In 2003, Ergon, Inc. received a patent for an accelerator gel additive for use in the production of polymer modified asphalt. Ergon was looking to improve the method for introducing sulfur to the process of producing polymer modified asphalt.
The process of introducing finely divided dry materials, such as sulfur, into reaction vessels or tanks presents an explosion hazard due to the formation and presence of hydrocarbon vapors in combination with elevated processing temperatures. In addition, finely divided dry materials often do not mix thoroughly and efficiently when combined with the liquid material in the system. In an attempt to remedy this problem, the finely divided dry material may be pre-dispersed in oil. However, the tendency for the heavier finely divided dry material to settle requires constant agitation.
More viscous oils and/or asphalt fluxes have been utilized to prevent settlement of the finely divided material, but use of these materials requires application of higher processing temperatures to maintain the oil and or asphalt fluxes at pumpable viscosities. In addition, this method requires constant agitation to maintain dispersion of the finely divided material. As a result, higher temperatures needed in processing increase risks of emission of toxic gases, such as hydrogen sulfide, which is highly toxic and flammable. There are also serious corrosion issues associated with molten sulfur.
Ergon is now offering a product we call BGA, which provides a stable composition for delivering sulfur into the liquid polymer asphalt mixture during the production of polymer modified asphalt. BGA will not separate during storage or during manufacturing processes incorporating its use. BGA is pumpable at ambient temperatures making it easy and safe to handle.