A method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits

Abstract

The present invention discloses a method for accelerating the growth rate of an active seafloor hydrothermal sulfide accumulation body, wherein a new hydrothermal vent is excavated at the outer layer of the active seafloor hydrothermal sulfide accumulation body, a growth cover is set at the newly formed hydrothermal vent, and hydrogen sulfide gas is input into the growth cover, so that more hydrogen sulfide or HS formed by hydrogen sulfide hydrolysis is generated. ‑ Combined with dissolved metals in the hydrothermal fluid, the pile driver is then used to carry out pile driving operations on the seabed rock formations outside the hydrothermal sulfide accumulation body to destroy the stability of the seabed rock formations horizontally and vertically, driving more cold seawater to infiltrate into the hydrothermal system below the sulfide accumulation body; through continuous circulation operations, the morphology of the accumulation body is detected and the growth rate of the newly formed sulfide is calculated. This scheme is simple to operate and low in cost. It can effectively increase the growth rate of active seabed hydrothermal sulfide accumulation bodies and provide a theoretical basis and technical reference for deep-sea artificial intervention enrichment and mineralization.

Description

Technical Field

[0001] The invention belongs to the field of development and research of hydrothermal sulfide deposits, and in particular relates to a method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits. Background Art

[0002] Seafloor hydrothermal sulfide deposits are the concentrated manifestation of metal substances erupted from deep hydrothermal fluids on the seafloor. They are a geological phenomenon and important mineral resource that has existed throughout the long history of the Earth's evolution. The growth of active seafloor hydrothermal sulfides is a mineralization process that is developing and evolving. For terrestrial hydrothermal deposits, they are natural mineralization laboratories that can be observed and studied in real time, and can form mineral resources with huge economic value.

[0003] The formation of submarine hydrothermal sulfide deposits in the natural environment is a periodic and discontinuous growth process, with a growth rate that is sometimes fast and sometimes slow. Frequent submarine earthquakes and the collapse of sulfide chimneys can easily block the vents, causing the growth of some areas of the deposits or even the entire deposits to stagnate, thus seriously restricting the scale and development and utilization value of the hydrothermal sulfide deposits. At present, the relevant theoretical basis and methods for artificial intervention in the growth of active submarine hydrothermal sulfide deposits are not yet mature, and technical means are relatively scarce. Therefore, a method to accelerate the growth rate of active submarine hydrothermal sulfide deposits is urgently needed. Summary of the invention

[0004] In order to solve the defect of the prior art that there is a lack of relevant theories and methods for artificial intervention in the growth of active seafloor hydrothermal sulfide accumulations, the present invention proposes a method for accelerating the growth rate of active seafloor hydrothermal sulfide accumulations, so as to effectively improve the growth rate of active seafloor hydrothermal sulfide accumulations and provide a theoretical basis and technical reference for deep-sea artificial intervention enrichment and mineralization.

[0005] The present invention is implemented by adopting the following technical solution: a method for accelerating the growth rate of active seafloor hydrothermal sulfide accumulation, characterized in that it comprises the following steps:

[0006] Step A, selecting a currently growing seafloor hydrothermal sulfide accumulation body, and detecting the morphological characteristics of the accumulation body above the seafloor surface;

[0007] Step B, excavating new hydrothermal vents in the outer layer of the hydrothermal sulfide accumulation body;

[0008] Step C, setting a growth cover at the newly formed hydrothermal vent;

[0009] Step D, inputting hydrogen sulfide gas into the growth hood;

[0010] Step E, carrying out pile driving operation downward on the seabed rock formation outside the hydrothermal sulfide accumulation body;

[0011] Step F: After continuing steps D to E for a period of time, remove the growth cover, perform the morphology detection of step A, calculate the growth rate of the newly formed hydrothermal sulfide accumulation, determine whether the growth rate meets the requirements, and repeat the operations of steps BE.

[0012] Furthermore, in the step B, the seabed mining vehicle continuously excavates along the outer layer of the accumulation body perpendicular to the excavation surface toward the interior of the accumulation body to form a truncated cone-shaped space that is wide at the top and narrow at the bottom, until the excavation is stopped after the hydrothermal fluid eruption occurs.

[0013] Furthermore, the growth cover is a cylindrical structure with a closed top, an open bottom, and a mesh on all sides, and the top size of the growth cover is consistent with the top size of the truncated cone-shaped hydrothermal vent excavated in step B.

[0014] Furthermore, in step D, the input amount of the hydrogen sulfide gas is determined so that the contents of iron ions, copper ions and zinc ions in the hydrothermal fluid in the growth hood are lower than the detection limit:

[0015] When the content of any one of the iron ions, copper ions and zinc ions in the hydrothermal fluid is detected to be higher than the detection limit, hydrogen sulfide gas continues to be input into the growth cover; when the content of iron, copper and zinc ions in the hydrothermal fluid all drops below the detection limit, the injection of hydrogen sulfide gas is stopped.

[0016] Furthermore, in the step E, pile driving is performed at intervals of 50m-100m on the seabed within 100m-500m outside the hydrothermal sulfide accumulation body, and the pile driving operation is performed downward until the width of the rock formation crack exceeds 1cm.

[0017] Furthermore, in the step F, the change S of the growth rate of the hydrothermal sulfide accumulation body is calculated using the following formula:

[0018] S=(V i+h -V i ) / (T i+h -T i );

[0019] Among them, V i and V i+h represent the volume of sulfide accumulation in time periods i and i+h, respectively, T i and T i+h Represent the i-th and i+h time periods respectively.

[0020] Furthermore, the growth cover is made of high temperature resistant and corrosion resistant materials.

[0021] Compared with the prior art, the advantages and positive effects of the present invention are:

[0022] This scheme digs new hydrothermal vents in the outer layer of the active seafloor hydrothermal sulfide accumulation body, sets up growth covers at the newly formed hydrothermal vents, and inputs hydrogen sulfide gas into the growth covers, so that more hydrogen sulfide or HS formed by hydrogen sulfide hydrolysis can be generated. - Combine with dissolved metals in the hydrothermal fluid to precipitate and form sulfides; in addition, pile driving is carried out downward on the seabed rock formation outside the hydrothermal sulfide accumulation body to destroy the stability of the seabed rock formation horizontally and vertically, create more cracks and pressure differences, and drive more cold seawater to penetrate into the hydrothermal system below the sulfide accumulation body;

[0023] This scheme is easy to operate and low in cost. It can effectively accelerate the growth rate of seafloor hydrothermal sulfide accumulation bodies and improve their economic value. It can also increase the growth rate of sulfides in other parts while excavating and mining part of the hydrothermal sulfide accumulation bodies, thereby achieving the goal of sustainable mining while mining. It can also effectively avoid the diffusion loss of metal substances carried to the seabed by the upwelling of deep hydrothermal fluids, thereby increasing the enrichment of metal substances in the hydrothermal sulfide accumulation bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the method flow of an embodiment of the present invention;

[0025] Figure 2 The space formed by excavating the outer layer of the seafloor hydrothermal sulfide accumulation body in the embodiment of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the cylindrical growth cover described in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] This embodiment proposes a method for accelerating the growth rate of active seafloor hydrothermal sulfide accumulation bodies, such as Figure 1 As shown, the following steps are included:

[0029] Step A, selecting a currently growing seafloor hydrothermal sulfide accumulation body, and detecting the morphological characteristics of the accumulation body above the seafloor surface;

[0030] Among them, the morphological characteristics of the selected hydrothermal sulfide accumulation body above the seafloor surface are detected by using AUV or towed seafloor camera and other equipment equipped with near-bottom multi-beam device, which is a relatively mature technical method and will not be elaborated in detail here;

[0031] Step B, excavating the area outside the hydrothermal sulfide accumulation body where no hydrothermal vent exists, until hydrothermal fluid eruption occurs;

[0032] When excavating the outer layer of the accumulation body, the seabed mining vehicle is used to dig perpendicularly to the excavation surface into the accumulation body, and the excavation forms an "inverted frustum" shape with a wide upper part and a narrow lower part ( Figure 2 The purpose of excavation is to destroy the cover layer of the accumulation body and form new hydrothermal vents, so that the upwelling hydrothermal fluid can fully mix with the cold seawater and quickly form hydrothermal sulfides.

[0033] In this embodiment, the excavation shape can also be a rectangular parallelepiped or other shapes. Another benefit of this embodiment, which is preferably excavated into an inverted truncated cone shape that is wide at the top and narrow at the bottom, is that the newly formed hydrothermal eruption activity occurs in the low terrain of the sulfide accumulation body, providing sufficient space for the growth of sulfides, and causing more sulfide particles that migrate and diffuse with the hydrothermal plume to be retained in the truncated cone body instead of diffusing to places far away from the sulfide accumulation body, making it difficult for metal resources to be developed and utilized.

[0034] Among them, it needs to be explained that when excavating a new hydrothermal vent, the accumulation body can be likened to a hill. The external layer generally refers to the excavation at the top of the mountain or slope perpendicular to the excavation surface. This is different from the pile driver operation mentioned below, which is carried out on flat ground several hundred meters away from the hill.

[0035] Step C, placing a cylindrical growth cover at the newly formed hydrothermal vent;

[0036] like Figure 3 As shown, the growth cover is a cylindrical structure with a closed top, an open bottom, and a mesh around it. The size of the top and bottom of the growth cover is consistent with the size of the top of the excavated truncated cone. The growth cover is made of high-temperature resistant and corrosion-resistant materials, such as silicon carbide composite materials, high-temperature thermoplastic resins, etc. The purpose of placing a cylindrical growth cover is to prevent the upwelling hydrothermal fluid from spraying into the seawater vertically and quickly, causing the dissolved and granular metal substances in the seabed hydrothermal fluid to not have time to precipitate out and diffuse and lose at the far end. The mesh around the growth cover provides a channel for the mixing of cold seawater and hydrothermal fluid, increasing the time and degree of their mixing, so that the metal substances in the hydrothermal fluid are precipitated in the sulfide accumulation as much as possible, rather than being diffused into the vast seawater in large quantities, which not only improves the growth rate of the sulfide accumulation, but also achieves a high degree of aggregation of metal substances, which is beneficial to future mining operations.

[0037] Step D, inputting hydrogen sulfide gas into the growth hood;

[0038] Hydrogen sulfide gas is introduced from the hull into the seabed growth hood through a pump and a pipeline. The amount of hydrogen sulfide gas introduced is determined so that the content of iron, copper and zinc ions in the hydrothermal fluid in the growth hood is below the detection limit.

[0039] When the content of iron, copper and zinc ions in the hydrothermal fluid is lower than the detection limit, the injection of hydrogen sulfide gas is stopped; when the content of any one of the iron, copper and zinc ions in the hydrothermal fluid is higher than the detection limit, the hydrogen sulfide gas is continued to be injected into the growth cover. The purpose of injecting hydrogen sulfide gas is to supplement a sufficient amount of readily available divalent sulfur, so that more hydrogen sulfide or HS formed by hydrogen sulfide hydrolysis can be generated. - Combines with dissolved metals in hydrothermal fluids to precipitate sulfides, preventing these dissolved metals from diffusing into ocean waters.

[0040] Among them, detection limit is a more professional term. In layman's terms, it actually refers to whether a method can detect the lowest or highest value of a certain substance or several substances (usually the lowest value is expressed). For example, method A can detect 1g of gold from 1 ton of soil. If the gold content is lower than 1g, it cannot be detected. 1g is the detection limit. How to know whether it is lower than the detection limit is usually achieved by analytical testing. For example, in this embodiment, spectrophotometry can be used to test the iron, copper and zinc ions in the solution.

[0041] Step E, carrying out pile driving operation downward on the seabed rock formation outside the hydrothermal sulfide accumulation body;

[0042] The pile driver operation is carried out at intervals of 50 to 100 meters at the seabed 100 to 500 meters outside the hydrothermal sulfide accumulation body, and the operation is carried out downward until the width of the cracks in the seabed rock layer exceeds 1 cm. The purpose of the pile driver operation is to destroy the stability of the seabed rock layer horizontally and vertically, create more cracks and pressure differences, drive more cold seawater to infiltrate into the hydrothermal system below the sulfide accumulation body, and then drive the circulation of the hydrothermal system, so that more hydrothermal fluids react with the surrounding rocks, leaching more metal substances into the upwelling hydrothermal fluids, and forming new hydrothermal vents and hydrothermal sulfides in various parts of the accumulation body.

[0043] Step F: Continue steps D and E for a period of time and then stop, remove the growth cover, perform the morphology detection of step A, calculate the growth rate of the newly formed sulfide, determine whether the growth rate meets the requirements, and repeat the operations of steps BE.

[0044] The change in the growth rate of the sulfide accumulation body is calculated using the following formula:

[0045] S=(Vi+h -V i ) / (T i+h -T i );

[0046] Among them, V i and V i+h represent the volume of sulfide accumulation in time periods i and i+h, respectively, T i and T i+h Represent the i-th and i+h time periods respectively.

[0047] It can be seen that the scheme of the present invention can increase the growth rate of sulfides in other parts while excavating and exploiting part of the hydrothermal sulfide accumulation body, thereby achieving the goal of sustainable exploitation while mining and growing; effectively avoid the diffusion loss of metal substances carried to the seabed by the upwelling of deep hydrothermal fluids, increase the enrichment of metal substances in the hydrothermal sulfide accumulation body, and greatly enhance the economic value of the seabed hydrothermal sulfide accumulation body; the scheme is simple to operate, low in cost, and can effectively accelerate the growth rate of the seabed hydrothermal sulfide accumulation body.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits, characterized in that: The following steps are involved: Step A, selecting a currently growing seafloor hydrothermal sulfide accumulation body, and detecting the morphological characteristics of the accumulation body above the seafloor surface; Step B, excavating new hydrothermal vents in the outer layer of the hydrothermal sulfide accumulation body; Step C, setting a growth cover at the newly formed hydrothermal vent; Step D, inputting hydrogen sulfide gas into the growth hood; Step E, carrying out pile driving operation downward on the seabed rock formation outside the hydrothermal sulfide accumulation body; Step F: After continuing steps D to E for a period of time, remove the growth cover, perform the morphology detection of step A, calculate the growth rate of the newly formed hydrothermal sulfide accumulation, determine whether the growth rate meets the requirements, and repeat the operations of steps BE.

2. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 1, characterized in that: In step B, the seabed mining vehicle continuously excavates along the outer layer of the accumulation body perpendicularly to the excavation surface toward the interior of the accumulation body to form a truncated cone-shaped space that is wide at the top and narrow at the bottom, until the excavation is stopped after the hydrothermal fluid eruption phenomenon occurs.

3. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 2, characterized in that: The growth cover is a cylindrical structure with a closed top, an open bottom, and a mesh around it. The top size of the growth cover is consistent with the top size of the truncated cone-shaped hydrothermal vent excavated in step B.

4. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 1, characterized in that: In the step D, the input amount of the hydrogen sulfide gas is determined so that the contents of iron ions, copper ions and zinc ions in the hydrothermal fluid in the growth hood are lower than the detection limit: When the content of any one of the iron ions, copper ions and zinc ions in the hydrothermal fluid is detected to be higher than the detection limit, hydrogen sulfide gas continues to be input into the growth cover; when the content of iron, copper and zinc ions in the hydrothermal fluid all drops below the detection limit, the injection of hydrogen sulfide gas is stopped.

5. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 1, characterized in that: In the step E, pile driving is performed at intervals of 50m-100m on the seabed within a range of 100m-500m outside the hydrothermal sulfide accumulation body, and the pile driving operation is performed downward until the width of the rock formation crack exceeds 1cm.

6. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 1, characterized in that: In the step F, the change S of the growth rate of the hydrothermal sulfide accumulation body is calculated using the following formula: S=(V i+h -V i ) / (T i+h -T i ); Among them, V i and V i+h represent the volume of sulfide accumulation in time periods i and i+h, respectively, T i and T i+h Represent the i-th and i+h time periods respectively.

7. The method for accelerating the growth rate of active seafloor hydrothermal sulfide deposits according to claim 1, characterized in that: The growth cover is made of high temperature resistant and corrosion resistant materials.

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