Preparation method of calcium-magnesium mineral concrete artificial coral reef
By using natural calcium-magnesium mineral aggregates and a two-stage water addition method to prepare calcium-magnesium mineral concrete, the problems of insufficient ion signal and pollution in coral reef bodies in existing technologies have been solved, achieving accelerated coral growth and eco-friendly coral reef body preparation.
Patent Information
- Application Number
- CN202511802258.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-02-10
AI Technical Summary
Existing concrete-based artificial coral reefs cannot provide the necessary calcium and magnesium ion signals, resulting in low coral larval attachment rates and slow growth. They may also affect the stability of seawater pH, pose a risk of microplastic pollution, and have limited material resources, making modularization difficult.
Using natural calcium-magnesium minerals such as dolomite or anorthite as aggregates, combined with domestically produced high-grade silicate cement and volcanic ash, calcium-magnesium mineral concrete is prepared through a two-stage water addition method. This provides a slow release of calcium and magnesium ions, forming a porous structure to ensure biocompatibility and structural stability.
It improves coral growth rate, reduces negative impact on seawater pH, avoids microplastic pollution, has carbon sequestration capabilities, and is simple to prepare, inexpensive, and easy to mass-produce and modularly deploy.
Smart Images
Figure CN121494450A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of coral reef ecological restoration engineering technology, specifically relating to a method for preparing calcium-magnesium mineral concrete artificial coral reefs. Background Technology
[0002] Coral reef ecosystems, often called the "rainforests of the ocean," function to build, protect, and stabilize reefs, providing wave protection and coastal defense, and preventing land loss. Corals, especially tropical corals, are relatively weak in their ability to adapt to climate. In recent years, due to the adverse effects of excessive greenhouse gas emissions, land reclamation along coastlines, and other human activities leading to global warming and ocean acidification, coral reef ecosystems, which are extremely sensitive to the marine environment, have been affected or damaged to varying degrees, endangering marine ecology and the safety of islands and reefs. Therefore, the restoration of coral reef ecosystems is urgently needed.
[0003] Artificial coral reefs are an irreplaceable engineering method for reversing coral reef degradation. Their core value lies in accelerating coral growth through artificial intervention, rebuilding vital lifelines in ecologically collapsed areas, and making "underwater afforestation" a true cornerstone of marine ecological security. Through the control of raw material composition and structural design, artificial coral reefs can provide an ideal growth environment for coral polyps, accelerating the recovery of the coral ecosystem. Currently, artificial coral reefs mainly consist of concrete, metal, plastic, and stone reefs. Metal artificial reefs promote coral calcification using microcurrents, but they are costly and prone to corrosion after long-term immersion in seawater. Stone artificial reefs, although made of natural materials, have a simple structure and are difficult to modularize. Plastic artificial reefs release microplastics during aging, polluting the surrounding ecosystem. Concrete artificial reefs, with their comprehensive advantages of stability, biocompatibility, cost control, and environmental friendliness, are gradually becoming the mainstream choice for artificial reefs.
[0004] Coral growth is regulated by both inorganic and biological signals. Inorganic signals mainly originate from the physicochemical environmental conditions of the coral reef, including seawater temperature, nutrients in the water, light, pH, and specific ion concentrations. Biological signals arise from the coral's own growth hormones and reproductive processes, or from interactions between symbiotic organisms. These two types of signals interact to determine the health, calcification rate, and overall growth of the coral.
[0005] Most existing concrete-based artificial coral reefs enhance biofouling by providing surface structural designs. Theoretically, concrete-based artificial coral reefs can send growth signals to coral polyps through the slow release of chemicals, achieving an integrated structural and functional design. Calcium and magnesium ions are inorganic signals that play important roles in coral growth. The main component of coral skeletons is aragonite. Sufficient calcium ions in seawater are necessary for coral reef formation. However, the impact of magnesium ions on coral skeletons is more complex. Magnesium ions are essential for the photosynthesis of symbiotic algae such as zooxanthellae; insufficient magnesium ion concentrations inhibit the photosynthesis of these algae, increasing the risk of coral bleaching. Evidence of magnesium calcite has also been found in the early stages of coral reef formation. Therefore, we can consider adding environmentally friendly natural minerals containing calcium and magnesium to artificial coral reefs, releasing these elements into the coral ecosystem through a slow-release process, thereby attracting coral larvae to attach.
[0006] In existing technologies, the preparation of concrete-based artificial coral reefs typically uses traditional sand and gravel as aggregates. These aggregates, primarily composed of SiO2, cannot provide the specific ionic signals required for coral growth, resulting in limited reef induction capabilities. Furthermore, traditional concrete may leach highly alkaline substances into seawater, affecting the stability of the surrounding pH and further inhibiting biofouling. While metal reefs can promote calcification through electrochemical methods, the equipment is complex and maintenance costs are high, making them unsuitable for large-scale deployment. Although plastic reefs are lightweight and easy to mold, the microplastic particles produced during long-term degradation can enter the food chain, causing secondary pollution and posing a potential threat to marine ecosystems. Stone reefs rely on natural rocks, limiting resource availability, and their shapes are difficult to standardize, failing to meet the modular engineering requirements.
[0007] In coral reef restoration practices, existing artificial reefs often overlook the regulatory role of inorganic ion signals. For example, the attachment process of coral larvae is highly dependent on the calcium ion concentration gradient in seawater, but existing concrete reefs cannot achieve the slow release of ions, resulting in low attachment rates and slow growth. Global climate change has exacerbated ocean acidification, reducing natural calcium carbonate saturation and further challenging the coral calcification process. Summary of the Invention
[0008] The purpose of this invention is to overcome the defects of the prior art and provide a method for preparing calcium-magnesium mineral concrete artificial coral reefs.
[0009] The technical solution of the present invention is as follows:
[0010] A method for preparing a calcium-magnesium mineral concrete artificial coral reef includes the following steps:
[0011] (1) Natural calcium and magnesium minerals are crushed and sieved to obtain coarse aggregate and fine aggregate;
[0012] (2) Weigh and mix ordinary silicate cement, admixtures, coarse aggregate and fine aggregate in proportion;
[0013] (3) Add water to the material obtained in step (2) using the two-stage water addition method and stir until plastic concrete is obtained. First, add coarse aggregate and fine aggregate and add some water to stir and wet the surface. Then add ordinary silicate cement and admixtures, and then add the remaining water and stir until the continuity and fluidity meet the standards.
[0014] (4) Fill the plastic concrete obtained in step (3) into the mold and solidify it. Then carry out hydration curing to obtain the final product.
[0015] In a preferred embodiment of the present invention, the ordinary silicate cement is designated as 42.5 or 52.5.
[0016] In a preferred embodiment of the present invention, the natural calcium-magnesium mineral is dolomite or anorthite.
[0017] More preferably, the coarse aggregate has a particle size of 10-20 mesh, and the fine aggregate has a particle size of 100-120 mesh.
[0018] In a preferred embodiment of the present invention, the admixture is fly ash or volcanic ash.
[0019] In a preferred embodiment of the present invention, the mass ratio of the ordinary silicate cement, admixture, coarse aggregate and fine aggregate is 400: 170: 300: 200.
[0020] More preferably, in step (3), the mass ratio of the water to the total mass of the ordinary silicate cement, volcanic ash, coarse aggregate and fine aggregate is 3:1.
[0021] More preferably, in step (3), coarse aggregate and fine aggregate are added first, and half of the water is added and stirred for 4-6 minutes to wet the surface. Then ordinary silicate cement and admixtures are added, and the other half of the water is added and stirred until the continuity and fluidity meet the standards.
[0022] In a preferred embodiment of the present invention, the mold is a silicone mold with a diameter of 10 cm and a thickness of 2 cm.
[0023] In a preferred embodiment of the present invention, the hydration curing is carried out in an environment with humidity not less than 70% and temperature of 20-50°C, and the curing time is 2-4 weeks.
[0024] The beneficial effects of this invention are:
[0025] 1. This invention provides necessary inorganic ion signals (such as calcium and magnesium ions) through the slow release process of calcium and magnesium minerals, attracting coral larvae to attach and accelerating the calcification rate, effectively improving the coral growth rate, and is suitable for ecological restoration projects in tropical coral reef areas.
[0026] 2. The calcium-magnesium mineral concrete artificial coral reef prepared by this invention has a high specific surface area and porous structure, which facilitates ion diffusion; its low alkaline leakage characteristics reduce the negative impact on seawater pH and ensure biocompatibility; its compressive strength reaches 40-60 MPa, providing good structural stability and durability, and resisting ocean current erosion.
[0027] 3. This invention utilizes natural calcium-magnesium minerals (such as dolomite and anorthite) to replace traditional sand and gravel, realizing the resource utilization of natural stone powder; it has carbon fixation capabilities, fixing atmospheric CO2 through the mineral dissolution process; and it releases no harmful substances, avoiding pollution of marine ecology by microplastics or corrosion products.
[0028] 4. This invention uses domestically produced high-grade silicate cement and pozzolanic admixture, combined with a two-stage water addition method and a high water-binder ratio design. It is simple to operate and requires no complex equipment. The curing cycle is 2-4 weeks, the cost is low, and it is easy to carry out large-scale production and modular deployment.
[0029] 5. The calcium-magnesium mineral concrete artificial coral reef prepared by this invention only precipitates a small amount of CaCO3 after being immersed in simulated seawater for 30 days, without any turbidity, demonstrating good stability and impermeability; it has a long service life, reduces maintenance requirements, and is suitable for island and reef protection and marine ecological security projects, providing high economic and social benefits. Attached Figure Description
[0030] Figure 1 This is a scanning electron microscope image of the internal structure of the calcium-magnesium mineral concrete artificial coral reef prepared in Example 1 of the present invention.
[0031] Figure 2 The XRD diffraction pattern of the white precipitate that formed at the bottom of the container after the calcium-magnesium mineral concrete artificial coral reef prepared in Example 1 of this invention was immersed in seawater for 30 days.
[0032] Figure 3 The changes in the calcium-magnesium mineral concrete artificial coral reef prepared in Example 1 of this invention after planting a cup-shaped coral and placing it in an artificial aquaculture tank for two weeks are shown. Detailed Implementation
[0033] The technical solution of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings.
[0034] Example 1
[0035] (1) Select dolomite as concrete aggregate, and crush and sieve it to obtain coarse aggregate (particle size of 10-20 mesh) and fine aggregate (particle size of 100-120 mesh).
[0036] (2) Volcanic ash was selected as a concrete admixture;
[0037] (3) Weigh 400 g of domestic 52.5 grade ordinary Portland cement, 170 g of pozzolanic, 300 g of coarse aggregate and 200 g of fine aggregate, set the water-cement ratio to 1:3 (i.e., the mass ratio of dry concrete to deionized water is 1:3), and then add deionized water according to the water-cement ratio, using a two-stage addition method:
[0038] A. Add the aforementioned coarse and fine dolomite aggregates to the cement mortar mixer, and add 1 / 2 water and mix for 5 minutes to wet the surface of the aggregates and promote the adhesion between the aggregates and cement.
[0039] B. Add cement and volcanic ash to the material obtained in step A, then add the remaining 1 / 2 water to the mixture and continue stirring until a plastic concrete with a certain continuity and fluidity is obtained.
[0040] (4) The obtained plastic concrete is filled into a silicone mold with a diameter of 10 cm and a thickness of 2 cm, and then solidified and shaped. It is then placed in an environment with a humidity of 70% and a temperature of 40 ℃ for constant temperature and humidity hydration curing for 4 weeks to obtain calcium magnesium mineral concrete artificial coral reef.
[0041] The calcium-magnesium mineral concrete artificial coral reef prepared in this embodiment has a compressive strength of 40-45 MPa after testing.
[0042] The calcium-magnesium mineral concrete artificial coral reef was immersed in a sealed container containing 1 L of simulated artificial seawater to test its stability and impermeability in seawater. After 30 days of immersion, only a small amount of white precipitate formed at the bottom of the container, and the artificial seawater remained clear without turbidity. XRD analysis revealed that the white precipitate consisted of aragonite (CaCO3) and magnesium hydroxide (such as...). Figure 2 As shown in the image, this demonstrates that the concrete artificial coral reef continuously dissolves minerals in seawater, slowly releasing alkalinity and calcium and magnesium ions into the surrounding environment. (CO3) 2- During its formation, carbon dioxide from the air is captured, achieving carbon sequestration, while the concrete artificial coral reef structure retains calcium around it. 2+ and CO3 2- The enriched environment provides the necessary chemical conditions for coral growth.
[0043] The internal structure of this calcium-magnesium mineral concrete artificial coral reef was observed using SEM (e.g., Figure 1 As shown in the figure, a large number of micropore structures can be observed inside.
[0044] like Figure 3 As shown, a calcium-magnesium mineral concrete artificial coral reef with a cup-shaped coral planted on it was placed in an artificial aquaculture tank. After 14 days, the coral was observed to be growing normally on the concrete artificial coral reef.
[0045] Example 2
[0046] (1) Select calcium feldspar as concrete aggregate, and crush and sieve it to obtain coarse aggregate (particle size of 10-20 mesh) and fine aggregate (particle size of 100-120 mesh).
[0047] (2) Volcanic ash was selected as a concrete admixture;
[0048] (3) Weigh 400 g of domestic 52.5 grade ordinary Portland cement, 170 g of pozzolanic, 300 g of coarse aggregate and 200 g of fine aggregate, set the water-cement ratio to 1:3 (i.e., the mass ratio of dry concrete to deionized water is 1:3), and then add deionized water according to the water-cement ratio, using a two-stage addition method:
[0049] A. Add the aforementioned coarse and fine calcium feldspar aggregates to the cement mortar mixer, and add 1 / 2 water and mix for 5 minutes to wet the surface of the aggregates and promote the adhesion between the aggregates and cement.
[0050] B. Add cement and volcanic ash to the material obtained in step A, then add the remaining 1 / 2 water to the mixture and continue stirring until a plastic concrete with a certain continuity and fluidity is obtained.
[0051] (4) The subsequent molding and curing processes are the same as in Example 1.
[0052] The calcium-magnesium mineral concrete artificial coral reef prepared in this embodiment has a compressive strength of 55-60 MPa after testing.
[0053] The calcium-magnesium mineral concrete artificial coral reef was immersed in a sealed container containing 1L of simulated artificial seawater to test its stability and impermeability in seawater. The results and phenomena were the same as in Example 1.
[0054] Example 3
[0055] (1) Select dolomite as concrete aggregate, and crush and sieve it to obtain coarse aggregate (particle size of 10-20 mesh) and fine aggregate (particle size of 100-120 mesh).
[0056] (2) Fly ash is selected as a concrete admixture (to replace pozzolanic ash);
[0057] (3) Weigh 400 g of domestic 52.5 grade ordinary Portland cement, 170 g of fly ash, 300 g of coarse aggregate and 200 g of fine aggregate, set the water-cement ratio to 1:3 (i.e., the mass ratio of dry concrete to deionized water is 1:3), then add deionized water according to the water-cement ratio, using a two-stage addition method:
[0058] A. Add the aforementioned coarse and fine dolomite aggregates to the cement mortar mixer, and add 1 / 2 water and mix for 5 minutes to wet the surface of the aggregates and promote the adhesion between the aggregates and cement.
[0059] B. Add cement and fly ash to the material obtained in step A, then add the remaining 1 / 2 water to the mixture and continue stirring until a plastic concrete with a certain continuity and fluidity is obtained.
[0060] (4) The subsequent molding and curing processes are the same as in Example 1.
[0061] The calcium-magnesium mineral concrete artificial coral reef prepared in this embodiment has a compressive strength of 45-50 MPa after testing.
[0062] The calcium-magnesium mineral concrete artificial coral reef was immersed in a sealed container containing 1L of simulated artificial seawater to test its stability and impermeability in seawater. The results and phenomena were the same as in Example 1.
[0063] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.
Claims
1. A method for preparing a calcium-magnesium mineral concrete artificial coral reef, characterized in that: Includes the following steps: (1) Natural calcium and magnesium minerals are crushed and sieved to obtain coarse aggregate and fine aggregate; (2) Weigh and mix ordinary silicate cement, admixtures, coarse aggregate and fine aggregate in proportion; (3) Add water to the material obtained in step (2) using the two-stage water addition method and stir until plastic concrete is obtained. First, add coarse aggregate and fine aggregate and add some water to stir and wet the surface. Then add ordinary silicate cement and admixtures, and then add the remaining water and stir until the continuity and fluidity meet the standards. (4) Fill the plastic concrete obtained in step (3) into the mold and solidify it. Then carry out hydration curing to obtain the final product.
2. The preparation method according to claim 1, characterized in that: The grade of the ordinary silicate cement is 42.5 or 52.
5.
3. The preparation method according to claim 1, characterized in that: The natural calcium-magnesium minerals mentioned are dolomite or anorthite.
4. The preparation method according to claim 3, characterized in that: The coarse aggregate has a particle size of 10-20 mesh, and the fine aggregate has a particle size of 100-120 mesh.
5. The preparation method according to claim 1, characterized in that: The admixture is fly ash or volcanic ash.
6. The preparation method according to claim 1, characterized in that: The mass ratio of the ordinary silicate cement, admixture, coarse aggregate, and fine aggregate is 400: 170: 300:
200.
7. The preparation method according to claim 6, characterized in that: In step (3), the mass ratio of the water to the total mass of the ordinary silicate cement, volcanic ash, coarse aggregate and fine aggregate is 3:
1.
8. The preparation method according to claim 7, characterized in that: In step (3), coarse aggregate and fine aggregate are added first, and half of the water is added and stirred for 4-6 minutes to wet the surface. Then ordinary silicate cement and admixtures are added, and the other half of the water is added and stirred until the continuity and fluidity meet the standards.
9. The preparation method according to claim 1, characterized in that: The mold is a silicone mold with a diameter of 10 cm and a thickness of 2 cm.
10. The preparation method according to claim 1, characterized in that, The hydration curing is carried out in an environment with humidity not lower than 70% and temperature between 20-50 ℃, and the curing time is 2-4 weeks.