"What are the safety measures for the disposal of cutting oil? Is it possible to process and reuse it?"
In general, cutting oils can be reused several times and are typically designed for this purpose once processed through reclamation equipment. This is also the case with many other types of lubricants such as hydraulic fluids.
Reclamation is necessary with cutting fluids because they can degrade after a period of use due to the working and environmental contaminants to which they are exposed. Even slight mixtures of cutting fluids with other types of fluids and oils will cause them to degrade.
A number of methods and equipment are available for the recycling of cutting fluids, including skimmers, coalescers, centrifuges, settling tanks, magnetic separators and filtration systems.
Skimmers are used to remove tramp oil, which is a contaminated portion of the cutting fluid. The tramp oil floats to the top and is pushed off using a collection belt.
Coalescers and centrifuges can also remove tramp oil as well as solid contaminants. Coalescers promote the fusing together of the tramp oil into larger droplets, which will then naturally rise to the top of the surface more rapidly to be skimmed off. Centrifuges spin the fluid to generate gravitational forces and help separate solids and tramp oil from the normal cutting fluid.
Settling tanks, magnetic separators and filtration systems can remove solid contaminants to varying degrees and efficiencies. Magnetic separators are effective for extracting ferrous particles, while settling tanks are ideal for collecting larger and heavier particles that readily fall to the bottom. Filtration systems trap solid contaminants as the fluid passes through filter media.
After several uses and reclamation cycles, eventually the cutting fluid is destined for disposal. When that time comes, disposing of the fluid must be done with care. Although environmental regulations can be tedious to follow, they are very important.
Tests must be conducted to determine whether the cutting fluid is non-hazardous. This will depend on the fluid’s properties, including its ignitability, corrosivity, reactivity and toxicity. Disposal of non-hazardous fluid may be fairly simple and inexpensive. If the fluid is deemed hazardous, it may need to be taken to a treatment facility.
The U.S. Environmental Protection Agency (EPA) has strict guidelines for a hazardous waste, including its treatment, storage and disposal. Always be sure to check your local regulations and facility’s policies as well.