Preparation method of high-concentration polymerized ferric chloride

Abstract

The invention discloses a preparation method of high-concentration polymerized ferric chloride. The method comprises the following steps: 1, putting the following raw materials in parts by mass: 140-190 parts of ferrous chloride, 80-110 parts of pickling waste liquid, 10-20 parts of 20-30% hydrochloric acid and 8-15 parts of an oxidizing agent into a reaction kettle for polymerization reaction toobtain traditional polyferric chloride, 2, cooling the traditional polyferric chloride obtained in the step 1 to 35 DEG C or below, and 3, putting the following raw materials in parts by mass: 100 parts of the polyferric chloride obtained in the step 2, 80-130 parts of ferrous chloride, 10-30 parts of 20-30% hydrochloric acid and 5-10 parts of an oxidizing agent into a reaction kettle, and carrying out polymerization reaction to obtain the high-concentration polyferric chloride. According to the invention, an innovative two-stage production method is adopted for production of high-concentration polymerized ferric chloride, the total iron content in the high-concentration polymeric ferric chloride can be adjusted to 14-16%, the pH value of a 1% solution is controlled to 1.5-3, and in the field of wastewater treatment, the high-concentration polymeric ferric chloride has better removal effect and cost advantage than traditional polymeric ferric chloride.

Description

technical field [0001] The invention relates to the technical field of preparing chlorine-polymerized ferric chloride, in particular to a method for preparing high-concentration polymerized ferric chloride. Background technique [0002] Polyferric chloride is a commonly used water treatment agent for sewage treatment. With its own bridging connection and adsorption capacity, it has certain treatment effects in removing COD, total phosphorus, heavy metal ions and decolorization in water. [0003] In actual production, the total iron content of liquid polyferric chloride is generally ≥9%, and the pH of 1% aqueous solution is 2-3. In practical applications, this kind of product has limited ability to remove COD and total phosphorus. In order to enhance the removal effect, it is generally passed It can be achieved by increasing the dosage, but the removal rate of the existing polyferric chloride will not change after adding a certain amount, and the pH of the water body is acidi...

AI Technical Summary

Problems solved by technology

[0003] In actual production, the total iron content of liquid polyferric chloride is generally ≥9%, and the pH of 1% aqueous solution is 2-3. In practical applications, this kind of product has limited ability to remove COD and total phosphorus. In order to enhance the removal effect, it is generally passed It can be achieved by increasing the dosage, but the removal rate of the existing polyferric chloride will not change after adding a certain amount, and the pH of the water body is acidic due to the acidic structure of the agent itself, and the water body turns yellow and affects the discharge. Therefore, it is necessary to add a certain amount of alkali to adjust the pH, resulting in an increase in processing costs

[0004] If the total iron content of the liquid product is increased, it can not only improve the effective treatment effect of the agent per unit volume, reduce the amount of agent added, and can be directly added to the water through the metering pump without diluting with water, saving freight and labor costs. It reduces the amount of alkali added due to the pH adjustment of the water body, which can save a large part of the processing cost for the user. However, in actual production, the polyferric chloride is made of ferrous chloride, pickling waste liquid, hydrochloric acid solution, and oxidizing agent. The three are added in a certain proportion to the reactor for oxidative polymerization. If the total iron is to be increased to more than 12%, it is necessary to increase the dosage of ferrous chloride, which will inevitably break the solid-liquid balance in the original formula, and also It directly increases the salinity (that is, the degree of alkalinity) of the medicament, and the OH in the medicament - increase, under the influence of the copolymerization temperature of 60-70°C, more ferric hydroxide precipitates will be generated, resulting in a large amount of yellow insoluble matter in the agent, and the agent will fail. Therefore, how to solve the influence of temperature and basicity on the stability of the agent has become a production Key Technical Problems of High Concentration Polyferric

Images