A preparing process of energy-saving environmental-friendly type modified polymeric ferric sulfate

Abstract

The invention relates to a preparing process of energy-saving environmental-friendly type modified polymeric ferric sulfate. The process includes following steps: adding polyaluminum chloride waste slag and a sulfuric acid type ferrous sulfate-acid mixture into a pretreatment kettle, heating, stirring, reacting and performing filter pressing to obtain a first reaction liquid material; adding green vitriol and a sulfuric acid type ferrous sulfate-acid mixture into a pretreatment kettle and stirring to obtain a second reaction liquid material; and adding the first and second reaction liquid materials into a sealed acid-resistant pressure-resistant reactor, adding a catalyst solution and a cocatalyst solution, feeding oxygen, heating, reacting, and cooling to obtain a modified polymeric ferric sulfate solution. The beneficial effects of the process are that the polymeric ferric sulfate containing a trace amount of aluminum and silicon is high in added value, has flocculation effects superior to flocculation effects of polymeric ferric sulfate, and can be used for treatment of high-turbidity high-COD printing and dying waste water; production raw materials are all industrial waste materials; the raw material cost is reduced; reaction time is shortened; and the time cost is saved.

Description

technical field [0001] The invention relates to a preparation process of energy-saving and environment-friendly modified polyferric sulfate. Background technique [0002] As traditional inorganic flocculants, iron salts and aluminum salts have become the two most commonly used water purification materials in the sewage treatment agent market. Polyferric sulfate (PFS) and polyferric chloride are currently developed iron salt flocculants, and the product that has been practically used is polyferric sulfate. When polyferric sulfate is used for coagulation treatment, because of its small solubility product constant, fast hydrolysis speed, dense flocs and large quality, good sludge dehydration, and a wide pH range of suitable water, it is suitable for decolorization of industrial wastewater such as printing and dyeing, papermaking, etc. , In addition to COD effect is better. However, polyferric sulfate is highly acidic and corrosive, and it is often accompanied by yellowing of ...

AI Technical Summary

Problems solved by technology

The advantage of oxidizing agent oxidation method is that reaction time is short, and oxidation efficiency is high, but the raw material cost of oxidizing agent is expensive, and CN101037234A analyzes and produces the oxidizing agent cost that every ton of polyferric sulfate uses is 137 yuan (oxidizing agent is example with sodium chlorate), and raw material cost is too high , which is not conducive to the industrial production of enterprises

The second method, the catalytic oxidation method, has become the preferred polyferric sulfate production process for enterprises due to its low production cost, but the catalyst added in the catalytic oxidation method will release acid gases such as nitrogen oxides during the reaction stage, and The reaction time of this method is relatively long, generally 4-5 hours. In actual production, in order to ensure the oxidation rate of ferrous iron, the reaction time is 8-10 hours or even longer.