A homogeneous self-insulating block made from gold tailings and its preparation method

Abstract

The present invention relates to a homogeneous self-insulating block made from gold tailings 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 in the prior art, resource waste and environmental pollution caused by direct discard. The present invention provides a homogeneous insulating block made from gold tailings, comprising gold tailings, cement, water, admixtures, foaming agents, and polystyrene foam particles. The above-mentioned homogeneous self-insulating block realizes the efficient recycling of gold tailings, avoids resource waste and environmental pollution, and the prepared homogeneous self-insulating block has excellent performance, meeting the national building standards GB / T 11969-2020 and GB / T 10294-2008, with a compressive strength (MPa) > 5.0, an average dry density (kg / m 3 ): 630-730, and a dry-state thermal conductivity (W / m·K) < 0.12, and can be widely applied to scenarios such as external wall insulation, cold storage insulation, and ground and roof insulation layers.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste resource treatment, and particularly relates to a homogeneous self-insulating block made of gold tailings as raw material and a preparation method thereof. Background Art

[0002] Gold tailings are waste or garbage generated after the flotation of gold ore, which is a kind of solid waste. They contain 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.

[0003] Taking the gold industry in Lingbao City as an example, the gold industry has always been the pillar and leader of the economic development of Lingbao City. However, with the continuous exploitation of gold mines and the continuous consumption of mineral resources, the gold ore, as a non-renewable resource, is getting less and less, while the gold tailings are getting more and more.

[0004] The currently known ways of gold tailings resource research mainly include the following: (1) Tailings re-election: Study the re-election properties of the available mineral components in many tailings. However, this method is not only not yet mature in technology, with 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, and even if they can be removed, it will lead to a significant increase in treatment costs.

[0005] In summary, in order to realize the resource utilization of gold tailings and thus avoid resource waste and environmental pollution, it is very necessary to develop an economically feasible method and approach for the recycling of gold tailings. Summary of the Invention

[0006] In view of the above analysis, the embodiments of the present invention aim to provide a homogeneous self-insulating block made of gold tailings as raw material and a preparation method thereof, so as to solve at least one of the problems such as the insufficient recycling of gold tailings in the prior art and the resource waste and environmental pollution caused by direct discard.

[0007] The present invention discloses a homogeneous insulating block made of gold tailings as raw material, and the homogeneous insulating block includes a gold tailings treatment product, cement, water, an admixture, a foaming agent, and polystyrene foam particles.

[0008] Specifically, the composition of the homogeneous insulating block is calculated by mass percentage as follows: 35-42% of the gold tailings treatment product, 38-45% of cement, 16-18% of water, 0.5-1.0% of the admixture, 0.25-0.5% of the foaming agent, and 0.8-1.2% of polystyrene foam particles.

[0009] Preferably, 38% of gold tailings treatment product, 43% of cement, 17% of water, 0.7% of admixture, 0.3% of foaming agent, and 1% of polystyrene foam particles.

[0010] Specifically, the gold tailings treatment product is solid particles of gold tailings passing through a 40-mesh sieve; the solid particles need to be washed in advance before feeding.

[0011] In actual implementation, if there are no large lumps and impurities such as stones in the solid powder of gold tailings, it can also be used directly as the gold tailings treatment product without treatment, but it will cause a decline in product performance and there is a risk that the performance does not meet the standards.

[0012] Specifically, the admixture is a mixture of an organic adhesive and a thickener.

[0013] Specifically, among them, the organic adhesive is one of acrylic emulsion or polyvinyl alcohol;

[0014] Among them, the thickener is one or several of carboxymethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium carboxymethyl cellulose, sodium alginate, casein, sodium polyacrylate, polyoxyethylene, and polyvinyl pyrrolidone.

[0015] The present invention also discloses a preparation method of the homogeneous thermal insulation block as described above, which specifically includes the following steps:

[0016] S1: Screen and separate the gold tailings, and retain the solid particles of the material passing through a 40-mesh sieve;

[0017] S2: Wash the solid particles of the material passing through a 40-mesh sieve to obtain the gold tailings treatment product;

[0018] S3: Weigh or measure various raw materials according to the preset formula and mix them to obtain a mixture;

[0019] S4: Carry out operations such as injection molding, peeling, demolding, cutting, and curing on the mixture to obtain the finished product of the homogeneous thermal insulation block.

[0020] Specifically, the specific operation of the washing step in step S2 is as follows: the solid particles of the gold tailings passing through a 40-mesh sieve need to be rinsed with an aqueous solution three to four times before feeding to remove the residual flotation agent adsorbed on the surface of the gold tailings and ensure the uniformity and stability of the product; the aqueous solution contains a flocculant.

[0021] Specifically, the flocculant is one of polyferric sulfate or ferric chloride.

[0022] Specifically, the feeding sequence in step S3 is as follows: First, inject water and admixture into the mixer in proportion and stir evenly, then add cement and the gold tailings treatment material and stir evenly, then inject the foaming agent into the mixer with a foaming machine and stir evenly, and finally add polystyrene foam particles into the mixer and stir evenly.

[0023] Specifically, the solid particles passing through a 40-mesh sieve in step S1 account for more than 94% of the total mass of the gold tailings.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] 1. The recycling of gold tailings resources is realized, avoiding resource waste and environmental pollution. The present invention screens the gold tailings. The solid particles with two particle sizes of less than 40 mesh and more than 40 mesh, among which the solid particles / powders with a particle size of more than 40 mesh (i.e., the undersize) account for more than 94% (mass fraction) of the total amount of gold tailings, and can be used to prepare the homogeneous self-insulating block described in the present invention. In actual implementation, the large-particle-size solid particles or other impurities can be used as construction coarse sand.

[0026] Gold tailings are solid wastes remaining after the ore is crushed and ground in the gold mining process and then the gold concentrate is collected by chemical flotation. They are listed as a kind of solid waste in the national solid waste catalog. However, due to the complex composition of gold tailings compared with conventional building materials, the morphologies of each component are not uniform, and the property stability of different batches of gold tailings is far less than that of conventional building materials. Therefore, how to adjust the formula and optimize the process to improve the inclusiveness of the 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. In order to improve the performance of the above-mentioned insulating block, the present invention adopts the innovative thinking of combining inorganic adhesives (cement) with organic adhesives (admixture components). Inorganic materials are non-toxic, non-flammable, cheap, high-temperature resistant, and have no solvent volatilization; organic materials have good softness, high strength, corrosion resistance, strong bonding force, and a wide use temperature range, so that the structural strength (mainly referring to the compressive strength) of the insulating block is significantly improved.

[0027] The present invention aims at the performance requirements (national standards) of the homogeneous self-insulating block and combines the characteristics of gold tailings itself, such as fine solid particles, containing a large amount of non-metallic minerals such as mica, feldspar, and quartz, etc. The heavy metal content of the above solid particles is lower than the relevant standards for building materials in the national standards, and can be used in occasions such as external wall insulation and cold storage insulation. And the above homogeneous self-insulating block has excellent performance and low price. The homogeneous self-insulating block produced with gold tailings as the main raw material meets the national building standards GB / T 11969-2020 and GB / T 10294-2008, with a compressive strength (MPa) > 5.0 and an average dry density (kg / m 3): 630 - 730, dry thermal conductivity (W / m·K) < 0.12.

[0028] The present invention realizes the resource utilization of gold tailings, enabling nearly 100% recycling and reuse of gold tailings, greatly reducing resource waste and avoiding environmental pollution. It should be emphasized that since the gold tailings in the national industrial solid waste list are used as raw materials to prepare homogeneous thermal insulation blocks in the present invention, it is extremely difficult for the relevant properties to exceed those of similar products prepared with high-quality materials, and it is also unnecessary in terms of science and economy. Therefore, through appropriate formulation design and optimization, combined with reasonable process parameters, overcoming the inherent defects of gold tailings as solid hazardous waste, enabling the product to meet the relevant national standards and turning waste into treasure for gold tailings is the most crucial technical breakthrough and technical effect of the present invention.

[0029] 2. The preparation method of the homogeneous self-thermal insulation block provided by the present invention has easily available raw materials, simple processes, mild process conditions, and low costs, being suitable for large-scale production and wide promotion; and the product quality is stable, having great market potential.

[0030] 3. On the premise of realizing the resource utilization of tailings, the homogeneous self-thermal insulation block provided by the present invention has significant economic benefits, strongly driving the local economic development.

[0031] Taking the actual operation data of a homogeneous self-thermal insulation block production line with a daily output of 200 cubic meters as an example:

[0032] The cost of taking out gold tailings from the tailings pond and transporting them to the production line (labor and transportation costs) is 40 yuan / ton, which is equivalent to the cost of the gold tailings raw materials. The homogeneous self-thermal insulation block production line with a daily output of 200 cubic meters is calculated based on 8 working hours per day, with a total of 12 employees. The total investment in this production line is 5 million yuan, including 4.5 million yuan in fixed asset investment and 3.5 million yuan in equipment investment. The daily power consumption does not exceed 300 kwh. According to the market price in December 2023, raw materials: ordinary 42.5 grade cement is 450 yuan / ton, gold tailings transportation cost is 40 yuan / ton, admixture is 15 yuan / kg, foaming agent is 8 yuan / kg, and polystyrene foam particles are 12 yuan / kg. Products: The price of ordinary sand is 150 yuan / ton, and the self-thermal insulation concrete block is 420 yuan / m 3 . Producing 200 cubic meters of homogeneous self-thermal insulation blocks per day requires 56 tons of ordinary 42.5 grade cement; 70 tons of 40-mesh gold tailings undersize; 280 kg of admixture; 440 kg of foaming agent; 1200 kg of polystyrene foam particles; at the same time, 4 tons / day of construction sand can be co-produced. Calculated based on 300 working days per year, 60,000 cubic meters of homogeneous self-thermal insulation blocks can be produced annually, consuming 22,000 tons of gold tailings, and co-producing 1200 tons of construction sand.

[0033] Annual sales revenue = Revenue from 60,000 cubic meters of homogeneous self-insulating blocks + Revenue from 1,200 tons of construction sand = 60,000 m 3 × 420 yuan / m 3 + 1,200 tons × 150 yuan / ton = 25.2 million yuan + 1.8 million yuan = 25.38 million yuan

[0034] Annual production cost = Raw material cost (56 tons of ordinary 42.5-grade cement × 450 yuan / ton + 74 tons of gold tailings × 40 yuan / ton + 280 kg of admixture × 15 yuan / kg + 440 kg of foaming agent × 8 yuan / kg + 1,200 kg of polystyrene foam particles × 12 yuan / kg) × 300 days + Engineering cost + Equipment depreciation + Equipment maintenance + Employee salary and welfare + Management fee = (2.52 + 0.296 + 0.42 + 0.352 + 1.44) million yuan × 300 days + 300 degrees / day × 0.86 yuan / degree × 300 days + 3.5 million yuan ÷ 10 years + 3.5 million yuan ÷ 10 years × 20% + 12 people × 200,000 yuan / person·year + 12 people × 200,000 yuan / person·year × 20% = 15.084 million yuan + 77,000 yuan + 350,000 yuan + 70,000 yuan + 2.4 million yuan + 480,000 yuan = 18.461 million yuan

[0035] Annual profit and tax revenue = Annual sales revenue – Annual production cost = 25.38 million yuan – 18.461 million yuan = 6.919 million yuan

[0036] Thus, it can be seen that gold tailings are equivalent to ore resources and "secondary minerals", while saving land resources, reducing air pollution caused by dust, avoiding potential hazards of soil erosion and debris flow, improving the ecological environment, creating employment opportunities, improving the economic environment, and most importantly, ensuring the continuous supply of mineral resources.

[0037] This process method for treating gold tailings has low energy consumption, low cost, zero emissions and full recovery, significant economic benefits, and good social and environmental benefits.

[0038] 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 specification, and some advantages can be made obvious from the specification or understood by implementing the present invention. The purpose and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the specification and the drawings. Brief Description of the Drawings

[0039] 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.

[0040] Figure 1 It is the process flow chart for the preparation of homogeneous self-insulating blocks

[0041] Figure 2 It is a physical photo of the homogeneous self-insulating block in Example 1;

[0042] Figure 3 It is a site photo of the stacked storage of the homogeneous self-insulating block in actual production. Detailed implementation manners

[0043] The preferred embodiments of the present invention will be specifically described below with reference to 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.

[0044] Gold tailings are solid wastes remaining after the ore is crushed and ground during gold mine mining and then the gold concentrate is collected through chemical flotation, and are listed as a kind of solid waste in the solid waste catalog of the country. 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 are polluted by the atmosphere; second, the extremely fine tailings sand particles are affected by the wind (and even sandstorms may be formed), 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, damage the soil, harm organisms, silt up rivers, and pollute the atmosphere. Therefore, gold tailings must be concentrated and piled up 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, and are similar in raw material composition to many building materials products.

[0045] 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.

[0046] Table 1 EDX analysis results of gold tailings (%)

[0047]

[0048]

[0049] It is feasible to use gold tailings as raw materials for producing thermal insulation blocks in terms of composition and structure. The difficulty lies in how to bring out the structural characteristics of granite, corundum, marble, sodium potassium feldspar, etc., which is the unique feature of this invention. For example, inorganic adhesives (cement) and organic adhesives are used to tightly connect SiO2, Al2O3, CaCO3, sodium potassium feldspar and other metal oxides in the gold tailings; thickeners can reduce the surface tension of water, thereby improving the wettability and dispersibility of cement, reducing the friction between particles, and increasing the fluidity of cement; by forming a lubricating film on the surface of cement particles, thickeners can increase the distance between cement particles, reduce the aggregation and precipitation between particles, and thus improve the uniformity and stability of the mixture / block; the above formula design and overall optimization are the key creations of this invention.

[0050] The invention discloses a homogeneous thermal insulation block made of gold tailings. The homogeneous thermal insulation block includes gold tailings treatment product, cement, water, admixture, foaming agent, and polystyrene foam particles.

[0051] Specifically, the composition of the homogeneous thermal insulation block is calculated by mass percentage as follows: gold tailings treatment product 35 - 42%, cement 38 - 45%, water 16 - 18%, admixture 0.5 - 1.0%, foaming agent 0.25 - 0.5%, and polystyrene foam particles 0.8 - 1.2%.

[0052] Preferably, the gold tailings treatment product is 38%, cement is 43%, water is 17%, admixture is 0.7%, foaming agent is 0.3%, and polystyrene foam particles are 1%.

[0053] Gold tailings: The main component of the homogeneous thermal insulation block, which can ensure its structural strength while realizing waste utilization. Experimental data shows that the addition amount of gold tailings / treatment product cannot exceed 42% at most, otherwise the product performance will not meet the relevant requirements of national standards (mainly referring to compressive strength). In fact, when the gold tailings / treatment product is greater than 38%, the product performance begins to decline.

[0054] Cement: Ordinary Portland cement is selected. Judging from the experimental data, the cement with a grade of 62.5# has a stronger effect than that of 52.5# cement, the latter is stronger than 42.5# cement, and the effect of 32.5# cement is the worst. However, considering the comprehensive factors of industrial cost and cost performance, the 42.5 grade cement is selected in this invention. Cement plays the role of an adhesive in the thermal insulation block, which can make each component better bond into a whole, and after the cement hardens, it can effectively improve the hardness, wear resistance and stability of the homogeneous thermal insulation block. Adding more cement will not have an obvious negative impact on the performance of the homogeneous thermal insulation block, but it will cause side effects such as a decrease in the solid waste recycling rate and an increase in cost. Therefore, the cement addition amount is preferably 38 - 45%.

[0055] Additives: The additives are a mixture of an organic adhesive and a thickener.

[0056] The organic adhesive is one of acrylic emulsion or PVA (polyvinyl alcohol). The function of the organic adhesive is to better bond each component into a whole. Compared with pure cement as an adhesive, adding an appropriate amount of organic adhesive helps to improve the wear resistance, plasticity and toughness of the homogeneous insulation block.

[0057] The thickener can reduce the surface tension of water, thereby improving the wettability and dispersibility of cement, reducing the friction between particles, and increasing the fluidity of cement. By adjusting the fluidity of cement, the cement thickener can form a dense particle structure in the concrete, reducing the number and width of cracks in the concrete or the ground hardening layer.

[0058] By forming a lubricating film on the surface of cement particles, the thickener can increase the distance between cement particles, reduce the aggregation and precipitation between particles, thereby improving the uniformity and stability of the mixture / block. The cement thickener can improve the anti-segregation property and water retention property of cement, prevent the segregation and bleeding of cement during construction, and improve the uniformity and density of the mixture / block.

[0059] Preferably, the addition ratio (volume ratio) of the organic adhesive to the thickener is 1:0.5 - 2, and the performance of the final product prepared with the above mixing ratio is relatively balanced.

[0060] Foaming agent: The active aluminum powder is selected in the present invention. The foaming agent can make the block light and soft, increase the porosity of the material, and improve the heat insulation and sound absorption properties, etc. However, too much addition will cause a decrease in the strength of the material. Through experimental tests, when the addition amount of the foaming agent is 0.25 - 0.5%, the performance of the self-insulation block is relatively balanced, with good heat insulation performance and the structural strength not being significantly affected.

[0061] Polystyrene foam particles: They play roles such as light weight, sound insulation, heat insulation and increasing strength. The addition amounts of the foaming agent and polystyrene particles should be appropriate. Too little will result in the product not meeting the standards, and too much will increase the cost.

[0062] Specifically, the gold tailings treatment product is the solid particles of the material passing through a 40-mesh gold tailings sieve; the solid particles need to be washed in advance before feeding. In actual implementation, the gold tailings solid powder can also be used directly as the gold tailings treatment product without treatment, but it will cause a certain degree of waste of resources and poor economy.

[0063] Specifically, the additives are a mixture of an organic adhesive and a thickener.

[0064] Specifically, among them, the organic adhesive is one of acrylic emulsion or polyvinyl alcohol;

[0065] Among them, the thickener is one or several of carboxymethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium carboxymethyl cellulose, sodium alginate, casein, sodium polyacrylate, polyoxyethylene, and polyvinylpyrrolidone.

[0066] The present invention also discloses a preparation method of the homogeneous heat-insulating block as described above, which specifically includes the following steps:

[0067] S1: Screen and separate the gold tailings, and retain the solid particles passing through a 40-mesh sieve;

[0068] S2: Wash the solid particles passing through a 40-mesh sieve to obtain the gold tailings treatment product;

[0069] S3: Weigh or measure various raw materials according to a preset formula and perform mixing to obtain a mixture;

[0070] S4: Perform operations such as injection molding, peeling, demolding, cutting, and curing on the mixture to obtain the finished homogeneous heat-insulating block.

[0071] Specifically, the specific operation of the washing link in step S2 is as follows: The solid particles of the gold tailings passing through a 40-mesh sieve need to be rinsed with an aqueous solution three to four times before feeding to remove the residual flotation agent adsorbed on the surface of the gold tailings, ensuring the uniformity and stability of the product; the aqueous solution contains a flocculant.

[0072] Specifically, the flocculant is one of polyferric sulfate or ferric chloride, and the addition amount of the flocculant in the aqueous solution is 0.01-0.05% (mass ratio).

[0073] Specifically, the feeding sequence in step S3 is as follows: First, inject water and additives into the mixer according to the ratio and stir evenly, then add cement and the gold tailings treatment product and stir evenly, then use a foaming machine to inject the foaming agent into the mixer and stir evenly, and finally add polystyrene foam particles to the mixer and stir evenly.

[0074] Adopting the above raw material addition sequence can enable the organic adhesive and thickener to fully contact and pre-react with the cement and the gold tailings treatment product, obtaining a mixture intermediate with uniform and balanced performance; then, by adding the foaming agent and polystyrene foam particles, the sound insulation, heat insulation and other properties of the mixture are further optimized.

[0075] Specifically, the solid particles passing through a 40-mesh sieve in step S1 account for more than 94% of the total mass of the gold tailings. If the solid powder of the gold tailings directly taken out from the gold tailings reservoir without pretreatment is used to replace the solid particles of the gold tailings passing through a 40-mesh sieve, 100% full recycling of the gold tailings can be independently realized without generating secondary pollution.

[0076] Specifically, the above homogeneous self-insulating block products comply with the national building standards GB / T 11969-2020 and GB / T 10294-2008: compressive strength (MPa) > 5.0, average dry density (kg / m 3 ): 630 - 730, dry-state thermal conductivity (W / m·K) < 0.12.

[0077] Example 1

[0078] The specific formula of the homogeneous self-insulating block used in this example is as follows:

[0079] 38% of 40-mesh gold tailings treatment product, 43% of 42.5-grade cement, 17% of water, 0.7% of admixture (acrylic acid and industrial-grade carboxymethyl cellulose, volume ratio 1:1, where industrial-grade carboxymethyl cellulose contains a small amount of sodium carboxymethyl cellulose), 0.3% of foaming agent (activated aluminum powder), 1% of polystyrene foam particles.

[0080] The preparation method is as follows:

[0081] S1: Screen and separate the gold tailings, and retain the solid particles passing through a 40-mesh sieve;

[0082] S2: Wash the solid particles passing through a 40-mesh sieve to obtain the gold tailings treatment product;

[0083] S3: Weigh or measure various raw materials according to the preset formula and mix them. First, inject water and admixture into the mixer in proportion and stir evenly, then add cement and the gold tailings treatment product and stir evenly. Then, use a foaming machine to inject the foaming agent into the mixer and stir evenly. Finally, add polystyrene foam particles to the mixer and stir evenly to obtain the mixed material;

[0084] S4: Process the mixed material through the processes of injection molding, peeling, demolding, cutting, and curing to obtain the finished homogeneous insulation block. The specific formula of the homogeneous self-insulating block used in this example is as follows:

[0085] The obtained finished homogeneous insulation block has a compressive strength (MPa) of 12.5, an average dry density (kg / m 3 ): 677, and a dry-state thermal conductivity (W / m·K) of 0.09; it complies with the national building standards GB / T 11969-2020 and GB / T 10294-2008.

[0086] Example 2

[0087] The specific formula of the homogeneous self-insulating block used in this example is as follows:

[0088] 41% of the 40-mesh gold tailings treatment material, 39% of the 62.5-grade cement, 18% of water, 0.8% of admixtures (PVA and industrial-grade propylene glycol alginate, volume ratio 1:0.5, where the industrial-grade propylene glycol alginate may contain a small amount of sodium alginate), 0.4% of foaming agent (activated aluminum powder), 0.8% of polystyrene foam particles.

[0089] The preparation method is as follows:

[0090] S1: Screen and separate the gold tailings, and retain the solid particles of the materials passing through a 40-mesh sieve;

[0091] S2: Wash the solid particles of the materials passing through a 40-mesh sieve to obtain the gold tailings treatment material;

[0092] S3: Weigh or measure various raw materials according to the preset formula and mix them. First, inject water and admixtures into the mixer according to the ratio and stir evenly, then add cement and the gold tailings treatment material and stir evenly. Then, use a foaming machine to inject the foaming agent into the mixer and stir evenly. Finally, add polystyrene foam particles to the mixer and stir evenly to obtain the mixed material;

[0093] S4: Carry out processes such as mold injection, peeling, demolding, cutting, and curing on the mixed material to obtain the finished product of the homogeneous thermal insulation block. The specific formula of the homogeneous self-thermal insulation block used in this embodiment is:

[0094] The compressive strength (MPa) of the obtained finished product of the homogeneous thermal insulation block is 9.5, the average dry density (kg / m 3 ): 691, and the dry thermal conductivity (W / m·K) is 0.07; it meets the national building standards GB / T 11969-2020 and GB / T 10294-2008. Among them, due to the slightly higher addition amount of the gold tailings treatment material and the slightly lower addition amount of cement, the compressive strength of the product has decreased. However, due to the relatively excellent performance of the 62.5-grade cement, the compressive strength still meets the standard requirements after the decrease.

[0095] Example 3

[0096] The specific formula of the homogeneous self-thermal insulation block used in this embodiment is:

[0097] 35% of the 40-mesh gold tailings treatment material, 44% of the 52.5-grade cement, 18% of water, 1.0% of admixtures (acrylic acid and industrial-grade methyl cellulose, volume ratio 1:1.5), 0.5% of foaming agent (activated aluminum powder), 0.8% of polystyrene foam particles.

[0098] The preparation method is as follows:

[0099] S1: Screen and separate the gold tailings, and retain the solid particles of the materials passing through a 40-mesh sieve;

[0100] S2: Wash the solid particles passing through a 40-mesh sieve to obtain the treated gold tailings.

[0101] S3: Weigh or measure various raw materials according to a preset formula and mix them. First, inject water and additives into a mixer in proportion and stir evenly, then add cement and the treated gold tailings and stir evenly. Next, use a foaming machine to inject the foaming agent into the mixer and stir evenly. Finally, add polystyrene foam particles to the mixer and stir evenly to obtain a mixture.

[0102] S4: Process the mixture through processes such as mold injection, peeling, demolding, cutting, and curing to obtain the finished homogeneous insulation block. The specific formula of the homogeneous self-insulating block used in this embodiment is as follows:

[0103] The compressive strength (MPa) of the obtained finished homogeneous insulation block is 15, the average dry density (kg / m 3 ) is 703, and the dry thermal conductivity (W / m·K) is 0.06, meeting the national building standards GB / T 11969-2020 and GB / T 10294-2008. Among them, due to the slightly lower addition amount of the treated gold tailings, the slightly higher addition amount of cement, and the relatively high addition amounts of additives, foaming agents, etc., the compressive strength and heat insulation performance of the product have been improved to a certain extent, but the utilization rate of gold tailings has decreased.

[0104] Example 4

[0105] The specific formula of the homogeneous self-insulating block used in this embodiment is as follows:

[0106] Unscreened gold tailings 38%, 42.5-grade cement 43%, water 17%, additives 0.7% (acrylic acid and industrial-grade polyoxyethylene, volume ratio 1:1), foaming agent (active aluminum powder) 0.3%, polystyrene foam particles 1%.

[0107] The preparation method is as follows:

[0108] S1: Weigh or measure various raw materials according to a preset formula and mix them. First, inject water and additives into a mixer in proportion and stir evenly, then add cement and the treated gold tailings and stir evenly. Next, use a foaming machine to inject the foaming agent into the mixer and stir evenly. Finally, add polystyrene foam particles to the mixer and stir evenly to obtain a mixture.

[0109] S2: Process the mixture through processes such as mold injection, peeling, demolding, cutting, and curing to obtain the finished homogeneous insulation block. The specific formula of the homogeneous self-insulating block used in this embodiment is as follows:

[0110] The compressive strength (MPa) of the obtained homogeneous thermal insulation block finished product is 10.3, the average dry density (kg / m3): 684, and the dry thermal conductivity (W / m·K) is 0.09; it meets the national building standards GB / T 11969-2020 and GB / T 10294-2008. In view of the relatively high relative mass of the solid powder directly taken from the gold tailings in this embodiment and the relatively few large-particle agglomerates and impurities, the performance of the final product changes little. However, if the performance of the gold tailings solid powder is poor, it may lead to non-compliance of the final product properties.

[0111] Comparative Example 1

[0112] The specific formula of the homogeneous self-thermal insulation block used in this embodiment is as follows:

[0113] 45% of 40-mesh gold tailings treatment product, 35% of 42.5-grade cement, 17% of water, 0.7% of admixture (acrylic acid and industrial-grade carboxymethyl cellulose, volume ratio 1:1), 0.3% of foaming agent (activated aluminum powder), 1% of polystyrene foam particles.

[0114] The preparation method is as follows:

[0115] S1: Screen and separate the gold tailings, and retain the solid particles passing through a 40-mesh sieve;

[0116] S2: Wash the solid particles passing through a 40-mesh sieve to obtain the gold tailings treatment product;

[0117] S3: Weigh or measure various raw materials according to the preset formula and mix them. First, inject water and admixture into the mixer according to the ratio and stir evenly, then add cement and the gold tailings treatment product and stir evenly, then use a foaming machine to inject the foaming agent into the mixer and stir evenly, and finally add polystyrene foam particles into the mixer and stir evenly to obtain the mixed material;

[0118] S4: Carry out operations such as mold injection, peeling, demolding, cutting, and curing on the mixed material to obtain the homogeneous thermal insulation block finished product. The specific formula of the homogeneous self-thermal insulation block used in this embodiment is as follows:

[0119] The compressive strength (MPa) of the obtained homogeneous thermal insulation block finished product is 3.8, the average dry density (kg / m3): 664, and the dry thermal conductivity (W / m·K) is 0.11; the compressive strength does not meet the national building standards GB / T 11969-2020 and GB / T 10294-2008.

[0120] Comparative Example 2

[0121] The specific formula of the homogeneous self-thermal insulation block used in this embodiment is as follows:

[0122] 38% of unscreened gold tailings, 43% of 32.5-grade cement, 17.7% of water, 0.3% of foaming agent (activated aluminum powder), and 1% of polystyrene foam particles.

[0123] The preparation method is as follows:

[0124] S1: Weigh or measure various raw materials according to the preset formula and mix them. First, inject water into the mixer according to the proportion and stir evenly, then add cement and gold tailings treatment and stir evenly. Then, use a foaming machine to inject the foaming agent into the mixer and stir evenly. Finally, add polystyrene foam particles to the mixer and stir evenly to obtain a mixture.

[0125] S2: Process the mixture through procedures such as embryo injection, peeling, demoulding, cutting, and curing to obtain the finished product of homogeneous thermal insulation blocks. The specific formula of the homogeneous self-thermal insulation blocks used in this embodiment is:

[0126] The compressive strength (MPa) of the obtained finished product of homogeneous thermal insulation blocks is 3.3, the average dry density (kg / m3) is 697, and the dry thermal conductivity (W / m·K) is 0.10; the compressive strength does not meet the national building standards GB / T 11969-2020 and GB / T 10294-2008.

[0127] Since the gold tailings in this comparative example were not screened, the uniformity and stability of the final product were poor. And due to the lack of addition of admixtures, the overall structure of the product was unstable, so the compressive strength decreased significantly.

[0128] The above embodiments give several possible implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Based on actual production experience, generally speaking, when the addition amount of gold tailings treatment increases, the addition amount of cement (the same grade) should also be increased accordingly, so as to obtain homogeneous thermal insulation blocks with relatively excellent performance.

[0129] It should be emphasized that as long as the addition amounts of gold tailings treatment and cement (the same grade) fall within the defined scope of the present invention, the obtained homogeneous thermal insulation blocks can meet the minimum requirements of the national standards, but may not necessarily obtain the best performance.

[0130] The above 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 thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A homogeneous thermal insulation block made of gold tailings, characterized in that: The homogeneous thermal insulation block comprises a gold tailings treatment product, cement, water, an admixture, a foaming agent, and polystyrene foam particles; The gold tailings treatment product is solid particles of gold tailings passing through a 40-mesh sieve; The gold tailings are gold mine tailings in Lingbao City. The gold tailings include one or more non-metallic minerals such as mica, feldspar, and quartz. The elemental content in the gold tailings is calculated by mass percentage as follows: The admixture is a mixture of an organic adhesive and a thickening agent; The addition volume ratio of the organic adhesive to the thickening agent is 1:0.5 - 2; Among them, the organic adhesive is one of acrylic emulsion or polyvinyl alcohol; Among them, the thickening agent is one or several of carboxymethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium carboxymethyl cellulose, sodium alginate, casein, sodium polyacrylate, polyoxyethylene, and polyvinylpyrrolidone; The composition of the homogeneous thermal insulation block is calculated by mass percentage as follows: 35 - 42% of the gold tailings treatment product, 38 - 45% of cement, 16 - 18% of water, 0.5 - 1.0% of the admixture, 0.25 - 0.5% of the foaming agent, and 0.8 - 1.2% of polystyrene foam particles; The homogeneous insulating block complies with the national building standards GB / T 11969-2020 and GB / T 10294-2008: compressive strength > 5.0 MPa, average dry density: 630 - 730 kg / m 3 , dry thermal conductivity < 0.12 W / m·K.

2. The homogeneous thermal insulation block according to claim 1, characterized in that: The solid particles need to be washed in advance before feeding.

3. A method for preparing the homogeneous heat-insulating building block according to claim 1 or 2, characterized in that, Specifically, it includes the following steps: S1: Screen and separate the gold tailings, and retain the solid particles of the material passing through a 40-mesh sieve; S2: Wash the solid particles of the material passing through a 40-mesh sieve to obtain the gold tailings treatment product; S3: Weigh or measure various raw materials according to a preset formula and mix them to obtain a mixture; S4: Carry out operations such as injection molding, peeling, demolding, cutting, and curing on the mixture to obtain the finished homogeneous thermal insulation block.

4. The preparation method according to claim 3, characterized in that: The specific operation of the washing step in S2 is as follows: The solid particles of the gold tailings passing through a 40-mesh sieve need to be rinsed with an aqueous solution three to four times before feeding to remove the residual flotation agent adsorbed on the surface of the gold tailings; the aqueous solution contains a flocculant.

5. The preparation method according to claim 4, characterized in that: The flocculant is one of polyferric sulfate or ferric chloride.

6. The preparation method according to claim 3, characterized in that: The feeding order in S3 is as follows: First, inject water and the admixture into the mixer according to the ratio and stir evenly, then add cement and the gold tailings treatment product and stir evenly, then use a foaming machine to inject the foaming agent into the mixer and stir evenly, and finally add polystyrene foam particles into the mixer and stir evenly.

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