Patented Oct. 11, 1949 PROCESS OF MAKING BINARY ASPHALTIC PARTICLES Gilman B. Mollring, Los Angeles, Calif.
' NoDrawing. Application August 31, 1945,
Serial No. 613,961
4 Claims. (01. 117-21) This invention or discovery relates to a process for transmuting asphalt, bitumen or similar material of a general thermo-plastic nature into a multiplicity of tiny, cold, solid, non-agglomerating binary particles. Each particle of which contains an inner core of relatively low melting point asphalt and an outer capsule-like shell of relatively high melting point asphalt, or asphalt tempering material as hereinafter described.
Applicant is aware that the prior art proposes asphalt in many forms of discrete unitary particles, including powder, granules, filaments and other shapes of separated particles. Difficulty has been experienced in the above mentioned methods in that the product as produced is expensive of manufacture and restricted to the use of a single grade of high melting point asphalt. My process as hereinafter described presents a new method for comminuting asphalt or bitumen and results in the creation of a distinctly new product as will be apparent from the following description of the product, process and claims.
It is an object of this process to produce a multiplicity of tiny, cold, solid, nonagglomerating particles of asphalt each particle of which comprises two distinct but inseparable parts fused together and comprising an inner core of relatively low melting point asphalt and an exterior capsule-like shell of a relatively high melting point asphalt. The inner surface of said capsulelike shell adhering to the exterior surface of the asphaltic core by being fused thereon during the carrying out of the process. The exterior surface of said capsule-like shell is characterized by being substantially non-adherent and liquid solvent soluble at normal temperatures and pressures.
It is a further object of this process to provide asphalt or bitumen in an easily handled form,
preferably in bulk, inexpensive sacks or returnable containers and in a form which will prevent coalescense at the elevated temperatures and pressures experienced in storage or transit.
It is an additional object of this process to provide asphalt or bitumen in a form which will upon liquefaction amalgamate to become a substantially homogeneous composite bituminous binder of a relatively medium melting point suit able for coating aggregate material and the like.
In practicing my process, hot liquid asphalt or bitumen of a relatively low melting point is sprayed or atomized into a continuously moving bed or mass of substantially cool finely-divided asphaltic tempering material having a relatively high melting point; as the hot needle-like streams or sprayed particles of hot liquid asphalt impinge with the cooler powdered asphaltic tempering material, the action of impingement in conjunction with the sudden change of temperature causes the hot liquid asphalt to be transmuted from a hot liquid condition into contracting, cooling discrete particles of solidifying asphalt, and it is during this brief interval of changing from a hot liquid into ,cold solid particles that the thus formed asphaltic particles are covered with a uniform thickness of powdered high melting point asphaltic tempering material which fuses in the same brief interval with the exterior surfaces of the said asphaltic particles to form protective substantially capsule-like shells for the asphaltic particles as they cool and harden.
While I have described the inner core of the asphaltic particle as being composed of a relatively low melting point asphalt, it is apparent that both the core and shell could be composed of the same grade of asphalt or the core could be composed of an asphalt having a higher melting point. For the best results I prefer that the product be made in the order stated.
While I have described the asphaltic shell as being composed of a relatively high melting point asphalt or bituminous tempering material, I mean to include any or all finely pulverized natural rock asphalts or combinations thereof, or it may consist in whole or in part of a pulverized high melting point refined asphalt.
In one modification of my process I have used 50% by weight of a diatomaceous earth to 50% of finely ground high melting point asphalt as my tempering material, and it is apparent that more or less could be added without departing from the spirit of the discovery. It is apparent too that both the core and the shell could be made of a filled asphalt as the term is understood in the industry.
What I claim is:
1. A process of manufacturing separated binary asphaltic particles, which comprises discharging continuous needle-like streams of relatively low melting point hot liquid asphalt into a moving bed of cool finely-divided tempering material comprising solid high melting point asphalt while continuously moving the tempering material away from the point of impingement at such a speed that the liquid asphalt is divided into individual particles which are solidified and coated' with the tempering material.
2. A process of manufacturing separated binary asphaltic particles comprising heating a relatively low melting point asphalt to an elevated temperature above the melting point thereof, spraying the molten asphalt in the form of atomized particles into a bed of cool finely-divided solid tempering material comprising high melting point asphalt, While said bed is continuously moving away from the point of impingement of the hot liquid stream of asphalt at such a speed as will convert the atomized particles into individual substantially spherical-shaped, separated solidparticles coated with thesaid asphaltic tempering material and maintaining the temperatures of the particles and the tempering material such that the tempering material adheres to the exterior surface ofth mdividual particles by fusion thereon to maintainthe particles of asphalt separated.
3. A process of manufacturing binary asphaltie particles comprising heating a relatively high penetration asphalt to an elevated temperature above the melting point thereof, flowing the asphalt as thus heated in needle-like streams into a bed of cooler high melting point pulverized asphalt; which is; moving awayfrom the point-yof impingement, of the streams of hot: liquid asphalt 317151191113 a speed. as will! comminutethe asphaltic liquidl into individual substantially sphericalshaped: particles. of asphalt, and maintaining the temperatures; of the hot liquid asphalt and the cool high melting point pulverized solid asphalt such that the liquid asphalt particles are solidified and the pulverized asphalt is heated sufliciently on contact with the hot liquid asphaltic particles as thus formed to fuse with the exterior surface of the solidified particles to provide capsule-like shells for same.
4. Av process according ta claim 1 in which the tempering material is composed ofapproximately 50% by weight of diatomaceous earth and 50% by weight of finely ground high melting point asphalt.
' GILMAN B. MOLLRING.
REFERENCES CITED The; following references are of record in the file: of this patent:
UNITED STATES PATENTS Number Name- Datev 2,396,910 Zai'sser" Mar. 19, 1946 2,399,717 Arveson May- 7-, 1*946 FOREIGN PATENIS Number Country Date 394,649 Great Britainr933