Method for preparing solid polymeric aluminum ferric sulfate

Abstract

The invention discloses a preparation method of solid polymeric ferroaluminum sulfate, comprising the following steps: (1) basic ferric sulfate is prepared from ferrous sulfate; (2) water, sulfuric acid and hydrogen peroxide are added into the basic ferric sulfate in sequence, stirring and standing; (3) an aluminized compound is added and further stirred; (4) being self-cured and precipitated under dry condition; and (5) being aged at room temperature and crushed so to obtain a product. The invention uses a blast oxidation process and solves the pollution problem which is generated by the catalytic oxidation process in the traditional iron-based coagulant industry. The polymeric ferroaluminum sulfate is a solid product; compared with the liquid product, the polymeric ferroaluminum sulfate has advantages of storage and transportation, has long service life, and does not need evaporation or decompression evaporation process, and the coagulation active component of the product is retained to the largest extent. Quality indicators such as basicity, active component, and the like are all higher than the quality indicators in the prior art. When in actual implementation and embodiment of water body, the effect of the polymeric ferroaluminum sulfate is better than the effect of the inorganic coagulant such as polyaluminum chloride polymeric ferroaluminum sulfate and the like.

Description

technical field [0001] The invention relates to a preparation process of solid polyaluminum ferric sulfate. Background technique [0002] The inorganic polymer coagulant industry began in Japan. In the 1960s and 1970s, Japan successively developed the production technology of polyaluminum chloride and polyferric sulfate. However, in practical application, it is found that the combination of polyaluminum and polyiron has more effective functions of removing turbidity, reducing COD and decolorizing than using a coagulant alone. In the late 1980s, some reports proposed the concept of polyaluminum ferric sulfate copolymerized with iron and aluminum, and reported its preparation scheme. Chinese patent CN94117429.8 proposes a production method using ferrous sulfate as a raw material and aluminum nitrate as a catalyst to prepare polyaluminum ferric sulfate, but aluminum nitrate is also used as an aluminum component in this method, so the aluminum component content in the product i...

AI Technical Summary

Problems solved by technology

Chinese patent CN94117429.8 proposes a production method using ferrous sulfate as a raw material and aluminum nitrate as a catalyst to prepare polyaluminum ferric sulfate, but aluminum nitrate is also used as an aluminum component in this method, so the aluminum component content in the product is limited; At the same time, pure oxygen is used as the oxidant, the reaction system requires high system pressure requirements, and the production cost is high; moreover, the product is in a liquid state, which is inconvenient for transportation and storage

CN01133248.4 also utilizes industrial waste residues to produce polyaluminum ferric sulfate. The basicity of the product is only 7-9%. Although it is a solid product, it is obtained by evaporation and dehydration of a liquid product. The process requires a lot of energy consumption

Moreover, it has been reported that the heating and dehydration of liquid polyaluminium-iron will lead to the conversion of the active components of the coagulant to the inert components, resulting in low flocculation efficiency.

CN91109828.3 has reported a kind of method for preparing solid polyferric sulfate, and this method takes ferrous sulfate as raw material, takes air as oxidant, makes polyferric intermediate by ventilating and heating, then obtains product with sulfuric acid telomerization, and this product is obtained by natural After solidification, aging and pulverization, solid polyferrous products are obtained. There are similar reports of this method abroad, but this method does not introduce aluminum components, and it is a single polyferric (PFS) rather than iron-aluminum copolymer (PAFS).