Method for recycling iron-containing zinc-containing sludge to prepare zinc hydroxide and dye-grade iron oxide red

Abstract

The invention relates to a method for recycling iron-containing zinc-containing sludge to prepare zinc hydroxide and dye-grade iron oxide red and belongs to the field of waste resourceful treatment. The method comprises the steps of adding hydrochloric acid into iron-containing zinc-containing sludge to adjusting a pH value, then adding steel scrap, stirring, extracting in an extraction agent, classifying and deoiling; performing back extraction on zinc-containing load organic phase to prepare zinc hydroxide; adding alkaline substance into ferrous chloride solution with the zinc content smaller than or equal to 1g / L to adjust a pH value to be 8.5 to 13.0, introducing oxidizing gas, oxidizing for 60 to 1500min, warming to 50 to 90 DEG C, adding alkaline substance to adjust a pH value as 2.3 to 3.5, introducing oxidizing gas, oxidizing for 30 to 120h, guaranteeing the pH value of liquid is 2.3 to 3.5 in an oxidizing process, finishing oxidization, filtering and drying to obtain the dye-grade iron oxide red. The method is a recycling technology of iron-containing zinc-containing sludge in a hot galvanizing factory and has the advantages of small equipment invest, low energy consumption and high purity of a prepared product.

Description

technical field [0001] The invention belongs to the technical field of waste resource treatment, and in particular relates to a method for preparing zinc hydroxide and dye-grade iron oxide red by recycling iron-containing and zinc-containing sludge. . Background technique [0002] The iron-containing sludge of the hot-dip galvanizing plant is the polluting waste slag discharged from the pickling water of the hot-dip galvanizing plant workshop. It is an industrial solid waste produced by adjusting the pH and aeration. Generally, the iron content is relatively large. Due to the differences in the processes of various manufacturers, the iron content is usually between 20-50%, and the zinc content is 1-7%. The main pollutants of the sludge are ferric oxide, ferric hydroxide, ferrous hydroxide, zinc hydroxide, zinc oxide and so on. In addition to occupying a large amount of land during the stacking process, the sludge is also easily contaminated due to the infiltration of these ...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent ZL201410007225.X discloses a process for preparing iron oxide by solution oxidation, liquid-solid separation and high-temperature calcination, using acidic FeCl 2 The solution is prepared by solution oxidation to FeCl 3 solution, adjust the pH to make Fe 3+ Separation of Fe(OH) from solution as precipitate 3 , and then prepared Fe by filtration, drying and high-temperature calcination 2 o 3 , the same process requires high-temperature calcination (calcination temperature 600 ~ 800 ℃), there are relatively high equipment investment and energy consumption shortcomings, in addition to the purity of iron oxide produced by this method is only above 98.3%, and there is no coloring power to iron oxide And the uniformity of color and the distribution of particle size are not described