acid pyrophosphate, act~
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ing as acid leavening agents in the leavening of self-rising flour, cakes, biscuits, and bakery sweet goods. Both chemicals release carbon dioxide from baking soda. The residual salts left after the leavening function is complete, in turn, serve as nutrient elements in bodv nourishment. As each adult contains -in -~.. hi. system approximately 1.4 pounds of phosphorus, he requires a continual replenishing supply. Both tetra-sodium pyrophosphate and di-sodium phosphate are used as small additions in dairy products and have done much to make possible the fast growing packaged cheese industry. Packaged cheese must be made from natural cheeses whose characteristics vary widely. Such cheeses sometimes tend to give 05their fat, and, as a result, globules of oil f o m on their surfaces. Emulsifying agents such as tetra-sodium pyraphasphate and di-sodium phosphate are used to prevent this so-called "oiline" off." Di-sodium phosphate is also used in the adjustment of calcium phosphorus ratios in prepared milk and ice cream. Its action is as an emulsfier, tending to prevent agglomeration of solids, and insures a smooth, creamy consistency. To fortify foodstu5s. such as flour, ferric phosphate provides a rich source of iron. This compound is stable, o5ering no deleterious effect on the oroduct with which it is associated. TriLdrinm ~~phosphlte hnc long Iwcn used as an anti-caking agent in salt. sugar, and orher grar~ularproducts. Indirectly, phosphorir acid makes s contradiction to nature in its use as an ensiling agent t o keep green fodder crops green. Through its use, it is possible to preserve green crops in silos with a minimum loss in nutritional value, thus affording a palatablemidwinter salad for the bovinemilk producer. Related to the uses of phosphates as diet supplements are'the time-honored uses of phosphates in medicinals and pharmaceuticals. The first commercially manufactured phosphate salt was di-sodium phosphate. The same compound is used today as an ingredient of saline laxatives o5ered under various trade names. Because of its value in dentifricesas a polishing agent, di-calcium phosphate is of special interest. Tri-cslcium phosphate and insoluble sodium mela-phosphate are employed for similar purposes. Effective polishing agents, they do not cause wear on the tooth enamel. In addition, di-calcium phosphate serves as a source of calcium and phosphorus, correcting these deficiencies in human nutrition.-Reprinted from Food Materials and Epuifimen1 (April, 1946). ~~
