renovation of used oils with carbon and activated alumina

In many types of plant and machinery the lubricating systems in use make possible the recovery of the used oil in bulk, and when desired this oil may be treated, or renovated, and put back into use. It is not suggested that it is possible by any method of renovation to convert a used oil to its original state of purity and physical and chemical characteristics. It is, however, relatively simple to improve a used oil to such an extent that it becomes again a useful lubricant, if not for the same purpose wherein it has already been employed.