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Recovery of Metal Working Fluids Using Chelation-Ultrafiltration Process |
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| Authors: | Brian E Reed Ronald Vaughan Wei Lin Roger C Viadero |
| Affiliation: | 1Member, ASCE
21Assoc. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Missouri-Columbia, Columbia, MO 65211-2200. 32PhD Candidate, Dept. of Civ. and Envir. Engrg., Univ. of Missouri-Columbia, Columbia, MO. 43Asst. Prof., Dept. of Civ. Engrg., North Dakota State Univ., Fargo, ND 58102-1890. 54Asst. Prof., Dept. of Civ. and Envir. Engrg., West Virginia Univ., Morgantown, WV 26506-6103. |
| Abstract: | Metal working (MW) fluids are used to control friction and temperature, improve workpiece surface quality, and reduce tool wear. The batch-life of the MW fluid investigated was controlled primarily by the concentration of metallic soaps (complexes between the oil emulsifier and Al∕Mg. Ethylenediaminetetraacetic acid, a strong metal chelator, was added to the MW fluid to break the oil-Al∕Mg complexes. The aqueous-phase ethylenediaminetetraacetic acid-Al∕Mg complexes were then separated from the oil phase by ultrafiltration (UF). Al levels were reduced between 39 and 49%, and Mg levels were reduced between 67 and 77%. Al transfer from the oil phase to the aqueous phase was slow and increased during UF concentration. Rinsing the concentrated MW fluid with deionized water decreased the ash content but had a lesser impact on Al∕Mg removal. Al mass balances produced errors of 2.8% for run 3 and 6.2% for run 4. The UF system (0.11-μm ceramic membrane) effectively separated the oil and aqueous phases. Permeate turbidity was generally <1 nephelometric turbidity unit and permeate flux ranged from 390 to 220 L∕m2-h (230 to 130 gal.∕ft2-day) depending on the degree of concentration. |
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