Method for producing polyaluminium chloride by-product of producing diethyl methylphosphonite

Abstract

The invention relates to a method for producing poly aluminum chloride by using a byproduct of diethyl methylphosphonate production. The method comprises the following steps: (1) slowly adding a byproduct sodium tetrachloraluminate, rich in sodium tetrachloraluminate and obtained in a production process of diethyl methylphosphonate, into a dissolving kettle for dissolution, and collecting the solution; (2) adding ferric trichloride and hydrochloric acid; (3) sequentially adding aluminum hydroxide and calcium metaaluminate for polymerization reaction; (4) controlling the temperature to be 100 DEG C, and performing thermal reaction for 75min; and (5) cooling, and performing solid-liquid separation, wherein the filtrate is the product of the invention. The method disclosed by the invention has the advantages of simple process, high efficiency, low consumption, energy conservation, greenness and environmental friendliness and low cost.

Description

Technical field [0001] The invention relates to a production method of polyaluminum chloride, in particular to a method for producing polyaluminum chloride by using the by-product of producing diethyl methylphosphonite. Background technique [0002] In water treatment, flocculation is an important and widely used process method. It aggregates colloidal substances and small suspended particles into large aggregates through chemical mechanisms to improve the absorption of various impurities in the water by these aggregates , Which is conducive to the subsequent sewage treatment. Polyaluminum chloride has different production processes due to different raw materials. High efficiency, low consumption, environmental protection, and low cost are the goals pursued by the preparation of polyaluminum chloride. At present, the common preparation methods of polyaluminum include the following: [0003] ① Preparation method using aluminum scraps, aluminum ash, and aluminum slag as raw materia...

AI Technical Summary

Problems solved by technology

But the shortcoming of this method is: impurity content is on the high side in the product, especially metal element content exceeds standard, and product quality is unstable, and equipment corrosion is serious; Aluminum ash itself belongs to explosive material, and produces a large amount of flammable and explosive gases in the production process and dust, etc., the production process is relatively strict, and improper control is likely to cause explosions, poor safety, and the operating environment is harsh and the pollution is serious

[0012] The disadvantages are: the heavy metals in the aluminum-containing mineral raw materials will eventually enter the PAC products, causing the heavy metal elements to exceed the standard; a few enterprises use the by-product hydrochloric acid as the raw material, which will bring a variety of organic pollutants into the product, resulting in a high content of insolubles in the product, affecting water treatment. Enterprise equipment operation and production environment; adding calcium aluminate to adjust the basicity, so that the PAC product contains a large amount of calcium chloride impurities, which increases the consumption of hydrochloric acid and water treatment costs; the amount of slag is large, and the appearance is poor due to the high iron content

The disadvantages of this process are: high cost of raw materials, high equipment requirements, and large investment

Although aluminum hydroxide will be used as raw material to prepare polyaluminum chloride for drinking water, its production process requires high pressure and high temperature, and high energy consumption; low-consumption and high-efficiency The research and development of production technology is particularly important

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