A foamed concrete grouting material using gold tailings as raw material and its preparation method

Abstract

The present invention relates to a foamed concrete grouting material using gold tailings as raw materials and a preparation method thereof, belonging to the technical field of solid waste resource treatment, and solving at least one of the problems such as insufficient recycling of gold tailings and resource waste and environmental pollution caused by direct discard in the prior art. The present invention discloses a foamed concrete grouting material, which is composed of two parts: solid material and liquid material. Among them, the solid material contains gold tailings treatment product, cement, glass wool and foaming agent; the liquid material contains organic binder, thickener, water reducer, early strength agent and water. The above grouting material has excellent performance, meets the standard of ordinary grouting material JC / T986-2005, the strength is ≥30Mpa within 1 to 3 days after casting and forming, the vertical expansion rate is ≥0.02%, and it has no corrosion effect on steel bars. It can be widely used in non-load-bearing walls, thermal pipelines, heat insulation outer shells of heating pipelines, outer thermal insulation layers of industrial kilns and other occasions; and the production process is simple, and the economic and environmental benefits are remarkable.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste resource treatment, and particularly to a foamed concrete grouting material using gold tailings as raw materials and a preparation method thereof. Background Art

[0002] Gold tailings are wastes or garbage generated after the flotation of gold ores. They are a kind of solid waste containing heavy metals and toxic and harmful pollutants, which will flow into the downstream or seep into the ground with water, polluting rivers and underground water sources, thus causing great harm to the environment. Lingbao City is one of the four major gold bases in China. For every 1 ton of gold produced, nearly 100,000 tons of gold tailings will be generated. The annual gold output in Lingbao City is 800,000 taels, and the gold tailings are about 4 million tons per year. If they cannot be effectively utilized, it will cause huge waste of resources.

[0003] Currently known methods for the resource utilization research of gold tailings mainly include the following: (1) Tailings re-selection: Study the re-selection properties of the utilizable mineral components in many tailings. However, this method not only has immature technology, complex process operations, but also causes relatively serious environmental pollution. (2) Using tailings as soil improvers: Tailings often contain trace elements such as Zn, Cu, Mo, V, B, Fe, and P, which are essential elements for plant growth and development. However, how to remove harmful heavy metals such as lead, chromium, and mercury from tailings and waste residues has become a major problem. Even if they can be removed, it will lead to a significant increase in treatment costs.

[0004] In summary, in order to realize the resource utilization of gold tailings and thus avoid waste of resources and environmental pollution, it is very necessary to develop an economically feasible method and approach for the recycling and utilization of gold tailings. Summary of the Invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a foamed concrete grouting material using gold tailings as raw materials and a preparation method thereof, so as to solve at least one of the problems such as insufficient recycling and utilization of gold tailings in the prior art and resource waste and environmental pollution caused by direct discard.

[0006] The present invention discloses a foamed concrete grouting material, which is composed of two parts: solid materials and liquid materials. Among them,

[0007] The solid materials contain gold tailings treatment products, cement, glass wool, and foaming agents;

[0008] The liquid materials contain organic binders, thickeners, water reducers, early strength agents, and water.

[0009] Specifically, the specific composition of the solid material is as follows by mass percentage: 60% - 65% of the gold tailings treatment product, 25% - 35% of cement, 1.5% - 2.0% of glass wool, and 3.0% - 3.5% of foaming agent.

[0010] Specifically, the gold tailings treatment product is gold tailings solid particles with a particle diameter of 300 mesh; the solid particles should be dried and dehydrated before use.

[0011] Specifically, the specific composition of the liquid material is as follows by mass percentage: 1.0% - 2.0% of organic binder, 2.0% - 5.0% of thickener, 1.5% - 2.0% of water reducer, 2.5% - 5% of early strength agent, and the rest is water.

[0012] Specifically, the foamed concrete grouting material complies with the JC / T986 - 2005 standard, with a strength ≥ 30 Mpa and a vertical expansion rate ≥ 0.02% within 1 - 3 days after casting and no corrosion effect on steel bars.

[0013] The present invention also discloses a preparation method of the foamed concrete grouting material, which specifically includes the following steps:

[0014] S1: Adjust the gold tailings into pulp and perform screening to obtain the undersize solid powder or wet material with a particle size of 300 mesh;

[0015] S2: After filtering, washing, drying, and dehydrating the solid powder or wet material obtained in S1, obtain the gold tailings treatment product;

[0016] S3: Configure the solid material and liquid material according to the preset formula. The solid material is obtained by mixing and drying, and the liquid material is obtained by stirring and mixing to obtain the foamed concrete grouting material product.

[0017] Specifically, the mass concentration of the pulp in step S1 is 40 - 60%.

[0018] Specifically, in step S1, the screening process uses a sieve mesh or a vibrating probability sieve for screening and separation.

[0019] Specifically, the solid material obtained in step S3 needs to be packaged in a sealed manner to isolate air, and the packaging bag complies with the national standard GB / T 9774—2020; the liquid material needs to be packaged in barrels, and the packaging barrel complies with the national standard GB18191 - 2000.

[0020] The present invention also discloses an application of the foamed concrete grouting material. After mixing the solid material, liquid material, and water in a certain proportion, a filling machine is used for on-site filling and construction.

[0021] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:

[0022] 1. The recycling of gold tailings resources is realized, avoiding resource waste and environmental pollution. In the present invention, the gold tailings are screened to obtain solid particles with three particle sizes: 0 - 20 mesh, 20 - 300 mesh, and above 300 mesh. Among them, the solid particles / powder passing through the 300 - mesh sieve account for about 40% (mass fraction) of the total amount of gold tailings and can be used to prepare foamed concrete grouting materials. In actual implementation, the 0 - 20 - mesh solid particles can be used as coarse building sand, and the 20 - 300 - mesh solid particles can be used to prepare building materials such as artificial stone.

[0023] Gold tailings are solid wastes remaining after the ore is crushed, ground, and the gold concentrate is collected through chemical flotation during the gold mining process, and are listed as a kind of solid waste in the national solid waste catalog. There are generally three ways for gold tailings to pollute the environment: First, some harmful gases escape during the weathering process of the tailings and pollute the atmosphere; second, the extremely fine tailings sand particles are affected by the wind (and even form sandstorms), causing serious harm to the nearby environment; third, during the flood season, the tailings and rainwater flow into farmland and rivers, damaging the groundwater. The tailings pollute the land, damage the landscape, destroy the soil, harm organisms, silt up rivers, and pollute the atmosphere. Therefore, gold tailings must be piled up in a tailings pond centrally to eliminate the harm to the environment. Gold mine tailings contain various metals such as gold, silver, copper, lead, and zinc, as well as a large amount of non - metallic minerals such as mica, feldspar, and quartz, and are similar in raw material composition to many building materials products.

[0024] However, since the composition of gold tailings is more complex than that of conventional building materials raw materials, the morphology of each component is not uniform, and the property stability of different batches of gold tailings is far less than that of conventional building materials. Therefore, the key and creativity of the present invention lie in how to adjust the formula and optimize the process to improve the inclusiveness of the gold tailings raw materials as much as possible, overcome their inherent defects, and at the same time take into account economy and product performance.

[0025] The present invention adopts the AB solid - liquid double - material mode to improve the performance of concrete materials, improve the construction strength, increase the construction speed, reduce the transportation cost, and greatly increase the product sales distance; in accordance with the performance requirements (national standards) of foamed concrete grouting materials and combined with the characteristics of gold tailings themselves, the solid particles / powder passing through the 300 - mesh sieve are selected as the main material for the concrete grouting materials. The heavy metal content of the above - mentioned solid particles is lower than the relevant standards for building materials in the national standards and can be used in non - load - bearing walls, thermal pipelines, heat - supply pipeline insulation outer layers, industrial furnace outer insulation layers, and other occasions.

[0026] In order to improve the performance of the above grouting materials, the present invention adopts the innovative thinking of combining inorganic binders (cement) with organic binders. Inorganic materials are non-toxic, non-flammable, inexpensive, high-temperature resistant, and have no solvent volatilization; organic materials have good softness, high strength, corrosion resistance, strong adhesion, and a wide range of operating temperatures. The present invention not only takes into account the convenience of product transportation, seals and bags the solid inorganic materials, and transports the liquid organic materials in barrels, eliminating the problem of long-distance transportation of foam concrete materials (such as foam concrete blocks); but also due to the addition of liquid organic materials, the cold and tensile strength and stability of the foam concrete grouting materials are significantly enhanced; at the same time, it solves the technical problem of preparation on-site as needed.

[0027] The foam concrete grouting material produced from 300-mesh gold tailings solid particles screened, washed, and pressure-filtered from gold tailings fully meets or even exceeds the performance indicators specified in JC / T986-2005 standard. The strength is ≥30Mpa within 1 - 3 days of filling, the vertical expansion rate is ≥0.02%, and it has no rusting effect on steel bars.

[0028] The present invention realizes the resource utilization of gold tailings. For example, by combining other technologies to further recycle solid powders of different particle sizes, nearly 100% recycling of gold tailings can be achieved, greatly reducing resource waste and avoiding environmental pollution.

[0029] It is worth emphasizing that since the present invention uses gold tailings in the national industrial solid waste list as raw materials to prepare grouting concrete materials, it is extremely difficult for the relevant performance to exceed that of similar products prepared from high-quality materials, and it is also unnecessary from the perspectives of science and economy. Therefore, through appropriate formulation design and optimization, and combined with reasonable process parameters, overcoming the inherent defects of gold tailings as solid hazardous wastes, enabling the product to meet the relevant national standards and turning waste gold tailings into valuable resources is the most crucial technical breakthrough and technical effect of the present invention.

[0030] 2. The preparation method of the foam concrete grouting material provided by the present invention has easily available raw materials, simple processes, mild process conditions, and low costs, and is suitable for large-scale production and wide promotion; moreover, the product quality is stable and has great market potential.

[0031] 3. On the premise of realizing the resource utilization of tailings, the foam concrete grouting material provided by the present invention has remarkable economic benefits and strongly drives the local economic development.

[0032] In the present invention, taking the experimental / operation data of processing 10 tons per hour as an example:

[0033] The 1.2KW motor is used to pump the gold tailings from the tailings pond to the flow guide device by a thick slurry pump, and the power consumption per hour is 1.2 degrees. The power of the vibrating probability sieve motor is 1.5KW, and the power consumption per hour is 1.5 degrees.

[0034] The sedimentation rate of the oversize material retained on a 20-mesh sieve is very fast, and solid-liquid separation is easy without the need for filtration by a filter press. Additionally, the amount of solid particles in the oversize material retained on a 20-mesh sieve is too small (less than 0.5% by weight), so it can be air-dried and does not consume electricity. The sedimentation rate of the oversize material retained on a 300-mesh sieve is slower. In this experiment, a suction filtration method is used for filtration, with a motor power of 0.2 KW, and the filter cake is dried and dehydrated using a drum dryer. For the undersize material passing through a 300-mesh sieve, a pressure filtration method is used to remove most of the water, with a motor power of 3.5 KW, and the filter cake is dried and dehydrated using a drum dryer.

[0035] In the raw material pretreatment section, or when the gold tailings are first made into raw materials for building sand, artificial stone, and foam concrete grouting materials, the energy consumption of the entire production line is approximately 150 kWh / ton. In short, when taking out the gold tailings from the tailings pond and making them into raw materials for building sand, artificial stone, and foam concrete grouting materials, the total energy consumption in the entire pretreatment process is 150 kWh / ton, and the pretreatment cost is roughly between 130 yuan / ton and 160 yuan / ton.

[0036] According to our experimental data, the weight percentages of the oversize material retained on a 300-mesh sieve and the undersize material passing through a 300-mesh sieve screened from the gold tailings are approximately 6:4. That is, there are approximately 400 kg of materials per ton of gold tailings that can be used as solid materials (i.e., gold tailings treatment products) for producing foam concrete grouting materials. The price of grouting materials in the market in 2023 ranges from 750 yuan / ton to 1200 yuan / ton. Even when sold at the lowest price of 750 yuan / ton, the foam concrete grouting materials produced with gold tailings as the main raw material increase the value of the gold tailings to 750 yuan / ton. Even without calculating the value of downstream products prepared from solid particles of gold tailings with other particle sizes, the market value of the foam concrete grouting materials alone can cover the cost and achieve profitability, and the economic benefits are very obvious.

[0037] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can be made obvious from the description or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs represent the same components.

[0039] Figure 1 It is a process flow diagram for preparing foam concrete grouting materials. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings. The accompanying drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0041] Gold tailings are the solid waste remaining after the ore is crushed and ground during the gold mining process and then the gold concentrate is collected through chemical flotation. They are listed as a type of solid waste in the national solid waste catalog. There are generally three ways for gold tailings to pollute the environment: First, some harmful gases escape during the weathering process of the tailings and pollute the atmosphere; second, the extremely fine tailings sand particles are affected by the wind (and even form sandstorms), causing serious harm to the nearby environment; third, during the flood season, the tailings and rainwater flow into farmland and rivers, damaging the groundwater. Tailings pollute the land, damage the landscape, destroy the soil, harm organisms, silt up rivers, and pollute the atmosphere. Therefore, gold tailings must be piled up centrally in a tailings pond to eliminate the harm to the environment. Gold mine tailings contain various metals such as gold, silver, copper, lead, and zinc, as well as a large amount of non-metallic minerals such as mica, feldspar, and quartz, which are similar to the raw material components of many building materials products. However, due to the complex composition of gold tailings compared with conventional building materials raw materials, the morphology of each component is not uniform, and the property stability of different batches of gold tailings is far inferior to that of conventional building materials. Therefore, how to adjust the formula and optimize the process to improve the inclusiveness of gold tailings raw materials as much as possible, overcome its inherent defects, and at the same time take into account economy and product performance is the key and creativity of the present invention.

[0042] The gold tailings raw materials were analyzed using an energy dispersive X-ray spectrometer (abbreviated as EDX, Energy Dispersive X-Ray Spectroscopy), and the analysis data are shown in Table 1 below.

[0043] Table 1 EDX analysis results of gold tailings (%)

[0044]

[0045] The present invention discloses a foamed concrete grouting material, which is composed of two parts: solid material and liquid material. Among them,

[0046] The solid material contains the treated gold tailings, cement, glass wool, and foaming agent;

[0047] The liquid material contains organic binder, thickener, water reducer, early strength agent, and water.

[0048] The present invention adopts the AB solid-liquid double-material mode to improve the performance of the concrete material, improve the construction strength, increase the construction speed, reduce the transportation cost, greatly increase the product sales distance, and at the same time solve the actual problem of mixing on-site as needed for construction.

[0049] Specifically, the specific composition of the solid material is as follows by mass percentage: 60% - 65% of the gold tailings treatment product, 25% - 35% of cement, 1.5% - 2.0% of glass wool, and 3.0% - 3.5% of foaming agent.

[0050] Gold tailings treatment product: According to our experimental data analysis, it is found that when ensuring that all properties meet the national product standards, the maximum addition amount of the gold tailings treatment product in the solid material is 65%. Excessive addition will inevitably cause a significant decline in product performance. In addition, the mesh number of the gold tailings treatment product is also crucial. If the mesh number is too low, it will contain gold tailings particles with larger particle sizes, resulting in poor product stability; if the mesh number is too high, it will cause the powder to be too fine, and the strength of the foam concrete will decrease after pouring and solidification.

[0051] Cement: In the present invention, ordinary Portland cement is selected as the inorganic binder. From the experimental data, the cement with a grade of 62.5# has a stronger effect than the 52.5# cement, the latter is stronger than the 42.5# cement, and the 32.5# cement has the worst effect. However, considering the comprehensive factors of industrial cost and cost performance, the present invention preferably selects the 42.5-grade cement. The main function of cement is to harden the grouting material and be able to form a firm bond with the surrounding concrete structure. Too low an addition amount will lead to insufficient strength of the grouting material or concrete, but too high an addition amount will cause cement saturation, affecting the strength of the grouting material and concrete structure, and even causing concrete cracking. Through experimental tests, when the cement addition amount is 25% - 35%, the performance of the grouting material is better.

[0052] Glass wool: Concrete is a material with high strength, but due to its large brittleness, low tensile strength and toughness, especially when subjected to external impact or vibration, it is prone to cracking or fracture. And glass wool, as a fiber-reinforced material, can act as a reinforcing layer in concrete, increasing the tensile strength and toughness of concrete, thereby making the concrete more durable and reliable. Too high an addition amount of glass wool has no obvious improvement in the tensile strength and toughness of concrete, and will cause cost increase and environmental pollution. Through experimental tests, when the glass wool addition amount is 1.5% - 2.0%, the performance of the foam concrete after filling is better.

[0053] Foaming agent: The foaming agent can make the concrete light and soft, increase the porosity of the material, and improve properties such as heat insulation and sound absorption. However, too large an addition amount will cause a decrease in material strength. Through experimental tests, when the foaming agent addition amount is 3.0% - 3.5%, the performance of the foam concrete after filling is relatively balanced, with good heat insulation performance and the structural strength not being significantly affected. In the present invention, there are no special requirements for the type of foaming agent, and common concrete foaming agents on the market can meet the implementation requirements of the present invention.

[0054] Specifically, the specific composition of the liquid material is as follows by mass percentage: organic binder 1.0% - 2.0%, thickener 2.0% - 5.0%, water reducer 1.5% - 2.0%, early strength agent 2.5% - 5%, and the rest is water.

[0055] In the liquid material:

[0056] Organic binder: The organic binder is one of acrylic emulsion or PVA (polyvinyl alcohol). The role of the organic binder is to better bond each component into a whole. The organic binder helps to better bond the components between the solid material and the liquid material together, making it a firm whole, so that the structural strength of the concrete is higher. If the addition amount is too low, the bonding effect is not good, and if the addition amount is too high, it will cause waste of resources. Through experimental verification, when the addition amount of the organic binder is 1.0% - 2.0%, it is more appropriate.

[0057] Thickener: It can be one or more of carboxymethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium carboxymethyl cellulose, sodium alginate, casein, sodium polyacrylate, polyoxyethylene, polyvinylpyrrolidone, etc. The main function of the thickener is to change the physical properties of the concrete, increase its viscosity and consistency, so as to improve the fluidity and plasticity of the concrete. However, if the addition amount is too large, it will affect the strength of the concrete. Through experimental verification, when the addition amount of the thickener is 2.0% - 5.0%, it is more appropriate.

[0058] Water reducer: It can be one or more of lignosulfonates, polycyclic aromatic salts, water-soluble resin sulfonates. Most water reducers belong to anionic surfactants. The water reducer can play the following roles: (1) Increase strength: The water reducer can prevent the repulsive effect between cement particles, thereby increasing the binding force between cement particles. While increasing the water addition amount, the strength of the paste will also increase accordingly. (2) Improve fluidity: The water reducer can improve the fluidity of the paste, increase the volume fraction of the liquid phase, and thus enhance the castability of the cement / grouting slurry. (3) Improve stability: The water reducer can improve the deterioration phenomenon and make the paste more stable. Under the action of external forces such as vibration, the interaction between cement particles is reduced, making the paste more stable. However, if the addition amount is too high, it will cause segregation and bleeding of the concrete, resulting in the phenomenon of bottom grabbing and no cohesiveness. Through experimental verification, when the addition amount of the water reducer is 1.5% - 2.0%, it is more appropriate.

[0059] Early strength agent: It can be one of inorganic substances such as chloride salts, sulfate salts, nitrite salts, chromate salts, or one of organic substances such as triethanolamine, calcium formate, urea, etc. The main role of the early strength agent is to accelerate the hydration rate of cement and promote the development of the early strength of the concrete; it has both early strength function and certain water-reducing and strength-enhancing functions.

[0060] Water: As a solvent or carrier for liquid materials.

[0061] Synergistic effect: Based on the theoretical analysis design, a large number of experimental verifications and optimizations, and the characteristics of gold tailings itself, the present invention creatively designs a two-component formula of AB materials (solid materials and liquid materials). The components act synergistically. For example, the organic binder and the inorganic binder (such as cement) work together, and appropriate components are added to the liquid material to improve the performance of cement, thereby improving the performance of the cured material after on-site batching. It overcomes the problems of complex composition, insufficient structural strength, and non-uniform morphology of gold tailings. After on-site batching and perfusion, a foam concrete grouting material meeting the national standards can be obtained.

[0062] Specifically, the gold tailings treatment is solid particles of gold tailings with a particle diameter of 300 mesh; the solid particles should be dried and dehydrated before use.

[0063] Specifically, the foam concrete grouting material meets the JC / T986 - 2005 standard, with a strength ≥ 30Mpa and a vertical expansion rate ≥ 0.02% within 1 - 3 days after casting and forming, and has no rusting effect on steel bars.

[0064] The present invention also discloses a preparation method of the above-mentioned foam concrete grouting material, which specifically includes the following steps:

[0065] S1: Adjust the gold tailings into pulp and perform screening to obtain solid powder or wet material with a particle size of 300 mesh under the sieve;

[0066] S2: Filter, dry and dehydrate the solid powder obtained in S1 to obtain the gold tailings treatment;

[0067] S3: Configure the solid material and the liquid material according to a preset formula. The solid material is obtained by mixing and drying, and the liquid material is obtained by stirring and mixing to obtain the foam concrete grouting material product.

[0068] Specifically, the mass concentration of the pulp in step S1 is 40 - 60%, such as 40%, 45%, 50%, 55%, 60%. Exemplarily, in actual implementation, the tailings in the gold tailings pond can be pumped into pulp and transported to the production plant area.

[0069] Specifically, in step S1, the screening process uses a sieve or a vibrating probability sieve for screening and separation.

[0070] Specifically, the solid material obtained in step S3 needs to be packaged in a sealed manner to isolate air, and the packaging bag complies with the national standard GB / T 9774—2020; the liquid material needs to be packaged in drums, and the packaging drum complies with the national standard GB18191 - 2000.

[0071] Specifically, in step S2, the solid powder obtained by wet screening in step S1 needs to be filtered by a filter, and the filter cake needs to be dried and dehydrated by a drum dryer. Optionally, the filtered water can be uniformly concentrated in a sedimentation tank and recycled after complexing treatment to remove the sediment.

[0072] Specifically, the material passing through a 300-mesh sieve accounts for about 40% of the total mass of the solid powder.

[0073] Specifically, in step S3, the solid material is formed by mixing and drying gold tailings treatment material, cement, glass wool, and foaming agent in a drum dryer. The drying temperature is greater than 300 °C, and the water content is less than 0.05%.

[0074] The present invention also discloses an application of the above foam concrete grouting material. After mixing the solid material, liquid material, and water, a filling machine is used for on-site filling and construction. The specific proportions of the added materials can be selected according to construction requirements and the instruction manual.

[0075] Exemplarily, for the construction requirements of non-load-bearing walls, filling can be carried out at a (mass) ratio of 60% solid material, 10% liquid material, and 30% water.

[0076] Exemplarily, for the construction requirements of pavement grouting supported by a metal frame, filling can be carried out at a (mass) ratio of 65% solid material, 8% liquid material, and 27% water.

[0077] Through analysis and testing, there are no radioactive elements in the gold tailings, and the total content of toxic elements such as lead, mercury, arsenic, and cadmium does not exceed 0.01%. It can be used as a building material. The flotation reagents such as No. 2 oil, xanthate, and black medicine added to the tailings during flotation are all soluble in water, and only pure water is used as the medium in this process without adding any other chemical reagents. The liquid-phase water is recycled after complexing treatment. The entire process has no carbon consumption, no three wastes discharge, and 100% full recovery of the tailings. This method has small equipment investment, simple process, low cost, high added value, no secondary pollution, significant resource utilization effect, is easy to be disposed of on a large scale, and has good environmental and economic benefits.

[0078] Example 1

[0079] The specific formula of the foam concrete grouting material used in this example is as follows:

[0080] The specific composition of the solid material is, by mass percentage: 65% of the gold tailings treatment material passing through 300 meshes, 30% of 42.5-grade cement, 2.0% of glass wool, and 3.0% of foaming agent (commercially available concrete foaming agent).

[0081] The specific composition of the liquid material is as follows by mass percentage: organic binder (acrylic emulsion) 1.5%, thickener (industrial carboxymethyl cellulose, which contains a small amount of sodium carboxymethyl cellulose) 4.0%, water reducer (lignosulfonate) 2.0%, early strength agent (urea) 3.5%, and the rest is water.

[0082] Preparation process:

[0083] S1: Adjust the gold tailings into a pulp with a mass concentration of 40 - 60% (rough control is acceptable) and perform screening to obtain a solid powder of the undersize material with a particle size of 300 mesh.

[0084] S2: After filtering and drying and dehydrating the solid powder obtained in S1, obtain the gold tailings treatment product.

[0085] S3: Configure the solid material and the liquid material according to the preset formula. The solid material is obtained by mixing and drying, and the liquid material is obtained by stirring and mixing to obtain the foam concrete grouting material product.

[0086] Among them, the solid material is formed by mixing and drying the gold tailings treatment product, cement, glass wool, and foaming agent in a drum dryer. The drying temperature is 320°C, and the water content is less than 0.05%.

[0087] Pouring and performance testing:

[0088] For on-site construction, use the filling machine produced by Pingdingshan Sanhe Technology Co., Ltd. to add the solid material, liquid material, and water according to the ratio in the instruction manual. The material addition ratio (mass ratio) is 60:30:10 (for wall pouring).

[0089] The product strength grade, density grade, dry shrinkage value, and thermal conductivity comply with the "National Building Materials Industry Standard of the People's Republic of China".

[0090] The measured strength within 3 days of pouring is 37 MPa, the vertical expansion rate is 0.05%. No rust is observed at the contact surface between the steel bar and the concrete during the experimental period (3 months). Finally, it is measured that the key performance parameters of the foam concrete grouting material after solidification meet the JC / T986 - 2005 standard and pass the construction acceptance.

[0091] Example 2

[0092] The specific formula of the foam concrete grouting material used in this example is as follows:

[0093] The specific composition of the solid material is as follows by mass percentage: 300 - mesh gold tailings treatment product 62%, 62.5 - grade cement 33%, glass wool 1.8%, foaming agent (commercially available concrete foaming agent) 3.2%.

[0094] The specific composition of the liquid material is as follows by mass percentage: organic binder (PVA) 1.7%, thickening agent (industrial-grade propylene glycol alginate, containing a small amount of sodium alginate) 2.5%, water-reducing agent (polycyclic aromatic salt) 1.5%, early-strength agent (calcium chloride) 4.5%, and the rest is water.

[0095] Preparation process:

[0096] S1: Adjust the gold tailings into pulp and screen it to obtain the undersize solid powder with a particle size of 300 mesh.

[0097] S2: Filter and dry-dehydrate the solid powder obtained in S1 to obtain the treated gold tailings.

[0098] S3: Configure the solid material and the liquid material according to the preset formula. The solid material is prepared by mixing and drying, and the liquid material is prepared by stirring and mixing to obtain the foam concrete grouting material product.

[0099] Among them, the solid material is formed by mixing and drying the treated gold tailings, cement, glass wool, and foaming agent in a drum dryer. The drying temperature is 320 °C, and the water content is less than 0.05%.

[0100] Pouring and performance testing:

[0101] For on-site construction, use the filling machine produced by Pingdingshan Sanhe Technology Co., Ltd. to add the solid material, liquid material, and water according to the ratio in the instruction manual. The material addition ratio (mass ratio) is 60:30:10 (for wall pouring).

[0102] The product strength grade, density grade, dry shrinkage value, and thermal conductivity comply with the "National Building Materials Industry Standard of the People's Republic of China".

[0103] The measured strength within 3 days after pouring is 42 MPa, the vertical expansion rate is 0.08%, no rust is observed at the contact surface between the steel bar and the concrete during the experimental period (3 months), and finally, the key performance parameters of the foam concrete grouting material after solidification meet the JC / T986-2005 standard and pass the construction acceptance.

[0104] Finally, the key performance parameters of the foam concrete grouting material after solidification meet the JC / T986-2005 standard and pass the construction acceptance.

[0105] Example 3

[0106] The specific formula of the foam concrete grouting material used in this example is as follows:

[0107] The specific composition of the solid material is as follows by mass percentage: 60% of the treated gold tailings with a particle size of 300 mesh, 35% of 32.5-grade cement, 1.5% of glass wool, and 3.5% of foaming agent (commercially available concrete foaming agent).

[0108] The specific composition of the liquid material is as follows by mass percentage: organic binder (acrylic emulsion) 3.0%, thickening agent (industrial methyl cellulose) 5.0%, water reducing agent (lignosulfonate and water-soluble resin sulfonate, mixed at a ratio of 1:1) 2.0%, early strength agent (sodium nitrite) 4.5%, and the rest is water.

[0109] Preparation process:

[0110] S1: Adjust the gold tailings into a pulp and perform screening to obtain the undersize solid powder with a particle size of 300 mesh.

[0111] S2: Filter and dry-dehydrate the solid powder obtained in S1 to obtain the gold tailings treatment product.

[0112] S3: Configure the solid material and the liquid material according to the preset formula. The solid material is obtained by mixing and drying, and the liquid material is obtained by stirring and mixing to obtain the foam concrete grouting material product.

[0113] Among them, the solid material is formed by mixing and drying gold tailings treatment product, cement, glass wool and foaming agent in a drum dryer, the drying temperature is 320 °C, and the water content is less than 0.05%.

[0114] Pouring and performance testing:

[0115] For on-site construction, use the filling machine produced by Pingdingshan Sanhe Technology Co., Ltd. to add the solid material, liquid material and water according to the ratio in the instruction manual. The material addition ratio (mass ratio) is 60:30:10 (for wall pouring).

[0116] The product strength grade, density grade, dry shrinkage value and thermal conductivity comply with the "National Building Materials Industry Standard of the People's Republic of China".

[0117] The measured strength within 3 days after pouring is 35 MPa, the vertical expansion rate is 0.04%, no rust is observed at the contact surface between the steel bar and the concrete within the experimental period (3 months), and finally the key performance parameters of the foam concrete grouting material after solidification meet the JC / T986-2005 standard and pass the construction acceptance.

[0118] Finally, it is measured that the key performance parameters of the foam concrete grouting material after solidification meet the JC / T986-2005 standard and pass the construction acceptance.

[0119] Comparative Example 1

[0120] Use the gold tailings treatment product with a particle size of 200 mesh, and other steps and parameters are the same as those in Example 2.

[0121] During the on-site batching process, it was found that there were many uneven lumps in the grouting material and the fluidity was poor; the dispersion performance was not good during the pouring process, especially when passing through more complex steel bar structures, the filling effect was poor, and there were pouring defects visible to the naked eye.

[0122] Comparative Example 2

[0123] The specific formula of the foamed concrete grouting material used in this comparative example is:

[0124] The specific composition of the solid material is calculated by mass percentage as follows: 75% of 300-mesh gold tailings treatment material, 20% of No. 32.5 cement, 1.5% of glass wool, and 3.5% of a foaming agent (commercially available concrete foaming agent).

[0125] The specific composition of the liquid material is as follows by mass percentage: 3.0% organic binder (acrylic emulsion), 5.0% thickener (industrial grade methyl cellulose), 2.0% water reducer (lignin sulfonate and water-soluble resin sulfonate, mixed in a ratio of 1:1), 4.5% early strength agent (sodium nitrite), and the rest is water.

[0126] Preparation process:

[0127] S1: The gold tailings are adjusted into a slurry and sieved to obtain a solid powder of 300 mesh size;

[0128] S2: After filtering, drying and dehydrating the solid powder obtained in S1, a gold tailings treated product is obtained;

[0129] S3: solid material and liquid material are prepared according to a preset formula, the solid material is prepared by mixing and drying, and the liquid material is prepared by stirring and mixing, so as to obtain a foamed concrete grouting material product.

[0130] The solid material is formed by mixing and drying gold tailings treatment material, cement, glass wool and foaming agent in a drum dryer at a drying temperature of 320°C and a water content of less than 0.05%.

[0131] Infusion and performance testing:

[0132] During on-site construction, use a filling machine produced by Pingdingshan Sanhe Technology Co., Ltd. to add solid materials, liquid materials and water according to the proportions in the instructions. The material addition ratio (mass ratio) is 60:30:10 (wall pouring).

[0133] The actual strength measured within 3 days of filling is 18MPa, which does not meet the relevant standard requirements.

[0134] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A foam concrete grouting material, characterized in that: The foamed concrete grouting material consists of two parts: solid material and liquid material. Among them, the solid material contains gold tailings treatment product, cement, glass wool and foaming agent; the liquid material contains organic binder, thickener, water reducing agent, early strength agent and water; the specific composition of the solid material is by mass percentage: 60% - 65% of gold tailings treatment product, 25% - 35% of cement, 1.5% - 2.0% of glass wool, 3.0% - 3.5% of foaming agent; the gold tailings treatment product is solid particles of the undersize material of gold tailings with a particle diameter of 300 mesh; the content of each element in the gold tailings is by mass percentage: the specific composition of the liquid material is by mass percentage: 1.0% - 2.0% of organic binder, 2.0% - 5.0% of thickener, 1.5% - 2.0% of water reducing agent, 2.5% - 5% of early strength agent, and the rest is water; the organic binder is one of acrylic emulsion or polyvinyl alcohol; the foamed concrete grouting material meets the JC / T986 - 2005 standard, and the strength is ≥30Mpa within 1 - 3 days after casting and molding, the vertical expansion rate is ≥0.02%, and it has no rusting effect on steel bars.

2. The foamed concrete grouting material according to claim 1, wherein: The solid particles should be subjected to drying and dehydration treatment before use.

3. A method for preparing the foamed concrete grouting material according to claim 1 or 2, characterized in that, Specifically, it includes the following steps: S1: Adjust the gold tailings into pulp and screen it to obtain solid powder or wet material of the undersize material with a particle size of 300 mesh; S2: After filtering, washing, drying and dehydrating the solid powder or wet material obtained in S1, the gold tailings treatment product is obtained; S3: Configure the solid material and liquid material according to the preset formula. The solid material is prepared by mixing and drying, and the liquid material is prepared by stirring and mixing to obtain the foamed concrete grouting material product.

4. The preparation method according to claim 3, characterized in that: The mass concentration of the pulp in step S1 is 40 - 60%.

5. The preparation method according to claim 3, characterized in that: In step S1, the screening link is carried out by using a sieve or a vibrating probability sieve for screening and separation.

6. The preparation method according to claim 3, characterized in that: The solid material obtained in step S3 needs to be packaged in a sealed air - insulated manner, and the packaging bag complies with the national standard GB / T 9774—2020; the liquid material needs to be filled into barrels for packaging, and the packaging barrel complies with the national standard GB18191 - 2000.

7. Use of the foamed concrete grouting material according to claim 1 or 2, or the foamed concrete grouting material prepared by the preparation method according to any one of claims 3 to 6, characterized in that: After mixing the solid material, liquid material and water, a filling machine is used for on - site filling and construction.

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