A quick ecological restoration system and method for legacy smelting slag

Abstract

The application discloses a kind of quick ecological restoration system and method of left smelting waste residue, the method includes site leveling, gold hair moss planting, forms gold hair moss survival site, grass seed mixed sowing, shrub planting, soil and biomass increment.The application is under the condition of no substrate Ecological restoration of historical left sulfur smelting waste residue, establish stable "moss-grass-shrub-tree" vegetation layer, with the effect of preventing loss of waste residue, blocking rainwater leaching, risk control acid waste residue continuous acidification.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ecological environment governance, and particularly relates to a rapid ecological restoration system and method for left-over smelting slag. BACKGROUND

[0002] In the process of regional economic development, a large amount of smelting slag left over by local smelting is left in the site within the range of important rivers or tributaries in the region, causing ecological damage problems such as land occupation, water acidification and landscape damage. How to realize the risk control and ecological restoration of the historical left-over sulfur smelting slag is a difficult problem restricting the construction of regional ecological civilization.

[0003] At present, the technology widely used in the field of ecological restoration of mines is a covering substrate layer and a vegetation layer, and it is believed that the bare surface has no vegetation growth conditions. For example, the prior art discloses an ecological restoration structure and method for rapidly greening the slope of Zhongshan terrain wind power field, which comprises a non-woven fabric strip filled with a cultivation substrate, a fixing net, a substrate soil layer and a greening layer composed of dormant moss after awakening and growing. Although this method can realize the rapid greening of the slope, it does not solve the problem of relying on the cultivation substrate to ensure the greening effect; and the prior art also discloses a vegetation restoration structure and method for abandoned limestone mine slope, which comprises a base surface, a slag stone layer, an organic matter water retention layer, a soil covering layer, a spray layer, a spray layer and a moss layer, which still largely relies on the setting of the substrate soil layer and the provision of organic matter to realize the restoration purpose.

[0004] In addition, the prior art also discloses a method for covering the bare rock slope with a moss ecological blanket, which uses a factory-assembled moss ecological blanket to realize rapid greening, but the installation is complex and the cost is high. The installation accessories such as fixing nails and caps have poor adaptability, and the greening effect relies on the ecological blanket, and does not use the site or slag to form a stable substrate layer to realize the rapid ecological restoration of the site.

[0005] Therefore, how to find and optimize the pioneer plants in the site range where ecological restoration needs to be implemented, realize the accumulation of soil on the surface layer of the accumulated slag in the site, further strengthen the thickness and surface biomass of the accumulated soil layer, and realize the rapid ecological restoration of the restoration site is worth studying. SUMMARY

[0006] In view of the above problems, the present application provides a rapid ecological restoration system and method for left-over smelting slag, which does not use substrate soil and does not add artificial nutrients, optimizes the moss plant Pogonatum japonicum which can realize the accumulation of soil on the surface layer of the slag, and is supplemented with mixed grass seeds and planted shrubs and trees. The method of "moss-grass-shrub-tree" combination realizes rapid ecological restoration.

[0007] The technical scheme of the present application is as follows:

[0008] A kind of quick ecological restoration system of legacy smelting waste residue, including base rock layer, original soil layer formed by rock weathering, legacy sulfur smelting acid waste residue, pioneer plant golden moss, moss crust and accumulated soil layer, mixed sowing grass species, pioneer acid-resistant plant birch and culture medium tree species cedar;

[0009] Original soil layer formed by rock weathering is located above base rock layer;Legacy sulfur smelting acid waste residue is located above original soil layer formed by rock weathering;

[0010] Pioneer plant golden moss is planted on legacy sulfur smelting acid waste residue before rainy season, and mixed sowing grass species is planted in accumulated soil on the surface of the resulting golden moss survival site legacy sulfur smelting acid waste residue;

[0011] Pioneer acid-resistant plant birch and culture medium tree species cedar are planted in accumulated soil on the surface of the resulting golden moss survival site legacy sulfur smelting acid waste residue;

[0012] The resulting birch and cedar trunk and plant are retained, branches are cut off within the scope of the restoration site, forming a natural culture medium, further promoting the adhesion of pioneer plant golden moss to the historical legacy sulfur smelting waste residue, obtaining moss crust and accumulated soil layer, increasing soil accumulation and biomass on the surface of the waste residue.

[0013] Further, the mixed sowing grass species is specifically two or more of money rush, stone pine, Chinese lalang, white clover, kikuyu grass, perennial ryegrass and alfalfa.

[0014] Further, the planting method of pioneer acid-resistant plant birch and culture medium tree species cedar is sowing seeds, germination in the same year, and survival rate is greater than or equal to 75%.

[0015] The present application also relates to a kind of quick ecological restoration method of legacy smelting waste residue, comprising the following steps:

[0016] S1, site leveling: the site leveling of the legacy smelting waste residue in the range needing ecological restoration is carried out, and the specific method is "high digging low filling", to form a certain slope;

[0017] S2, golden moss planting: golden moss is planted on the site obtained in step (1) before rainy season, and indoor culture is adopted for transplantation or field spore planting;

[0018] S3, form golden moss survival site: the golden moss survival site obtained in step (2), the water retention of golden moss accumulates water and floating dust in the surrounding environment, and obtains animal acidic metabolites as food for birds and mammals, and the decomposition of acidic waste residue in natural environment forms moss crust and soil, and the soil thickness accumulates to 2cm thick, and the moss crust rate can reach more than 70%;

[0019] S4, grass seed mixed sowing: planting two or more of the following species in the soil accumulated on the surface of the historical smelting slag in the habitat of the surviving Hypnum curvifolium obtained in step (3): Paspalum notatum, Lycopodium, Imperata cylindrica, Trifolium repens, Cynodon dactylon, Lolium multiflorum, and Medicago sativa, by sowing the seeds;

[0020] S5, arbor planting: planting two pioneer plants, birch and Japanese cedar, in the soil accumulated on the surface of the historical smelting slag in the habitat of the surviving Hypnum curvifolium obtained in step (3), by sowing the seeds, germination in the same year, and survival rate greater than or equal to 75%;

[0021] S6, soil and biomass increment: retaining the trunks and plants of the birch and Japanese cedar obtained in step (5), cutting the branches within the scope of the restoration site, forming a natural culture medium, further promoting the adhesion of Hypnum curvifolium to the historical sulfur smelting slag, and increasing soil accumulation and surface biomass of the slag.

[0022] Further, in S1, the historical smelting slag is excavated and backfilled using excavation machinery, the high and steep slope formed by long-term rainwater erosion is pushed, and the geological disaster hazard is eliminated; the excavated slag is piled up with a slope not steeper than 1:3.0, the excavated slag is backfilled in the low-lying areas of the site, the backfilled slag needs to be compacted with a compaction degree greater than 0.8; after the excavation and backfilling are completed, there should be no water accumulation in the site.

[0023] Further, in S1, the historical smelting slag is acid sulfur smelting slag, the accumulation time is more than 40 years, and the surface slag is exposed, the coarse particles account for more than 50% in the particle composition, and the others are mainly powdery cementation particles.

[0024] Further, in S2, the slag fine particles and Hypnum curvifolium are mixed and then sown on the restoration site, the mixing ratio is 15-20:1, and the sowing amount is 120-135 kg / hm 2 .

[0025] Further, in S3, the acid sulfur smelting slag surface attached with Hypnum curvifolium forms a moss crust and a soil layer, characterized by a moss survival rate of more than 50% and a thickness of not less than 2 cm.

[0026] Further, in S6, the branches are cut to a length of 5-20 cm and a width of 1-10 cm, and are placed in the natural environment to naturally rot into high-quality adhesion bodies of S2, wherein the birch trees achieve shrub coverage in the site through the fruits produced by the surviving plants; the Japanese cedar trees are reserved for economic forests according to regional planning, and are only planted around the restoration site for natural forests to ensure the biomass of Hypnum curvifolium.

[0027] Further, within 2 years, the "moss-grass-shrub-arbor" vegetation layer is realized, the Hypnum curvifolium survives, adheres, forms a crust, and forms a soil layer that meets the needs of vegetation restoration in the same year, and the "grass-shrub-arbor" survives and grows in the next year.

[0028] In step S1, the key parameter is the slope control without water accumulation and landslide. In step S2, the key parameter is the planting of P. stramineum, field survival transplanting or spore planting. In step S3, the key parameter is that the water retention of P. stramineum provides necessary conditions for the growth of plants and rapid vegetation restoration of the site, and the accumulation of original soil formed in the growth process of P. stramineum provides necessary conditions for subsequent rapid ecological restoration and the growth of other plants. In step S4, the water retention and soil formation conditions of P. stramineum under the condition of no substrate are used to increase the biomass (biodiversity). In step S5, the branches of shrubs are planted as culture medium to further promote the growth of P. stramineum, and after multiple cycles, the vegetation coverage requirement of ecological restoration can be achieved.

[0029] The core technology is to use P. stramineum to retain water and form soil (soil accumulation) on the surface of the historical residual slag to provide conditions for plant survival, and then increase the plant species and biomass to promote the growth of P. stramineum in the opposite direction, and further complete the ecological restoration necessary conditions of water retention and soil formation.

[0030] The technical difficulty is that in the process of ecological restoration, in order to make plants survive, it is necessary to take topsoil from outside. With the increasing demand for environmental protection, taking soil is not only a cost problem, but also a problem of new damage caused by the treatment of an old site. Therefore, one of the technical difficulties is soil formation. In engineering practice, P. stramineum can naturally survive on the surface of the historical residual smelting slag under natural conditions without substrate, and accumulate topsoil, and then other grasses can survive near P. stramineum.

[0031] Compared with the prior art, the beneficial effects of the present application are as follows:

[0032] 1. By screening of pioneer plants, the present application realizes water retention and soil accumulation, realizes restoration of vegetation layer, does not need artificial backfilling of cultivated soil, effectively solves the damage to regional topsoil and vegetation in the process of ecological restoration, and can also maximize the maintenance of natural restoration vegetation in the restoration site.

[0033] 2. The present application can quickly realize the vegetation restoration of the restoration site, the vegetation layer can intercept rainwater, and can also solve the loss problem caused by rainwater slag washing.

[0034] 3. The present application optimizes the vegetation layer and its lateral growth root system, and forms a barrier with the accumulated soil on the surface, which can also effectively alleviate the soaking of rainwater on the slag, reduce the leaching of acid slag and the amount of acid wastewater, and play a role in risk control of continuous acidification of acid slag. The present application artificially intervenes and strengthens the phenomenon found in nature to realize rapid ecological restoration. It has been proved by time in many projects in Zhaotong, Yunnan, and the technology is feasible and the effect is obvious. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 Figure 1 is a schematic diagram of the overall structure of the system of the embodiment of the present application;

[0036] 1 - substrate rock layer, 2 - original soil layer formed by rock weathering, 3 - historical sulfur smelting acid waste residue, 4 - pioneer plant Pogonatum japonicum, 5 - moss crust and accumulated soil layer, 6 - mixed grass species, 7 - pioneer plant Betula albo-sinensis, 8 - culture medium tree species Cryptomeria japonica. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. If no specific technology or condition is specified in the embodiments, the technology or condition described in the literature or according to the product manual is used. If no manufacturer of the reagent or instrument is specified, it is a conventional product that can be purchased. Example 1

[0038] As shown in Figure 1, the rapid ecological restoration system of the historical smelting waste residue of the present embodiment includes a substrate rock layer 1, an original soil layer 2 formed by rock weathering, a historical sulfur smelting acid waste residue 3, a pioneer plant Pogonatum japonicum 4, a moss crust and accumulated soil layer 5, a mixed grass species 6, a pioneer acid-resistant plant Betula albo-sinensis 7, and a culture medium tree species Cryptomeria japonica 8. Figure 1 The original soil layer 2 formed by rock weathering is located above the substrate rock layer 1; the historical sulfur smelting acid waste residue 3 is located above the original soil layer 2 formed by rock weathering.

[0039] The planting of the pioneer plant Pogonatum japonicum 4 on the historical sulfur smelting acid waste residue 3 is completed before the rainy season, and the mixed grass species 6 is mixed and planted in the accumulated soil on the surface of the historical sulfur smelting acid waste residue 3 in the resulting Pogonatum japonicum survival site.

[0040] The pioneer acid-resistant plant Betula albo-sinensis 7 and the culture medium tree species Cryptomeria japonica 8 are planted in the accumulated soil on the surface of the historical sulfur smelting acid waste residue 3 in the resulting Pogonatum japonicum survival site. The resulting Betula albo-sinensis and Cryptomeria japonica tree trunks and plants are retained, and the branches are cut within the scope of the restoration site to form a natural culture medium, further promote the adhesion of the pioneer plant Pogonatum japonicum 4 to the historical sulfur smelting acid waste residue, obtain a moss crust and accumulated soil layer 5, and increase soil accumulation and biomass on the surface of the waste residue.

[0041] Based on the above system, the rapid ecological restoration method of the historical smelting waste residue of the present embodiment includes the following steps:

[0042]

[0043] ​S1, site leveling: the historical sulfur smelting slag site is blocked and leveled, and the bare slag surface is leveled to 1:50 to ensure that there is no water accumulation in the site; the local steep slope is controlled to a slope of 1:3.5 to maintain the stability of the accumulated slope. The range of natural vegetation recovery is not leveled. The compaction degree of the backfill slag is not less than 0.8, which can be used.

[0044] S2, moss planting: according to the repair area and the meteorological environment conditions around the site, indoor culture is used for the moss. Before the rainy season, the stems are transplanted to the repair site after growing to 5-6 cm in length. The technical parameters for transplantation are that the moss coverage width is 30 cm, the interval is 60 cm, and the interval coverage is 60 cm.

[0045] S3, forming a moss survival site: the moss survival site is formed in the rainy season, and the moss survival rate is about 55%. After the autumn and winter seasons of the same year, moss crust and soil accumulation begin to form, and fine particles in the historical slag can also be used as a water retention layer, which can reach a thickness of 0-2.5 cm of moss crust and accumulated soil layer. The water retention of the moss can accumulate water and floating dust in the surrounding environment, and can also be used as food for birds and mammals to obtain animal acidic metabolites. In addition to the decomposition of acidic slag in the natural environment, moss crust and soil are formed, and the thickness of the soil accumulates to 2 cm thick, and the moss crust rate can reach 75%.

[0046] S4, grass seed mixed sowing: in the moss survival site, spring sowing the next year, planting four kinds of mixed sowing of money pampas, Chinese silvergrass, white clover, and perennial ryegrass, with a seed quality ratio of 1:1:1:1. The planting method is to scatter the grass seeds, and the sowing density is 150 kg / hm 2 .

[0047] S5, shrub planting: in the moss survival site, spring sowing the next year, planting birch and cedar, and dotting the tree species, with a technical parameter of 2m interval arrangement in a plum blossom shape, and germination in the same year. The observation data of the annual height growth of birch is 12-24 cm, and the survival rate can reach 90%; the observation data of the annual height growth of cedar is 15-30 cm, and the survival rate can reach 80%.

[0048] S6, soil and biomass increment: in the next autumn and winter season, the survival of mixed sowing grass and dotting shrubs further increases the soil accumulation, and the biomass of the slag surface further promotes the formation of the repair site community, and promotes each other. After the site risk control and ecological restoration, the site is optimized according to the nature of the site. In the embodiment, the fruits produced by the surviving birch trees realize the shrub coverage in the site, and the cedar trees are planted around the repair site in a natural forest way to form an ecological protection buffer zone with a width of 5m.

[0049] The embodiment solves the problems of acid waste residue loss prevention and acid wastewater reduction, and achieves the risk control target of 100% prevention of loss and erosion of historical acid waste residue in the site, and the ecological restoration target of 85% vegetation coverage. Example 2

[0050] The rapid ecological restoration method of the historical smelting waste residue in the embodiment includes the following steps:

[0051] S1, site leveling: the high and steep slope formed in the historical sulfur smelting waste residue site is repaired and shaped, and the technical requirements for the site leveling of the exposed waste residue surface are that the waste residue accumulation surface is controlled to have a slope of 1:10, which is beneficial to the diversion of rainwater in the site while taking into account the landscape restoration effect of the site. The site leveling is not performed in the range of natural vegetation restoration, and the natural stream in the waste residue accumulation site is maintained to realize the water source required for ecological restoration in the site.

[0052] S2, Pogonatum japonicum planting: the water source in the site is sufficient, and Pogonatum japonicum is cultivated by wild spore. During the rainy season, Pogonatum japonicum is reseeded according to the survival amount. The spore cultivation is performed by mixing and spreading the waste residue fine particles and Pogonatum japonicum to the restoration site, the mixing ratio is 15:1, and the spreading amount is 120 kg / hm 2 .

[0053] S3, Pogonatum japonicum survival site formation: the Pogonatum japonicum survival site is formed in the rainy season, and the survival rate of Pogonatum japonicum is about 65%. After the autumn and winter seasons of the same year, moss crust and soil accumulation begin to form, and at the same time, the fine particles in the historical waste residue can also be used as a water retaining layer, and the moss crust and accumulated soil layer can reach a thickness of 2.5 cm.

[0054] S4, grass seed mixed sowing: in the Pogonatum japonicum survival site, spring sowing is performed the next year, and three kinds of mixed sowing of Alocasia cucullata, Imperata cylindrica, and Medicago sativa are planted, the seed weight ratio is 1:1:1, and the planting method is to spread the grass seeds, and the sowing density is 130 kg / hm 2 .

[0055] S5, arbor planting: in the Pogonatum japonicum survival site, spring sowing is performed the next year, and Betula platyphylla and Cryptomeria japonica are planted, the tree species are point-sown, the technical parameters are 2m spacing in a plum blossom shape, and germination is achieved in the same year. The observation data of the annual height growth of Betula platyphylla is 8-12 cm, and the survival rate can reach 85%; the observation data of the annual height growth of Cryptomeria japonica is 10-25 cm, and the survival rate can reach 75%.

[0056] S6, soil and biomass increment: in the following autumn and winter season, the survival of mixed grass and sowing shrubs, after withering and leaf fall, further increase the soil accumulation, and the biomass on the surface of the waste residue can further promote the formation of the community of the remediation site, and promote each other. After 2 years, when the length of the main stem of the shrub is greater than 60 cm, the branches are artificially cut off as natural culture medium, the length of the cut branches is 5-25 cm, and the width is 1-10 cm, which is placed in the natural environment and naturally rots into the attachment of the hair moss. After the risk control and ecological remediation of the site, the site is optimized according to the nature of the site. In this embodiment, the birch tree realizes the coverage of shrubs in the site through the fruits produced by the surviving plants, and the cedar tree is reserved as an economic forest.

[0057] The embodiment solves the problems of loss prevention of acid waste residue and reduction of acid waste water, achieves the risk control target of 95% of the loss prevention rate and the erosion prevention rate of the historical acid waste residue left in the site, and the ecological remediation target of 90% of the vegetation coverage, and further increases about 20 mu of green land and the regional carbon sink. Embodiment 3

[0058] The rapid ecological remediation method of the left smelting waste residue in the embodiment comprises the following steps:

[0059] S1, site leveling: the high and steep slope formed in the historical sulfur smelting waste residue site is repaired and shaped, and the specific method is water impact shaping, punching in the waste residue, and injecting water after the hole is formed. Under the action of water splitting, the heap forms a site with a slope of 1:20-1:50, and the site is not waterlogged and has a certain landscape.

[0060] S2, hair moss planting: the site has sufficient water source, and the hair moss is cultivated by wild spores. During the rainy season, the hair moss is reseeded according to the survival amount. The spore cultivation adopts the method of mixing and spreading the waste residue fine particles and the hair moss to the remediation site, the mixing ratio is 20:1, and the spreading amount is 135 kg / hm 2 .

[0061] S3, forming a hair moss survival site: the hair moss survival site is formed in the rainy season, the survival rate of the hair moss is about 70%, and the thickness of the moss skin and accumulated soil layer can reach 3.5 cm.

[0062] S4, grass seed mixed sowing: in the hair moss survival site, the four kinds of mixed sowing of lycopodium, dog tooth grass, perennial ryegrass and alfalfa are sowed in the following spring, the seed weight ratio is 1:1:1:1, and the planting method is sowing grass seeds, and the sowing density is 140 kg / hm 2 .

[0063] S5, planting: in the next spring, plant birch and cypress in the site where the moss has survived, and arrange the trees in a plum blossom shape with a 2m interval, and the trees will germinate in the same year. The observed data of the annual height growth of birch is 8-12cm, and the survival rate can reach 85%; the observed data of the annual height growth of cypress is 10-25cm, and the survival rate can reach 75%.

[0064] S6, soil and biomass increment: in the next autumn and winter, the survived mixed grass and the broadcast shrubs further increase the soil accumulation after withering and leaf falling. After the length of the main stem of the shrubs reaches 40cm, the branches are manually cut off as natural culture medium, the length of the cut branches is 10-15cm, the width is 2-4cm, and the branches are placed in the natural environment to naturally rot and become the attachment of the moss. After the risk control and ecological restoration of the site, the site is optimized according to the nature of the site. In this embodiment, the birch trees realize the coverage of the shrubs in the site through the fruits produced by the survived plants, and the cypress trees are reserved as economic forests.

[0065] This embodiment solves the problems of loss prevention of acid slag and reduction of acid wastewater, completes the risk control target of 100% loss prevention rate and erosion prevention rate of the historical acid slag left in the site and the ecological restoration target of 95% vegetation coverage, and further increases about 40 mu of green land and the regional carbon sink. Embodiment 4

[0066] The rapid ecological restoration method of the left smelting slag in this embodiment includes the following steps:

[0067] S1 and S2 are the same as in embodiment 1.

[0068] S3, forming a site where the moss has survived: a site where the moss has survived is formed in the rainy season, the survival rate of the moss is about 75%, and the thickness of the moss skin and the accumulated soil layer can reach 4.0cm.

[0069] S4, mixed grass planting: in the next spring, plant five kinds of mixed grass, including Chinese silvergrass, white clover, Bermuda grass, perennial ryegrass and purple flower alfalfa, in the site where the moss has survived, the weight ratio of the seeds is 1:1:1:1:1, and the planting method is to scatter the seeds, and the planting density is 120kg / hm 2 .

[0070] S5 and S6 are the same as in embodiment 1.

[0071] This embodiment solves the problems of loss prevention of acid slag and reduction of acid wastewater, completes the risk control target of 95% loss prevention rate and erosion prevention rate of the historical acid slag left in the site and the ecological restoration target of 90% vegetation coverage. Embodiment 5

[0072] The rapid ecological restoration method of the left smelting slag in this embodiment includes the following steps:

[0073] S1, S2 are the same as in example 1.

[0074] S3, forming a moss survival site: the moss survival site is formed in the rainy season, the moss survival rate is about 80%, and the thickness of the moss skin and accumulated soil layer can reach 4.0-4.3 cm.

[0075] S4, grass seed mixed sowing: in the moss survival site, spring sowing the next year, planting perennial ryegrass and purple flower alfalfa mixed sowing, the weight ratio of seeds is 1:1, the planting method is sowing seeds, and the sowing density is 125 kg / hm 2 .

[0076] S5, S6 are the same as in example 1.

[0077] The embodiment solves the problems of acid waste residue loss prevention and acid waste water reduction, and achieves the risk control target of 90% of the acid waste residue loss prevention rate and the erosion prevention rate of the historical site, and the ecological restoration target of 95% of the vegetation coverage.

[0078] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A quick ecological remediation system of legacy smelting slag, characterized in that: The base rock layer (1), the original soil layer (2) formed by rock weathering, the residual sulfur smelting acid slag (3), the pioneer plant Pogonatum japonicum (4), the moss crust and the accumulated soil layer (5), the mixed grass seeds (6), the pioneer acid-resistant plant Betula alnoides (7) and the culture medium tree species Cryptomeria fortunei (8); The original soil layer (2) formed by rock weathering is located above the base rock layer (1); the residual sulfur smelting acid slag (3) is located above the original soil layer (2) formed by rock weathering; The pioneer plant Pogonatum japonicum (4) is planted on the residual sulfur smelting acid slag (3) before the rainy season, and the mixed grass seeds (6) are mixed and planted in the accumulated soil on the surface of the residual smelting slag in the obtained Pogonatum japonicum survival site; The pioneer acid-resistant plant Betula alnoides (7) and the culture medium tree species Cryptomeria fortunei (8) are planted in the accumulated soil on the surface of the residual sulfur smelting acid slag (3) in the obtained Pogonatum japonicum survival site; The trunks and plants of the obtained Betula alnoides and Cryptomeria fortunei are retained, the branches are cut off within the scope of the repair site, a natural culture medium is formed, the attachment of the pioneer plant Pogonatum japonicum (4) to the historical residual sulfur smelting slag is further promoted, the moss crust and the accumulated soil layer (5) are obtained, and the soil accumulation and the biomass on the surface of the slag are increased.

2. The system of claim 1, wherein: The mixed grass seeds (6) are specifically two or more of the following: Pogonatum japonicum, Lycopodium japonicum, Imperata cylindra, Trifolium repens, Cynodon dactylon, Lolium perenne and Medicago sativa.

3. The system of claim 1, wherein: The planting method of the pioneer acid-resistant plant Betula alnoides (7) and the culture medium tree species Cryptomeria fortunei (8) is to scatter the seeds, germinate this year, and the survival rate is greater than or equal to 75%.

4. A method for rapid ecological remediation of legacy smelting residues, characterized in that: The method comprises the following steps: S1, site leveling: leveling the residual smelting slag in the range needing ecological restoration, the specific method is "high digging and low filling", and a certain slope is formed; S2, Pogonatum japonicum planting: Pogonatum japonicum is planted on the site obtained in step S1 before the rainy season, and indoor cultivation and transplantation or field spore planting are adopted; S3, Pogonatum japonicum survival site formation: the Pogonatum japonicum survival site obtained in step S2, the water retention of Pogonatum japonicum accumulates the water and floating dust in the surrounding environment, and obtains animal acidic metabolites as food for birds and mammals, and the decomposition of acidic slag in the natural environment forms a moss crust and soil, and when the soil thickness accumulates to 2 cm thick, the moss crust rate can reach more than 70%; S4, grass seed mixed planting: two or more of the following are mixed and planted in the accumulated soil on the surface of the historical residual smelting slag in the Pogonatum japonicum survival site obtained in step S3: Pogonatum japonicum, Lycopodium japonicum, Imperata cylindra, Trifolium repens, Cynodon dactylon, Lolium perenne and Medicago sativa, and the planting method is to scatter the grass seeds; S5, arbor planting: two pioneer plants, Betula alnoides and Cryptomeria fortunei, are planted in the accumulated soil on the surface of the historical residual smelting slag in the Pogonatum japonicum survival site obtained in step S3, the planting method is to scatter the seeds, germinate this year, and the survival rate is greater than or equal to 75%; S6, soil and biomass increment: the trunks and plants of the obtained Betula alnoides and Cryptomeria fortunei are retained, the branches are cut off within the scope of the repair site, a natural culture medium is formed, the attachment of the pioneer plant Pogonatum japonicum (4) to the historical residual sulfur smelting slag is further promoted, the soil accumulation and the biomass on the surface of the slag are increased, and the method ends.

5. The method of claim 4, wherein: In S1, the historical smelting slag is excavated and backfilled by excavating machinery, and the high and steep slope formed by long-term rainwater erosion is pushed to eliminate the geological disaster hidden danger; the accumulated slope after the slag excavation is not steeper than 1:3.0, the low-lying range in the site is backfilled by the excavated slag, the backfilled slag needs to be compacted, and the compaction degree is greater than 0.8; after the excavation and backfilling are completed, there should be no water accumulation in the site.

6. The method of claim 4, wherein: In S1, the remaining smelting slag is acid sulfur smelting slag, the accumulation time is more than 40 years, and the surface slag is exposed, the coarse particles account for more than 50% in the particle composition, and the others are mainly in the form of powder and cementation.

7. The method of claim 6, wherein: In S2, the fine particles of waste residue and the moss are mixed and then spread on the repair site. The mixing ratio is 15-20:1, and the spreading amount is 120-135 kg / hm 2 .

8. The method of claim 6, wherein: In S3, the acid sulfur smelting slag is attached with hair moss on the surface to form a moss skin and a soil layer, and the characteristics are that the survival rate of the moss is more than 50%, and the thickness is not less than 2 cm.

9. The method of claim 4, wherein: In S6, the branches are cut to 5-20 cm long and 1-10 cm wide, and are naturally rotten in the natural environment to become the high-quality attachment of S2, wherein the birch trees realize the shrub coverage in the site through the fruits produced by the surviving plants; the cryptomeria trees are reserved according to the regional planning as economic forests, and are only planted around the repaired site when they are natural forests to ensure the biomass of the hair moss.

10. The method of claim 4, wherein: Within 2 years, the "moss-grass-shrub-tree" vegetation layer is realized, the hair moss is survived, attached, skinned and forms the soil layer required for vegetation restoration in the same year, and the "grass-shrub-tree" is survived and grown in the next year.

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