Patent ID: 6932855

Claim:
A method for recycling metals from swarf comprising the steps of: (1) providing a plurality of particles of said swarf having an oil adhering to said swarf as a surface layer; (2) shattering said swarf to have a particulate size ranging from 1 micron to 10 microns; (3) washing said swarf at least once in a washing tank by combining said swarf with an alkaline washing solution having a pH ranging from 10.5 to 11.5 to provide a mixture of swarf and said alkaline washing solution, said alkaline washing solution comprising: (a) an aqueous alkali non-ionic surfactant that further comprises: at least one polyethoxylated alkyl ether containing at least one hydrophobic alkyl ether chosen from the group of alkyl ethers having the formula C n H 2n+1 (C 6 H 4 )(C 2 H 4 O) m where n is an integer chosen from the group consisting of 8 and 9, and m is another integer from 7 to 12, as well as at least one hydrophilic alkyl ether chosen from the group of alkyl ethers having the formula (C n H 2n+1 )O(C 2 H 4 O) m where n is an integer from 11 to 15 and m is another integer from 7 to 12; (b) at least one builder species chosen from the group consisting of sodium silicate, sodium tripolyphosphate and sodium carbonate and combinations thereof; and, (c) a predetermined amount of water, said aqueous alkali non-ionic surfactant further comprising at least one polyethoxylated alkyl species; (4) separating a washed solid from said mixture of swarf and said alkaline washing solution to yield a substantially particulate-free washing solution, said washed solid comprising at least one reclaimable metal for recycling; (5) drying said washed solid and removing said dried washed solid for recycling; (6) separating said oil from the substantially particulate-free washing solution by removing the oil floating above an aqueous phase of the alkaline washing solution to yield a substantially oil-free substantially particulate-free washing solution; and, (7) storing said substantially oil-free substantially particulate-free washing solution.