126 CHEMICAL MANUEES. 



— The object of the new process is to divide superphosphates, so as 

 to facihtate their distribution in the soil, for, in the state of lumps, 

 they only give up their phosphoric acid slowly and difficultly. 

 Besides, the fine division of a superphosphate is indispensable 

 from the point of view of the actual manner of distributing manures 

 by the manure drill, which greatly facilitates the work of the 

 farmer. The superphosphate, such as it comes from the mixing 

 " den," contains about 15 per cent of water, and in that condition it 

 is very sensitive to shocks and crushing, so much so, that the 

 processes used to pulverize it up to now are unsuitable. The new 

 process is based on this observation, that hot solid superphosphate 

 such as it exists in the mixing " den," possesses a property which has 

 not been hitherto recognized, that of being capable of being cut into 

 very fine slices, which exposed to the air break up and fall to powder. 

 The process of which the present patent is the object, consists pre- 

 •cisely in cutting the mass in very fine slices in the condition in 

 which it comes from the mixing " den ". Practically that is done as 

 follows : the superphosphate is run into a drum in which knives, 

 animated by a very rapid motion, cut (scrape) the superphosphate 

 -so as to divide it without crushing it. The thin slices are then 

 reduced to a fine powder, the tenuity of which facilitates the ex- 

 pulsion of the. moisture contained therein. The product thus ob- 

 tained can be very easily and uniformly distributed. 



German Patent No. 96,046 of 16 March, 1897. Addition to 

 patent 95,756 of 16 March, 1897, delivered 19 March, 1897, maxima 

 •duration, 15 March, 1912. — The process of which this patent is the 

 subject, is a form of application of a process claimed in chief patent, 

 above-mentioned, the object of which is to cut up fresh superphosphate 

 in a rotary drum armed w^th knives. Up to now the superphos- 

 phate from the " den " was stored, and as soon as it was cold and 

 dry, it was pulverized in a crusher. As it comes from the " den " 

 the superphosphate is hot and soft, on cooling it becomes consistent. 

 It has been remarked that only the superphosphate which comes 

 from the den in lumps becomes consistent, whilst the portions that 

 are in a pulverulent state do not agglutinate but remain in the 

 condition of powder in spite of the pressure of the mass and the 

 high temperature. This observation has suggested the idea, that 

 superphosphate could be reduced to a dry and pulverulent condition 

 as soon as it comes from the mixing " den ". The crushing process 

 used hitherto, such as passage through a Carr's disintegrator, cannot 

 be applied to fresh superphosphate because they would render it 

 gluey. The present invention enables the desired state of division 

 to be imparted to superphosphate immediately it comes from the 

 mixing "den" without grinding or crushing it. The process em- 

 ployed for the purpose is based on this fact, that if superphosphate 

 is cut into very fine slices in its actual condition it is immediately 



