Resource recycling and wastewater treatment method for manganese in mine acid wastewater

Abstract

The invention belongs to the field of wastewater treatment, and particularly relates to a resource recycling and wastewater treatment system for manganese in mine acid wastewater, which is characterized in that the system is formed by sequentially connecting an iron removal system, a 1 # sedimentation tank, a manganese extraction system, a 2 # sedimentation tank, an HDS (high density solid) system and a 3 # sedimentation tank. The solubility of manganese dioxide in a weak acid or weak alkaline aqueous solution is very low, and iron, manganese and other metal ions are effectively separated by adopting a segmented precipitation method, so that the recycling of resources is realized, the hidden danger of secondary pollution caused by waste residues is eliminated, and the treated wastewater reaches the mine discharge standard. The method is simple in process, good in wastewater treatment effect, high in manganese product grade, stable in operation, low in treatment cost, simple in capital construction investment, low in energy consumption and operation cost and wide in application prospect.

Description

Technical Field

[0001] The invention belongs to the field of wastewater treatment, and in particular relates to a method for resource recovery of manganese in acidic mine wastewater and wastewater treatment. Background Art

[0002] A large amount of acidic wastewater can be produced during the mining of mineral resources. Acidic mine wastewater is a special mine wastewater produced during the mining and utilization of sulfur-containing ore bodies. Due to the complex mineral composition of metal ore bodies, the combined action of air, water and sulfate-reducing bacteria can dissolve a variety of heavy metal ions during the mining process, forming acidic wastewater containing heavy metal ions. The characteristics of acidic mine wastewater are: ① low pH value, high content of heavy metal ions; ② large water volume; ③ large fluctuations in water volume and water quality; ④ many discharge points, long duration, scattered discharge locations, seepage, etc. The harmfulness of acidic mine wastewater is determined by its characteristics. Acidic wastewater will have a strong corrosive and destructive effect on mining production equipment. It contains a large amount of heavy metal ions, and its chromaticity and suspended solids are both exceeded. It has toxic side effects on most vegetation. What is more serious is that heavy metals will directly endanger human health through enrichment in the food chain.

[0003] At present, the main methods for treating acid mine wastewater include neutralization precipitation, sulfide precipitation, artificial wetland, adsorption and ion exchange. The neutralization method is to add a neutralizing agent to the acidic wastewater to react with heavy metal ions and hydroxide ions to generate hydroxide precipitates that are insoluble in water, so that the wastewater is neutralized and purified and meets the discharge standards. The neutralization method is a relatively mature method. At present, lime or limestone is usually used as a neutralizing agent in China. It has the advantages of low cost, simple operation and convenient management. However, a large amount of calcium sulfate slag is generated after treatment, and metal hydroxides are prone to cause secondary pollution. The sulfide precipitation method is to add a sulfiding agent (Na2CO3) to the wastewater. 2 S, NaHS, etc.), which converts heavy metal ions in acidic wastewater into insoluble metal sulfide precipitation. The sulfiding agent remains in the water, and the excess sulfur and certain heavy metal ions will form water-soluble complex ions, which will reduce the treatment effect. 2 SO 4 When it comes into contact with acids, harmful hydrogen sulfide gas will be produced, causing air pollution and harming the human body. Ion adsorption is a more economical method because the adsorption method is reversible and the adsorbent can be reused through appropriate desorption. The advantage of the adsorption method is that there are many types of adsorbents and a wide range of sources, but the treatment efficiency is low and the effect is unsatisfactory. Summary of the invention

[0004] The invention discloses a method for resource recovery of manganese in acidic mine wastewater and wastewater treatment, so as to solve any of the above and other potential problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides a technical solution: a method for resource recovery of manganese in acid mine wastewater, which specifically includes the following steps:

[0006] S1) adding a certain amount of hydrogen peroxide, sodium hydroxide and F-1 flocculant to the acidic wastewater to be treated, performing flocculation to remove iron, and obtaining a supernatant and iron slag;

[0007] S2) adding a certain amount of RM-1 manganese extraction agent and F-1 flocculant to the supernatant of S1) to perform flocculation to extract manganese, thereby obtaining a supernatant and manganese slag.

[0008] Furthermore, the resource recovery method also includes S3) wastewater treatment: the supernatant is mixed with a certain amount of calcium oxide and F-2 flocculant for flocculation and precipitation to obtain a supernatant that directly meets the discharge standards.

[0009] Furthermore, the acidic wastewater in S1) is wastewater generated by seepage from the spoil dump and the mineral processing process, with a ferrous iron concentration of 100-4000 mg / L, a manganese concentration of 50-2000 mg / L, and contains varying amounts of calcium, zinc, magnesium ions and a large amount of sulfate ions.

[0010] Further, the specific process parameters in S1) are: the amount of hydrogen peroxide added is V 过氧化氢(L) :m 亚铁(kg) =0.5~0.8: After stirring for 10~20min, stirring speed is 50~100r / min, then add sodium hydroxide solution to adjust pH to 3.5~4.0, continue stirring for 20~30min, stirring speed is 50~100r / min, then add F-1 flocculant After stirring for 1 to 5 minutes and standing for at least 4 hours, a supernatant and iron slag are obtained.

[0011] Furthermore, the F-1 flocculant is an anionic polyacrylamide solution with a molecular weight of 10 million and a mass percent concentration of 0.1%.

[0012] Further, the specific process parameters in S1) are: adding RM-1 manganese extracting agent m RM-1(L) :m 锰(kg) =0.35~0.75, stir for 30~45min, add F-1 flocculant After stirring for 1 to 5 minutes and standing for at least 4 hours, the supernatant overflows into the HDS system and the precipitate is separated into solid and liquid using a high-efficiency filter press.

[0013] Furthermore, the RM-1 manganese extraction agent is a potassium salt oxidant with a mass percentage concentration of 5%.

[0014] Further, the specific process parameters in S3) are: the amount of calcium oxide added is 10-40 kg / m 3 After stirring for 30 to 45 minutes, the amount of F-2 flocculant added is Stir for 1 to 5 minutes and leave for at least 4 hours.

[0015] Furthermore, the F-2 flocculant is a cationic polyacrylamide solution with a molecular weight of 16 million and a mass percent concentration of 0.1%.

[0016] Furthermore, the manganese content in the manganese slag obtained in the resource recovery method is 58%, and the recovery rate reaches 95.8%.

[0017] Beneficial effects of the present invention: Due to the adoption of the above technical scheme, the present invention realizes high-grade recovery of metallic manganese by effectively separating iron, manganese, calcium and magnesium in wastewater, which effectively utilizes resources on the one hand and eliminates the hidden danger of secondary pollution caused by waste residue on the other hand. The present invention has simple process, good wastewater treatment effect and stable operation. The present invention has low treatment cost, small capital construction investment, low energy consumption and low operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a flow chart of a method for resource recovery of manganese in acid mine wastewater and wastewater treatment. DETAILED DESCRIPTION

[0019] To further describe the present invention, the following takes acid wastewater from a mine as a treatment object and further illustrates the technical solution of the present invention in combination with the accompanying drawings and embodiments.

[0020] In view of the shortcomings of the current treatment of acidic wastewater in a metal mine, based on the differences in the precipitation of metal ions at different pH values ​​and the specificity of low solubility of metallic manganese in the form of manganese oxide under weak acid and weak alkaline conditions, a staged precipitation method was used to effectively separate iron, manganese and other metal ions. A process system was developed that can not only eliminate pollution from acidic mine wastewater, but also recover valuable metallic manganese in the wastewater with high quality, eliminating the hidden danger of secondary pollution of waste slag and reducing production costs.

[0021] A method for recycling manganese in acidic mine wastewater and treating wastewater, the system used in the method

[0022] It is composed of an iron removal system, a No. 1 sedimentation tank, a manganese extraction system, a No. 2 sedimentation tank, a HDS system, and a No. 3 sedimentation tank connected in sequence. The water inlet of the iron removal system is used as the water inlet for introducing the treated acidic mine wastewater, and the water outlet of the No. 3 sedimentation tank is used as the outlet for the treated clean water to directly enter the local river. Figure 1 shown.

[0023] The iron removal system is composed of an iron removal tank, a sedimentation tank, a filter press, and an iron slag collection tank. First, 30% hydrogen peroxide is added to the iron removal tank, and after stirring for 10 to 20 minutes (at a speed of 50 to 100 r / min), 30% sodium hydroxide solution is added to adjust the pH to 3.5 to 4.0, and stirring is continued for 20 to 30 minutes (at a speed of 50 to 100 r / min). Then, F-1 flocculant is added, and stirring is performed for 1 to 5 minutes (at a speed of 50 to 100 r / min). The mixture enters the No. 1 sedimentation tank, stays for 4 hours, and the supernatant overflows to the manganese extraction system. The precipitate is separated into solid and liquid by a high-efficiency filter press, and the effluent from the filter press also enters the manganese extraction system.

[0024] The manganese extraction system consists of a manganese extraction tank, a sedimentation tank, a filter press, and a manganese product collection tank. First, RM-1 manganese extraction agent is added to the manganese extraction tank, and after stirring for 30 to 45 minutes (at a speed of 50 to 100 r / min), F-1 flocculant is added, and stirred for 1 to 5 minutes (at a speed of 50 to 100 r / min), and then enters the 2# sedimentation tank. After staying for 4 hours, the supernatant overflows to the HDS system, and the sedimentation adopts a high-efficiency filter press to achieve solid-liquid separation, and the effluent from the filter press also enters the HDS system;

[0025] The HDS system consists of an HDS reaction tank, a sedimentation tank, a filter press, and a waste residue collection tank. First, calcium oxide is added to the HDS tank, and after stirring for 30 to 45 minutes (at a speed of 50 to 100 r / min), F-2 flocculant is added, and stirred for 1 to 5 minutes (at a speed of 50 to 100 r / min). The mixture enters the 3# sedimentation tank, stays for 4 hours, and the supernatant is directly discharged into the local river channel in compliance with the standards. The sedimentation is separated into solid and liquid by a high-efficiency filter press, and the effluent from the filter press enters the HDS system again.

[0026] The F-1 flocculant is an anionic polyacrylamide solution with a molecular weight of 10 million and a mass percent concentration of 0.1%;

[0027] The F-2 flocculant is a cationic polyacrylamide solution with a molecular weight of 16 million and a mass percent concentration of 0.1%;

[0028] The RM-1 manganese extraction agent is a potassium salt oxidant with a mass percentage concentration of 5%.

[0029] The pH value of the mine wastewater is 3.2, and the other components and contents are shown in Table 1 below:

[0030] Table 1 Water quality of acid mine wastewater from a copper mine

[0031]

[0032] Implementation Case 1

[0033] 1. Acidic mine wastewater is 1m3 / h flow rate into the reaction tank 1, 2L / h added to the reaction tank 1 with a content of 30% hydrogen peroxide, the stirring speed is 75r / min, after a residence time of 15min, the water in the reaction tank 1 flows by gravity into the reaction tank 2, 30% sodium hydroxide solution is added to the reaction tank 2 to adjust the pH to 4.0, the stirring speed is 75r / min, after a residence time of 30min, the water in the reaction tank 2 flows by gravity into the flocculation tank 1, 0.1% F-1 flocculant is added to the flocculation tank 1 at a rate of 5L / h, the stirring speed is 75r / min, after a residence time of 2min, the water in the flocculation tank 1 flows by gravity into the sedimentation tank 1, after a residence time of 4h, the supernatant overflows to the manganese extraction system, the bottom precipitate uses a high-efficiency filter press to achieve solid-liquid separation, and the effluent from the filter press also enters the manganese extraction system reaction tank 3, and the iron slag is transported to the designated location of the mine.

[0034] 2. Add 5% RM-1 manganese extracting agent to reaction tank 3 at 140L / h, stirring speed is 75r / min, after residence time 30min, water in reaction tank 3 flows into flocculation tank 2 by gravity, add 0.1% F-1 flocculant to flocculation tank 2 at 3L / h, stirring speed is 75r / min, after residence time 2min, water in flocculation tank 2 flows into sedimentation tank 2 by gravity, after residence time 4h, supernatant overflows to HDS system, and the bottom sediment is separated by solid-liquid separation by high-efficiency filter press, and the effluent of filter press also enters HDS system reaction tank 4, and manganese slag is transported to the warehouse. ; 3. Add lime slurry to the reaction tank 4 to adjust the pH to 8.0, stir at a speed of 75r / min, and after a residence time of 30min, the water in the reaction tank 4 flows by gravity into the flocculation tank 3, add 0.1% F-2 flocculant to the flocculation tank 3 at 2.5L / h, stir at a speed of 75r / min, and after a residence time of 2min, the water in the flocculation tank 3 flows by gravity into the sedimentation tank 3, and after a residence time of 4h, the supernatant overflows and is directly discharged into the local river. The bottom sedimentation is separated by a high-efficiency filter press to achieve solid-liquid separation, and the effluent from the filter press enters the HDS system again, and the waste residue is transported to the designated location of the mine.

[0035] The manganese content in the recovered manganese slag was determined to be 58%, and the recovery rate reached 95.8%.

[0036] The water treated by the HDS system meets the mine drainage discharge standards.

[0037] The above is a detailed introduction to a method for resource recovery of manganese in acid mine wastewater and wastewater treatment provided by the embodiment of the present application. The description of the above embodiment is only used to help understand the method and its core idea of ​​the present application; at the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0038] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0039] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0040] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0041] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A method for recycling manganese from acid mine wastewater, characterized in that: The resource recovery method specifically comprises the following steps: S1) adding a certain amount of hydrogen peroxide, sodium hydroxide and F-1 flocculant to the acidic wastewater to be treated, performing flocculation to remove iron, and obtaining a supernatant and iron slag; S2) adding a certain amount of RM-1 manganese extraction agent and F-1 flocculant to the supernatant of S1) to perform flocculation to extract manganese, thereby obtaining a supernatant and manganese slag.

2. The resource recovery method according to claim 1, characterized in that: The resource recovery method also includes S3) wastewater treatment: the supernatant is mixed with a certain amount of calcium oxide and F-2 flocculant for flocculation and precipitation to obtain a supernatant that directly meets the discharge standards.

3. The resource recovery method according to claim 1, characterized in that: The acidic wastewater in S1) is wastewater generated by seepage from the spoil dump and the ore dressing process, with a ferrous iron concentration of 100-4000 mg / L, a manganese concentration of 50-2000 mg / L, and contains varying amounts of calcium, zinc, magnesium ions and a large amount of sulfate ions.

4. The resource recovery method according to claim 1, characterized in that: The specific process parameters in S1) are: the amount of hydrogen peroxide added is V 过氧化氢(L) :m 亚铁(kg) =0.5~0.8: After stirring for 10~20min, stirring speed is 50~100r / min, then add sodium hydroxide solution to adjust pH to 3.5~4.0, continue stirring for 20~30min, stirring speed is 50~100r / min, then add F-1 flocculant After stirring for 1 to 5 minutes and standing for at least 4 hours, a supernatant and iron slag are obtained.

5. The resource recovery method according to claim 4, characterized in that: The F-1 flocculant is an anionic polyacrylamide solution with a molecular weight of 10 million and a mass percent concentration of 0.1%.

6. The resource recovery method according to claim 1, characterized in that: The specific process parameters in S1) are: adding RM-1 manganese extracting agent m RM-1(L) :m 锰(kg) =0.35~0.75, stir for 30~45min, add F-1 flocculant After stirring for 1 to 5 minutes and standing for at least 4 hours, the supernatant overflows into the HDS system and the precipitate is separated into solid and liquid using a high-efficiency filter press.

7. The resource recovery method according to claim 6, characterized in that: The RM-1 manganese extraction agent is a potassium salt oxidant with a mass percentage concentration of 5%.

8. The resource recovery method according to claim 2, characterized in that: The specific process parameters in S3) are: the amount of calcium oxide added is 10-40 kg / m 3 After stirring for 30 to 45 minutes, the amount of F-2 flocculant added is Stir for 1 to 5 minutes and leave for at least 4 hours.

9. The resource recovery method according to claim 8, characterized in that: The F-2 flocculant is a cationic polyacrylamide solution with a molecular weight of 16 million and a mass percent concentration of 0.1%.

10. The resource recovery method according to claim 8, characterized in that: The manganese content in the manganese slag obtained in the resource recovery method is 58%, and the recovery rate reaches 95.8%.

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