| 摘要 |
Metal contaminants are removed from used lubricating oils in a two stage, low temperature batch mode process. The oil is sufficiently hydrated to prevent subsequent crystallization of a first reagent salt solution; the low temperature primary reaction is with an ammonium based salt, or its requisite acid and base to form the salt in-situ, in the range of stoichiometric to multiples of stoichiometric, based upon the quantum of metals present in the oil batch. The hydrated mixture is stirred sufficiently to react the metals present with the salt, then cooled, and any sludge present is removed. The residual oil is reheated, rehydrated if necessary, and a secondary sequestering agent selected from the group comprising water soluble salts of ethylenediaminetetraacetic acid (EDTA), n-hexylamine, ethylenediamine, water-soluble salts of tartaric acid, and alkylbenzene-sulfonic acids, and compatible mixtures thereof is added to complex any remaining metallic compounds. The water is then evaporated and the sludge and crystals removed.
|
