Sub-nanometer material, preparation method and application thereof

Abstract

The application discloses a sub-nanometer material, a preparation method and application thereof, and relates to the technical field of gold tailings, and discloses a sub-nanometer material, a preparation method and application thereof. Gold tailings are used as raw materials, the gold tailings are subjected to microwave treatment and cold water washing to obtain pretreated materials, fine particle grade tailing powder is obtained through classification overflow, the fine particle grade tailing powder is subjected to ball milling treatment under the action of a grinding aid, and flotation and colloidal mill grinding are carried out, and the sub-nanometer material is obtained. The sub-nanometer material can be used for building material or coating processing, realizes the recycling of the gold tailings, and has a good popularization and application prospect.

Description

Technical Field

[0001] This invention relates to a sub-nanomaterial, specifically to a sub-nanomaterial, its preparation method, and its applications. It belongs to the field of gold tailings recycling technology. Background Technology

[0002] As living standards improve, the demand for gold continues to rise, leading to an increase in gold production. However, gold mines generally have low gold content, resulting in the generation of large amounts of gold tailings during production. The dumping of gold tailings not only wastes resources but also poses numerous health risks.

[0003] 1. The vast majority of existing gold tailings are disposed of by dumping, which occupies a large amount of land and destroys a large amount of agricultural and forestry land.

[0004] 2. Gold tailings contain extremely fine tailings dust, which is easily generated in windy weather; gold tailings also contain residual mineral processing reagents, which can easily seep into the ground and pollute groundwater and the surrounding environment.

[0005] 3. Gold tailings are prone to flow and collapse when stored, especially during the rainy season, which can easily cause subsidence, landslides, and other dangerous accidents.

[0006] Gold tailings mainly contain SiO2, along with certain amounts of CaO, Fe2O3, Al2O3, and MgO, and small amounts of precious metals (such as Au and Ag) and heavy metals (such as Cu, Pb, and Zn). Minerally, they are primarily composed of quartz, feldspar, mica, clay, and residual metallic minerals. Pollutants include cyanide, mercury, and various flotation reagents. Most gold tailings contain over 80% silicon and aluminum oxides, a composition similar to many industrial building materials.

[0007] Reusing gold tailings can not only solve the problems of gold tailings accumulation and environmental pollution at the source, but also turn waste into treasure, and has a very good prospect for promotion.

[0008] Patent CN113773014B discloses a gold tailings concrete and its preparation method. First, cement, slag powder, fly ash, river sand, fine stone, and crushed stone are mixed and stirred to obtain a solid mixture. Then, the remaining raw materials, except for gold tailings sand or hydrophobically modified gold tailings sand, are added to the solid mixture and stirred to obtain a concrete slurry. Finally, gold tailings sand or hydrophobically modified gold tailings sand is added to the concrete slurry and stirred to obtain concrete. This patented technology adds gold tailings sand directly or after hydrophobic modification. However, the sharp edges of the gold tailings sand increase the friction between gold tailings sand particles and between gold tailings sand particles and other solid particles in the concrete. Furthermore, the extremely low fineness modulus of gold tailings sand results in significant adhesion between particles, negatively impacting the flowability of the concrete. To address this issue, this patented technology combines gold tailings sand with river sand with smooth, rounded particle surfaces, controlling the amount of gold tailings sand. However, this also hinders the large-scale reuse of gold tailings.

[0009] Patent CN101769035B discloses a method for preparing autoclaved aerated concrete (AAC) bricks from laterite-type gold tailings. The method uses gold tailings powder, gold tailings aggregate, and lime (or carbide slag) as raw materials. The process involves raw material pretreatment, metering, batching, mixing, roller mill activation, pressing, and high-pressure steam curing to produce autoclaved aerated concrete (AAC) bricks. This patented technology uses sieves or mechanical crushing to separate the gold tailings into particles smaller than 8mm. However, similar to the aforementioned patented technology, this is merely used as a common filler and has no positive impact on the performance of the final product. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a sub-nano material, preparation method and application, which processes gold tailings into sub-nano sizes and can be used in building materials or coatings, realizing the reuse of gold tailings and has good prospects for promotion and application.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A method for preparing sub-nanomaterials involves first subjecting gold tailings to microwave treatment and cold water washing to obtain pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterials. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, the modified palygorskite powder is uniformly mixed with quartz glass microspheres and modified konjac glucomannan carbon microspheres to obtain the final product.

[0013] Preferably, the microwave treatment process conditions are: 800-1000W microwave irradiation for 8-10 minutes.

[0014] Preferred method of cold water washing: immediately pour the microwave-treated gold tailings into 3 to 4 times its weight of cold water at 5 to 10°C, let stand for 5 to 7 minutes, and then filter to obtain the pretreated material.

[0015] Preferably, the overflow is achieved by a hydrocyclone, the underflow is dewatered to obtain 60-200 mesh coarse tailings sand, and the overflow is thickened and filtered to obtain 200-600 mesh fine tailings powder.

[0016] More preferably, a thickener is added for thickening, and the amount of thickener is 0.2 to 0.5% of the mass of the overflow material. The thickener is obtained by mixing alum and polyacrylamide in equal mass.

[0017] Preferably, the specific method of ball milling is as follows: fine-grained tailings powder, grinding aid and water are added to the ball mill at a mass ratio of 1:0.5-0.6:0.2-0.3. Zirconia beads with diameters of 0.5 mm, 5 mm and 10 mm are used as grinding balls, the mass ratio of grinding balls of each diameter is 1:2:3, the ball-to-material ratio is 20-30:1, the ball milling speed is 300-500 r / min, and the ball milling time is 2-3 hours.

[0018] A further preferred method involves sieving and recovering the grinding balls after ball milling.

[0019] Preferably, the ball milling material obtained from ball milling is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine, and reagents are added for flotation. The flotation reagent is a mixture of the following components in parts by weight: 3-8 parts sodium silicate, 3-5 parts sodium sulfate, 5-8 parts melamine, and 8-10 parts rosin soap; the reagent dosage is 45-50 g / t, and the flotation time is 3-5 minutes. Preferably, the particle size of the sub-nanomaterial is 0.1-1 nm.

[0020] Preferably, the specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 100-200 mesh palygorskite powder is added to a 1-2 mol / L hydrochloric acid solution with 4-5 times its weight, and treated with ultrasonic vibration at 400-500W for 80-90 minutes at 80-85℃. The solid is then filtered, washed with water 2-3 times, and dried to obtain acid-treated palygorskite powder.

[0021] Preferably, in preparing pretreated palygorskite powder, the specific method of surface modification by weight is as follows: add 1 part of acid-treated palygorskite powder to 5-6 parts of water, stir and mix well, adjust the pH to 8-9 using 1-2 mol / L sodium hydroxide solution, add 0.8-1 part of dopamine hydrochloride and 0.1-0.2 parts of hydrogen peroxide, stir and mix well, ball mill, filter to obtain solid, and dry to obtain pretreated palygorskite powder.

[0022] More preferably, the ball mill uses 10mm diameter zirconia beads as grinding balls, the ball-to-material ratio is 30:1, the ball milling speed is 300-500 r / min, and the ball milling time is 20-30 minutes.

[0023] Preferably, the premixed liquid is prepared by the following method, based on parts by weight: 0.3 to 0.5 parts of sodium polyacrylate are added to 100 parts of water at 60 to 70°C, stirred and dispersed evenly, allowed to cool naturally to room temperature, and then 1 to 2 parts of corn starch are added and stirred evenly to obtain the premixed liquid.

[0024] Preferably, the specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 4 to 5 times its weight, ultrasonically oscillated at 500 to 600W for 50 to 60 minutes, the solid is filtered, dried, pulverized, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0025] Preferably, the quartz glass microspheres are prepared using quartz sand with a particle size of 200-300 mesh as raw material and a radio frequency plasma device.

[0026] More preferably, the quartz glass microspheres are prepared by the following method: First, argon gas at a rate of 30-40 L / min is introduced into the sheath gas composition as a protective gas, and argon gas at a rate of 15-20 L / min is introduced as the center gas in a radio frequency plasma device. Then, a high-frequency power supply is introduced to generate a plasma flame, and the power is continuously increased. Simultaneously, hydrogen gas from the sheath gas composition is introduced, ultimately reaching a hydrogen flow rate of 15-20 L / min, a power of 40 kW, and a pressure of 120-130 kPa, which remains stable. Quartz sand is introduced into the plasma flame of the plasma torch at a rate of 5-7 g / min and melted, transforming into spherical particles under the action of surface tension. These particles then continue to fall from the inner tube of a stainless steel sleeve located below the plasma torch and are rapidly cooled to obtain quartz glass microspheres.

[0027] Preferably, the modified konjac glucomannan carbon microspheres are obtained by the following preparation method, based on parts by weight: 0.8-1 parts of konjac glucomannan are added to 30-50 parts of water, stirred and mixed, and subjected to hydrothermal reaction at 180-200°C for 10-12 hours. After natural cooling to room temperature, the precipitate is collected by centrifugation and washed 3-5 times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres are added to 4-5 parts of a 3-5 mg / mL dopamine aqueous solution, aerated, stirred at room temperature for 10-12 hours, and the precipitate is collected by centrifugation and vacuum dried at 60-80°C for 12-24 hours to obtain the modified konjac glucomannan carbon microspheres.

[0028] Further preferably, the centrifugation process conditions are: centrifugation at 10000-15000 r / min for 20-30 minutes; the pH of the dopamine aqueous solution is adjusted to 8.5 using tris(hydroxymethyl)aminomethane buffer.

[0029] Preferably, the mass ratio of modified palygorskite powder, quartz glass microspheres, and modified konjac glucomannan carbon microspheres is 1:0.4-0.5:0.08-0.1.

[0030] Preferably, a flotation process consisting of one roughing, one scavenging, and five cleaning stages is adopted, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0031] Preferably, the process conditions for colloid milling are: colloid milling at 4000-5000 r / min for 1-2 hours.

[0032] A sub-nanomaterial is obtained by the aforementioned preparation method.

[0033] The aforementioned application of a sub-nanomaterial in the processing of building materials or coatings.

[0034] The beneficial effects of this invention are:

[0035] This invention uses gold tailings as raw material. First, the gold tailings are microwave-treated and washed with cold water to obtain a pretreated material. Then, with the aid of a grinding aid, the pretreated material is ball-milled to obtain a sub-nanomaterial. The sub-nanomaterial obtained by this invention can be used in building materials or coatings processing, realizing the reuse of gold tailings and showing good prospects for widespread application.

[0036] This invention involves microwave treatment and cold water washing of gold tailings before ball milling to induce tailings fracture, reducing the difficulty of subsequent ball milling and thus reducing the particle size of the product through ball milling.

[0037] During ball milling, a grinding aid is added. This grinding aid is prepared by first acid-treating and surface-modifying palygorskite powder to obtain pretreated palygorskite powder. Then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder. Finally, the modified palygorskite powder is uniformly mixed with quartz glass microspheres and modified konjac glucomannan carbon microspheres. In other words, the grinding aid of this invention consists of three parts: modified palygorskite powder, quartz glass microspheres, and modified konjac glucomannan carbon microspheres. This multi-particle-size grinding aid promotes material pulverization, and combined with subsequent colloid milling, reduces the product particle size to the sub-nanometer level.

[0038] Papyrrolidone powder, after acid treatment, has its pore size fully expanded, promoting the entry of components from the premix into the papyrrolidone powder and their release during ball milling, thus providing better grinding assistance. Modified konjac glucomannan carbon microspheres are obtained by modifying konjac glucomannan carbon microspheres with dopamine, and work synergistically with other grinding aid components to improve ball milling performance. Detailed Implementation

[0039] The present invention will be further described below with reference to embodiments. It should be noted that the following description is only for explaining the present invention and does not limit its content.

[0040] For ease of comparison, the gold tailings in the examples and comparative examples all came from the same batch of tailings from a gold mine in Laizhou City, Shandong Province.

[0041] Example 1:

[0042] A method for preparing sub-nanomaterials involves first subjecting gold tailings to microwave treatment and cold water washing to obtain pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterials. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, 10 kg of modified palygorskite powder is mixed evenly with 4 kg of quartz glass microspheres and 0.8 kg of modified konjac glucomannan carbon microspheres to obtain the final product.

[0043] The microwave treatment process conditions are: 800W microwave irradiation for 8 minutes.

[0044] The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into 3 times its weight of 5°C cold water, let it stand for 5 minutes, and then filter to obtain the pretreated material.

[0045] The overflow is graded using a hydrocyclone. The underflow is dewatered to obtain 60-200 mesh coarse-grained tailings sand, while the overflow is thickened and filtered to obtain 200-600 mesh fine-grained tailings powder. A thickener is added for thickening, with the amount of thickener being 0.2% of the overflow material mass. The thickener is a mixture of equal masses of alum and polyacrylamide.

[0046] The ball milling material obtained from the ball mill is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine. Reagents are added for flotation. The flotation reagents are a mixture of the following components: 3 kg sodium silicate, 3 kg sodium sulfate, 5 kg melamine, and 8 kg rosin soap. The reagent dosage is 45 g / t, and the flotation time is 3 minutes.

[0047] The specific method for ball milling is as follows: fine-grained tailings powder, grinding aid, and water are added to a ball mill at a mass ratio of 1:0.5:0.2. Zirconia beads with diameters of 0.5 mm, 5 mm, and 10 mm are used as grinding balls, with a mass ratio of 1:2:3 for each diameter and a ball-to-material ratio of 20:1. The ball milling speed is 300 r / min, and the milling time is 2 hours. After ball milling, the grinding balls are screened and recovered.

[0048] The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 100-mesh palygorskite powder is added to a 1 mol / L hydrochloric acid solution with 4 times its weight, and treated with ultrasonic vibration at 400W for 80 minutes at 80℃. The solid is then filtered, washed twice with water, and dried to obtain acid-treated palygorskite powder.

[0049] The specific method for surface modification in preparing pretreated palygorskite powder is as follows: 10 kg of acid-treated palygorskite powder is added to 50 kg of water, stirred and mixed, the pH is adjusted to 8 using 1 mol / L sodium hydroxide solution, 8 kg of dopamine hydrochloride and 1 kg of hydrogen peroxide are added, stirred and mixed, ball-milled, filtered to obtain solid, and dried to obtain pretreated palygorskite powder.

[0050] The ball mill used 10mm diameter zirconia beads as grinding balls, with a ball-to-material ratio of 30:1, a ball milling speed of 300r / min, and a ball milling time of 20 minutes.

[0051] The premixed liquid is prepared by the following method: 0.3 kg of sodium polyacrylate is added to 100 kg of water at 60°C, stirred and dispersed evenly, naturally cooled to room temperature, 1 kg of corn starch is added, and stirred evenly to obtain the liquid.

[0052] The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 4, ultrasonically oscillated at 500W for 50 minutes, the solid is filtered, dried, crushed, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0053] The quartz glass microspheres are prepared using quartz sand with a particle size of 200 mesh as raw material and a radio frequency plasma device.

[0054] The quartz glass microspheres were prepared by the following method: Argon gas at a rate of 30 L / min was first introduced into a radio frequency plasma device as a protective gas (sheath gas composition) and argon gas at a rate of 15 L / min was introduced as a center gas. Then, a high-frequency power supply was introduced to generate a plasma flame, and the power was continuously increased. Simultaneously, hydrogen gas from the sheath gas composition was introduced, eventually reaching a hydrogen flow rate of 15 L / min, a power of 40 kW, and a pressure of 120 kPa, which remained stable. Quartz sand was then introduced into the plasma flame of the plasma torch at a rate of 5 g / min to melt it. Under the action of surface tension, it transformed into spherical particles, which then continued to fall from the inner tube of a stainless steel sleeve located below the plasma torch and were rapidly cooled to obtain quartz glass microspheres.

[0055] The modified konjac glucomannan carbon microspheres were obtained by the following preparation method: First, 0.8 kg of konjac glucomannan was added to 30 kg of water, stirred and mixed, and hydrothermally reacted at 180°C for 10 hours. After naturally cooling to room temperature, the precipitate was collected by centrifugation and washed three times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres were added to 4 kg of 3 mg / mL dopamine aqueous solution, aerated, stirred at room temperature for 10 hours, and the precipitate was collected by centrifugation and vacuum dried at 60°C for 12 hours to obtain the modified konjac glucomannan carbon microspheres.

[0056] The centrifugation conditions were: 10000 r / min for 20 minutes; the pH of the dopamine aqueous solution was adjusted to 8.5 using tris(hydroxymethyl)aminomethane buffer.

[0057] The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0058] The process conditions for colloid milling are: colloid milling at 4000 r / min for 1 hour.

[0059] Example 2:

[0060] A method for preparing sub-nanomaterials involves first subjecting gold tailings to microwave treatment and cold water washing to obtain pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterials. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, 10 kg of modified palygorskite powder is mixed evenly with 5 kg of quartz glass microspheres and 1 kg of modified konjac glucomannan carbon microspheres to obtain the final product.

[0061] The microwave treatment process conditions are: 1000W microwave irradiation for 10 minutes.

[0062] The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into 4 times its weight of 10°C cold water, let it stand for 7 minutes, and then filter to obtain the pretreated material.

[0063] The overflow is graded using a hydrocyclone. The underflow is dewatered to obtain 60-200 mesh coarse-grained tailings sand, while the overflow is thickened and filtered to obtain 200-600 mesh fine-grained tailings powder. A thickener is added for thickening, with the amount of thickener being 0.5% of the overflow material mass. The thickener is a mixture of equal masses of alum and polyacrylamide.

[0064] The ball milling material obtained from the ball mill is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine. Reagents are added for flotation. The flotation reagents are made by mixing the following components: 8 kg of sodium silicate, 5 kg of sodium sulfate, 8 kg of melamine, and 10 kg of rosin soap. The reagent dosage is 50 g / t, and the flotation time is 5 minutes.

[0065] The specific method for ball milling is as follows: fine-grained tailings powder, grinding aid, and water are added to a ball mill at a mass ratio of 1:0.6:0.3. Zirconia beads with diameters of 0.5 mm, 5 mm, and 10 mm are used as grinding balls, with a mass ratio of 1:2:3 for each diameter and a ball-to-material ratio of 30:1. The ball mill speed is 500 r / min, and the milling time is 3 hours. After ball milling, the grinding balls are screened and recovered.

[0066] The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 200-mesh palygorskite powder is added to a 2 mol / L hydrochloric acid solution with 5 times its weight, and treated with ultrasonic oscillation at 85℃ for 90 minutes at 500W. The solid is then filtered, washed with water 3 times, and dried to obtain acid-treated palygorskite powder.

[0067] The specific method for surface modification in preparing pretreated palygorskite powder is as follows: 10 kg of acid-treated palygorskite powder is added to 60 kg of water, stirred and mixed, the pH is adjusted to 9 using 2 mol / L sodium hydroxide solution, 10 kg of dopamine hydrochloride and 2 kg of hydrogen peroxide are added, stirred and mixed, ball-milled, filtered to obtain solid, and dried to obtain pretreated palygorskite powder.

[0068] The ball mill used 10mm diameter zirconia beads as grinding balls, with a ball-to-material ratio of 30:1, a ball milling speed of 500r / min, and a ball milling time of 30 minutes.

[0069] The premixed liquid is prepared by the following method: 0.5 kg of sodium polyacrylate is added to 100 kg of water at 70°C, stirred and dispersed evenly, naturally cooled to room temperature, 2 kg of corn starch is added, and stirred evenly to obtain the liquid.

[0070] The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 5, ultrasonically oscillated at 600W for 60 minutes, the solid is filtered, dried, crushed, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0071] The quartz glass microspheres are prepared using 300-mesh quartz sand as raw material and a radio frequency plasma device.

[0072] The quartz glass microspheres were prepared by the following method: First, argon gas at a rate of 40 L / min was introduced into the sheath gas composition as a protective gas, and argon gas at a rate of 20 L / min was introduced as the center gas in a radio frequency plasma device. Then, a high-frequency power supply was introduced to generate a plasma flame, and the power was continuously increased. Simultaneously, hydrogen gas from the sheath gas composition was introduced, eventually reaching a hydrogen flow rate of 20 L / min, a power of 40 kW, and a pressure of 130 kPa, which remained stable. Quartz sand was then introduced into the plasma flame of the plasma torch at a rate of 7 g / min to melt it. Under the action of surface tension, it became spherical particles, which then continued to fall from the inner tube of a stainless steel sleeve located below the plasma torch and were rapidly cooled to obtain quartz glass microspheres.

[0073] The modified konjac glucomannan carbon microspheres were obtained by the following preparation method: 1 kg of konjac glucomannan was added to 50 kg of water, stirred and mixed, and subjected to hydrothermal reaction at 200°C for 12 hours. After natural cooling to room temperature, the precipitate was collected by centrifugation and washed 5 times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres were added to 5 kg of 5 mg / mL dopamine aqueous solution, aerated, stirred at room temperature for 12 hours, and the precipitate was collected by centrifugation and vacuum dried at 80°C for 24 hours to obtain the modified konjac glucomannan carbon microspheres.

[0074] The centrifugation process conditions were: 15000 r / min for 30 minutes; the pH of the dopamine aqueous solution was adjusted to 8.5 using tris(hydroxymethyl)aminomethane buffer.

[0075] The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0076] The process conditions for colloid milling are: colloid milling at 5000 r / min for 2 hours.

[0077] Example 3:

[0078] A method for preparing sub-nanomaterials involves first subjecting gold tailings to microwave treatment and cold water washing to obtain pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterials. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, 10 kg of modified palygorskite powder is mixed evenly with 4 kg of quartz glass microspheres and 1 kg of modified konjac glucomannan carbon microspheres to obtain the final product.

[0079] The microwave treatment process conditions are: 1000W microwave irradiation for 8 minutes.

[0080] The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into 3 times its weight of 10°C cold water, let it stand for 5 minutes, and then filter to obtain the pretreated material.

[0081] The overflow is graded using a hydrocyclone. The underflow is dewatered to obtain 60-200 mesh coarse-grained tailings sand, while the overflow is thickened and filtered to obtain 200-600 mesh fine-grained tailings powder. A thickener is added for thickening, with the amount of thickener being 0.2% of the overflow material mass. The thickener is a mixture of equal masses of alum and polyacrylamide.

[0082] The ball milling material obtained from the ball mill is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine. Reagents are added for flotation. The flotation reagents are a mixture of the following components: 8 kg of sodium silicate, 3 kg of sodium sulfate, 8 kg of melamine, and 8 kg of rosin soap. The reagent dosage is 50 g / t, and the flotation time is 3 minutes.

[0083] The specific method for ball milling is as follows: fine-grained tailings powder, grinding aid, and water are added to a ball mill at a mass ratio of 1:0.6:0.2. Zirconia beads with diameters of 0.5 mm, 5 mm, and 10 mm are used as grinding balls, with a mass ratio of 1:2:3 for each diameter and a ball-to-material ratio of 30:1. The ball milling speed is 300 r / min, and the milling time is 3 hours. After ball milling, the grinding balls are screened and recovered.

[0084] The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 100-mesh palygorskite powder is added to a 1 mol / L hydrochloric acid solution with 5 times its weight, and treated with ultrasonic vibration at 400W for 90 minutes at 85℃. The solid is then filtered, washed twice with water, and dried to obtain acid-treated palygorskite powder.

[0085] The specific method for surface modification in preparing pretreated palygorskite powder is as follows: 10 kg of acid-treated palygorskite powder is added to 60 kg of water, stirred and mixed, the pH is adjusted to 9 using 1 mol / L sodium hydroxide solution, 8 kg of dopamine hydrochloride and 2 kg of hydrogen peroxide are added, stirred and mixed, ball-milled, filtered to obtain solid, and dried to obtain pretreated palygorskite powder.

[0086] The ball mill used 10mm diameter zirconia beads as grinding balls, with a ball-to-material ratio of 30:1, a ball milling speed of 300r / min, and a ball milling time of 30 minutes.

[0087] The premixed liquid is prepared by the following method: 0.3 kg of sodium polyacrylate is added to 100 kg of water at 70°C, stirred and dispersed evenly, naturally cooled to room temperature, 1 kg of corn starch is added, and stirred evenly to obtain the liquid.

[0088] The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 5 times its weight, treated with ultrasonic vibration at 500W for 60 minutes, the solid is filtered, dried, crushed, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0089] The quartz glass microspheres are prepared using quartz sand with a particle size of 200 mesh as raw material and a radio frequency plasma device.

[0090] The quartz glass microspheres were prepared by the following method: First, argon gas at a rate of 40 L / min was introduced into the sheath gas composition as a protective gas, and argon gas at a rate of 15 L / min was introduced as the center gas in a radio frequency plasma device. Then, a high-frequency power supply was introduced to generate a plasma flame, and the power was continuously increased. Simultaneously, hydrogen gas from the sheath gas composition was introduced, eventually reaching a hydrogen flow rate of 20 L / min, a power of 40 kW, and a pressure of 120 kPa, which remained stable. Quartz sand was introduced into the plasma flame of the plasma torch at a rate of 7 g / min and melted. Under the action of surface tension, it became spherical particles, which then continued to fall from the inner tube of a stainless steel sleeve located below the plasma torch and were rapidly cooled to obtain quartz glass microspheres.

[0091] The modified konjac glucomannan carbon microspheres were obtained by the following preparation method: 0.8 kg of konjac glucomannan was added to 50 kg of water, stirred and mixed, and hydrothermally reacted at 180°C for 12 hours. After naturally cooling to room temperature, the precipitate was collected by centrifugation and washed three times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres were added to 5 kg of 3 mg / mL dopamine aqueous solution, aerated, stirred at room temperature for 12 hours, and the precipitate was collected by centrifugation and vacuum dried at 60°C for 24 hours to obtain the modified konjac glucomannan carbon microspheres.

[0092] The centrifugation process conditions were: 10000 r / min for 30 minutes; the pH of the dopamine aqueous solution was adjusted to 8.5 using tris(hydroxymethyl)aminomethane buffer.

[0093] The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0094] The process conditions for colloid milling are: colloid milling at 4000 r / min for 2 hours.

[0095] Example 4:

[0096] A method for preparing sub-nanomaterials involves first subjecting gold tailings to microwave treatment and cold water washing to obtain pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterials. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, 10 kg of modified palygorskite powder is mixed evenly with 4.5 kg of quartz glass microspheres and 0.9 kg of modified konjac glucomannan carbon microspheres to obtain the final product.

[0097] The microwave treatment process conditions are: 900W microwave irradiation for 9 minutes.

[0098] The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into 3.5 times its weight of 8°C cold water, let it stand for 6 minutes, and then filter to obtain the pretreated material.

[0099] The overflow is graded using a hydrocyclone. The underflow is dewatered to obtain 60-200 mesh coarse-grained tailings sand, while the overflow is thickened and filtered to obtain 200-600 mesh fine-grained tailings powder. A thickener is added for thickening, with the amount of thickener being 0.3% of the overflow material mass. The thickener is a mixture of equal masses of alum and polyacrylamide.

[0100] The ball milling material obtained from the ball mill is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine. Reagents are added for flotation. The flotation reagents are made by mixing the following components: 5 kg of sodium silicate, 4 kg of sodium sulfate, 6 kg of melamine, and 9 kg of rosin soap. The reagent dosage is 48 g / t, and the flotation time is 4 minutes.

[0101] The specific method for ball milling is as follows: fine-grained tailings powder, grinding aid, and water are added to a ball mill at a mass ratio of 1:0.55:0.25. Zirconia beads with diameters of 0.5mm, 5mm, and 10mm are used as grinding balls, with a mass ratio of 1:2:3 for each diameter and a ball-to-material ratio of 25:1. The ball milling speed is 400 r / min, and the milling time is 2.5 hours. After ball milling, the grinding balls are screened and recovered.

[0102] The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 200-mesh palygorskite powder is added to 4.5 times its weight of 2mol / L hydrochloric acid solution, and treated with ultrasonic vibration at 500W for 85 minutes at 83℃. The solid is then filtered, washed twice with water, and dried to obtain acid-treated palygorskite powder.

[0103] The specific method for surface modification in preparing pretreated palygorskite powder is as follows: 10 kg of acid-treated palygorskite powder is added to 55 kg of water, stirred and mixed, the pH is adjusted to 8 using 2 mol / L sodium hydroxide solution, 9 kg of dopamine hydrochloride and 1.5 kg of hydrogen peroxide are added, stirred and mixed, ball-milled, filtered to obtain solid, and dried to obtain pretreated palygorskite powder.

[0104] The ball mill used 10mm diameter zirconia beads as grinding balls, with a ball-to-material ratio of 30:1, a ball milling speed of 400r / min, and a ball milling time of 25 minutes.

[0105] The premixed liquid is prepared by the following method: 0.4 kg of sodium polyacrylate is added to 100 kg of water at 65°C, stirred and dispersed evenly, naturally cooled to room temperature, and then 1.5 kg of corn starch is added and stirred evenly.

[0106] The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 4.5 times its weight, treated with ultrasonic vibration at 600W for 55 minutes, filtered to obtain solid, dried, crushed, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0107] The quartz glass microspheres are prepared using 300-mesh quartz sand as raw material and a radio frequency plasma device.

[0108] The quartz glass microspheres were prepared by the following method: Argon gas at a rate of 35 L / min was first introduced into a radio frequency plasma device as a protective gas (sheath gas composition) and argon gas at a rate of 18 L / min was introduced as a center gas. Then, a high-frequency power supply was introduced to generate a plasma flame, and the power was continuously increased. Simultaneously, hydrogen gas from the sheath gas composition was introduced, eventually reaching a hydrogen flow rate of 18 L / min, a power of 40 kW, and a pressure of 130 kPa, which remained stable. Quartz sand was then introduced into the plasma flame of the plasma torch at a rate of 6 g / min to melt it. Under the action of surface tension, it became spherical particles, which then continued to fall from the inner tube of a stainless steel sleeve located below the plasma torch and were rapidly cooled to obtain quartz glass microspheres.

[0109] The modified konjac glucomannan carbon microspheres were obtained by the following preparation method: First, 0.9 kg of konjac glucomannan was added to 40 kg of water, stirred and mixed, and hydrothermally reacted at 190°C for 11 hours. After naturally cooling to room temperature, the precipitate was collected by centrifugation and washed four times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres were added to 4.5 kg of 4 mg / mL dopamine aqueous solution, aerated, stirred at room temperature for 11 hours, and the precipitate was collected by centrifugation and vacuum dried at 70°C for 20 hours to obtain the modified konjac glucomannan carbon microspheres.

[0110] The centrifugation conditions were: 12000 r / min for 25 minutes; the pH of the dopamine aqueous solution was adjusted to 8.5 using tris(hydroxymethyl)aminomethane buffer.

[0111] The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0112] The process conditions for colloid milling are: colloid milling at 5000 r / min for 1.5 hours.

[0113] Comparative Example

[0114] A method for preparing a powder material involves first subjecting gold tailings to microwave treatment and cold water washing to obtain a pretreated material. The pretreated material is then graded and overflowed to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterial. The grinding aid is prepared by: first, pretreated palygorskite powder is obtained by acid treatment and surface modification; then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder; finally, 10 kg of modified palygorskite powder is mixed uniformly with 4 kg of quartz glass microspheres to obtain the final product.

[0115] The microwave treatment process conditions are: 800W microwave irradiation for 8 minutes.

[0116] The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into 3 times its weight of 5°C cold water, let it stand for 5 minutes, and then filter to obtain the pretreated material.

[0117] The overflow is graded using a hydrocyclone. The underflow is dewatered to obtain 60-200 mesh coarse-grained tailings sand, while the overflow is thickened and filtered to obtain 200-600 mesh fine-grained tailings powder. A thickener is added for thickening, with the amount of thickener being 0.2% of the overflow material mass. The thickener is a mixture of equal masses of alum and polyacrylamide.

[0118] The ball milling material obtained from the ball mill is mixed with water to prepare a slurry with a mass concentration of 30%, which is then fed into a flotation machine. Reagents are added for flotation. The flotation reagents are a mixture of the following components: 3 kg sodium silicate, 3 kg sodium sulfate, 5 kg melamine, and 8 kg rosin soap. The reagent dosage is 45 g / t, and the flotation time is 3 minutes.

[0119] The specific method for ball milling is as follows: fine-grained tailings powder, grinding aid, and water are added to a ball mill at a mass ratio of 1:0.5:0.2. Zirconia beads with diameters of 0.5 mm, 5 mm, and 10 mm are used as grinding balls, with a mass ratio of 1:2:3 for each diameter and a ball-to-material ratio of 20:1. The ball milling speed is 300 r / min, and the milling time is 2 hours. After ball milling, the grinding balls are screened and recovered to obtain the powder material.

[0120] The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: 100-mesh palygorskite powder is added to a 1 mol / L hydrochloric acid solution with 4 times its weight, and treated with ultrasonic vibration at 400W for 80 minutes at 80℃. The solid is then filtered, washed twice with water, and dried to obtain acid-treated palygorskite powder.

[0121] The specific method for surface modification in preparing pretreated palygorskite powder is as follows: 10 kg of acid-treated palygorskite powder is added to 50 kg of water, stirred and mixed, the pH is adjusted to 8 using 1 mol / L sodium hydroxide solution, 8 kg of dopamine hydrochloride and 1 kg of hydrogen peroxide are added, stirred and mixed, ball-milled, filtered to obtain solid, and dried to obtain pretreated palygorskite powder.

[0122] The ball mill used 10mm diameter zirconia beads as grinding balls, with a ball-to-material ratio of 30:1, a ball milling speed of 300r / min, and a ball milling time of 20 minutes.

[0123] The premixed liquid is prepared by the following method: 0.3 kg of sodium polyacrylate is added to 100 kg of water at 60°C, stirred and dispersed evenly, naturally cooled to room temperature, 1 kg of corn starch is added, and stirred evenly to obtain the liquid.

[0124] The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 4, ultrasonically oscillated at 500W for 50 minutes, the solid is filtered, dried, crushed, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

[0125] The quartz glass microspheres are prepared using quartz sand with a particle size of 200 mesh as raw material and a radio frequency plasma device.

[0126] The quartz glass microspheres were prepared by the following method: Argon gas at a rate of 30 L / min was first introduced into a radio frequency plasma device as a protective gas (sheath gas composition) and argon gas at a rate of 15 L / min was introduced as a center gas. Then, a high-frequency power supply was introduced to generate a plasma flame, and the power was continuously increased. Simultaneously, hydrogen gas from the sheath gas composition was introduced, eventually reaching a hydrogen flow rate of 15 L / min, a power of 40 kW, and a pressure of 120 kPa, which remained stable. Quartz sand was then introduced into the plasma flame of the plasma torch at a rate of 5 g / min to melt it. Under the action of surface tension, it transformed into spherical particles, which then continued to fall from the inner tube of a stainless steel sleeve located below the plasma torch and were rapidly cooled to obtain quartz glass microspheres.

[0127] The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t of glacial acetic acid, 200 g / t of dodecylamine, and 100 g / t of sodium dodecyl sulfate are added.

[0128] The process conditions for colloid milling are: colloid milling at 4000 r / min for 1 hour.

[0129] Test case

[0130] The particle size of the sub-nano materials obtained in Examples 1 to 4 or the powder materials obtained in the comparative examples were tested using a nanoparticle size analyzer (Nicomp 380N3000). The results are shown in Table 1.

[0131] Table 1. Comparison of Product Particle Size

[0132] Average particle size (nm) Example 1 0.7 Example 2 0.7 Example 3 0.6 Example 4 0.5 Comparative Example 10.1

[0133] As shown in Table 1, the average particle size of the sub-nano materials obtained in Examples 1 to 4 is less than 1 nm, which is sub-nano scale.

[0134] The comparative example, omitting the modified konjac glucomannan carbon microspheres, yielded a powder material with a particle size greater than 1 nm. This indicates that the present invention improves the ball milling effect and reduces the product particle size through the synergistic effect of modified palygorskite powder, quartz glass microspheres, and modified konjac glucomannan carbon microspheres.

[0135] The sub-nanomaterials obtained in Examples 1-4 or the powder materials obtained in the comparative examples were used to prepare coatings. The following components by weight percentage were mixed evenly: 5% acrylate latex powder, 0.6% hydroxypropyl methylcellulose, and the remainder being sub-nanomaterials or powder materials. When using, an appropriate amount of water was added and thoroughly mixed before applying to walls or other surfaces to form a coating. The coatings were tested for hiding power (GB 1726-79(89), brush application method) and hardness (GB / T 6739-2022, Chinese pencil), and the results are shown in Table 2.

[0136] Table 2. Coating Performance Tests

[0137] <![CDATA[Hiding power (g / m 2 )]]> hardness Example 1 53 3H Example 2 52 3H Example 3 50 4H Example 4 48 4H Comparative Example 71 2H

[0138] As shown in Table 2, the coatings made from the sub-nano materials obtained in Examples 1 to 4 have excellent hiding power and high coating hardness, indicating that they have a very good application prospect in coating processing.

[0139] The coating made from the powder material obtained by omitting the modified konjac glucomannan carbon microspheres in the comparative example showed significantly worse hiding power and hardness, indicating that the particle size and specific composition of the product directly affect the performance of the coating.

[0140] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Based on the technical solutions of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

Claims

1. A method for preparing sub-nanomaterials, characterized in that, First, gold tailings are microwave-treated and cold-water washed to obtain pretreated material. The overflow from the pretreated material is then graded to obtain fine-grained tailings powder. Under the action of a grinding aid, the fine-grained tailings powder is ball-milled, flotated, and ground in a colloid mill to obtain the sub-nanomaterial. The grinding aid is prepared by the following method: First, palygorskite powder is acid-treated and surface-modified to obtain pretreated palygorskite powder. Then, the pretreated palygorskite powder is impregnated with a premixed solution containing sodium polyacrylate to obtain modified palygorskite powder. Finally, the modified palygorskite powder is mixed uniformly with quartz glass microspheres and modified konjac glucomannan carbon microspheres to obtain the final product. The modified konjac glucomannan carbon microspheres are obtained by the following preparation method: 0.8-1 parts of konjac glucomannan are added to 30-50 parts of water, stirred and mixed, and subjected to hydrothermal reaction at 180-200℃ for 10-12 hours. After natural cooling to room temperature, the precipitate is collected by centrifugation and washed 3-5 times with anhydrous ethanol to obtain konjac glucomannan carbon microspheres. Then, the konjac glucomannan carbon microspheres are added to 4-5 parts of 3-5 mg / mL dopamine aqueous solution, aeration is carried out, and the mixture is stirred at room temperature for 10-12 hours. The precipitate is collected by centrifugation and vacuum dried at 60-80℃ for 12-24 hours to obtain the modified konjac glucomannan carbon microspheres. The specific method of ball milling is as follows: fine-grained tailings powder, grinding aid and water are added to the ball mill at a mass ratio of 1:0.5-0.6:0.2-0.

3. Zirconia beads with diameters of 0.5 mm, 5 mm and 10 mm are used as grinding balls. The mass ratio of grinding balls of each diameter is 1:2:3, the ball-to-material ratio is 20-30:1, the ball milling speed is 300-500 r / min, and the ball milling time is 2-3 hours. The specific method for surface modification by weight is as follows: add 1 part of acid-treated palygorskite powder to 5-6 parts of water, stir and mix well, adjust the pH to 8-9 using 1-2 mol / L sodium hydroxide solution, add 0.8-1 part of dopamine hydrochloride and 0.1-0.2 parts of hydrogen peroxide, stir and mix well, ball mill, filter to obtain solid, and dry to obtain pretreated palygorskite powder; The mass ratio of modified palygorskite powder, quartz glass microspheres, and modified konjac glucomannan carbon microspheres is 1:0.4-0.5:0.08-0.

1.

2. The preparation method according to claim 1, characterized in that, The microwave treatment process conditions are: 800-1000W microwave irradiation for 5-8 minutes; The method of cold water washing is as follows: immediately pour the microwave-treated gold tailings into cold water at 5-10℃ with a weight of 3-4 times its weight, let it stand for 5-7 minutes, and then filter to obtain the pretreated material.

3. The preparation method according to claim 1, characterized in that, The specific method for acid treatment in preparing pretreated palygorskite powder is as follows: add 100-200 mesh palygorskite powder to a 1-2 mol / L hydrochloric acid solution with 4-5 times its weight, treat with ultrasonic vibration at 400-500W for 80-90 minutes at 80-85℃, filter to obtain solid, wash with water 2-3 times, and dry to obtain acid-treated palygorskite powder. The premixed liquid is prepared by the following method based on parts by weight: 0.3 to 0.5 parts of sodium polyacrylate are added to 100 parts of water at 60 to 70°C, stirred and dispersed evenly, allowed to cool naturally to room temperature, and then 1 to 2 parts of corn starch are added and stirred evenly.

4. The preparation method according to claim 1, characterized in that, The specific method of impregnation treatment is as follows: the pretreated palygorskite powder is completely immersed in a premixed liquid with a weight of 4 to 5 times its weight, ultrasonically oscillated at 500 to 600W for 50 to 60 minutes, the solid is filtered, dried, pulverized, and passed through a 100-mesh sieve to obtain modified palygorskite powder.

5. The preparation method according to claim 1, characterized in that, The quartz glass microspheres are prepared using quartz sand with a particle size of 200-300 mesh as raw material and a radio frequency plasma device.

6. The preparation method according to claim 1, characterized in that, The flotation process employs a roughing, scavenging, and cleaning process, with a flotation time of 20 minutes. During the flotation process, 2000 g / t glacial acetic acid, 200 g / t dodecylamine, and 100 g / t sodium dodecyl sulfate are added. The process conditions for colloid milling are: colloid milling at 4000-5000 r / min for 1-2 hours.

7. A sub-nanomaterial, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 6.

8. The application of the sub-nanomaterial of claim 7 in the processing of building materials or coatings.