A pretreatment device and process for arsenic-containing high-sulfur gold ore

Abstract

This invention relates to the field of hydrometallurgical technology, specifically to a pretreatment device and process for arsenic-containing high-sulfur gold ore. The device includes a pretreatment unit for oxidizing the ore slurry; a water treatment unit for purifying and circulating water; and a gas treatment unit for catalyzing ozone. The pretreatment unit includes an ozone generator connected to a reaction tank via a pipeline. Multiple ultrasonic transducers are arrayed on the outer wall of the reaction tank. This invention utilizes a combination of ozone, positive pressure, and ultrasonic vibration in the pretreatment unit. Pressurization increases the ozone solubility, and ultrasonic cavitation effectively enhances oxidation efficiency, thereby reducing pretreatment time. Combined with the water treatment and gas treatment units, no polluting waste liquid or gas is generated, effectively avoiding environmental pollution. Increased ozone utilization directly reduces oxygen and electricity consumption, and wastewater recycling significantly reduces fresh water consumption and acid usage.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, specifically to a pretreatment device and process for arsenic-containing high-sulfur gold ore. Background Technology

[0002] In arsenic-containing high-sulfur gold ores, gold minerals are often embedded in arsenopyrite and pyrite in the form of fine particles. In oxygen-containing water media, the surface of arsenopyrite is more easily oxidized to form compounds such as FeAs2O4, which leads to passivation of the ore surface and a significant decrease in its floatability, thus affecting the gold flotation recovery rate.

[0003] Existing methods for improving gold flotation recovery involve oxidation pretreatment, specifically roasting and pressurized alkaline leaching. Roasting is a traditional and effective oxidation pretreatment process, but it is highly polluting and incurs significant environmental costs. Pressurized alkaline leaching is a common and effective process for pretreating arsenic- and sulfur-containing, refractory gold ores, but it requires heating and pressurization, placing stringent demands on equipment, making operation difficult, and consuming large amounts of sodium hydroxide, resulting in high production costs. This hinders the industrialization and widespread adoption of this process.

[0004] In view of this, we propose a pretreatment device and process for arsenic-containing high-sulfur gold ore. Summary of the Invention

[0005] The purpose of this invention is to provide a pretreatment device and process for arsenic-containing high-sulfur gold ore, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A pretreatment device for arsenic-containing high-sulfur gold ore, comprising, A pretreatment unit is used to oxidize the slurry; Water treatment facilities are used to purify and recycle water; Gas processing equipment used for ozone catalysis; The pretreatment unit includes an ozone generator, which is connected to a reaction vessel via a pipe. Multiple ultrasonic transducers are arrayed on the outer wall of the reaction vessel, and an air pump is connected to the top of the reaction vessel via a pipe.

[0007] Preferably, the reaction vessel is a sealed vessel, with a feed inlet and a water inlet fixedly installed on it. The reaction vessel is connected to a thickener via a pipeline, and the thickener is connected to a filter press via a pipeline.

[0008] Preferably, the water treatment mechanism includes a multi-stage sedimentation tank, which is connected to a filter press via a pipeline. A return pipe is fixedly connected to the filter press, and the return pipe is connected to the inlet via a pipeline.

[0009] Preferably, the gas processing device includes a gas-liquid separator, which is connected to a gas pump via a pipeline, and the gas-liquid separator is connected to a decomposition tower via a pipeline.

[0010] This invention also provides a pretreatment process for arsenic-containing high-sulfur gold ore, comprising the following steps: Step 1: Slurry preparation. After crushing and grinding the ore, it is mixed with circulating water and acid. The pH of the slurry after mixing is between 1.5 and 2.5, forming a homogeneous slurry. Step 2: Reaction. The homogeneous slurry is added to the reaction vessel. Ozone is introduced into the reaction vessel under positive pressure, and ultrasound is applied at the same time. The slurry is left to stand for 2-4 hours. Under the synergistic effect of ultrasonic cavitation, the ozone is efficiently converted into hydroxyl radicals, achieving deep and rapid oxidation of sulfide minerals. Step 3: Exhaust gas treatment. After step 2 is completed, the ozone supply is stopped, and the reaction tank gradually enters a negative pressure state. The exhaust gas enters the gas-liquid separator, and the separated gas is sent to the decomposition tower to completely decompose the residual ozone into oxygen before being safely discharged. Step 4: Washing and solid-liquid separation, depressurization, and oxidation of the slurry. The slurry is then fed into a thickener, where recycled water is used to wash the slag, recover solubles, and reduce acidity. The washed slurry is then filtered through a filter press to obtain pretreated concentrate and acidic washing liquid. Step 5: Wastewater treatment and recycling. 20%-30% of the acidic washing liquid enters a multi-stage sedimentation tank for neutralization and sedimentation, while 70%-80% of the acidic washing liquid is directly returned to Step 1 as acid for recycling. The supernatant after sedimentation in the multi-stage sedimentation tank is returned to the washing process in Step 4 as process water.

[0011] Preferably, in step one, the proportion of mineral particles smaller than 74 μm in the mineral sample exceeds 85%, the acid is sulfuric acid solution, and the solid content of the slurry is 15-40%.

[0012] Preferably, in step two, the positive pressure is 0.12-0.30 MPa, the ultrasonic power density is 50-300 W / L, the temperature is controlled at 20-50℃, and ozone is introduced at a constant concentration of 80-150 g / Nm³.

[0013] Preferably, in step five, the neutralization and precipitation utilizes lime slurry or alkaline solution, with a maximum pH of 8-10 in the multi-stage sedimentation tank, at normal temperature and pressure.

[0014] Preferably, in step three, the decomposition tower contains a catalyst, MnO2-CuO or Al2O3, and the catalytic temperature is 80-120℃.

[0015] By employing the above technical solution, the present invention provides a pretreatment device for arsenic-containing high-sulfur gold ore, which has at least the following beneficial effects: (1) The present invention utilizes ozone, positive pressure and ultrasonic vibration in a pretreatment mechanism to increase the ozone solubility rate by pressurization. Combined with ultrasonic cavitation, it can effectively enhance the oxidation efficiency, thereby reducing the pretreatment time. In addition, with the water treatment mechanism and gas treatment mechanism, no polluting waste liquid or waste gas is generated, which can effectively avoid environmental pollution. The increased ozone utilization rate can directly reduce oxygen consumption and power consumption. Wastewater recycling greatly reduces the consumption of fresh water and acid usage.

[0016] (2) The present invention uses a pretreatment mechanism in conjunction with a tail gas treatment mechanism, and monitors the amount of ozone discharged to provide feedback on the amount of ozone added. This enables precise and dynamic addition of ozone, and can automatically adapt to different ores, effectively improving the applicability of the device. By using a pretreatment mechanism in conjunction with a water treatment mechanism, the acidic washing liquid of the thickener is partially recycled and partially precipitated, so that the recycled acidic washing liquid is in a dynamic equilibrium state, avoiding the accumulation of impurities that affect the oxidation operation, thus saving costs and ensuring oxidation efficiency.

[0017] (3) By setting up a pretreatment mechanism, a water treatment mechanism and a gas treatment mechanism, the overall equipment modification and upgrade cost of this invention is low. The pressure inside the reaction tank is 0.12-0.30 MPa, which is low and can effectively reduce the material cost of the reaction tank. In addition, since the reaction produces a large amount of oxygen, the cost of maintaining positive pressure inside the reaction tank is reduced. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention, form part of this application: Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] In the diagram: 100, pretreatment unit; 200, water treatment unit; 300, gas treatment unit; 101. Ozone generator; 102. Reaction vessel; 103. Ultrasonic transducer; 104. Air pump; 105. Feed inlet; 106. Water inlet; 107. Thickener; 108. Filter press; 201. Multistage sedimentation tank; 202. Return pipe; 301. Gas-liquid separator; 302. Decomposition tower. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 A pretreatment device for arsenic-containing high-sulfur gold ore includes a pretreatment unit 100 for oxidizing the surface of gold-loaded sulfide minerals, thereby destroying the passivation layer on the mineral surface and improving the gold recovery material from flotation of gold-loaded sulfide minerals.

[0022] Please see Figure 1 The pretreatment unit 100 includes an ozone generator 101, which can use oxygen as a raw material to generate ozone gas. The ozone gas can be used directly as an oxidant or decomposed in an acidic solvent environment to generate free radicals for oxidation. The direct mechanism of ozone gas action on styrax is as follows: first step: Step Two: Step 3: FeAsO4 precipitation is an environmentally friendly form of solidified arsenic.

[0023] On the other hand, the oxidation mechanism of sulfide ions in pyrite by ozone gas is as follows: Furthermore, the free radicals produced by the decomposition of ozone gas are hydroxyl radicals.

[0024] Based on this, the ozone generator 101 is connected to the reaction tank 102 via pipes and valves. The reaction tank 102 is a closed container, which allows for control of the reaction pressure and collection and treatment of the generated gases. The reaction tank 102 is fixedly connected to a feed inlet 105 and a water inlet 106. The feed inlet 105 is used for feeding the slurry, and the water inlet 106 is used to adjust the concentration and acidity of the slurry. Both the feed inlet 105 and the water inlet 106 are equipped with valves to control the feeding rate and ensure a tight seal. Ultrasonic transducers 103 are arrayed around the surface of the reaction tank 102, providing stable ultrasonic vibration to the slurry inside, thereby achieving cavitation, breaking ozone bubbles into micro- and nano-bubbles, and generating strong turbulence and micro-jets, thus directly improving the mass transfer rate and ozone decomposition efficiency.

[0025] Furthermore, an air pump 104 is connected to the top of the reaction vessel 102 via a pipe. The air pump 104 can regulate the pressure inside the reaction vessel 102. By pressurizing the reaction vessel 102 before the reaction, the solubility of ozone in water can be significantly increased, thereby increasing the ozone content in the slurry and improving the contact between ozone and the minerals, thus increasing the oxidation rate. During the reaction, a pressure sensor maintains the air pressure inside the reaction vessel 102 within a stable range, thereby maintaining the stability of the reaction and the reaction vessel 102.

[0026] It is important to note that the bottom of the reaction vessel 102 is equipped with multiple microporous aeration heads for efficient and uniform ozone aeration. Combined with ultrasound, this allows for rapid and uniform distribution of ozone within the slurry, increasing the oxidation reaction rate. Furthermore, an ozone concentration monitor is installed at the outlet of the air pump 104 in the reaction vessel 102 to monitor the ozone concentration in the discharged gas in real time. This real-time ozone concentration monitoring is fed back to the ozone generator 101 via a PLC to adjust the ozone aeration rate, thereby ensuring a dynamic balance between the ozone addition and the reaction rate.

[0027] In addition, the reaction vessel 102 is connected to a thickener 107 via a pipeline. After the reaction is completed, the oxidized slurry can be transported to the thickener 107 for washing and thickening. The washing water is recycled water for subsequent processes, and the washing water and slurry are in a countercurrent state, which accelerates the washing efficiency. The circulating water is neutral or weakly alkaline, and the circulating water washing can effectively separate soluble sulfates, ferric arsenate, and other oxidation products and residual acids from the slag.

[0028] The thickener 107 is connected to the filter press 108 via a pipeline. The washed and purified slurry is transported to the filter press 108 through the pipeline. The filter press 108 further achieves solid-liquid separation, separating the washing filtrate from the ore, which facilitates subsequent ore flotation and wastewater treatment.

[0029] Please see Figure 1 A pretreatment device for arsenic-containing high-sulfur gold ore also includes a water treatment unit 200 and a gas treatment unit 300. The water treatment unit 200 is used for wastewater treatment and water recycling, and the gas treatment unit 300 is used for monitoring and treating ozone in the emitted gas to prevent excessive emissions from affecting the environment.

[0030] The water treatment unit 200 includes a multi-stage sedimentation tank 201 and a return pipe 202. The multi-stage sedimentation tank 201 is used to treat and recycle wastewater from the thickener 107 and filter press 108. During treatment, lime slurry or alkaline solution is added to adjust the pH of the wastewater to 8-10, causing heavy metal ions such as iron, arsenic, and copper in the solution to precipitate as hydroxides or calcium arsenate. The clear water on the upper layer after sedimentation can be returned to the reaction tank 102 or the thickener 107 for recycling as circulating process water. The return pipe 202 can pump the acidic washing liquid from the filter press 108 back to the reaction tank 102 for recycling, reducing the consumption of sulfuric acid and fresh water.

[0031] The gas treatment unit 300 includes a gas-liquid separator 301, which is fixedly connected to the gas pump 104 via a pipeline. This allows the exhaust gas in the reaction tank 102 to be discharged as liquid before being released. The discharged liquid is then transported through a pipeline to a multi-stage sedimentation tank 201 for further treatment. The gas-liquid separator 301 is connected to a decomposition tower 302 via a pipeline for high-temperature catalytic decomposition of ozone in the exhaust gas, thus preventing environmental pollution.

[0032] A pretreatment process for arsenic-containing high-sulfur gold ore includes the following steps: Step 1: Slurry preparation. After crushing and grinding the ore, more than 85% of the mineral particles are below -74 μm. The mineral powder is mixed with circulating water, sulfuric acid, and fresh water. After mixing, the pH of the slurry is controlled between 1.5 and 2.5 to form a uniform slurry. The use of circulating water can effectively reduce the amount of sulfuric acid used and save costs. Step 2: Reaction. A homogeneous slurry is added to reaction tank 102. The internal pressure of reaction tank 102 is controlled between 0.12-0.30 MPa by air pump 104. Ozone at a concentration of 80-150 g / Nm³ is introduced into reaction tank 102 through ozone generator 101. The ozone is evenly introduced into the slurry through microporous aeration heads. Combined with ultrasonic vibration and positive pressure by ultrasonic transducer 103, this effectively improves the solubility and reaction rate of ozone. Furthermore, an ozone concentration monitor is installed at the outlet of air pump 104 in reaction tank 102 to monitor the ozone concentration of the discharged gas in real time. The real-time ozone concentration monitoring is fed back to ozone generator 101 via PLC to adjust the ozone aeration rate, thereby ensuring a dynamic balance between the amount of ozone added and the reaction rate. This maintains a certain concentration of ozone participating in the reaction within the slurry.

[0033] The slurry remains in the reaction tank 102 for 2-4 hours, allowing ozone to be efficiently converted into hydroxyl radicals under the synergistic effect of ultrasonic cavitation and positive pressure, achieving deep and rapid oxidation of sulfide minerals. Another part directly participates in the oxidation of the slurry, exposing the gold ore and improving the subsequent flotation rate of the gold ore.

[0034] Step 3: Exhaust Gas Treatment. After Step 2, ozone supply is stopped. Gas is drawn out using pump 104, gradually creating a negative pressure within reaction tank 102, thus drawing all the exhaust gas into gas-liquid separator 301 for gas-liquid separation. The separated gas is then sent to decomposition tower 302, where residual ozone is completely decomposed into oxygen at 80-120℃ using a MnO2-CuO or Al2O3 catalyst before safe discharge without pollution. The extracted liquid is piped to multi-stage sedimentation tank 201 for sedimentation.

[0035] Step 4: Washing and solid-liquid separation, depressurization, and then pumping the oxidized slurry into thickener 107. The reaction tank 102 is flushed with circulating water, and the flushing water is also pumped into thickener 107. In thickener 107, the supernatant water from the subsequent multi-stage sedimentation tank 201 is used to wash the slag, recover soluble substances, and reduce acidity. The washed slurry is then filtered by filter press 108 to obtain pretreated concentrate and acidic washing liquid. The pretreated concentrate proceeds to the next flotation operation.

[0036] Step 5: Wastewater treatment and recycling. 20%-30% of the acidic washing liquid is pumped into the multi-stage sedimentation tank 201. Heavy metals such as iron and arsenic are precipitated by adding lime milk or alkaline solution. The supernatant after multi-stage sedimentation is neutral or weakly alkaline and can be returned to the washing process in Step 4 for reuse as process water. 70%-80% of the acidic washing liquid is directly returned to Step 1 as circulating water, which can effectively reduce the amount of sulfuric acid and water used and save costs.

[0037] Example 1 This embodiment processes a high-arsenic-sulfur gold concentrate with a gold grade of 35.2 g / t, an arsenic content of 9.5%, and a sulfur content of 25.0%.

[0038] The processing steps are as follows: Slurry preparation: The ore sample was ground to a fineness of -74 μm (92%). A 75% circulating acidic washing solution and 25% fresh water were used, and sulfuric acid was added to adjust the slurry pH to 2.0, controlling the slurry solids content to 30%.

[0039] Reaction: The slurry is pumped into reaction vessel 102. The pressure inside the vessel is maintained at 0.25 MPa using air pump 104. The ultrasonic transducer 103 is turned on, and the power density is set to 200 W / L. Ozone at a concentration of 120 g / Nm³ is introduced, and the reaction temperature is controlled at 40℃. The reaction time is set to 2.5 hours, and dynamic equilibrium is achieved using ozone concentration monitoring and a PLC.

[0040] Tail gas treatment: After the reaction is completed, the tail gas is separated into gas and liquid and enters the decomposition tower 302 filled with MnO2-CuO / Al2O3 catalyst, where it is completely decomposed at 100℃.

[0041] Washing and solid-liquid separation: The reacted slurry is pumped into thickener 107, and after being flushed with the upper layer of clear water from multi-stage sedimentation tank 201, it is pumped into filter press 108 to achieve solid-liquid separation.

[0042] Wastewater treatment and recycling: 25% of the acidic washing liquid is pumped into multi-stage sedimentation tank 201 and neutralized to pH 9.0 with lime slurry. The supernatant is reused for washing, and 75% of the acidic washing liquid is returned to the slurry preparation.

[0043] The leaching results showed that the cyanide gold leaching rate of the pretreated concentrate reached 95.1%, and the arsenic removal rate was 90.5%.

[0044] Example 2 This embodiment processes a medium-low grade arsenic-containing gold ore with a gold grade of 4.5 g / t, an arsenic content of 2.8%, and a sulfur content of 15.5%.

[0045] The processing steps are as follows: Slurry preparation: The ore sample was ground to a fineness of -74 μm, accounting for 86%. The pH of the slurry was adjusted to 1.8 using 70% circulating acidic washing solution and 30% fresh water, and the solid content of the slurry was controlled at 18%.

[0046] Reaction: The pressure in reaction vessel 102 was set to 0.13 MPa. The ultrasonic power density was 60 W / L. Ozone at a concentration of 85 g / Nm³ was introduced. The reaction temperature was maintained at 25°C. The reaction time was controlled for 3.5 hours.

[0047] Exhaust gas treatment: The catalytic temperature of the decomposition tower 302 is set to 85℃.

[0048] Washing and solid-liquid separation: The oxidized slurry is subjected to countercurrent washing and pressure filtration.

[0049] Wastewater treatment and recycling: 20% of the acidic washing liquid is neutralized and precipitated, with the final pH controlled at 8.2. 80% of the acidic washing liquid is returned to the slurry preparation.

[0050] The leaching results showed that the cyanide gold leaching rate of the pretreated concentrate reached 78.3%, and the arsenic removal rate was 80.7%.

[0051] Example 3 This embodiment describes the processing of a highly difficult-to-process carbon-containing, high-arsenic gold concentrate with a gold grade of 41.8 g / t, an arsenic content of 11.2%, and a carbon content of 1.8%.

[0052] Slurry preparation: The ore sample was ultra-finely ground to -74 μm, with 95% of the sample being 0.75 μm. The pH of the slurry was adjusted to 1.5 using 70% circulating acidic washing solution and 30% fresh water, resulting in a solids content of 38%.

[0053] Reaction: The reaction pressure was 0.30 MPa, the ultrasonic power density was 280 W / L, the ozone concentration was 150 g / Nm³, and the reaction temperature was controlled at 45℃. The reaction time was 4 hours.

[0054] Exhaust gas treatment: The catalytic temperature of the decomposition tower is set to 115℃.

[0055] Washing and solid-liquid separation: The oxidized slurry is subjected to countercurrent washing and pressure filtration.

[0056] Wastewater treatment and recycling: 30% of the acidic washing liquid is neutralized and precipitated to pH 9.8 to ensure complete sedimentation of impurities. 70% of the acidic washing liquid is returned to the slurry preparation to balance the accumulation of impurities in the system.

[0057] The leaching results showed that the cyanide gold leaching rate of the pretreated concentrate reached 93.6%, and the arsenic removal rate was 94.8%.

[0058] Through the above three embodiments, by adapting the parameter combinations when processing different types of refractory gold ores, this process can stably and efficiently pre-treat the ore, thereby enhancing the subsequent flotation effect.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pretreatment device for arsenic-containing high-sulfur gold ore, characterized in that, include, Pretreatment unit (100) for oxidizing slurry; A water treatment facility (200) for purifying and circulating water; A gas processing unit (300) is used for catalytic oxidation of ozone; The pretreatment unit (100) includes an ozone generator (101), which is connected to a reaction vessel (102) via a pipe. Multiple ultrasonic transducers (103) are arrayed on the outer wall of the reaction vessel (102), and an air pump (104) is connected to the top of the reaction vessel (102) via a pipe.

2. The pretreatment device for arsenic-containing high-sulfur gold ore according to claim 1, characterized in that, The reaction vessel (102) is a sealed vessel. A feed inlet (105) is fixedly installed on the reaction vessel (102). A water inlet (106) is also fixedly installed on the reaction vessel (102). A thickener (107) is connected to the reaction vessel (102) through a pipe. A filter press (108) is connected to the thickener (107) through a pipe.

3. The pretreatment device for arsenic-containing high-sulfur gold ore according to claim 2, characterized in that, The water treatment unit (200) includes a multi-stage sedimentation tank (201), which is connected to a filter press (108) via a pipeline. A return pipe (202) is fixedly connected to the filter press (108), and the return pipe (202) is connected to the inlet (106) via a pipeline.

4. The pretreatment device for arsenic-containing high-sulfur gold ore according to claim 1, characterized in that, The gas processing unit (300) includes a gas-liquid separator (301), which is connected to a gas pump (104) via a pipeline, and the gas-liquid separator (301) is connected to a decomposition tower (302) via a pipeline.

5. A pretreatment process for arsenic-containing high-sulfur gold ore, used in the pretreatment apparatus for arsenic-containing high-sulfur gold ore as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Slurry preparation. After crushing and grinding the ore, it is mixed with circulating water and acid. The pH of the slurry after mixing is between 1.5 and 2.5, forming a homogeneous slurry. Step 2, reaction: The uniform slurry is added to the reaction tank (102). Ozone is introduced into the reaction tank (102) under positive pressure and ultrasound is applied at the same time. The slurry stays for 2-4 hours. Under the synergistic effect of ultrasonic cavitation, the ozone is efficiently converted into hydroxyl radicals, realizing the deep and rapid oxidation of sulfide minerals. Step 3: Tail gas treatment. After step 2 is completed, ozone is stopped from entering and the reaction tank (102) gradually enters a negative pressure state. The tail gas enters the gas-liquid separator (301). All the separated gas is sent to the decomposition tower (302) to completely decompose the residual ozone into oxygen before being safely discharged. Step 4: Washing and solid-liquid separation, depressurization, and oxidation of the slurry. The slurry enters the thickener (107), and the slag is washed with recycled water to recover solubles and reduce acidity. The washed slurry is then filtered by a filter press (108) to obtain pretreated concentrate and acidic washing liquid. Step 5: Wastewater treatment and recycling. 20%-30% of the acidic washing liquid enters the multi-stage sedimentation tank (201) for neutralization and sedimentation, and 70%-80% of the acidic washing liquid is directly returned to Step 1 as acid for recycling. The supernatant after sedimentation in the multi-stage sedimentation tank (201) is returned to the washing process in Step 4 as process water.

6. The pretreatment method for arsenic-containing high-sulfur gold ore according to claim 5, characterized in that, In step one, the proportion of mineral particles smaller than 74 μm in the mineral sample exceeds 85%, the acid is sulfuric acid solution, and the solid content of the slurry is 15-40%.

7. The pretreatment method for arsenic-containing high-sulfur gold ore according to claim 5, characterized in that, In step two, the positive pressure is 0.12-0.30 MPa, the ultrasonic power density is 50-300 W / L, the temperature is controlled at 20-50℃, and ozone is introduced at a constant concentration of 80-150 g / Nm³.

8. The pretreatment method for arsenic-containing high-sulfur gold ore according to claim 5, characterized in that, In step five, neutralization and precipitation are carried out using lime slurry or alkaline solution. The maximum pH in the multi-stage sedimentation tank (201) is 8-10, at normal temperature and pressure.

9. A pretreatment method for arsenic-containing high-sulfur gold ore according to claim 5, characterized in that, In step three, the decomposition tower (302) contains a catalyst, MnO2-CuO or Al2O3, and the catalytic temperature is 80-120℃.

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