A method for leaching sulfide minerals

Abstract

The present invention provides a leaching method for sulfide minerals, which comprises: grinding the sulfide minerals for a second time, adding concentrated sulfuric acid during the second grinding for pre-activation, and obtaining a second-grinded material; adding the second-grinded material into a sulfuric acid solution for normal pressure leaching to obtain a normal pressure leaching slurry; wherein, at least one of stirring, introducing oxygen, and maintaining the normal pressure leaching temperature is performed during the normal pressure leaching process; filtering the normal pressure leaching slurry to obtain normal pressure leaching slag and normal pressure leaching liquid; slurrying the normal pressure leaching slag with sulfuric acid solution, and then performing pressure leaching, and performing at least one of introducing oxygen, adjusting the air pressure, and adjusting the initial temperature of the pressure leaching during the pressure leaching process, filtering after the reaction is complete, and obtaining a pressure leaching liquid and a pressure leaching slag. The method can improve the leaching rate of the target metal in the normal pressure leaching stage, reduce the processing amount of sulfide minerals in the pressure leaching stage, and reduce energy consumption, cost, and safety hazards.

Description

Technical Field

[0001] The invention relates to the field of nonferrous metal hydrometallurgy, and in particular to a leaching method for sulfide minerals. Background Art

[0002] As one of the two major technologies of extractive metallurgy, hydrometallurgy is a process that brings ores or other raw materials into contact with aqueous solutions or other liquids, and performs leaching and solid-liquid separation through chemical reactions to extract target metals or their compounds. In the hydrometallurgical industry, the target metals extracted from copper and cobalt raw materials represented by copper-cobalt sulfide ores and copper-cobalt alloys, and nickel raw materials represented by nickel sulfide ores, high-grade nickel matte, and low-grade nickel matte account for a considerable proportion. Therefore, it is very necessary to study the leaching process in the hydrometallurgical process of sulfide minerals for the development of modern metallurgy.

[0003] Taking the extraction of nickel from high-grade nickel matte as an example, the conventional extraction process is to grind the high-grade nickel matte to 200 meshes with a ball mill, then perform atmospheric leaching in a dilute sulfuric acid solution at normal pressure, perform acid leaching on a large amount of nickel element in the atmospheric leaching stage, and then pump the slurry after atmospheric leaching into an oxygen pressure leaching kettle, and continue to leach the unleached nickel under high pressure, high temperature and oxygen-rich conditions. While extracting nickel, more than 90% of the impurity copper in the high-grade nickel matte is also leached, and about 20% of the iron is leached. Then, soda ash is added to the solution containing impurities such as nickel, iron and copper after the reaction to neutralize and hydrolyze the iron and copper to achieve the purpose of purification. The purified solution is then extracted to deeply purify other impurities, and finally a high-purity nickel sulfate solution is produced, which can be directly used to produce high-purity nickel products.

[0004] The process of hydrometallurgical extraction of target metals from other sulfide minerals is similar to the process of extracting nickel from high-grade nickel matte.

[0005] However, in the above process, the step of grinding the high nickel matte to 200 mesh using a ball mill only reduces the size of the sulfide minerals for subsequent normal pressure leaching and pressurized leaching, resulting in a low leaching rate of the target metal in the normal pressure leaching stage. More than 70% of the leaching reactions need to be carried out under pressurized oxygen-enriched conditions. In the high-pressure oxygen-enriched leaching stage, multiple stages of pressurized leaching are required to ensure a high leaching rate of the target metal. Therefore, a large number of high-pressure oxygen-enriched reaction equipment need to be configured in the process of extracting the target metal. The equipment investment is large and the required electricity is huge. At the same time, the configuration of a large number of high-pressure oxygen-enriched equipment greatly increases the safety risks of the production process.

[0006] Therefore, how to improve the grinding process to increase the leaching rate of the target metal in the atmospheric pressure leaching stage, thereby reducing the processing volume of sulfide minerals in the pressurized oxygen-enriched leaching stage, simplifying the extraction equipment, reducing energy consumption and costs, and reducing safety hazards in the production process has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] In view of the technical problem that in the prior art, the leaching rate of the target metal in the atmospheric pressure leaching stage is low, resulting in the need to use multiple stages of pressurized leaching in the high-pressure oxygen-enriched leaching stage to ensure a high leaching rate of the target metal.

[0008] The present invention provides a leaching method for sulfide minerals, which comprises:

[0009] S1, grinding the sulfide mineral for a second time, and adding concentrated sulfuric acid during the second grinding for pre-activation to obtain a second-grinded material;

[0010] S2, adding the secondary ground material into a sulfuric acid solution, performing normal pressure leaching, and obtaining a normal pressure leaching slurry; wherein at least one of stirring, introducing oxygen, and maintaining the normal pressure leaching temperature is performed during the normal pressure leaching process;

[0011] S3, filtering the atmospheric pressure leaching slurry to obtain atmospheric pressure leaching residue and atmospheric pressure leaching liquid;

[0012] S4, adding the atmospheric leaching residue into the sulfuric acid solution for slurrying, and then performing pressure leaching, and performing at least one of the operations of introducing oxygen, adjusting the air pressure, and adjusting the initial temperature of the pressure leaching during the pressure leaching process, filtering after sufficient reaction to obtain pressure leaching residue and pressure leaching solution.

[0013] Preferably, after S4, the leaching method further comprises:

[0014] S5, performing impurity removal treatment on the pressurized leaching solution, and filtering to obtain the impurity-removed leaching solution.

[0015] Preferably, in S1, the secondary grinding is first the first stage grinding and then the second stage grinding; concentrated sulfuric acid is added in the second stage grinding for pre-activation; the particle size of the material after the secondary grinding must meet the following requirements: the particle size D90 of the material after the first stage grinding is less than 80 microns, and the particle size D90 of the material after the secondary grinding is less than 40 microns; the concentration of sulfuric acid in the concentrated sulfuric acid in S1 is 1400-1800 g / L, and the amount of concentrated sulfuric acid added is 1.0-5.5% of the weight of the sulfide mineral; the addition rate of concentrated sulfuric acid is 0.1-0.5 t / h; concentrated sulfuric acid is added by pipeline transport and spraying; preferably, the first stage grinding adopts a ball mill or a Raymond mill for coarse grinding, and the second stage grinding adopts a tube mill, a vibration mill or a mechanical stirring mill for fine grinding.

[0016] Preferably, in S2, the sulfuric acid concentration in the sulfuric acid solution is 100g / L-160g / L; in S4, the sulfuric acid concentration in the sulfuric acid solution is 10g / L-100g / L. The amount of material is determined according to the mass of the sulfide mineral therein, and the mass of the sulfide mineral is determined according to the mass of sulfuric acid; wherein, the mass of the sulfide mineral = (mass of total sulfuric acid × molar mass of metal element to be leached / molar mass of sulfuric acid) × 1.05 / [1-(mass percentage of sulfur in sulfide ore × molar mass of metal element to be leached / molar mass of sulfur element) / percentage of metal element to be leached in sulfide ore].

[0017] Preferably, in S2, the device for atmospheric pressure leaching reaction is an atmospheric pressure leaching device; the oxygen introduction rate is 10-60Nm 3 / h, and the purity of oxygen is >90%;

[0018] The device for introducing oxygen is an ultrasonic super-energy oxidizer, which is connected to an oxygen gas source and communicated with the bottom of the atmospheric pressure leaching device;

[0019] The oxygen is introduced in the following manner: the ultrasonic super-energy oxidizer mixes the slurry of the secondary ground material and sulfuric acid solution flowing out of the upper part of the atmospheric pressure leaching device with the introduced oxygen, and then injects it into the atmospheric pressure leaching device from the bottom of the atmospheric pressure leaching device.

[0020] Preferably, the stirring rate is 50-120 r / min;

[0021] Preferably, the atmospheric pressure leaching temperature is maintained at 60-90°C;

[0022] Preferably, the leaching time at normal pressure is 2-13 hours.

[0023] Preferably, in S4, the slurrying time is 0.5-2h; oxygen is used for pressurization and the pressure is maintained at 1.4-1.8Mpa, and the purity of oxygen is greater than 90%; and the initial temperature of the pressurized leaching is adjusted to 120-140°C.

[0024] Preferably, the pressure leaching time is 2-5 hours.

[0025] Preferably, the sulfide mineral is at least one or more of nickel sulfide ore, copper-cobalt sulfide ore, cobalt-copper alloy, high nickel matte, and low nickel matte.

[0026] Preferably, when the sulfide mineral is at least one or more of nickel sulfide ore, high nickel matte, and low nickel matte, S5 specifically comprises: adjusting the pH and temperature of the pressurized leaching solution, adding a LIX extractant, using a four-stage centrifugal extraction method to remove copper and purify, and then filtering to obtain a decontaminated leaching solution.

[0027] Preferably, in S5, the pH of the pressurized leaching solution is maintained at 1-2; the temperature of the pressurized leaching solution is maintained at ≤55°C; and the organic ratio of the four-stage centrifugal extraction method is LIX extractant: solvent oil = (20% to 30%): (70% to 80%).

[0028] In summary, the present invention provides a leaching method for sulfide minerals. In the grinding stage, concentrated sulfuric acid is used to pre-activate the sulfide minerals, which accelerates the oxidation reaction of sulfides in the sulfide minerals and the leaching reaction of elemental metals in the sulfide minerals; further, an ultrasonic super-energy oxidizer is used to fully disperse oxygen, and the particle size of the ground sulfide minerals must meet the requirement of D90<40 microns, which greatly increases the specific surface area of ​​the material and the contact area with oxygen, and further increases the reaction rate of sulfide oxidation at normal pressure and the leaching rate of the target metal. Thereby, the processing amount of sulfide minerals in the pressurized leaching stage can be reduced, and the purpose of simplifying the extraction equipment for pressurized leaching, reducing energy consumption and costs, and reducing safety hazards in the production process can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 : A flow chart of a sulfide mineral leaching method provided in an embodiment of the present invention;

[0031] Figure 2 : A flow chart of a sulfide mineral leaching method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above and other features and advantages of the present invention more clear, the present invention is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0033] In the following description, many specific details are set forth to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that specific details need not be adopted to practice the present invention. In other cases, well-known steps or operations are not described in detail to avoid obscuring the present invention.

[0034] In order to improve the leaching rate of the target metal in the atmospheric pressure leaching stage, thereby reducing the processing volume of sulfide minerals in the pressurized oxygen-enriched leaching stage, simplifying the extraction equipment, reducing energy consumption and costs, and reducing safety hazards in the production process. Figure 1 As shown, the present invention provides a sulfide mineral leaching method, the leaching method comprising:

[0035] S1, grinding the sulfide mineral for a second time, and adding concentrated sulfuric acid during the second grinding for pre-activation to obtain a second-grinded material;

[0036] In the present application, the sulfide mineral is at least one or more of nickel sulfide ore, copper-cobalt sulfide ore, cobalt-copper alloy, high nickel matte, and low nickel matte.

[0037] The secondary grinding is first grinding and then second grinding; concentrated sulfuric acid is added in the second grinding for pre-activation;

[0038] More specifically, the first stage of the secondary grinding is coarse grinding with a ball mill, and the second stage of the grinding is fine grinding with a sand mill; in a further preferred embodiment, the first stage of the grinding is coarse grinding with a ball mill or a Raymond mill, and the second stage of the grinding is fine grinding with a tube mill, a vibration mill or a mechanical stirring mill.

[0039] The particle size of the sulfide mineral after the first grinding stage must meet the abrasive requirement of particle size D90 < 80 microns, and the particle size of the sulfide mineral after the second grinding stage must meet the abrasive requirement of particle size D90 < 40 microns, so as to ensure that the material can fully contact with oxygen during the subsequent leaching process.

[0040] Furthermore, concentrated sulfuric acid is added in the second stage of grinding, the concentration of sulfuric acid in the concentrated sulfuric acid is 1400-1800g / L, and the amount of concentrated sulfuric acid added is 1.0-5.5% of the weight of the sulfide mineral; the addition rate of concentrated sulfuric acid is 0.1-0.5t / h; concentrated sulfuric acid is added by pipeline transportation and spraying; pre-activation is performed by using the oxidizing property of concentrated sulfuric acid and the mechanical strength and friction heat in the grinding process. On the one hand, the oxidation reaction of sulfide in sulfide mineral can be accelerated, and on the other hand, the leaching reaction of elemental metal in sulfide ore can be accelerated.

[0041] S2, adding the secondary ground material into a sulfuric acid solution, performing normal pressure leaching, and obtaining a normal pressure leaching slurry; wherein, during the normal pressure leaching process, at least one of stirring, introducing oxygen, and maintaining the normal pressure leaching temperature is performed.

[0042] In this step, the concentration of the sulfuric acid solution is 100g / L-160g / L, so as to utilize the strong oxidizing property of the relatively high concentration of sulfuric acid to oxidize part of the metal sulfides. The mass of the sulfide mineral is determined according to the mass of the sulfuric acid. Specifically, the mass of the sulfide mineral = (the mass of the total sulfuric acid × the molar mass of the metal element to be leached / the molar mass of the sulfuric acid) × 1.05 / [1-(the mass percentage of sulfur in the sulfide ore × the molar mass of the metal element to be leached / the molar mass of the sulfur element) / the percentage of the metal element to be leached in the sulfide ore].

[0043] The device for atmospheric pressure leaching reaction is an atmospheric pressure leaching device; the oxygen introduction rate is 10-60Nm 3 / h, and the purity of oxygen is greater than 90%; specifically, an ultrasonic super-energy oxidizer connected to the upper part of the atmospheric pressure leaching device is used to mix the slurry obtained by mixing the sulfide mineral and the sulfuric acid solution with the introduced oxygen, and then the slurry is pumped into the atmospheric pressure leaching device from the bottom of the atmospheric pressure leaching device. The dispersion effect of oxygen is greatly increased by ultrasonic waves, and at the same time, the material is ground to a particle size of 40 microns in the second stage of grinding, which greatly increases the specific surface area of ​​the material and the contact area with oxygen, thereby greatly increasing the reaction rate of atmospheric pressure oxidation of sulfides and the leaching rate of the target metal.

[0044] The stirring rate is 50-120r / min to further disperse the oxygen introduced into the atmospheric pressure leaching device, and the atmospheric pressure leaching temperature is maintained at 60-90°C to ensure the appropriate temperature for the atmospheric pressure leaching reaction; the atmospheric pressure leaching time is 2-13h to ensure sufficient atmospheric pressure leaching reaction.

[0045] S3, filtering the atmospheric pressure leaching slurry to obtain atmospheric pressure leaching residue and atmospheric pressure leaching liquid.

[0046] In the present application, after atmospheric pressure leaching, the atmospheric pressure leaching slurry is filtered to obtain atmospheric pressure leaching residue and atmospheric pressure leaching liquid. The atmospheric pressure leaching liquid is a sulfate solution of the target metal, which can be directly used to produce high-purity target metal series products, and the atmospheric pressure leaching residue contains sulfides of the target metal, which can be used for subsequent extraction operations.

[0047] S4, adding the atmospheric leaching residue into the sulfuric acid solution for slurrying, and then performing pressure leaching, and performing at least one of the operations of introducing oxygen, adjusting the air pressure, and adjusting the initial temperature of the pressure leaching during the pressure leaching process, filtering after sufficient reaction to obtain pressure leaching residue and pressure leaching solution.

[0048] In the present application, the atmospheric leaching residue is added to the sulfuric acid solution for 0.5-2h, wherein the sulfuric acid concentration in the sulfuric acid solution is 10g / L-100g / L, and then transported to the pressure leaching device, and the gas pressure in the pressure leaching device is pressurized and maintained at 1.4-1.8Mpa by oxygen, and the temperature in the pressure leaching device is raised to 120-140°C, and the pressure oxidation reaction begins to react violently, and the reaction temperature is maintained by the heat release of the reaction itself until the pressure oxidation reaction ends. Among them, the pressure leaching time is 2-5h, and the reaction temperature can reach above 160°C by the heat release of the reaction itself.

[0049] like Figure 2 As shown, in some preferred embodiments, the leaching method further comprises:

[0050] S5, when the sulfide mineral is at least one or more of nickel sulfide ore, high nickel matte, and low nickel matte,

[0051] S5 specifically comprises: adjusting the pH and temperature of the pressurized leaching solution, adding LIX extractant, performing copper removal and purification by a 4-stage centrifugal extraction method, and filtering to obtain a decontaminated leaching solution.

[0052] In the present application, after the pressure leaching reaction is sufficient, the pressure leaching solution obtained by filtration is transported to the impurity removal device, the pH of the pressure leaching solution is adjusted to 1-2, and the temperature is ≤55°C, LIX extractant is added, and a 4-stage centrifugal extraction method is used for copper removal and purification, filtration, solid-liquid separation, and impurity-removed leaching solution, that is, a sulfate solution of the target metal, is obtained. Among them, the organic ratio of the 4-stage centrifugal extraction method is LIX extractant: solvent oil = (20% to 30%): (70% to 80%).

[0053] In summary, the method provided by the present invention has the following advantages:

[0054] 1) By adding a certain amount of concentrated sulfuric acid for pre-activation at the second grinding node, the oxidizing property of concentrated sulfuric acid and the mechanical strength and friction heat in the grinding process are used for pre-activation, which can accelerate the oxidation reaction of sulfides in sulfide ore and accelerate the subsequent leaching of target metals in sulfide ore.

[0055] 2) In atmospheric pressure leaching, the secondary ground material is leached at atmospheric pressure using a relatively high concentration of sulfuric acid solution, which accelerates the oxidation reaction of sulfides in sulfide minerals and the leaching reaction efficiency of elemental metals in sulfide minerals.

[0056] 3) This method is equipped with an ultrasonic super oxidizer for dispersing oxygen for atmospheric pressure leaching. The ultrasonic wave of the ultrasonic super oxidizer is used to greatly increase the dispersion effect of oxygen, and relatively high-purity oxygen is introduced, and the material is ground to a particle size of about 40 microns by secondary grinding, which increases the specific surface area of ​​the material and the contact area with oxygen, thereby greatly increasing the reaction rate of atmospheric pressure oxidation of sulfides and the leaching rate of the target metal.

[0057] 4) Accurate batching is achieved during the atmospheric pressure leaching reaction batching process. The alkaline characteristic of the material itself to consume hydrogen ions is utilized, and the material itself is used as a neutralizing agent to carry out neutralization and hydrolysis to remove iron and purify the reaction. The content of impurities such as iron in the atmospheric pressure leaching solution is extremely small, which shortens the process flow, reduces the addition of auxiliary materials, and reduces the processing cost of sulfide ore.

[0058] 5) Compared with the conventional method in which the pressurized leaching equipment uses a horizontal stirring device for pressurized leaching, the solution of the present application greatly increases the reaction rate of atmospheric oxidation of sulfides and the leaching rate of the target metal, thereby reducing the number of high-pressure reaction equipment configured in the pressurized leaching stage and reducing the leaching and purification cost of sulfide minerals. Among them, compared with the conventional method, the method of the present invention can reduce the number of high-pressure reaction equipment configured by more than 60%. And the pressurized oxidation leaching and purification process flow of sulfide ore treatment is greatly compressed, the consumption of auxiliary materials is greatly reduced, and the processing cost of sulfide ore is reduced.

[0059] In order to demonstrate the advantages of the method provided by the present invention, it is described below in conjunction with specific embodiments.

[0060] Example 1

[0061] The sulfide mineral is a copper-cobalt sulfide ore containing 13.7% copper, 6% cobalt, 15.2% iron and 12.6% sulfur.

[0062] 1) 4.05t of sulfide mineral particles are firstly ground in a ball mill, and the particle size D90 of the material after the first grinding is 80 microns, and then ground in a tube mill, and the particle size D90 of the material after the second grinding is 40 microns; and concentrated sulfuric acid of 1.0% of the weight of the copper-cobalt sulfide ore is added in the second grinding node through pipeline transportation and spraying. The concentration of the concentrated sulfuric acid is 1800g / L, and the adding speed of the concentrated sulfuric acid is 0.2t / h.

[0063] 2) The secondary ground material is transported to a 6.5 mL container containing a 100 g / L sulfuric acid solution. 3 The reaction vessel was maintained at a temperature of 60°C, stirred at a stirring rate of 50 r / min, and stirred at a stirring rate of 10 Nm 3 Oxygen (purity>90%) was introduced at a rate of / h to carry out normal pressure leaching reaction for 4 hours to obtain normal pressure leaching slurry.

[0064] The device for introducing oxygen is an ultrasonic super-energy oxidizer, which is connected to an oxygen gas source and communicated with the bottom of the atmospheric pressure leaching device;

[0065] The oxygen is introduced in the following manner: the ultrasonic super-energy oxidizer mixes the slurry of the secondary ground material and sulfuric acid solution flowing out of the upper part of the atmospheric pressure leaching device with the introduced oxygen, and then injects it into the atmospheric pressure leaching device from the bottom of the atmospheric pressure leaching device to make the oxygen fully contact with the material.

[0066] 3) After the atmospheric pressure leaching reaction is completed, the atmospheric pressure leaching slurry is transported to the atmospheric pressure leaching slurry filtration device for solid-liquid separation to obtain atmospheric pressure leaching liquid 5m 3And atmospheric pressure leaching residue. Among them, the atmospheric pressure leaching solution is copper cobalt sulfate solution, pH 5.0, copper concentration 17.95g / L, iron concentration 0.012g / L, cobalt concentration 8.10g / L, atmospheric pressure copper leaching rate 62.3%, atmospheric pressure cobalt leaching rate 64.2%.

[0067] 4) The atmospheric pressure leaching residue is treated with 6.5 mL of 50 g / L sulfuric acid solution. 3 After slurrying, it is transported to the pressure leaching reactor; the gas pressure in the pressure oxidation leaching reactor is increased and maintained at 1.4Mpa with high-pressure oxygen (purity>90%), and the initial temperature of the pressure leaching reaction is increased to 120°C. The pressure leaching reaction begins to react violently, and the reaction temperature is maintained by the heat release of the reaction itself until the pressure oxidation reaction ends. After reacting for 5 hours, filter to obtain pressure leaching liquid and pressure leaching residue. Among them, the pressure leaching liquid 5m 3 , copper concentration is 10.61g / L, cobalt concentration is 4.29g / L, pressurized copper leaching rate is 36.9%, pressurized cobalt leaching rate is 34.1%. The combined copper leaching rate under normal pressure and pressurized is 99.2%, and the combined cobalt leaching rate under normal pressure and pressurized is 98.3%.

[0068] Example 2

[0069] The sulfide mineral is high nickel matte containing 71% nickel, 1% iron and 20% sulfur.

[0070] 1) 4.05t of sulfide mineral particles are first ground by a Raymond mill, and the particle size D90 of the material after the first grinding is 70 microns. Then, a vibration mill is used for the second grinding, and the particle size D90 of the secondary ground material is 30 microns. Concentrated sulfuric acid of 5% by weight of high nickel matte is added in the second grinding node by pipeline spraying, wherein the concentration of the concentrated sulfuric acid is 1800g / L, and the addition rate of the concentrated sulfuric acid is 0.3t / h.

[0071] 2) The secondary ground material is transported to a 24-mL container containing a 120 g / L sulfuric acid solution. 3 The reaction vessel was maintained at a temperature of 85°C, stirred at a stirring rate of 120 r / min, and stirred at a speed of 60 Nm 3 Oxygen (purity>90%) was introduced at a rate of / h to carry out normal pressure leaching reaction for 4 hours to obtain normal pressure leaching slurry.

[0072] The device for introducing oxygen is an ultrasonic super-energy oxidizer, which is connected to an oxygen gas source and communicated with the bottom of the atmospheric pressure leaching device;

[0073] The oxygen is introduced in the following manner: the ultrasonic super-energy oxidizer mixes the slurry of the secondary ground material and sulfuric acid solution flowing out of the upper part of the atmospheric pressure leaching device with the introduced oxygen, and then injects it into the atmospheric pressure leaching device from the bottom of the atmospheric pressure leaching device to make the oxygen fully contact with the material.

[0074] 3) After the atmospheric pressure leaching reaction is completed, the atmospheric pressure leaching slurry is transported to the atmospheric pressure leaching slurry filtration device for solid-liquid separation to obtain 20m atmospheric pressure leaching liquid 3 And atmospheric pressure leaching residue. Among them, the atmospheric pressure leaching solution is a nickel sulfate solution with a pH of 5.1, a nickel concentration of 91.81 g / L, an iron concentration of 0.011 g / L, and an atmospheric pressure nickel leaching rate of 64.0%.

[0075] 4) The atmospheric pressure leaching residue is treated with 18 ml of sulfuric acid solution with a concentration of 80 g / L. 3 After slurrying, it is transported to the pressure leaching reactor; high-pressure oxygen (purity> 90%) is used to increase the gas pressure in the pressure oxidation leaching reactor and maintain it at 1.8Mpa, and the initial temperature of the pressure leaching reaction is increased to 140°C. The pressure leaching reaction begins to react violently, and the reaction temperature is maintained by the heat release of the reaction itself until the pressure oxidation reaction is completed. After the pressure leaching time is 2h, the pressure leaching liquid and pressure leaching residue are obtained by filtration. After the reaction is completed, filter to obtain the pressure leaching liquid and pressure leaching residue. Among them, the pressure leaching liquid 15m 3 , nickel concentration is 68.99g / L, iron concentration is 0.007g / L, and the nickel leaching rate at normal pressure is 35.4%. The combined nickel leaching rate at normal pressure and pressurized pressure is 99.4%.

[0076] 5) The pressurized leaching solution is transported to the impurity removal reactor, the reaction pH is maintained at 1.2 and the reaction temperature is maintained at 50°C, LIX extractant is added, and copper is removed and purified by a 4-stage centrifugal extraction method, filtered, and solid-liquid separated to obtain an impurity-removed leaching solution. The organic ratio in the 4-stage centrifugal extraction method is LIX extractant: 30%; solvent oil: 70%. The copper concentration in the impurity-removed leaching solution is 0.01 g / L.

[0077] Example 3

[0078] Sulfide mineral: Copper-cobalt alloy containing 65% copper, 2.5% cobalt, 24.66% iron and 3% sulfur.

[0079] Extraction equipment: same as in Example 1.

[0080] Extraction steps: same as Example 1.

[0081] Design parameters: The amount of concentrated sulfuric acid added is 5% of the weight of the copper-cobalt alloy, the concentration of the atmospheric pressure leaching sulfuric acid solution is 170g / L, and the amount added is 25m 3 , the atmospheric pressure leaching time is 2h, and other design parameters are the same as those in Example 1.

[0082] Test results: atmospheric pressure leaching solution 20m 3 , containing 118.56g / L copper and 4.54g / L cobalt. The normal pressure copper leaching rate is about 90.1%, and the normal pressure cobalt leaching rate is 89.8%.

[0083] Detection of pressurized leaching liquid 20m 3 The copper content is 12.24g / L, the cobalt content is 0.47g / L, the pressure copper leaching rate is 9.3%, the pressure cobalt leaching rate is 9.3%. The comprehensive copper leaching rate under normal pressure and pressure is 99.4%, and the comprehensive cobalt leaching rate is 99.1%.

[0084] Example 4

[0085] Sulfide minerals: Nickel sulfide ore containing 53% nickel, 0.5% copper, 4% iron and 28% sulfur.

[0086] Extraction equipment: same as in Example 2.

[0087] Extraction steps: same as Example 2.

[0088] Design parameters: The amount of concentrated sulfuric acid added is 5% of the weight of the nickel sulfide ore, the concentration of the atmospheric pressure leaching sulfuric acid solution is 100g / L, and the amount added is 21m 3 The atmospheric pressure leaching time is 13 h, and other design parameters are the same as those in Example 2.

[0089] Test results: atmospheric pressure leaching solution 15m 3 It contains 87.59 g / L nickel, the nickel leaching rate at normal pressure is about 61.2%, and the iron concentration is 0.008 g / L.

[0090] Pressurized leaching liquid 15m 3 The nickel content is 55.53g / L, the pressure nickel leaching rate is 37.0%, and the combined pressure and pressure nickel leaching rate is 98.2%.

[0091] The copper concentration in the impurity-removing leaching solution was detected to be 0.01 g / L.

[0092] Example 5

[0093] Sulfide minerals: low-grade nickel matte containing 31.08% nickel, 35% iron and 27% sulfur.

[0094] Extraction equipment: same as in Example 2.

[0095] Extraction steps: same as Example 2.

[0096] Design parameters: The amount of concentrated sulfuric acid added is 5% of the weight of the nickel matte, the concentration of the atmospheric pressure leaching sulfuric acid solution is 102g / L, and the amount added is 19m 3 , the atmospheric pressure leaching time is 2h, and other design parameters are the same as those in Example 2.

[0097] Test results: atmospheric pressure leaching solution 15m 3 It contains 52.31 g / L nickel, the nickel leaching rate at normal pressure is about 62.4%, and the iron concentration is 0.009 g / L.

[0098] Pressurized leaching liquid 15m 3 The nickel content is 31.46g / L, the pressure nickel leaching rate is 35.1%, and the combined nickel leaching rate under normal pressure and pressure is 97.5%.

[0099] The copper concentration in the impurity-removing leaching solution was detected to be 0.01 g / L.

[0100] Comparative Example 1

[0101] Sulfide minerals: High nickel matte containing 71% nickel, 1% iron and 20% sulfur.

[0102] Extraction equipment: same as in Example 2.

[0103] Extraction step: During the second stage of grinding, concentrated sulfuric acid was not added for pre-activation, and the other steps were the same as in Example 2.

[0104] Design parameters: The concentration of the atmospheric pressure leaching sulfuric acid solution was adjusted to 204 g / L to make the total sulfuric acid concentration added consistent. Other design parameters were the same as in Example 2.

[0105] Test results: atmospheric pressure leaching solution 20m 3 The nickel content is 73.48 g / L, and the atmospheric pressure nickel leaching rate is 51.1%. Compared with Example 2, it is 12.9% lower than the same period last year.

[0106] Comparative Example 2

[0107] Sulfide minerals: High nickel matte containing 71% nickel, 1% iron and 20% sulfur.

[0108] Extraction equipment: same as in Example 2.

[0109] Extraction steps: same as Example 2.

[0110] Design parameters: The particle size of the high nickel matte after secondary grinding meets the requirements, and the particle size D90 is 80 microns. Other design parameters are the same as those in Example 2.

[0111] Test results: atmospheric pressure leaching solution 20m 3 The nickel content is 69.01 g / L, and the atmospheric pressure nickel leaching rate is 48.0%. Compared with Example 2, it is 16.0% lower than that of Example 2.

[0112] Comparative Example 3

[0113] Sulfide minerals: High nickel matte containing 71% nickel, 1% iron and 20% sulfur.

[0114] Extraction equipment: The atmospheric pressure leaching device is not equipped with an ultrasonic super-energy oxidizer, but a conventional mechanical stirring leaching device.

[0115] Extraction steps: same as Example 2.

[0116] Design parameters: same as Example 2.

[0117] Test results: atmospheric pressure leaching solution 20m 3 The nickel content is 62.24 g / L, and the nickel leaching rate at normal pressure is about 43.3%. Compared with Example 2, it is 20.7% lower than that of Example 2.

[0118] Table 1 Leaching rate of target metal in each embodiment and comparative example

[0119]

[0120]

[0121] As explained in conjunction with Table 1, it can be seen from Example 2 and Comparative Examples 1 to 3 that in the method of the present application, the use of concentrated sulfuric acid solution for pre-activation in the grinding stage, the grinding of the particle size of the sulfide mineral to D90 < 40 microns, and the use of an ultrasonic super-energy oxidizer to fully disperse oxygen in the atmospheric pressure leaching stage can effectively improve the leaching rate of the target leaching in the atmospheric pressure leaching stage, and the comprehensive leaching rate of the target metal in the sulfide mineral can be guaranteed while simplifying the pressurized leaching equipment. Thereby reducing the energy consumption and cost in the extraction process, as well as the safety hazards of the production process. Further, it can be seen from Examples 1 to 5 that the method of the present application is suitable for extracting target metals from a variety of sulfide minerals, and the leaching rate in the atmospheric pressure leaching stage can reach more than 62%, and the comprehensive leaching rate can reach more than 97.8%.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for leaching sulfide minerals, characterized in that: The leaching method comprises: S1, grinding the sulfide mineral for a second time, and adding concentrated sulfuric acid to the second grinding for pre-activation to obtain a second-grinded material; S2, adding the secondary ground material into a sulfuric acid solution, performing normal pressure leaching, and obtaining a normal pressure leaching slurry; wherein at least one of stirring, introducing oxygen, and maintaining the normal pressure leaching temperature is performed during the normal pressure leaching process; S3, filtering the atmospheric pressure leaching slurry to obtain atmospheric pressure leaching residue and atmospheric pressure leaching liquid; S4, adding the atmospheric leaching residue into a sulfuric acid solution for slurrying, and then performing pressure leaching, and performing at least one of the operations of introducing oxygen, adjusting the air pressure, and adjusting the initial temperature of the pressure leaching during the pressure leaching process, filtering after sufficient reaction, to obtain pressure leaching residue and pressure leaching solution.

2. The sulfide mineral leaching method according to claim 1, characterized in that: After S4, the leaching method further comprises: S5, performing impurity removal treatment on the pressurized leaching solution, and filtering to obtain the impurity-removed leaching solution.

3. The leaching method of sulfide minerals according to claim 1 or 2, characterized in that: In S1, The secondary grinding comprises first grinding and then second grinding; concentrated sulfuric acid is added in the second grinding for pre-activation; The particle size D90 of the material after the first grinding is less than 80 microns, and the particle size D90 of the material after the second grinding is less than 40 microns; The concentration of the concentrated sulfuric acid in the S1 is 1400-1800 g / L, and the amount of the concentrated sulfuric acid added is 1.0-5.5% of the weight of the sulfide mineral; the addition rate of the concentrated sulfuric acid is 0.1-0.5 t / h; the concentrated sulfuric acid is added by pipeline transportation and spraying.

4. The leaching method of sulfide minerals according to claim 3, characterized in that: The first stage of grinding uses a ball mill or a Raymond mill for coarse grinding, and the second stage of grinding uses a tube mill, a vibration mill or a mechanical stirring mill for fine grinding.

5. The leaching method of sulfide minerals according to claim 1 or 2, characterized in that: In S2, the sulfuric acid concentration in the sulfuric acid solution is 100 g / L-160 g / L; In S4, the concentration of sulfuric acid in the sulfuric acid solution is 10 g / L-100 g / L.

6. The leaching method of sulfide minerals according to claim 5, characterized in that: In S2, The device for the normal pressure leaching reaction is a normal pressure leaching device; The oxygen introduction rate is 10-60Nm 3 / h, and the purity of the oxygen is greater than 90%; The device for introducing oxygen is an ultrasonic super-energy oxidizer, which is connected to an oxygen source and communicated with the bottom of the normal pressure leaching device; The oxygen is introduced in the following manner: the ultrasonic super-energy oxidizer mixes the slurry of the secondary ground material and the sulfuric acid solution flowing out of the upper part of the atmospheric pressure leaching device with the introduced oxygen, and then injects the slurry into the atmospheric pressure leaching device from the bottom of the atmospheric pressure leaching device.

7. The leaching method of sulfide minerals according to claim 6, characterized in that: In S2, The stirring rate is 50-120r / min; The atmospheric pressure leaching temperature is maintained at 60-90°C; The normal pressure leaching time is 2-13h.

8. The sulfide mineral leaching method according to claim 1 or 2, characterized in that: In S4, The slurrying time is 0.5-2h; Using the oxygen to pressurize and maintain the gas pressure at 1.4-1.8Mpa, and the purity of the oxygen is greater than 90%; Adjusting the initial temperature of the pressure leaching to 120-140° C.; The pressure leaching time is 2-5h.

9. The method for leaching sulfide minerals according to any one of claims 1, 2, 6 or 7, characterized in that: The sulfide mineral is at least one or more of nickel sulfide ore, copper-cobalt sulfide ore, cobalt-copper alloy, high nickel matte, and low nickel matte.

10. The leaching method of sulfide minerals according to claim 9, characterized in that: When the sulfide mineral is at least one or more of nickel sulfide ore, high nickel matte, and low nickel matte, S5 specifically comprises: adjusting the pH and temperature of the pressurized leaching solution, adding LIX extractant, performing copper removal and purification by a 4-stage centrifugal extraction method, and filtering to obtain a decontaminated leaching solution.

11. The sulfide mineral leaching method according to claim 10, characterized in that: In S5, the pH of the pressurized leaching solution is maintained at 1-2; The temperature of the pressurized leachate is maintained at ≤55°C; The organic ratio of the four-stage centrifugal extraction method is LIX extractant: solvent oil = (20% to 30%): (70% to 80%).

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