Pure oxygen oxidation microorganism pressure gold extraction system and method

Abstract

The present application belongs to the technical field of microbial gold extraction, and particularly relates to a pure oxygen oxidation microbial pressure gold extraction system and method; wherein the raw ore supply pump is connected with the pressure oxidation unit, the gas supply device is connected with the pressure oxidation unit and the normal pressure oxidation unit, the pressure oxidation unit is connected with its circulating back material port, and the pressure oxidation unit is also connected with the normal pressure oxidation unit; the normal pressure oxidation unit is connected with its circulating back material port, and the pressure oxidation unit is connected with the gas inlet of the normal pressure oxidation unit; the constant temperature device is connected with the heat exchange interfaces of the pressure oxidation unit and the normal pressure oxidation unit respectively, and is used for controlling the temperature of the oxidation process; the present application combines pressure and normal pressure to improve the oxygen utilization rate, reduces the oxidation slurry volume while not reducing the raw ore processing capacity, reduces the amount of slurry water, avoids the risk of stirring shaft breakage, and realizes the defoaming function of the slurry; the system has high oxidation efficiency, large processing capacity, and is conducive to the industrial actual promotion.

Description

Technical Field

[0001] This invention belongs to the field of microbial gold extraction technology, and specifically relates to a pure oxygen oxidative microbial pressure gold extraction system and method. Background Technology

[0002] Bio-oxidation gold extraction technology utilizes microorganisms in nature. By selecting sulfur- and iron-loving leaching strains and conducting adaptive cultivation and domestication, the microorganisms oxidize and decompose the sulfide ore matrix under suitable conditions through the direct action of their metabolism or the indirect action of their metabolic products. This process destroys harmful components such as pyrite and arsenopyrite that encapsulate the gold, thus fully exposing the gold.

[0003] In this process, the oxidation of sulfides in the oxidation reactor requires a large amount of oxygen. If the oxygen concentration of the gas introduced into the slurry is below 8%, bacterial growth will be inhibited. Therefore, adequate ventilation must be ensured to maintain the dissolved oxygen content in the solution at around 4 mg / L, and uniform air dispersion must be guaranteed within the bioreactor. The optimal temperature range for microbial oxidation to extract gold is 45℃~53℃. Autotrophic bacteria thrive in acidic environments, with an optimal pH of 1.0~1.5, within which their activity is highest.

[0004] Bioreactors typically employ compressed air ring-type perforated pipes for aeration and are equipped with built-in baffle heat exchangers. Combined with compressed air supplied by an air generator and cooling circulating water, these components enable microorganisms to complete the oxidation and gold extraction process in a uniformly aerated slurry.

[0005] The process currently has the following characteristics: the material residence time in oxidation operations is long, generally requiring about 6 days; the slurry concentration in oxidation operations is relatively low, generally 18% to 20%; and the core equipment—the oxidation reactor—has a large volume, with a single tank volume reaching 400 to 900 m³. 3 The oxidation process is energy-intensive, with approximately 120 kW·h of aeration power and 55 kW·h of stirring power per ton of concentrate. Furthermore, bacterial metabolites in the bio-oxidation slag can easily cause foaming, leading to overflow accidents and affecting the continuous and stable operation of the leaching process.

[0006] To address the aforementioned issues, there is an urgent need to develop a novel bio-oxidation gold extraction system that possesses high dissolved oxygen capacity, adapts to high-concentration slurries, and can shorten the oxidation cycle. Summary of the Invention

[0007] To overcome the above problems, the present invention provides a pure oxygen oxidation microbial pressure gold extraction system and method, which is used to achieve high-concentration mineral slurry environmental oxidation gold extraction by microorganisms under certain pressure conditions by introducing high-purity oxygen. At the same time, it serves as a new type of pressure-bearing, circulating homogenizing reactor to meet the requirements of lower carbon, energy saving and high efficiency in the bio-oxidation gold extraction industry.

[0008] A pure oxygen oxidizing microbial pressure gold extraction system includes: a gas supply device, a raw ore supply pump, a pressure oxidation unit, an atmospheric pressure oxidation unit, a first circulation device, a second circulation device, and a constant temperature device.

[0009] The raw ore supply pump is connected to the inlet of the pressure oxidation unit and is used to supply slurry to it;

[0010] The gas supply device is connected to the gas inlets of the pressurized oxidation unit and the atmospheric pressure oxidation unit respectively, and is used to supply the required gas to them;

[0011] The discharge port of the pressure oxidation unit is connected to its own return port through the first circulation device to form a first internal circulation loop. At the same time, the discharge port of the pressure oxidation unit is also connected to the inlet of the atmospheric pressure oxidation unit through a material conveying pipeline.

[0012] The discharge port of the atmospheric pressure oxidation unit is connected to its own return port through the second circulation device to form a second internal circulation loop;

[0013] The gas outlet of the pressure oxidation unit is connected to the gas inlet of the atmospheric pressure oxidation unit through a gas recovery pipeline;

[0014] The constant temperature device is connected to the heat exchange interface of the pressure oxidation unit and the atmospheric pressure oxidation unit respectively, and is used to control the temperature of the oxidation process.

[0015] The gas supply device includes an oxygen storage tank and a carbon dioxide storage tank; wherein the oxygen storage tank and the carbon dioxide storage tank are connected in parallel and are connected to the gas inlet of the pressurized oxidation unit and the atmospheric oxidation unit through a gas supply pipeline, so as to simultaneously supply oxygen and carbon dioxide to the pressurized oxidation unit and the atmospheric oxidation unit.

[0016] Both the gas supply pipeline and the material conveying pipeline are equipped with a regulating and metering system.

[0017] The pressure oxidation unit includes multiple primary pressure oxidizers arranged in parallel; the atmospheric pressure oxidation unit includes multiple secondary atmospheric pressure oxidizers arranged in series.

[0018] The primary pressure oxidizer includes a tank body, which is divided into a gas collection zone, an oxidation zone, and a settling and discharge zone from top to bottom. The tank body containing the gas collection zone is equipped with a feed inlet, a circulating return inlet, a gas outlet, and a defoamer dosing port. The tank body containing the gas collection zone is also equipped with a defoaming spray ring connected to the defoamer dosing port. The tank body containing the oxidation zone is equipped with a gas inlet, a cooling water inlet, and a cooling water outlet. The tank body containing the oxidation zone is also equipped with a jet aerator connected to the gas inlet. The tank body containing the oxidation zone is also equipped with a U-shaped heat exchanger. The cooling water inlet and cooling water outlet are respectively connected to the inlet and outlet of the U-shaped heat exchanger. The part of the tank body containing the settling and discharge zone has a conical structure with a discharge port at the bottom of the cone.

[0019] The bottom of the primary pressure oxidizer is fixed with a support skirt, which is fixed to the bottom of the tank part where the oxidation zone is located, and the tank part where the settling and discharge zone is located is located inside the support skirt.

[0020] The structure of the secondary atmospheric pressure oxidizer is the same as that of the primary pressure oxidizer, except that: the feed inlet of the secondary atmospheric pressure oxidizer is connected to a feed pipe, and the feed pipe extends into the tank where the oxidation zone is located. The upper part of the side wall of the tank where the oxidation zone is located is provided with a material overflow port; when set in series, the material overflow port of the previous secondary atmospheric pressure oxidizer is connected to the feed inlet of the next secondary atmospheric pressure oxidizer.

[0021] The gas outlet of the primary pressure oxidizer and the gas inlet of the corresponding secondary atmospheric pressure oxidizer are connected by gas recovery pipelines.

[0022] It also includes a defoamer dosing machine, which is connected to the defoamer dosing ports of the pressurized oxidation unit and the atmospheric pressure oxidation unit via pipelines.

[0023] Both the first circulation device and the second circulation device are equipped with jacketed tube heat exchangers on their respective circulation pipelines.

[0024] The beneficial effects of this invention are:

[0025] The pressurized pure oxygen oxidation reactor microbial oxidation gold extraction system of this invention increases the dissolved oxygen content per unit volume of slurry under a certain pressure. The combination of pressurized and atmospheric pressure improves oxygen utilization, reduces the amount of gas aeration in the oxidizer, and relatively increases the slurry throughput. Simultaneously, it increases the slurry oxidation concentration, reducing the volume of oxidized slurry without decreasing the raw ore throughput, thus reducing the amount of conditioning water used. Jet aeration combined with a circulating pump for homogenization replaces the traditional mechanical agitator, avoiding the risk of shaft breakage, and also achieves preliminary defoaming of the slurry. This system has high oxidation efficiency and large throughput, making it suitable for practical industrial application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 This is a supplementary structural diagram of the present invention.

[0029] Figure 3 This is a schematic diagram of the structure of the first-stage pressure oxidizer of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the two-stage atmospheric pressure oxidizer of the present invention.

[0031] Figure 5 This is a diagram showing the liquid supply path of the constant temperature machine of the present invention.

[0032] Wherein: 1—Gas supply device; 2—Raw ore supply pump; 3—First-stage pressure oxidizer; 4—Second-stage atmospheric pressure oxidizer; 5—First-stage circulation pump; 6—Second-stage circulation pump; 7—Thermostat; 8—Defoamer dosing machine; 9—Jacketed tube heat exchanger; 10—Regulation and metering system;

[0033] 11—Oxygen generator; 12—Oxygen storage tank; 13—Carbon dioxide storage tank;

[0034] 31—First-stage pressure oxidizer one; 32—First-stage pressure oxidizer two; 33—First-stage pressure oxidizer three;

[0035] 41—Secondary atmospheric pressure oxidizer one; 42—Secondary atmospheric pressure oxidizer two; 43—Secondary atmospheric pressure oxidizer three;

[0036] 51—First-stage circulating pump one; 52—First-stage circulating pump two; 53—First-stage circulating pump three;

[0037] 61—Secondary circulation pump one; 62—Secondary circulation pump two; 63—Secondary circulation pump three;

[0038] 71—Level 1 constant temperature machine; 72—Level 2 constant temperature machine;

[0039] 311—Gas collection zone; 312—Oxidation zone; 313—Settling and discharge zone; 314—Support skirt; 315—Defoaming spray ring; 316—U-shaped heat exchanger; 317—Jet aerator;

[0040] a—Inlet; a-1—Inlet pipe; b—Discharge port; c—Circulation return port; d—Gas inlet; e—Gas outlet; f—Cooling water inlet; g—Cooling water outlet; h—Defoamer dosing port; i—Maintenance inlet; j—Material overflow port. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0042] Example:

[0043] Please see Figures 1 to 5 As shown, this invention utilizes high-purity oxygen under certain pressure conditions to achieve high-concentration mineral slurry environmental oxidation for gold extraction by microorganisms. Simultaneously, this invention develops a novel pressurized, circulating homogenized reactor to meet the requirements of a more low-carbon, energy-efficient, and high-performance bio-oxidation gold extraction industry.

[0044] The present invention provides a pure oxygen oxidation microbial pressure gold extraction system, comprising a gas supply device 1, a raw ore supply pump 2, a pressure oxidation unit, an atmospheric pressure oxidation unit, a first circulation device, a second circulation device, a constant temperature device, an antifoaming agent dosing machine 8, a jacketed tube heat exchanger 9, and a regulating and metering system 10.

[0045] The first circulation device is a primary circulation pump 5, the second circulation device is a secondary circulation pump 6, and the temperature control device is a temperature control machine 7.

[0046] The gas supply device 1 includes an oxygen generator 11, an oxygen storage tank 12, and a carbon dioxide storage tank 13, wherein the oxygen generator 11 is connected to the oxygen storage tank 12 and provides oxygen to the oxygen storage tank 12.

[0047] The pressure oxidation unit consists of three primary pressure oxidizers 3, namely, primary pressure oxidizer one 31, primary pressure oxidizer two 32, and primary pressure oxidizer three 33. These three primary pressure oxidizers 3 are connected in parallel, that is, the raw ore supply pump 2 is connected to the inlet a of primary pressure oxidizer one 31, primary pressure oxidizer two 32, and primary pressure oxidizer three 33 through pipelines, and can feed slurry to each primary pressure oxidizer 3 respectively.

[0048] The primary pressure oxidizer 3 includes a tank body and a supporting skirt 314. The tank body of the primary pressure oxidizer 3 is fixed on the supporting skirt 314. The tank body is divided into a gas collection zone 311, an oxidation zone 312, and a settling and discharge zone 313 from top to bottom. The tank body containing the gas collection zone 311 has a built-in defoaming spray ring 315, and the tank body containing the gas collection zone 311 has a circulating return port c, a gas outlet e, and a defoamer dosing port h, wherein the defoamer dosing port h is connected to the defoaming spray ring 315. The tank body containing the oxidation zone 312 has two built-in U-shaped heat exchangers 316 and a jet aerator 317, and the... The tank containing the oxidation zone 312 has a feed inlet a, a gas inlet d, two cooling water inlets f, two cooling water outlets g, and a maintenance inlet i. The gas inlet d is connected to the air inlet of the jet aerator 317, and the inlets and outlets of the two U-shaped heat exchangers 316 are connected to the corresponding cooling water inlets f and cooling water outlets g, respectively. The tank containing the settling and discharge zone 313 has a conical design and a discharge port b at the bottom. The discharge port b includes a vertical pipe and a horizontal pipe. One end of the vertical pipe is connected to the bottom opening of the settling and discharge zone 313, and the other end is connected to the horizontal pipe. The end of the horizontal pipe extends out of the support skirt 314.

[0049] The atmospheric pressure oxidation unit consists of three secondary atmospheric pressure oxidizers 4, namely, secondary atmospheric pressure oxidizer one 41, secondary atmospheric pressure oxidizer two 42, and secondary atmospheric pressure oxidizer three 43. The structure of the secondary atmospheric pressure oxidizers 4 is the same as that of the primary pressure oxidizer 3, except that: a feed pipe a-1 is connected to the feed inlet a of the secondary atmospheric pressure oxidizer 4, and the feed pipe a-1 extends into the tank where the oxidation zone 312 is located. A material overflow port j is opened on the upper part of the side wall of the tank where the oxidation zone 312 is located. The three secondary atmospheric pressure oxidizers 4 are connected in series, that is, the material overflow port j of the secondary atmospheric pressure oxidizer one 41 is connected to the feed inlet a of the secondary atmospheric pressure oxidizer two 42, and the material overflow port j of the secondary atmospheric pressure oxidizer two 42 is connected to the feed inlet a of the secondary atmospheric pressure oxidizer three 43.

[0050] The feed pipe a-1 connected to the feed port a on the secondary atmospheric pressure oxidizer 4 extends into the tank where the oxidation zone 312 is located, and at the same time, a material overflow port j is opened at a certain height on the side wall of the tank where the oxidation zone 312 is located.

[0051] In summary, the oxygen generator 11 is connected to the oxygen storage tank 12 via pipelines, and the outlet of the oxygen storage tank 12 is connected to the gas inlet d of each primary pressure oxidizer 3 via the regulating metering system 10; the outlet of the carbon dioxide storage tank 13 is also connected to the gas inlet d of each primary pressure oxidizer 3 via the regulating metering system 10.

[0052] The outlet of the oxygen storage tank 12 is also connected to the gas inlet d of each secondary atmospheric pressure oxidizer 4 through the regulating metering system 10; the outlet of the carbon dioxide storage tank 13 is also connected to the gas inlet d of each secondary atmospheric pressure oxidizer 4 through the regulating metering system 10.

[0053] The raw ore supply pump 2 is connected to the feed inlet a of multiple primary pressure oxidizers 3 via pipelines.

[0054] The discharge port b of the first-stage pressure oxidizer 31 is connected to its own return port c through the first-stage circulation pump 51; the discharge port b of the second-stage pressure oxidizer 32 is connected to its own return port c through the second-stage circulation pump 52; and the discharge port b of the third-stage pressure oxidizer 33 is connected to its own return port c through the third-stage circulation pump 53.

[0055] The connection method of each primary circulation pump 5 is as follows: the feed end of the primary circulation pump 5 is connected to the discharge port b through a pipeline, the discharge end is connected to one end of the inner tube of the jacketed tube heat exchanger 9 through a pipeline, the other end of the inner tube of the jacketed tube heat exchanger 9 is connected to the circulation return port c through a pipeline, and the outer tube of the jacketed tube heat exchanger 9 is connected to the cooling water supply system, which is used to supply cooling water to the outer tube of the jacketed tube heat exchanger 9.

[0056] The discharge end of each primary circulating pump 5 is also connected to the feed pipe a-1 of the secondary atmospheric pressure oxidizer 41 through a material conveying pipeline, and each material conveying pipeline is equipped with an adjustment and metering system 10.

[0057] The gas outlet e of the first-stage pressure oxidizer 31 is connected to the gas inlet d of the second-stage atmospheric pressure oxidizer 43 via a pipeline. The gas outlet e of the first-stage pressure oxidizer 32 is connected to the gas inlet d of the second-stage atmospheric pressure oxidizer 42 via a pipeline. The gas outlet e of the first-stage pressure oxidizer 33 is connected to the gas inlet d of the second-stage atmospheric pressure oxidizer 41 via a pipeline.

[0058] The discharge port b of the first secondary atmospheric pressure oxidizer 41 is connected to its own return port c through the second secondary circulation pump 61. The discharge port b of the second secondary atmospheric pressure oxidizer 42 is connected to its own return port c through the second secondary circulation pump 62. The discharge port b of the third secondary atmospheric pressure oxidizer 43 is connected to its own return port c through the second secondary circulation pump 63.

[0059] The connection method of each secondary circulation pump 6 is as follows: one end of the secondary circulation pump 6 is connected to the discharge port b through a pipeline, and the other end is connected to one end of the inner tube of the jacketed tube heat exchanger 9 through a pipeline. The other end of the inner tube of the jacketed tube heat exchanger 9 is connected to the circulation return port c through a pipeline. The outer tube of the jacketed tube heat exchanger 9 is connected to the cooling water supply system, which is used to supply cooling water to the outer tube of the jacketed tube heat exchanger 9.

[0060] The gas outlet e of the secondary atmospheric pressure oxidizer 4 is connected to the atmosphere.

[0061] The outlet of the secondary constant temperature unit 72 is connected to the cooling water inlet f of each primary pressure oxidizer 3 through a pipeline, and the return water outlet of the secondary constant temperature unit 72 is connected to the cooling water outlet g of each primary pressure oxidizer 3 through a pipeline.

[0062] The outlet of the primary constant temperature unit 71 is connected to the cooling water inlet f of each secondary atmospheric pressure oxidizer 4 through a pipeline, and the return water outlet of the primary constant temperature unit 71 is connected to the cooling water outlet g of each secondary atmospheric pressure oxidizer 4 through a pipeline.

[0063] The defoamer dosing machine 8 is connected to the defoamer dosing port h of the pressurized oxidation unit and the atmospheric pressure oxidation unit through pipelines.

[0064] The working pressure of the pressure oxidation unit is 0.1MPa to 1MPa, the volume concentration of oxygen in the total gas is above 90%, the concentration of the treated slurry is above 30%, and the oxidation time is about 4 days. The combination of primary pressure and secondary atmospheric pressure improves the utilization rate of oxygen and carbon dioxide gas, and the circulation homogenization replaces the traditional mechanical stirring to reduce costs and make the operation more stable.

[0065] The regulating and metering system 10 installed on the gas supply pipeline includes a liquid pump and a liquid flow meter, both of which are installed on the gas supply pipeline.

[0066] The regulating and metering system 10 installed on the material conveying pipeline includes a gas conveying pump and a gas flow meter, both of which are installed on the material conveying pipeline.

[0067] Working process of this invention:

[0068] The feed end of the raw ore supply pump 2 is connected to the slurry to be oxidized. The raw ore supply pump 2 is started, and the slurry to be oxidized is simultaneously supplied to the three parallel primary pressure oxidizers 3. When the slurry level in each primary pressure oxidizer 3 reaches a certain requirement, the primary circulation pump 5 is started to realize the self-circulation homogenization of the primary pressure oxidizer 3 to prevent ore sedimentation. At the same time, the oxygen generator 11 of the gas supply device 1 is started, and oxygen enters the oxygen storage tank 12 to maintain stable oxygen supply. The oxygen storage tank 12 and the carbon dioxide storage tank 13 are connected to the regulating and metering system 10 through pipelines. Through the gas inlet d and the jet aerator 317, oxygen and carbon dioxide gas are first supplied to the primary pressure oxidizer 3. When the slurry in the primary pressure oxidizer 3 reaches the maximum load line marked on the oxidation zone.

[0069] The regulating and metering system 10 at the discharge end of the primary circulation pump 5 is activated, allowing the slurry that has completed primary oxidation to enter the secondary atmospheric oxidizer 4 for continuous oxidation. At this time, each secondary circulation pump 6 is started, realizing the homogenization and self-circulation of the secondary atmospheric oxidizer 4. The oxygen storage tank 12 and the carbon dioxide storage tank 13 are connected to the regulating and metering system 10 through pipelines, and oxygen and carbon dioxide are supplied to the secondary atmospheric oxidizer 4 through the gas inlet d and the jet aerator 317. In order to prolong the secondary atmospheric oxidation time, after the slurry in the secondary atmospheric oxidizer 1 41 reaches the overflow surface, it flows out through the material overflow port j and enters the secondary atmospheric oxidizer 2 42 for oxidation. At the same time, the excess oxygen that has not participated in the oxidation reaction is discharged from the gas outlet e at the top of the primary pressure oxidizer 3 and enters the corresponding secondary atmospheric oxidizer 4 to participate in the secondary atmospheric oxidation reaction. The gas after participating in the secondary atmospheric oxidation reaction is directly discharged into the atmosphere through the gas outlet e of each secondary atmospheric oxidizer 4. The slurry that has completed the oxidation work in the secondary atmospheric oxidizer 3 43 connected in series at the end is discharged through the material overflow port j.

[0070] During the oxidation process described above, if the internal temperature of the oxidizer becomes too high, the corresponding thermostat 7 will be activated, and heat will be exchanged with the primary pressure oxidizer 3 or the secondary atmospheric pressure oxidizer 4 through the pipeline via the cooling water inlet f, U-shaped heat exchanger 316, and cooling water outlet g. At the same time, the jacketed tube heat exchanger 9 can also be activated for circulating homogenized slurry pipeline heat exchange; while the primary circulation pump 5 and the secondary circulation pump 6 are circulating and homogenizing, defoaming can also be performed on the liquid surface inside the primary pressure oxidizer 3 and the secondary atmospheric pressure oxidizer 4. If the amount of foam generated is large, the defoamer dosing machine 8 will be activated, and deep defoaming operations inside the oxidizer will be completed through the defoamer dosing port h and the defoaming spray ring 315.

[0071] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the scope of protection of the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, any person skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention. These simple modifications are all within the scope of protection of the present invention.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0073] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A pure oxygen oxidation microorganism pressure gold extraction system, characterized in that, include: Gas supply device, raw ore supply pump, pressurized oxidation unit, atmospheric pressure oxidation unit, first circulation device, second circulation device, and constant temperature device; The raw ore supply pump is connected to the inlet of the pressure oxidation unit and is used to supply slurry to it; The gas supply device is connected to the gas inlets of the pressurized oxidation unit and the atmospheric pressure oxidation unit respectively, and is used to supply the required gas to them; The discharge port of the pressure oxidation unit is connected to its own return port through the first circulation device to form a first internal circulation loop. At the same time, the discharge port of the pressure oxidation unit is also connected to the inlet of the atmospheric pressure oxidation unit through a material conveying pipeline. The discharge port of the atmospheric pressure oxidation unit is connected to its own return port through the second circulation device to form a second internal circulation loop; The gas outlet of the pressure oxidation unit is connected to the gas inlet of the atmospheric pressure oxidation unit through a gas recovery pipeline; The constant temperature device is connected to the heat exchange interface of the pressure oxidation unit and the atmospheric pressure oxidation unit respectively, and is used to control the temperature of the oxidation process; The gas supply device includes an oxygen storage tank and a carbon dioxide storage tank; wherein the oxygen storage tank and the carbon dioxide storage tank are connected in parallel and are connected to the gas inlet of the pressurized oxidation unit and the atmospheric oxidation unit through a gas supply pipeline, so as to simultaneously supply oxygen and carbon dioxide to the pressurized oxidation unit and the atmospheric oxidation unit. The pressure oxidation unit includes multiple primary pressure oxidizers arranged in parallel; the atmospheric pressure oxidation unit includes multiple secondary atmospheric pressure oxidizers arranged in series. The primary pressure oxidizer includes a tank body, which is divided into a gas collection zone, an oxidation zone, and a settling and discharge zone from top to bottom. The tank body containing the gas collection zone is equipped with a feed inlet, a circulating return inlet, a gas outlet, and a defoamer dosing port. The tank body containing the gas collection zone is also equipped with a defoaming spray ring connected to the defoamer dosing port. The tank body containing the oxidation zone is equipped with a gas inlet, a cooling water inlet, and a cooling water outlet. The tank body containing the oxidation zone is also equipped with a jet aerator connected to the gas inlet. The tank body containing the oxidation zone is also equipped with a U-shaped heat exchanger. The cooling water inlet and cooling water outlet are respectively connected to the inlet and outlet of the U-shaped heat exchanger. The part of the tank body containing the settling and discharge zone has a conical structure with a discharge port at the bottom of the cone.

2. The system for pressure oxidation of pure oxygen-oxidizing microorganisms according to claim 1, characterized in that, Both the gas supply pipeline and the material conveying pipeline are equipped with a regulating and metering system.

3. The system for pressure oxidation of pure oxygen-oxidizing microorganisms according to claim 1, characterized in that, The bottom of the primary pressure oxidizer is fixed with a support skirt, which is fixed to the bottom of the tank part where the oxidation zone is located, and the tank part where the settling and discharge zone is located is located inside the support skirt.

4. The pure oxygen oxidative microbial pressure gold extraction system according to claim 1, characterized in that, The structure of the secondary atmospheric pressure oxidizer is the same as that of the primary pressure oxidizer, except that: the feed inlet of the secondary atmospheric pressure oxidizer is connected to a feed pipe, and the feed pipe extends into the tank where the oxidation zone is located. The upper part of the side wall of the tank where the oxidation zone is located is provided with a material overflow port; when set in series, the material overflow port of the previous secondary atmospheric pressure oxidizer is connected to the feed inlet of the next secondary atmospheric pressure oxidizer.

5. The pure oxygen oxidative microbial pressure gold extraction system according to claim 1, characterized in that, The gas outlet of the primary pressure oxidizer and the gas inlet of the corresponding secondary atmospheric pressure oxidizer are connected by gas recovery pipelines.

6. The pure oxygen oxidative microbial pressure gold extraction system according to claim 1, characterized in that, It also includes a defoamer dosing machine, which is connected to the defoamer dosing ports of the pressurized oxidation unit and the atmospheric pressure oxidation unit respectively via pipelines; Both the first circulation device and the second circulation device are equipped with jacketed tube heat exchangers on their respective circulation pipelines.

7. A method for gold extraction using the pure oxygen oxidizing microbial pressure gold extraction system according to any one of claims 1-6, comprising the following: S1: Material Preparation Stage Start the raw ore supply pump to supply the slurry to be oxidized to the pressure oxidation unit; when the slurry level reaches the preset requirement, start each first circulation device to realize the self-circulation and homogenization of the slurry in the pressure oxidation unit and prevent sedimentation. S2: Oxidation treatment stage Gas from oxygen and carbon dioxide storage tanks is supplied to the pressurized oxidation unit to achieve primary oxidation of the slurry. When the slurry volume in the pressurized oxidation unit reaches the maximum oxidation load, the regulating and metering system between the first circulation device and the atmospheric oxidation unit is activated so that the slurry that has completed primary oxidation enters the atmospheric oxidation unit for continuous oxidation. At the same time, the second circulation device is started to realize the self-circulation and homogenization of the slurry in the atmospheric oxidation unit, and to supplement the atmospheric oxidation unit with oxygen and carbon dioxide gas. In addition, the unreacted oxygen discharged from the pressurized oxidation unit is guided to the atmospheric oxidation unit as supplementary gas to participate in the secondary atmospheric oxidation reaction; the gas after participating in the secondary atmospheric oxidation reaction is directly discharged into the atmosphere; the slurry that has completed the oxidation process in the atmospheric oxidation unit is discharged through its material overflow port. Perform at least one of the following control operations based on temperature and foam conditions: Temperature control: When the internal temperature of any oxidation unit is too high, the corresponding constant temperature device is activated, and the cooling medium is circulated and supplied to the U-shaped heat exchanger in the pressurized oxidation unit or the atmospheric pressure oxidation unit for heat exchange; at the same time, the jacketed tube heat exchanger is activated to cool down the slurry pipeline in the circulating homogenization. Defoaming control: Start the defoamer dosing machine to defoam the interior of the corresponding oxidation unit through the defoamer dosing port and the defoaming spray ring.

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