822 



ANNUAL REPORT OF THE 



Off. Doc. 



it is necessary to use in order to bring the desired change of a tri 

 calcium x^hosphate to the soluble and reverted forms, can be easily 

 calculated. These amounts have been worked out for practice as 

 expressed in the following table: 



TABL.E 6.* 



One Part by Weight of Each Substance Below Requires, 

 Sulphuric Acid by Same Unite of Weight. 



o 



s 



Tri-calcium phosphate, 



Iron phosphate, 



Aluminum phusphate, . 



Calcium carbonate, 



Calcium fluoride, 



Magnesium carbonate, 



1.S52 

 1.390 

 1.721 

 1.411 

 1.794 

 1.660 



•H. W. Wiley's "Principles and Practice of Agricultural Analysis," Vol. II, pp. 155. 



Example. — Suppose, for example, a phosphate of the following 

 composition, is to be treated with sulphuric acid, viz: 



Moisture and organic, 



Calcium phosphate 



Calcium carbonate 



Iron and aluminum phosphate, nearly all A 



Magnesium carbonate 



Calcium fluoride, 



Insoluble, 



Per cent. 



4.00 

 55.00 

 3.00 

 6. BO 

 0.75 

 2.25 

 28.00 



Using sulphuric acid of 50° B., the following quantities will be re 

 quired for 100 kilograms: 



Calcium phosphate, fifty-five kilos, 



Calcium carbonate, three and a half kilos 



Calcium fluoride ,two and a quarter kilos 



Aluminum and Iron phosphate, six and a half kilos, 

 Magnesium carbonate, three-quarters of a kilo, 



Total, 



S. 3 



bS.44 

 6.4S 

 4.52 



12.55 

 1.40 



107.39 



•One kilo— about 2.2 lbs 



