Application of electrolytic manganese residues in promotion of reclamation of lead-zinc ore tailings and method for promoting reclamation of lead-zinc ore tailings through electrolytic manganese residues

Abstract

The invention provides application of electrolytic manganese residues in promotion of reclamation of lead-zinc ore tailings and a method for promoting reclamation of lead-zinc ore tailings by using the electrolytic manganese residues, and belongs to the technical field of ecological restoration. The electrolytic manganese residues are used as the lead-zinc ore tailings modifier, the physical property and the chemical property of the lead-zinc ore tailings can be improved, and therefore the growth condition of plants in the lead-zinc ore tailings is improved. Specifically, on one hand, the electrolytic manganese residues are added into the lead-zinc ore tailings, the particle structure of the lead-zinc ore tailings can be effectively improved, formation of tailings microaggregates is promoted, and therefore the physical properties of the lead-zinc ore tailings are improved. On the other hand, the electrolytic manganese residues can supplement available nitrogen and ammoniacal nitrogen, and the situation that the lead-zinc ore tailings are poor in nutrient is improved. According to the method, the electrolytic manganese residues are used for promoting reclamation of the lead-zinc ore tailings, and the growth condition of plants can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological restoration, and specifically relates to the application of electrolytic manganese residue in promoting the reclamation of lead-zinc mine tailings and a method for promoting the reclamation of lead-zinc mine tailings with electrolytic manganese residue. Background Art

[0002] Lead-zinc mine tailings are solid industrial wastes from the lead-zinc mining industry. The long-term storage of lead-zinc mine tailings not only occupies a large amount of land resources, but also, due to their loose structure, is easily washed away by precipitation, and may even cause the risk of tailings pond dam break. In addition, the toxic and harmful substances in lead-zinc mine tailings will migrate to the surrounding water bodies and soil through surface runoff, leaching, seepage, etc., posing a serious threat to the ecosystem and human health.

[0003] Currently, due to the limitations of the cost, technology, efficiency, and market demand of the secondary utilization technology of lead-zinc mine tailings, ecological restoration technology is still the mainstream method for disposing of lead-zinc mine tailings. Ecological restoration is considered a key element in reconstructing ecological balance and reversing environmental degradation, and vegetation plays an irreplaceable and important role in this process. However, due to the following defects of lead-zinc mine tailings: 1. Poor nutrients; 2. Poor physical properties. Compared with ordinary heavy metal-polluted soils, they have a poor particle mechanical composition, a very poor aggregate structure, and a lack of clay minerals that make up clay particles. These defects result in the difficulty of most plants growing in lead-zinc mine tailings. Therefore, lead-zinc mine tailings ponds are usually regarded as micro deserts that hinder the colonization of natural biological communities.

[0004] In response to the above problems, currently, the vegetation restoration method of adding soil is mostly adopted, including soil covering and soil replacement, to provide a relatively suitable substrate for vegetation growth. However, these physical treatment methods require a huge amount of soil, have low restoration efficiency and high investment, and are only applicable to small-scale tailings ponds. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide the application of electrolytic manganese residue in promoting the reclamation of lead-zinc mine tailings and a method for promoting the reclamation of lead-zinc mine tailings with electrolytic manganese residue. The present invention uses electrolytic manganese residue as a lead-zinc mine tailings modifier, which can adjust the physical and chemical properties of the lead-zinc mine tailings substrate and improve the plant colonization rate.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides the application of electrolytic manganese residue in promoting the reclamation of lead-zinc mine tailings.

[0008] Preferably, by mass percentage, the components of the electrolytic manganese residue include: 25-35% of silicon dioxide; 12-18% of calcium oxide; 5-10% of magnesium oxide; 3-8% of aluminum oxide; 2-5% of iron oxide; 17-25% of sulfate; 1-5% of manganese carbonate; 7.7-8.5% of total nitrogen; among which, the sulfate includes 10-13% of calcium sulfate, 6-8% of ammonium sulfate, and 1-4% of manganese sulfate.

[0009] Preferably, the lead-zinc ore tailings are carbonate-type lead-zinc ore tailings;

[0010] The pH value of the lead-zinc ore tailings is 6.5-8.5.

[0011] Preferably, by mass percentage of the lead-zinc ore tailings, the main metal elements of the lead-zinc ore tailings include: 2-10% of iron, 3-8% of aluminum, 3.6-7.2% of magnesium, 2-8% of calcium, 0.5-2.5% of lead, and 0.8-3.0% of zinc.

[0012] Preferably, the particle size of the lead-zinc ore tailings is 0.05-2 mm.

[0013] The present invention provides a method for promoting the reclamation of lead-zinc ore tailings by electrolytic manganese residue, comprising the following steps:

[0014] Mix the electrolytic manganese residue with the lead-zinc ore tailings, add water to the obtained mixture, and carry out equilibration and stabilization to obtain a planting substrate;

[0015] Plant plants in the planting substrate.

[0016] Preferably, the addition amount of the electrolytic manganese residue in the lead-zinc ore tailings is 0-2 wt%, and not 0.

[0017] Preferably, the addition amount of the electrolytic manganese residue in the lead-zinc ore tailings is 1 wt%.

[0018] Preferably, the equilibration and stabilization time is 15-30 days.

[0019] Preferably, during the equilibration and stabilization process, the moisture content of the mixture of the electrolytic manganese residue and the lead-zinc ore tailings is maintained at 10-20%.

[0020] The present invention provides an application of electrolytic manganese residue in promoting the reclamation of lead-zinc ore tailings. Electrolytic manganese residue (EMR) is an industrial solid waste generated during the process of smelting manganese metal from manganese ore. Electrolytic manganese residue is generally stored in an open-air environment, and its harmful components mainly exist in the forms of ammonium nitrogen and soluble manganese, posing a potential threat to the ecosystem and human health. The present invention uses electrolytic manganese residue as a modifier for lead-zinc ore tailings, which can improve the physical and chemical properties of lead-zinc ore tailings, thereby improving the plant growth conditions in lead-zinc tailings. Specifically, on the one hand, by adding electrolytic manganese residue to lead-zinc ore tailings, the present invention can effectively improve the particle structure of lead-zinc ore tailings and promote the formation of micro-aggregates of lead-zinc ore tailings, thereby improving the physical properties of lead-zinc ore tailings. On the other hand, electrolytic manganese residue can supplement available nitrogen and ammonium nitrogen and improve the nutrient-poor situation of lead-zinc ore tailings. Using electrolytic manganese residue to promote the reclamation of lead-zinc ore tailings in the present invention can significantly improve the growth conditions of plants. The results of the examples show that after adding 1 wt% of electrolytic manganese residue to lead-zinc ore tailings and planting Sudan grass, after three months of reclamation, the vegetation coverage rate in the area reaches 63.7%, and the biomass of Sudan grass reaches 196 g / m 2 . Description of the Drawings

[0021] Figure 1 Effect of adding different proportions of electrolytic manganese residue on the growth of ryegrass;

[0022] Figure 2 Growth status of Sudan grass under different reclamation times with the addition of electrolytic manganese residue;

[0023] Figure 3 Particle size proportion and aggregate distribution of lead-zinc ore tailings after three months of reclamation. Specific Embodiments

[0024] The present invention provides an application of electrolytic manganese residue in promoting the reclamation of lead-zinc ore tailings.

[0025] In the present invention, the electrolytic manganese residue is an industrial solid waste generated by smelting manganese metal from manganese ore. In the present invention, the particle size of the electrolytic manganese residue is preferably ≤2 mm. In the present invention, in terms of mass percentage, the components of the electrolytic manganese residue preferably include: silicon dioxide 25-35%; calcium oxide 12-18%; magnesium oxide 5-10%; aluminum oxide 3-8%; iron oxide 2-5%; sulfate 17-25%; manganese carbonate 1-5%; total nitrogen 7.7-8.5%; the sulfate includes 10-13% of calcium sulfate, 6-8% of ammonium sulfate, and 1-4% of manganese sulfate.

[0026] In the present invention, the lead-zinc ore tailings are preferably carbonate-type lead-zinc ore tailings; the pH value of the lead-zinc ore tailings is preferably 6.5 to 8.5, more preferably 7 to 8. In the present invention, in terms of the mass percentage content of the lead-zinc ore tailings, the main metal elements of the lead-zinc ore tailings preferably include: iron 2 to 10%, aluminum 3 to 8%, magnesium 3.6 to 7.2%, calcium 2 to 8%, lead 0.5 to 2.5%, and zinc 0.8 to 3.0%.

[0027] In the present invention, the particle size of the lead-zinc ore tailings is 0.05 to 2 mm. As a specific embodiment of the present invention, the particle size distribution of the lead-zinc ore tailings is preferably: the mass content of the lead-zinc ore tailings with a particle size of 0.5 to 2 mm is 22.9%, the mass content of the lead-zinc ore tailings with a particle size of 0.25 to 0.5 mm is 56.3%, and the mass content of the lead-zinc ore tailings with a particle size of 0.05 to 0.25 mm is 20.8%.

[0028] The present invention provides a method for promoting the reclamation of lead-zinc ore tailings with electrolytic manganese slag, comprising the following steps:

[0029] Mix the electrolytic manganese slag with the lead-zinc ore tailings, add water to the obtained mixture, and perform equilibration and stabilization to obtain a planting substrate;

[0030] Plant plants in the planting substrate.

[0031] In the present invention, the electrolytic manganese slag is mixed with the lead-zinc ore tailings, water is added to the obtained mixture, and equilibration and stabilization are performed to obtain a planting substrate. In the present invention, the addition amount of the electrolytic manganese slag in the lead-zinc ore tailings is preferably 0 to 2 wt%, and not 0, specifically it can be 0.5 wt%, 1 wt%, 1.5 wt% or 2 wt%, preferably 1 wt%. In the present invention, since the electrolytic manganese slag contains heavy metals and a large amount of soluble salts, the addition amount cannot be too high. If the content of the electrolytic manganese slag is further increased, it will cause a problem of secondary pollution to the lead-zinc ore tailings.

[0032] The present invention has no special requirements for the mixing method, and a mixing method well-known to those skilled in the art can be used, such as stirring and mixing specifically.

[0033] In the present invention, the mass of the water is preferably 10 to 20% of the mass of the mixture, specifically preferably 10%, 12%, 15%, 18% or 20%.

[0034] The present invention is preferably carried out for equilibrium stabilization under static conditions. The temperature for the equilibrium stabilization is preferably 20 - 30°C, more preferably 25°C, and the time is preferably 15 - 30 days, more preferably 20 - 25 days. In the present invention, during the process of equilibrium stabilization, the present invention preferably supplements water to the mixture, so that the moisture content of the mixture of electrolytic manganese slag and lead-zinc ore tailings is maintained at 10 - 20%, specifically it can be 10%, 12%, 15%, 18% or 20%.

[0035] After obtaining the planting substrate, the present invention plants plants in the planting substrate. In the present invention, the plants are preferably one or several of ryegrass, sudangrass, miscanthus and kudzu. The present invention has no special requirements for the planting method, and the planting methods well-known to those skilled in the art can be adopted.

[0036] The present invention provides a lead-zinc ore tailings reclamation improver, the components of which include electrolytic manganese slag. In the present invention, the lead-zinc ore tailings reclamation improver preferably further includes other auxiliary materials or other improving active components.

[0037] The following examples are used to illustrate in detail the application of electrolytic manganese slag provided by the present invention in promoting the reclamation of lead-zinc ore tailings and a method for promoting the reclamation of lead-zinc ore tailings by electrolytic manganese slag, but they should not be construed as limiting the protection scope of the present invention.

[0038] The lead-zinc ore tailings used in the following examples were taken from a lead-zinc ore tailings reservoir in Yangshuo County, Guilin City. Before the test, the plant debris and residues in the tailings sample were removed, and after natural drying indoors, it was passed through a standard sieve with a pore size of 2 mm for homogenization treatment. The main metal elements of the lead-zinc ore tailings include: iron 6.8%, aluminum 7.7%, magnesium 3.6%, calcium 7.6%, lead 0.6%, zinc 1.1%, and the particle size distribution is: 0.5 - 2 mm accounts for 22.9%, 0.25 - 0.5 mm accounts for 56.3%, 0.05 - 0.25 mm accounts for 20.8%.

[0039] The electrolytic manganese slag used in the following examples was taken from an electrolytic manganese slag yard in Pingle County, Guilin City. The electrolytic manganese slag was ground and passed through a standard sieve with a pore size of 2 mm and homogenized before use. The specific components of the electrolytic manganese slag include: silicon dioxide 32%; calcium oxide 14%; magnesium oxide 5.6%; aluminum oxide 4.1%; iron oxide 2.4%; calcium sulfate 11.2%; ammonium sulfate 7.1%; manganese sulfate 3.8%; manganese carbonate 2.9%; total nitrogen 7.8%.

[0040] Example 1 Influence of adding electrolytic manganese slag on the growth of ryegrass

[0041] The experiment was designed with a control (0) without adding electrolytic manganese slag and 3 improved treatments. Among them, 0 was the lead-zinc ore tailings without adding electrolytic manganese slag, and the treatment groups were adding electrolytic manganese slag (w / w) to the tailings at 0.5%, 1%, and 2% respectively. Each treatment was set with 3 replicates. The experiment used 2L plastic buckets as containers, and 3kg of the mixed matrix of tailings and electrolytic manganese slag was loaded into the plastic buckets. 500mL of water was added and balanced for 30 days to obtain the planting matrix. During the cultivation period, the moisture content of the matrix was maintained at 10-20%.

[0042] The effects of adding electrolytic manganese slag on the basic chemical properties of lead-zinc ore tailings are shown in Table 1. Among them, a Leici pHS-3C pH meter (1:2.5 w / v) was used to measure the pH of the samples; a Leici DDS-307 conductivity meter (1:5 w / v) was used to measure the soil conductivity; the ammonium nitrogen content was determined by the Nessler reagent colorimetric method, and the nitrate nitrogen content was determined by the ultraviolet spectrophotometric method. The cation exchange capacity of the samples was determined by the cobalt hexammine trichloride-spectrophotometric method. The exchangeable calcium content was determined by an inductively coupled plasma spectrometer. The available manganese content was determined by the diethylenetriaminepentaacetic acid extraction-inductively coupled plasma emission spectrometry method.

[0043] Table 1 Effects of adding electrolytic manganese slag on the basic chemical properties of tailings

[0044] Parameter 0 0.5％ 1％ 2％ pH 8.04±0.03 7.88±0.03 7.38±0.02 7.01±0.02 Soil electrical conductivity EC (μS / cm) 610±5.20 750±16.1 1380±14.8 1750±19.3 <![CDATA[Cation exchange capacity CEC (cmol + / kg)]]> 2.17±0.02 2.00±0.09 2.73±0.06 4.12±0.23 <![CDATA[Ammonium nitrogen (mg·kg -1 )]]> 11.3±0.32 15.1±0.81 41.8±0.74 58.4±2.66 <![CDATA[Nitrate nitrogen (mg·kg -1 )]]> 4.25±0.26 4.23±0.10 8.68±2.40 9.63±0.87 <![CDATA[Exchangeable calcium (mg·kg -1 )]]> 410±14.1 741±21.8 1050±50.4 1560±21.5 <![CDATA[Available Mn (mg·kg -1 )]]> 18.2±2.58 55.4±4.57 91.9±2.12 136±5.52

[0045] As can be seen from Table 1, after adding electrolytic manganese slag, the pH value of the lead-zinc ore tailings decreased, the EC value increased, and the exchangeable calcium and available manganese contents increased.

[0046] Using the lead-zinc ore tailings treated with electrolytic manganese slag in different groups as the substrate to plant ryegrass, the germination rate of ryegrass was measured on the 7th day, and the fresh weight and plant height of ryegrass in each group were measured at the harvest on the 30th day, and the physical pictures were taken. The results are as Figure 1 shown. It can be seen from Figure 1 that as the addition amount of electrolytic manganese slag increased, its effect on the germination rate of ryegrass showed a trend of first promoting and then inhibiting. Among them, adding 0.5% and 1% of electrolytic manganese slag increased the germination rate of ryegrass by 18.1% and 15.8% respectively. Adding 0.5% and 1% of electrolytic manganese slag increased the fresh weight of ryegrass by 10.3% and 13.8% respectively. Adding 0.5% and 1% of electrolytic manganese slag would increase the plant height of ryegrass.

[0047] Example 2

[0048] Select a 3m×5m bare plot in a lead-zinc ore tailings reservoir in Guilin, Guangxi for restoration. Add 1wt% of electrolytic manganese slag to the tailings (calculated by points with a length of 10cm, a width of 10cm, and a depth of 20cm) and plant Sudan grass. The restoration effects at different reclamation times are as Figure 2As shown, it can be seen that three months after reclamation, the vegetation coverage rate in the area reached 63.7%, and the biomass of Sudan grass reached 196 g / m 2 (calculated by fresh weight).

[0049] The particle size proportion and aggregate distribution of lead-zinc mine tailings three months after reclamation are as Figure 3 shown. It can be seen that three months after reclamation, the proportion of lead-zinc mine tailings with a particle size of 1-100 μm decreased significantly, the proportion of those with a particle size of 100-1000 μm increased significantly, the aggregates in the range of 0.5-2 mm increased, and the aggregates in the range of 0.5-0.25 mm decreased.

[0050] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Application of electrolytic manganese slag in promoting the reclamation of lead-zinc mine tailings.

2. The use according to claim 1, characterized in that: The components of the electrolytic manganese slag include, by mass percentage, 25-35% silicon dioxide, 12-18% calcium oxide, 5-10% magnesium oxide, 3-8% aluminum oxide, 2-5% iron oxide, 17-25% sulfate, 1-5% manganese carbonate, and 7.7-8.5% total nitrogen; the sulfate includes 10-13% calcium sulfate, 6-8% ammonium sulfate, and 1-4% manganese sulfate.

3. The use according to claim 1, characterized in that: The lead-zinc ore tailings are carbonate rock type lead-zinc ore tailings; The pH value of the lead-zinc ore tailings is 6.5-8.

5.

4. The use according to claim 1 or 3, characterized in that: Calculated by mass percentage of the lead-zinc tailings, the main metal elements of the lead-zinc tailings include: 2-10% iron, 3-8% aluminum, 3.6-7.2% magnesium, 2-8% calcium, 0.5-2.5% lead, and 0.8-3.0% zinc.

5. The use according to claim 1, characterized in that: The particle size of the lead-zinc ore tailings is 0.05-2 mm.

6. A method for promoting lead-zinc mine tailings reclamation by electrolytic manganese slag, characterized in that: The following steps are involved: The electrolytic manganese slag is mixed with the lead-zinc ore tailings, and water is added to the obtained mixture to balance and stabilize it to obtain a planting medium; Plants are planted in the planting medium.

7. The method according to claim 6, characterized in that The amount of the electrolytic manganese slag added to the lead-zinc ore tailings is 0-2wt%, and is not 0.

8. The method according to claim 7, characterized in that The amount of the electrolytic manganese slag added to the lead-zinc ore tailings is 1wt%.

9. The method according to claim 6 or 7, characterized in that: The equilibrium stability period is 15 to 30 days.

10. The method according to claim 6 or 7, characterized in that: During the process of balancing and stabilizing, the water content of the mixture of electrolytic manganese slag and lead-zinc ore tailings is maintained at 10-20%.

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