Hydrochloric acid pickling waste liquid resource integrated utilization method for preparing iron oxide and ammonium sulfate

Abstract

The invention relates to a hydrochloric acid pickling waste liquid resource integrated utilization method for preparing iron oxide and ammonium sulfate. Iron-containing hydrochloric acid pickling waste liquid obtained from a pickling treatment process, which uses hydrochloric acid solution as a pickle to remove surface oxides on a steel element, is used as a raw material. The method comprises the following steps of: (1) solid-liquid separation; (2) preheating and heating; (3) miscible displacement; (4) flash evaporation; (5) evaporation and crystallization; (6) solid-liquid separation; (7) mixing and dissolving; (8) pH adjusting; (9) adsorption for impurity removal; (10) solid-liquid separation; (11) neutralization and oxidation; and (12) solid-liquid separation. A liquid phase material is further used for preparation of an ammonium sulfate product, and a solid phase material is further used for preparation of an iron oxide product; besides, ammonium sulfate by-products can be prepared in further preparation of the ammonium sulfate product. The invention has advantages of reasonable technology, simple method, environment-friendliness, 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 the comprehensive utilization of hydrochloric acid pickling waste liquid resources to prepare iron oxide and ammonium sulfate, which uses hydrochloric acid solution as the pickling liquid to carry out pickling treatment on iron and steel components to remove the iron-containing oxides obtained during the process of removing surface oxides. The method for preparing ferric oxide and ammonium sulfate by using hydrochloric acid pickling waste liquid as a raw material for resource utilization and comprehensive utilization 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 groun...

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.

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