Hydrothermal fluid sea surface extraction and in-line staged enrichment precipitation mining system and method

Abstract

The application provides a hydrothermal fluid sea surface extraction and along-the-way staged enrichment and precipitation mining system and method, and belongs to the field of deep sea resource exploration and mining. A new mining operation mode is provided, which realizes in-situ closed capture to prevent mineralization components from escaping by flashing, uses fluid lifting and along-the-way temperature control to realize intensive precipitation and staged collection, so that the efficient, green and intensive mining of precious metal hydrothermal resources is realized. The mining system has the following: a deep sea in-situ closed drainage and base fixing device, a vertical temperature control conveying main pipeline and an underwater power auxiliary system, a staged enrichment and precipitation collection cabin group along the way, an underwater robot operation and temperature supplementing system, a sea surface power and collection system, and a water surface engineering operation support and final collection system.

Description

Technical Field

[0001] This application relates to the field of deep-sea resource exploration and exploitation, specifically proposing a mining system and method for precious metal hydrothermal systems in marginal back-arc basins, which involves in-situ closed diversion, step-by-step temperature control and graded precipitation, combined surface and underwater high-efficiency extraction, and graded enrichment and precipitation along the flow path. Background Technology

[0002] Modern deep-sea hydrothermal sulfide deposits are significant metallic mineral resources. For example, continental margin back-arc basins, a typical geological structure, exhibit unique geochemical characteristics due to the hydrothermal fluids formed by the water-rock reaction control of felsic volcanic clastic rocks and thick terrigenous feldspar clayey sediments, resulting in hydrothermal fluids with distinct geological features. Compared to conventional mid-ocean ridges, the hydrothermal sulfides in continental margin back-arc basins not only yield high levels of base metals such as copper (Cu), zinc (Zn), and lead (Pb), but are also highly enriched in precious metals such as gold (Au) and silver (Ag), and are associated with high levels of elements such as antimony (Sb) and arsenic (As), making them extremely valuable for economic mining.

[0003] However, due to the extremely complex environment of hydrothermal zones in back-arc basins on continental margins, approximately 95% of the metallic components in the hydrothermal fluids are transferred with the plume. This results in a large amount of liquid-phase minerals rich in gold, silver, and copper failing to precipitate in situ, but instead escaping directly into the cold seawater with the hydrothermal plume, causing severe resource loss. Meanwhile, only a small portion of the metal ions in the hydrothermal fluids precipitate to form sulfide deposits in the hydrothermal zone, but their distribution is difficult to accurately determine.

[0004] Furthermore, sedimentary ore bodies in back-arc basins along continental margins are characterized by their softness and environmental toxicity, with the seabed largely covered by soft sediments. If traditional heavy-duty seabed mining vehicles are used for mechanical crushing, they are highly susceptible to becoming stuck in the soft sediments and unable to operate. Simultaneously, crushing easily stirs up toxic particles such as arsenic and antimony, potentially triggering widespread ecological disasters. Therefore, mining under these geological conditions is prohibitively expensive, and continuous operation in the deep sea is extremely difficult. Mechanically crushing solid ore and then lifting it to the surface via gravity pipes causes significant wear and tear on equipment in the high-viscosity, sediment-rich environment, and the mining costs far outweigh the potential profits.

[0005] Therefore, given the unique hydrothermal fluid characteristics of back-arc basins on continental margins—characterized by "high gold and silver grades, easy escape of precious metal components, shallow water depth, and soft sedimentary basement"—there is an urgent need to design a novel mining method capable of in-situ sealing and capture to prevent the flash evaporation and escape of ore-forming components, and utilizing fluid lifting and along-process temperature control to achieve intensive precipitation and graded collection. In view of this, this application is hereby submitted. Summary of the Invention

[0006] This application proposes a mining system and method for extracting hydrothermal fluids from the sea surface and for graded enrichment and precipitation along the process. It aims to solve the problems of the existing technology of using solid-state mechanical mining on the seabed. It proposes a new mining operation method that uses in-situ closed capture to prevent the flash evaporation and escape of ore-forming components, and uses fluid lifting and temperature control along the process to achieve intensive precipitation and graded collection, so as to realize the efficient, green and intensive mining of precious metal hydrothermal resources.

[0007] To achieve the above-mentioned objectives, the mining system for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation includes the following apparatus: The deep-sea in-situ sealed drainage and base fixing device includes a guide pipe for inserting into the inside of the hydrothermal vent, and a gravity composite fixing base for fixing the guide pipe on the soft seabed substrate and preventing fluid flash evaporation and overflow. The vertical temperature-controlled transport main pipeline and underwater power auxiliary system include a high-efficiency insulated transport pipeline as the main pipeline. Inside the high-efficiency insulated transport pipeline, there are multiple first seawater injection valves, second seawater injection valves, and third seawater injection valves for injecting cold seawater into the pipe to adjust the fluid temperature and oxidation-reduction potential. There is also at least one underwater auxiliary pump for assisting the surface extraction power pump in providing negative pressure and suction power. The process-grade enrichment and sedimentation collection chamber group includes at least three detachable collection chambers set at different water depths according to a preset stepped temperature range; the inner wall of each detachable collection chamber is provided with an induced crystallization coating for guiding the directional growth of high-grade minerals, and each detachable collection chamber is provided with an underwater cable interface for underwater robot operation. The underwater robot operation and maintenance and heating system includes an underwater robot for disassembling and reassembling a detachable collection compartment filled with minerals underwater. The underwater robot heats and reheats the target detachable collection compartment by connecting the power supply / heating cable to the underwater cable interface, and maintains a constant temperature inside the compartment in conjunction with pipe heat dissipation and seawater injection valve. The marine power and collection system is used in conjunction with the underwater auxiliary pump to drive the hydrothermal fluid upward and to cooperate with the transfer vessel to recover the collection compartment dismantled by the underwater robot; it includes a surface operation support platform and a marine extraction power pump deployed on the surface operation support platform; The surface engineering operation support and final collection system is equipped with a variable frequency high-pressure fluid extraction power pump set for controlling fluid speed. The detachable collection compartment is disassembled by an underwater robot and then transported to land by an auxiliary vessel for subsequent refining operations. The bottom of the gravity-type composite fixing base is equipped with a wide anti-sinking skirt.

[0008] The flow guide tube is made of nickel-based high-temperature alloy and its outer wall is coated with a silicon carbide ceramic layer.

[0009] The high-efficiency insulated transport pipeline is equipped with a temperature sensor inside the pipeline, and its inner wall is coated with a polytetrafluoroethylene anti-stick coating.

[0010] The graded enrichment and sedimentation collection chamber assembly includes three detachable metal mineral collection chambers, each equipped with flanges and locking mechanisms for quick assembly and disassembly with the high-efficiency insulated transport pipeline. The first detachable metal mineral collection chamber is located near the bottom of the high-efficiency insulated transport pipeline, maintaining an internal temperature between 300-350°C. The second detachable metal mineral collection chamber is located in the middle of the high-efficiency insulated transport pipeline, maintaining an internal temperature between 150-300°C. The third detachable metal mineral collection chamber is located near the sea surface of the high-efficiency insulated transport pipeline, maintaining an internal temperature below 150°C. A third seawater injection valve is connected to the front end of the third detachable metal mineral collection chamber.

[0011] Based on the above-mentioned hydrothermal fluid surface extraction and in-process graded enrichment and precipitation mining system, this application also proposes the following hydrothermal fluid surface extraction and in-process graded enrichment and precipitation mining method: Acidic high-temperature hydrothermal fluid is drawn into an in-situ closed temperature-controlled pipeline using a negative pressure suction of an underwater auxiliary pump; the temperature drop rate of the hydrothermal fluid during its upward movement within the vertical transport main pipeline is controlled by utilizing heat exchange between the pipeline and the cold seawater outside the pipeline, combined with manual adjustment of the seawater injection valve and active heating by an underwater robot; and detachable metal mineral collection chambers are set up in different temperature ranges; the hydrothermal fluid is cooled and precipitated in the detachable metal mineral collection chambers at different temperature windows, with different metal sulfides crystallizing and precipitating sequentially.

[0012] Each removable metal mineral collection chamber has an induced crystallization coating applied to its inner wall. The first removable metal mineral collection chamber maintains a temperature between 350-300℃ for the graded collection of native gold and coarse-grained chalcopyrite sands. The second removable metal mineral collection chamber maintains a temperature between 300-150℃ for the graded collection of polymetallic solid sands rich in silver, zinc, and lead. The third removable metal mineral collection chamber maintains a temperature below 150℃ for the collection of precipitated harmful elements such as arsenic and antimony.

[0013] The system employs a multi-stage relay pressurized underwater auxiliary water pump group, deploys underwater robots for underwater hull assembly and disassembly, and uses a dedicated interface to actively heat each detachable metal mineral collection chamber with electric heating. This, combined with pipeline heat dissipation and water injection regulation, ensures that the temperature inside the chamber is maintained within the preset crystallization range.

[0014] The mining method includes the following implementation process: Step S1: In-situ closed deployment and underwater dynamic coordination; First, a gravity-type composite fixed base is placed on the target hydrothermal vent using a surface operation support platform; then, a guide pipe is tightly inserted into the hydrothermal vent channel for in-situ closed interception. The upper end of the gravity-type composite fixed base is connected to a vertically conveying, high-efficiency insulated transport pipeline via a flexible pipe. Start the surface extraction power pump deployed on the surface operation support platform, and at the same time start at least one underwater auxiliary pump. The multi-stage pump set works together to provide negative pressure suction, control the flow velocity in the pipe, and make the hydrothermal fluid move steadily upward along the vertically transported high-efficiency insulated transport pipeline. Step S2: Pipeline-side stepped temperature control and robot-assisted temperature adjustment; As the fluid moves upward along the high-efficiency insulated transport pipeline, it is cooled by natural heat dissipation through the pipeline and by seawater introduced through seawater injection valves at all levels. When the temperature of a reaction chamber is lower than the preset range, an underwater robot connects the power supply / heating cable to the interface of the corresponding detachable metal mineral collection chamber for electric heating to maintain each chamber within the preset constant temperature window. Step S3: Graded and stepped precipitation and solidification of harmful elements; As the fluid flows through the highly efficient insulated transport pipeline, under the combined effects of insulation, seawater injection valve regulation, and underwater robot heating, it sequentially enters the removable metal mineral collection chambers set in different zones: in the 350-300℃ range, it flows through the first removable metal mineral collection chamber, where coarse chalcopyrite and native gold particles are precipitated and collected under the guidance of the mineral coating on its inner wall; in the 300-150℃ range, it flows through the second removable metal mineral collection chamber, where silver-, zinc-, and lead-rich polymetallic solid particles are precipitated and collected under the guidance of the coating; the fluid is injected with iron salts and oxidants through the third seawater injection valve, and flows through the second removable metal mineral collection chamber in the range below 150℃, where it reacts, solidifies, and captures precipitates of ferric arsenate and ferric antimonate; The oxidation-reduction potential is adjusted at the third seawater injection valve and a special iron salt is added to oxidize As and Sb and generate insoluble iron arsenate and iron antimonate coprecipitates. The above-mentioned harmful element precipitate particles are captured and retained in the third detachable metal mineral collection chamber. The detoxified wastewater is safely discharged into the sea. Step S4: Underwater disassembly and assembly and sea surface transfer; Continue to control the internal flow rate of the high-efficiency insulated transport pipeline to remain within the preset range. When the solids in each detachable metal mineral collection chamber are enriched to the preset amount, the underwater robot actively disassembles the fully loaded reaction chamber underwater and transports it to the land-based refinery via a transfer ship. At the same time, the underwater robot reassembles and resets the new reaction chamber.

[0015] In step S2, the outer wall of the high-efficiency insulated transport pipeline is provided with an insulation layer, and the inner wall of the pipeline is coated with polytetrafluoroethylene. Temperature sensors are installed inside the first, second, and third detachable metal mineral collection chambers to adjust the injection flow of seawater according to the temperature, thereby realizing a stepped temperature-controlled graded sedimentation process.

[0016] In summary, this application has the following beneficial effects and advantages compared with the prior art: 1. This application proposes an intensive fluid mining system and method for precious metal hydrothermal systems in marginal back-arc basins, utilizing in-situ closed-loop diversion, step-controlled temperature control and graded precipitation along the flow path, combined surface and underwater high-efficiency extraction, and robot-assisted maintenance. A continuous production mode of "in-situ closed-loop interception, shallow-water decompression pumping, step-controlled temperature control along the flow path, and graded precipitation collection" is proposed.

[0017] 2. This application can maximize the recovery of precious metal resources (Au, Ag). Through in-situ closed flow guidance and heat preservation and temperature control technology, it completely suppresses the flash evaporation and escape of hydrothermal fluids in the back-arc basin of the marginal sea surface at the vent. It completely traps the natural gold particles and silver-rich components that are very easy to diffuse and escape with the plume in the pipeline and precipitates them in stages, thereby effectively improving the comprehensive recovery rate of precious metal resources.

[0018] 3. This application realizes the step-by-step graded collection of minerals and the centralized pretreatment of harmful elements. By using the temperature control technology along the process and the in-chamber induced crystallization coating, basic metals such as gold, silver, and copper, as well as harmful elements such as arsenic and antimony, are sequentially precipitated and graded at different temperature windows. This not only reduces the difficulty of subsequent refining on the sea surface and land, but also realizes the solidification and centralized collection of harmful elements.

[0019] 4. This application has the advantages of avoiding geological risks from soft sediments and strong environmental protection and toxicity control capabilities. The mining system does not rely on seabed mining vehicles; the seabed portion is only a gravity-type base, completely avoiding the risk of the base sinking into soft sediments. Arsenic, antimony, and other substances associated with hydrothermal vents in the marginal back-arc basin are centrally filtered and precipitated in closed temperature-controlled pipes and collection chambers. The filtered and detoxified tailwater is discharged into the deep sea, effectively preventing harmful elements from spreading to the upper fishery ecosystem.

[0020] 5. This application can improve power reliability and has strong underwater automated operation and maintenance capabilities. The underwater auxiliary pump set solves the problem of insufficient power for long-distance lifting in the deep sea. The underwater robot realizes the online underwater disassembly, assembly and transfer of the reaction chamber and precise temperature control, ensuring the long-term continuous and stable operation of the mining method. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. Some specific embodiments of this application will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale.

[0022] Figure 1 This is a schematic diagram of the mining system for hydrothermal fluid extraction from the sea surface and graded enrichment and sedimentation along the route, as proposed in this application. Figure 2 A schematic cross-sectional view of a hydrothermal vent fluid collection device; In the above-mentioned attached figures, the following components are included: 1. Deep-sea in-situ closed diversion and base fixing device; 2. High-efficiency heat-insulated transport pipeline; 3. Hydrothermal fluid; 4. First detachable metal mineral collection tank; 5. First seawater injection valve; 6. Second detachable metal mineral collection tank; 7. Second seawater injection valve; 8. First underwater auxiliary pump; 9. Third detachable metal mineral collection tank; 10. Third seawater injection valve; 11. Second underwater auxiliary pump; 12. Transfer vessel; 13. Sea surface extraction power pump; 14. Surface operation support platform; 15. Wastewater discharge; 16. Underwater robot; 17. Power supply / heating cable; 18. Anti-sinking wide skirt; 19. Gravity composite fixing base; 20. Original high-temperature hydrothermal fluid; 21. Diversion pipe. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] Example 1, as Figure 1 As shown, the hydrothermal fluid sea surface extraction and in-process graded enrichment and sedimentation mining system includes the following apparatus: The deep-sea in-situ sealed drainage and base fixing device 1 includes a high-temperature and corrosion-resistant guide pipe 21 for insertion into the hydrothermal vent, and a gravity-type composite fixing base 19 for fixing the guide pipe 21 on the soft seabed substrate and preventing fluid flash evaporation and overflow. The bottom of the gravity-type composite fixing base 19 is provided with a wide anti-sinking skirt 18. The guide pipe 21 is preferably made of nickel-based high-temperature alloy, and its outer wall is coated with a silicon carbide ceramic layer that is resistant to thermal shock and erosion.

[0025] The vertical temperature-controlled transport main pipeline and underwater power auxiliary system are connected to the deep-sea in-situ closed diversion and base fixing device 1 and the surface operation support platform 14. It includes a high-efficiency insulated transport pipeline 2 as the main pipeline. An insulation layer is provided between the inner and outer walls of the high-efficiency insulated transport pipeline 2 to prevent the fluid from cooling too quickly due to excessive temperature differences. A temperature sensor is installed inside the high-efficiency insulated transport pipeline 2, and multiple seawater injection valves (first seawater injection valve 5, second seawater injection valve 7, and third seawater injection valve 10) are installed along the pipeline to inject cold seawater into the pipe to precisely adjust the fluid temperature and oxidation-reduction potential. At least one underwater auxiliary pump, such as a first underwater auxiliary pump 8 and a second underwater auxiliary pump 11, is also installed along the pipeline to assist the surface extraction power pump in providing negative pressure and suction power. The inner wall of the high-efficiency insulated transport pipeline 2 is coated with a polytetrafluoroethylene anti-stick coating, and internal anti-sticking and anti-clogging treatment and maintenance can be performed periodically using ultrasonic vibration anti-clogging equipment.

[0026] The graded enrichment and sedimentation collection chambers are arranged from bottom to top along the high-efficiency insulated transport pipeline 2; including at least three detachable collection chambers arranged at different water depths according to preset stepped temperature ranges, such as the first detachable metal mineral collection chamber 4, the second detachable metal mineral collection chamber 6, and the third detachable metal mineral collection chamber 9; the inner wall of each detachable collection chamber is provided with an induced crystallization coating for guiding the directional growth of high-grade minerals, and each detachable collection chamber is provided with an underwater cable interface for underwater robot operation; The detachable gold collection compartment has a flange and locking mechanism that allows for quick assembly and disassembly with the high-efficiency insulated transport pipeline 2, enabling the underwater robot 16 to perform disassembly and assembly operations underwater. The first detachable metal mineral collection chamber 4 is located near the bottom of the high-efficiency insulated transport pipeline 2. The temperature inside the chamber is maintained between 350-300℃ for graded collection of the first-stage natural gold and coarse chalcopyrite sand. The second detachable metal mineral collection chamber 6 is located in the middle of the high-efficiency insulated transport pipeline 2. The temperature inside the chamber is maintained between 300-150°C for graded collection of silver-rich, zinc-, and lead-rich polymetallic solid mineral sands. The third detachable metal mineral collection chamber 9 is located near the sea surface of the high-efficiency insulated transport pipeline 2. The temperature inside the chamber is maintained below 150°C to collect precipitated harmful elements such as arsenic and antimony.

[0027] The front end of the third detachable metal mineral collection chamber 9 is connected to a third seawater injection valve 10, which is used to inject an auxiliary precipitant. The auxiliary precipitant is preferably an iron salt and an oxidant, so that the residual arsenic and antimony in the fluid are solidified into insoluble ferric arsenate and ferric antimonate precipitates under the conditions of lower temperature and higher redox potential, thereby improving the centralized capture efficiency.

[0028] The underwater robot operation and maintenance and heating system includes an underwater robot 16 for disassembling and reassembling a detachable collection compartment filled with minerals underwater. The underwater robot 16 is equipped with a robotic arm and a power supply / heating cable 17. The underwater robot 16 heats and reheats the target collection compartment by connecting the power supply / heating cable 17 to the underwater cable interface, and maintains a constant temperature inside the compartment in conjunction with pipe heat dissipation and seawater injection valve. The surface power and collection system is used in conjunction with underwater auxiliary pumps (such as the first underwater auxiliary pump 8 and the second underwater auxiliary pump 11) to drive the hydrothermal fluid upward and to cooperate with the transfer vessel 12 to recover the collection tank dismantled by the underwater robot 16; it includes a surface operation support platform 14 and a surface extraction power pump 13 deployed on the surface operation support platform 14. The surface engineering operation support and final collection system, as a mining operation support platform, is equipped with a variable frequency high-pressure fluid extraction power pump set for controlling fluid speed. The detachable collection compartment is disassembled by the underwater robot 16 and then transported to land by an auxiliary vessel for subsequent refining operations.

[0029] Based on the above-mentioned mining system of sea surface extraction of hydrothermal fluids and graded enrichment and precipitation along the route, this embodiment selects the operation area as an active hydrothermal field in the back-arc basin at the edge of a certain sea area, with a water depth of about 1500-2500 meters. The hydrothermal fluids in this area are rich in Au, Ag, Cu, Zn and Pb, and the seabed surface is covered with several meters of soft muddy sediments.

[0030] In the aforementioned area, the following mining method is adopted: hydrothermal fluid extraction from the sea surface and graded enrichment and sedimentation along the route: Acidic high-temperature hydrothermal fluid (300-350℃) is drawn into an in-situ closed temperature-controlled pipeline using a surface variable frequency pump and an underwater auxiliary pump set under negative pressure. The rate of temperature drop of the hydrothermal fluid during its upward movement within the vertical transport main pipeline is controlled by the heat exchange between the pipeline and the cold seawater outside the pipeline, combined with manual adjustment of the water injection valve and active heating by an underwater robot. Collection chambers are set up in different temperature ranges. The hydrothermal fluid is cooled and precipitated in the collection chambers at different temperature windows, and different metal sulfides crystallize out in sequence.

[0031] Specifically, in order to control the stepwise decrease in temperature of the fluid inside the pipeline, an induced crystallization coating is applied to the inner wall of each collection chamber. In the first detachable metal mineral collection chamber 4 (the temperature inside the chamber is maintained between 350-300℃), native gold and coarse chalcopyrite sand are collected in stages. In the second detachable metal mineral collection chamber 6 (the temperature inside the chamber is maintained between 300-150℃), silver-rich, zinc-, and lead-rich polymetallic solid mineral sands are collected in stages. In the third detachable metal mineral collection chamber 9 (the temperature inside the chamber is maintained below 150°C), precipitated harmful elements such as arsenic and antimony are collected.

[0032] To further enhance the power of long-distance transport of high-viscosity fluids and address the challenges of underwater operations and localized temperature fluctuations, a multi-stage relay-pressurized underwater auxiliary pump set is adopted. An underwater robot (ROV) is also configured for underwater hull assembly and disassembly, and for active electric heating of each collection chamber via a dedicated interface. This ensures that the temperature inside the chamber is precisely maintained within the preset crystallization range, in conjunction with pipeline heat dissipation and water injection regulation.

[0033] The method includes the following implementation steps: Step S1: In-situ closed deployment and underwater dynamic coordination; First, the gravity-type composite fixed base 19 is placed on the target hydrothermal vent using the surface operation support platform 14. The bottom of the gravity-type composite fixed base 19 is provided with a wide anti-sinking skirt 18 that extends laterally to distribute the base's own weight and the negative pressure load generated by suction, preventing the base from sinking deeply. A high-temperature resistant and highly corrosion-resistant guide pipe 21 extends vertically downward from the center of the gravity-type composite fixed base 19. The guide pipe 21 is tightly inserted into the hydrothermal vent channel for in-situ closed interception. Due to the depth of the trench and the relatively low pressure (approximately 15 MPa), the original high-temperature hydrothermal fluid 20 is prone to flash evaporation and escape. The guide pipe 21 and the base 19 tightly compact the area around the nozzle through their own counterweights to achieve closed interception, forcing all the original high-temperature hydrothermal fluid 20 that has not yet flashed and separated into phases to enter the guide pipe 21.

[0034] The upper end of the gravity-type composite fixed base 19 is connected to the vertically conveying high-efficiency insulated transport pipeline 2 through a flexible pipe; Start the surface extraction power pump 13 deployed on the surface operation support platform 14, and simultaneously start the first underwater auxiliary pump 8 and the second underwater auxiliary pump 11 to prevent insufficient power due to long-distance lifting in the deep sea and high-viscosity fluid. Multi-stage pump sets work together to provide negative pressure suction, control the flow velocity in the pipe, and make the hydrothermal fluid 3 move steadily upward along the vertically transported high-efficiency insulated transport pipe 2; Step S2: Pipeline-side stepped temperature control and robot-assisted temperature adjustment; As the fluid moves upward along the high-efficiency insulated transport pipeline 2, it is cooled by natural heat dissipation through the pipeline and by seawater introduced through the seawater injection valves at each level. When the temperature of a certain reaction chamber is lower than the preset range, the underwater robot 16 connects the power supply / heating cable 17 to the interface of the corresponding collection chamber for electric heating to maintain each chamber at the preset constant temperature window. The outer wall of the high-efficiency insulated transport pipeline 2 is provided with an insulation layer to prevent the fluid from cooling too quickly due to excessive temperature difference; To ensure precise control of the step-down cooling process of the fluid inside the pipeline, the inner wall of the high-efficiency insulated transport pipeline 2 is coated with polytetrafluoroethylene to prevent particle adsorption and blockage. Temperature sensors are installed inside the first removable metal mineral collection chamber 4, the second removable metal mineral collection chamber 6, and the third removable metal mineral collection chamber 9. The injection flow of seawater is adjusted according to the temperature, thereby precisely controlling the temperature drop of the fluid in the pipe and realizing a step-by-step temperature-controlled graded sedimentation process.

[0035] Step S3: Graded and stepped precipitation and solidification of harmful elements; The original high-temperature hydrothermal fluid 20 has a temperature of ≈350℃ at the nozzle and a redox potential of ≈-200 to -100mV (strong reducing oxygen-free environment). The metals in the hydrothermal fluid mainly exist in the form of chloride complexes and sulfhydryl complexes. When the fluid passes through the high-efficiency insulated transport pipe 2, under the combined action of insulation, water injection valve regulation, and heating replenishment by the underwater robot 16, it sequentially enters the collection chambers set in different zones: in the 350-300℃ zone, it flows through the first detachable metal mineral collection chamber 4, where coarse chalcopyrite and native gold particles are precipitated and collected under the guidance of the mineral coating on its inner wall; in the 300-150℃ zone, it flows through the second detachable metal mineral collection chamber 6, where silver-zinc-lead polymetallic solid particles are precipitated and collected under the guidance of the coating; the fluid is injected with iron salt and oxidant through the third seawater injection valve 10, and flows through the second detachable metal mineral collection chamber 9 in the zone below 150℃, where it reacts, solidifies, and captures ferric arsenate and ferric antimonate precipitates; specifically, The first stage involves precipitation in the high-temperature zone and collection in the first collection chamber. The fluid enters the first detachable metal mineral collection chamber 4 located near the bottom of the high-efficiency insulated transport pipeline 2, where the temperature is maintained at 350-300℃. As the redox potential increases and the fluid's reducing power decreases, the stability of the gold and copper chloride complexes and sulfide-hydrogen complexes decreases sharply. At this point, the temperature-sensitive gold component (HS)... - The presence of complexes and copper components (in the form of chloride complexes) rapidly saturates, quickly precipitating coarse-grained chalcopyrite and associated native gold particles. The first detachable metal mineral collection chamber 4 has a specific mineral coating inside to guide and control the directional growth of high-grade minerals. Natural gold precipitation: 2Au(HS)2 - +2H + →2Au↓+4H2S (1) Chalcopyrite precipitate: CuCl2 - +Fe 2+ +2H₂S→CuFeS₂↓+4H + +2Cl - (2) During this stage, the rapidly precipitated coarse chalcopyrite and gold-rich microparticles are initially collected in the first detachable metal mineral collection chamber 4; while sulfides of silver, zinc, lead, etc., remain in the fluid due to their high solubility product at this temperature window.

[0036] The second stage involves precipitation in the mid-temperature zone and collection in the second collection chamber. The fluid flows out of the first detachable metal mineral collection chamber 4 and is further temperature-controlled within the insulated pipe (by introducing cold seawater for regulation or supplemental heating by a robot). As the fluid flows through the middle water depth, the temperature drops to the 300-150℃ range, and the redox potential rises to -50 to 0mV. The increased pH lowers the H2S concentration threshold required for sulfide precipitation, and the increased redox potential promotes the reduction of sulfur (H2S / HS). - Oxidation of the sulfur anion increases the activity of the sulfur anion, reaching the solubility product conditions of silver, zinc, and lead sulfides, and precipitation begins sequentially. Argentite precipitate: 2AgCl2 - +H₂S→Ag₂S↓+2H + +4Cl - (3) Deep red silver ore precipitate: 3AgCl2 - +Sb(OH)3 + 3H2S → Ag3SbS3↓ + 3H + +6Cl - +3H2O (4) Sphalerite precipitation: ZnCl2 + H2S → ZnS↓ + 2H + +2Cl - (5) Galena precipitate: PbCl3 - +H₂S→PbS↓+2H + +3Cl - (6) The sphalerite and galena formed in this stage are often rich in silver complex inclusions. The mid-temperature section design enables the joint precipitation of Ag with Zn and Pb, which are then collected in the second detachable metal mineral collection chamber 6. The interior of the second detachable metal mineral collection chamber 6 is also equipped with a mineral coating to guide the crystallization into high-grade ore sand. The third stage involves the release of toxins in the cryogenic / toxic control zone and the collection in the third collection chamber. The residual fluid temperature is controlled to approximately 150°C, and it sequentially enters the third removable metal mineral collection chamber 9 near the sea surface. At this stage, most of the metal resources have precipitated. The decrease in sulfur fugacity promotes the formation of orpiment and stibnite from residual harmful elements As and Sb. Orpiment precipitate: 2H3AsO3 (arsenous acid) + 3H2S → As2S3↓ + 6H2O (7) Stibnite precipitation: 2H3SbO3 (antimonylic acid) + 3H2S → Sb2S3↓ + 6H2O (8) Based on the small amount of natural precipitation of orpiment and stibnite, the concentrated solidification treatment of harmful elements is as follows: The system artificially adjusts the redox potential at the third seawater injection valve 10 and adds a specially prepared iron salt to oxidize As(III) and Sb(III) and generate the following insoluble ferric arsenate and ferric antimonate coprecipitates: Arsenic fixation (ferric arsenate precipitation): 2H3AsO3 + O2 → 2H3AsO4 (9) H3AsO4+Fe 3+ →FeAsO4↓+3H + (10) Antimony fixation (ferric antimony precipitation): 2H3SbO3+O2→2Sb(OH)5 (11) Sb(OH)₅+Fe 3+ →FeSbO4↓+3H2O+3H + (12) The aforementioned harmful element precipitates are captured and retained in the third removable metal mineral collection chamber 9 to prevent them from escaping into the marine environment; the detoxified wastewater 15 is safely discharged into the sea. Step S4: Underwater disassembly and assembly and sea surface transfer; Continue to control the internal flow velocity of the high-efficiency insulated transport pipeline 2 to keep it within the preset range, such as 2.5-4 m / s. If the flow velocity is too fast, the metal ions will not be able to precipitate sufficiently, and if it is too slow, the pipeline may be blocked; ensure stable transport of fluid in the pipeline. Once the solids in each collection chamber have accumulated to a preset amount, the underwater robot 16 actively disassembles the fully loaded reaction chamber underwater and transports it to the land-based refinery via the transfer vessel 12; at the same time, the underwater robot 16 reassembles and resets the new reaction chamber.

[0037] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A mining system for hydrothermal fluid extraction from the sea surface and graded enrichment and sedimentation along the flow path, characterized in that: include, The deep-sea in-situ sealed drainage and base fixing device includes a guide pipe for inserting into the inside of the hydrothermal vent, and a gravity composite fixing base for fixing the guide pipe on the soft seabed substrate and preventing fluid flash evaporation and overflow. The vertical temperature-controlled transport main pipeline and underwater power auxiliary system include a high-efficiency insulated transport pipeline as the main pipeline. Inside the high-efficiency insulated transport pipeline, there are multiple first seawater injection valves, second seawater injection valves, and third seawater injection valves for injecting cold seawater into the pipe to adjust the fluid temperature and oxidation-reduction potential. There is also at least one underwater auxiliary pump for assisting the surface extraction power pump in providing negative pressure and suction power. The process-grade enrichment and sedimentation collection chamber group includes at least three detachable collection chambers set at different water depths according to a preset stepped temperature range; the inner wall of each detachable collection chamber is provided with an induced crystallization coating for guiding the directional growth of high-grade minerals, and each detachable collection chamber is provided with an underwater cable interface for underwater robot operation. The underwater robot operation and maintenance and heating system includes an underwater robot for disassembling and reassembling a detachable collection compartment filled with minerals underwater. The underwater robot heats and reheats the target detachable collection compartment by connecting the power supply / heating cable to the underwater cable interface, and maintains a constant temperature inside the compartment in conjunction with pipe heat dissipation and seawater injection valve. The marine power and collection system is used in conjunction with the underwater auxiliary pump to drive the hydrothermal fluid upward and to cooperate with the transfer vessel to recover the collection compartment dismantled by the underwater robot; it includes a surface operation support platform and a marine extraction power pump deployed on the surface operation support platform; The surface engineering operation support and final collection system is equipped with a variable frequency high-pressure fluid extraction power pump set for controlling fluid speed. The detachable collection compartment is disassembled by an underwater robot and then transported to land by an auxiliary vessel for subsequent refining operations. The bottom of the gravity-type composite fixing base is equipped with a wide anti-sinking skirt.

2. The mining system for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation according to claim 1, characterized in that: The flow guide tube is made of nickel-based high-temperature alloy and its outer wall is coated with a silicon carbide ceramic layer.

3. The mining system for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation according to claim 1, characterized in that: The high-efficiency insulated transport pipeline is equipped with a temperature sensor inside the pipeline, and its inner wall is coated with a polytetrafluoroethylene anti-stick coating.

4. The mining system for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation according to claim 1, characterized in that: The graded enrichment and sedimentation collection chamber assembly includes three detachable metal mineral collection chambers, each equipped with a flange and locking mechanism for quick assembly and disassembly with the high-efficiency insulated transport pipeline. The first detachable metal mineral collection chamber is located near the bottom of the high-efficiency insulated transport pipeline, and the temperature inside the chamber is maintained between 350-300℃. The second detachable metal mineral collection chamber is located in the middle of the high-efficiency insulated transport pipeline, and the temperature inside the chamber is maintained between 300-150℃. The third detachable metal mineral collection chamber is located near the sea surface of the high-efficiency insulated transport pipeline, and its internal temperature is maintained below 150°C; a third seawater injection valve is connected to the front end of the third detachable metal mineral collection chamber.

5. A mining method for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation using a mining system based on hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation as described in claim 4, characterized in that: Acidic high-temperature hydrothermal fluid is drawn into an in-situ closed temperature-controlled pipeline using the negative pressure of an underwater auxiliary pump. The rate of temperature drop of the hydrothermal fluid during its upward movement within the vertical transport main pipeline is controlled by the heat exchange between the pipeline and the cold seawater outside the pipeline, combined with the manual adjustment of the seawater injection valve and the active heating by the underwater robot. Detachable metal mineral collection chambers are set up in different temperature ranges. The hydrothermal fluid is cooled and precipitated in a detachable metal mineral collection chamber at different temperature windows, and different metal sulfides crystallize out in sequence.

6. The mining method for hydrothermal fluid extraction from the sea surface and graded enrichment and sedimentation along the flow path, as described in claim 5, is characterized in that: Each removable metal mineral collection chamber has an inducible crystallization coating applied to its inner wall; among which, The first detachable metal mineral collection chamber maintains a temperature between 350-300℃ for graded collection of native gold and coarse chalcopyrite sand. The second detachable metal mineral collection chamber maintains a temperature between 300-150℃ for graded collection of silver-, zinc-, and lead-rich polymetallic solid mineral sands. The third detachable metal mineral collection chamber maintains a temperature below 150°C to collect precipitated harmful elements such as arsenic and antimony.

7. The mining method for hydrothermal fluid extraction from the sea surface and graded enrichment and sedimentation along the flow path, as described in claim 6, is characterized in that: The system employs a multi-stage relay pressurized underwater auxiliary pump set, deploys an underwater robot for underwater hull assembly and disassembly, and uses a dedicated interface to actively heat each detachable metal mineral collection chamber with electric heating. This, combined with pipeline heat dissipation and water injection regulation, ensures that the temperature inside the chamber is maintained within the preset crystallization range.

8. The mining method for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation according to claim 7, characterized in that: The implementation process includes the following steps: Step S1: In-situ closed deployment and underwater dynamic coordination; First, the gravity-type composite fixed base is placed on the target hydrothermal vent using a surface operation support platform; The guide tube is tightly inserted into the hydrothermal vent channel for in-situ closed interception; The upper end of the gravity-type composite fixed base is connected to a vertically conveying, high-efficiency insulated transport pipeline via a flexible pipe. Start the surface extraction power pump deployed on the surface operation support platform, and at the same time start at least one underwater auxiliary pump. The multi-stage pump set works together to provide negative pressure suction, control the flow velocity in the pipe, and make the hydrothermal fluid move steadily upward along the vertically transported high-efficiency insulated transport pipeline. Step S2: Pipeline-side stepped temperature control and robot-assisted temperature adjustment; As the fluid moves upward along the high-efficiency insulated transport pipeline, it is cooled by natural heat dissipation through the pipeline and by seawater introduced through seawater injection valves at all levels. When the temperature of a reaction chamber is lower than the preset range, an underwater robot connects the power supply / heating cable to the interface of the corresponding detachable metal mineral collection chamber for electric heating to maintain each chamber within the preset constant temperature window. Step S3: Graded and stepped precipitation and solidification of harmful elements; As the fluid flows through the highly efficient insulated transport pipeline, under the combined effects of insulation, seawater injection valve regulation, and underwater robot heating, it sequentially enters the removable metal mineral collection chambers set in different zones: in the 350-300℃ range, it flows through the first removable metal mineral collection chamber, where coarse chalcopyrite and native gold particles are precipitated and collected under the guidance of the mineral coating on its inner wall; in the 300-150℃ range, it flows through the second removable metal mineral collection chamber, where silver-, zinc-, and lead-rich polymetallic solid particles are precipitated and collected under the guidance of the coating; the fluid is injected with iron salts and oxidants through the third seawater injection valve, and flows through the second removable metal mineral collection chamber in the range below 150℃, where it reacts, solidifies, and captures precipitates of ferric arsenate and ferric antimonate; The oxidation-reduction potential is adjusted at the third seawater injection valve and a special iron salt is added to oxidize As and Sb and generate insoluble iron arsenate and iron antimonate coprecipitates. The above-mentioned harmful element precipitate particles are captured and retained in the third detachable metal mineral collection chamber. The detoxified wastewater is safely discharged into the sea. Step S4: Underwater disassembly and assembly and sea surface transfer; Continue to control the internal flow rate of the high-efficiency insulated transport pipeline to remain within the preset range. When the solids in each detachable metal mineral collection chamber are enriched to the preset amount, the underwater robot actively disassembles the fully loaded reaction chamber underwater and transports it to the land-based refinery via a transfer ship. At the same time, the underwater robot reassembles and resets the new reaction chamber.

9. The mining method for hydrothermal fluid surface extraction and in-process graded enrichment and sedimentation according to claim 8, characterized in that: In step S2, the outer wall of the high-efficiency insulated transport pipeline is provided with an insulation layer, and the inner wall of the pipeline is coated with polytetrafluoroethylene. Temperature sensors are installed inside the first, second, and third detachable metal mineral collection chambers to adjust the seawater injection flux according to the temperature, thereby realizing a stepped temperature-controlled graded sedimentation process.

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