48 Refining Used Lubricating Oils
amount of friction that will be encountered between sliding surfaces and whether a
thick enough lm can be built up to avoid wear from solid-to-solid contact.
There is no single formulation that can satisfy all the requirements of a solid
lubricant or grease on a cost-effective basis. Properties that should be considered are
coefcient of friction, load-carrying capacity, corrosion resistance (susceptibility to
galvanic corrosion), and electrical conductivity. Furthermore, one must consider the
environment in which the solid-lm lubricant or grease must perform. Such materi-
als must be anticipated to be contained (inadvertently or advertently) in the same
disposal pot as used lubricating oil and therefore conta ...