Preparation method of quick-dry mortar based on aluminum hydroxide

Abstract

The invention discloses a preparation method of quick-dry mortar based on aluminum hydroxide, and relates to the technical field of mortar preparation, and the preparation method of the quick-dry mortar comprises the steps of raw material preparation, river sand pretreatment, aluminum hydroxide pretreatment, mixing and stirring, auxiliary reagent addition and packaging. The method has the advantages that efficient crushing, dispersion and surface modification of aluminum hydroxide powder particles are realized by adopting an airflow crushing and dispersing method in combination with a spray drying tower and a silane coupling agent surface modification treatment mode, and the method not only remarkably improves the dispersity of the aluminum hydroxide powder and the interface bonding force with a cement matrix, but also improves the strength of the aluminum hydroxide powder. The distribution uniformity of the aluminum hydroxide in the mortar is optimized, so that the overall mechanical property, durability and impermeability of the mortar are enhanced, the aluminum hydroxide is pretreated by utilizing an airflow crushing and dispersing method, particles of the aluminum hydroxide are crushed and dispersed more uniformly, and the agglomeration phenomenon of the aluminum hydroxide in the mortar is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of mortar preparation, and in particular to a preparation method of quick-drying mortar based on aluminum hydroxide. Background Art

[0002] In the field of building materials, quick-drying mortar is an important building material, which is widely used in various construction projects due to its advantages such as fast curing, convenient construction, high strength and good durability. In the traditional preparation process of quick-drying mortar, aluminum hydroxide is an important additive that can significantly improve the fire resistance, impermeability and chemical stability of the mortar. However, the dispersibility of aluminum hydroxide powder in mortar and the interfacial bonding strength with cement matrix have always been the key factors restricting its performance improvement.

[0003] Traditional methods of processing aluminum hydroxide powder mostly use simple mechanical grinding or ball milling. Although these methods can reduce the particle size of aluminum hydroxide particles to a certain extent, they often have problems such as uneven dispersion and easy agglomeration, which leads to uneven distribution of aluminum hydroxide in the mortar, thereby affecting the overall mechanical properties, durability and impermeability of the mortar. To this end, we propose a preparation method for quick-drying mortar based on aluminum hydroxide. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing quick-drying mortar based on aluminum hydroxide.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solution: a preparation method of quick-drying mortar based on aluminum hydroxide, comprising the following steps:

[0006] Step 1: Prepare raw materials: cement, aluminum hydroxide, river sand, redispersible latex powder, water reducing agent and cellulose ether;

[0007] Step 2: Pre-treat the river sand by placing the river sand in a spiral sand washer for cleaning, sending the cleaned river sand to a dryer for drying, and sending the dried river sand to a magnetic separation device to remove metal impurity particles;

[0008] Step 3: pre-treating aluminum hydroxide by using compressed air to crush and disperse aluminum hydroxide powder particles;

[0009] Step 4: Mixing and stirring: adding the pretreated river sand, cement and aluminum hydroxide into the mixer in sequence and stirring;

[0010] Step 5: Add auxiliary reagents, add the redispersible latex powder, water reducing agent and cellulose ether into the mixer in sequence and stir;

[0011] Step six: Packaging: bag the quick-drying mortar using a bagging machine.

[0012] As a further solution of the present invention: in step 1, the raw materials are prepared specifically by preparing 30-40 parts of cement, 10-20 parts of aluminum hydroxide, 30-45 parts of river sand, 2-5 parts of redispersible latex powder, 0.5-1.5 parts of water reducing agent and 0.1-0.3 parts of cellulose ether.

[0013] As a further solution of the present invention: In the step 2, the specific method of river sand pretreatment is to place the river sand into a spiral sand washing machine for cleaning for 20 minutes to 30 minutes, send the cleaned river sand into a dryer for drying for 30 minutes to 40 minutes, and control the drying temperature at 100°C to 120°C. The dried river sand is placed in a permanent magnetic drum magnetic separator to remove residual metal impurity particles.

[0014] As a further scheme of the present invention: In the step three, the specific method of pretreating aluminum hydroxide is to feed the aluminum hydroxide powder into the grinding chamber of the air flow mill through a feeding device, and use 0.4MPa-0.8MPa compressed air to grind and disperse the aluminum hydroxide powder particles in a high-speed airflow of 30m / s-100m / s.

[0015] As a further scheme of the present invention: in the step three, after the aluminum hydroxide is pretreated, the aluminum hydroxide powder treated by the air flow crushing dispersion method is placed at the feed inlet of the spray drying tower, and the silane coupling agent is weighed at a mass ratio of 1%-5% based on the mass of the aluminum hydroxide and dissolved in a 70%-95% concentration of ethanol solution to prepare a coupling agent solution, and the mass volume ratio of the silane coupling agent to the ethanol solution is 1:5.

[0016] As a further solution of the present invention: in the step three, after the coupling agent solution is prepared, a spray device is used to evenly spray the coupling agent solution in a mist form on the aluminum hydroxide powder continuously entering the spray drying tower, and then the aluminum hydroxide powder attached with the coupling agent solution is quickly dried by hot air at 100°C-150°C in the spray drying tower.

[0017] As a further scheme of the present invention: In the step 4, the specific method of mixing and stirring is to first feed the pretreated river sand into the mixer, stir at 10rpm-15rpm for 3min-5min, add cement, stir at 20rpm-30rpm for 5min-7min, add the treated aluminum hydroxide powder, and continue stirring for 3min-5min.

[0018] As a further scheme of the present invention: in the step five, the specific method of adding the auxiliary agent is to slowly add the redispersible latex powder into the mixer while stirring at 10rpm-15rpm, stir for 2min-3min, then add the water reducer, stir at 15rpm-20rpm for 2min-3min, add the cellulose ether, stir for 2min-3min, and while adding the cellulose ether, evenly spray the atomized nano titanium dioxide aqueous solution into the mixer through a spray device, and the added amount is 0.5%-1% of the total mass of the mortar.

[0019] As a further solution of the present invention: In the step six, the specific method of packaging is to bag the quick-drying mortar through a bagging machine to make bagged quick-drying mortar based on aluminum hydroxide, and place the bagged mortar on a vibration platform and vibrate for 5 minutes to 10 minutes.

[0020] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The present invention realizes efficient crushing, dispersion and surface modification of aluminum hydroxide powder particles by adopting a gas flow crushing and dispersion method combined with a spray drying tower and a silane coupling agent surface modification treatment method. This method not only significantly improves the dispersibility of aluminum hydroxide powder and the interfacial adhesion with the cement matrix, but also optimizes the distribution uniformity of aluminum hydroxide in the mortar, thereby enhancing the overall mechanical properties, durability and impermeability of the mortar;

[0022] 2. The present invention pre-treats aluminum hydroxide by using an airflow crushing and dispersion method, so that its particles are crushed and dispersed more evenly, which not only prevents the agglomeration of aluminum hydroxide in the mortar and ensures the uniformity of mixing of various components of the mortar, but also facilitates the uniform chemical reaction of aluminum hydroxide in the mortar, further improves the quick-drying performance of the mortar and the consistency of the overall performance, and reduces the performance instability problem caused by local component differences;

[0023] 3. The present invention improves the water resistance of the mortar by using redispersible latex powder, water reducing agent and cellulose ether auxiliary reagents, introduces nano titanium dioxide aqueous solution, and evenly sprays it into the mortar through a spray device, thereby improving the strength and durability of the mortar. At the same time, the uniform distribution of nano titanium dioxide helps to reduce the pores and defects inside the mortar, further improving its overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the steps of the method for preparing mortar in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in 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.

[0026] Embodiment 1:

[0027] Please see attached Figure 1 The present invention provides a method for preparing quick-drying mortar based on aluminum hydroxide, comprising the following steps:

[0028] Step 1: Prepare raw materials: cement, aluminum hydroxide, river sand, redispersible latex powder, water reducing agent and cellulose ether;

[0029] Step 2: Pre-treat the river sand by placing the river sand in a spiral sand washer for cleaning, sending the cleaned river sand to a dryer for drying, and sending the dried river sand to a magnetic separation device to remove metal impurity particles;

[0030] Step 3: pre-treating aluminum hydroxide by using compressed air to crush and disperse aluminum hydroxide powder particles;

[0031] Step 4: Mixing and stirring: adding the pretreated river sand, cement and aluminum hydroxide into the mixer in sequence and stirring;

[0032] Step 5: Add auxiliary reagents, add the redispersible latex powder, water reducing agent and cellulose ether into the mixer in sequence and stir;

[0033] Step 6: Packaging: pack the quick-drying mortar into bags using a bagging machine;

[0034] In step 1, the raw materials are prepared specifically as follows: 30-40 parts of cement, 10-20 parts of aluminum hydroxide, 30-45 parts of river sand, 2-5 parts of redispersible latex powder, 0.5-1.5 parts of water reducing agent and 0.1-0.3 parts of cellulose ether;

[0035] In step 2, the specific method of river sand pretreatment is to place the river sand in a spiral sand washing machine for cleaning for 20 minutes to 30 minutes, send the cleaned river sand into a dryer for drying for 30 minutes to 40 minutes, control the drying temperature at 100°C to 120°C, and place the dried river sand into a permanent magnetic drum magnetic separator to remove residual metal impurity particles.

[0036] Specific work flow: 35 parts of cement, 15 parts of aluminum hydroxide, 40 parts of river sand, 3 parts of redispersible latex powder, 1 part of water reducing agent and 0.2 parts of cellulose ether were selected as raw materials to prepare mortar;

[0037] Pretreatment of river sand: put the river sand into the spiral sand washer for 25 minutes, then send it into the dryer for 35 minutes. The drying temperature is controlled at 110℃. The dried river sand is passed through a permanent magnetic drum magnetic separator to remove residual metal impurity particles.

[0038] Aluminum hydroxide pretreatment, feeding aluminum hydroxide powder into the grinding chamber of the airflow mill through a feeding device, using 0.6MPa compressed air to grind and disperse aluminum hydroxide powder particles in a high-speed airflow of 60m / s, then placing the aluminum hydroxide powder treated by the airflow grinding and dispersion method at the feed port of a spray drying tower, weighing a silane coupling agent at a mass ratio of 3% and dissolving it in an 80% concentration ethanol solution (the mass volume ratio of the silane coupling agent to the ethanol solution is 1:5) to prepare a coupling agent solution, using a spray device to evenly spray the coupling agent solution in a mist form on the aluminum hydroxide powder continuously entering the spray drying tower, and then quickly drying the aluminum hydroxide powder attached with the coupling agent solution by hot air at 120°C in the spray drying tower;

[0039] Mixing and stirring: first feed the pre-treated river sand into the mixer, stir at 12rpm for 4min, add cement, stir at 25rpm for 6min, add the treated aluminum hydroxide powder, and continue stirring for 4min.

[0040] Add auxiliary reagents, slowly add the redispersible latex powder into the mixer at 12 rpm, stir for 2.5 min, then add the water reducer, stir for 2.5 min at 18 rpm, add cellulose ether, stir for 2.5 min, while adding cellulose ether, evenly spray atomized nano titanium dioxide aqueous solution into the mixer through a spray device, the addition amount is 0.8% of the total mass of the mortar;

[0041] Packaging: bagging the quick-drying mortar into bagged quick-drying mortar based on aluminum hydroxide by a bagging machine, and placing the bagged mortar on a vibration platform for vibration for 8 minutes;

[0042] The prepared mortar was performance tested. The mortar without aluminum hydroxide pretreatment and surface modification had a 28-day compressive strength of 25 MPa and a seepage pressure reduction of 0.4 MPa. The mortar treated with this embodiment had a 28-day compressive strength of 35 MPa and a seepage pressure reduction of 0.8 MPa. After being placed in a simulated harsh environment (high humidity and high salinity) for 90 days, there was no obvious change in appearance, while the comparison mortar showed surface peeling and decreased strength.

[0043] Furthermore, by adopting the air flow crushing and dispersion method combined with the spray drying tower and the surface modification treatment of the silane coupling agent, the efficient crushing, dispersion and surface modification of the aluminum hydroxide powder particles were achieved. This method not only significantly improved the dispersibility of the aluminum hydroxide powder and the interfacial adhesion with the cement matrix, but also optimized the uniformity of the distribution of aluminum hydroxide in the mortar, thereby enhancing the overall mechanical properties, durability and impermeability of the mortar.

[0044] Embodiment 2:

[0045] Based on Example 1, in step 3, the specific method of aluminum hydroxide pretreatment is to feed the aluminum hydroxide powder into the grinding chamber of the air flow mill through the feeding device, and use 0.4MPa-0.8MPa compressed air to grind and disperse the aluminum hydroxide powder particles in a high-speed airflow of 30m / s-100m / s;

[0046] In step 3, after aluminum hydroxide is pretreated, the aluminum hydroxide powder treated by air flow pulverization dispersion method is placed at the feed inlet of the spray drying tower, and a silane coupling agent is weighed at a mass ratio of 1%-5% according to the mass of aluminum hydroxide and dissolved in a 70%-95% concentration ethanol solution to prepare a coupling agent solution, and the mass volume ratio of the silane coupling agent to the ethanol solution is 1:5;

[0047] In step 3, after the coupling agent solution is prepared, the coupling agent solution is evenly sprayed on the aluminum hydroxide powder continuously entering the spray drying tower by a spray device, and then the aluminum hydroxide powder attached with the coupling agent solution is quickly dried by hot air at 100° C.-150° C. in the spray drying tower;

[0048] In step 4, the specific method of mixing and stirring is to first feed the pretreated river sand into the mixer, stir at 10rpm-15rpm for 3min-5min, add cement, stir at 20rpm-30rpm for 5min-7min, add the treated aluminum hydroxide powder, and continue stirring for 3min-5min.

[0049] Specific work flow: Use the raw material ratio of 32 parts of cement, 18 parts of aluminum hydroxide, 38 parts of river sand, 4 parts of redispersible latex powder, 1.2 parts of water reducing agent and 0.15 parts of cellulose ether;

[0050] The river sand pretreatment step is the same as in Example 1. The aluminum hydroxide pretreatment is performed by only using the airflow crushing and dispersion method. The aluminum hydroxide powder is fed into the crushing chamber of the airflow crusher through the feeding device, and the aluminum hydroxide powder particles are crushed and dispersed in the high-speed airflow of 80m / s using 0.5MPa compressed air;

[0051] The subsequent mixing, stirring, adding auxiliary reagents and packaging steps are the same as those in Example 1;

[0052] A quick-drying performance comparison test was conducted on the mortar and the mortar prepared by ordinary stirring method with aluminum hydroxide (without air flow crushing and dispersion). Under the same environmental conditions (temperature 25°C, relative humidity 60%), the initial setting time of the mortar prepared by ordinary stirring method was 180 min, and the final setting time was 360 min, while the initial setting time of the mortar prepared in this embodiment was shortened to 90 min, and the final setting time was 210 min.

[0053] Furthermore, by pre-treating aluminum hydroxide using the air flow crushing and dispersion method, its particles are crushed and dispersed more evenly, which not only prevents the agglomeration of aluminum hydroxide in the mortar and ensures the uniform mixing of the various components of the mortar, but also facilitates the uniform chemical reaction of aluminum hydroxide in the mortar, further improving the quick-drying performance of the mortar and the consistency of the overall performance, and reducing the performance instability problem caused by local component differences.

[0054] Embodiment three:

[0055] Based on Example 2, in step 5, the specific method of adding the auxiliary agent is to slowly add the redispersible latex powder into the mixer under stirring at 10rpm-15rpm, stir for 2min-3min, then add the water reducer, stir for 2min-3min at 15rpm-20rpm, add the cellulose ether, stir for 2min-3min, and while adding the cellulose ether, evenly spray the atomized nano titanium dioxide aqueous solution into the mixer through the spray device, and the addition amount is 0.5%-1% of the total mass of the mortar;

[0056] In step six, the specific packaging method is to bag the quick-drying mortar through a bagging machine to make bagged quick-drying mortar based on aluminum hydroxide, and place the bagged mortar on a vibration platform to vibrate for 5 minutes to 10 minutes.

[0057] Specific work flow: Raw material preparation, 38 parts of cement, 12 parts of aluminum hydroxide, 42 parts of river sand, 2.5 parts of redispersible latex powder, 0.8 parts of water reducing agent and 0.25 parts of cellulose ether;

[0058] River sand pretreatment was carried out according to conventional operations;

[0059] Aluminum hydroxide pretreatment was performed by conventional grinding (no air flow milling dispersion method was used);

[0060] Mixing and stirring: first feed the pretreated river sand into the mixer, stir at 13 rpm for 3.5 min, add cement, stir at 22 rpm for 5.5 min, add aluminum hydroxide powder, and continue stirring for 3.5 min;

[0061] Add auxiliary reagents, slowly add the redispersible latex powder into the mixer at 13 rpm, stir for 2.2 min, then add the water reducer, stir for 2.2 min at 16 rpm, add cellulose ether, stir for 2.2 min, while adding cellulose ether, evenly spray atomized nano titanium dioxide aqueous solution into the mixer through a spray device, the addition amount is 0.6% of the total mass of the mortar;

[0062] The packaging steps remain unchanged;

[0063] The mortar was tested for its performance, and its 7-day flexural strength was 6 MPa. The 7-day flexural strength of the mortar without adding nano-titanium dioxide aqueous solution and without optimizing the order of adding auxiliary reagents was 4.5 MPa. After 180 days of exposure to the natural environment, the strength retention rate of the mortar in this embodiment was 90%, while the strength retention rate of the comparison mortar was only 70%.

[0064] Furthermore, by using redispersible latex powder, water reducing agent and cellulose ether auxiliary agents to improve the water resistance of the mortar, introducing nano titanium dioxide aqueous solution and spraying it evenly in the mortar through a spray device, the strength and durability of the mortar are improved. At the same time, the uniform distribution of nano titanium dioxide helps to reduce the pores and defects inside the mortar, further improving its overall performance.

[0065] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing quick-drying mortar based on aluminum hydroxide, characterized in that: The following steps are involved: Step 1: Prepare raw materials: cement, aluminum hydroxide, river sand, redispersible latex powder, water reducing agent and cellulose ether; Step 2: Pre-treat the river sand by placing the river sand in a spiral sand washer for cleaning, sending the cleaned river sand to a dryer for drying, and sending the dried river sand to a magnetic separation device to remove metal impurity particles; Step 3: pre-treating aluminum hydroxide by using compressed air to crush and disperse aluminum hydroxide powder particles; Step 4: Mixing and stirring: adding the pretreated river sand, cement and aluminum hydroxide into the mixer in sequence and stirring; Step 5: Add auxiliary reagents, add the redispersible latex powder, water reducing agent and cellulose ether into the mixer in sequence and stir; Step six: Packaging: bag the quick-drying mortar using a bagging machine.

2. A method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step 1, the raw materials are prepared specifically as follows: 30-40 parts of cement, 10-20 parts of aluminum hydroxide, 30-45 parts of river sand, 2-5 parts of redispersible latex powder, 0.5-1.5 parts of water reducing agent and 0.1-0.3 parts of cellulose ether.

3. A method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step 2, the specific method of river sand pretreatment is to place the river sand into a spiral sand washing machine for cleaning for 20 minutes to 30 minutes, send the cleaned river sand into a dryer for drying for 30 minutes to 40 minutes, control the drying temperature at 100°C to 120°C, and place the dried river sand into a permanent magnetic drum magnetic separator to remove residual metal impurity particles.

4. A method for preparing quick-drying mortar based on aluminum hydroxide according to claim 3, characterized in that: In the step three, the specific method of aluminum hydroxide pretreatment is to feed the aluminum hydroxide powder into the grinding chamber of the air flow mill through the feeding device, and use 0.4MPa-0.8MPa compressed air to grind and disperse the aluminum hydroxide powder particles in a high-speed airflow of 30m / s-100m / s.

5. The method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step three, after the aluminum hydroxide is pretreated, the aluminum hydroxide powder treated by the air flow crushing dispersion method is placed at the feed inlet of the spray drying tower, and the silane coupling agent is weighed at a mass ratio of 1%-5% according to the mass of the aluminum hydroxide and dissolved in a 70%-95% concentration ethanol solution to prepare a coupling agent solution, and the mass volume ratio of the silane coupling agent to the ethanol solution is 1:

5.

6. A method for preparing quick-drying mortar based on aluminum hydroxide according to claim 5, characterized in that: In the step three, after the coupling agent solution is prepared, the coupling agent solution is evenly sprayed in a mist form on the aluminum hydroxide powder continuously entering the spray drying tower using a spray device, and then the aluminum hydroxide powder attached with the coupling agent solution is quickly dried by hot air at 100° C.-150° C. in the spray drying tower.

7. The method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step 4, the specific method of mixing and stirring is to first feed the pretreated river sand into the mixer, stir at 10rpm-15rpm for 3min-5min, add cement, stir at 20rpm-30rpm for 5min-7min, add the treated aluminum hydroxide powder, and continue stirring for 3min-5min.

8. The method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step 5, the specific method of adding auxiliary reagents is to slowly add the redispersible latex powder into the mixer while stirring at 10rpm-15rpm, stir for 2min-3min, then add the water reducer, stir at 15rpm-20rpm for 2min-3min, add cellulose ether, stir for 2min-3min, and while adding cellulose ether, evenly spray atomized nano titanium dioxide aqueous solution into the mixer through a spray device, and the added amount is 0.5%-1% of the total mass of the mortar.

9. The method for preparing quick-drying mortar based on aluminum hydroxide according to claim 1, characterized in that: In the step six, the specific packaging method is to bag the quick-drying mortar by a bagging machine to make bagged quick-drying mortar based on aluminum hydroxide, and place the bagged mortar on a vibration platform and vibrate for 5 minutes to 10 minutes.

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