阅读说明：本技术 一种改性电解二氧化锰废渣催化剂及其制备方法和应用 (Modified electrolytic manganese dioxide waste residue catalyst and preparation method and application thereof ) 是由 贺治国 李梦珂 钟慧 胡亮 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种改性电解二氧化锰废渣催化剂及其制备方法和应用。将电解锰渣进行煅烧后,采用酸溶液进行浸渍,即得改性电解二氧化锰废渣催化剂。该催化剂能在宽pH范围内催化双氧水或过硫酸盐快速、高效氧化去除水体中抗生素、染料和选矿废水中浮选药剂,且该催化剂的制备方法以冶金废渣为原料,成本低,制备过程简单,具有较好生产和应用前景。(The invention discloses a modified electrolytic manganese dioxide waste residue catalyst and a preparation method and application thereof. Calcining the electrolytic manganese slag, and then soaking the electrolytic manganese slag by adopting an acid solution to obtain the modified electrolytic manganese dioxide waste slag catalyst. The catalyst can catalyze hydrogen peroxide or persulfate within a wide pH range to quickly and efficiently oxidize and remove antibiotics and dyes in water and flotation reagents in mineral processing wastewater, and the preparation method of the catalyst takes metallurgical waste residues as raw materials, is low in cost, simple in preparation process and has good production and application prospects.)

1. A preparation method of a modified electrolytic manganese dioxide waste residue catalyst is characterized by comprising the following steps: calcining the electrolytic manganese slag, and then soaking the electrolytic manganese slag by adopting an acid solution to obtain the electrolytic manganese slag.

2. The method for preparing the modified electrolytic manganese dioxide waste residue catalyst according to claim 1, wherein the method comprises the following steps: the calcining conditions are as follows: the temperature is 400-800 ℃, and the time is 1-2 h.

3. The method for preparing the modified electrolytic manganese dioxide waste residue catalyst according to claim 1, wherein the method comprises the following steps: the acid solution is an inorganic acid solution and/or an organic acid solution.

4. The method for preparing the modified electrolytic manganese dioxide waste residue catalyst according to claim 1 or 3, characterized in that:

the concentration of the inorganic acid solution is 0.3-0.5M;

the concentration of the organic acid solution is 4-6 g/L;

the inorganic acid solution comprises at least one of hydrochloric acid, sulfuric acid and nitric acid;

the organic acid solution comprises a citric acid solution and/or a salicylic acid solution.

5. The method for preparing the modified electrolytic manganese dioxide waste residue catalyst according to claim 1, wherein the method comprises the following steps: the impregnation conditions are as follows: the temperature is 55-60 ℃, and the time is 30-40 min.

6. A modified electrolytic manganese dioxide waste residue catalyst is characterized in that: the preparation method of any one of claims 1 to 5.

7. The use of the modified electrolytic manganese dioxide waste residue of claim 6, wherein: the method is applied to catalyzing hydrogen peroxide and/or persulfate to oxidize and degrade organic wastewater.

8. The use of the modified electrolytic manganese dioxide waste residue according to claim 7, wherein: the organic wastewater comprises at least one of antibiotic wastewater, dye wastewater and mineral processing wastewater containing a flotation reagent.

9. The use of the modified electrolytic manganese dioxide waste residue according to claim 7, wherein: the pH range of the organic wastewater is 3-9.

10. The use of the modified electrolytic manganese dioxide waste residue according to claim 7, wherein: the adding concentration of the modified electrolytic manganese dioxide waste residue catalyst in the organic wastewater is 0.4-0.8 g/L;

the adding concentration of the hydrogen peroxide and/or the persulfate in the organic wastewater is 0.1-0.7 g/L.

Technical Field

The invention relates to an oxidation catalytic material, in particular to a catalytic material prepared by utilizing waste residues generated in the process of producing electrolytic manganese dioxide, and also relates to a method for activating hydrogen peroxide or persulfate to oxidize and degrade organic wastewater by utilizing an electrolytic manganese dioxide waste residue catalyst, belonging to the technical field of electrolytic manganese residue resource utilization.

Background

Transition metal oxides such as Fe₂O₃、Co₃O₄、CuFeO₂And the like are the most commonly used Advanced Oxidation (AOPs) catalysts, which are highly effective in activating oxidants such as hydrogen peroxide (H)₂O₂) Permonosulfate (KHSO)₅)、Peroxodisulfate (K)₂S₂O₈) And generates a large amount of Reactive Oxygen Species (ROS), thereby degrading organic pollutants in the wastewater. However, the catalyst is complicated to prepare, high in cost, easy to leach metal ions, and used for activating H₂O₂The pH is less than 3.0, and the like, thereby limiting the development.

China is the largest electrolytic manganese metal producing country in the world, and the generation of a large amount of electrolytic manganese slag is a serious problem in the electrolytic manganese industry, the annual production amount of the electrolytic manganese slag is about 2000 tons, and the current accumulated stock amount exceeds 8000 tons. Therefore, the treatment and disposal of the electrolytic manganese slag are particularly urgent. The electrolytic manganese slag is prepared into the high value-added material with catalytic performance, and is an effective way for reducing the harm of the manganese slag. However, the manganese slag often contains impurities (such as calcium, magnesium and other compounds) on the surface, and the content of useful components (such as iron, manganese oxides and the like) is not high and is difficult to be directly utilized, so that proper modification is needed before use. At present, a plurality of researches report the preparation or application of the modified electrolytic manganese slag-based catalyst, but some problems still exist, such as the preparation method of the modified manganese slag-jarosite slag catalyst developed by Chinese patent (CN 110449162B), although the flow is short and the operation is simple and convenient, the calcium carbonate grown in situ is not beneficial to the activation of persulfate; chinese patent (CN 108273516B) utilizes modified manganese slag to activate hydrogen peroxide to degrade methylene blue, but a copper-cerium mixed solution needs to be added in the manganese slag modification process, so that the material preparation cost is increased; while the Chinese patent (CN 110092438A) prepares the photocatalyst by utilizing the electrolytic manganese slag, although the preparation process is simple and no exogenous compound is needed to be added, the photocatalyst strongly depends on a light source and is difficult to realize industrial application.

Disclosure of Invention

In view of the above technical problems in the prior art, a first object of the present invention is to provide a modified electrolytic manganese dioxide waste residue catalyst, which has a high catalytic activity on hydrogen peroxide or persulfate, and can improve the degradation efficiency of hydrogen peroxide or persulfate on organic matters.

The second purpose of the invention is to provide a method for preparing the modified electrolytic manganese dioxide waste residue catalyst, which takes the electrolytic waste residue generated in the production of electrolytic manganese dioxide as a raw material, has low cost and simple steps, only needs one-step calcination and impurity removal treatment, and is beneficial to large-scale production.

The third purpose of the invention is to provide an application of the modified electrolytic manganese dioxide waste residue catalyst, the modified electrolytic manganese dioxide waste residue catalyst is applied to catalyzing oxydol and persulfate to oxidize and degrade antibiotic wastewater, dye wastewater or mineral processing wastewater containing a flotation reagent, the fast and efficient degradation of refractory organic matters such as antibiotic, dye and flotation reagent can be realized, the pH range of the catalyst is wide, the catalyst shows high catalytic activity at room temperature, and the catalyst is beneficial to large-scale popularization and application.

In order to achieve the technical purpose, the invention provides a preparation method of a modified electrolytic manganese dioxide waste residue catalyst, which comprises the steps of calcining electrolytic manganese residues, and then soaking the calcined electrolytic manganese residues by using an acid solution to obtain the modified electrolytic manganese dioxide waste residue catalyst.

The technical scheme of the invention uses single electrolytic manganese slag as a raw material, the raw material of the electrolytic manganese slag contains a small amount of components with catalytic activity such as FeOOH and the like, but the active components are wrapped by gangue minerals such as gypsum, quartz and the like, and meanwhile, the electrolytic manganese slag also contains a large amount of useful metal elements such as iron, manganese and the like, but does not exist as mineral phase components with catalytic activity, so that the catalytic activity of the whole electrolytic manganese slag is relatively low, the mineral phase components of the electrolytic manganese slag are shown in figure 1, and the catalytic activity is shown in figure 2. The technical scheme of the invention is that firstly, gypsum without catalytic activity in electrolytic manganese slag is converted into CaSO by adopting a high-temperature calcination mode₄And the mineral containing iron, manganese and the like without catalytic activity is converted into Fe with catalytic activity at high temperature₂O₃And (Fe)_0.67Mn_0.33) OOH and other main components, and the active components are dispersed and loaded on the surface of stable silicon dioxide, and on the basis, soluble impurities in the composite material and calcium sulfate and the like coated on the surface of the active components are removed by dipping with an acid solution, and meanwhile, the catalytic activity of the active components is improved, so that more active sites can be exposed, and the catalytic activity of the manganese slag is greatly improved.

As a preferred embodiment, the calcination conditions are: the temperature is 400-800 ℃, and the time is 1-2 h. The more preferable temperature is 600 to 800 ℃. If the calcination temperature is too low, it becomes difficult to convert the metal minerals such as iron and manganese into Fe having catalytic activity₂O₃FeOOH and (Fe)_0.67Mn_0.33) OOH and the like, and simultaneously cannot fully convert gypsum and the like; when the calcining temperature is too high, the catalytic activity of the manganese slag cannot be further improved, and the energy consumption is increased.

As a preferred embodiment, the acid solution is an inorganic acid solution and/or an organic acid solution.

As a preferable scheme, the concentration of the inorganic acid solution is 0.3-0.5M; the inorganic acid solution comprises at least one of hydrochloric acid, sulfuric acid and nitric acid.

As a preferable scheme, the concentration of the organic acid solution is 4-6 g/L; the organic acid solution comprises a citric acid solution and/or a salicylic acid solution.

As a preferred embodiment, the acid solution is most preferably citric acid. The adoption of organic acid can ensure the removal of impurities and can not damage the crystal structure of the active ingredients.

As a preferred embodiment, the impregnation conditions are: the temperature is 55-60 ℃, and the time is 30-40 min.

The electrolytic manganese slag is pretreated as follows: cleaning and drying with water, and sieving with a 150-200 mesh sieve.

The invention also provides a modified electrolytic manganese dioxide waste residue catalyst which is obtained by the preparation method.

The invention also provides application of the modified electrolytic manganese dioxide waste residue in catalyzing hydrogen peroxide and/or persulfate to oxidize and degrade organic wastewater. The persulfate is selected from potassium monopersulfate and/or potassium peroxodisulfate.

As a preferred embodiment, the organic wastewater includes at least one of antibiotic wastewater, dye wastewater and beneficiation wastewater containing a flotation agent. The antibiotic is specifically tetracycline, carbamazepine, levofloxacin, etc., the dye is methyl orange, rhodamine B, methyl blue, etc., and the flotation agent is second oil, ester-200, etc.

As a preferable scheme, the pH value of the organic wastewater is 3-9. The modified electrolytic manganese dioxide waste residue catalyst has better catalytic activity in a higher pH range, and solves the problem that the existing catalyst catalyzes and activates H₂O₂The oxidizing agent needs to be carried out under the condition that the pH value is less than 3.0.

As a preferable scheme, the adding concentration of the modified electrolytic manganese dioxide waste residue catalyst in the organic wastewater is 0.4-0.8 g/L; the adding concentration of the hydrogen peroxide and/or the persulfate in the organic wastewater is 0.1-0.7 g/L.

As a preferable scheme, the organic wastewater contains one or more of antibiotics, dyes and flotation reagents. Generally, the concentration of the antibiotic is 5-20 mg/L, the concentration of the dye is 100-200 mg/L, and the COD of the beneficiation wastewater is 150-250 mg/L.

For the organic wastewater in the concentration range, a modified electrolytic manganese dioxide waste residue catalyst is adopted, and the adding concentration of the electrolytic manganese dioxide waste residue catalyst in the organic wastewater is 0.4-0.8 g/L; the adding concentration of hydrogen peroxide and/or persulfate in the organic wastewater is 0.1-0.7 g/L; within 60-80 min, the removal rate of antibiotics is 55-85%, the removal rate of dyes is 85-100%, and the removal rate of COD of mineral processing wastewater reaches 40-88%.

The invention provides a preparation method of a modified electrolytic manganese dioxide waste residue catalyst, which comprises the following steps:

step 1) washing electrolytic manganese dioxide waste residues with water for 1-2 times, drying at 50-60 ℃ for 5-8 h, sieving the dried waste residues with a 150-200-mesh sieve, and collecting the waste residues under the sieve for later use;

step 2) placing the undersize waste residue obtained in the step 1) into a muffle furnace, heating to 400-800 ℃ at a heating rate of 5-8 ℃/min, and roasting for 1-2 h;

step 3) adding the roasted waste residue obtained in the step 2) into a solution containing nitric acid and/or hydrochloric acid, or citric acid and/or salicylic acid for re-modification, wherein the concentration of an inorganic acid solution is 0.3-0.5M, the concentration of an organic acid solution is 4-6 g/L, and continuously stirring and reacting for 30-40 min at the constant temperature of 55-60 ℃;

and 4) carrying out suction filtration on the solution reacted in the step 3), wherein the obtained filter residue is the modified electrolytic manganese dioxide waste residue catalyst.

The process of the modified electrolytic manganese dioxide waste residue catalyst used for removing the flotation reagent in the beneficiation wastewater comprises the following steps: adding the modified electrolytic manganese dioxide waste residue catalyst into the wastewater according to 0.4-0.8 g/L, simultaneously controlling the adding dosage of the oxidant to be 0.1-0.7 g/L, controlling the pH value of the wastewater to be 3-9, and reacting at room temperature. The content of antibiotics in the wastewater is 5-20 mg/L, the concentration of the dye is 100-200 mg/L, and the concentration of COD in the mineral processing wastewater is 150-250 mg/L. The degradation reaction time is 60-80 min, the removal rate of antibiotics is 55-85%, the removal rate of dyes is 85-100%, and the removal rate of COD in the mineral processing wastewater is 40-88%.

Compared with the prior art, the technical scheme of the invention has the following advantages:

1) the modified electrolytic manganese dioxide waste residue catalyst provided by the invention adopts electrolytic manganese residues as main raw materials, is cheap and easy to obtain, realizes efficient resource utilization of harmful solid waste residues, is beneficial to environmental protection, is simple and convenient in modification method, only needs one-step high-temperature calcination and impurity removal process, does not need other chemical substances with catalytic activity in the modification process, directly converts the original complex mineral phase in the waste residues through pre-roasting, and then carries out acid treatment to remove surface adverse components to obtain the catalyst.

2) The modified electrolytic manganese dioxide waste residue catalyst can be used as a high-grade oxidation catalyst for catalyzing oxidants such as hydrogen peroxide, persulfate and the like to efficiently degrade organic wastewater, and has a good application prospect.

3) The modified electrolytic manganese dioxide waste residue catalyst can be used for efficiently and quickly degrading antibiotics, dyes and organic matters in mineral processing wastewater (particularly refractory flotation agents containing No. two oil) and has high catalytic activity on hydrogen peroxide in a wide pH range (3.0-9.0).

Drawings

FIG. 1 shows the electrolytic manganese slag and different temperaturesXRD contrast diagram of modified electrolytic manganese slag after roasting. It can be seen that the main mineral phases of the electrolytic manganese dioxide waste residue are quartz and gypsum, and after roasting, the gypsum mineral phase disappears, and calcium sulfate and hematite (Fe)₂O₃) And manganese iron hydroxide (Fe)_0.67Mn_0.33) The peak of OOH appears and as the firing temperature increases, the phase strength increases; after citric acid treatment, the peak of calcium sulfate disappears, (Fe)_0.67Mn_0.33) OOH and Fe₂O₃The peak intensity of (a) increases.

FIG. 2 is a graph comparing the degradation curves of electrolytic manganese slag and modified electrolytic manganese dioxide slag catalyst prepared in example 1 at different temperatures in combination with a peroxymonosulfate system for No. two oil; due to Fe in the catalyst prepared at 800 DEG C₂O₃FeOOH and (Fe)_0.67Mn_0.33) The content ratio of OOH is the highest (see table 2), so that the manganese slag-800 has higher degradation efficiency under the same experimental conditions; after acid treatment, the surface calcium sulfate is removed, and the catalytic activity is further improved, so that the t-manganese slag 800 has the highest degradation efficiency.

FIG. 3 is a graph comparing the degradation efficiency of modified electrolytic manganese dioxide spent slag catalyst prepared in example 2 in combination with a peroxydisulfate system for several dyes; the result shows that the modified manganese slag catalyst prepared by the method shows excellent removal effect on both anionic dyes and cationic dyes.

FIG. 4 is a graph comparing the COD removal rates of several beneficiation wastewater with the modified electrolytic manganese dioxide spent residue catalyst prepared in example 3 in combination with a peroxymonosulfate system; along with the increase of COD of the actual mineral processing wastewater, the degradation efficiency is reduced and is 80-88%.

FIG. 5 is a graph comparing the degradation of butylamine black drug at different pH values for the modified electrolytic manganese dioxide spent slag catalyst prepared in example 4 in combination with a hydrogen peroxide system. With the increase of the pH value, the degradation efficiency is slightly reduced, and the removal rate of COD in the wastewater of the simulated butylammonium black liquor is still 70.4% when the pH value is 9.0.

Detailed Description

The following examples are intended to further illustrate the present disclosure, but not to limit the scope of the claims.

Example 1

Preparing modified electrolytic manganese dioxide waste residues: manganese slag (obtained from Hunan Tan electrochemical technology Co., Ltd., main element composition shown in Table 1) was washed with water for 2 times, dried at 60 deg.C for 6h, sieved through a 200 mesh sieve, and collected. Respectively weighing 5g of manganese slag, roasting at 400 ℃, 600 ℃ and 800 ℃ for 2h to respectively obtain roasted manganese slag 400, manganese slag 600 and manganese slag 800, respectively adding the manganese slag, the manganese slag and the manganese slag into a citric acid solution containing 4g/L, continuously stirring and modifying at 60 ℃ for 30min, after the reaction is finished, performing suction filtration by using a water system filter membrane of 0.22 mu m, respectively cleaning by using ethanol and deionized water, and drying to obtain modified manganese slag which is respectively t-manganese slag 400, t-manganese slag 600 and t-manganese slag 800. In addition, the unmodified manganese residue (undersize manganese residue) was used directly in the control experiment.

40mg of unmodified manganese slag and 2mL of potassium monopersulfate with the concentration of 10g/L are simultaneously added into No. two oil simulated wastewater with the concentration of 100mg/L and the pH value of 5.4, and the mixture is stirred for 120min at room temperature. Under the same experimental conditions and parameters, the unmodified manganese slag is replaced by 6 modified manganese slag for experiment. After the catalytic reaction was completed, the degradation rates of the second oil in the water samples of the unmodified manganese slag reaction system were measured to be 8.2%, the degradation rates of the second oil in the water samples of the manganese slag 400, the manganese slag 600 and the manganese slag 800 reaction systems were measured to be 39.8%, 46.1% and 53.7%, respectively, and the degradation rates of the second oil in the water samples of the t-manganese slag 400, the t-manganese slag 600 and the t-manganese slag 800 reaction systems were measured to be 49.1%, 65.2% and 77%, respectively, as shown in fig. 2.

Table 1 XRF analysis of electrolytic manganese dioxide dross

TABLE 2 relative content of phases in different materials

N.d indicates failure to detect

Example 2

30mg of t-manganese slag 800 prepared in example 1 and 2mL of potassium monopersulfate with a concentration of 10g/L were added simultaneously to 100mL of simulated dye wastewater containing 100mg/L of rhodamine B, methyl blue and methyl orange respectively and having a pH of 10.5, and the mixture was stirred at room temperature for reaction for 60 min. After the catalytic reaction is completed, the degradation rates of rhodamine B ethyl xanthate, ethidium nitrate, butylamine black compound and second oil are respectively 99.6%, 99.9% and 95.3%, which is shown in figure 3.

Example 3

Several different kinds of mineral processing wastewater are respectively taken from wastewater of a certain ore dressing plant in Hengyang city (the ore dressing plant takes ethylene-sulfur-nitrogen as a collecting agent and takes oil II as a foaming agent), wastewater of a certain ore dressing plant in Chenzhou city (the ore dressing plant takes xanthate and black lead as collecting agents and takes oil II as a foaming agent), wastewater of a certain ore dressing plant in Tanzhou city (the ore dressing plant takes xanthate as a collecting agent and takes oil II as a foaming agent) and wastewater of a certain ore dressing plant in Shaoyang city (the ore dressing plant takes black lead and ethylene-sulfur-nitrogen as collecting agents and takes oil II as a foaming agent), and the water quality conditions are respectively shown in tables 3, 4, 5 and 6(mg/L except pH):

TABLE 3

Parameter(s)	pH	COD	Na	K	Si	S
							Content (wt.)	11.37	156	275	20.6	51	211

TABLE 4

Parameter(s)	pH	COD	Na	K	Si	S	Ca
								Content (wt.)	12.24	208	325	18	58	209	93

TABLE 5

Parameter(s)	pH	COD	Pb	Zn	Na	K	Si	S
									Content (wt.)	11.26	233	26	217	186	23	76	257

TABLE 6

Preparing modified mixed slag: after 20g of clean manganese slag with 150 meshes below the sieve is roasted at 800 ℃ for 2h, the manganese slag is added into 500mL of 6g/L citric acid solution, and the reaction is continued for 40min at 50 ℃. After the reaction is finished, filtering, washing with ethanol and deionized water respectively, and drying for later use.

15mg of modified manganese slag and 2mL of potassium peroxodisulfate with the concentration of 10g/L are simultaneously added into 200mL of the four ore dressing wastewater, and stirred and reacted for 80min at room temperature. After the catalytic reaction is finished, the residual contents of COD in the beneficiation wastewater are respectively measured to be 19.6mg/L, 27.9mg/L, 41.5mg/L and 48.9mg/L, and the removal rates are respectively 87.4%, 86.6%, 82.2% and 80.3%. See fig. 4.

Example 4

Selecting the t-manganese slag 800 prepared in the example 1 as a catalyst, simultaneously adding 20mg of the t-manganese slag 800 and 100 mu L of hydrogen peroxide with the mass fraction of 30 percent into 200mL of simulated mineral processing wastewater containing 100mg/L of butylamine black drug, and using HNO₃And NaOH was added to adjust the pH of the initial solution to 3.0, 5.0, 7.0 and 9.0, respectively, and the reaction was stirred at room temperature for 60 min. After the catalytic reaction was completed, the degradation rates of butylamine black drug were measured to be 86.3%, 75.7%, 72.5% and 70.4%, respectively, as shown in fig. 5.

Example 5

The water sample containing levofloxacin and tetracycline is taken from the wastewater of a pharmaceutical factory in Changsha, and the water quality conditions are shown in Table 7 as follows:

TABLE 7 pharmaceutical wastewater sample Properties

After 20g of clean manganese residue with 150 meshes below the sieve is roasted at 600 ℃ for 1.5h, the manganese residue is added into 500mL of 0.3M nitric acid solution, and the reaction is continued for 30min at 50 ℃. After the reaction is finished, filtering, washing with ethanol and deionized water respectively, and drying for later use.

Adding 20mg of prepared t-manganese slag 600 and 100 mu L of hydrogen peroxide with the mass fraction of 30% into 200mL of pharmaceutical wastewater at the same time, controlling the pH to be 5.6, and stirring and reacting for 60min at room temperature. After the catalytic reaction is finished, the residual contents of the levofloxacin and the tetracycline in the pharmaceutical wastewater are respectively 3.5 mu g/L and 12.6 mu g/L.