| 摘要 |
<p>Naphthenates of metals which are less basic than an alkaline earth metal, which term includes magnesium, are prepared by contacting an aqueous medium containing at least one such metal value with a solution of an alkaline earth metal naphthenate in an inert solvent which is substantially immiscible with the aqueous medium. The solvent may be an aromatic hydrocarbon or a mixture of an aliphatic hydrocarbon with up to 10% of an aromatic hydrocarbon. The alkaline earth metal naphthenate may be prepared as described in Specification 915,428. Preferably magnesium oxide dissolved in ammonium chloride solution is used in the preparation of magnesium naphthenate. Alternatively, the alkaline earth metal naphthenate is prepared by double decomposition of an alkaline earth metal salt with sodium naphthenate and extracting the alkaline earth metal naphthenate into the inert solvent. The metal forming the relatively more stable naphthenate may be selectively extracted from a mixture by using the amount of alkaline earth metal naphthenate equivalent thereto, e.g. copper may be separated from cobalt, nickel, cadmium, lead, zinc and/or tin. In a continuous process, the naphthenic acid remaining in the organic phase when the metal naphthenate extract is treated with mineral acid solution to recover the metal values (see Division C1) is treated with fresh alkaline earth metal base to reform the alkaline earth metal naphthenate.ALSO:Metal values are extracted from an aqueous medium containing at least one such value, the metal being less basic than an alkaline earth metal, by contacting the aqueous medium with a solution of an alkaline earth metal naphthenate in an inert solvent which is substantially immiscible with the aqueous medium. The term alkaline earth metal includes magnesium. The solvent may be an aromatic hydrocarbon or a mixture of an aliphatic hydrocarbon with up to 10% of an aromatic hydrocarbon, e.g. kerosene. The metal forming the relatively more stable naphthenate may be selectively extracted from a mixture of metal values by using the stoichiometric amount of alkaline earth metal naphthenate, and the method may be used to separate copper from cobalt, nickel, cadmium, lead, zinc and/or tin. Copper and nickel may be extracted separately by extracting first the copper values using the stoichiometric amount of naphthenate corresponding thereto and secondly using naphthenate equivalent to the nickel values. The metal naphthenate extract may be treated with a mineral acid solution to recover the metal values in the aqueous phase, and the organic phase containing naphthenic acid recycled to prepare more alkaline earth metal naphthenate (see Division C2).</p> |
