Anhydrous reaction method for preparing polymeric ferric sulfate

Abstract

An anhydrous reaction method for preparing polymeric ferric sulfate is disclosed. According to the method, 2-20 tons of industrial ferrous sulfate and 0.2-1.8 tons of sulfuric acid are added into a specialized stainless steel reaction unit with its volume being 2-20 cubic meters, and the ratio of ferrous sulfate to sulfuric acid is 10:1; in a nearly vacuum state, 2.5-3.5 kg of a catalyst is poured according to each ton of ferrous sulfate, the catalyst is sodium nitrite or dilute nitric acid, and dissolution and reaction are carried out in the same unit; after an oxygen valve reaches 0.02 MPa, pump type stirring is started, pressure is maintained at 0.02-0.04 MPa, reaction temperature is within 100 DEG C, and the reaction lasts for 3-10 h; after qualified through sampling analysis, an emptying valve is turned on, and a few tail gas is sent into an alkali absorption tower to be treated; after saturated, lye returns to be recycled as a catalyst; polymeric ferric sulfate is directly put into a spray drying tower to be dried, so as to obtain a polymeric ferric sulfate spray-dried product. Moisture content of the produced polymeric ferric sulfate is reduced to 25%, standard coal is saved by 65 kg, energy consumption is reduced by 50%, exhaust gas is minimized by 2 / 3, and production cost is greatly decreased.

Description

technical field [0001] The invention relates to a production method of solid polyferric sulfate, in particular to a method for preparing polyferric sulfate by anhydrous reaction. The product is used as a water purifier. Background technique [0002] The existing production method of solid polyferric sulfate is to add water to the raw material, dissolve it by steam heating or add a large amount of water, then pump it to the reaction tower for oxidation reaction, and then send the liquid product to concentration or spray drying, and its moisture content is about 50%. To produce one ton of solid polyferric sulfate requires 1 million kcal of heat, 200kg of standard coal, 10-12kg of catalyst, several dissolution kettles or tanks, and even boilers. There are defects such as high energy consumption, large amount of catalyst, long reaction time, and many equipments. Chinese patent application number 201210191010.9 discloses "a method for producing solid polyferric sulfate", which ...

AI Technical Summary

Problems solved by technology

There are defects such as high energy consumption, large amount of catalyst, long reaction time, and many equipments