TRINIDAD AND BERMUDEZ ASPHALTS 



29 



The emulsified water can be removed from the crude Trinidad 

 asphalt by grinding it to a fine powder and exposure to the air, or by 

 heating the material to a temperature above the boiling point of water, 

 and until the bitumen melts. Upon the latter fact is based the process 

 of refining which is used industrially, and which will be described 

 later. 



The bitumen of Trinidad asphalt can be separated from the mineral 

 matter by solvents, and thus prepared is a brilliant, glossy, pitchlike 

 substance, which has a semi-conchoidal fracture when struck a sharp 

 blow, but which yields to gentle pressure and slowly flows at summer 

 temperatures. It softens at 76° C, flows quickly at 83° C, but is not 

 liquid until a temperature is reached which is above 100° C. It has a 

 specific gravity, when entirely free from mineral matter, of 1.032 at 

 25° C. 



Its ultimate composition is 



Carbon 82.33 



Hydrogen 10.69 



Sulphur 6.16 



Nitrogen 0.81 



99.99 



It is noticeable that this bitumen is characterized by the large 

 percentage of sulphur which it contains, by the presence of nitrogen, 

 and by the absence of oxygen. 



It is to the sulphur which is present, as will be shown later on, that 

 the valuable properties of the Trinidad bitumen are to be attributed. 



Photo, C. R. Toothaker, Phila. Commercial Museum. 

 Pier with Crude Asphalt in Buckets. 



