Method for preparing iron oxide and ammonium sulfate by using hydrochloric acid washing waste liquid

Abstract

The invention relates to a method for preparing iron oxide and ammonium sulfate by using a hydrochloric acid washing waste liquid, wherein an iron and steel element is subjected to acid washing treatment by using a hydrochloric acid solution as an acid washing liquid to remove surface oxides so as to obtain an iron-containing hydrochloric acid washing waste liquid, and the iron-containing hydrochloric acid washing waste liquid is used as the raw material of the method. The method comprises: (1) solid-liquid separation; (2) preheating and heating; (3) mixed displacement; (4) flash evaporation;(5) evaporation crystallization; (6) solid-liquid separation (7) mixed dissolution; (8) pH value adjustment; (9) adsorption and impurity removal; (10) solid-liquid separation; (11) neutralization oxidation; and (12) solid-liquid separation, wherein the liquid phase material is further prepared into the sulfuric acid product, the solid phase material is further prepared into the iron oxide products, and an ammonium sulfate by-product can be prepared during the preparation of an ammonium sulfate product. According to the present invention, the method has characteristics of reasonable process, simple method, environmental protection, energy saving, low preparation cost, good product quality and high utilization rate of valuable components.

Description

technical field [0001] The invention relates to a method for preparing iron oxide and ammonium sulfate from hydrochloric acid pickling waste liquid, which uses hydrochloric acid solution as pickling liquid to pickle iron and steel components to remove iron-containing hydrochloric acid waste pickling liquid obtained in the process of removing surface oxides The method for preparing ferric oxide and ammonium sulfate by resource comprehensive utilization as raw materials belongs to the field of environmental chemical industry. Background technique [0002] Iron oxide is a hexagonal crystal system with a molecular formula of α-Fe 2 o 3 , has the characteristics of non-toxic, alkali resistance, heat resistance, etc., the decomposition temperature is 1560 ℃, it is light reddish brown, it turns gray black when it is burned strongly, but it turns red again when it is ground into powder. Iron oxide is widely used in building materials, paints, coatings, papermaking, rubber, ceramic...

AI Technical Summary

Problems solved by technology

The hydrochloric acid pickling waste liquid is strongly hydrochloric acid. If it is directly discharged, it will inevitably lead to waste of resources and environmental pollution. On the one hand, the valuable components in the hydrochloric acid pickling waste liquid cannot be fully utilized, resulting in a large amount of waste of resources. On the other hand, it causes serious environmental pollution; and if the harmless treatment is carried out alone, the treatment cost will be greatly increased. The high treatment cost and extremely low cost performance make it difficult to apply the harmless treatment alone in practice.