A soil remediation method based on landfill of tailings from laterite nickel ore smelting

Abstract

The invention provides a soil remediation method based on landfill of tailings from laterite nickel ore smelting, including first, carrying out reinforcement treatment in the area of soil to be landed, to lay a base layer at the bottom of the area of soil to be filled; Secondly, the landfill layer is set on the base layer, which includes hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings, and humus; Next, a drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried; Then, a green soil layer is laid on the drainage layer, the green soil is conducive to vegetation growth; Finally, green plants are planted on the green soil layer to complete the soil remediation. The invention firstly improves the soil remediation efficiency by doping the humus and reduces the heavy metal activity in the hydrometallurgy and pyrometallurgy tailings, after that, green plants are planted on the green soil layer to reduce the harm of soil pollution caused by the direct landfill of laterite nickel ore smelting slag.

Description

[0001] Description

[0002] A SOIL REMEDIATION METHOD BASED ON LANDFILL OF TAILINGS FROM LATERITE NICKEL ORE SMELTING

[0003] Field Of Disclosure

[0004] The invention relates to the technical field of tailings treatment , and in particular to a soil remediation method based on landfill of tailings from laterite nickel ore smelting .

[0005] Background

[0006] The raw material grade of laterite nickel ore is only about 1 % to 3% , and the slag ratio in the smelting process is large . With the gradual expansion of the scale o f high-pressure acid leaching of laterite nickel ore or pyrometallurgical smelting of nickel-iron alloy, the emission of pyrometallurgical nickel ore tailings has gradually increased . At present , the smelting nickel ore tailings after landfill ecological remediation directly planting plants , direct plant easy to landfill area of soil loss , reduce plant survival , at the same time reduce microbial and animal capacity, is not conducive to vegetation growth, lead to landfill area soil cannot become ecological remediation, causing serious environmental pollution .

[0007] Summary

[0008] The purpose of present invention is to provide a soil remediation method based on landfill of tailings from laterite nickel ore smelting, which is used to improve the technical problem of soil pollution around the landfill area caused by direct landfill treatment of nickel ore smelting tailings .

[0009] In order to solve the above technical problems , present invention provides a soil remediation method based on landfill of tailings from laterite nickel ore smelting, comprising :

[0010] S 10 . The area of soil to be filled is reinforced first to lay a base layer at the bottom of the area of soil to be filled; S20. A landfill layer is set on the base layer, which includes hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings, and humus soil;

[0011] S30. A drainage layer is provided on the landfill layer, and the drainage layer is connected to the drainage ditch around the soil area to be landfilled;

[0012] S40. A green soil layer is laid on the drainage layer. The soil in the green soil layer is conducive to the growth of vegetation;

[0013] S50. Green plants are planted on the green soil layer to complete soil remediation.

[0014] Preferably, in step S10, the material of the base layer includes at least one infrastructure soil, crushed stone, gravel, and ceramsite .

[0015] Preferably, before performing step S20, the process further includes cooling the hydrometallurgical nickel ore tailings for 2 to 7 days .

[0016] Preferably, the S20 step specifically includes:

[0017] 5201. Laying hydrometallurgical nickel ore tailings on the base to obtain a first tailings layer;

[0018] 5202. Laying pyrometallurgical laterite nickel ore tailings on the first tailings layer to obtain a second tailings layer;

[0019] 5203. laying humus soil on the second tailings layer to obtain a humus layer.

[0020] Preferably, the sum of the thickness of the first tailings layer and the second tailings layer is less than the thickness of the humus layer .

[0021] Preferably, the S20 step specifically includes:

[0022] S201 . Laying a landfill layer on the base layer, the landfill layer is a mixture of hydrometallurgical laterite nickel ore tailings, pyrometallurgical laterite nickel ore tailings, and humus soil.

[0023] Preferably, the mass ratio of hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings, and humus in the landfill is (6-8) : 1 : (1-3) .

[0024] Preferably, in step S20, the humus soil comprises, by weight: 60-80 parts of humic acid, 20-30 parts of corn straw powder, and 5-10 parts of activated carbon powder. Preferably, in step S30 , a geocomposite drainage net is provided in the drainage layer, and the permeability coef ficient of the geocomposite drainage net is greater than l x l 0~2m / s .

[0025] Preferably, in step S40 , the thickness of the compacted greening soil layer is greater than 20 cm .

[0026] The beneficial ef fects of the present invention are as follows : Di f ferent from the prior technique , present invention provides a soil remediation method based on landfill of tailings from laterite nickel ore smelting, comprising : firstly, reinforcing the soil area to be landfilled to lay a base layer at the bottom of the soil area to be landfilled; secondly, a landfill layer is set on the base layer, which includes hydrometallurgical nickel ore tailings , pyrometallurgical nickel ore tailings , and humus soil ; thirdly, a drainage layer is set on the landfill layer, and the drainage layer is connected to the drainage ditch around the soil area to be landfilled; then, a green soil layer is laid on the drainage layer, and the soil in the green soil layer is conducive to the growth of vegetation; finally, green plants are planted on the green soil layer to complete soil remediation . The present invention firstly designs a base layer to reinforce the soil area to be landfilled, then mixes humus into the landfill layer to improve the soil remediation ef ficiency and reduce the heavy metal activity in the hydrometallurgical nickel ore tailings and the pyrometallurgical laterite nickel ore tailings , then sets a drainage layer to drain the excess liquid in the soil area to be landfilled, and finally plants green plants on the green soil layer to reduce the pollution hazard of the pyrometallurgical nickel ore tailings to the soil after direct landfill .

[0027] Brief Description Of The Drawings

[0028] FIG . 1 is a flow chart of a soil remediation method based on landfill of tailings from laterite nickel ore smelting provided by present invention . Detailed Description Of Preferred Embodiments

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention . The described embodiments are only part of the embodiments of the present invention, rather than all the embodiments . Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention .

[0030] Given the technical problem that the existing pyrometallurgical nickel ore tailings cause soil pollution around the landfill area due to direct landfill treatment , the present invention provides a soil remediation method based on landfill of tailings from laterite nickel ore smelting, which can solve the above technical problem .

[0031] Please refer to FIG . 1 , which is a flow chart of a soil remediation method based landfill of tailings from laterite nickel ore smelting provided by the present invention; wherein the soil remediation method comprises :

[0032] S 10 . Reinforcing the soil area to be landfilled, to lay a base layer at the bottom of the soil area to be landfilled .

[0033] Speci fically, the S 10 step also includes : Firstly, select the soil area to be filled and level the site in its border area to facilitate construction .

[0034] Secondly, clean up the loose bodies in the soil area to be filled . Cleaning up the loose bodies is to eliminate potential unstable factors , avoid collapse , slippage , and other problems during subsequent construction and use , and ensure the stability of the foundation of the soil area to be filled .

[0035] Finally, the area to be filled is reinforced by laying a base layer at the bottom of the area to be filled to prevent the soil in the area to be filled from settling or slope down . Laying the base layer or reinforcement structure provides a solid bearing platform, which helps to evenly disperse the upper pressure and also creates good basic conditions for subsequent landfill and planting work .

[0036] Preferably, the material of the base layer includes at least one of infrastructure soil , crushed stone , gravel and ceramsite ; wherein, when the base layer material includes infrastructure soil , infrastructure soil , as a relatively common and basic soil type , has a certain bearing capacity and stability, and can provide preliminary support and foundation; the addition of gravel can signi ficantly enhance the strength and stability of the base layer . The gravel has high hardness and compression resistance , which can ef fectively disperse the pressure from the upper part and reduce the risk of settlement and deformation; at the same time , the gaps in the gravel help drainage and ventilation, and improve the hydraulic properties of the base layer ; Gravel also has good drainage performance and a certain bearing capacity . It can work together with crushed stone to further optimi ze the structure of the base , improve drainage ef ficiency, and prevent the adverse ef fects caused by water accumulation; The characteristics of expanded clay are lightweight and high porosity, which reduces the weight of the base layer while ensuring a certain strength . It is very suitable for occasions with special requirements on weight . Its porosity can also improve the air permeability and water retention of the base layer .

[0037] S20 . Setting a landfill layer on the base layer, the landfill layer comprising hydrometallurgical nickel ore tailings , pyrometallurgical nickel ore tailings , and humus .

[0038] Speci fically, the S20 step also includes :

[0039] First , the hydrometallurgical nickel ore tailings are cooled for 2 to 7 days , preferably 3 to 4 days ; wherein the hydrometallurgical nickel ore tailings are solid waste residues produced by dissolving valuable metals such as nickel in the laterite nickel ore into a solution under high pressure and strong acid conditions ; from the composition point of view, the tailings of the hydrometallurgical laterite nickel ore process usually contain some metal elements and their compounds , such as nickel , iron, magnesium, etc . , and may also contain other impurities . From the physical property point of view, it is generally in the form of fine particles . The amount of waste produced is usually large , and i f it is not handled properly, it will cause certain harm to the environment , such as occupying land resources and possibly polluting the surrounding soil , water, and atmosphere through dust or leachate . Speci fically, cooling the hydrometallurgical nickel ore tailings can reduce its temperature to a range more suitable for subsequent operations , reducing the adverse ef fects of high temperature on other materials and construction processes . After a certain period of cooling, the physical and chemical properties of the hydrometallurgical nickel ore tailings are more stable .

[0040] Afterward, a landfill layer is arranged on the base layer, and the landfill layer includes cooled hydrometallurgical nickel ore tailings , pyrometallurgical nickel ore tailings , and humus .

[0041] Among them, pyrometallurgical laterite nickel ore tailings are the remaining waste slag produced after laterite nickel ore is treated by the pyrometallurgical process . In addition to a small amount of underutili zed nickel and other metal elements , it may also contain other minerals and compounds formed during high-temperature processes .

[0042] In the embodiment of the present invention, the humus soil comprises , by weight : 60- 80 parts of humic acid, 20-30 parts of corn straw powder, and 5- 10 parts of activated carbon powder .

[0043] Speci fically, humic acid contains active functional groups such as hydroxyl , phenolic hydroxyl and quinone groups , and has hydrophilicity, adsorption, ion exchange , complexation, redox and biological activity . Humic acid can undergo various chemical reactions such as adsorption, ion exchange , redox, complexation, and chelation with water-soluble and adsorbed bioavailable heavy metal ions , causing the heavy metal ions to be fixed by complexation and chelation or adsorption, thereby reducing the bioavailability of heavy metal ions and the amount absorbed by plants .

[0044] Speci fically, the addition of corn stalk powder increases the source of organic matter in humus soil . After decomposition, corn stalk powder can provide certain nutrients to the soil , while helping to improve the soil ' s aggregate structure and increase soil permeability and water permeability;

[0045] Activated carbon powder has a strong adsorption capacity and can adsorb harmful substances such as heavy metal ions and organic pollutants in the soil to puri fy the soil . It can also adj ust the pH value of the soil and improve the soil environment . In the first embodiment , step S2 speci fically includes : 5201 . Laying hydrometallurgical nickel ore tailings on the base to obtain a first tailings layer ;

[0046] 5202 . Laying pyrometallurgical laterite nickel ore tailings on the first tailings layer to obtain a second tailings layer ;

[0047] 5203 . Laying humus soil on the second tailings layer to obtain a humus layer .

[0048] Speci fically, laying the three materials in three layers has many meanings . Hydrometallurgical nickel ore tailings and pyrometallurgical laterite nickel ore tailings usually contain certain mineral components , but may also contain some pollutants . By combining with humus soil , the overall soil texture and fertility can be improved and heavy metals can be removed . Laying in three layers can better control the characteristics and proportions of each layer to achieve the best remediation ef fect .

[0049] Preferably, the sum of the thickness of the first tailings layer and the second tailings layer is less than the thickness of the humus layer ; wherein, when the sum of the thickness of the first tailings layer and the second tailings layer is less than the thickness of the humus layer, the following benefits may be achieved : from the perspective of soil structure and function, a thicker humus layer can provide richer organic matter and nutrients , which is beneficial to plant growth and microbial activity . Humus can improve the physical and chemical properties of the soil , enhance the soil ' s ability to retain water and fertili zer, and its air permeability, etc . , creating more favorable conditions for the development of plant roots . The relatively thin first and second tailings layers can reduce the potential adverse ef fects of harmful substances that may exist in the tailings on the entire soil system, and also facilitate better control of the characteristics and ef fects of the tailings . The thicker humus layer on the surface can better interact with the external environment , such as absorbing precipitation and exchanging gases with the atmosphere , thereby promoting the stability and development of the soil ecosystem .

[0050] In the second embodiment , the S20 step speci fically comprises :

[0051] S201 . laying a landfill layer on the base layer, the landfill layer is a mixture of hydrometallurgical nickel ore tailings , pyrometallurgical nickel ore tailings , and humus soil . Speci fically, the utili zation of hydrometallurgical nickel ore tailings and pyrometallurgical nickel ore tailings avoids the waste of resources and environmental pressure caused by direct waste disposal and reali zes the recycling of waste . The addition of humus can improve the physical and chemical properties of the landfill layer, increase soil fertility and organic matter content , and remove heavy metals , thereby contributing to plant growth and the establishment of an ecosystem . By mixing the three materials and then laying them down, the three materials can be more fully integrated and exert a synergistic ef fect .

[0052] Speci fically, in the landfill layer, the mass ratio of hydrometallurgical nickel ore tailings , pyrometallurgical nickel ore tailings and humus is ( 6 ~ 8 ) : 1 : ( 1 ~ 3 ) , preferably 7 : 1 : 2 ; wherein, hydrometallurgical nickel ore tailings and pyrometallurgical nickel ore tailings are mixed in a larger proportion, which not only reali zes the comprehensive utili zation of these two wastes and reduces their potential harm to the environment , but also can construct a landfill layer with the help of their respective characteristics . For example , pyrometallurgical laterite nickel ore tailings may provide certain structural stabil ity, while hydrometallurgical nickel ore tailings may have some special chemical properties . At the same time , the existence of humus soil highlights its importance . Humus soil is rich in organic matter and nutrients , which can signi ficantly improve soil fertility, air permeability, and water retention of the landfill layer, laying a good foundation for subsequent plant growth and ecosystem recovery .

[0053] S30 . Setting a drainage layer on the landfill layer, wherein the drainage layer is connected to drainage ditches around the soil area to be landfilled .

[0054] Speci fically, the S30 step also includes :

[0055] The drainage layer is set on the landfill layer, and the drainage layer is connected to the drainage ditches around the landfill area . Among them, setting up the drainage layer is very critical , which can ef fectively drain excess water, and prevent soil waterlogging from causing plant root rot and other possible environmental problems . At the same time , good drainage also helps the exchange of gas in the soil , and promotes microbial activity and plant growth . Preferably, the drainage layer uses a 6-10 mm geocomposite drainage net, and the permeability coefficient should be greater than lxl0~2m / s . The geocomposite drainage net material should have sufficient water conductivity.

[0056] S40. A greening soil layer is laid on the drainage layer, and the soil of the greening soil layer is conducive to the growth of vegetation .

[0057] Specifically, the S4 step also includes:

[0058] A greening soil layer is laid on the drainage layer. The soil of the greening soil layer is conducive to the growth of vegetation. The thickness of the compacted greening soil layer is greater than 20 cm.

[0059] Specifically, the soil in the greening layer is conducive to vegetation growth, which is very important for ecological remediation and environmental beautification. Soil suitable for vegetation growth can provide the basic conditions such as nutrients, water, and air required by plants, promote plant rooting, growth, and development, help form rich and diverse vegetation communities, and enhance the ecological diversity and landscape effects of the region.

[0060] Specifically, the thickness of the compacted greening soil layer is greater than 20 cm, which has the following benefits: firstly, it can provide sufficient growth space for the roots of vegetation, so that the roots of plants can better stretch and take root, and enhance the stability and wind resistance of plants; secondly, the thicker soil layer can better retain water and nutrients, reduce water evaporation and nutrient loss, and provide continuous support for the long-term growth of plants; thirdly, it can play a certain isolation and protection role, reducing the impact of external factors (such as temperature fluctuations, mechanical damage, etc.) on the lower drainage layer and other structures.

[0061] S50. Green plants are planted on the green soil layer to complete soil remediation.

[0062] Specifically, the S50 step also includes:

[0063] Greening plants are planted on the greening soil layer to complete soil remediation . Greening plants include banana trees, cannas, etc., planting plants, especially banana trees, cannas, etc., can not only beautify the environment but more importantly, the roots of the plants can fix the soil and enhance the stability of the soil. The growth process of the plants can also absorb and transform some harmful substances, further promoting the ecological remediation of the soil .

[0064] The technical scheme of this application is now described in combination with the specific embodiments.

[0065] Example 1 :

[0066] Example 1 of the present invention provides a soil remediation method based landfill of tailings from laterite nickel ore smelting, and the above soil remediation method specifically includes:

[0067] (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0068] (2) . The hydrometallurgical tailings of laterite nickel ore are cooled for 3 days and then set aside, and the laterite nickel ore tailings are leached by high-pressure acid leaching slag of laterite nickel ore;

[0069] (3) . The cooled hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings and humus soil are laid in three layers; the pyrometallurgical nickel ore tailings are smelting by rotary kiln electric furnace process; the laterite tailings are smelting by rotary kiln electric furnace; the laying thickness of laterite tailings is 0.7 m, the laying thickness is 0.1 m, and the thickness of humus is 0.2 m. The humus includes 60 parts of humic acid, 30 parts of corn straw powder, and 10 parts of activated carbon powder;

[0070] (4) . The drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried. The drainage layer is an 8 mm geotechnical composite drainage network, with a permeability coefficient of 2xl0~2m / s;

[0071] (5) . Lay a layer of green soil layer on the drainage layer, and the thickness of the green soil layer is 0.5 m;

[0072] (6) . Plant banana trees on the green soil layer to complete the soil remediation.

[0073] Example 2 :

[0074] Example 2 of the present invention provides a soil remediation method based on smelting tailings landfill in laterite nickel ore, and the above soil remediation method specifically includes: (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0075] (2) . The cooled hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings, and humus are laid in three layers; among them, the slag of the laterite nickel ore is smelting by the rotary kiln; the laying thickness of hydrometallurgical tailings of laterite is 0.7 m, that of 0.1 m, and that of humus is 0.2 m: humic acid, 30 parts of corn straw powder and 10 parts of activated carbon powder;

[0076] (3) . The drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried. The 8 mm geotechnical composite drainage network is selected for the drainage layer, with a permeability coefficient of 2xl0~2m / s;

[0077] (4) . Lay a layer of green soil layer on the drainage layer, and the thickness of the green soil layer is 0.5 m;

[0078] (5) . Plant banana trees on the green soil layer to complete the soil remediation.

[0079] Example 3:

[0080] Example 3 of the present invention provides a method of soil remediation based landfill of tailings from laterite nickel ore smelting, and the above soil remediation method specifically includes :

[0081] (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0082] (2) . The hydrometallurgical tailings of laterite nickel ore is cooled for 3 days, and the tailings of laterite nickel ore is extracted by high-pressure acid;

[0083] (3) . Lay a layer of landfill layer after mixing the cooled hydrometallurgical nickel ore tailings, pyrometallurgical nickel ore tailings, and humus soil according to the mass ratio of 7:1:2; Among them, the pyrometallurgical laterite nickel ore tailings; the laying thickness of the landfill layer is 1 m, including humic acid, 30 parts of corn straw powder and 10 parts of activated carbon powder; (4) . The drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be filled. The drainage layer is an 8 mm geotechnical composite drainage network, with a permeability coefficient of 2xl0~2m / s;

[0084] (5) . Lay a layer of green soil layer on the drainage layer, and the thickness of the green soil layer is 0.5 m;

[0085] (6) . Plant banana trees on the green soil layer to complete the soil remediation.

[0086] Comparative Example 1 :

[0087] A soil remediation method is provided for comparation 1 based on pyrometallurgical tailings landfill of the soil comprising:

[0088] (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0089] (2) . Lay a landfill layer after mixing the cooled hydrometallurgical laterite nickel tailings and the laying thickness of the landfill layer is 1 m;

[0090] (3) . Lay a layer of green soil layer on the landfill layer, and the thickness of the green soil layer is 0.5 m.

[0091] Comparative Example 2 :

[0092] A soil remediation method is provided for proportion 2 based on smelting tailings landfill, the above soil remediation method comprising :

[0093] (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0094] (2) . Lay a landfill layer after mixing the hydrometallurgical laterite nickel tailings and the laying thickness of the landfill layer is 1 m;

[0095] (3) . The drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried. The drainage layer is an 8 mm geotechnical composite drainage network, with a permeability coefficient of 2x10-2 m / s; (4) . Lay a layer of green soil layer on the drainage layer, and the thickness of the green soil layer is 0.5 m;

[0096] Comparative Example 3:

[0097] A soil remediation method is provided for proportion 3 based on smelting tailings landfill of the soil comprising:

[0098] (1) . Clean the loose body and lay the soil area to fill the base. The material of the base is infrastructure soil, and the thickness of the base is 0.5 m;

[0099] (2 ) . Lay a landfill layer after mixing hydromet al lurgi cal laterite nickel tailings and the laying thickness of the landfill layer is 1 m;

[0100] (3) . The drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried. The drainage layer is an 8 mm geotechnical composite drainage network, with a permeability coefficient of 2xl0~2m / s;

[0101] (4) . Lay a layer of green soil layer on the drainage layer, and the thickness of the green soil layer is 0.5 m;

[0102] (5) . Plant banana trees on the green soil layer to complete the soil remediation.

[0103] After 1 year, the solid waste leaching toxicity test of the soil samples in the landfill area of the embodiments 1 to 3 and the ratio 1 to 3, and the results are shown in Table 1 respectively:

[0104] Table 1 Exaching toxicity test results of the soil in the proportion 1 to 3 (the actual measured content is much less than 0.001, marked "ND" in the table) Speci fically, as is known from Table 1 , the contents of Ni , Cu, Zn and Cr6+in the aching toxicity test results of the soil of the present invention are less than or equal to 2 . 75 ppm, and Pb and Cd are not detected; Ni , Cu, Zn, Pb and Cr6+were detected in the ratio of 1 to 3 , and the content of Ni was greater than or equal to 7 . 65 ppm, and the content of Zn was greater than or equal to 0 . 54 ppm .

[0105] Therefore , the landfill area of pyrometallurgical laterite nickel tailings treated in embodiments 1 to 3 of the invention has fewer heavy metal residues than 1 to 3 , which can ef fectively reduce the pollution hazard caused by the landfill of pyrometallurgical laterite nickel tailings .

[0106] In conclusion, the present invention provides a soil remediation method based on landfill of tailings from laterite nickel ore smelting, which includes : first , reinforce the landfill soil area to lay the base at the bottom of the soil area to be buried; second, set the landfill layer on the base level , including the hydrometallurgical tailings of laterite nickel ore , pyrometallurgical laterite nickel ore tailings and humus ; Thirdly, a drainage layer is set on the landfill layer, which is connected with the drainage ditch around the soil area to be buried; Thirdly, laying a green soil layer on the green soil is conducive to vegetation growth; finally, plant green plants on the green soil layer to complete soil remediation . The present invention first designed the base layer to reinforce the soil area to be buried, and then by doping humus soil in the landfill layer to improve the soil remediation ef ficiency and reduce the activity of heavy metals in hydrometallurgical nickel ore tailings and pyrometallurgical nickel ore tailings , Then, the drainage layer is set up to discharge the excess liquid in the soil area to be buried, and finally, the green plants are planted on the green soil layer to reduce the pollution harm to the soil after direct landfill of laterite nickel smelting tailings .

[0107] It should be noted that the above embodiments belong to the same invention idea, the description of each embodiment has the emphasis , not detailed in individual embodiments , and can refer to the description in other embodiments .

[0108] The above embodiments only express the embodiment of the invention, which is more speci fic and detailed but cannot be understood as a limitation on the scope of the invention patent . It should be noted that for those skilled in the technique , several trans formations and improvements can be made without departing from the idea of the present invention, which all fall within the protection scope of the present invention . Therefore , the scope of protection of the invention patent shall be subj ect to the attached claims .

Claims

What Is Claimed Is1 . A soil remediation method based on landfill of tailings from laterite nickel ore smelting, which is characteri zed by :S 10 . Reinforce the landfill soil area to lay the base at the bottom of the soil area to be landfilled;S20 . A landfill layer is provided on the base layer, including hydrometallurgical nickel laterite tailings , pyrometallurgical laterite nickel tailings , and humus ;S30 . Set up the drainage layer on the landfill layer, the drainage layer is connected to a drainage ditch around the area of the soil to be filled;S40 . Laying a green soil layer on the said drainage layer, the soil of the green soil layer is conducive to vegetation growth;S50 . Plant green plants on the green soil layer to complete the soil remediation .2 . The soil remediation method based on the landfill of smelting tailings as described in claim 1 , wherein the material of the base layer comprises at least one of the construction soil , gravel , and ceramsite .3 . The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 1 , wherein that , before the S20 step further includes : the laterite nickel ore hydrometallurgical tailings were cooled with a cooling time of 2~7 days .4 . The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 3 , wherein that , before the S20 step further includes :5201 . Laying the hydrometallurgical laterite nickel ore tailings on the base layer to obtain a first tailings layer ;5202 . On the first tailings layer, the pyrometallurgical laterite nickel ore tailings are laid to obtain a second tailings layer ;5203 . Laying the humus soil on the second tailings layer to obtain the humus layer .

5. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 4 is characterized in that the total of the thickness of the first tailings layer and the second tailings layer is less than the thickness of the humus layer .

6. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 3 is characterized in that the step S20 specifically comprises:S201. A landfill layer is laid on the base layer, and the landfill layer is formed by mixing the hydrometallurgical laterite nickel ore tailings, the pyrometallurgical laterite nickel ore tailings and the humus soil.

7. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 6, wherein in the landfill layer, the mass ratio of the hydrometallurgical laterite nickel ore tailings, the pyrometallurgical laterite nickel ore tailings and the humus is (6~8) :1: (1~3) .

8. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 1 is characterized in that, in the step S20, the humus soil comprises, by weight: 60-80 parts of humic acid, 20-30 parts of corn straw powder, and 5-10 parts of activated carbon powder.

9. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 1 is characterized in that, in the step S30, a geocomposite drainage net is provided in the drainage layer, and the permeability coefficient of the geocomposite drainage net is greater than lxl0~2m / s .

10. The soil remediation method based on landfill of tailings from laterite nickel ore smelting according to claim 1, wherein in the S40 step, the thickness of the compacted green soil layer is greater than 20 cm.

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