The Bridgeport times and evening farmer., 1918-08-09

three pounds per barrel of cement, or to about 60 per cent. of the total potash that nters the kilns. This is now separated by teaching from the rest of the dust with which it is col lected, and is placed on th9 market in the form of a concentrated salt containing about per cent. of pot assium sulphate. At other plants, as the Security Cement 6 Lime Com pany, the potash is not separated from the dust, but the mixture of both is disposed of directly as col lected for use in the manufacture of fertilizers.
 In an investigation recently com pleted in the Bureau of Soils, it was | shown that the potash that escapes from the different cement plants of the country varies from 0.35 to 5.S4 pounds per barrel of cement, with an | average of about 1.9 pounds. Taking 90,00O,000 barrels as the average an- 1 nual production of cement in this
 country, then 1t may be estimated 1 that the total potash escaping from all the cement plants of the country
 as at present operated amounts to about 86,000 tons annually. Assum-
 ing, in the light of results already ob-
 tained, that it would be possible to re-
 cover in availabale form, say 80 per
 cent. of the total escaping, then the
 available potash that would be pos
 stble of recovery in the cement in-
 dustry of this country amounts to
 about 75,000 tons annually
 It has been shown, moreover, that l the amount of potash that escapes from cement plants may be increased by increasing the percentage occur ring in the raw material or by ln- creasing by chemical or other means the percentage of potash volatilized.
 If the same relative increase in the potash volatilized could be effected ir
 all plants as has already been secured
 in some plants where potash is now
 being recovered, then the available
 recoverable potash in the cement
 plant of the country would be in
 creased from 10000 tons to about
 100000 tons annually. Still greater
 possibilities are to be expected by the
 use of feldspar and other potash min
 erals in the raw materials, and it k
 for reasons Juch as these outlined
 that the cement industry is looked
 upon as one of the principal potentia
 sources of potash supply in this coun,
 try.
 Since fertilizers are food for plant.
 it will follow that plants, and particu.
 larly certain parts of plants, may serve as fertilizers for a new crop. A one time a plant waste known as cot l tonseed meal, obtained in the manu = l fa ctI1+Ta Of oOttoncaa5 oil af 7 the largest single source of nftroge | nous material used in fertilizers, anC the quantity still used for this pur | pose is in excess of 3OO,0O0 tons an 5 nually. A case of this kind is seer r in the recovery of potash as a by } product in the manufacture of nico t tine from tobacco waste. This is an ], other illustration of the use as a fer tilizer of a waste product recovered l in the utilization of waste.
 Summing up, it may be stated tha s industrial wastes furnished about 4 8 per cent. of the potash, per cent. o { the phosphoric acid, and S5 per cent I of the nitrogen used in this countr . in 1916.
 : The potash was obtained from sucI 0 wastes as tobacco stems, cottonsee @ hulls, hardwood ashes, wool washing: = blast-furnace flue dust, cement flu
 dust, and sugar residues; the phos e phorio acid was furnished by sue n materials as bones shells, fish scraI e and basic slag; and the nitrogen wa t obtained from wastes in the manufac # ture of castor, linseed, and fish oils $ from animal wastes, as blood, hai e horns, hoofs, and hides; from leathe a and wool wastes; from coke; and fro1 t a long list of other substances.