High-content copper tailing rare earth grouting material and preparation method thereof

Abstract

The invention relates to the technical field of grouting materials, in particular to a high-content copper tailing rare earth grouting material and a preparation method thereof.The grouting material is prepared from, by weight, 70-90 parts of copper tailing-rare earth oxide clinker, 5-10 parts of fly ash, 1-5 parts of boron nitride fiber, 3-8 parts of clay auxiliaries, 0.05-0.15 part of expanding agent and 0.2-0.8 part of water reducing agent. The preparation method of the copper tailing-rare earth oxide clinker comprises the following steps: adding a proper amount of fluorine-containing rare earth mineral powder into water to obtain dispersion liquid containing the fluorine-containing rare earth mineral powder; and adding the dispersion liquid into copper tailing slag powder subjected to magnetic separation, carrying out heating and stirring reaction to obtain a copper tailing-rare earth dispersion liquid, carrying out solid-liquid separation, drying a copper tailing-rare earth precipitate, carrying out high-temperature roasting, cooling, and grinding and screening to obtain the copper tailing-rare earth oxide clinker. Double modification of the copper tailing slag powder and the fluorine-containing rare earth mineral powder is achieved, and the compactness and strength of the final grouting material can be effectively enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of grouting material preparation, and particularly relates to a copper tailings grouting material and a preparation method thereof. Background Art

[0002] Copper tailings, also known as copper tailings, are composed of fine powder sand particles left after the ore is crushed and selected. Except for a small amount of these tailings used as filling materials for old mines, the vast majority of the rest are stored in the form of filling depressions or damming. The piled copper tailings not only occupy a large amount of land, but also cover the original vegetation, destroying the ecosystem. Due to its special physical and chemical properties, the heavy metal content of tailings is particularly high, and it is difficult for plants to grow naturally on tailings. At the same time, tailings are blown by the wind and lost in rainwater, causing pollution to the living environment of residents in the surrounding areas. In the process of tailings management, vegetation reconstruction is the best way to manage tailings. In the process of vegetation restoration, the improvement of soil nutrients, the reduction of toxic substance concentrations, and the formation of tolerant plant varieties are all long-term processes. Therefore, the key to reclamation lies in the improvement of the substrate and the selection of tolerant species. The selection of species should emphasize the adaptability of species to the substrate and the improvement effect of species on the substrate. Among them, lawn grass plays an extremely important role in reducing environmental pollution and ecological protection.

[0003] Rare earth ores exist mainly in the form of minerals in the earth's crust. There are three main types of rare earth ores: As the basic constituent elements of minerals, rare earths are present in the mineral lattice in the form of ionic compounds, constituting an indispensable component of minerals. Such minerals are usually called rare earth minerals, such as monazite and bastnaesite. As impurity elements of minerals, they are dispersed in rock-forming minerals and rare metal minerals in the form of isomorphous substitution. Such minerals can be called minerals containing rare earth elements, such as apatite and fluorite, which are adsorbed on the surface or between particles of certain minerals in an ionic state. Such minerals are mainly various clay minerals and mica minerals. Rare earth elements in this state are easy to extract.

[0004] Grouting material is made of high-strength materials as aggregates, cement as a binder, and supplemented with high-fluidity, micro-expansion, anti-segregation and other materials. It can be used after adding a certain amount of water to the construction site and stirring evenly.

[0005] my country currently has a large stock of copper tailings, most of which are stored in the form of filling depressions or building dams. This storage method often causes heavy metal and acid pollution in the soil, especially for high-sulfur copper tailings, which are very harmful. How to reuse high-sulfur copper tailings has become a major problem at present. Rare earth ores are minerals rich in rare earth elements, and there are relatively few studies on their mining and utilization. At present, there are few reports on the combination of high-sulfur copper tailings and rare earth ores to prepare high-performance grouting materials. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned background technology, the present invention provides a high-doped copper tailings rare earth grouting material and a preparation method thereof, specifically: The first aspect of the present invention provides a high-dosage copper tailings rare earth grouting material, comprising the following raw materials in parts by weight: 70-90 parts of copper tailings-rare earth oxide clinker, 5-10 parts of fly ash, 1-5 parts of boron nitride fiber, 3-8 parts of clay additive, 0.05-0.15 parts of expansion agent and 0.2-0.8 parts of water reducer.

[0007] As a further illustration of the present invention, the method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding an appropriate amount of fluorine-containing rare earth mineral powder into water to obtain a dispersion containing the fluorine-containing rare earth mineral powder; S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder after magnetic separation, and then heating and stirring to react to obtain a copper tailings-rare earth dispersion; S3: performing solid-liquid separation on the copper tailings-rare earth dispersion to obtain a copper tailings-rare earth precipitate; S4: drying the copper tailings-rare earth precipitate, calcining it at high temperature, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker.

[0008] As a further illustration of the present invention, the fluorine-containing rare earth ore powder is bastnaesite powder, or, Mixed rare earth mineral powder of bastnaesite and monazite; The copper tailings slag powder includes the following chemical components by weight: SiO2 30-70 parts; Fe2O3 10-15 parts; Al2O3 8-12 parts; CaO 5-10 parts; S03 5-15 parts; The particle size of the fluorine-containing rare earth ore powder is 0.1-5um; the particle size of the copper tailings slag powder is 50-100um; The copper tailings-rare earth oxide clinker obtained by grinding and screening has a particle size of 10-20 um.

[0009] As a further illustration of the present invention, in step S1, the mass percentage of the fluorine-containing rare earth mineral powder in the dispersion containing the fluorine-containing rare earth mineral powder is 5-15%.

[0010] As a further illustration of the present invention, in step S2, the mass ratio of the dispersion of the copper tailings slag powder to the fluorine-containing rare earth ore powder is 1:1-3.

[0011] As a further illustration of the present invention, in step S2, the temperature of the heating and stirring reaction is 120-150° C., and the time is 1-3 hours.

[0012] As a further illustration of the present invention, the solid-liquid separation operation in step S3 adopts a filtration method or a centrifugal separation method.

[0013] As a further illustration of the present invention, in step S4, Drying conditions: vacuum drying at 60-80°C and vacuum degree of 93.3-98.6KPa; The high temperature roasting conditions are as follows: placing the dried copper tailings-rare earth precipitates in a rotary kiln, then heating to 200-300°C and keeping the temperature for 0.5-2h, then continuing to heat to 900°C-1100°C and keeping the temperature for 3-5h.

[0014] As a further illustration of the present invention, the clay additive is a mixture of bentonite and Guangxi white mud, and the mass ratio of the bentonite to the Guangxi white mud is 0.5-1:1; The expansion agent is one of polyether type, polyester type, and ether-ester mixed polyurethane; The water reducer is one of a sodium lignin sulfonate water reducer, a naphthalene-based water reducer and a polycarboxylic acid water reducer.

[0015] The second aspect of the present invention provides a method for preparing a high-dosage copper tailings rare earth grouting material, comprising the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 10-15:100.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention first uses the existing large amount of copper tailings slag powder as the main material of the grouting material, which can turn it into treasure and solve the problem of soil heavy metal pollution and acid pollution caused by direct landfill or stacking of the existing copper tailings slag powder; after rare earth compounds are added to the grouting material, the strength of the solidified slurry can be effectively improved, and a certain amount of rare earth oxides can be added to effectively reduce the thermal conductivity of the grouting material after solidification. Taking the above considerations into consideration, the present invention combines copper tailings slag powder with fluorine-containing rare earth ore powder, which can take advantage of the advantages of both and realize the improvement of traditional grouting materials.

[0017] The present invention realizes the dual modification of copper tailings slag powder and fluorine-containing rare earth ore powder, so that the final copper tailings-oxidized rare earth clinker contains stable metal oxides and rare earth oxides, which can exist in a stable state after being added into the grouting material, greatly reducing the corrosive problem of direct addition of copper tailings slag powder. At the same time, compared with rare earth ore powder, rare earth oxides are also obviously more advantageous in enhancing the density and strength of the material.

[0018] In addition, the present invention also adds some boron nitride fibers to the grouting material. The introduction of the boron nitride fibers can increase the hardness of the material on the one hand, and on the other hand, the boron nitride fibers are interspersed in the grouting material as a connecting skeleton, which can promote the bonding strength of the raw materials and further increase the bonding properties of the grouting material; finally, when the solidified grouting material encounters a high temperature environment, the boron nitride fibers are oxidized under high temperature conditions to form oxygen-containing defects, which will combine with the silicon dioxide in the copper tailings-rare earth oxide clinker to form a borosilicate glass phase, thereby forming a tight structure and increasing the strength of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention provides a method for preparing copper tailings-rare earth oxide clinker in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In view of the large amount of copper tailings currently in stock in my country, most of them are stored by filling depressions or building dams. This storage method often causes heavy metal and acid pollution in the soil, especially for high-sulfur copper tailings, which are very harmful. How to reuse high-sulfur copper tailings has become a major problem at present. Rare earth ores are minerals rich in rare earth elements, and there are relatively few studies on their mining and utilization. At present, the research on combining high-sulfur copper tailings with rare earth ores to prepare high-performance grouting materials is still a technical problem in the blank stage.

[0022] Based on the above technical problems, the present invention provides a high-dosage copper tailings rare earth grouting material, comprising the following raw materials in parts by weight: 70-90 parts of copper tailings-rare earth oxide clinker, 5-10 parts of fly ash, 1-5 parts of boron nitride fiber, 3-8 parts of clay additive, 0.05-0.15 parts of expansion agent and 0.2-0.8 parts of water reducer.

[0023] The above-mentioned copper tailings-rare earth oxide clinker can be, for example, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, etc.; the fly ash can be, for example, 5 parts, 7 parts, 8 parts, 10 parts, etc.; the boron nitride fiber can be, for example, 1 part, 2 parts, 5 parts; the clay additive can be, for example, 3 parts, 5 parts, 7 parts, 8 parts, etc.; the expansion agent can be, for example, 0.05 parts, 0.1 parts, 0.15 parts, etc.; the water reducer can be, for example, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, etc.

[0024] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: Add an appropriate amount of fluorine-containing rare earth mineral powder into water to obtain a dispersion containing fluorine-containing rare earth mineral powder.

[0025] The fluorine-containing rare earth ore powder is fluorocarbon cerium ore powder, or a mixed rare earth ore powder of fluorocarbon cerium ore and monazite.

[0026] The mass percentage of the fluorine-containing rare earth mineral powder in the dispersion containing the fluorine-containing rare earth mineral powder is 5-15%; the mass percentage of the fluorine-containing rare earth mineral powder can be, for example, 5%, 7%, 10%, 12%, 15%, etc.

[0027] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder after magnetic separation, and then heating and stirring to react to obtain a copper tailings-rare earth dispersion.

[0028] The copper tailings slag powder used here is high-sulfur copper tailings slag powder. Specifically, the copper tailings slag powder mainly includes the following chemical components in parts by weight: SiO2 30-70 parts; Fe2O3 10-15 parts; Al2O3 8-12 parts; CaO 5-10 parts; S03 5-15 parts; in addition, it also contains trace amounts of metal oxides or peroxides such as MgO, K2O, and TiO2.

[0029] When performing magnetic separation of copper tailings powder, the magnetic field strength used can be set to 1.5-2T.

[0030] The particle size of the fluorine-containing rare earth ore powder is 0.1-5um; the particle size of the copper tailings slag powder is 50-100um; the fluorine-containing rare earth ore powder is selected to be much smaller than the particle size of the copper tailings slag powder, so that the fluorine-containing rare earth ore powder can be fully dispersed in the copper tailings-rare earth dispersion liquid, and can quickly react with the acidic SO4 formed after the high-sulfur copper tailings are dissolved in water. 2- Combined with fluorine-containing rare earth ore powder and acidic SO4 2- The reaction causes the fluorine-containing rare earth ore powder to decompose and form rare earth sulfate.

[0031] The mass ratio of the copper tailings powder to the fluorine-containing rare earth ore powder dispersion is 1:1-3, and the amount ratio here can be, for example, 1:1, 1:2, 1:3, etc.

[0032] The temperature of the above-mentioned heating and stirring reaction is 120-150°C, and the time is 1-3 hours. The heating temperature is set to 120-150°C, which can accelerate the acid SO4 2- The reaction with the fluorine-containing rare earth ore powder will not cause the overflow of a large amount of strong acid gas due to excessively high temperature. Setting a longer reaction time can facilitate the full progress of the reaction.

[0033] S3: After solid-liquid separation of the copper tailings-rare earth dispersion, a copper tailings-rare earth precipitate is obtained.

[0034] The solid-liquid separation operation can be carried out by conventional solid-liquid separation methods such as filtration or centrifugation.

[0035] S4: drying the copper tailings-rare earth precipitate, calcining it at high temperature, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker.

[0036] The drying conditions are: vacuum drying at 60-80°C and a vacuum degree of 93.3-98.6 KPa.

[0037] The high temperature roasting conditions are as follows: placing the dried copper tailings-rare earth precipitates in a rotary kiln, then heating to 200-300°C and keeping the temperature for 0.5-2h, then continuing to heat to 900°C-1100°C and keeping the temperature for 3-5h.

[0038] Among them, the step-by-step heating conditions can ensure that the crystallization water and low-melting point compounds are fully removed at the low-temperature stage, providing conditions for high-temperature sintering. Then, after sufficient high-temperature sintering, the metal compounds in the copper tailings are converted into stable metal oxides, and the rare earth carbonate compounds and some of the remaining rare earth sulfate compounds are converted into stable rare earth oxides.

[0039] The particle size of the copper tailings-rare earth oxide clinker obtained by grinding and screening is 10-20um.

[0040] It should also be noted that the clay additive in the present invention is a mixture of bentonite and Guangxi white mud, and the mass ratio of bentonite to Guangxi white mud is 0.5-1:1, and the mass ratio can be, for example, 0.5:1, 0.7:1, 1:1, etc.

[0041] The expansion agent in the present invention is one of polyether type, polyester type, and ether-ester mixed polyurethane; The water reducer in the present invention is one of a sodium lignin sulfonate water reducer, a naphthalene series water reducer and a polycarboxylic acid water reducer.

[0042] In summary, the design concept of the high-doped copper tailings rare earth grouting material of the present invention is: The present invention first uses the existing large amount of copper tailings slag powder as the main material of the grouting material, which can turn it into treasure and solve the problem of heavy metal pollution and acid pollution in the soil caused by direct landfill or stacking of the existing copper tailings slag powder; and rare earth elements, due to their special atomic structure and interface properties, can effectively improve the grain boundary energy of the grouting material after rare earth compounds are added to the grouting material, so that the grouting wet material formed after the grouting dry powder is stirred with water can play a role in refining the grains, so that the solidified grouting material is more compact in the microscopic view, and the strength of the solidified slurry can be significantly improved in the macroscopic view. In addition, since rare earth oxides have extremely low thermal conductivity and are often used as raw materials for thermal barrier coatings, the raw materials finally added to the grouting material of the present invention contain a certain amount of rare earth oxides, so the thermal conductivity of the solidified grouting material can also be effectively reduced. Taking the above considerations into consideration, combining copper tailings slag powder with fluorine-containing rare earth ore powder can take advantage of the advantages of both and achieve improvements on traditional grouting materials.

[0043] In the process of combining copper tailings powder and fluorine-containing rare earth ore powder to prepare grouting material, if the two are directly added into the grouting material dry powder and used directly as raw materials, it is difficult to exert the synergistic effect of the two, and there will be problems such as easy corrosion of the grouting material and the strength needs to be further improved; therefore, before adding the two into the dry powder, corresponding modification treatment is carried out. First, the high-sulfur copper tailings powder contains a large amount of SO3 and trace sulfides, so it will form acidic sulfate ions and some S after dissolving in water. 2- After the fluorine-containing rare earth ore powder is dissolved in water as fine particles and then the high-sulfur copper tailings slag powder with larger particles is added, the fluorine-containing rare earth ore powder can be quickly integrated into the gaps of the high-sulfur copper tailings slag powder, accelerating its contact with sulfate ions. Under acidic conditions, it can be decomposed into some rare earth sulfates. Due to the presence of some carbonates formed after the high-sulfur copper tailings slag powder is dissolved in water, some rare earth sulfates will be converted into rare earth carbonate precipitation. Finally, after a high-temperature roasting stage, the metal compounds in the copper tailings are converted into stable metal oxides, and the rare earth carbonate compounds and some of the remaining rare earth sulfate compounds are converted into stable rare earth oxides. The above process realizes the dual modification of copper tailings slag powder and fluorine-containing rare earth ore powder, so that the final copper tailings-oxidized rare earth clinker contains stable metal oxides and rare earth oxides, which can exist in a stable state after being added into the grouting material, greatly reducing the corrosive problem of direct addition of copper tailings slag powder. At the same time, compared with rare earth ore powder, rare earth oxides are also obviously more advantageous in enhancing the density and strength of materials.

[0044] In addition, the present invention also adds some boron nitride fibers to the grouting material. The introduction of the boron nitride fibers can increase the hardness of the material on the one hand, and on the other hand, the boron nitride fibers are interspersed in the grouting material as a connecting skeleton, which can promote the bonding strength of the raw materials and further increase the bonding properties of the grouting material; finally, when the solidified grouting material encounters a high temperature environment, the boron nitride fibers are oxidized under high temperature conditions to form oxygen-containing defects, which will combine with the silicon dioxide in the copper tailings-rare earth oxide clinker to form a borosilicate glass phase, thereby forming a tight structure and increasing the strength of the material.

[0045] The second aspect of the present invention provides a method for preparing a high-dosage copper tailings rare earth grouting material, comprising the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 10-15:100.

[0046] The following is explained in conjunction with specific embodiments: The copper tailings slag powder used in the following embodiments and comparative examples are all high-sulfur copper tailings slag powder. Specifically, the weight percentages of the main chemical components measured in the copper tailings slag powder are: SiO2 49.35%; Fe2O3 11.25%; Al2O3 9.26%; CaO 8.22%; S03 11.22%; MgO 2.04%; K2O 1.02%; TiO2 2.13%, etc.

[0047] The fluorocarbon cerium ore used in the following examples and comparative examples was purchased from rare earth concentrate in Baotou, Inner Mongolia, and the ReO content of the concentrate was 68.23%. Example 1

[0048] A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 70 parts of copper tailings-rare earth oxide clinker, 5 parts of fly ash, 1 part of boron nitride fiber, 3 parts of bentonite, 4 parts of Guangxi white mud, 0.05 parts of polyether polyurethane expansion agent, and 0.2 parts of lignin sulfonate sodium salt water reducer.

[0049] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding fluorocarbon cerium ore powder with a particle size of 0.1 um into water to obtain a dispersion containing fluorine-containing rare earth ore powder, wherein the mass percentage of the fluorine-containing rare earth ore powder in the dispersion is 5%.

[0050] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder with a particle size of 50-70um after magnetic separation, wherein the mass ratio of the copper tailings slag powder to the dispersion of the fluorine-containing rare earth ore powder is 1:1; then heating and stirring at a temperature of 120°C for 1 hour to fully stir and react the two to obtain a copper tailings-rare earth dispersion.

[0051] S3: separating the copper tailings-rare earth dispersion into solid and liquid by centrifugal separation to obtain a copper tailings-rare earth precipitate.

[0052] S4: vacuum drying the copper tailings-rare earth precipitate at 60°C and a vacuum degree of 93.3 KPa; then placing the dried copper tailings-rare earth precipitate in a rotary kiln, heating it to 200°C and keeping it warm for 0.5h, then continuing to heat it to 900°C and keeping it warm for 3h, performing high-temperature roasting, and after cooling, grinding and screening to obtain copper tailings-rare earth oxide clinker with a particle size of 10um.

[0053] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 10:100. Example 2

[0054] A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 78 parts of copper tailings-rare earth oxide clinker, 7 parts of fly ash, 3 parts of boron nitride fiber, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.1 parts of polyester polyurethane expansion agent and 0.4 parts of naphthalene series water reducer.

[0055] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding fluorocarbon cerium ore powder with a particle size of 2 μm into water to obtain a dispersion containing fluorine-containing rare earth ore powder, wherein the mass percentage of the fluorine-containing rare earth ore powder in the dispersion is 10%.

[0056] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder with a particle size of 70-80um after magnetic separation, the mass ratio of the copper tailings slag powder to the dispersion of the fluorine-containing rare earth ore powder being 1:2; then heating and stirring at a temperature of 130°C for 2 hours to fully stir and react the two to obtain a copper tailings-rare earth dispersion.

[0057] S3: The copper tailings-rare earth dispersion is subjected to solid-liquid separation by centrifugal separation to obtain a copper tailings-rare earth precipitate.

[0058] S4: vacuum drying the copper tailings-rare earth precipitate at 70°C and a vacuum degree of 95.6 KPa; then placing the dried copper tailings-rare earth precipitate in a rotary kiln, heating it to 230°C and keeping it for 1 hour, then continuing to heat it to 1000°C and keeping it for 4 hours, high-temperature roasting, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker with a particle size of 20 um.

[0059] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 12:100. Example 3

[0060] A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 84 parts of copper tailings-rare earth oxide clinker, 8 parts of fly ash, 4 parts of boron nitride fiber, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.1 parts of polyether polyurethane expansion agent and 0.6 parts of naphthalene series water reducer.

[0061] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding fluorocarbon cerium ore powder with a particle size of 3 μm into water to obtain a dispersion containing fluorine-containing rare earth ore powder, wherein the mass percentage of the fluorine-containing rare earth ore powder in the dispersion is 12%.

[0062] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder with a particle size of 70-90um after magnetic separation, the mass ratio of the copper tailings slag powder to the dispersion of the fluorine-containing rare earth ore powder being 1:2; then heating and stirring at a temperature of 140°C for 2 hours to fully stir and react the two to obtain a copper tailings-rare earth dispersion.

[0063] S3: The copper tailings-rare earth dispersion is subjected to solid-liquid separation by centrifugal separation to obtain a copper tailings-rare earth precipitate.

[0064] S4: vacuum drying the copper tailings-rare earth precipitate at 70°C and a vacuum degree of 96.2KPa; then placing the dried copper tailings-rare earth precipitate in a rotary kiln, heating it to 250°C and keeping it for 1 hour, then continuing to heat it to 1000°C and keeping it for 4 hours, high-temperature roasting, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker with a particle size of 20um.

[0065] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 13:100. Example 4

[0066] A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 90 parts of copper tailings-rare earth oxide clinker, 10 parts of fly ash, 5 parts of boron nitride fiber, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.15 parts of ether-ester mixed polyurethane and 0.8 parts of polycarboxylic acid water reducer.

[0067] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding fluorocarbon cerium ore powder with a particle size of 5 μm into water to obtain a dispersion containing fluorine-containing rare earth ore powder, wherein the mass percentage of the fluorine-containing rare earth ore powder in the dispersion is 15%.

[0068] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder with a particle size of 90-100um after magnetic separation, the mass ratio of the copper tailings slag powder to the dispersion of the fluorine-containing rare earth ore powder being 1:3; then heating and stirring at a temperature of 150°C for 3 hours to fully stir and react the two to obtain a copper tailings-rare earth dispersion.

[0069] S3: separating the copper tailings-rare earth dispersion into solid and liquid by centrifugal separation to obtain a copper tailings-rare earth precipitate.

[0070] S4: vacuum drying the copper tailings-rare earth precipitate at 80°C and a vacuum degree of 98.6 KPa; then placing the dried copper tailings-rare earth precipitate in a rotary kiln, heating it to 300°C and keeping it for 2 hours, then continuing to heat it to 1100°C and keeping it for 5 hours, performing high-temperature roasting, and after cooling, grinding and screening to obtain copper tailings-rare earth oxide clinker with a particle size of 20 um.

[0071] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 15:100.

[0072] Comparative Example 1 A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 68 parts of copper tailings slag powder, 16 parts of fluorine-containing rare earth ore powder, 8 parts of fly ash, 4 parts of boron nitride fiber, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.1 parts of polyether polyurethane expansion agent and 0.6 parts of naphthalene series water reducer.

[0073] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 13:100.

[0074] Comparative Example 2 A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 84 parts of copper tailings slag powder, 8 parts of fly ash, 4 parts of boron nitride fiber, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.1 parts of polyether polyurethane expansion agent and 0.6 parts of naphthalene series water reducer.

[0075] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 13:100.

[0076] Comparative Example 3 A high-dosage copper tailings rare earth grouting material comprises the following raw materials in parts by weight: 84 parts of copper tailings-rare earth oxide clinker, 8 parts of fly ash, 4 parts of bentonite, 4 parts of Guangxi white mud, 0.1 parts of polyether polyurethane expansion agent and 0.6 parts of naphthalene series water reducer.

[0077] The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding fluorocarbon cerium ore powder with a particle size of 3 μm into water to obtain a dispersion containing fluorine-containing rare earth ore powder, wherein the mass percentage of the fluorine-containing rare earth ore powder in the dispersion is 12%.

[0078] S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder with a particle size of 70-90um after magnetic separation, the mass ratio of the copper tailings slag powder to the dispersion of the fluorine-containing rare earth ore powder being 1:2; then heating and stirring at a temperature of 140°C for 2 hours to fully stir and react the two to obtain a copper tailings-rare earth dispersion.

[0079] S3: The copper tailings-rare earth dispersion is subjected to solid-liquid separation by centrifugal separation to obtain a copper tailings-rare earth precipitate.

[0080] S4: vacuum drying the copper tailings-rare earth precipitate at 70°C and a vacuum degree of 96.2KPa; then placing the dried copper tailings-rare earth precipitate in a rotary kiln, heating it to 250°C and keeping it for 1 hour, then continuing to heat it to 1000°C and keeping it for 4 hours, high-temperature roasting, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker with a particle size of 20um.

[0081] The preparation method of the above-mentioned high-dosage copper tailings rare earth grouting material comprises the following steps: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 13:100.

[0082] Performance Test: (1) Liquidity test: Wipe the glass plate and the inner wall of the truncated cone mold with a damp cloth in advance, and place the truncated cone mold in the center of the glass plate, then quickly pour the grouting material obtained in Example 3 and Comparative Examples 1-3 into the truncated cone mold, and the slurry is flush with the upper mouth of the truncated cone mold. The truncated cone mold should comply with the provisions of the current national standard "Method for Determining the Fluidity of Cement Mortar" GB / T2419, with the dimensions of 100mm±0.5mm in the lower inner diameter, 70mm±0.5mm in the upper inner diameter, and 60mm±0.5mm in height; the size of the glass plate is not less than 500mmx500mm, and is placed on a horizontal test bench. Slowly lift the truncated cone mold, and the grouting material flows freely under undisturbed conditions until it stops. Use a caliper to measure the maximum diffusion diameter of the bottom surface and the diameter in the vertical direction, calculate the average value, and use it as the initial value of fluidity. The test result is accurate to 1mm, and is rounded to mm and the data is recorded. The initial value of fluidity should be checked within 6 minutes from the start of stirring to the end of measurement. After the initial fluidity value is measured, the grouting material on the glass plate is quickly placed in the stirring pot, and the stirring pot is covered with a damp cloth to prevent water evaporation. 30 minutes after the initial fluidity value is measured, the grouting material in the stirring pot is stirred for 240 seconds according to the fixed program of the mixer, and then the fluidity value is measured again as the 30-minute retention value of the fluidity, and the data is recorded. The specific results are shown in Table 1.

[0083] Table 1 Fluidity of different grouting materials

[0084] (2) Compressive strength test: The grouting materials obtained in Example 3 and Comparative Examples 1-3 were poured into a 40mm×40mm×160mm column to make cement mortar test pieces. The compressive strength test was carried out in accordance with the relevant provisions of the current national standard "Test Method for Strength of Cement Mortar (ISO Method)" GB / T17671. After demolding, the grouting materials were placed in (20±1)℃ water for curing for 1 day, 3 days and 28 days, and then the strength test was carried out. The specific results are shown in Table 2 below.

[0085] Table 2 Compressive strength of different specimens

[0086] It can be seen from Tables 1 and 2 above that the grouting material prepared by the present invention meets the national standards for the use of grouting materials, and the compressive strength and fluidity of the high-doped copper tailings rare earth grouting material prepared in Example 3 of the present invention are relatively good compared with those in Comparative Examples 1-3, especially the compressive strength. The grouting material obtained by the present invention after adding copper tailings and fluorine-containing rare earth ore to the modified clinker has a compressive strength significantly higher than that of the grouting material directly adding copper tailings and fluorine-containing rare earth ore, and compared with the grouting material without boron nitride fiber, the compressive strength of the high-doped copper tailings rare earth grouting material added with boron nitride fiber is also improved.

[0087] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-doped copper tailings rare earth grouting material, characterized in that: The invention comprises the following raw materials in parts by weight: 70-90 parts of copper tailings-rare earth oxide clinker, 5-10 parts of fly ash, 1-5 parts of boron nitride fiber, 3-8 parts of clay additive, 0.05-0.15 parts of expansion agent and 0.2-0.8 parts of water reducing agent.

2. The high-doped copper tailings rare earth grouting material according to claim 1, characterized in that: The method for preparing the copper tailings-rare earth oxide clinker comprises the following steps: S1: adding an appropriate amount of fluorine-containing rare earth mineral powder into water to obtain a dispersion containing the fluorine-containing rare earth mineral powder; S2: adding the dispersion of the fluorine-containing rare earth ore powder obtained in step S1 to the copper tailings slag powder after magnetic separation, and then heating and stirring to react to obtain a copper tailings-rare earth dispersion; S3: performing solid-liquid separation on the copper tailings-rare earth dispersion to obtain a copper tailings-rare earth precipitate; S4: drying the copper tailings-rare earth precipitate, calcining it at high temperature, cooling it, and grinding and screening it to obtain copper tailings-rare earth oxide clinker.

3. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: The fluorine-containing rare earth ore powder is bastnaesite powder, or Mixed rare earth mineral powder of bastnaesite and monazite; The copper tailings slag powder includes the following chemical components by weight: SiO2 30-70 parts; Fe2O3 10-15 parts; Al2O3 8-12 parts; CaO 5-10 parts; S03 5-15 parts; The particle size of the fluorine-containing rare earth ore powder is 0.1-5um; the particle size of the copper tailings slag powder is 50-100um; The particle size of the copper tailings-rare earth oxide clinker obtained by grinding and screening is 10-20um.

4. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: In step S1, the mass percentage of the fluorine-containing rare earth mineral powder in the dispersion containing the fluorine-containing rare earth mineral powder is 5-15%.

5. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: In step S2, the mass ratio of the copper tailings powder to the dispersion of the fluorine-containing rare earth ore powder is 1:1-3.

6. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: In step S2, the temperature of the heating and stirring reaction is 120-150° C. and the time is 1-3 hours.

7. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: The solid-liquid separation operation in step S3 adopts filtration or centrifugation.

8. The high-doped copper tailings rare earth grouting material according to claim 2, characterized in that: In step S4, Drying conditions: vacuum drying at 60-80°C and vacuum degree of 93.3-98.6KPa; The high temperature roasting conditions are as follows: placing the dried copper tailings-rare earth precipitates in a rotary kiln, then heating to 200-300°C and keeping the temperature for 0.5-2h, then continuing to heat to 900°C-1100°C and keeping the temperature for 3-5h.

9. The high-doped copper tailings rare earth grouting material according to claim 1, characterized in that: The clay additive is a mixture of bentonite and Guangxi white mud, and the mass ratio of the bentonite to the Guangxi white mud is 0.5-1:1; The expansion agent is one of polyether type, polyester type, and ether-ester mixed polyurethane; The water reducer is one of a sodium lignin sulfonate water reducer, a naphthalene-based water reducer and a polycarboxylic acid water reducer.

10. A method for preparing a high-dosage copper tailings rare earth grouting material, characterized in that: The steps include: S1: weighing the raw materials according to the raw material ratio of the high-doped copper tailings rare earth grouting material according to claim 1, and mixing the weighed raw materials evenly to obtain a high-doped copper tailings rare earth grouting dry powder; S2: adding water to the high-doped copper tailings rare earth grouting dry powder evenly mixed in step S1, and then fully stirring to obtain a high-doped copper tailings rare earth grouting material; wherein the mass ratio of water to the high-doped copper tailings rare earth grouting dry powder is 10-15:100.

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