Method for preparing gelling sound insulation material by foaming and mineralizing alkali-activated magnesium slag

Abstract

The invention relates to a method for preparing a gelling sound insulation material by foaming and mineralizing alkali-activated magnesium slag, and belongs to the technical field of resource utilization of industrial solid wastes. The preparation method comprises the following steps: mixing magnesium slag, water, an alkali activator, a functional activator, a foam stabilizer and a foaming agent to obtain homogeneous slurry, pouring, curing and forming, and demolding; and after demolding is finished, carrying out mineralization reaction to obtain the gelling sound insulation material. After alkali excitation and foaming treatment, the prepared gelling sound insulation material has certain strength and stability, the highest strength can reach 24.41 MPa, the sound insulation amount can reach 87.41 dB under the frequency of 6500 Hz, the sound absorption coefficient is 0.89, and excellent physical properties are shown. The method is simple in preparation process, mild in condition and easy to industrialize. According to the method, a new way, a new method and a new shortcut are discussed for fixing the carbon dioxide while the available way of the magnesium slag is expanded, and the purpose of treating waste with waste is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of resource utilization of industrial solid waste, and specifically relates to a method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization. Background Art

[0002] As the output of primary magnesium increases year by year, the demand for magnesium is also rising. However, with the rapid development of the magnesium industry, many environmental problems have arisen. At present, most magnesium plants use the Pijiang process to refine magnesium, which is energy-intensive, polluting, and emits a large amount of magnesium slag. These magnesium slags are mostly discarded as solid waste, which not only wastes land resources, but also affects air quality and human health due to the high content of fine powder. Therefore, how to reasonably and efficiently utilize magnesium slag has become a difficult problem that magnesium plants and even the whole society need to solve urgently.

[0003] Alkali-activated cementitious materials are materials with cementitious properties obtained by activating industrial waste slag with alkaline activators. Compared with silicate cement, their preparation has less pollution and lower energy consumption, and they can absorb a large amount of industrial solid waste. The dicalcium silicate in magnesium slag has a high reaction activity towards CO2 and can be used to adsorb mineralized carbon dioxide, which is of great significance for achieving efficient utilization of magnesium slag and alleviating environmental pollution.

[0004] The cementitious sound insulation material prepared by using magnesium slag through foaming alkali-activated mineralization makes full use of industrial solid waste magnesium slag, reduces waste slag accumulation, reduces environmental pollution, and realizes waste recycling. After alkali activation and foaming treatment, a cementitious material with certain strength and stability can be formed. The unique structure of this material makes it possible to have good sound insulation effect and can effectively block the propagation of sound. Compared with traditional materials, its production process may consume less energy. Studies have shown that the effect of using water glass and sodium hydroxide to activate magnesium slag can reach a maximum compressive strength of 17.79MPa in 28 days. Patent CN116283170 A discloses a foamed alkali-activated cementitious material and its preparation method. The author blends blast furnace slag, low-calcium fly ash, and alkaline magnesium slag, and adds excess aluminum powder and functional gel-like micro-nano TiO2 catalyst to prepare a gelled nano-photocatalyst. The author mixed blast furnace slag, low-calcium fly ash, and alkaline magnesium slag, and added excess aluminum powder and functional gel-like micro-nano TiO2 catalyst to prepare gelled nano photocatalyst. However, this process has some problems, such as being affected by micro-nano TiO2 catalyst, high material consumption, and unclear performance evaluation of the catalyst, all of which limit its application. In patent CN115215620A "A sound-absorbing foam concrete board using tailings sand and its preparation method", 52.5 grade silicate cement, tailings sand, admixtures, regulators, admixtures, water, foaming agents and waterproofing agents are mixed and stirred and then poured and demolded. However, in the pretreatment of raw materials, the admixtures need to be ground to more than 500 mesh, and the cement slurry on the surface of the demolded product needs to be cut off by a cutting machine. These treatments greatly increase the complexity of the experiment, resulting in high requirements for production equipment and processes for the implementation of this patent, which may limit its large-scale promotion and application.

[0005] In view of this, how to use magnesium slag to prepare a new type of high-strength open-pored sound-absorbing material is to solve the problem of limited application of existing cementitious sound insulation materials. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art such as complicated and cumbersome processes and high processing costs, and to provide a method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization. The present invention promotes the activity of magnesium slag by adding an alkaline solution, and utilizes foaming means to overcome the problem of incomplete and insufficient reaction with CO2 and the like under previous conditions, so that the magnesium slag can fully contact with CO2 and undergo a mineralization reaction, thereby achieving permanent fixation of carbon dioxide. The prepared sound insulation material contains a large number of open pores, and has good sound insulation and sound absorption effects, thereby promoting environmental sustainable development and effective utilization of resources. While expanding the available ways of magnesium slag, the present invention explores new ways, new methods, and new shortcuts to achieve the fixation of carbon dioxide, thereby achieving the purpose of "treating waste with waste."

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] On the one hand, the present invention provides a method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization, comprising the following steps:

[0009] Step 1: Mix magnesium slag, water, alkaline activator, functional activator, foaming agent and foam stabilizer to obtain a homogeneous slurry, and demould after pouring and curing;

[0010] Step 2: After demoulding, a mineralization reaction is performed to obtain the gelled sound insulation material.

[0011] Furthermore, the magnesium slag in step 1 includes the following components in percentage by mass: 30-40wt% SiO2, 0.5-3wt% Al2O3, 50-60wt% CaO, 1-10wt% Fe2O3, and 1-5wt% MgO.

[0012] Furthermore, in step 1, the alkaline activator is at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, water glass, and potassium silicate to activate the activity of the magnesium slag; and the amount of the alkaline activator added is 6-10wt% of the magnesium slag.

[0013] Furthermore, in step 1, the functional stimulant is at least one of potassium permanganate, potassium iodide and manganese dioxide to promote the foaming efficiency of the foaming agent and increase the volume expansion rate of the slurry; the added amount of the functional stimulant is 1 to 5 wt % of the foaming agent.

[0014] Furthermore, in step 1, the foaming agent is hydrogen peroxide or aluminum powder, and the amount of the foaming agent added is 5-10wt% of the magnesium slag.

[0015] Furthermore, in step 1, the foam stabilizer is at least one of calcium stearate, tea saponin, sodium dodecylbenzene sulfonate, hydroxypropyl methylcellulose ether, and polyacrylamide, and the amount of the foam stabilizer added is 5 to 10 wt % of the foaming agent.

[0016] Furthermore, the curing time in step 1 is 24 hours and the temperature is 60°C.

[0017] Furthermore, the conditions for the mineralization reaction in step 2 are: CO2 volume concentration ≥ 30%, CO2 pressure 0.4-2.0 MPa, temperature 120-200°C, and time 1-5 h.

[0018] Another aspect of the present invention provides a gelled sound insulation material, which is prepared by the method as described above.

[0019] Another aspect of the present invention provides the use of the above-mentioned gelled sound insulation material as a building material.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The gelled sound insulation material prepared by the present invention has certain strength and stability. 2+ Dissolution, [SiO4] 4- The polymer structure changes to form CSH gel, which provides support for the initial strength of the sound insulation material. After the CO2 mineralization reaction, the generated calcium carbonate further increases its compressive strength, up to 24.41MPa. 2+ It is easier to react with CO2, which further improves the mineralization efficiency.

[0022] (2) By changing the ratio of alkaline stimulant, functional stimulant, foaming agent and foam stabilizer, the pore structure is systematically regulated so that the pores are transformed from closed cells to open cells. This unique structure enables it to have excellent sound insulation effect and can effectively block the propagation of sound. It has excellent sound insulation performance in the high-frequency stage, especially at a frequency of 6500Hz, the sound insulation volume can reach 87.41dB and the sound absorption coefficient reaches 0.89.

[0023] (3) The present invention uses foaming alkali to stimulate mineralization and transform magnesium slag into gelled sound insulation material, making full use of industrial solid waste magnesium slag. This measure effectively reduces the accumulation of waste slag, alleviates environmental pollution, and achieves the goal of waste recycling.

[0024] (4) The preparation process of the gelled sound insulation material of the present invention is simple, the conditions are mild, and it is easy to realize industrialization. Compared with traditional materials, the energy consumption in the production process may be lower, and the high-value utilization of solid waste can be achieved, which is conducive to the recycling and sustainable development of resources. It has excellent environmental benefits and broad market prospects, and is a new technology with great potential for future development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the SEM image of the sample before and after mineralization in Example 1;

[0026] Figure 2 This is a graph of the sound insulation and sound absorption coefficient under optimal conditions, i.e., Example 7.

[0027] Figure 3 Surface images of the gelled sound insulation materials prepared in Example 1 and Example 9. DETAILED DESCRIPTION

[0028] In order to facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0029] Example 1

[0030] The naturally cooled magnesium slag from a magnesium smelting plant in Shaanxi was selected as the raw material, with a specific surface area of ​​324.7m 2 / kg, analyzed by XRF, and its chemical composition and weight percentage are shown in Table 1.

[0031] Table 1 Elemental composition of magnesium slag (wt. / %)

[0032]

[0033] The alkaline activator is a compound of sodium hydroxide and water glass. The water glass modulus is the ratio of the amount of substances of SiO2 to Na2O. The original water glass modulus is 3.3. The added alkaline activator is converted into Na2O according to the stoichiometric calculation, and the modulus is set to 1.0. The amount of the alkaline activator added is 8wt% of the magnesium slag; the foaming agent is H2O2, and its addition amount is 1wt% of the magnesium slag; the foam stabilizer is calcium stearate, and its addition amount is 1wt% of H2O2; the functional activator is MnO2, and its addition amount is 1wt% of H2O2.

[0034] According to calculation, 150g magnesium slag is mixed with 44.35g water, 44.8g water glass, 10.8g NaOH, 0.015g calcium stearate and 0.015g MnO2 are added, stirred at a speed of 1200r / min for 3min, and then 1.5g H2O2 is added and stirred at a speed of 2000r / min for 1min. The homogeneous slurry is poured into a silica gel mold, and the mold height is 1 / 3 to 1 / 2 of the mold depth. After vibrating for 30s, it is cured at 60℃ for 24h and then demolded. After demolding, it is sent to a carbonization reactor, and 0.4MPa and 40% CO2 are introduced. Carbonization curing is carried out at 180℃ for 2h to obtain a gelled sound insulation material.

[0035] Example 2

[0036] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that the added amount of the foam stabilizer is 5wt% of H2O2, and the added amount of the functional stimulant is 3wt% of H2O2.

[0037] Example 3

[0038] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that the added amount of the foam stabilizer is 10wt% of H2O2, and the added amount of the functional stimulant is 5wt% of H2O2.

[0039] Example 4

[0040] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that: the addition amount of the foaming agent H2O2 is 5wt% of the magnesium slag, the addition amount of the foam stabilizer is 1wt% of the H2O2, and the addition amount of the functional stimulant is 3wt% of the H2O2.

[0041] Example 5

[0042] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that: the addition amount of the foaming agent H2O2 is 5wt% of the magnesium slag, the addition amount of the foam stabilizer is 5wt% of the H2O2, and the addition amount of the functional stimulant is 5wt% of the H2O2.

[0043] Example 6

[0044] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that: the addition amount of the foaming agent H2O2 is 5wt% of the magnesium slag, the addition amount of the foam stabilizer is 10wt% of the H2O2, and the addition amount of the functional stimulant is 1wt% of the H2O2.

[0045] Example 7

[0046] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that the addition amount of the foaming agent H2O2 is 10wt% of the magnesium slag, the addition amount of the foam stabilizer is 1wt% of the H2O2, and the addition amount of the functional stimulant is 5wt% of the H2O2.

[0047] Example 8

[0048] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that: the addition amount of the foaming agent H2O2 is 10wt% of the magnesium slag, the addition amount of the foam stabilizer is 5wt% of the H2O2, and the addition amount of the functional stimulant is 1wt% of the H2O2.

[0049] Example 9

[0050] The preparation method of the gelled sound insulation material in this embodiment is basically the same as that in Embodiment 1, except that: the addition amount of the foaming agent H2O2 is 10wt% of the magnesium slag, the addition amount of the foam stabilizer is 10wt% of the H2O2, and the addition amount of the functional stimulant is 3wt% of the H2O2.

[0051] Table 2 shows the physical properties of the gelled sound insulation materials prepared in Examples 1 to 9. It is worth noting that the sound absorption coefficient and sound insulation volume measured at different frequencies are different. This experiment selected data at a high frequency of 6500 Hz.

[0052] Table 2 Physical properties of the gelled sound insulation materials prepared in Examples 1 to 9

[0053]

[0054] The above description is only for better explaining the embodiments of the present invention, and is not intended to limit the present invention. Any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall fall within the scope of the present invention.

Claims

1. A method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization, characterized in that: The following steps are involved: Step 1: Mix magnesium slag, water, alkaline activator, functional activator, foaming agent and foam stabilizer to obtain a homogeneous slurry, and demould after pouring, curing and forming; Step 2: After demoulding, a mineralization reaction is performed to obtain the gelled sound insulation material.

2. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: The magnesium slag in step 1 includes the following components in percentage by mass: 30-40wt% SiO2, 0.5-3wt% Al2O3, 50-60wt% CaO, 1-10wt% Fe2O3, and 1-5wt% MgO.

3. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: In step 1, the alkali activator is at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, water glass, and potassium silicate, and the amount of the alkali activator added is 6-10wt% of the magnesium slag.

4. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: In the step 1, the functional stimulant is at least one of potassium permanganate, potassium iodide and manganese dioxide, and the added amount of the functional stimulant is 1-5wt% of the foaming agent.

5. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: In step 1, the foaming agent is hydrogen peroxide or aluminum powder, and the amount of the foaming agent added is 5-10wt% of the magnesium slag.

6. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: In step 1, the foam stabilizer is at least one of calcium stearate, tea saponin, sodium dodecylbenzene sulfonate, hydroxypropyl methylcellulose ether, and polyacrylamide, and the amount of the foam stabilizer added is 5-10wt% of the foaming agent.

7. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: The curing time in step 1 is 24 hours and the temperature is 60°C.

8. The method for preparing a gelled sound insulation material by alkali-activated magnesium slag foaming mineralization according to claim 1, characterized in that: The conditions for the mineralization reaction in step 2 are: CO2 volume concentration ≥ 30%, CO2 pressure 0.4-2.0 MPa, temperature 120-200°C, and time 1-5 hours.

9. A gelled sound insulation material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. The use of the gelled sound insulation material according to claim 9, characterized in that: Used as building material.

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