Mining spraying material with high solid waste mixing amount as well as preparation method and application thereof

Abstract

The invention discloses a mining spraying material with high solid waste mixing amount as well as a preparation method and application thereof, and belongs to the technical field of mining spraying materials. The mining spraying material with the high solid waste mixing amount, which is prepared by matching the stone chips with the cement, the mineral powder, the silica fume, the zeolite powder and the wollastonite powder under the condition of a set component proportion and through a set preparation method, has excellent performances of flame retardance, static electricity resistance, compact and uniform spraying layer, relatively low spraying rebound rate and the like, and is good in operability in a specific implementation process; the problems that in the prior art, the construction technology is complex, the spraying speed is low, the rebound rate is high, and the dust concentration is large can be solved. Meanwhile, the strength of the obtained mining spraying material can reach 50 MPa or above, the bonding performance is excellent, the problem that in the prior art, a spraying material is low in early strength is solved, and the mining spraying material can be suitable for underground operation with complex working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine spraying materials, in particular to a mine spraying material with high solid waste content and a preparation method and application thereof. BACKGROUND

[0002] In order to ensure the safety of mine production, effective measures need to be taken to prevent weathering of surrounding rocks of construction roadway and corrosion of metal support, and the newly excavated roadway needs to be closed in time. Generally, spraying materials are used to prevent weathering of surrounding rocks of construction roadway and corrosion of metal support, and to close the newly excavated roadway. At present, the spraying materials used in the specific construction process have problems such as complex construction process, slow spraying speed, high rebound rate, high dust concentration and low early strength, which are difficult to meet the needs of rapid support of underground operation, and seriously affect the construction efficiency and safety. At the same time, the existing spraying materials are also difficult to meet the complex working conditions of underground operation in terms of adhesion. SUMMARY

[0003] The main purpose of the present application is to provide a mine spraying material with high solid waste content and a preparation method and application thereof, which aims to solve the problems of the existing spraying materials in the specific construction process, such as complex construction process, slow spraying speed, high rebound rate, high dust concentration and low early strength, and in terms of adhesion, which are difficult to meet the complex working conditions of underground operation.

[0004] In order to achieve the above purpose, the present application provides a mine spraying material with high solid waste content, which comprises cement, mineral powder, stone chips, silica fume, zeolite powder and wollastonite powder.

[0005] Optionally, the amount of each component in the mine spraying material is as follows: cement 17% to 28%, mineral powder 6% to 17%, stone chips 60% to 70%, silica fume 2% to 6%, zeolite powder 0.5% to 3.0%, and wollastonite powder 0.5% to 3.0%.

[0006] Optionally, the amount of each component in the mine spraying material is as follows: cement 20% to 25%, mineral powder 10% to 15%, stone chips 65% to 68%, silica fume 3% to 5%, zeolite powder 1.0% to 2.0%, and wollastonite powder 1.0% to 2.0%.

[0007] Optionally, the amount of each component in the mine spraying material is as follows: cement 25%, mineral powder 6.0%, stone chips 65%, silica fume 2%, zeolite powder 1.0%, and wollastonite powder 1.0%.

[0008] In order to achieve the above purpose, the present application also provides a preparation method of a mine spraying material with high solid waste content, which comprises the following steps: The zeolite powder is weighed by mass parts, and then ground to obtain zeolite powder with a particle size of less than 3.64 microns; The zeolite powder is activated to obtain the zeolite powder after activation treatment; The cement, mineral powder, stone chips, silica fume and wollastonite powder are weighed by mass parts respectively, and are put into a stirrer, and are mixed uniformly after a preset stirring time, to obtain a dry powder mixture; The zeolite powder after activation treatment is added to the dry powder mixture, and then water is added according to a preset water-material ratio, and the stirring is continued until uniform, to obtain the mine spraying material with high solid waste content.

[0009] Optionally, the activation treatment is realized by the following method: The zeolite powder is calcined at a preset calcination temperature for a preset calcination time; The zeolite powder after calcination is soaked in an alkali solution with a preset concentration and a preset temperature, and is dried after soaking for a preset soaking time.

[0010] Optionally, the preset water-material ratio is 0.15-0.20:1.

[0011] Optionally, the preset calcination temperature is 260-350 DEG C, the preset calcination time is 0.5-1.0 h, the preset concentration is 1.0-4.0%, the preset soaking temperature is 45-85 DEG C, and the preset soaking time is 0.8-1.5 h.

[0012] In order to achieve the above purpose, the application also provides an application of the mine spraying material with high solid waste content, which is prepared by the above preparation method and is applied in underground operation.

[0013] Optionally, in the underground operation, the spraying thickness of the mine spraying material is 2-10 mm, and the spraying is maintained for 24-48 h under the conditions of humidity>80% and temperature of 10-35 DEG C.

[0014] Compared with the prior art, the application can achieve the following beneficial effects: 1. In the technical solution of the present application, by matching stone chips with cement, mineral powder, silica fume, zeolite powder and wollastonite powder, under the condition of a set component ratio, and through a set preparation method, the obtained high solid waste content mine spraying material has excellent properties such as flame retardant and antistatic, uniform and dense spraying layer, and low rebound rate, and is good in operability in the specific implementation process, and can solve the problems of complex construction process, slow spraying speed, high rebound rate and high dust concentration in the prior art. At the same time, the strength of the obtained mine spraying material can reach more than 50MPa, the bonding performance is excellent, the problem of low early strength of the spraying material in the prior art is solved, and the mine spraying material can be applied to complex downhole operation.

[0015] 2. In the component of the solid waste content mine spraying material disclosed in the present application, the amount of cement is significantly reduced compared with the existing spraying material, which not only can effectively reduce carbon emissions and protect the environment, but also can improve the utilization rate of mineral powder, zeolite powder and silica fume, is conducive to waste recycling, and meets the concept of sustainable development. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Preparation method flowchart of the high solid waste content mine spraying material. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0018] In order to solve the problems of complex construction process, slow spraying speed, high rebound rate, high dust concentration and low early strength of the mine spraying material in the prior art, and the problem that the bonding performance is difficult to meet the complex working condition of downhole operation, the present application provides a high solid waste content mine spraying material, which comprises cement, mineral powder, stone chips, silica fume, zeolite powder and wollastonite powder.

[0019] In a possible embodiment, the amount of each component in the above-mentioned mine spraying material is as follows: cement 17% to 28%, mineral powder 6% to 17%, stone chips 60% to 70%, silica fume 2% to 6%, zeolite powder 0.5% to 3.0%, and wollastonite powder 0.5% to 3.0%.

[0020] In a possible implementation, the mine spraying material comprises the components in the following amounts: cement 20% to 25%, mine powder 10% to 15%, stone chips 65% to 68%, silica ash 3% to 5%, zeolite powder 1.0% to 2.0%, and silica ash powder 1.0% to 2.0%.

[0021] In a possible implementation, the mine spraying material comprises the components in the following amounts: cement 25%, mine powder 6.0%, stone chips 65%, silica ash 2%, zeolite powder 1.0%, and silica ash powder 1.0%.

[0022] Optionally, the cement can be P.O 42.5 grade cement.

[0023] Optionally, the mine powder can be S95 grade mine powder.

[0024] Optionally, the average particle size of the stone chips is 5 mm.

[0025] It should be noted that in the above high solid waste content mine spraying material, through the interaction between cement, mineral powder, stone chips, silica fume, zeolite powder and wollastonite powder, a spraying material with excellent mechanical properties, stable and easy to operate construction performance, low cost and environmental protection can be obtained. Among them, the cement content of 17% to 28% is lower than that in the prior art, and through the cooperation with other components, the early setting and strength requirements of the spraying material can be met, and the problem of wall cracking caused by excessive cement content can be avoided. The stone chips of 60% to 70% as aggregate can fill the internal voids of the material, reduce the amount of cementitious material, and at the same time can form close packing with cement and mineral powder, thereby improving the density and strength of the material coating. The 6% to 17% of the mineral powder reacts with the calcium hydroxide generated by the hydration of the cement to form calcium silicate hydrate (C-S-H) gel, which can improve the late strength and impermeability of the material. The 2% to 6% of the silica fume can fill the small voids between the cement and mineral powder particles to further optimize the density and enhance the adhesion between the coating and the surrounding rock. Therefore, the components of the above high solid waste content mine spraying material are not simply mixed, but through the synergistic mechanism of filling, active compensation and performance optimization, the performance of the spraying material is improved as a whole, which is specifically manifested as follows: the stone chips as coarse aggregate can fill the macroscopic voids of the material; the particle size of the silica fume is nanoscale, which can fill the microscopic voids between the cement and the mineral powder; the zeolite powder has both filling and adsorption effects, which can adsorb part of the free water and reduce the porosity; the three can realize multi-scale void filling from millimeter, micrometer and nanometer levels, which can greatly improve the coating density and further enhance the impermeability and strength. In terms of strength synergy, the cement will quickly set after spraying, which can avoid the coating from falling off and provide early strength; the mineral powder can provide medium-term strength and can make up for the short board of medium-term strength caused by insufficient cement content through secondary hydration reaction (reaction with calcium hydroxide); the silica fume can improve the late strength and adhesion, and its high activity can combine with the hydration products to form a more dense C-S-H gel network; the three can make the above spraying material have stable construction performance. In addition, the wollastonite powder generally has a needle-like structure, which can enhance the coating toughness of the spraying material and reduce the risk of cracking after hardening, and its low oil absorption can improve the flowability of the material and avoid pipe blockage during spraying; the zeolite powder has the function of adsorbing free water, which can adjust the setting time of the coating and avoid the problem of slow setting caused by underground humidity.

[0026] Further, when the use amount of each component in the mine spraying material comprises cement 20%~25%, mineral powder 10%~15%, stone chips 65%~68%, silica fume 3%~5%, zeolite powder 1.0%~2.0% and silica fume stone powder 1.0%~2.0%, the mechanical properties of the material can be more stable, the supporting reliability is improved; in the specific construction process, it is more controllable, and can adapt to complex underground operation; the compressive strength of the spraying material can be stabilized at 20~25 MPa in 1 day, the bonding strength is greater than or equal to 2.1 MPa, the cracking rate is less than 1% after maintenance, and the workload of the secondary plugging and spraying operation caused by cracking can be reduced.

[0027] Further, in the mine spraying material, the average particle size of the stone chip particles is less than or equal to 5 mm, which can form a close packing of coarse and fine particles with cement and mineral powder, and the use amount of 65%~68% can exactly fill the internal macroscopic voids of the material, and at the same time provide an attachment skeleton for other active components. If the stone chips are replaced by other aggregates, such as river sand, etc., the particle density will not match other components, which will cause the coating density, early strength and construction controllability of the spraying material to decrease significantly. If the use amount of stone chips is reduced, in order to make up for the strength, the use amount of cement or silica fume needs to be increased, which not only causes the cost to increase greatly, but also reduces the early strength of the material coating. If the use amount of stone chips is increased, for example, the use amount is greater than 70%, the coating adhesion will decrease due to the lack of cementitious materials, and the coating is easy to peel off.

[0028] Further, in the mine spraying material, when the cement is 25%, the mineral powder is 6.0%, the stone chips are 65%, the silica fume is 2%, the zeolite powder is 1.0% and the silica fume stone powder is 1.0%, the performance of the spraying material can be further improved, specifically, under the condition of the formula, the 28-day compressive strength of the spraying material can be stabilized at 50~55 MPa, the bonding strength can reach 2.1~2.3 MPa, the spraying material is not easy to peel off with the rock, and additional anchor spraying is not needed, which can reduce the construction process; the crack resistance and durability of the material coating can be significantly improved, which can effectively seal the surrounding rock cracks and long-term prevent water seepage and air leakage, etc., which can avoid the problems of coating weathering and strength attenuation caused by moisture, and prolong the service life of the spraying material; and the spraying is easy, the setting is easy, and the problem of pipe blockage will not occur.

[0029] In order to achieve the above purpose, the application further provides a preparation method of a mine spraying material with a high solid waste content, as shown in Figure 1 The preparation method comprises the following steps: S10. The zeolite powder is weighed according to the mass fraction, and then ground to obtain zeolite powder with a particle size of less than 3.64 μm; S20. The zeolite powder is activated to obtain the activated zeolite powder; S30. The cement, mineral powder, stone chips, silica fume and wollastonite powder are weighed by mass fraction, put into a stirrer, mixed uniformly after a preset stirring time, and a dry powder mixture is obtained; S40. The zeolite powder after activation treatment is added to the dry powder mixture, then water is added according to a preset water-material ratio, and stirring is continued until uniform, and the high solid waste content mine spraying material is obtained.

[0030] Optionally, the above-mentioned preset stirring time can be 3-5 min.

[0031] It should be noted that in the process of preparing the high solid waste content mine spraying material, the zeolite is first ground and then activated, which can increase the specific surface area of the zeolite powder and generate more active sites. If the modification is to mix all other components first and then activate, the problem of components such as stone chips hindering the activation will occur, which will lead to insufficient activity of the zeolite powder and cannot play the function of adsorbing free water and optimizing the density. Secondly, the solid components such as cement, mineral powder and stone chips are first mixed uniformly, and then the activated zeolite powder and water are added, which can avoid the problem of premature mixing of wet materials leading to setting; and the dry powder mixture is convenient for storage and transportation on site, and only needs to be stirred with water in proportion during construction, and the preparation of the spraying material can be completed after a preset time, thereby greatly shortening the underground construction time. In addition, the activated zeolite powder is added separately to the dry powder mixture, which can be uniformly dispersed in the system, and its adsorbability can adjust the cement hydration speed to avoid cracking of the coating layer due to too fast hydration; at the same time, its microporous structure can fill the small gaps and form a multi-scale dense network with silica fume and stone chips, so that the permeability coefficient of the material is significantly reduced, thereby improving the wind and water resistance. If the silica fume and wollastonite powder are mixed with the cement, mineral powder and stone chips first, a dry mixed powder is formed, which can avoid the problems of silica fume agglomeration and wollastonite powder structure damage caused by long-term contact with water after mixing with water first; and the premixing process can allow the silica fume to uniformly fill the gaps between the cement particles and the wollastonite powder to form a fiber skeleton, thereby ensuring the strength and crack resistance of the material; if all components are mixed at one time, the performance of the spraying material will be reduced.

[0032] In one possible implementation, the above-mentioned activation treatment is realized by the following method: The zeolite powder is subjected to calcination treatment at a preset calcination temperature for a preset calcination time; The zeolite powder after calcination treatment is soaked in an alkali solution with a preset concentration at a preset soaking temperature, and then dried after a preset soaking time.

[0033] Optionally, when the activation treatment is performed, a muffle furnace, i.e. a box-type resistance furnace, can be selected as the calcination equipment; and when the alkali solution is soaked, a jacketed stirring reaction kettle can be selected.

[0034] In one possible implementation, the above-mentioned preset water-material ratio is 0.15-0.20:1.

[0035] In a possible implementation, the preset calcination temperature is 260-350°C, the preset calcination time is 0.5-1.0h, the preset concentration is 1.0%-4.0%, the preset soaking temperature is 45-85°C, and the preset soaking time is 0.8-1.5h.

[0036] It should be noted that, in the step of the activation treatment, when the preset calcination temperature is 260-350°C, water, carbon dioxide and a small amount of organic impurities adsorbed in the pores of the zeolite powder can be quickly removed without causing the collapse of the crystal structure, so that more microporous structures can be retained to provide channels for subsequent penetration of the alkali solution. When the concentration of the alkali solution is 1.0%-4.0%, the alkali solution can slowly penetrate into the interior of the zeolite powder under the condition that the preset soaking temperature is 45-85°C, and a mild reaction occurs with the silicate framework to dissolve part of the calcium ions and aluminum ions and generate a large number of hydroxyl (-OH) active sites. After the preset soaking time of 0.8-1.5h, the reaction depth can be controlled to avoid excessive dissolution of the framework caused by high-concentration alkali solution or long time, so that the zeolite powder can still play the functions of adsorbing free water and filling voids.

[0037] Further, the activated zeolite powder can have a synergistic effect with cement and silica ash to form multi-scale filling. The needle-like structure of the silica ash and the toughness of the activated zeolite powder can significantly reduce the cracking rate of the sprayed coating and significantly improve the early strength and bonding strength of the sprayed material. When the preset water-material ratio is 0.15-0.20:1, the fluidity of the material can be ensured without causing an increase in porosity after hardening due to excessive water.

[0038] Further, in the activation treatment, if the calcination temperature is >350°C or the calcination time is >1.0h, not only the crystal structure of the zeolite powder will collapse excessively and the micropores will be damaged, losing the functions of adsorbing free water and filling voids, but also the silicate framework on the surface of the zeolite powder will be excessively broken, which will be excessively dissolved during subsequent alkali immersion and become amorphous powder. Finally, the compactness of the obtained sprayed material will be significantly reduced, the windproof and waterproof effects will be poor, and the toughness of the coating will be reduced. If the calcination temperature is <260°C or the calcination time is <0.5h, the water and organic impurities in the pores of the zeolite powder cannot be completely removed, the active sites are blocked, the pore channels are not fully opened, the subsequent alkali solution cannot penetrate into the interior, and the activation is insufficient. The activity of the zeolite powder is insufficient, the material strength cannot be improved by the synergistic effect of the zeolite powder, cement and silica ash, and the adhesion decreases.

[0039] Further, during soaking, if the alkali concentration > 4.0%, the temperature > 85℃ or the soaking time > 1.5h, the zeolite powder surface will be excessively eroded, a large amount of soluble salt will be generated, and the material will be hygroscopic after drying, which will cause the material to return to alkali and the strength to decrease in the later period; at the same time, the particle structure of the zeolite powder will be damaged, losing the role of filling the voids; eventually, the coating surface of the sprayed material will return to alkali, so that the bonding force of the surrounding rock will decrease significantly, causing the coating to fall off. If the alkali concentration < 1.0%, the temperature < 45℃ or the soaking time < 0.8h, the zeolite powder surface cannot be effectively etched, the amount of active sites generated is insufficient, the reaction speed between the other components is too slow, the silicate skeleton is not opened moderately, and it cannot be combined with the cement hydration product, etc., so that the zeolite powder is equivalent to ineffective filler, which will eventually cause the early strength of the obtained sprayed material to decrease significantly, so that it cannot cope with the pressure of the surrounding rock in the well.

[0040] Further, the above-mentioned preset water-material ratio realizes a unique balance point of the flowability and the density of the sprayed material, if the water-material ratio > 0.20:1, under the conditions of the technical scheme of the present application, the flowability of the material will be too strong, and the material will flow during spraying, which cannot be attached to the vertical or inclined surrounding rock surface; and the excess water will cause the coating surface to sand, affecting the subsequent supporting effect. At the same time, during the hardening process of the coating, the evaporation of a large amount of water will form a large number of micropores, which will cause the material density and the compressive strength to decrease sharply; and the shrinkage rate will increase during drying, so that the coating will have penetrating cracks and lose the supporting effect. If the water-material ratio < 0.15:1, the material will be too dry and thick, the flowability will be poor, the pipe will be easily blocked during passing through the spraying equipment, frequent shutdown and cleaning will be required, and the construction will be interrupted in severe cases; and the coating surface will be rough after spraying, there will be a large number of bubbles, and a continuous and dense protective layer cannot be formed. At the same time, the cement and other cementitious materials cannot be fully hydrated, so that there are a large number of unhydrated particles in the material, which will cause the early compressive strength and the bonding strength to decrease significantly; at the same time, the coating has many internal voids and poor impermeability, which cannot resist the humid environment in the well and is easy to weather and peel off.

[0041] From the above analysis, it can be seen that in the technical scheme of the present application, there is a synergistic effect between the water-material ratio and the process parameters of each step during the activation treatment process of the zeolite powder, and if any parameter is changed, the performance of the final obtained mine sprayed material will decrease significantly.

[0042] In order to achieve the above-mentioned purpose, the present application also provides an application of a mine sprayed material with a high solid waste content, which is prepared by the above-mentioned preparation method and applied to underground operations.

[0043] In a possible implementation, the spraying thickness of the above-mentioned mine sprayed material is 2mm~10mm, and the sprayed material is cured for 24h~48h under the conditions of humidity > 80% and temperature 10℃~35℃ after spraying.

[0044] It should be noted that in the high solid waste content mine spraying material obtained by the technical scheme of the present application, the adsorption of the zeolite powder after activation treatment can adjust the hydration speed between components, and the synergy of silica fume and mine powder can improve the water resistance. Even in the underground environment with humidity > 80% and temperature 10℃~35℃, it can also normally condense and harden, and will not cause whitening and strength attenuation due to humidity. Or because of temperature fluctuations, it can crack due to too fast condensation, or it can collapse due to too slow condensation. Compared with the existing spraying material, the spraying material obtained by the present application can be cured for 24h~48h after curing in a humidity > 80% and temperature 10℃~35℃ environment, and the surface is dense, without sanding and powder falling phenomenon, and can withstand the humid environment in the mine for a long time. Secondly, in the mine spraying material, the solid waste such as mine powder, stone chips and zeolite powder accounts for 73%, and the cement content is ≤28%, which can significantly reduce the material cost and save the huge expenditure of long-term large-scale underground operation. It also meets the requirements of green mine construction and reduces carbon emissions caused by cement production. Compared with ordinary concrete, the spraying material obtained by the present application can meet the requirements of underground operation when the spraying thickness is 2mm~10mm, which not only can reduce the amount of material, but also can shorten the spraying operation time, especially suitable for the scene of rapid rescue in the mine. After 24h~48h of curing, it can ensure that the material is fully hydrated, and avoid the problem of strength attenuation caused by insufficient curing.

[0045] Example 1 A high solid waste content mine spraying material, comprising cement 17%, mine powder 11%, stone chips 60%, silica fume 6%, zeolite powder 3.0% and silica fume stone powder 3.0%; the preparation method comprises the following steps: S10. 3.0% of zeolite powder is weighed by mass fraction, then ground to obtain zeolite powder with a particle size of less than 3.64μm; S20. The zeolite powder obtained in S10 is activated to obtain activated zeolite powder, which is realized based on S201~S202, specifically: S201. The zeolite powder is placed in a muffle furnace, then slowly heated to 260℃, kept for 1.0h, and then slowly cooled to room temperature; S202. The zeolite powder obtained in S201 is soaked in a jacketed stirring reaction kettle containing 1.0% alkali solution, slowly heated to 45℃, then soaked for 1.5h, and stirred during the soaking process; S30. 17% of cement, 11% of mine powder, 60% of stone chips, 6% of silica fume and 3.0% of silica fume stone powder are weighed by mass fraction respectively, then put into a stirrer, stirred for 3min, then mixed uniformly to obtain a dry powder mixture; S40. Add the activated zeolite powder obtained in S20 to the dry powder mixture obtained in S30, and add water according to a water-material ratio of 0.15:1, and continuously stir until uniform.

[0046] Through S10-S40, a high-solid-waste-content mine spraying material is obtained.

[0047] The obtained high-solid-waste-content mine spraying material is applied to underground operations, with a spraying thickness of 2-10 mm, and is cured for 24-48 h under a humidity of >80% and a temperature of 10-35℃ after spraying.

[0048] In the specific operation process, the rebound rate of the spraying material is determined, and the compressive strength, flexural strength, flame retardant and antistatic properties, and bonding strength of the cured spraying material at different time periods are determined, and the results are shown in Table 1.

[0049] Example 2 A high-solid-waste-content mine spraying material, comprising cement 28%, mine powder 17%, stone chips 50%, silica fume 2%, zeolite powder 1.5%, and wollastonite powder 1.5%; the preparation method comprises the following steps: S10. 1.5% of zeolite powder is weighed according to the mass fraction, and then ground to obtain zeolite powder with a particle size of less than 3.64 μm; S20. The zeolite powder obtained in S10 is activated to obtain activated zeolite powder, which is realized based on S201-S202, and specifically: S201. The zeolite powder is placed in a muffle furnace, and then slowly heated to 350℃, and after 0.5 h of heat preservation, slowly cooled to room temperature; S202. The zeolite powder obtained in S201 is soaked in a jacketed stirring reaction kettle containing 4.0% alkali solution, slowly heated to 85℃, and then soaked for 0.8 h, and stirring is performed during the soaking process; S30. Cement 28%, mine powder 17%, stone chips 50%, silica fume 2%, and wollastonite powder 1.5% are weighed according to the mass fraction, respectively, and are put into a stirrer, and after 5 min of stirring, they are mixed uniformly to obtain a dry powder mixture; S40. Add the activated zeolite powder obtained in S20 to the dry powder mixture obtained in S30, and add water according to a water-material ratio of 0.20:1, and continuously stir until uniform.

[0050] Through S10-S40, a high-solid-waste-content mine spraying material is obtained.

[0051] The obtained high solid waste content mine spraying material is applied to underground operation, the spraying thickness is 2mm-10mm, and the sprayed material is maintained for 24h-48h under the condition that the humidity is greater than 80% and the temperature is 10℃-35℃.

[0052] In the specific operation process, the rebound rate of the spraying material is determined, and the compressive strength, the bending strength, the fire resistance and the antistatic performance, and the bonding strength of the sprayed material after maintenance in different time periods are determined, and the results are shown in Table 1.

[0053] In the determination of the compressive strength and the bending strength, the compressive and bending strength test of the material is performed by using a compressive and bending strength integrated machine according to the standard of GB / T17671 “Cement mortar strength test method”. The bonding strength is determined according to JGJ / T70 “Building mortar basic performance test method”, and the bonding strength between the coating and the base surface is tested by using a bonding strength tester. The fire resistance and the antistatic performance test are respectively performed by using an alcohol lamp test and a surface resistance test. The rebound rate is determined by using a rebound tester.

[0054] Table 1

[0055] From the data in the table, it can be seen that the early strength of the obtained sprayed material is far more than 10 MPa, which is 2.4 times more than the standard value; at the same time, the early bending strength is also much higher than the standard value. This shows that the sprayed material obtained by the application can quickly form a protective layer with sufficient strength after spraying a thickness of 2 mm to 10 mm, curing for 24 h to 48 h under the conditions of humidity > 80% and temperature of 10℃ to 35℃, can timely meet the temporary support requirements after the excavation of the underground roadway, can avoid the collapse of surrounding rock due to insufficient early strength, and can greatly shorten the waiting time of underground operation. Secondly, the long-term strength of 28 d is significantly higher than the standard value; at the same time, the long-term bending strength of 28 d is more than 2 times the standard value; this shows that the sprayed material obtained by the application has a compact structure and strong stability after hardening, can withstand the pressure of surrounding rock and environmental erosion for a long time, can avoid support failure due to strength decay in the later period, and can reduce the secondary maintenance cost. In addition, the rebound values of the sprayed materials of examples 1 and 2 are both at very low values, and the low rebound rate means that most of the material can effectively adhere to the surface of the surrounding rock during the spraying process, which can reduce the waste of material caused by rebound, reduce the cleaning workload of the rebound material in the underground, and improve the construction efficiency. In the underground operation, there are risks of flammability and static electricity, and the sprayed materials obtained by the examples meet the use standards, which shows that the sprayed materials will not cause sparks due to static electricity accumulation when used in the underground, and will not assist combustion in a fire, which can effectively avoid safety hazards such as fire and explosion in the underground. In terms of bonding strength, the sprayed materials obtained by the examples are significantly higher than the technical requirements, which can ensure that the material can adhere tightly to the surface of the surrounding rock after spraying, and even when the surrounding rock is slightly deformed or vibrates, the coating is not easy to peel off, avoiding the problem of support leakage caused by bonding failure.

[0056] Example 3 A mine sprayed material with a high solid waste content, comprising cement 25%, mine powder 6.0%, stone chips 65%, silica fume 2%, zeolite powder 1.0% and wollastonite powder 1.0%; the preparation method comprises the following steps: S10. 1.0% of zeolite powder is weighed by mass fraction, and then ground to obtain zeolite powder with a particle size of less than 3.64 μm; S20. The zeolite powder obtained in S10 is activated to obtain activated zeolite powder, which is realized based on S201-S202, specifically: S201. The zeolite powder is placed in a muffle furnace, then slowly heated to 300℃, kept for 0.8 h, and then slowly cooled to room temperature; S202. The zeolite powder obtained in S201 is soaked in a jacketed stirring reaction kettle containing 1.2% alkali liquor, slowly heated to 55℃, and then soaked for 1.0 h, and stirring is carried out during the soaking process; S30. Respectively, 25% of cement, 6.0% of slag, 65% of stone chips, 2% of silica fume and 1.0% of silica stone powder are weighed by mass fraction and put into a stirrer, and after 5 minutes of stirring, they are uniformly mixed to obtain a dry powder mixture; S40. The zeolite powder after activation treatment obtained in S20 is added to the dry powder mixture obtained in S30, and water is added according to a water-material ratio of 0.18:1, and stirring is continued until uniform.

[0057] Through S10-S40, a high-solid-waste-content mine spraying material is obtained.

[0058] The obtained high-solid-waste-content mine spraying material is applied to underground operations, with a spraying thickness of 2mm-10mm, and after spraying, it is cured for 24h-48h under humidity>80% and temperature of 10℃-35℃.

[0059] In the specific operation process, the rebound rate of the spraying material is measured, and the compressive strength, flexural strength, flame retardant and antistatic properties, and bonding strength of the sprayed material after curing at different time periods are measured, and the results are shown in Table 2.

[0060] Table 2

[0061] By comparing and analyzing the data in Table 1 and Table 2, it can be seen that the 1d early compressive strength, early flexural strength, 28d long-term compressive strength and long-term flexural strength of the high-solid-waste-content mine spraying material obtained in Example 3 are not only better than those of Examples 1 and 2, but also significantly better than the standard values; this shows that in the technical scheme of Example 3, the synergistic effect between each step and its process parameters is the strongest, and the performance of the spraying material can be further improved.

[0062] Comparative Example 1 is set under Example 3 In Comparative Example 1, the zeolite powder is not subjected to activation treatment. The remaining technical features are the same as those of Example 3.

[0063] Comparative Example 2 is set under Example 3 In Comparative Example 2, the S40 step is omitted, and the activated zeolite powder obtained in S20 is mixed with the powders of each component powder weighed in S30 at one time, and water is added and stirred until uniform. The remaining technical features are the same as those of Example 3.

[0064] Comparative Example 3 is set under Example 3 In Comparative Example 3, fly ash is used to replace zeolite powder, and river sand is used to replace stone chips. The remaining technical features are the same as those of Example 3.

[0065] The spraying material obtained in Comparative Example 1~3 is applied to downhole operation, the spraying thickness is 2mm~10mm, and the spraying material is maintained for 24h~48h after spraying under humidity >80%, temperature 10℃~35℃. In the specific operation process, the rebound rate of the spraying material is determined; and the compressive strength, flexural strength, flame retardant and antistatic properties and bonding strength of the sprayed material after curing at different time periods are determined, and the results are shown in Table 3.

[0066] Table 3

[0067] By comparing and analyzing the data in Table 1, Table 2 and Table 3, it can be seen that compared with Examples 1~3, the early compressive strength, flexural strength and long-term early compressive strength, flexural strength of the spraying material obtained in Comparative Example 1 are significantly reduced, and the bonding strength, flame retardant, antistatic properties do not meet the standard, because the pores of the zeolite powder without activation treatment are blocked by impurities, and there is no active site, so it cannot produce a synergistic effect with cement, silica fume and other components, fill the voids, promote the hydration reaction, resulting in a decrease in material density, and then affect the strength, flame retardant, antistatic and bonding strength and other properties of the material. In Comparative Example 2, because all components are mixed at one time, it will lead to uneven dispersion between the activated zeolite powder and the stone chips and silica fume, and at the same time, the zeolite powder in some areas is agglomerated and cannot play a filling role, and the voids are more in some areas without zeolite powder; and water is added at one time during the mixing, which will cause the cement to hydrate too early, and subsequent stirring cannot form a uniform system, so that the internal structure of the material is loose, and finally the strength, flame retardant, antistatic and rebound rate of the obtained spraying material are significantly reduced. In Comparative Example 3, fly ash is used instead of zeolite powder, and river sand is used instead of stone chips, because the adsorption and activity of fly ash are lower than those of activated zeolite powder, it cannot adjust the hydration speed and fill the voids; and the composition of river sand and downhole surrounding rock is quite different, and the thermal expansion coefficient is not matched, and the particle size distribution is not compatible with cement and mineral powder, which will lead to low material density and poor adhesion with surrounding rock, and at the same time, river sand and fly ash do not contain flame retardant and antistatic components, so that the performance of the final obtained spraying material is significantly reduced, and it cannot meet the safety requirements of downhole.

[0068] It can be known from the analysis of examples 1-3 and comparative examples 1-3 that, in the technical scheme of the present application, the activated zeolite powder in the mine spraying material with a high solid waste content has a synergistic effect with cement, silica fume and mineral powder, which is specifically reflected in that the microporous structure of the activated zeolite powder can fill the gaps between cement and silica fume, the active sites thereof can react with the hydration product (calcium hydroxide) of cement to generate C-S-H gel, and silica fume (nanoscale) can further fill the micropores of the zeolite powder, and mineral powder (micron scale) can supplement the medium-term strength, so that the three can form a synergistic path of “multi-scale dense network + continuous hydration reaction” with cement, thereby ensuring the early and long-term strength of the spraying material. Secondly, there is also a synergistic effect between the stone chips and other components, the particle size distribution (0.15-5mm) of the stone chips (65%-68%) can form a tight packing with cement, mineral powder and silica fume, and the stone chips are consistent with the composition of the surrounding rock in the mine and have a matching thermal expansion coefficient, so that the coating can be prevented from cracking; and the stone chips are self-produced solid waste of the mine, and have a rough surface, which can enhance the adhesion with the cementitious system. In addition, the synergistic effect between the components is also reflected in the synergy of components and functions, and the components such as activated zeolite powder, silica fume and mineral powder contain flame-retardant and antistatic components (such as silico-aluminate), which can form a dense structure with cement and mineral powder to prevent oxygen flow, so that the obtained spraying material can not only meet the standard value, but also be better than the standard value.

[0069] In addition to the above, in the technical scheme of the present application, there is a synergistic effect between the process steps when preparing the mine spraying material, and the distribution and mixing of the components and the activation parameters can ensure the dispersibility and activity of the spraying material. Specifically, the zeolite powder is first ground to <3.64 μm, and then activated under a set condition, which can maximize the activity thereof; the activated zeolite powder is then added to the dry powder mixture, which can avoid agglomeration between the components, realize uniform dispersion of the components, ensure that each gap is filled with zeolite powder, and each active site can participate in the reaction. The water-material ratio of 0.15-0.20:1 can balance the fluidity and density of the spraying material, and the step-by-step mixing can avoid premature hydration of cement, ensure uniform contact between water and material, and ensure that the hydration reaction is sufficient and there is no loose area in the material. In specific underground operations, the low spraying rebound rate is due to the good fluidity and adhesion of the material, which ensures effective adhesion during spraying and reduces waste; at the same time, the early high strength can produce a supporting effect after spraying, which adapts to the fast pace of underground operations. The dense structure of the spraying material can not only improve the strength and adhesion, but also prevent oxygen flow and reduce static electricity accumulation, so that the material can meet the core requirements of supporting strength and flame-retardant and antistatic properties in the mine.

[0070] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application, and any equivalent structure or equivalent process conversion, or direct or indirect application in other related technical fields, which are made by using the content of the present application specification and drawings, are also included in the patent protection scope of the present application.

Claims

1. A mining spraying material with high solid waste content, characterized in that, The mining spraying material includes cement, mineral powder, stone chips, silica fume, zeolite powder, and wollastonite powder.

2. The mining spraying material according to claim 1, characterized in that, The amount of each component in the mining spraying material is as follows: cement 17%~28%, mineral powder 6%~17%, stone chips 60%~70%, silica fume 2%~6%, zeolite powder 0.5%~3.0% and wollastonite powder 0.5%~3.0%.

3. The mining spraying material according to claim 2, characterized in that, The amount of each component in the mining spraying material is as follows: cement 20%~25%, mineral powder 10%~15%, stone chips 65%~68%, silica fume 3%~5%, zeolite powder 1.0%~2.0% and wollastonite powder 1.0%~2.0%.

4. The mining spraying material according to claim 3, characterized in that, The amount of each component in the mining spraying material is as follows: cement 25%, mineral powder 6.0%, stone chips 65%, silica fume 2%, zeolite powder 1.0%, and wollastonite powder 1.0%.

5. A method for preparing a mining spraying material with high solid waste content, characterized in that, The method for preparing the mining spraying material according to any one of claims 1 to 4 includes: Weigh out the zeolite powder according to the mass fraction, and then grind it to obtain zeolite powder with a particle size of less than 3.64 μm; The zeolite powder is activated to obtain activated zeolite powder. Weigh out cement, mineral powder, stone chips, silica fume, and silica fume powder by weight, add them to a mixer, and mix them evenly after a preset mixing time to obtain a dry powder mixture. The activated zeolite powder is added to the dry powder mixture, and then water is added according to the preset water-to-material ratio. The mixture is stirred until homogeneous to obtain the high solid waste content mining spray material.

6. The preparation method according to claim 5, characterized in that, The activation process is achieved through the following method: The zeolite powder is calcined at a preset calcination temperature and for a preset calcination time. The calcined zeolite powder is soaked in an alkaline solution of preset concentration and temperature, and then dried after a preset soaking time.

7. The preparation method according to claim 5, characterized in that, The preset water-to-material ratio is 0.15~0.20:

1.

8. The preparation method according to claim 6, characterized in that, The preset roasting temperature is 260℃~350℃, and the preset roasting time is 0.5 h~1.0 h; the preset concentration is 1.0%~4.0%, the preset soaking temperature is 45℃~85℃, and the preset soaking time is 0.8 h~1.5 h.

9. The application of a mining spraying material with high solid waste content, characterized in that, The mining spraying material prepared by the preparation method according to any one of claims 5 to 8 is applied to underground operations.

10. The application according to claim 9, characterized in that, In the underground operation, the coating thickness of the mining spraying material is 2mm to 10mm, and after spraying, it is cured for 24h to 48h at a humidity of >80% and a temperature of 10℃ to 35℃.

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