| 摘要 |
<p>PURPOSE:To economically treat scrap metal without using org. solvent and to recycle the scrap metal by cleaning the scrap metal stained with oil with an aq. cleaning soln. contg. specified surfactant, phosphate, silicate, etc. CONSTITUTION:A cleaner such as an anionic surfactant, nonionic surfactant, alkaline phosphate and alkaline silicate is added to water to prepare an aq. cleaner. The scrap metal stained with oil is cleaned by using this cleaner. In this case, the cleaner is preferably kept at pH 10 to 11. The cleaner is filtered off after cleaning, and the scrap metal is ultrasonically cleaned in an aq. cleaner having the same concn. as or more dilute than the cleaner. Consequently, the oil depositing on the scrap metal and the additional elements such as zinc, tin, lead, carbon, sulfur and phosphorus contained in the oil are effectively removed. The treatment is also appropriately applied to the scrap metal contg. elements easy to react with carbon and to the scrap metal easy to dissolve carbon.</p> |
