A kind of preparation method of solid polyferric sulfate

Abstract

The invention relates to a preparation method of solid polymeric ferric sulfate. The method comprises the following steps: firstly, adding industrial ferrous sulfate heptahydrate into a reaction kettle, starting stirring, and adding concentrated sulfuric acid with a mass concentration of 93% into the reaction kettle in a spraying manner; then heating to 90-100 DEG C to remove some of the bound water in ferrous sulfate heptahydrate; after 1-1.5 h, adding a clean oxidant to react at 50-100 DEG C for 0.5-3 h, until the divalent iron is completely oxidized, so that a red-brown liquid is obtained;and finally, transferring all the red-brown liquid into an aging chamber, standing for 0.5-1 day to obtain a precipitate, drying the precipitate, and crushing the dried precipitate to 120 mesh, so that a solid polymeric ferric sulfate powder is obtained. The preparation method of the solid polymeric ferric sulfate has low production cost, simple operation flow and high production efficiency. The product obtained by adopting the preparation method has high solubility, fast dissolving speed and wide application, and can not only evolve sewage, but also evolve drinking water.

Description

technical field [0001] The invention relates to a preparation method of polyferric sulfate, in particular to a preparation method of solid polyferric sulfate. Background technique [0002] Polyferric sulfate is an inorganic polymer water treatment agent flocculant, which has a significant removal effect on chemical oxygen demand, biochemical oxygen demand, suspended solids, and chroma. At present, iron salts and aluminum salts are mainly used as water treatment agents, but metal aluminum has great harm to human health, and it has great advantages compared with aluminum salt flocculants. [0003] Polyferric sulfate is divided into liquid polyferric sulfate and solid polyferric sulfate, but due to the storage and transportation of liquid polyferric sulfate, its application is largely limited, while solid polyferric sulfate overcomes the problem of liquid polyferric sulfate. disadvantages, and therefore has a strong competitiveness. [0004] There are three main methods for p...

AI Technical Summary

Problems solved by technology

One is to make a liquid first, and then use spray drying or vacuum concentration to obtain a solid. This type of production equipment requires large investment, complex equipment, and high energy consumption.

The second is the dehydration oxidation method involved in the patent document CN1105342, which uses nitric acid as an oxidant, and the production process produces harmful gases that pollute the environment

The third is the method involved in the patent document CN102718268. The heating oxidation method is used to prepare polyferric sulfate. It uses direct heating of solid ferrous sulfate heptahydrate to make it muddy, because there are gaps between the solid particles and there are many problems such as difficulty in stirring the solid. , so the process is time-consuming, and the energy consumption also increases accordingly, and the subsequent drying process is omitted by using the ammonium salt water-locking ability, but the oxidation process uses 50% hydrogen peroxide, substitutes a large amount of water molecules, and adds ammonium salt to directly lock water to make crystal water High content, it is difficult to guarantee the total iron content of the product

The above three methods all have the problems of high energy consumption and low production efficiency.