CN114394771B - Method for resource utilization of manganese ore slag generated in manganese sulfate production process - Google Patents

Abstract

The invention discloses a method for resource utilization of manganese slag produced in the production process of manganese sulfate, and belongs to the technical field of waste residue resource utilization. The method comprises the following technical steps: (1) acid leaching extraction; (2) mechanical activation; (3) oxidation desulfurization; (4) acid washing desulfurization; (5) light reduction. The method provided by the invention can effectively process the manganese slag produced in the manganese sulfate production process, gradually recover the useful components in the manganese slag, and prepare various high value-added products. The obtained filter residue II can be used as cement raw meal or Portland cement mixed material, filtrate III is returned to the manganese sulfate production system, and the (Fe,Mn)C ₂ O ₄ composite material obtained from filter residue III is used to treat Cr(VI) polluted wastewater, solidify heavy metals in soil, etc., effectively avoiding The waste of resources in manganese slag and the secondary pollution caused by stacking or landfilling of manganese slag are eliminated, so as to achieve the goal of resource utilization and zero discharge of manganese slag, which has good environmental and economic benefits.

Description

A method for resource utilization of manganese slag produced in the production process of manganese sulfate

technical field

The invention belongs to the technical field of resource utilization of waste slag, and in particular relates to a method for resource utilization of manganese slag produced in the production process of manganese sulfate.

Background technique

The main raw materials of manganese slag are natural pyrolusite and pyrite, which are solid wastes produced during the production of manganese sulfate in sulfuric acid medium. my country's natural pyrolusite is mainly low-grade manganese ore, so every ton of manganese sulfate produced will produce about 5-6 tons of manganese slag. Manganese slag contains a certain amount of KFe ₂ (SO ₄ ) ₂ (OH) ₆ , CaSO ₄ ·2H ₂ O, FeS ₂ , SiO ₂ and other metal impurities (Mn, Al, Mg, etc.) value of use.

Direct stockpiling and landfilling of manganese slag has caused a series of problems, including resource waste of valuable components, occupying land, polluting the environment, and increasing production costs of enterprises. Therefore, the impact of manganese slag on the environment and economic benefits has become a problem that requires great attention.

At present, the ways to deal with manganese slag mainly include the preparation of functional materials (such as catalysts and adsorbents) by using manganese slag, high-temperature roasting-magnetic separation, dissolution and recovery of valuable metals (such as iron and manganese) under acidic or alkaline conditions. ) and the use of manganese slag as construction materials (such as concrete, cement and aggregate in road surfaces). However, these methods are difficult to obtain ideal results for a large amount of manganese slag or greatly reduce the utilization value of valuable components, especially in the method of recovering valuable components, only 50% of manganese slag can be effectively treated, and the remaining waste residue It is still dumped in the landfill, causing secondary pollution to the environment. Therefore, it is crucial to adopt appropriate technology to effectively process and utilize manganese slag resources.

Based on the above problems and needs, the present invention provides a new green recycling treatment technology, which can effectively treat the manganese slag produced in the manganese sulfate production process, gradually recover the useful components in the manganese slag, and prepare various high value-added products , in order to achieve good environmental and economic benefits.

Contents of the invention

In view of the above problems, the present invention provides a method for the resource utilization of manganese slag produced in the production process of manganese sulfate. Through the technological process of acid leaching extraction, mechanical activation, oxidation desulfurization, acid washing desulfurization and light reduction, the manganese slag can be made The useful components are gradually recovered and various high value-added products are prepared. The obtained filter residue II can be used as cement raw meal or Portland cement mixed material, the filtrate III is returned to the manganese sulfate production system, and the (Fe, Mn)C ₂ O ₄ composite materials are used to treat Cr(VI) polluted wastewater and solidify soil heavy metals, etc., effectively avoiding the waste of resources in manganese slag, thereby achieving the goal of resource utilization and zero discharge of manganese slag.

The present invention is realized through the following technical solutions:

A method for resource utilization of manganese slag produced in the production process of manganese sulfate, comprising the following steps:

(1) Acid leaching extraction: after heating the H ₂ C ₂ O ₄ solution, add the manganese slag produced in the production process of manganese sulfate, stir evenly, and obtain filtrate I and filter residue I after filtering and washing;

(2) Mechanical activation: add filter residue I and ball milling medium zirconia into a mechanically activated solid-phase reactor for mechanical activation pretreatment to obtain pretreated filter residue I;

(3) Oxidative desulfurization: add the pretreated filter residue I into the H ₂ O ₂ solution for oxidative desulfurization, and add H ₂ SO ₄ solution to maintain the acidic environment;

(4) Acid washing and desulfurization: after the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment, and obtain filtrate II and filter residue II after filtration;

(5) Illumination reduction: Combine filtrate I and filtrate II and perform light reduction. After filtration, filtrate III and filter residue III are obtained. Filter residue III is washed to neutral and dried to obtain (Fe,Mn)C ₂ O ₄ compound material, and the filtrate III is returned to the manganese sulfate production system.

Further, in step (1), the acid leaching extraction is to react for 0.5-3h under the condition of stirring speed of 200-600rpm and temperature of 70-90°C.

Further, in step (1), the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to the manganese slag is 8-15:1.

Further, in step (1), the concentration of the H ₂ C ₂ O ₄ solution is 1-3 mol/L.

Further, in step (2), the volume ratio of the filter residue I to zirconium dioxide is 8-12:1.

Further, in step (2), the mechanical activation is treated at a rotation speed of 350-500 rpm and a temperature of 45-60° C. for 0.5-2 hours.

Further, in step (3), the oxidative desulfurization is to react for 0.5-2h under the conditions of a stirring speed of 200-600rpm and a temperature of 30-50°C.

Further, in step (3), the volume fraction of the H ₂ O ₂ solution is 10-20%.

Further, in step (4), the time for acid washing to remove sulfur is 0.5-2h.

Further, in step (4), the filter residue II is used as cement raw meal or Portland cement mixed material.

Further, in step (5), the light reduction time is 3-4h.

Further, the (Fe,Mn)C ₂ O ₄ composite material is used for treating Cr(VI) polluted wastewater and solidifying soil heavy metals.

Compared with prior art, advantage and beneficial effect of the present invention are:

1. The method provided by the present invention can effectively treat the manganese slag produced in the manganese sulfate production process, gradually recover the useful components in the manganese slag, and prepare various high value-added products. The obtained filter residue II can be used as cement raw meal Or Portland cement mixed material, the filtrate III is returned to the manganese sulfate production system, and the (Fe,Mn)C ₂ O ₄ composite material obtained from the filter residue III is used to treat Cr(VI) polluted wastewater, solidify soil heavy metals, etc., effectively It avoids the waste of resources in manganese slag and the secondary pollution caused by stacking or landfilling of manganese slag, so as to achieve the goal of resource utilization and zero discharge of manganese slag, which has good environmental and economic benefits and is beneficial to the actual industry. Applications.

2. The present invention uses oxalic acid to carry out acid leaching extraction of manganese slag. Oxalic acid has low cost, good complexing ability and high photochemical activity, and can effectively improve the leaching rate of iron in manganese slag. The present invention can make the leaching rate of iron Reached 94.5%.

3. The present invention carries out mechanical activation pretreatment on the filter residue I, and the mechanical activation can cause the minerals in the filter residue I to undergo phase change, structural defects and surface characteristics changes, which can greatly enhance the reactivity of solid particles and achieve the purpose of intensified leaching. And synergistic oxidation desulfurization and acid washing desulfurization to improve the sulfur leaching rate, in this process, S ₂ ^2- is oxidized to SO ₄ ^2- , reducing the sulfur content in the slag, and recovering sulfur in the form of H ₂ SO ₄ Elements, the desulfurization rate can reach 96.19%, and then return to the manganese sulfate production system together with the oxalic acid solution in the filtrate III as a leaching agent and reducing agent for recycling, which further improves the resource utilization of manganese slag.

4. After the process of mechanical activation, oxidative desulfurization and pickling desulfurization, the present invention greatly reduces the sulfur content in the manganese slag, and at the same time, when the filter residue II is used as the Portland cement mixing material, the Portland cement produced can reach GB 175- The 2007 "General Portland Cement" standard (sulfur trioxide content in slag portland cement ≤ 4%) effectively improves the stability of cement, and further improves the resource utilization value of manganese slag, which is beneficial to reduce The cost of cement production has good economic benefits.

5. The present invention can synthesize (Fe,Mn)C ₂ O ₄ composite material in situ through photoreduction, and the (Fe,Mn)C ₂ O ₄ composite material simultaneously contains catalytic manganese, reducing iron and good The electron donor oxalic acid has a good reduction and repair ability for Cr(VI) polluted wastewater, which provides a new way for the treatment of Cr(VI) polluted wastewater. In addition, (Fe,Mn)C ₂ O ₄ composites can also be used to immobilize heavy metals in soil, providing a new way for the control of soil environmental pollution.

Description of drawings

Fig. 1 is a schematic diagram of the process flow of the present invention.

Fig. 2 is the XRD patterns of filter residue I and filter residue II in Example 1 of the present invention.

Fig. 3 is an SEM image of filter residue II in Example 1 of the present invention.

Fig. 4 is a physical picture of filter residue II in Example 1 of the present invention.

Detailed ways

The present invention will be further described in detail through examples below, and these examples are only used to illustrate the present invention, and do not limit the protection scope of the present invention.

Example 1

A method for resource utilization of manganese slag produced in the production process of manganese sulfate, comprising the following steps:

(1) Acid leaching extraction: After heating the H ₂ C ₂ O ₄ solution with a concentration of 3mol/L, add the manganese slag produced in the manganese sulfate production process, and the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to the manganese slag is 10:1, react at a stirring speed of 400rpm and a temperature of 90°C for 2h, obtain filtrate I and filter residue I after filtration and washing, and the XRD pattern of filter residue I is shown in Figure 2;

(2) Mechanical activation: add filter residue I with a volume ratio of 10:1 and ball milling medium zirconia into a mechanical activation solid-phase reactor for mechanical activation pretreatment, and treat for 1 hour at a speed of 400 rpm and a temperature of 50 °C , to obtain the pretreated filter residue I;

(3) Oxidative desulfurization: Add the pretreated filter residue I into _{the H2O2} solution with a volume fraction of 20% for oxidative desulfurization treatment, and add _H2SO4 solution with a concentration of _0.1mol /L to maintain the acidic environment. React for 0.5h at a stirring speed of 400rpm and a temperature of 40°C;

(4) Acid washing and desulfurization: After the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment. The treatment time is 1 hour, and the filtrate II and filter residue II are obtained after filtration , the filter residue II is used as Portland cement mixing material, and the XRD pattern, SEM image and physical map of the filter residue II are shown in Figure 2, Figure 3 and Figure 4;

(5) Photoreduction: combine filtrate Ⅰ and filtrate Ⅱ and carry out photoreduction, use a 500W xenon lamp light source to irradiate for 4 hours, the distance between the light source and the mixed solution is fixed at 5cm, and the light intensity is 1000W/m ² (0.1J/cm ² ), the filtrate III and filter residue III were obtained after filtration, the filter residue III was washed to neutrality, and dried at 60°C for 12 hours to obtain (Fe,Mn)C ₂ O ₄ composite material, (Fe,Mn)C ₂ O ₄ The composite material is used to treat Cr(VI) polluted wastewater, and the filtrate III is returned to the manganese sulfate production system. The flow chart of the above process is shown in Figure 1.

The leaching rate and desulfurization rate of iron in manganese slag after different steps of treatment were detected, and the results were 94.5% and 96.19% respectively.

The main components in the filter residue II were analyzed, as shown in Table 1.

Table 1 Main chemical components of filter residue Ⅱ

It can be seen from Table 1 that the main chemical components of filter residue II, SO ₃ , MgO and chloride ion content, all meet the GB 175-2007 "General Portland Cement" standard, indicating that when filter residue II is used as a Portland cement mixing material, the production The high-quality Portland cement can meet the standard of GB 175-2007 "General Portland Cement", which effectively improves the stability of cement and reduces the cost of cement production.

Use the (Fe, Mn)C ₂ O ₄ composite material obtained in step (5) to carry out the treatment of Cr(VI) polluted wastewater. The treatment process is: add 0.05mg (Fe, Mn)C ₂ O ₄ composite material to 50mL 40mg /L of hexavalent chromium solution, and use 0.1M sodium hydroxide solution and 0.1M hydrochloric acid solution to adjust the pH of the initial solution to 2-9 as required. The results show that the adsorption capacity is 122.7mg g ^-1 . When pH=3, Cr(VI) was completely removed within 20min, and it had good removal ability in a wide pH range of 2-9.

Example 2

A method for resource utilization of manganese slag produced in the production process of manganese sulfate, comprising the following steps:

(1) Acid leaching extraction: After heating the H ₂ C ₂ O ₄ solution with a concentration of 2mol/L, add the manganese slag produced in the manganese sulfate production process, and the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to the manganese slag is 12:1, react at a stirring speed of 200rpm and a temperature of 80°C for 0.5h, and obtain filtrate I and filter residue I after filtration and washing;

(2) Mechanical activation: add filter residue I with a volume ratio of 8:1 and ball milling medium zirconia into a mechanical activation solid-phase reactor for mechanical activation pretreatment, and treat for 2 hours at a speed of 350 rpm and a temperature of 45 °C , to obtain the pretreated filter residue I;

(3) Oxidative desulfurization: add the pretreated filter residue I into _{the H2O2} solution with a volume fraction of 10% for oxidative desulfurization treatment, and add _H2SO4 solution with a concentration of _0.1mol /L to maintain the acidic environment. React for 2 hours at a stirring speed of 200 rpm and a temperature of 35°C;

(4) Acid washing and desulfurization: After the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment. The treatment time is 0.5h, and the filtrate II and filter residue are obtained after filtration Ⅱ, filter residue Ⅱ is used as Portland cement mixing material;

(5) Photoreduction: combine filtrate Ⅰ and filtrate Ⅱ and carry out photoreduction, use a 500W xenon lamp light source to irradiate for 3 hours, the distance between the light source and the mixed solution is fixed at 5cm, and the light intensity is 1000W/m ² (0.1J/cm ² ), the filtrate III and filter residue III were obtained after filtration, the filter residue III was washed to neutrality, and dried at 60°C for 12 hours to obtain (Fe,Mn)C ₂ O ₄ composite material, (Fe,Mn)C ₂ O ₄ The composite material is used to treat Cr(VI) polluted wastewater, and the filtrate III is returned to the manganese sulfate production system. The flow chart of the above process is shown in Figure 1.

The leaching rate and desulfurization rate of iron in manganese slag after different steps of treatment were detected, and the results were 85.5% and 83.2% respectively.

The main components in the filter residue II were analyzed, as shown in Table 2.

Table 2 Main chemical components of filter residue Ⅱ

Example 3

A method for resource utilization of manganese slag produced in the production process of manganese sulfate, comprising the following steps:

(1) Acid leaching extraction: After heating the H ₂ C ₂ O ₄ solution with a concentration of 1mol/L, add the manganese slag produced in the manganese sulfate production process, and the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to the manganese slag is 8:1, reacted for 3 hours at a stirring speed of 600rpm and a temperature of 70°C, obtained filtrate I and filter residue I after filtration and washing;

(2) Mechanical activation: Add filter residue I with a volume ratio of 12:1 and ball milling medium zirconia into a mechanical activation solid-phase reactor for mechanical activation pretreatment, and treat for 1.5 hours at a speed of 500 rpm and a temperature of 60 Obtain pretreated filter residue I;

(3) Oxidative desulfurization: Add the pretreated filter residue I into a _H2O2 solution with a volume fraction of 15% for oxidative desulfurization treatment, and add _{a H2SO4} solution with a concentration of _0.1mol /L to maintain an acidic environment. React for 0.5h at a stirring speed of 600rpm and a temperature of 45°C;

(4) Acid washing and desulfurization: After the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment. The treatment time is 1.5 hours, and the filtrate II and filter residue are obtained after filtration Ⅱ, filter residue Ⅱ is used as cement raw meal or Portland cement mixed material;

(5) Photoreduction: combine filtrate Ⅰ and filtrate Ⅱ and carry out photoreduction, use a 500W xenon lamp light source to irradiate for 3.5h, the distance between the light source and the mixed solution is fixed at 5cm, and the light intensity is 1000W/m ² (0.1J/ cm ² ), the filtrate III and filter residue III were obtained after filtration, the filter residue III was washed to neutrality, and dried at 60°C for 12 hours to obtain (Fe,Mn)C ₂ O ₄ composite material, (Fe,Mn)C ₂ O ₄ The composite material is used to treat Cr(VI) polluted wastewater, and the filtrate III is returned to the manganese sulfate production system. The flow chart of the above process is shown in Figure 1.

The leaching rate and desulfurization rate of iron in manganese slag after different steps of treatment were detected, and the results were 80.2% and 87.4% respectively.

The main components in the filter residue II were analyzed, as shown in Table 3.

Table 3 Main chemical components of filter residue Ⅱ

Example 4

A method for resource utilization of manganese slag produced in the production process of manganese sulfate, comprising the following steps:

(1) Acid leaching extraction: After heating the H ₂ C ₂ O ₄ solution with a concentration of 3mol/L, add the manganese slag produced in the manganese sulfate production process, and the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to the manganese slag is 15:1, reacted for 3 hours at a stirring speed of 500rpm and a temperature of 70°C, and obtained filtrate I and filter residue I after filtration and washing;

(2) Mechanical activation: add filter residue I and ball milling medium zirconia with a volume ratio of 8:1 to a mechanical activation solid-phase reactor for mechanical activation pretreatment, and process 0.5 at a speed of 400 rpm and a temperature of 60 °C. h, to obtain the pretreated filter residue I;

(3) Oxidative desulfurization: Add the pretreated filter residue I into _{the H2O2} solution with a volume fraction of 20% for oxidative desulfurization treatment, and add _H2SO4 solution with a concentration of _0.1mol /L to maintain the acidic environment. React for 2 hours at a stirring speed of 600 rpm and a temperature of 30°C;

(4) Pickling and desulfurization: After the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment. The treatment time is 0.5h, and the filtrate II and filter residue are obtained after filtration Ⅱ, filter residue Ⅱ is used as cement raw meal or Portland cement mixed material;

(5) Photoreduction: combine filtrate Ⅰ and filtrate Ⅱ and carry out photoreduction, use a 500W xenon lamp light source to irradiate for 3.5h, the distance between the light source and the mixed solution is fixed at 5cm, and the light intensity is 1000W/m ² (0.1J/ cm ² ), the filtrate III and filter residue III were obtained after filtration, the filter residue III was washed to neutrality, and dried at 60°C for 12 hours to obtain (Fe,Mn)C ₂ O ₄ composite material, (Fe,Mn)C ₂ O ₄ The composite material is used to treat Cr(VI) polluted wastewater, and the filtrate III is returned to the manganese sulfate production system. The flow chart of the above process is shown in Figure 1.

The leaching rate and desulfurization rate of iron in manganese slag after different steps of treatment were detected, and the results were 90.7% and 91.3% respectively.

The main components in the filter residue II were analyzed, as shown in Table 4.

Table 4 Main chemical composition of filter residue Ⅱ

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (9)

1. a method for the resource utilization of manganese slag produced in the manganese sulfate production process, is characterized in that, comprises the following steps: (1) Acid leaching extraction: After heating the H ₂ C ₂ O ₄ solution, add manganese slag produced in the production process of manganese sulfate, stir evenly, and obtain filtrate I and filter residue I after filtering and washing; (2) Mechanical activation: add filter residue I and ball milling medium zirconia into a mechanically activated solid-phase reactor for mechanical activation pretreatment to obtain pretreated filter residue I; the mechanical activation is at a speed of 350-500 rpm, Treat at a temperature of 45-60°C for 0.5-2 hours; (3) Oxidative desulfurization: add the pretreated filter residue I to the H ₂ O ₂ solution for oxidative desulfurization, and add H ₂ SO ₄ solution to maintain the acidic environment; (4) Acid washing and desulfurization: After the oxidation desulfurization treatment is completed, add H ₂ C ₂ O ₄ solution to the solution in step (3) for acid washing and desulfurization treatment, and obtain filtrate II and filter residue II after filtration; (5) Illumination reduction: combine the filtrate I and filtrate II and then carry out light reduction, and obtain filtrate III and filter residue III after filtration, wash the filter residue III until neutral, and obtain (Fe,Mn)C ₂ O ₄ compound after drying material, and the filtrate III is returned to the manganese sulfate production system. 2. The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1, characterized in that, in step (1), the acid leaching extraction is carried out at a stirring speed of 200-600 rpm and a temperature of React at 70-90°C for 0.5-3 h. 3. The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1, characterized in that, in step (1), the liquid-solid ratio of the H ₂ C ₂ O ₄ solution to manganese slag 8-15:1. 4. the method for resource utilization of manganese slag produced in the manganese sulfate production process according to claim 1, is characterized in that, in step (2), the volume ratio of described filter residue I and zirconium dioxide is 8-12: 1. 5. The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1, characterized in that, in step (3), the oxidative desulfurization is carried out at a stirring speed of 200-600 rpm and a temperature of React at 30-50°C for 0.5-2 h. 6 . The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1 , characterized in that, in step (4), the time for acid washing and desulfurization is 0.5-2 h. 7 . The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1 , characterized in that, in step (5), the light reduction time is 3-4 h. 8. The method for resource utilization of manganese slag produced in the production process of manganese sulfate according to claim 1, characterized in that in step (4), the filter residue II is used as cement raw meal or Portland cement mixed material . 9. the method for the resource utilization of the manganese slag produced in the manganese sulfate production process according to claim 1, is characterized in that, described (Fe, Mn)C ₂ O ₄ composite material is used for processing Cr (VI) polluted waste water .

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