阅读说明：本技术 一种用含铁废料制备掺杂纳米铁酸锌的方法 (Method for preparing doped nano zinc ferrite from iron-containing waste ) 是由 姜艳 李楠 孙丽达 单科 李自静 孙红燕 毛莹博 肖锐敏 于 2019-08-09 设计创作，主要内容包括：本发明公开了一种用含铁废料制备掺杂纳米铁酸锌的方法,属于光催化材料技术领域。其主要特征是以含铁废料为铁源,提取其中的铁以及其他有价元素,制备出光催化性能优于纯纳米铁酸锌的掺杂纳米铁酸锌；不仅解决了二次资源中有价金属元素的有效利用问题,而且制备方法简单、成本低廉,制备的掺杂铁酸锌可有效降解有机废水,达到以废治废的目的,具有很好的应用前景。(The invention discloses a method for preparing doped nano zinc ferrite by using iron-containing waste, belonging to the technical field of photocatalytic materials. The method is mainly characterized in that iron-containing waste is used as an iron source, iron and other valuable elements in the iron source are extracted, and doped nano zinc ferrite with the photocatalytic performance superior to that of pure nano zinc ferrite is prepared; the method not only solves the problem of effective utilization of valuable metal elements in secondary resources, but also has simple preparation method and low cost, and the prepared doped zinc ferrite can effectively degrade organic wastewater to achieve the purpose of treating wastes with processes of wastes against one another, thereby having good application prospect.)

1. a method for preparing doped nano zinc ferrite by using iron-containing waste materials is characterized by comprising the following steps: the method comprises the following steps:

(1) Grinding industrial iron-containing waste into powder with the particle size of below 200 meshes, leaching for 1-3 hours at 50-90 ℃ by using dilute sulfuric acid, dilute hydrochloric acid or dilute nitric acid, extracting iron and other valuable elements in waste residues, filtering to obtain filtrate, and adding a proper amount of hydrogen peroxide into the filtrate to enable Fe in the filtrate to be Fe²⁺Oxidation to Fe³⁺；

(2) Diluting the leachate to control Fe therein³⁺Adjusting the pH of the solution to 0.01 to 0.1mol/L with diluted ammonia water or sodium hydroxide or potassium hydroxide solution to 5 to 10 to precipitate Fe (OH) from the diluted leachate₃The precipitate which is the main is filtered and washed;

(3) Dissolving the precipitate with organic acid solution at 60 deg.C, adding certain amount of zinc oxide powder, completely dissolving the solid material, evaporating water at a temperature not higher than 60 deg.C to form colloidal substance as precursor for preparing nanometer zinc ferrite;

(4) and (4) calcining the precursor obtained in the step (3) at 500-700 ℃ for 1-3 h to obtain the doped nano zinc ferrite powder.

2. The method for preparing doped nano zinc ferrite from iron-containing waste material according to claim 1, wherein the method comprises the following steps: the organic acid is citric acid, tartaric acid, etc., and the organic acid and Fe in the leaching solution³⁺The molar ratio of (A) to (B) is 1.5-4: 1.

3. The method for preparing doped nano zinc ferrite from iron-containing waste material according to claim 1, wherein the method comprises the following steps: the zinc oxide is industrial zinc oxide, and the zinc oxide and Fe in the leaching solution³⁺in a molar ratio of 1: 2.

4. The method for preparing doped nano zinc ferrite from iron-containing waste material according to claim 1, wherein the method comprises the following steps: the types and doping amounts of the doping elements can be adjusted by changing the pH value of the leachate, and when the pH value of the leachate is adjusted to be between 7 and 10, the obtained precipitation-prepared doped nano zinc ferrite has the best photocatalytic effect, and the photocatalytic effect is superior to that of pure zinc ferrite powder.

Technical Field

the invention relates to the field of photocatalytic degradation of organic wastewater, in particular to a method for preparing doped nano zinc ferrite by using iron-containing waste.

background

With the decreasing of metallurgical mineral resources, the comprehensive utilization of metallurgical secondary resources is increasingly emphasized. The wet zinc smelting rotary kiln slag contains a large amount of iron and a small amount of valuable metal elements such as Al, Ti, Cu and the like, is a good secondary resource, and is easy to cause heavy metal pollution of soil or water resources if accumulated in the open air. At present, researches on recycling of the iron-containing waste mainly focus on how to recycle certain element, such as recovering zinc from cloth bag dust with high zinc content by adopting a rotary kiln volatilization mode; extracting copper from the wet-process zinc smelting rotary kiln slag by adopting an acid leaching mode; the research or the technology has the characteristic that a certain valuable element in the waste residue is recovered, but the valuable element in the waste material cannot be comprehensively recovered.

At present, a great deal of research shows that the photocatalytic performance of nano zinc ferrite can be effectively improved by doping other metal elements, but the price of a reagent for doping is higher, and the economic cost can be effectively reduced by extracting the doping elements while extracting iron from waste materials.

Disclosure of Invention

The invention aims to solve the problems and provide a method for preparing doped nano zinc ferrite by using iron-containing waste. The iron-containing waste is used as an iron source to prepare the nano zinc ferrite, and other elements are extracted from the iron-containing waste for doping to prepare the doped nano zinc ferrite, wherein the photocatalytic performance of the doped nano zinc ferrite is superior to that of pure nano zinc ferrite. The method disclosed by the invention comprehensively recycles valuable elements in the iron-containing waste, and prepares the nano zinc ferrite powder with excellent photocatalytic performance at lower cost.

The invention realizes the purpose through the following technical scheme:

The method for preparing the photocatalytic nano zinc ferrite by using the iron-containing waste material comprises the following steps:

(1) Grinding industrial iron-containing waste into powder with the particle size of below-200 meshes, leaching for 1-3 hours at 50-90 ℃ by using dilute sulfuric acid, dilute hydrochloric acid or dilute nitric acid, extracting iron and other valuable elements in waste residues, filtering to obtain filtrate, and adding a proper amount of hydrogen peroxide into the filtrate to enable Fe in the filtrate to be Fe²⁺oxidation to Fe³⁺；

(2) Diluting the leach liquor to control Fe therein³⁺adjusting the pH of the solution to 0.01 to 0.1mol/L with diluted ammonia water or sodium hydroxide or potassium hydroxide solution to 5 to 10 to precipitate Fe (OH) from the diluted leachate₃The precipitate which is the main is filtered and washed;

(3) Dissolving the precipitate with organic acid solution at 60 deg.C, adding certain amount of industrial zinc oxide powder, completely dissolving the solid material, evaporating water at a temperature not higher than 60 deg.C to form colloidal substance as precursor for preparing nanometer zinc ferrite;

(4) And (4) calcining the precursor obtained in the step (3) at 500-700 ℃ for 1-3 h to obtain the doped nano zinc ferrite powder.

The iron-containing waste in the step (1) is wet zinc smelting rotary kiln slag or blast furnace bag dust, and is waste mainly containing iron and other metal elements. The iron-containing waste material is selected as an iron source, so that the cost can be reduced. When the iron in the iron-containing waste is extracted, other metal elements in the iron-containing waste are extracted to be used as doping elements, so that the use of higher-price doping reagents is avoided.

Step (2) adjusting Fe³⁺the concentration of 0.01-0.1 mol/L can assist in controlling the amount of other metal elements except iron entering the precipitate. Adjusting the pH value of the leaching solution to be between 5 and 10 is an important measure for controlling the types of the doping elements. When the pH value of the leaching solution is adjusted to be lower than 5, the doping element is mainly Al, but the doping amount is less, so that the improvement is realizedthe photocatalytic performance effect of the nano zinc ferrite is not obvious, even the photocatalytic effect is slightly reduced; when the pH value of the leachate is adjusted to be higher than 10, the doping elements cover Al, Si, Ti, Zn, Cu, Ca, Mn and other elements, although the doping elements are various, the synergistic effect is facilitated, and the photocatalytic effect of the catalyst is improved, under the pH value, the doping amount of impurity elements is too much, and the photocatalytic performance of the catalyst is reduced; when the pH value of the leachate is adjusted to be between 7 and 9, the doping elements mainly comprise Al, Si, Ti, Zn and Cu, and when the pH value of the leachate is adjusted to be between 9 and 10, the doping elements mainly comprise Al, Si, Ti, Zn, Cu, Ca and Mn, so that the doping amount of impurity elements is more suitable, and the photocatalysis effect of the catalyst is optimal.

in the step (3), Fe is removed from the leaching solution³⁺Other metal ions are contained in the leaching solution, and in order to fully dissolve precipitates, organic acid and Fe in the leaching solution³⁺The molar ratio of the organic acid to the iron ions is more than 1.5, and the proper increase of the molar ratio of the organic acid to the iron ions is beneficial to refining the nano zinc ferrite and enhancing the photocatalytic performance of the nano zinc ferrite. Added industrial zinc oxide powder and Fe in leaching solution³⁺The molar ratio of (1: 2) is 1:2, in the material dissolving process, heating to 60 ℃ is beneficial to dissolving solid in organic acid, when the heating temperature is too high, the decomposition of the organic acid is easy to cause, and when the heating temperature is too low, the dissolving speed is slow, and the precipitate is not easy to completely dissolve. If the precipitate can not be completely dissolved, the particle size of the nano zinc ferrite can be influenced, so that the particle size of the catalyst becomes coarse, and the photocatalytic effect becomes poor. The water is evaporated at a temperature not exceeding 60 c in order to prevent decomposition of organic matter during the evaporation of water.

In the step (4), the calcination temperature should be kept at 500-700 ℃, and the formation of nano zinc ferrite is not facilitated by too low temperature, but the growth of crystal grains is easily caused by too high calcination temperature, and the improvement of the photocatalytic performance of nano zinc ferrite is not facilitated.

The invention has the beneficial effects that:

the invention relates to a method for preparing doped nano zinc ferrite by using iron-containing waste, which is compared with the prior art, aims at solving the problems that the iron-containing waste is used as a secondary resource and is accumulated in a large quantity to cause waste, and some iron-containing waste contains heavy metal ions to pollute the environment, and valuable elements in the iron-containing waste cannot be effectively utilized in the prior art, uses the iron-containing waste as an iron source, extracts iron and other valuable elements in the iron-containing waste to prepare the doped nano zinc ferrite with photocatalytic performance superior to that of pure nano zinc ferrite, is used for photocatalytic degradation of organic wastewater, and achieves the aim of treating waste by waste. A large number of researches show that the photocatalytic effect of nano zinc ferrite can be effectively improved by doping other metal elements, however, the reagent for doping is usually high in price, and the cost can be effectively controlled by extracting the doping elements while extracting iron from waste materials.

The iron-containing waste is taken as an iron source, and other metal elements in the iron-containing waste are extracted to be taken as doping elements, so that the preparation cost of the doped nano zinc ferrite can be effectively reduced;

The method has the advantages of environmental protection, and firstly, the problem that the iron-containing waste pollutes the environment is solved; secondly, the nano zinc ferrite prepared by the waste has excellent photocatalytic performance and can be used for photocatalytic degradation of organic matters;

The variety and the doping amount of the doping elements can be adjusted by changing the pH value of the leaching solution, so that the prepared doped nano zinc ferrite has the best photocatalytic performance.

drawings

FIG. 1 is an XRD diagram of nano zinc ferrite powders prepared in examples 1, 2, 3 and 4;

Fig. 2 shows the degradation rate of methyl orange photo-catalytically degraded by nano zinc ferrite powder prepared in examples 1, 2, 3 and 4.

Detailed Description

The invention is further illustrated below: