A method for extracting and enriching noble metals from a fine particulate-containing noble metal ore

Abstract

The application discloses a method for extracting and enriching noble metals from noble metal-containing ores, which comprises the following steps: grinding some noble metal-containing ores with superfine particles by a common ball mill, adding chemicals and roasting, grinding again by a superfine grinding machine, oxidizing leaching, vacuum filtering, noble liquid reduction, roasting of the reduction product, fine grinding and the like, so that all noble metal elements can be extracted and enriched at one time. The whole production process is scientific and reasonable, and adopts a closed loop type of feeding, vacuum dust removal, tail gas recovery treatment and recycling of treated waste water. No waste gas is discharged, no waste water is discharged, and the method meets the environmental protection requirements. The method solves the problem of extracting noble metals from noble metal-containing ores with superfine particles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smelting, and more particularly to a method for extracting and enriching precious metals from a precious metal ore containing ultrafine particles. BACKGROUND

[0002] In recent years, with the increasing demand for precious metals in various industries, the international price of precious metals has fluctuated, mainly reflected in the increasing use of precious metals in the production of high-end industrial and technological products, handicrafts and jewelry, automobile environmental catalysts, and catalysts for petroleum, chemical industry, and pharmaceutical industry, leading to the shortage of precious metal resources. At present, the raw materials used by most domestic precious metal processing enterprises are mainly "binary" and "ternary" waste catalysts, and there is no ability to directly extract and enrich precious metals from raw ores. At the same time, the service life of various catalysts is strictly required. Therefore, the actual operation rate of most domestic processing enterprises is only about 60%. At the same time, due to the lack of understanding of the precious metal ore containing ultrafine particles by relevant institutions and enterprises in China, and the existence of industry barriers in some enterprises, the research and development investment for directly extracting and enriching precious metals from ores is far from enough. Therefore, the limited precious metal resources are not effectively utilized.

[0003] Due to these precious metal ores containing ultrafine particles, most of them belong to high-arsenic, high-sulfur, high-carbon, and high-silicon ores without cleavage, and their geological formation basically belongs to high-temperature hydrothermal ore body structure. Under high temperature conditions, part of the alloy has been formed, and it is difficult to leach (all precious metal elements) by ordinary single method.

[0004] Therefore, the present application provides a method for extracting and enriching precious metals, which can make the original high-density structure appear different high-oxidation layer states under the roasting action of the reagent, and then perform ultrafine grinding and use the linkage of comprehensive oxidizing agent to achieve rapid leaching and thorough leaching. SUMMARY

[0005] Therefore, the present application provides a method for extracting and enriching precious metals from a precious metal ore containing ultrafine particles, which is suitable for various ores, has high extraction and enrichment ratio, scientific process flow, and friendly production environment.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] A method for extracting and enriching precious metals from a precious metal ore containing ultrafine particles, comprising the following steps:

[0008] (1) the raw ore is broken and ball milled into ore powder, which is put into a stirrer, and concentrated flow acid, hydrogen peroxide, copper sulfate, sodium bisulfate, potassium bisulfate are added at the same time, after stirring evenly, aging for a period of time;

[0009] The raw ore refers to an ore (including tailings) containing superfine particles of precious metals, mainly including silica-containing ore, iron-copper ore, copper sulfide, iron ore, lead-zinc ore, manganese iron ore and other ore varieties;

[0010] (2) the aged ore is sent to a roasting kiln (which can be a rotary kiln, a shuttle roasting kiln or a tunnel kiln) for oxidation roasting to further oxidize the ore powder, achieve solidification and destroy the structure of the raw ore powder, and at the same time, a closed-loop gas extraction system is opened to perform multi-stage harmless treatment on the waste gas;

[0011] (3) the roasted ore is sent to a superfine grinding machine for superfine grinding, and the ground superfine powder is pumped into a powder storage tank for storage;

[0012] (4) the powder is pumped into an oxidation stirring barrel for oxidation leaching by a powder pumping machine, and at the same time, a closed-loop gas extraction system is opened to perform multi-stage harmless treatment on the waste gas;

[0013] (5) the ore slurry after oxidation leaching is first pumped into a sedimentation barrel for sedimentation treatment, and the supernatant is extracted for later use, then pure water is injected into the lower layer of the sedimentation, and a flocculating agent is added, stirred evenly, and then vacuum dewatering treatment is performed, the slag is sent for centralized treatment, and the liquid separated out is combined with the supernatant to obtain a liquid containing precious metal ions;

[0014] (6) the liquid containing precious metal ions is first heated and concentrated, then subjected to displacement reduction reaction, and then vacuum dewatering treatment is performed to obtain a reduced filter material;

[0015] (7) sodium carbonate is added to the reduced filter material, which is sent to a shuttle roasting kiln for reduction roasting, and the refined powder obtained after reduction roasting is finely ground to obtain a high-grade precious metal mixed concentrate powder with a total grade of 2000g / t-15000g / t.

[0016] Preferably, in step (1), the broken ball milling is broken to 100-200 mesh; 5%-20% of the concentrated flow acid, 5%-20% of the hydrogen peroxide, 0.5%-3% of the copper sulfate, 1%-5% of the sodium bisulfate and 1%-5% of the potassium bisulfate are added according to the mass of the ore powder; the aging is carried out in a 316L stainless steel tank for 1-2h.

[0017] The beneficial effects brought by the above-mentioned preferences are that the concentrated flow acid and hydrogen peroxide added will react to generate peroxymonosulfuric acid, which can greatly improve the oxidizability. The added potassium bisulfate and sodium bisulfate (which can be used alone or in combination) can chemically react with the peroxymonosulfuric acid under the condition of high-temperature roasting in the next step to generate stronger oxidizability, which can oxidize the precious metals and base metals in the ore into high-valence oxides, change the original properties and structure of the ore, and thus form a loose state, facilitating the next step of superfine grinding and oxidative leaching.

[0018] Preferably, the temperature of the oxidative roasting in step (2) is 400-900°C, and the time is 4-8h.

[0019] The beneficial effects brought by the above-mentioned preferences are that the selected rotary kiln can enable the matured ore to be directly fed from the kiln tail of the rotary kiln without drying and preheated (dried) for a certain period of time to enter the roasting zone for roasting. The main purposes are:

[0020] First, part of the sulfides in the ore are oxidatively roasted into oxides or sulfates, which facilitates the next step of superfine grinding and oxidative leaching.

[0021] Second, part of the oxides (belonging to sulfides) in the raw ore are sulfated and oxidatively roasted to become sulfates or solidified (i.e., ceramified, to prevent "gold robbing").

[0022] Third, the use of the rotary kiln for oxidative roasting has the advantages of large processing capacity, convenience, and easy management.

[0023] Preferably, the superfine grinding in step (3) is ground to 300-600 mesh.

[0024] The beneficial effects brought by the above-mentioned preferences are that the ore after oxidative roasting will have different sizes and hardnesses due to the different elements inside. Therefore, after superfine grinding, the fineness reaches 500 mesh, which can play a role in destroying the original structure of the ore, achieving the purpose of improving the oxidative leaching rate, and shortening the leaching time.

[0025] Preferably, in step (4), the mass ratio of the oxidative leaching solution to the powder in the oxidative leaching is (3-5):1, and the mass concentration of the oxidative leaching solution is 20%-40%.

[0026] The beneficial effects brought by the above-mentioned preferences are that the mass ratio of the oxidative leaching solution to the ore powder in the oxidative leaching process is (3-5):1, and the liquid-solid ratio selected in this method is 4:1, i.e., 4 tons of leaching solution are used for one ton of ore powder. The concentration of the oxidative leaching solution is 20%-40%, and the concentration of the oxidative leaching solution selected in this method is 30%. This can maximize the leaching rate while considering the production cost.

[0027] Preferably, the oxidizing leaching solution comprises: an oxidizing agent, a catalyst, a leaching aid, and an acid;

[0028] The oxidizing agent is sodium chlorate and sodium hypochlorite, the amount of sodium chlorate is 10%-30% of the mass of the ore powder, and the amount of sodium hypochlorite is 5%-20% of the mass of the ore powder;

[0029] The catalyst is hydrogen peroxide, and the amount of hydrogen peroxide is 5%-20% of the mass of the ore powder;

[0030] The leaching aid is sodium chloride, and the amount of sodium chloride is 10%-20% of the mass of the ore powder;

[0031] The acid is hydrochloric acid and / or nitric acid, the amount of hydrochloric acid is 50%-90% of the mass of the ore powder, and the amount of nitric acid is 30%-60% of the mass of the ore powder;

[0032] The temperature of the oxidizing leaching is 60°C-95°C, air is continuously supplied to the stirring barrel, and continuous stirring is performed for 2-4 hours.

[0033] The above-mentioned preferred method has the following beneficial effects:

[0034] The purposes of using the oxidizing agent, the catalyst, and the leaching aid.

[0035] First, sodium chlorate and sodium hypochlorite in the oxidizing agent can generate chlorine dioxide under the catalytic action of hydrogen peroxide in an acidic solution, chlorine dioxide can release atomic oxygen and chlorine gas, and the oxidizing property of chlorine dioxide is 3-5 times that of ordinary oxidizing agents, and the leaching rate of noble metals can reach more than 98%.

[0036] Second, the catalyst (hydrogen peroxide) can accelerate the speed of oxidizing leaching.

[0037] Third, the use of the leaching aid (sodium chloride) can improve the generation of chlorine gas under acidic and oxidizing conditions, which is conducive to oxidizing leaching.

[0038] Fourth, the use amount of various reagents is the most scientific and reasonable amount based on years of experimental experience and considering the production cost.

[0039] Fifth, the temperature of the oxidizing leaching is 60°C-95°C, and the leaching temperature used in the method is 90°C, which can better enable various reagents to play an effective role and improve the oxidizing leaching rate and speed.

[0040] Sixth, continuous air supply to the stirring barrel can increase the concentration of oxygen in the oxidizing leaching process, thereby achieving the purpose of more complete oxidation.

[0041] Seven is continuous stirring 2-4 hours, is to make the oxidizing agent in the oxidation leaching process, can fully react with noble metal, to improve the leaching rate.

[0042] Preferably, the precipitation time in step (5) is 4-6h; the amount of pure water added is 0.5-2t; the amount of flocculant added is 30mg solid flocculant per liter of ore pulp; the method of using the solid flocculant is to configure the solid flocculant into a flocculant solution with a mass concentration of 0.01%-0.05% before use; the stirring time is 10-30min.

[0043] The above preferred beneficial effects are: because the ore powder after superfine grinding has a fineness of 500 mesh, if directly filtered and dewatered with a dewatering device, ore loss will occur and the dewatering effect will be compromised. Therefore, it is necessary to first precipitate, extract the supernatant (noble liquid), then add the same mass of pure water as the ore, stir for 30 minutes, and then add the flocculant liquid.

[0044] Preferably, step (6) specifically comprises: placing the liquid containing noble metal ions into a reduction barrel, then adding a sodium hydroxide solution with a concentration of 10-30%, adjusting the pH to 2-5, stirring, and heating to 60-80℃, then adding charcoal powder with a mass of 5-20% of the ore powder to the reduction barrel, and adding hydrazine hydrate with a mass of 5-15% of the ore powder, sodium borohydride with a mass of 1-3%, reducing and stirring for 3-6h, and then pumping to a vacuum dewatering machine for dewatering. The dewatered water is pumped to a centralized place for reuse, and the reduced filter material is ready for use.

[0045] The above preferred beneficial effects are: placing the filtered liquid containing noble metals (i.e. noble liquid) into a reduction stirring barrel, then adding a 20% sodium hydroxide solution, which serves to:

[0046] (1) Adjust the pH of the noble liquid to about 3, which is conducive to the effective use of the reducing agent.

[0047] (2) Heating to 60-80℃ can further activate the noble metal ions in the noble liquid.

[0048] (3) Adding charcoal powder with a mass of 10% of the ore powder to the reduction barrel is to absorb the residual oxidizing agent in the noble liquid, and also to adsorb part of the noble metal ions, and to prevent sticking to the dewatering machine membrane cloth in the subsequent dewatering process.

[0049] (4) Adding hydrazine hydrate with a mass of 10% of the ore powder to the reduction barrel.

[0050] 1% of sodium borohydride, and stirring for 3 hours. In order to completely reduce the noble metal ions in the noble liquid, the reduction product (noble metal concentrate) is obtained after dehydration by a vacuum dewatering machine, and the filtrate (PH = 7) is transparent clear water, which can be reused.

[0051] Preferably, the amount of sodium carbonate added in step (7) is 5%-20% of the mass of the reduction filtrate; the temperature of the calcination is 300-600°C, and the time is 4-6h; and the fine grinding is to 200 mesh.

[0052] The above-mentioned preferred beneficial effects are: the amount of sodium carbonate added is 5% of the mass of the reduction product, and the sodium carbonate is mixed with the reduction product first, and then placed in a shuttle calcination kiln for reduction calcination, the calcination temperature is about 500°C, and the calcination time is 4 hours. The purpose is that since part of the reduction product is only reduced to a low-valence ion state, there is still part of the chloride ion. Only by adding sodium carbonate for reduction calcination, can the sodium ion in the sodium carbonate and the chloride ion generate sodium chloride (soluble in water) in the reduction calcination atmosphere, and the carbonate radical is decomposed into carbon dioxide and discharged during the calcination process. At the same time, since the original added charcoal powder plays the role of a reducing agent in the reduction calcination, the reduction calcination is more perfect, so that the noble metal elements can reach the enrichment concentrate of the metal phase or the sponge metal phase. Finally, the reduction calcination product is finely ground to 200 mesh, which is convenient for standard sampling during detection, and is also beneficial to the next step of finishing. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art descriptions. Obviously, the drawings in the following description are only a part of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on the provided drawings.

[0054] Figure 1 The process flow chart of the present application. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0056] Embodiment 1

[0057] The method for extracting and enriching noble metals from a noble metal ore containing ultrafine particles will be further described below with reference to the drawings. The following steps are adopted:

[0058] 1. Put 200 grams of quartz ore powder (quartz content 99.2%, noble metal and other element content 0.8%, containing valuable noble metal worth 100,000 yuan) into a blender, and add 15% of concentrated hydrochloric acid, 15% of hydrogen peroxide, 1.5% of copper sulfate, 2% of sodium bisulfate, and 2% of potassium bisulfate by weight of the ore powder. After stirring evenly, transfer to a 316L stainless steel container for 1-2 hours of aging.

[0059] 2. Put the aged ore into a porcelain crucible and place it in a muffle furnace for 4 hours of roasting at a temperature of 800°C. This further oxidizes the ore, solidifies it, and destroys the structure of the original ore powder. At the same time, open the closed-loop gas extraction system to perform multi-stage harmless treatment of the exhaust gas.

[0060] 3. Grind the roasted ore into a fine powder again.

[0061] 4. Add the fine ore powder to an oxidation leaching tank and stir to perform oxidation leaching. The liquid-to-solid ratio of the oxidation leaching liquid to the ore powder is 4:1, and the concentration of the leaching liquid is 35% (referring to the concentration of the acid). The oxidizing agent in the leaching liquid is sodium chlorate and sodium hypochlorite, with the amount of sodium chlorate being 20% of the weight of the ore powder and the amount of sodium hypochlorite being 10% of the weight of the ore powder.

[0062] The catalyst is hydrogen peroxide, and its amount is 15% of the weight of the ore powder. The leaching aid is sodium chloride, and its amount is 15% of the weight of the ore powder.

[0063] The acid in the leaching liquid is hydrochloric acid and nitric acid, with the amount of hydrochloric acid being 75% of the weight of the ore powder and the amount of nitric acid being 25% of the weight of the ore powder. Air is supplied to the stirring tank, and the temperature is heated to 80°C. Start stirring and oxidation leaching for 4 hours.

[0064] 5. After vacuum dewatering, take the filtered liquid (noble liquid).

[0065] 6. Send the noble liquid to a reduction tank. When the pH value is adjusted to 3 with 20% sodium hydroxide, add 10% charcoal powder, 10% hydrazine hydrate, and 1.5% sodium borohydride by weight of the ore powder. Heat to 80°C and stir for 4 hours of reduction. After vacuum dewatering, obtain the reduced filtered material.

[0066] 7. Add 15% sodium carbonate (by weight of the reduced material) to the reduced filtered material and reduce it in a reduction roasting kiln at a roasting temperature of 500°C for 4 hours.

[0067] 8. Obtain the reduced roasting material, grind it to 200 mesh, and become a concentrate powder rich in high-grade noble metals.

[0068] 9. After detecting the tailings after the oxidation leaching, the grade of silicon dioxide reached 99.99% (containing 100 g / t of noble metals and other elements), indicating that 7900 g / t of material (noble metals, base metals and other elements) had been leached and extracted. It is proved that the leaching and extraction enrichment recovery rate reaches more than 98%.

[0069] 10. The content of noble metals in the quartz ore powder (the results detected by ICP of professional institutions).

[0070] Element ICP ore sample assay content g / t Ruthenium 200 Rhodium 0 Palladium 179 Silver 2923 Osmium 217 Platinum 0 Gold 54 Iridium 244

[0071] In Example 1, the detection of the tailings (silicon dioxide) generated thereby showed that the silicon dioxide content reached 99.99% (containing 100 g / t of noble metals and other elements). It is indicated that 7900 g / t of material (noble metals, base metals and other elements) has been leached and extracted. By detecting the content of the tailings, it is proved that the leaching and extraction enrichment recovery rate reaches 98%.

[0072] Example 2

[0073] 1. Take 100 grams of a certain gold ore sample from Yunnan and grind it into 200 mesh ore powder. Add chemicals for pretreatment, i.e. add 15% concentrated sulfuric acid, 15% hydrogen peroxide, 1.5% copper sulfate, 2% sodium bisulfate, and 2% potassium bisulfate by mass of the ore powder, stir uniformly, and then transfer into a 316L stainless steel container for 1.5 hours of curing.

[0074] 2. Put the cured ore material into a porcelain crucible and put it into a muffle furnace for roasting for 4 hours at a roasting temperature of 800°C. This further oxidizes the ore powder to achieve solidification, destroys the structure of the ore powder, and at the same time opens the closed-loop gas extraction system for multi-stage harmless treatment of waste gas.

[0075] 3. The roasted ore material is again ground into ultra-fine powder (all through 300 mesh).

[0076] 4. The ultra-fine ore powder is added to the oxidation leaching barrel for stirring and oxidation leaching. The liquid-solid ratio of the oxidation leaching liquid to the ore powder is 3:1, and the concentration of the leaching liquid is 30% (referring to the concentration of the acid). The oxidizing agent in the leaching liquid is sodium chlorate and sodium hypochlorite, the dosage of sodium chlorate is 20% of the mass of the ore powder, the dosage of sodium hypochlorite is 10% of the mass of the ore powder; the catalyst is hydrogen peroxide, the dosage is 15% of the mass of the ore powder; the leaching aid is sodium chloride, the dosage is 15% of the mass of the ore powder. The acid in the leaching liquid is hydrochloric acid and nitric acid, among which the dosage of hydrochloric acid is 75% of the mass of the ore powder, and the dosage of nitric acid is 25% of the mass of the ore powder. Air is sent to the stirring barrel and heated to 80°C, and stirring and oxidation leaching is started for 4 hours.

[0077] 5. After vacuum dewatering (filtration), the filtrate (called "noble liquid") is extracted.

[0078] 6. The noble liquid is pumped into the reduction barrel for reduction reaction. 20% sodium hydroxide is added into the barrel, the PH value is adjusted to 3, then 10% charcoal powder, 10% hydrazine hydrate, 1.5% sodium borohydride of the mass of the ore powder are added, heated to 80℃, and stirred for 4 hours. After vacuum dehydration (filtration), the reduction filtrate is obtained.

[0079] 7. 15% sodium carbonate of the mass of the reduction product is added into the reduction filtrate, and reduction roasting is carried out at 400℃ for 4 hours.

[0080] 8. The reduction roasting product is obtained, ground to 200 mesh, and becomes the concentrate powder of extraction and enrichment of noble metals with high grade.

[0081] 9. The spectral detection of the professional testing agency shows that the detection result of the concentrate powder (the enrichment ratio is 15 times) is as follows:

[0082] Element wt% by weight g / t Ruthenium 0.016 160 Rhodium 0.111 1110 Palladium 0.070 700 Silver 0.058 580 Osmium 0.060 600 Platinum 0.503 5030 Gold 0.078 780 Iridium 0.000 0

[0083] Example 3

[0084] 1. 100 grams of an iron-gold ore sample in Sichuan is taken, the process flow and the medication system of the application are used for experiment (the same as example (two)), and finally the concentrate powder of extraction and enrichment is obtained,

[0085] The spectral detection result of the professional testing agency is as follows:

[0086]

[0087]

[0088] From the above examples 1-3, it can be seen that the matching equipment used in the application is correct, the whole process flow and the medication system are scientific and reasonable. The advantages can be better played, and noble metals can be extracted and enriched with full range and high efficiency.

[0089] At present, there is no enterprise engaged in extraction and enrichment of noble metals from raw ore in China, only a few small enterprises with daily processing capacity of less than 20 tons are engaged in the extraction and enrichment of noble metals, and they do not have a complete set of production equipment as in the application, and can only extract and enrich one or several noble metal elements from the ore, and cannot extract noble metals in eight elements at one step.

[0090] In addition, from the domestic patent information related to the extraction and enrichment of noble metals, a considerable part of the patents is only for the purpose of applying for a patent, and there is little practical value, and some cannot be used for production, not to mention the use of large-scale process flow.

[0091] Therefore, the working principle and function of the equipment used in each link in the present application are demonstrated by scientific experiments, and it is proved that the functional advantages and process flow can be used for actual industrial production.

[0092] The various embodiments are described in the specification with progressive levels of detail. Each embodiment can be used to describe a different aspect of the present application. The same numbers are used in different embodiments and no particularized description of these numbers is needed since the numbers themselves will be understood by those of ordinary skill in the art. The various embodiments are not mutually exclusive, but can be combined with each other. The same or similar reference numerals in different figures represent the same or similar functions.

[0093] The above description of disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for extracting and enriching noble metals from a fine-particle-containing noble metal ore, characterized by, The method comprises the following steps: (1) crushing and ball milling the raw ore into ore powder, and putting the ore powder into a stirring machine while adding concentrated stream acid, hydrogen peroxide, copper sulfate, sodium bisulfate, and potassium bisulfate, stirring uniformly, and aging for a period of time; (2) oxidizing and roasting the aged ore, and starting a closed-loop air extraction system to perform multi-stage harmless treatment on the exhaust gas; (3) performing superfine grinding on the roasted ore, and storing the ground superfine powder for later use; (4) extracting the powder, and performing oxidation leaching while starting the closed-loop air extraction system to perform multi-stage harmless treatment on the exhaust gas; (5) extracting the supernatant after precipitation of the leached ore slurry, then adding pure water to the lower layer of the precipitate, adding a flocculating agent, stirring uniformly, and then performing vacuum dewatering treatment, and combining the extracted liquid with the supernatant to obtain a liquid containing noble metal ions; (6) performing heating and concentration on the liquid containing noble metal ions, then performing displacement reduction reaction, and then performing vacuum dewatering treatment to obtain a reduced filterate; (7) adding sodium carbonate to the reduced filterate, then performing reduction roasting, and then performing fine grinding on the obtained fine powder to obtain a high-grade noble metal mixed concentrate powder.

2. The method of claim 1, wherein the method is characterized by, In step (1), the crushing and ball milling is to 100-200 mesh; the concentrated stream acid, hydrogen peroxide, copper sulfate, sodium bisulfate, and potassium bisulfate are added in an amount of 5%-20% of the mass of the ore powder; the aging is performed in a 316L stainless steel tank for 1-2 hours.

3. The method of claim 1, wherein the method is characterized by, In step (2), the temperature of the oxidation roasting is 400-900°C, and the time is 4-8 hours.

4. The method of claim 1, wherein the method is characterized by, In step (3), the superfine grinding is to 300-600 mesh.

5. The method of claim 1, wherein the method is characterized by: In step (4), the mass ratio of the oxidation leaching liquid to the powder is (3-5):1; and the mass concentration of the oxidation leaching liquid is 20%-40%.

6. The method of extracting and enriching precious metals from a precious metal ore containing ultrafine particles according to claim 5, characterized in that, The oxidation leaching liquid is hydrochloric acid and / or nitric acid; the amount of the hydrochloric acid is 50%-90% of the mass of the ore powder; and the amount of the nitric acid is 30%-60% of the mass of the ore powder.

7. The method of extracting and enriching precious metals from a precious metal ore containing ultrafine particles according to claim 5, characterized in that, The oxidation leaching liquid further comprises an oxidizing agent, a catalyst, and a leaching aid; The oxidizing agent is sodium chlorate and sodium hypochlorite; the amount of the sodium chlorate is 10%-30% of the mass of the ore powder; and the amount of the sodium hypochlorite is 5%-20% of the mass of the ore powder; The catalyst is hydrogen peroxide; and the amount of the hydrogen peroxide is 5%-20% of the mass of the ore powder; The leaching aid is sodium chloride; and the amount of the sodium chloride is 10%-20% of the mass of the ore powder; The temperature of the oxidation leaching is 60-95°C; air is continuously supplied to the stirring barrel; and the stirring is continuously performed for 2-4 hours.

8. The method of extracting and enriching precious metals from a precious metal ore containing ultrafine particles according to claim 1, characterized in that, In step (5), the precipitation time is 4-6 hours; the amount of the pure water added is 0.5-2 t; the amount of the flocculating agent added is 30 mg of solid flocculating agent per liter of the ore slurry; the solid flocculating agent is configured into a flocculating agent solution with a mass concentration of 0.01%-0.05% before use; and the stirring time is 10-30 minutes.

9. The method of claim 1, wherein the method is characterized by, The step (6) specifically comprises: placing the liquid containing noble metal ions into a reduction bucket, then adding sodium hydroxide solution with mass concentration of 10-30%, adjusting pH to 2-5, stirring and heating to 60-80 DEG C, then adding charcoal powder with 5-20% of the mass of the ore powder in step (1) into the reduction bucket, and adding hydrazine hydrate with 5-15% of the mass of the ore powder, sodium borohydride with 1-3% of the mass of the ore powder, reducing and stirring for 3-6 hours, and then dehydrating in a vacuum dewatering machine, the dehydrated water is pumped to a centralized place for reuse, and the reduction filtrate is reserved.

10. The method of claim 1, wherein the method is characterized by, The adding amount of the sodium carbonate in step (7) is 5-20% of the mass of the reduction filtrate; the temperature of the calcination is 300-600 DEG C, and the time is 4-6 hours; the fine grinding is to 200 mesh.

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