CN1209290C

CN1209290C - Method of preparing anhydrous aluminium chloride

Info

Publication number: CN1209290C
Application number: CN 02129997
Authority: CN
Inventors: 章浩龙
Original assignee: 章浩龙
Priority date: 2002-09-10
Filing date: 2002-09-10
Publication date: 2005-07-06
Anticipated expiration: 2022-09-10
Also published as: CN1482064A

Abstract

The present invention discloses a method for preparing anhydrous aluminum chloride. In order that the technology for preparing anhydrous aluminum chloride is simple, no exhaust emission exists, and prepared anhydrous aluminum chloride has high purity, aluminum chloride hexahydrate is used as raw materials in the present invention; first, the aluminum chloride hexahydrate is prepared into water solution, alcohol is added into the aluminum chloride hexahydrate water solution, and the alcohol is c1 to c4; after crystals in the solution are completely precipitated, solid-liquid separation is carried out, and separated crystals are anhydrous aluminum chloride. In the production process of the method of the present invention, no exhaust emission exists; after the solid-liquid separation is carried out, the main components of the separated liquid are alcohol, and the alcohol can be recycled and reused; in addition, impurities in the aluminum chloride hexahydrate can be removed, and the purity of the anhydrous aluminum chloride can be increased.

Description

Preparation method of anhydrous aluminum chloride

Technical Field

The invention relates to a preparation method of inorganic salt, in particular to a preparation method of anhydrous aluminum chloride.

Background

Anhydrous aluminum chloride is widely used in organic synthesis catalysts, petroleum cracking catalysts, and the like, and is also widely used in synthesis of detergents, pesticides, dyes, perfumes, metal refining, and the like. At present, most enterprises generally adopt a metallic aluminum method to produce anhydrous aluminum chloride, and the specific method comprises the following steps: putting the preheated aluminum ingot into a closed chlorination reaction furnaceChlorine is sent into the furnace from the upper part along the guide pipe and reacts at the temperature of 800-: and the generated aluminum chloride enters a condenser through a sublimation pipe, and is captured and precipitated to be crystallized, so that a finished product is obtained. The process has the defects that the tail gas is washed by alkaline water in a washing tower during emission, and in addition, the production cost is high.

The process for preparing anhydrous aluminum chloride by using alumina powder-fixed bed method is described in inorganic salt industry handbook 510 published by chemical publishers in 1 month of 1996. The process takes aluminum oxide powder as a main raw material, coal as a reducing agent, pulp waste liquid as an adhesive and chlorine as an oxidizing agent, and the reaction is carried out in the environment of 850-950 ℃, wherein the reaction comprises the following steps: . The process has the following defects: firstly, the tail gas contains a small amount of chlorine and is discharged after being treated; secondly, the prepared anhydrous aluminum chloride has low purity, and the high-purity anhydrous aluminum chloride can be obtained only by sublimation refining; thirdly, the process is complicated.

Disclosure of Invention

Aiming at the defects, the invention provides the method for preparing the anhydrous aluminum chloride, so that the process for preparing the anhydrous aluminum chloride is simple, no waste gas is discharged, and the prepared anhydrous aluminum chloride has high purity.

In order to achieve the purpose, the invention adopts the following technical scheme: a preparation method of anhydrous aluminum chloride adopts aluminum chloride hexahydrate as a raw material, and comprises the following specific processes: preparing aluminum chloride hexahydrate into an aqueous solution, adding methanol or ethanol or n-propanol or ethylene glycol or diethylene glycol or propylene glycol into the aqueous solution of the aluminum chloride hexahydrate, wherein the concentration of the ethanol is 75-99.5%, carrying out solid-liquid separation after crystals in the solution are completely precipitated, and obtaining the separated crystals as anhydrous aluminum chloride.

According to the above method, water-insoluble impurities can be removed by filtration after aluminum chloride hexahydrate is prepared as an aqueous solution.

By adopting the method, no waste gas is discharged in the whole production process, and the main component of the liquid after solid-liquid separation is alcohol, so that the liquid can be recycled and reused, and the environmental protection is facilitated; in addition, in the preparation process, the purity of the anhydrous aluminum chloride can be further improved through the steps of filtering, crystallizing and the like, and experiments prove that the purity of the anhydrous aluminum chloride prepared by the method can reach 99.5 percent; meanwhile, the invention has simple process andlow production cost.

Detailed Description

Example 1

10 g of aluminum chloride hexahydrate is taken and put into a beaker, water is added for dissolving to prepare a solution, 95 percent ethanol is slowly poured into the beaker, after crystals in the beaker are fully separated out, solid-liquid separation is carried out in a centrifugal separator, and white crystals, namely the anhydrous aluminum chloride, are obtained. The concentration of ethanol poured in according to the above method may also be 75%, 99.5%. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. It is also possible to remove impurities by filtration after preparation of the aqueous solution.

Example 2

Taking 10 g of aluminum chloride hexahydrate, putting the aluminum chloride hexahydrate into a beaker, adding water to prepare an aqueous solution, filtering to remove impurities, slowly pouring commercially available methanol, and after crystals in the beaker are fully precipitated, carrying out solid-liquid separation in a centrifugal separator to obtain white crystals, namely the anhydrous aluminum chloride. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. Or filtering to remove impurities after preparing the aluminum chloride hexahydrate into an aqueous solution.

Example 3

Taking 10 g of aluminum chloride hexahydrate, putting the aluminum chloride hexahydrate into a beaker, adding water to prepare an aqueous solution, filtering to remove impurities, slowly pouring commercial n-propanol into the beaker, and after crystals in the beaker are fully precipitated, carryingout solid-liquid separation in a centrifugal separator to obtain white crystals, namely the anhydrous aluminum chloride. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. Or filtering to remove impurities after preparing the aluminum chloride hexahydrate into an aqueous solution.

Example 4

10 g of aluminum chloride hexahydrate is taken and put into a beaker, water is added to prepare an aqueous solution, after impurities are removed by filtration, commercial ethylene glycol is slowly poured into the beaker, and after crystals in the beaker are fully precipitated, solid-liquid separation is carried out in a centrifugal separator to obtain white crystals, namely the anhydrous aluminum chloride. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. Or filtering to remove impurities after preparing the aluminum chloride hexahydrate into an aqueous solution.

Example 5

Taking 10 g of aluminum chloride hexahydrate, putting the aluminum chloride hexahydrate into a beaker, adding water to prepare an aqueous solution, filtering to remove impurities, slowly pouring commercial diethylene glycol, and after crystals in the beaker are fully precipitated, carrying out solid-liquid separation in a centrifugal separator to obtain white crystals, namely the anhydrous aluminum chloride. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. Or filtering to remove impurities after preparing the aluminum chloride hexahydrate into an aqueous solution.

Example 6

Taking 10 g of aluminum chloride hexahydrate, putting the aluminum chloride hexahydrate into a beaker, adding water to prepare an aqueous solution, filtering to remove impurities, slowly pouring commercially available propylene glycol, and after crystals in the beaker are fully precipitated, carrying out solid-liquid separation in a centrifugal separator to obtain white crystals, namely the anhydrous aluminum chloride. The solid-liquid separation according to the above method can also be carried out by other methods such as ordinary filtration. The impurities can also be removed by preparing an aqueous solution from aluminum chloride hexahydrate.

Claims

1. A preparation method of anhydrous aluminum chloride is characterized in that aluminum chloride hexahydrate is adopted as a raw material, and the specific process is as follows:

a. preparing aluminum chloride hexahydrate into an aqueous solution;

b. adding methanol or ethanol or n-propanol or ethylene glycol or diethylene glycol or propylene glycol into the aluminum chloride hexahydrate aqueous solution, wherein the concentration of the ethanol is 75-99.5%;

c. and carrying out solid-liquid separation after crystals in the solution are fully precipitated.

2. The method for preparing anhydrous aluminum chloride according to claim 1, wherein step a is followed by filtration to remove water-insoluble impurities therefrom.

3. The method for producing anhydrous aluminum chloride according to claim 1, wherein the solid-liquid separation is centrifugal separation.