Preparation method of modified quartz powder

Abstract

The invention relates to the technical field of quartz powder preparation, in particular to a preparation method of modified quartz powder. The preparation method of the modified quartz powder provided by the invention comprises the following steps: S1, adding a modifier and water into a quartz sand raw material by adopting a first pumping device and a second pumping device respectively to obtain a first mixture; s2, performing premixing treatment on the first mixture to obtain a second mixture; and S3, grinding the second mixture to obtain the modified quartz powder. The preparation method of the modified quartz powder has the advantages of good modification effect, high production efficiency, low energy consumption, good stability of the modification process, safety and no risk, and avoids the reduction and failure of the modification effect caused by long-time mixing of the modifier and water.

Description

Technical Field

[0001] The invention relates to the technical field of quartz powder preparation, and in particular to a method for preparing modified quartz powder. Background Art

[0002] At present, the preparation method of quartz powder is relatively simple. The quartz raw materials quartz sand and quartz coarse powder are conveyed to the front feed port of the horizontal ball mill through a belt. After the raw materials are ground by the ball mill, they are separated by negative pressure air at the rear discharge port. The ground powder is conveyed to the grading and screening process by negative pressure wind power. The powder that meets the requirements of fineness directly enters the finished product warehouse, and the powder that does not meet the requirements of fineness will enter the return pipe and continue to enter the ball mill for secondary grinding.

[0003] In many cases, it is not ideal to use quartz powder directly in organic quartz stone as an organic filler without modification. This is mainly because the surface of natural quartz powder is highly polar and has poor affinity with polymer materials. It is unevenly dispersed when used as a filler and easily agglomerates, which increases the resin dosage and causes local deviations in the quartz stone and resin content, greatly affecting the physical and chemical properties of the product.

[0004] Quartz powder modification technology can be mainly classified into two categories. One is to add modifiers to quartz powder under certain conditions, and obtain modified quartz powder through stirring, heating, etc.; the other is wet modification, that is, adding quartz powder to a specific modifier solution, and obtaining modified quartz powder through stirring, drying, grinding, etc. The above two processes are both modified with quartz powder as raw material. Quartz powder has low surface activity and a small number of active groups that can participate. Quartz powder modification requires heating and other specific conditions, and the required energy consumption is high. At the same time, the two processes require specific equipment and more complicated processes, with high equipment investment and low production efficiency.

[0005] The modifier of quartz powder in the prior art generally adopts silane coupling agent. For silane coupling agent, a binary solvent system of ethanol and water is mostly used, but there are the following problems: First, ethanol is a flammable and explosive chemical. In the industrial production of quartz powder, because the temperature in the ball mill is high, using ethanol as a solvent poses a safety risk. Second, the mixed solution of the prepared silane coupling agent, water and ethanol, due to the continuous hydrolysis and alcoholysis of the silane coupling agent and the continuous polymerization reaction to generate polymers, the activity continues to decrease and the steric hindrance continues to increase, resulting in the grafting reaction and adsorption with the surface of the quartz powder becoming increasingly difficult. As the storage time continues to increase, the modification effect gradually decreases or even fails.

[0006] In view of this, this invention is proposed. Summary of the invention

[0007] The object of the present invention is to provide a preparation method of modified quartz powder, which has good modification effect, high production efficiency, low energy consumption, good modification process stability, safety and no risk, and avoids the reduction of modification effect and failure caused by long-term mixing of the modifier and water.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] The present invention provides a method for preparing modified quartz powder, comprising the following steps:

[0010] S1, respectively using a first pumping device and a second pumping device to add a modifier and water to a quartz sand raw material to obtain a first mixture;

[0011] S2, pre-mixing the first mixed material to obtain a second mixed material;

[0012] S3. Grinding the second mixed material to obtain the modified quartz powder.

[0013] Furthermore, in step S1, the mass ratio of the modifier to the water is 1:(3-6).

[0014] Furthermore, in step S1, the mass of the modifier is 0.1% to 0.5% of the mass of the quartz sand raw material.

[0015] Furthermore, in step S1, the modifier includes a silane coupling agent.

[0016] Furthermore, in step S1, the quartz sand raw material includes one or more of quartz sand with a particle size of 26-40 mesh, quartz sand with a particle size of 40-70 mesh, quartz sand with a particle size of 70-120 mesh, and coarse quartz powder with a particle size of 120-200 mesh.

[0017] Furthermore, in step S1, the first pumping device and the second pumping device are used to pump the modifier and the water into the T-shaped porous tube respectively, and after mixing, the modifier and the water are added into the quartz sand raw material.

[0018] Furthermore, in step S2, the stirring method of the premixing process includes a spiral stirring method.

[0019] Furthermore, in step S2, the stirring rate of the premixing process is 20 to 50 r / min, and the time of the premixing process is 3 to 10 min.

[0020] Further, step S3 includes at least one of the following features (1) to (3);

[0021] (1) The grinding comprises ball milling;

[0022] (2) The ball milling temperature is 80-90° C.;

[0023] (3) The ball milling time is 5 to 30 minutes.

[0024] Furthermore, in step S3, the ball milling includes using a ball mill, and the ball mill is provided with a temperature control system.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The preparation method of the modified quartz powder provided by the present invention has simple steps, good modification effect, greatly reduces energy consumption, greatly improves production efficiency, is safe and risk-free, and avoids the reduction and failure of the modification effect caused by long-term mixing of the modifier and water; the prepared modified quartz powder has stable performance, low oil absorption value, good hydrophobicity, and can be used in resin quartz stone materials to effectively reduce the amount of resin used. DETAILED DESCRIPTION

[0027] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0028] The following is a detailed description of the preparation method of the modified quartz powder of the present invention.

[0029] In some embodiments of the present invention, a method for preparing modified quartz powder is provided, comprising the following steps:

[0030] S1, respectively using a first pumping device and a second pumping device to add a modifier and water to a quartz sand raw material to obtain a first mixture;

[0031] S2, pre-mixing the first mixed material to obtain a second mixed material;

[0032] S3. Grind the second mixed material to obtain modified quartz powder.

[0033] The preparation method of modified quartz powder provided by the present invention is to modify quartz powder in the process of grinding quartz powder with quartz sand to obtain modified quartz powder; the preparation method of modified quartz powder has simple steps, low investment, low cost, high efficiency, safety and environmental protection, and solves the problems of complex process, high cost, high equipment investment and low production efficiency in the existing preparation method of modified quartz powder.

[0034] The preparation method of the modified quartz powder provided by the present invention has greatly reduced energy consumption per ton and greatly improved production efficiency compared with the existing quartz powder modification process, and at the same time, the modification effect is more excellent. The prepared modified quartz powder has stable performance, low oil absorption value, good hydrophobicity, and can be used in resin quartz stone materials to effectively reduce the amount of resin used.

[0035] In the preparation method of the modified quartz powder of the present invention, only water is used as a diluent and a reaction medium, thereby improving safety performance.

[0036] In the preparation method of the modified quartz powder of the present invention, the modifier and water are fed separately in a double-dropping form, thereby avoiding the reduction of the modification effect and failure caused by the long-term mixing of the modifier and water.

[0037] In the preparation method of the modified quartz powder of the present invention, a premixing treatment step is added before grinding, so that the modification effect of the quartz powder is more uniform and stable, thereby improving the modification effect.

[0038] In some embodiments of the present invention, in step S1, the mass ratio of the modifier to water is 1:(3-6); typically but not limiting, for example, the mass ratio of the modifier to water can be 1:3, 1:4, 1:5, 1:6 or a range of any two thereof.

[0039] The mass ratio of the modifier to water of the present invention is within the above range, which is beneficial to improving the modification effect; when the modifier content is high and the water content is low, there is a problem of insufficient diluent and poor uniformity; when the modifier content is low and the water content is high, there is too much diluent, resulting in powder sticking to balls, occupying the wall, and uneven grinding.

[0040] In some embodiments of the present invention, in step S1, the mass of the modifier is 0.1% to 0.5% of the mass of the quartz sand raw material; typically but not limiting, for example, the mass of the modifier is 0.1%, 0.2%, 0.3%, 0.4%, 0.5% of the mass of the quartz sand raw material or a range of any two thereof.

[0041] In some embodiments of the present invention, in step S1, the modifier includes a silane coupling agent; preferably, the silane coupling agent includes at least one of KH560, KH550 and KH570.

[0042] In some specific embodiments of the present invention, in step S1, a first pumping device and a second pumping device are respectively used to add a silane coupling agent and water into a quartz sand raw material to obtain a first mixture.

[0043] The silane coupling agent used in the prior art mostly uses a binary solvent system of ethanol and water. Ethanol is a flammable and explosive chemical. It is used in the industrial production of quartz powder. Because the temperature in the mill is relatively high, between 60 and 100°C, using ethanol as a solvent poses a safety risk. The present invention only uses water as a diluent and reaction medium, and there is no safety risk.

[0044] The mixed solution of silane coupling agent, water and ethanol has a continuously hydrolyzed and alcoholyzed silane coupling agent and continuously undergoes polymerization reaction to generate high polymer, which leads to a continuously reduced activity and an increased steric hindrance, making it increasingly difficult to graft and adsorb on the surface of quartz powder. As the storage time increases, the modification effect gradually decreases or even fails. The present invention adopts a double drop feeding method of silane coupling agent and water, thereby avoiding the reduction and failure of the modification effect caused by the long-term mixing of silane coupling agent and water.

[0045] In some embodiments of the present invention, in step S1, the quartz sand raw material includes one or more of quartz sand with a particle size of 26-40 mesh, quartz sand with a particle size of 40-70 mesh, quartz sand with a particle size of 70-120 mesh, and coarse quartz powder with a particle size of 120-200 mesh.

[0046] In some embodiments of the present invention, in step S1, a first pumping device and a second pumping device are used to pump the modifier and water into the T-shaped porous tube respectively, and after mixing, they are added to the quartz sand raw material; preferably, the first pumping device and the second pumping device include metering pumps.

[0047] In some embodiments of the present invention, in step S2, the stirring method of the premixing treatment includes a spiral stirring method.

[0048] In some embodiments of the present invention, in step S2, the stirring rate of the premixing treatment is 20 to 50 r / min, and the time of the premixing treatment is 3 to 10 min; typically but not limitatively, for example, the stirring rate of the premixing treatment can be 20 r / min, 30 r / min, 40 r / min, 50 r / min or a range value consisting of any two thereof; the time of the premixing treatment can be 3 min, 5 min, 8 min, 10 min or a range value consisting of any two thereof.

[0049] In some embodiments of the present invention, in step S2, the premixing process includes using a premixer; the premixer is a continuous production method, using a spiral stirring method, feeding at one end, and discharging at the other end after spiral stirring.

[0050] In some embodiments of the present invention, in step S3, grinding includes ball milling.

[0051] The process of ball milling involves a variety of effects, such as physical effects, chemical effects, and mechanochemical effects, which can not only change the morphology, particle size, and structure of inorganic particles, such as particle refinement, grain refinement, cracking, density changes (apparent density, true density), and specific surface area, but also give the particle surface higher active points, which will release exo-excited electrons and activate polymers to participate in the reaction. Quartz sand will not only break the solid material under the action of the mechanical force of the ball mill, but also cause lattice defects, constantly generate new interfaces, increase the internal energy of the solid material, and cause the Si-O bond to break, and produce higher active points on the surface, making it in an unstable chemically active state, and easy to react with active monomers (modifiers).

[0052] In some embodiments of the present invention, in step S3, the temperature of ball milling is 80-90°C; typically but not limiting, for example, the temperature of ball milling can be 80°C, 82°C, 84°C, 86°C, 88°C, 90°C or a range of any two thereof.

[0053] In some embodiments of the present invention, in step S3, the ball milling time is 5 to 30 minutes; typically but not limitatively, for example, the ball milling time can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes or a range of any two thereof; the present invention does not strictly limit the ball milling time, and the ball milling time can be adjusted according to the desired particle size of the modified quartz powder. The longer the ball milling time, the smaller the particle size of the modified quartz powder. When the ball milling time is 6 to 10 minutes, a modified quartz powder with a particle size of about 325 mesh can be obtained.

[0054] In some embodiments of the present invention, in step S3, ball milling includes using a ball mill, and the ball mill is provided with a temperature control system; preferably, the temperature control system uses cold and hot air compensation to control the temperature in the ball mill cabin.

[0055] During the ball milling of quartz sand, the grinding balls in the ball mill continuously generate heat due to friction and impact. The temperature control system uses cold and hot air compensation to control the temperature in the ball mill cabin to be constant at 80-90°C, and the ball milling time is controlled at 6-10 minutes. Under this environment, the modifier can quickly undergo chemical grafting reaction and physical adsorption and wrapping with the surface of the quartz powder to complete the modification process.

[0056] The present invention performs ball milling at 80-90° C., which is beneficial to improving the modification effect; when the ball milling temperature is low, the reaction activity is low, and only part of the modifier participates in the modification reaction; when the ball milling temperature is high, a large amount of water and modifier volatilization occurs, a small amount of modifier participating in the reaction is present, and the modification conditions are destroyed, thereby resulting in a poor modification effect.

[0057] The temperature control system in the ball mill uses cold and hot air compensation to control the temperature in the ball mill cabin to be constant at 80-90°C, which can ensure that the modification process is carried out in a stable temperature environment, avoid differences in modification effects due to temperature fluctuations, and cause quality fluctuations in the modified powder, thereby affecting product performance.

[0058] In some embodiments of the present invention, in step S3, after the second mixed material is ground, it passes through a wind selection system to grade and screen the modified quartz powders of different mesh sizes to obtain a finished modified quartz powder.

[0059] Example 1

[0060] The method for preparing the modified quartz powder provided in this embodiment comprises the following steps:

[0061] S1. Two metering pumps are used to quantitatively pump modifier KH560 and water simultaneously. The modifier KH560 and water are mixed through a T-shaped porous tube and then dripped onto the surface of the quartz sand raw material on the conveyor belt to obtain a first mixture; wherein the mass ratio of the modifier KH560 to water is 1:4, the mass of the modifier KH560 accounts for 0.35% of the mass of the quartz sand raw material, and the quartz sand raw material includes quartz sand with a particle size of 40 to 70 meshes, quartz sand with a particle size of 70 to 120 meshes, and coarse quartz powder with a particle size of 120 to 200 meshes in a mass ratio of 4:4:2;

[0062] S2, the first mixture is conveyed to a premixer by a belt for premixing, the stirring rate of the premixing is 20-50r / min, the time is 3-10min, and the second mixture is obtained; the premixer is a continuous production method, adopts a spiral stirring method, feeds at one end, and discharges at the other end after spiral stirring;

[0063] S3. The second mixture is conveyed to the ball mill through a belt. The temperature control system uses cold and hot air compensation to control the temperature in the ball mill to be constant at 85°C. The ball milling time is 10 minutes. After screening by the air selection system, modified quartz powder with a particle size of 325 mesh is obtained.

[0064] Example 2

[0065] The preparation method of the modified quartz powder provided in this embodiment refers to that in Embodiment 1, except that in step S1, the modifier KH560 is replaced by the modifier KH550.

[0066] Example 3

[0067] The preparation method of the modified quartz powder provided in this embodiment refers to that in Embodiment 1, except that in step S1, the modifier KH560 is replaced by the modifier KH570.

[0068] Example 4

[0069] The preparation method of the modified quartz powder provided in this embodiment refers to Example 1, except that in step S1, the mass ratio of the modifier KH560 to water is 1:3, and the mass of the modifier KH560 accounts for 0.5% of the mass of the quartz sand raw material.

[0070] Example 5

[0071] The preparation method of the modified quartz powder provided in this embodiment refers to Example 1, except that in step S1, the mass ratio of the modifier KH560 to water is 1:6, and the mass of the modifier KH560 accounts for 0.1% of the mass of the quartz sand raw material.

[0072] Example 6

[0073] The preparation method of the modified quartz powder provided in this embodiment refers to that in Embodiment 1, except that, in step S3, the temperature in the ball mill chamber is controlled to be constant at 90° C., and the ball milling time is 6 min.

[0074] Comparative Example 1

[0075] The modified quartz powder is prepared by the preparation method in the patent with publication number CN108299666A, which specifically includes the following steps:

[0076] Silane coupling agent KH560 and anhydrous ethanol are mixed to obtain a modifier solution with a silane coupling agent KH560 concentration of 5wt% to 10wt%, and the modifier solution is evenly sprayed into quartz powder with a particle size of 325 meshes under stirring, the mass of the silane coupling agent KH560 in the modifier solution accounts for 1.5% to 2% of the mass of the quartz powder, and then dried at 60°C to obtain modified quartz powder.

[0077] Comparative Example 2

[0078] The modified quartz powder is prepared by the preparation method in the patent with publication number CN112011315A, which specifically includes the following steps:

[0079] 100 g of quartz powder with a particle size of 325 mesh was heated to 60°C, 2 g of ammonia water was added, and the mixture was stirred evenly at a rate of 500 r / min, and dried at 120°C for 5 h to obtain dried quartz powder; after the dried quartz powder was heated to 120°C, 0.5 g of silane coupling agent was added, and the silane coupling agent was KH570, and the mixture was stirred and reacted at a rate of 500 r / min for 1 h to obtain modified quartz powder.

[0080] Comparative Example 3

[0081] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, except that in step S1, the mass ratio of the modifier KH560 to water is 1:1.

[0082] Comparative Example 4

[0083] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, except that in step S1, the mass ratio of the modifier KH560 to water is 1:8.

[0084] Comparative Example 5

[0085] The preparation method of the modified quartz powder provided in this comparative example comprises the following steps:

[0086] S1. Two metering pumps are used to quantitatively pump modifier KH560 and water simultaneously. The modifier KH560 and water are mixed through a T-shaped porous tube and then dripped onto the surface of the quartz sand raw material on the conveyor belt to obtain a first mixture; wherein the mass ratio of the modifier KH560 to water is 1:4, the mass of the modifier KH560 accounts for 0.35% of the mass of the quartz sand raw material, and the quartz sand raw material includes quartz sand with a particle size of 40 to 70 meshes, quartz sand with a particle size of 70 to 120 meshes, and coarse quartz powder with a particle size of 120 to 200 meshes in a mass ratio of 3:3:2;

[0087] S2. The first mixed material is conveyed to the ball mill by a belt. The temperature control system uses cold and hot air compensation to control the temperature in the ball mill to be constant at 85°C. The ball milling time is 10 minutes. After screening by the air selection system, modified quartz powder with a particle size of 325 mesh is obtained.

[0088] Comparative Example 6

[0089] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, the only difference being that in step S3, the temperature in the ball mill chamber is controlled to be 40°C.

[0090] Comparative Example 7

[0091] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, the only difference being that in step S3, the temperature in the ball mill chamber is controlled to be 100°C.

[0092] Comparative Example 8

[0093] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, except that in step S1, the modifier KH560 and water are mixed in a mass ratio of 1:4, mixed for 1 hour, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0094] Comparative Example 9

[0095] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, except that in step S1, the modifier KH560 and water are mixed in a mass ratio of 1:4, mixed for 2 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0096] Comparative Example 10

[0097] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, except that in step S1, the modifier KH560 and water are mixed in a mass ratio of 1:4, mixed for 4 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0098] Comparative Example 11

[0099] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, with the only difference being that in step S1, the modifier KH560 and water are mixed in a mass ratio of 1:4, mixed for 6 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0100] Comparative Example 12

[0101] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, with the only difference being that in step S1, the modifier KH560 and water are mixed in a mass ratio of 1:4, mixed for 8 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0102] Comparative Example 13

[0103] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, with the only difference being that in step S1, the modifier KH560, water and ethanol are mixed in a mass ratio of 1:2:2, mixed for 4 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0104] Comparative Example 14

[0105] The preparation method of the modified quartz powder provided in this comparative example refers to Example 1, with the only difference being that in step S1, the modifier KH560, water and ethanol are mixed in a mass ratio of 1:2:2, mixed for 8 hours, and then pumped by a single metering pump and dripped onto the surface of the quartz sand raw material on the conveyor belt through a T-shaped porous tube.

[0106] Test example

[0107] The test method of oil absorption value: weigh the sample and place it on a clean glass plate with an area of ​​not less than 200mm×200mm, then use an acid burette with precision of Class A to load the oil (unsaturated polyester resin); use the acid burette to slowly drip the oil into the sample while constantly stirring with a glass rod so that the sample and oil are evenly mixed; the detection end point is: when the last drop is added, the sample and the oil just stick together into a ball, and there is no free dry sample. The calculation formula of oil absorption value is: A0=V / M(mL / g); where A0 is the oil absorption value; V is the volume of the oil used; M is the mass of the sample.

[0108] Contact angle test method: Take the sample and press it into a round pancake, then place it on a contact angle tester for hydrophilic angle test.

[0109] Test method for resin dosage: The formula of quartz powder fine particle board is used for determination. The material ratio of sand and powder of quartz powder fine particle board is as follows: quartz sand with a particle size of 40-70 mesh, quartz sand with a particle size of 70-120 mesh and quartz powder sample (325 mesh quartz powder or 325 mesh modified quartz powder) in a mass ratio of 4:3:3; when testing the resin dosage, weigh the materials according to the above ratio, put them in a mixer, add unsaturated polyester resin while stirring, until the material state can be pressed into shape, the curing agent dosage is 1% of the unsaturated polyester resin dosage, and the mass of the unsaturated polyester resin at this time divided by the total mass of the material is the required resin dosage.

[0110] Calculation method of energy consumption per ton of modified quartz powder: Example 1: Modified quartz powder is prepared by a ball mill, and ball milling one ton of modified quartz powder requires 72 kwh of energy; Comparative Example 1: The material is heated to 60°C for modification, and the required energy consumption is 46.5 kwh, and the energy consumption for preparing 1 ton of modified quartz powder is 118.5 kwh; Comparative Example 2: The material is heated to 110-160°C, and the required energy consumption is 140.1 kwh, and the energy consumption for preparing 1 ton of modified quartz powder is 212.1 kwh.

[0111] Calculation method of production efficiency: Example 1: It takes 10 minutes to prepare one ton of modified quartz powder by ball mill; Comparative Example 2: It takes 20 minutes to prepare one ton of modified quartz powder; Comparative Example 2: It takes 30 minutes to prepare one ton of modified quartz powder.

[0112] The energy consumption per ton of modified quartz powder and the production efficiency of the preparation methods of Example 1, Comparative Example 1 and Comparative Example 2 are recorded in Table 1; the properties of the modified quartz powder prepared in Example 1, Comparative Example 1 and Comparative Example 2 and the unmodified quartz powder are tested, and the results are shown in Table 1.

[0113] Table 1

[0114]

[0115]

[0116] It can be seen from Table 1 that, compared with the existing quartz powder modification process, the energy consumption per ton of the preparation method of the modified quartz powder of the present invention is greatly reduced, the production efficiency is greatly improved, and the modification effect is more superior.

[0117] Samples of modified quartz powder obtained in different batches of Example 1 and Comparative Examples 3 to 5 were respectively taken for performance testing, and the results are shown in Table 2.

[0118] Table 2

[0119]

[0120] As can be seen from Table 2, when the mass ratio of modifier to water is higher than 1 / 3, there is insufficient diluent and uneven uniformity. When the mass ratio of modifier to water is less than 1 / 6, there is too much diluent, resulting in powder sticking to balls, wall occupation and uneven grinding.

[0121] In the pre-mixing method, the modification effect of quartz powder is uniform and stable; in the case of no pre-mixing, the modification effect is unstable.

[0122] The properties of the modified quartz powders obtained in Examples 1 to 3 and Comparative Examples 6 to 7 were tested, and the results are shown in Table 3.

[0123] Table 3

[0124] Oil absorption value (%) Contact angle (°) Resin dosage (%) Example 1 22.5 146 11.0 Example 2 22.4 143 11.0 Example 3 22.6 148 11.0 Example 4 22.3 149 10.9 Example 5 22.8 140 11.2 Example 6 22.5 146 11.0 Comparative Example 6 26.5 98 11.9 Comparative Example 7 24.6 113 11.55

[0125] It can be seen from Table 3 that the three silane coupling agents KH550, KH560 and KH570 can have better modification effects on quartz powder by using the preparation method of modified quartz powder of the present invention.

[0126] The present invention has good modification effect when ball milling is performed within the temperature range of 80 to 90° C. for 6 to 10 minutes, and has little influence on the modification effect; wherein, the values ​​of the oil absorption value and the amount of resin used are taken to one decimal place, the contact angle is an integer, and the values ​​of the oil absorption value, the contact angle and the amount of resin used in Example 1 and Example 6 are the same; ball milling at 80 to 90° C. is beneficial to improving the modification effect; the ball milling temperature is relatively low, and the modification effect at 40° C. is only half of that at 80° C., the reaction activity is low, and only part of the modifier participates in the modification reaction; the ball milling temperature is relatively high, and at 100° C., the temperature is too high, resulting in a large amount of water and modifier volatilization, a small amount of modifier participating in the reaction, and the modification conditions are destroyed; thereby resulting in a poor modification effect.

[0127] Table 4

[0128]

[0129]

[0130] It can be seen from Table 4 that after the silane coupling agent is mixed with water, the modification effect gradually deteriorates with the extension of storage time. When the mixing time exceeds 8h, the modification effect of the silane coupling agent is basically ineffective.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing modified quartz powder, characterized in that: The steps include: S1, respectively using a first pumping device and a second pumping device to add a modifier and water to a quartz sand raw material to obtain a first mixture; S2, pre-mixing the first mixed material to obtain a second mixed material; S3. Grinding the second mixed material to obtain the modified quartz powder.

2. The method for preparing modified quartz powder according to claim 1, characterized in that: In step S1, the mass ratio of the modifier to the water is 1:(3-6).

3. The method for preparing modified quartz powder according to claim 2, characterized in that: In step S1, the mass of the modifier is 0.1% to 0.5% of the mass of the quartz sand raw material.

4. The method for preparing modified quartz powder according to claim 3, characterized in that: In step S1, the modifier includes a silane coupling agent.

5. The method for preparing modified quartz powder according to claim 3, characterized in that: In step S1, the quartz sand raw material includes one or more of quartz sand with a particle size of 26 to 40 meshes, quartz sand with a particle size of 40 to 70 meshes, quartz sand with a particle size of 70 to 120 meshes, and coarse quartz powder with a particle size of 120 to 200 meshes.

6. The method for preparing modified quartz powder according to claim 5, characterized in that: In step S1, the first pumping device and the second pumping device are used to pump the modifier and the water into the T-shaped porous tube respectively, and after mixing, the modifier and the water are added into the quartz sand raw material.

7. The method for preparing modified quartz powder according to claim 6, characterized in that: In step S2, the stirring method of the premixing process includes a spiral stirring method.

8. The method for preparing modified quartz powder according to claim 7, characterized in that: In step S2, the stirring rate of the premixing process is 20 to 50 r / min, and the time of the premixing process is 3 to 10 min.

9. The method for preparing modified quartz powder according to claim 8, characterized in that: In step S3, at least one of the following features (1) to (3) is included; (1) The grinding comprises ball milling; (2) The ball milling temperature is 80-90° C.; (3) The ball milling time is 5 to 30 minutes.

10. The method for preparing modified quartz powder according to claim 9, characterized in that: In step S3, the ball milling includes using a ball mill, and the ball mill is provided with a temperature control system.

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