KR0161098B1 - Method for manufacturing aluminum chloride anhydride and zinc - Google Patents

Abstract

The present invention provides a method for producing high purity metal zinc and high purity aluminum chloride by applying metathesis substitution reaction by applying zinc chloride and aluminum metal powder or melt. In addition, in order to obtain a high purity of the obtained aluminum chloride of the present invention, gaseous aluminum chloride containing a small amount of zinc chloride produced in the reaction can be passed through a tube containing aluminum granules to be purified by contacting aluminum.

Description

Simultaneous preparation of anhydrous aluminum chloride and zinc

The present invention relates to a method for simultaneously producing anhydrous aluminum chloride and zinc. More particularly, the present invention relates to a method of recovering zinc which is molten at 420 ° C. by gravity, while recovering by cooling and condensing anhydrous aluminum chloride which is sublimed at 183 ° C. by mixing and heating metal aluminum in an equivalent ratio to zinc chloride. .

Anhydrous aluminum chloride (AlCl ₃ ) is used as an acid catalyst for petroleum cracking and Friedel Kraft reactions, and its hexahydrate is an additive such as wool refining, wood preservatives, dyeing, petroleum refining, papermaking, paint, paint, printing ink, etc. About 3,000 tons are imported and used annually, and about 10,000 tons are used for water purification. In addition, more than 500,000 tons of metal zinc (Zn) is produced or imported in Korea annually and used in large quantities for steel plate plating, pipe plating, die cast, copper alloy, and the like.

Many methods for producing anhydrous aluminum chloride have been conventionally proposed, and these methods include, for example, a method of reacting metal aluminum with chlorine at high temperature; A method of reacting metal aluminum with hydrogen chloride gas at high temperature; Reacting alumina containing materials such as alumina or bauxite with carbon monoxide and chlorine or phosgene; Alumina or an alumina containing material can be divided into a method of reacting with chlorine in the presence of carbon.

At present, the industrial method generally employs a method of reacting metal aluminum with chlorine or hydrochloric acid at a high temperature. Specifically, aluminum chloride sublimed while blowing chlorine gas into molten aluminum is cooled to form a powder or mass. Aluminum chloride is manufactured. However, in such a method, metal aluminum, which is a raw material, generally melts alumina at about 960 ° C. or more, and is produced by electrolysis, thereby increasing the cost. Due to these drawbacks, a method of producing anhydrous aluminum chloride by reacting with alumina (Al ₂ O ₃ ) in the presence of a reducing agent (mainly carbon) in a molten salt bath containing an alkali metal or an alkaline earth metal halide (Japanese Patent Publication No. 2-293) ), A method of reacting an oxide of aluminum and a chlorinated hydrocarbon at a high temperature in the absence of a catalyst (Japanese Patent Application Laid-Open No. 1-54286), and a method of reacting the presence of cycloalkane vapor in order to increase the contact reaction rate between metal aluminum and hydrogen chloride. (JP-A 57-13499), a raw material mixture of an aluminum-containing material, a fine particle of a carbon-containing material and a binder is fired, and the resulting fired mixture is chlorinated using gaseous oxygen-containing chlorine to obtain aluminum chloride. Method (Japanese Patent Publication No. 3-51655) and the like have been proposed, and also to increase the purity of the obtained aluminum chloride Methods (e.g., JP-A-53-38277, JP-A-56-35611, JP-A-58-50931, JP-A-59-5526, etc.) have been proposed.

The above-mentioned known methods use relatively expensive chlorine as a raw material, and generate anhydrous aluminum chloride, carbon monoxide, and carbon dioxide gas at the same time by contacting with a reducing agent carbon and aluminum oxide (Al ₂ O ₃ , bauxite) at high temperature, The composite gas phase is cooled and refined to produce high purity aluminum chloride.

In addition, as a conventional method, metal zinc is known in a dry manufacturing method and a wet manufacturing method.

Applicant has been producing and selling zinc chloride and zinc for a long time, and the present inventors have been continuously researching related to the above products, and the present inventors can easily and inexpensively manufacture aluminum chloride and zinc by reacting zinc chloride and aluminum. It was found that the present invention was completed.

Hereinafter, the present invention will be described in detail.

The present invention attaches a stirrer to a molten bath of anhydrous zinc chloride (ZnCl ₂ ), and reacts aluminum powder while stirring zinc chloride to obtain aluminum chloride and zinc.

This is represented by the following formula.

3ZnCl2 + 2Al 3Zn + 2AlCl ₃

That is, in the present invention, when a predetermined amount of aluminum molten metal or aluminum powder is added to a high-purity zinc chloride melting bath and stirred, the reaction is carried out while maintaining the average temperature at 420 to 500 ° C. Cooling, desublimation to obtain powder or flakes.

On the other hand, metal zinc (Zn) is formed in the lower portion of the zinc chloride melt and settles due to the gravity difference. This is discharged through the drain pipe in the lower part of the bath and guided to the zinc mold to solidify the product.

The reaction conditions are suitable in the above temperature range, zinc chloride is evaporated above 740 ℃ to contaminate the product of aluminum chloride sublimation, it is inconvenient, and below 420 ℃ below the melting point of zinc (420 ℃) it is continuous discharge of zinc Becomes difficult. Because of the physical properties of these reactants and products, the reaction temperature is preferably 420 ~ 500 ℃, especially 450 ~ 480 ℃.

The purity of the zinc (Zn) metal produced in the process of the present invention depends on the purity of the zinc chloride as a reaction raw material. That is, when using a high-purity zinc chloride of 1 ~ 100ppm or less heavy metals such as iron, nickel, cadmium, etc. in zinc chloride, or using a product obtained by removing and purifying the metal component in zinc chloride, zinc produced is 99.99%. Or 99.999% high purity products.

On the other hand, sublimated high-purity aluminum chloride is led to a multi-stage contact distillation column, while maintaining the vapor temperature of 185 ~ 380 ° C to remove the accompanying zinc chloride vapor as much as possible, in the next step through the aluminum particle (3 ~ 10mm) layer After a small amount of zinc chloride present in the aluminum chloride gas is brought into contact with the aluminum layer, the aluminum chloride gas of high purity is quenched to obtain a powder or flake form.

Although the reaction of the present invention can be carried out in a batch type, it is preferable to use a continuous process because it is difficult to adjust the reaction ratio of the zinc chloride and aluminum as the reactants. That is, by continuously supplying zinc chloride melt and aluminum powder or aluminum molten metal continuously during the reaction in the reactor, it is possible to sufficiently produce 10 to 100 tons of daily output.

In the conventional method, chlorine or hydrogen chloride gas is reacted to obtain aluminum chloride, but in the present invention, zinc chloride is reacted with hydrochloric acid solution to obtain zinc chloride without using such a toxic gas, which is obtained from aluminum metal or aluminum scrap. Aluminum chloride and zinc metal can be obtained in high purity by substitution reaction of the obtained aluminum powder or aluminum melt, and it is very economical because the reaction proceeds and is completed at a considerably lower temperature than the conventional method.

Example 1

200 g of high purity zinc chloride and 26.39 g of high purity aluminum powder corresponding to the equivalent ratio are put in a Erlenmeyer flask, and heated for 40 minutes while maintaining an average temperature of 480 ° C. 92.16 g (96.07%) of zinc metal was obtained from the bottom of the vessel. The yield of zinc in this reaction is about 96%, the loss due to unreacted and unprogressed by discontinuous reactions.

Example 2

210.5 g of zinc chloride purity, 2% iron, 1% Pb, 2% ZnO, and 20.5 g of aluminum (Al) equivalent to the equivalents were added at an average temperature of 480 ° C. About 97.4 g of impure metals, such as%, Fe 1%, and Pb 0.5%, were recovered. Purification of zinc chloride is inevitable, and it has been experimentally demonstrated that iron, cadmium, lead, and other heavy metal chlorine compounds in zinc chloride melt are co-reduced with aluminum and alloyed with zinc metal to reduce product purity.

Example 3

200 g of purified high purity zinc chloride (ZnCl ₂ ) and 26.4 g of aluminum were put into a 500 cc Erlenmeyer flask to collect aluminum chloride (AlCl ₃ ) vapor generated by heating (480 ° C.). (ZnCl ₂ ). In order to remove this zinc chloride (ZnCl ₂ ), aluminum granule particles (diameter 3 mm to 5 mm) are placed in an aluminum chloride vapor induction pipe to be 2/3 (average) of the tube (total length 1 m), and the average temperature of the tube is 380 ° C. After allowing to pass through, the mixture was cooled and crystallized to obtain about 130.44 g of aluminum chloride. The analysis of the aluminum chloride, and the purity was 99.99% average, the remaining amount of zinc chloride (ZnCl ₂₎ was less than 0.1ppm.

Example 4

40 g of aluminum powder and 200 g of purified zinc chloride were placed in a 500 cc flask, and the zinc produced after the completion of the heating reaction was made of a significant amount of an alloy of aluminum. The high-purity aluminum alloy was added to high-purity zinc chloride again, followed by stirring to obtain high-purity zinc (99.99%). Aluminum / zinc alloys are also selectively removed only when given sufficient stirring temperatures.

Claims (3)

A method of producing high purity metal zinc and high purity aluminum chloride, characterized in that the zinc chloride is melted by maintaining the temperature in the reactor at 420-500 ° C., and aluminum metal powder is added thereto to perform a substitution reaction. The method of claim 1, wherein the average temperature of the reaction is maintained at 450 ~ 480 ℃. The method of claim 1 wherein the gaseous aluminum chloride produced in the reaction is passed through a tube containing aluminum granules to remove traces of zinc chloride contained in aluminum chloride.