a metalworking liquid having utility as a recycleable general purpose cutting and grinding coolant contains a major amount of aqueous solution of a block copolymer of ethylene oxide and propylene oxide and having a molecular weight of about 1800 - 2900 , and an amount of both an alkanolamine cinnamate and a boron amine complex effective to inhibit corrosion . also the liquid generally contains a germicide , an anti - foaming agent and a ph control agent . at an elevated temperature said liquid undergoes a phase separation in which most of the foregoing materials do not remain in the contaminated water which then can be discarded . the remaining mixture can be diluted with clean water and reused .