Page:Popular Science Monthly Volume 81.djvu/41

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35
TRINIDAD AND BERMUDEZ ASPHALTS
Bitumen sol. in CS2 99 .9 per cent.
Bitumen insol. in 88° naphtha 8 .3 per cent.
Loss 5 hours 325° F. (20 grams) 24 .6 per cent.
Condition of residue Fluid
Paraffine None
Viscosity—Engler—212° F.—50 c.c. 34 .5 sec.
 

Engler Distillation

Below 302° F 4.43 per cent.
302-520° F 20.74 per cent.
Residue above 520° F 74.53 per cent.
Loss .30 per cent.
———
100.00
 

This petroleum is truly asphaltic and carries no solid or heavy liquid paraffine hydrocarbons. It is distinguished by the fact that it yields a high percentage of light distillates or "tops" for an oil of such low gravity. The intermediate distillates, those of the lubricating type, are small in amount, while the residue is truly asphaltic resembling that found in the lake deposit, but of course free from mineral matter and water. On this account the oil is peculiarly adaptable to road surfacing work, the light oil carrying the heavier asphaltic portion into the surface and afterwards, on its evaporation under the sun, leaving it there in a most desirable form as a binding agent. If the lighter fraction or "tops" are removed, we have at once an asphaltic oil which is of the most desirable character for hot application, and has the following characteristics:

 
Specific gravity at 60° F .994
Beaume at 60° F 10 .8°
Flash—open cup 200 °F.
Bitumen sol. in CS2 99 .9 per cent.
Bitumen insol. in 88° naphtha 10 .8 per cent.
Loss 5 hours 325° F. (20 grams) 17 .5 per cent.
Condition of residue Fluid
Paraffine None
Viscosity—Engler—212° F—50 c.c. 102 .2 sec.
 

The oil is further distinguished by the fact that it carries a very considerable percentage of sulphur, in the neighborhood of 3 per cent, and it is evident that the sulphur found in the Trinidad crude asphalt is derived, at least in part, from this source. Owing to the presence of this sulphur the oil possesses those desirable characteristics, as a road oil, which the refined Trinidad asphalt possesses as a paving material, and it is for this reason that a road carpet prepared with this liquid asphalt does not become unpleasantly soft when exposed to the sun.

 

(To be concluded)