Tailing damming material for modifying tailings based on curing agent and damming method of tailing damming material

Abstract

The invention discloses a tailing damming material for modifying tailings based on a curing agent, which is prepared by taking tailings as a main body material, adding the curing agent, water and an auxiliary additive into the tailings, and modifying the tailings according to a designed ratio. The low-strength modified tailing damming material with the mechanical properties of natural earth and stone materials or the high-strength modified tailing damming material with concrete is obtained; the curing agent mainly comprises the following components in percentage by weight: 30-50% of a plasticizer, 30-50% of a reinforcing agent and 10-12% of others; the auxiliary additive comprises fly ash, slag powder and silica fume. The method has the advantages that the comprehensive performance of the dam body is improved, the construction steps are simplified, the damming efficiency is improved, the requirements of various low-strength or high-strength dam bodies can be met, and high efficiency and environment friendliness are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of tailings damming, and in particular relates to a tailings damming material based on tailings modification by a curing agent and a damming method thereof. Background Art

[0002] Tailings refer to industrial and mining solid wastes discharged by ore dressing plants after grinding the ore and selecting the useful components, including copper, gold, iron, lead and zinc tailings and other tailings that are not hazardous wastes. When building a dam at a tailings dump, it is usually necessary to excavate the mountain to obtain soil and build the dam with stones, which not only causes certain damage to the environment, but also the traditional concrete tailings dam has insufficient anti-seepage capacity, which easily causes the tailings dump sewage to leak and pollute the environment.

[0003] In addition, in response to the requirements of dam construction under different objective environments, some require the construction of low-strength dams such as earth-rock dams, while others require the construction of high-strength gravity dams such as concrete dams, mortar-stone dams, buried stone concrete dams, and seepage-cutting dams. Based on the policy guiding principles of energy conservation and carbon reduction, and waste treatment, on-site use of tailings to build dams is the best option. However, when using tailings to build dams, the tailings need to be processed to varying degrees, and the process is relatively cumbersome, which reduces the efficiency of dam construction, and the comprehensive performance of the tailings dam may also be relatively unstable. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of complicated existing tailings dam construction procedures, low dam construction efficiency, poor anti-seepage effect and stability of the dam body, and to provide a tailings dam construction material based on tailings modification by a curing agent, which can improve the comprehensive performance of the dam body, simplify the construction steps, and improve the dam construction efficiency. It can adapt to various low-strength or high-strength dam body requirements and is efficient and environmentally friendly.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A tailings dam material based on tailings modification by a curing agent, comprising tailings as a main material, adding a curing agent, water and auxiliary additives to the tailings, and modifying the tailings according to a designed ratio to obtain a low-strength modified tailings dam material with the mechanical properties of natural soil and stone materials or a high-strength modified tailings dam material equivalent to C20-C30 concrete; The main components and percentages of the curing agent include: superplasticizer: 30-50%, reinforcing agent: 30-50%, and others: 10%-12%; the auxiliary additives include fly ash, slag powder and silica fume.

[0006] Furthermore, the content of the tailings is not less than 75%, and the amount of cement added with a curing agent of 0.5-3% and the design ratio of auxiliary additives are controlled so that the modified tailings material obtains mechanical property indicators greater than or equal to those of natural soil and stone, forming a low-strength modified tailings dam building material for use in building tailings dams.

[0007] Furthermore, the permeability coefficient of the dam body built with low-strength tailings dam material is K≤1.0×10 -5 ~1.0×10 -7 cm / s, with environmental protection and anti-seepage capabilities.

[0008] Furthermore, the content of the tailings is not less than 65%, and the amount of cement added with a curing agent of 1-5% and the design ratio of auxiliary additives are controlled, so that the modified tailings material obtains mechanical property indicators greater than or equal to those of traditional concrete, forming a high-strength modified tailings dam material, and there is no need to add traditional crushed stone aggregate to this modified tailings dam material.

[0009] Furthermore, the mechanical strength of the tailings pond gravity dam constructed with high-strength modified tailings dam building materials includes but is not limited to reaching the normal concrete strength C20, C25, C30 and above, so that it can be used to build gravity dams such as concrete gravity dams, buried stone concrete dams or cut-off dams, and can also be used for the construction of retaining dams for other industrial slag ponds.

[0010] In order to further achieve the purpose of the present invention, a dam-building method of tailings dam-building materials based on tailings modified by a curing agent is also provided, and the specific steps are as follows, including: (1) Carry out initial dam construction directly at the selected dam site and perform foundation clearing or dam foundation treatment in accordance with the specifications; (2) After treatment, earth-rock dam construction equipment is used on site to spread, layer, compact and roll the low-strength modified tailings dam material, where the layer thickness is 15~40cm, the compressive strength includes but is not limited to 0.25~2.00MPa, and the internal friction angle φ≥22°; (3) The dam body constructed with low-strength modified tailings dam material has mechanical properties equal to or higher than those of natural earth-rock dam body, and the dam body has anti-seepage performance that meets environmental protection requirements: K≤1.0×10 -5 ~1.0×10 -7 cm / s.

[0011] Furthermore, the dam-building method of tailings dam-building materials based on tailings modified by a curing agent comprises the following specific steps: (1) Clean the foundation or treat the dam foundation according to the specifications, and first construct a low dam with a natural earth-stone foundation at the selected dam site; (2) After a certain amount of tailings is blocked by a basic low dam, the tailings are mixed with a solidifying agent to obtain a low-strength modified tailings dam-building material, and the low-strength modified tailings dam-building material is used on the basic low dam to construct and raise the dam body; (3) Spread, layer, compact and roll the low-strength modified tailings dam material on site, where the layer thickness is 15~40cm, the compressive strength includes but is not limited to 0.25~2.00MPa, and the internal friction angle φ≥22°; (4) The final dam body has mechanical properties similar to those of a natural earth-rock dam body, and the dam body anti-seepage capacity K≤1.0×10 -5 ~1.0×10 -7 cm / s.

[0012] Furthermore, in step (1), the height H of the low dam is 5.0-10.0 m, but is not limited to this range, and the top width B of the low dam is ≥3 m.

[0013] Furthermore, the dam-building method of tailings dam-building materials based on the modification of tailings with a curing agent has the following specific steps, including using high-strength modified tailings dam-building materials to build a gravity dam, and the dam-building method adopts traditional concrete mixing, pouring, and curing to modify the tailings into high-strength modified tailings dam-building materials for building traditional concrete dams, mortar-masonry dams, buried stone concrete dams, and seepage-cutting dams in tailings ponds. Such gravity dams, and the anti-seepage capacity of the dam body meets the requirements of national environmental protection standards.

[0014] Compared with the prior art, the advantages of the technical solution of the present invention are: (1) The low-strength modified tailings dam material of the present invention is used for the construction of similar earth-rock dams and is easy to construct: it can be spread, layered, rolled, excavated, and backfilled for convenient construction. The constructed tailings dam has environmental protection and anti-seepage properties. The use of tailings modified materials to build dams can avoid large-scale excavation of mountains to obtain soil and stone to build dams, thereby avoiding environmental damage; the dam body has an anti-seepage capacity that meets the requirements of national standards, avoiding the leakage of sewage from the tailings yard to pollute the environment; (2) The high-strength modified tailings dam material of the present invention is used to construct a concrete dam and is easy to construct: it is completely similar to the pouring and paving construction of traditional concrete; and because the modified material does not need to add traditional crushed stone aggregate, a large amount of mountain quarrying can be avoided. This can avoid the large-scale use of traditional concrete, achieve low-carbon and environmental protection, and the constructed tailings dam has environmental protection and anti-seepage performance; (3) The low-strength modified tailings dam material of the present invention is used to build a tailings dam with natural earth and stone materials, and the high-strength modified tailings dam material is used to build a gravity dam. The construction process is the same as that of traditional earth and stone dams and gravity dams, but the mechanical properties are adjustable, the construction method is simple, the economic cost is low, the operability is strong, and it has significant environmental, social and economic value. DETAILED DESCRIPTION Example 1

[0015] To make the present invention more clear, the following further describes a tailings damming material based on tailings modification by a curing agent and a damming method thereof. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] In the present invention, by adding a new type of curing agent, water, other auxiliary additives, etc. to the tailings and fully stirring them, "modified tailings soil material" and "modified tailings concrete material" are obtained, that is, the corresponding low-strength modified tailings dam building material and high-strength modified tailings dam building material, both of which have corresponding engineering mechanical properties, and their mechanical index values ​​can be achieved by adjusting the proportion of the curing agent to achieve the bulk density γ value, cohesion C value, internal friction angle φ value required by the tailings dam designer, and the permeability coefficient K value that meets the national environmental protection standards.

[0017] In this embodiment, the main material contains 85% copper tailings ultra-fine sand, 3% cement, 10% fly ash, 0.5% curing agent, and a water-binder ratio of 0.5, and a modified tailings dam material with a 28-day compressive strength of 1.2 MPa is obtained.

[0018] The above-mentioned "modified tailings soil" can be used to directly carry out initial dam construction at the selected dam site after clearing the foundation or treating the dam foundation according to the specifications. The "modified tailings soil" can be spread, layered, compacted and rolled using traditional earth-rock dam construction equipment on site. The layer thickness is 15~40cm, and its 28-day compressive strength is 1.2MPa, and the internal friction angle φ≥22°. The mechanical properties of the dam body are similar to or higher than those of the natural earth-rock dam body, and the dam body has anti-seepage properties that meet environmental protection requirements: K≤1.0×10 -6 cm / s. Example 2

[0019] In this embodiment, the main material contains 85% lead-zinc tailings slag (particle size: 0.075-10 mm), 3% cement, 2% slag powder, 5% fly ash, 0.5% curing agent, and a water-binder ratio of 0.42, and the modified tailings dam material with a 28-day compressive strength of 1.8 MPa is obtained.

[0020] Using the above-mentioned "modified tailings soil", a natural earth-rock foundation dwarf dam can be constructed at the selected dam site after clearing the foundation or treating the dam foundation according to the specifications. The height of the dwarf dam is H = 5.0~10.0m, but not limited to this range. The dam crest width B ≥ 3m. After a certain amount of tailings is blocked by the basic dwarf dam, the tailings and the curing agent are mixed to obtain "modified tailings soil". On this basic dwarf dam, the "modified tailings soil" is used to construct and raise the dam body to obtain mechanical properties similar to those of the natural earth-rock dam body. The "modified tailings soil" can be used for paving, layering, compacting, and rolling on site. The layer thickness is 15~40cm, and its 28-day compressive strength is: 1.8MPa, and the internal friction angle φ ≥ 22°. At the same time, the dam body anti-seepage capacity K ≤ 6.0×10 -7 cm / s. Example 3

[0021] In this embodiment, a high-strength modified tailings dam material is obtained by using 70% of copper tailings fine sand, 12% of cement, 8% of slag powder, 8% of fly ash, 1.5% of curing agent, and a water-binder ratio of 0.32, and the "modified tailings concrete material" has similar performance to that of a concrete dam. The 28-day compressive strength of the concrete is 32 MPa.

[0022] The above-mentioned "modified tailings concrete material" is used to build a gravity dam. The construction method of the dam is traditional concrete mixing, pouring and curing. The tailings are modified into "modified tailings concrete material" to build traditional concrete dams, mortar masonry dams, buried stone concrete dams, seepage interception dams and other gravity dams in the tailings pond, and the anti-seepage capacity of the dam body meets the requirements of national environmental protection standards. This is not limited to tailings ponds, and can also be used to build retaining dams in other industrial waste slag ponds.

[0023] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A tailings dam material based on tailings modified by a curing agent, characterized in that: It includes taking tailings as the main material, adding cementitious materials, curing agents, water and auxiliary additives to the tailings, and modifying the tailings according to the designed proportion to obtain low-strength modified tailings dam-building materials with the mechanical properties of natural soil and stone materials or high-strength modified tailings dam-building materials with concrete; The main components and percentages of the curing agent include: superplasticizer: 30-50%, reinforcing agent: 30-50%, and others: 10%-12%; the auxiliary additives include fly ash, slag powder and silica fume.

2. The tailings damming material based on the modification of tailings by a curing agent according to claim 1, characterized in that: The content of the tailings is not less than 75%, and the curing agent is controlled to be 0.5-3% of the cement dosage and the designed proportion of auxiliary additives, so that the modified tailings material obtains mechanical property indicators greater than or equal to those of natural soil and stone, forming a low-strength modified tailings dam material.

3. The tailings damming material based on the modification of tailings by a curing agent according to claim 2, characterized in that: The permeability coefficient of the dam body built with low-strength tailings dam material is K≤1.0×10 -5 ~1.0×10 -7 cm / s.

4. The tailings damming material based on the modification of tailings by a curing agent according to claim 1, characterized in that: The content of the tailings is not less than 65%, and the curing agent is controlled to be 1-5% of the cement dosage and the designed proportion of auxiliary additives, so that the modified tailings material obtains mechanical property indicators greater than or equal to those of traditional concrete, forming a higher strength modified tailings dam building material, and the modified tailings dam building material uses local materials, using tailings with a particle size of less than 20 mm, without the need to add traditional crushed stone aggregate.

5. The tailings damming material based on the curing agent modified tailings according to claim 4, characterized in that: The mechanical strength of the tailings pond gravity dam constructed with high-strength modified tailings dam materials includes but is not limited to reaching normal concrete strength C20, C25, C30 and above.

6. A dam-building method based on tailings dam-building materials modified by a curing agent as claimed in claim 2 or 3, characterized in that: (1) Carry out initial dam construction directly at the selected dam site and perform foundation clearing or dam foundation treatment in accordance with the specifications; (2) After treatment, earth-rock dam construction equipment is used on site to spread, layer, compact and roll the low-strength modified tailings dam material, where the layer thickness is 15~40cm, the compressive strength includes but is not limited to 0.25~2.00MPa, and the internal friction angle φ≥22°; (3) The dam body constructed with low-strength modified tailings dam material has mechanical properties equal to or higher than those of natural earth-rock dam body, and the dam body has anti-seepage performance that meets environmental protection requirements: K≤1.0×10 -5 ~1.0×10 -7 cm / s.

7. A dam-building method based on tailings dam-building materials modified by a curing agent as claimed in claim 2 or 3, characterized in that: (1) Clean the foundation or treat the dam foundation according to the specifications, and first construct a low dam with a natural earth-stone foundation at the selected dam site; (2) After a certain amount of tailings is blocked by a basic low dam, the tailings are mixed with a solidifying agent to obtain a low-strength modified tailings dam-building material, and the low-strength modified tailings dam-building material is used on the basic low dam to construct and raise the dam body; (3) Spread, layer, compact and roll the low-strength modified tailings dam material on site, where the layer thickness is 15~40cm, the compressive strength includes but is not limited to 0.25~2.00MPa, and the internal friction angle φ≥22°; (4) The final dam body has mechanical properties similar to those of a natural earth-rock dam body, and the dam body anti-seepage capacity K≤1.0×10 -5 ~1.0×10 -7 cm / s.

8. A dam-building method based on tailings dam-building materials modified by a curing agent as claimed in claim 7, characterized in that: In the step (1), the height H of the low dam is 5.0-10.0 m, but is not limited to this range, and the top width B of the low dam is ≥3 m.

9. A dam-building method based on tailings dam-building materials modified by a curing agent as claimed in claim 4 or 5, characterized in that: High-strength modified tailings dam-building materials are used to build gravity dams. The construction method of the dam is traditional concrete mixing, pouring and curing. The tailings are modified into high-strength modified tailings dam-building materials to build traditional concrete dams, mortar-masonry dams, buried stone concrete dams and interception dams in tailings ponds. The anti-seepage capacity of the dam body meets the requirements of national environmental protection standards.