JPS6318654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Bimetallic salts and their derivatives are useful as scavengers or complexing agents for various liquids such as olefins, aromatics, carbon monoxide, etc. 3,592,865; 3647843; 3651159; 3754047;
Listed in 3755487. The most common bimetallic salt is cuprous aluminum tetrahalide (CuAlX ₄ ), which is generally prepared by reacting cuprous halide with aluminum trihalide in a suitable solvent.

When these complexing agents are used for a long period of time, especially when the feedstock contains olefins and the solvent is an aromatic solution such as toluene, these complexing agents are degraded by alkylated aromatics. be contaminated. That is, the aromatic solvent is alkylated by reaction with the olefin, changing its boiling point and reducing the efficiency of the regeneration process. Spent complexing agent solutions also contain cuprous halide, often in the form of _CuAl The treatment of chemical agents has become a problem. No method has been discovered to remove copper from spent complexing agent solutions.

The present invention relates to a method for removing copper from a spent cuprous aluminum tetrahalide complexing agent solution, comprising the steps of: (1) dissolving the spent solution into a solution of at least 0.5 parts by weight of the solution; , preferably from about 0.5 to about 3, most preferably from about 0.95 to about 1.05 parts by weight of water, thereby forming a solid precipitate of cuprous halide, an organic phase and an aqueous phase; The mixture of 1) is contacted with a suitable amount of a suitable oxidizing agent for a sufficient time to convert the water-insoluble cuprous halide to water-soluble cupric halide, with stirring, and the organic and aqueous phases are separated. or (2b) separating the organic and aqueous phases and removing the insoluble first phase;
The aqueous phase containing the copper halide is treated with a suitable amount of a suitable oxidizing agent and a water-insoluble first phase with stirring.
(3) contacting the copper halide for a sufficient time to convert the copper halide to water-soluble cupric halide; contact with metal, thereby precipitating metallic copper; and (4) recovering the precipitated metallic copper by a suitable method.

Particularly suitable cuprous aluminum halide solution complexes which can be treated by the method of the invention are, for example, chlorides, bromides and iodides, preferably chlorides. Particularly suitable solvents are aromatic solvents such as benzene, toluene, xylene, ethylbenzene and mixtures thereof, preferably toluene.

Particularly suitable oxidizing agents are, for example, O ₂ ; air;
_Cl2 ; Br; NaOCl, NaOBr, KOCl, LiOCl, Ca
(OCl) ₂ , Ba(OCl) ₂ , Mg(OCl) _{2 ,} alkali or alkaline earth metal oxyhalides, and mixtures thereof. The oxidizing agent is used in an amount sufficient to convert substantially all of the Cu ⁺ to Cu ⁺⁺ while rendering the copper salt soluble in the aqueous phase. Therefore, at least one equivalent of oxidizing agent is used per equivalent of cuprous ion, preferably about 1 to about 5 equivalents, and most preferably about 1.1 to about 1.5 equivalents.

In some cases it may be desirable to slightly acidify the aqueous mixture to a pH of 7 or less before contacting it with the oxidizing agent. When simultaneously using oxidizing agents such as alkali or alkaline earth metal oxyhalides, the rate of the oxidation process is particularly increased since they oxidize more efficiently under acidic conditions.

Suitable metals that are environmentally acceptable for biological treatment vessels include, for example, Fe, Al, Mg and mixtures thereof, with aluminum being preferred. The amount of metal is sufficient to reduce substantially all of the cuprous (Cu ⁺ ) or cupric (Cu ⁺⁺ ) to metallic copper, thus reducing the amount of cuprous or cupric ion 1 at least 1 equivalent per equivalent, preferably about 1 to about 10 equivalents,
Most preferably about 1.0 to about 2.0 equivalents of metal are used.

In step (1), the spent solvent solution is usually preferably added to water, but water can also be added to the solvent solution. Although the temperature can be suitably selected, temperatures of 0°C to about 100°C, preferably about 5°C to about 25°C are particularly suitable.

In the separation step, the aqueous phase and the organic phase are separated by any known method, such as using specific gravity differences, tilted plate separation, or injecting air bubbles into the phase mixture (air flotation). separated.

The organic phase obtained from the separation step can then be treated by environmentally acceptable means, such as combustion.

The precipitated metallic copper can be recovered by suitable means such as filtration, decantation, centrifugation, etc.
The resulting aqueous salt can then be processed through a biological treatment tank.

The following examples are illustrative of the invention but should not be construed as limiting the scope of the invention in any way.

Reference example 0.1179 mol of CuAlCl ₄ was added to a beaker containing 202.0 g of an aqueous solution of 1 mH ₂ SO ₄ at room temperature (23°C).
(Cu ⁺ 0.1179 equivalents) of used
51.710 g of CuAlCl ₄ toluene complexing agent solution was added. The mixture was stirred for 30 minutes, during which time an exotherm was observed. The mixture became an aqueous phase and an organic phase, which were separated.

2.7 g powdered magnesium (0.222
(equivalent) to precipitate metallic copper, and 5 g (0.0787 equivalent) of metallic copper was recovered by filtration. 66.75% of the copper contained in the spent solution was recovered.

Example: In a beaker containing 203.13 g of water, 10.25 g
(0.1613 mol) of used copper
69.36 g of CuAlCl ₄ toluene complexing agent solution was added. At the beginning of this addition the temperature was 6°C;
A maximum temperature of 47°C was reached during hydrolysis. After cooling to room temperature, the organic and aqueous phases were separated using a separatory funnel. The aqueous phase containing undissolved cuprous chloride was treated with air using a gaseous dispersant and the solution was stirred using a magnetic stirrer. Then the dissolved second
Magnesium in copper chloride (Cu ⁺⁺ 0.323 equivalents)
It was reduced to metallic copper by adding 4.40 g (0.362 equivalents). Magnesium was added slowly. 9.76 g of metallic copper was recovered by the filtration, corresponding to a copper removal yield of 95.22% of the copper contained in the spent solution.

Claims (1)

[Claims] 1 (a) A spent cuprous aluminum tetrahalide complexing agent solution is mixed with at least 0.5 part of water per part of the complexing agent solution, thereby forming a cuprous aluminum tetrahalide complexing agent solution. (b) stirring the mixture of step (a) and contacting it with a sufficient amount of a suitable oxidizing agent for a sufficient period of time to form a water-insoluble first phase; converting the copper halide to a water-soluble cupric halide; (c) separating the organic phase from the aqueous phase; a spent cuprous aluminum tetrahalide complexing agent comprising contacting with an environmentally acceptable metal thereby precipitating metallic copper; and (e) recovering the precipitated metallic copper by suitable means. How to remove copper from solution. 2. The method of claim 1, wherein the metal with an electrification series higher than copper is selected from the group consisting of iron, aluminum and magnesium and mixtures thereof. 3 (a) Mixing a spent cuprous aluminum tetrahalide complexing agent solution with at least 0.5 part water per part of said complexing agent solution, thereby forming a solid precipitate of cuprous halide, an organic phase and (b) separating the organic and aqueous phases; (c) treating the aqueous phase containing the insoluble cuprous halide with a sufficient amount of a suitable oxidizing agent while stirring; (d) converting the aqueous phase containing the dissolved cupric halide to a metal having an electrification series higher than that of copper and environmentally friendly; (e) recovering the precipitated copper metal by suitable means. How to remove copper. 4. The method of claim 3, wherein the complexing agent solution is cuprous aluminum tetrahalide in toluene. 5 The amount of water is 0.95 to 1.05 parts by weight of complexing agent solution.
and the amount of metal with an electrification series higher than that of copper is 1 to 2 equivalents per equivalent of copper, and wherein the oxidizing agent is oxygen introduced in substantially pure form or as air. The method described in Section 4. 6. The method according to claim 5, wherein the metal whose electrification series is higher than copper is magnesium. 7. The oxidizing agent is calcium hypochlorite, and the aqueous mixture is acidified to a pH below 7 before or during contact with the calcium hypochlorite. Method.