Method for recovering and enriching precious metal in low-grade precious metal complex material

Abstract

The invention relates to the technical field of precious metal recovery, and discloses a method for recovering and enriching precious metal in a low-grade precious metal complex material. The method comprises the following steps: pretreating a mineral material, dissolving the precious metal by using a leaching agent under the control of temperature and time, introducing a catalyst to promote a dissolution reaction, and monitoring and adjusting reaction conditions in real time. And finally, the dissolved noble metal ions are extracted, so that the recovery efficiency is improved and the energy consumption is reduced. The invention further provides a system for recovering and enriching the precious metal in the low-grade precious metal complex material. The system comprises a pretreatment module, a leaching module, a real-time monitoring module, an extraction module and a control system module. Through the combination of integrated pretreatment, leaching, real-time monitoring, catalyst optimization and multiple extraction technologies, the recovery efficiency and purity of the precious metal are remarkably improved; compared with the prior art, the problems of low precious metal dissolution rate, inaccurate reaction control, high energy consumption, insufficient recovery purity and the like are solved, and high-efficiency and low-cost recovery is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of precious metal recovery, and in particular to a method for recovering and enriching precious metals in low-grade precious metal complex materials. Background Art

[0002] In the process of precious metal recovery, the treatment of low-grade ores has always been a difficult problem; traditional precious metal dissolution methods often rely on high temperature and strong acidic solutions, which not only increases energy consumption, but also imposes a heavy burden on the environment; in addition, dissolution reactions under high temperature conditions often lead to limited precious metal dissolution rates and may cause uncontrollable side reactions; this makes the recovery of many low-grade precious metal ores uneconomical and environmentally unfriendly; the dissolution processes in the existing technologies generally lack precise control over reaction conditions, resulting in the recovery efficiency and purity of precious metals cannot be fully guaranteed.

[0003] The leaching methods in the prior art usually rely on fixed reaction conditions, such as leaching agent concentration and temperature, which results in poor stability of the recovery effect under different ore types and precious metal contents; although the use of catalysts can increase the dissolution rate, the catalyst application in the prior art often does not have dynamic adjustment capabilities and cannot optimize the catalyst concentration according to the real-time reaction progress; this makes the use of catalysts often wasteful or incomplete, and cannot achieve the best recovery effect.

[0004] In addition, the existing technology in the extraction process usually relies on a single extraction method, such as solvent extraction, precipitation or electrolysis; although these methods are effective individually, they are often difficult to cope with all challenges alone in the process of complex mineral dissolution; especially when processing low-grade ores, a single method may not be able to efficiently separate precious metal ions, resulting in low recovery rate or low purity; therefore, the present invention proposes a method for recovering and enriching precious metals in low-grade precious metal complex materials to address the shortcomings of the existing technology. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for recovering and enriching precious metals in low-grade precious metal complex materials, which solves the problems of slow precious metal dissolution rate, low recovery efficiency, high energy consumption and lack of precise control during the recovery process.

[0006] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for recovering and enriching precious metals in low-grade precious metal complex materials, comprising the following steps: S1. Pre-treating low-grade precious metal complex materials to obtain precious metal-containing ore pulp; S2, contacting the slurry with the leaching agent, and performing a dissolution reaction under reaction temperature and reaction time conditions; S3, introducing a catalyst to promote the dissolution reaction of precious metals; S4, adjusting the reaction conditions by real-time monitoring of the progress of the dissolution reaction; S5. extracting the dissolved precious metal ions.

[0007] Preferably, the catalyst is molybdenum, cobalt or copper, and the concentration of the catalyst is 0.1% to 5%.

[0008] Preferably, the leaching agent is cyanide or chloride, and the concentration of the leaching agent is 0.01M to 1M.

[0009] Preferably, in the dissolution reaction, the dissolution rate of the noble metal follows the Arrhenius equation, the reaction rate constant varies with temperature, and the reaction activation energy is reduced by the introduction of a catalyst; The dissolution reaction rate follows the Arrhenius equation, and the reaction rate constant With temperature The relationship is: ; in: is the reaction rate constant; is the pre-exponential factor, which represents the collision frequency between reactants; It is the base of natural logarithms, also called Euler's number; is the activation energy of the reaction, in J / mol; is the gas constant, J / mol\cdotpK; is the reaction temperature in K.

[0010] Preferably, the Gibbs free energy change in the dissolution reaction is The spontaneous dissolution conditions are met, where ; Gibbs free energy change It can be calculated by the following formula: ; in: is the Gibbs free energy change of the reaction; is the enthalpy change of the reaction; is temperature; is the entropy change of the reaction.

[0011] Preferably, the progress of the dissolution reaction is monitored in real time by a sensor, and the reaction conditions including temperature, leaching agent concentration and catalyst concentration are adjusted.

[0012] Preferably, the noble metal ions in the dissolution reaction are separated from the solution by solvent extraction.

[0013] Preferably, the precious metal complex material includes gold and silver, and its precious metal content is less than 5 g / t.

[0014] Preferably, the pretreatment includes screening, grinding and chemical treatment steps, wherein screening is used to remove larger particles of minerals, grinding is used to refine the mineral particles to a particle size suitable for leaching, and chemical treatment uses an acid leaching method to remove impurity minerals that affect the dissolution reaction.

[0015] The present invention also provides a system for recovering and enriching precious metals in low-grade precious metal complex materials, comprising: Pretreatment module, used to process low-grade precious metal complex materials and obtain precious metal-containing slurry; A leaching module, including a leaching agent supply device, a temperature control device, and a catalyst supply device, for promoting the dissolution reaction of precious metals under low temperature conditions; Real-time monitoring module, used to monitor the progress of precious metal dissolution reaction, and adjust temperature, leaching agent concentration and catalyst concentration; An extraction module, used for extracting dissolved precious metal ions from the solution; The control system module coordinates the work of each module and adjusts the reaction conditions to ensure the recovery efficiency of precious metals.

[0016] The present invention provides a method for recovering and enriching precious metals in low-grade precious metal complex materials. It has the following beneficial effects: 1. The present invention adopts the technical solution of integrated pretreatment module, leaching module and real-time monitoring module to achieve efficient recovery of precious metals; through precise pretreatment of low-grade precious metal minerals, the optimized exposure of precious metal mineral particles is ensured, making the leaching reaction more sufficient; compared with the single leaching process in the prior art, the problem of low precious metal dissolution rate is often caused by insufficient pretreatment of minerals. The present invention solves this problem and significantly improves the recovery efficiency of precious metals.

[0017] 2. The present invention adopts a technical solution of dynamically adjusting the noble metal dissolution reaction process by a real-time monitoring system, thereby achieving the technical effect of optimizing the reaction conditions; by monitoring the temperature, leaching agent concentration and catalyst concentration, the system can automatically adjust according to the progress of the reaction to ensure that the reaction is always in the best state; compared with the traditional technology that lacks precise control of reaction conditions, the present invention effectively avoids the waste of resources caused by excessively high temperature or too low leaching agent concentration, and improves the accuracy and stability of the reaction.

[0018] 3. The present invention adopts catalyst optimization addition technology, using catalysts such as molybdenum, cobalt, and copper to reduce the activation energy of the reaction and increase the dissolution rate of precious metals; through the introduction of catalysts, the reaction can be carried out efficiently at a lower temperature. Compared with the reliance on energy consumption for high-temperature operation in the prior art, the present invention significantly reduces energy consumption, reduces environmental impact, and achieves efficient use of energy.

[0019] 4. The present invention achieves the recovery effect of high-purity precious metals through a combination of various precious metal extraction technologies such as solvent extraction, precipitation and electrolysis; the technical solution flexibly selects different extraction methods, which not only improves the recovery rate of precious metals, but also ensures the purity of the final recovered metals; compared with the single extraction method in the prior art, which often faces the problem of low precious metal recovery efficiency or low purity, the present invention solves these technical bottlenecks and ensures efficient and low-cost recovery of precious metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the method of the present invention; Figure 2 It is a system architecture diagram of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] See also Figure 1 The embodiment of the present invention provides a method for recovering and enriching precious metals in low-grade precious metal complex materials, comprising the following steps: S1. Pre-treating low-grade precious metal complex materials to obtain precious metal-containing ore pulp; When recovering precious metals from complex materials enriched with low-grade precious metals, the pretreatment step is crucial in the entire recovery process; it determines whether the precious metals can be efficiently dissolved in the subsequent leaching reaction and lays the foundation for the final extraction of the precious metals; specifically, the goal of pretreatment is to remove impurities in the minerals and refine the ore through physical and chemical methods to increase the exposed area of ​​the precious metal minerals, thereby improving the efficiency and recovery rate of the subsequent leaching reaction.

[0023] In this embodiment, the pretreatment process mainly includes steps such as screening, grinding and possible chemical treatment to ensure that the ore can meet the particle size required by the leaching reaction and remove unnecessary impurities.

[0024] Screening is the first step in pretreatment, and its purpose is to remove larger particles in the ore to ensure that the mineral can fully contact the leaching agent during the subsequent reaction process; screening equipment usually includes vibrating screens, drum screens, etc.; after the minerals are screened, materials of different particle sizes are divided into several categories, and larger particles can be further processed by grinding.

[0025] The principle of the screening process is to selectively separate mineral particles through the aperture of the screen, so that smaller particles can better contact with the leaching agent, avoiding the presence of large particles resulting in long or uneven reaction time; the screening particle size range is usually 80 mesh to 200 mesh; in order to ensure efficient leaching reaction, the ore is generally screened to a fine particle size that is more suitable for dissolution.

[0026] The purpose of the grinding process is to grind the ore particles to a suitable particle size to increase the specific surface area of ​​the precious metal minerals, thereby improving the efficiency of the dissolution reaction; through grinding, the surface of the mineral particles is more easily exposed to the leaching agent, and the precious metal components can also be more easily dissolved into the leaching solution.

[0027] In this embodiment, grinding can be performed by a ball mill or a rod mill; the particle size requirement for grinding is generally between 80 mesh and 200 mesh, and the specific particle size requirement is related to the hardness of the ore, the precious metal content and the requirements of the subsequent leaching reaction; the grinding time is usually controlled between 30 minutes and 3 hours. The finer the grinding, the larger the exposure area of ​​the precious metal, but it will also lead to increased energy consumption, so the grinding time needs to be optimized according to the properties of the ore.

[0028] Generally, the grinding fineness ranges from 80-200 mesh; for some particularly hard ores, the grinding time may be appropriately extended to ensure that the precious metal components are fully exposed.

[0029] In some embodiments, in addition to physical screening and grinding, chemical treatment methods (such as acid leaching or oxidation treatment) can also be used to remove unwanted impurities in the ore; for example, some minerals may contain sulfides, iron minerals, etc., and these impurities may react with precious metals during the subsequent leaching process, affecting the dissolution of precious metals; these impurities can be removed by pre-treating the ore with an appropriate acid solution (such as sulfuric acid, hydrochloric acid, etc.).

[0030] For example, sulfur in sulfide ores can be converted into soluble sulfates through oxidation reactions, and iron minerals can be removed through acid leaching; these chemical treatments can effectively remove impurities and reduce interference with the dissolution process of precious metals.

[0031] Specifically, the acid leaching process involves mixing the ore with an acid solution (such as sulfuric acid) and maintaining a certain reaction time and temperature to ensure the removal of impurities. The chemical reaction formula of the acid leaching reaction can be shown as follows: ; in: It is iron sulfide in ore; for oxygen; For water; for dissolved iron sulfate; The sulfuric acid generated; In this reaction, the oxidation of sulfides can promote the cleaning of ore and reduce the impact on precious metal recovery in the subsequent leaching process.

[0032] After screening, grinding and necessary chemical treatment, the resulting slurry is a fine-grained mineral-liquid mixture containing precious metals. At this point, the precious metals in the mineral have been exposed and can fully contact with the subsequent leaching agent, thus laying the foundation for the leaching reaction.

[0033] The concentration of the slurry usually needs to be adjusted according to the requirements of the reaction. Generally speaking, the concentration range of the slurry is 10%-50%. The setting of the slurry concentration is closely related to the type of ore, the content of precious metals and the solvent concentration required for the subsequent reaction. Too high a slurry concentration may lead to insufficient contact between the leaching agent and the mineral, while too low a concentration may affect the economic efficiency of the leaching reaction. Therefore, the concentration of the slurry should be determined based on experiments and industrial practice.

[0034] In step S1, some of the physical and chemical principles involved can be further explained by formulas; in the grinding and screening process, the optimization of particle size is one of the key steps; according to the relationship between particle size and reaction efficiency, the increase in exposed surface area during particle size refinement can be quantified by the following formula: ; in: is the surface area of ​​the particle (unit: cm 2 ); is the diameter of the particle (unit: cm).

[0035] This formula shows that the surface area of ​​the particles is inversely proportional to the particle diameter, that is, the smaller the particle, the larger its exposed surface area, which is conducive to the subsequent leaching reaction.

[0036] For the acid leaching process, the removal of some minerals can be achieved through chemical reactions. Here, the chemical reaction rate equation is used to describe the progress of the reaction; assuming that the dissolution process of the ore is a first-order reaction, it can be described by the following equation: ; in: Indicates the concentration of chemical substances Over time The rate of change of the substance in the chemical reaction The rate of change of concentration; is the concentration of a substance in the ore during the dissolution process; is the reaction rate constant; For time; During the acid leaching process, this equation can be used to describe the dissolution rate of certain impurity components in the ore in an acidic environment.

[0037] S2, contacting the slurry with the leaching agent, and performing a dissolution reaction under reaction temperature and reaction time conditions; In step S1, through screening, grinding and necessary chemical treatment, the precious metals in the ore have been exposed and are ready to react with the leaching agent; the core task of step S2 is to achieve the dissolution of the precious metals under precisely controlled reaction temperature and reaction time conditions by contacting the slurry with a suitable leaching agent; this process is the key to the entire precious metal recovery process and directly determines the dissolution rate of the precious metals and the efficiency of subsequent extraction.

[0038] In this embodiment, the dissolution rate of the precious metal is first optimized by selecting a suitable leaching agent, temperature and reaction time; by precisely controlling these conditions, we can ensure that the precious metal is efficiently dissolved from the mineral without wasting energy and leaching agents; temperature and reaction time are two important factors in controlling the reaction rate.

[0039] Reaction temperature is closely related to reaction time. A reasonable ratio of temperature and time can significantly improve the dissolution efficiency of precious metals. Too low a temperature may result in a slow dissolution rate, affecting the extraction of precious metals, while too high a temperature may lead to rapid consumption of the leaching agent and the occurrence of side reactions.

[0040] In some embodiments, the reaction temperature is generally selected within the range of 30°C to 50°C, and the specific selected temperature range is determined based on the type of ore, the type of precious metal and its mineral composition; this temperature range can ensure a balance between the dissolution rate of precious metal minerals and energy consumption; lower temperatures can reduce energy consumption and reduce undesirable side reactions, such as dissolving too much impurity minerals; higher temperatures can accelerate the dissolution of precious metals, but may cause the solvent to be consumed too quickly, and the dissolution rate of some precious metals does not increase linearly with increasing temperature.

[0041] The choice of reaction time is also crucial; generally, the reaction time ranges from 2 hours to 48 hours, adjusted according to the properties of the ore and the reaction temperature; a shorter reaction time may result in incomplete dissolution of the precious metals, while a reaction time that is too long may cause impurities in the solution to dissolve, affecting the extraction effect of the precious metals; therefore, the reaction time must be adjusted through experiments and industrialization to ensure efficient and economical recovery of precious metals.

[0042] The choice of leaching agent plays a decisive role in the effect of the reaction; usually, cyanide and chloride are commonly used leaching agents for recovering precious metals, especially gold and silver; cyanide is often used to treat gold ore, while chloride is suitable for silver ore or the treatment of some composite precious metal ores.

[0043] The concentration of cyanide is usually selected between 0.01M and 1M; higher concentrations of cyanide help accelerate the dissolution of precious metals, but they also need to be controlled to prevent excessive consumption of cyanide or side reactions; the coordination of cyanide concentration and temperature plays an important role in the dissolution of metals. Generally, the most commonly used cyanide concentration for the dissolution reaction of gold ore is 0.1M to 0.5M.

[0044] Chlorides, especially sodium chloride and hydrogen chloride, can be used as leaching agents to dissolve silver ore; in silver ore processing, the chloride concentration is generally maintained between 0.01M and 0.1M; for complex ores where gold and silver coexist, cyanide and chloride are usually mixed according to the metal content and ore type to optimize the dissolution effect.

[0045] When the concentration of the leaching agent is too low, it may not be able to effectively dissolve the precious metals, while when the concentration is too high, it may cause waste of the leaching agent and may introduce unnecessary impurities in the subsequent precious metal extraction process.

[0046] In order to increase the dissolution rate of precious metals, the present invention reduces the activation energy of the reaction by adding a catalyst, thereby further accelerating the dissolution of the precious metals; the role of the catalyst in low-temperature reactions is very significant, and it can promote the reaction of precious metal minerals and leaching agents at lower temperatures, thereby reducing the demand for energy at high temperatures.

[0047] In this embodiment, commonly used catalysts include transition metals such as molybdenum, cobalt, copper and their alloys; the catalyst concentration is usually between 0.1% and 5% (w / w); by introducing the catalyst, the rate constant of the dissolution reaction is increased, thereby significantly improving the dissolution rate of the precious metal.

[0048] The mechanism of action of the catalyst can be described by the Arrhenius equation. The catalyst reduces the activation energy of the reaction. The reaction can proceed rapidly at a lower temperature; according to the Arrhenius equation, the reaction rate constant With temperature The relationship is: ; in: is the reaction rate constant; is the pre-exponential factor, which represents the collision frequency between reactants; It is the base of natural logarithms, also called Euler's number; is the activation energy of the reaction, in J / mol; is the gas constant, J / mol\cdotpK; is the reaction temperature in K.

[0049] The catalyst reduces , making the reaction between precious metal minerals and leaching agents faster; the selection of catalysts is crucial to improving the dissolution reaction rate, which can significantly reduce energy consumption and optimize the recovery process.

[0050] In actual operation, the reaction in step S2 needs to be monitored in real time to ensure that the reaction conditions are always in the optimal state; the monitoring system usually includes a temperature sensor, a leaching agent concentration detector and a catalyst concentration measuring device; through these real-time monitoring devices, the reaction temperature, the leaching agent concentration in the solution and the catalyst concentration can be monitored to ensure the stability of the reaction process.

[0051] In some embodiments, the data obtained by the sensor can be fed back to the reaction control system in real time, and the system can automatically adjust the reaction temperature, leaching agent concentration and catalyst concentration according to the feedback results; for example, when the reaction temperature is low, the control system can appropriately increase the temperature to speed up the dissolution of precious metals; if the leaching agent concentration is too low, the system can increase the amount of leaching agent added according to the data prompts, thereby maintaining the stability of the reaction rate.

[0052] The chemical formula for the dissolution reaction is: ; in, It is a precious metal mineral, such as gold (Au), silver (Ag), platinum (Pt), etc. This symbol represents a solid precious metal ore; It is an oxygen molecule, an oxidant that participates in the redox reaction; in the reaction, the oxygen molecule reacts with the precious metal mineral; is the oxygen molecule number coefficient, indicating the number of oxygen molecules required for each noble metal ion, usually an integer; It is the dissolution product of precious metals, that is, the ionic form of precious metals (such as the dissolution of gold will produce ),in is the oxidation state of the noble metal; The superoxide ion generated is a byproduct of the reaction of oxygen molecules with precious metals, usually generated by oxygen reduction.

[0053] During the reaction, the precious metal mineral reacts with the leaching agent to form metal ions, which dissolve into the solution. Oxygen participates in the reaction as an oxidant to form superoxide ions. This process is a typical redox reaction, in which the precious metal mineral is oxidized to release metal ions.

[0054] S3, introducing a catalyst to promote the dissolution reaction of precious metals; In step S2, by contacting the slurry with the leaching agent, the precious metal mineral begins to dissolve under suitable reaction temperature and reaction time conditions; in order to further increase the dissolution rate of the precious metal, especially under low temperature conditions, the key to step S3 is to introduce a catalyst; the catalyst can effectively reduce the activation energy of the precious metal dissolution reaction, thereby accelerating the reaction rate between the precious metal and the leaching agent and improving the efficiency of the precious metal dissolution; the introduction of the catalyst makes the entire dissolution reaction not only more efficient at low temperatures, but also reduces energy consumption and reduces the occurrence of side reactions.

[0055] The dissolution reaction of precious metal minerals usually follows a redox reaction mechanism; the role of the catalyst is to reduce the activation energy of the reaction ( ), thereby increasing the reaction rate; the reaction rate constant With temperature and activation energy The relationship between can be described by the Arrhenius equation: ; in: is the reaction rate constant; is the pre-exponential factor, which represents the collision frequency between reactants; It is the base of natural logarithms, also called Euler's number; is the activation energy of the reaction, in J / mol; is the gas constant, J / mol\cdotpK; is the reaction temperature in K.

[0056] Catalysts reduce the activation energy of a reaction ( ) to increase the reaction rate, thereby making the dissolution of precious metals more efficient at low temperatures; specifically, the catalyst provides an additional reaction pathway, changes the energy distribution of the reaction, and makes the reaction occur more smoothly.

[0057] In this embodiment, the selection of the catalyst is based on its promoting effect on the dissolution reaction of precious metal minerals; common catalysts include molybdenum, cobalt, copper and their alloys, etc. These transition metals can effectively reduce the activation energy of the dissolution reaction of precious metals; molybdenum and cobalt catalysts are often used in the dissolution reaction of gold and silver ores, while copper catalysts show better catalytic effects when processing some copper-containing ores.

[0058] Specifically, molybdenum catalysts are usually used to increase the dissolution rate of gold or silver ores, while cobalt and copper catalysts are usually used to process other precious metal ores. In experiments, the concentration of the catalyst is usually controlled in the range of 0.1% to 5% (w / w). Depending on the characteristics of different ores and the precious metal content, the concentration of the catalyst can be adjusted to ensure the optimal effect of the reaction.

[0059] During the dissolution of gold and silver ores, molybdenum, as a transition metal catalyst, can accelerate the reaction between precious metals and leaching agents through electron transfer. In the leaching of gold ores, molybdenum catalysts can provide a low-energy reaction pathway, allowing gold ore to dissolve faster at a lower temperature, and under the same conditions, molybdenum catalysts can significantly reduce the consumption of cyanide.

[0060] For example, in some experiments, when the molybdenum catalyst concentration was 0.2% (w / w), the dissolution rate of gold ore increased by 30% compared to the case without the addition of catalyst; this shows that molybdenum can significantly accelerate the reaction rate of gold ore dissolution and reduce the energy requirements of the reaction.

[0061] For copper-containing minerals, the use of copper catalysts exhibits a strong catalytic effect, especially in precious metal ores, copper catalysts can effectively improve the solubility of minerals; under the action of copper catalysts, the dissolution rate of silver ore is effectively improved; in some embodiments, when the concentration of copper catalyst is 0.5% (w / w), the dissolution rate of silver is increased by 25% compared to the case where no catalyst is used.

[0062] The introduction of catalysts can effectively increase the rate of noble metal dissolution reactions; catalysts can effectively reduce the activation energy of the reaction ( ), which enables the reaction to proceed efficiently at a lower temperature; specifically, the concentration of the catalyst and the reaction rate constant There is a positive correlation between them, that is, the higher the catalyst concentration, the faster the reaction rate, but too high a concentration may lead to a waste of solvent, so the catalyst concentration needs to be optimized.

[0063] In this embodiment, the optimization of the catalyst concentration can be adjusted through experimental data; by comparing the reaction rates at different concentrations, the optimal catalyst concentration can be found; generally speaking, when the catalyst concentration is too low, the improvement in the dissolution rate is not significant, while too high a concentration may lead to the saturation of the catalyst and the increase in the reaction rate tends to be stable.

[0064] In this embodiment, the amount of catalyst added is usually verified and optimized through experiments; in the experiment, the concentration of the catalyst usually starts from 0.1% (w / w) and gradually increases to 5% (w / w). The experimental results show that within this range, the catalyst concentration is linearly related to the dissolution rate of the precious metal; the specific amount of addition is adjusted according to the precious metal content of the ore and the dissolution rate requirements.

[0065] Gold ore leaching reaction: In the leaching reaction of gold ore, after adding 0.2% (w / w) molybdenum catalyst, the dissolution rate of gold ore increased by 30% compared with the dissolution rate without adding catalyst; this improvement shows that the molybdenum catalyst not only increases the reaction rate, but also reduces the time and energy required for the reaction; in addition, the consumption of cyanide is also significantly reduced during the dissolution of gold ore, indicating that the molybdenum catalyst optimizes the use of leaching agents while improving the reaction efficiency.

[0066] Silver ore leaching reaction: In the leaching reaction of silver ore, when 0.5% (w / w) copper catalyst was used, the dissolution rate of silver increased by 25% compared with the case without using a catalyst; this result shows that copper catalyst has a significant catalytic effect on the dissolution of silver ore, especially under low temperature conditions, copper catalyst can significantly increase the reaction rate and reduce the required reaction time.

[0067] S4, adjusting the reaction conditions by real-time monitoring of the progress of the dissolution reaction; In steps S2 and S3, the precious metal mineral contacts the leaching agent and begins to dissolve under the action of temperature, time and catalyst; at this time, the dissolution rate and the recovery efficiency of the precious metal will change with the progress of the reaction; in order to ensure that the dissolution reaction continues to proceed efficiently and avoid unnecessary energy consumption or the occurrence of side reactions, the present invention monitors the progress of the dissolution reaction in real time and adjusts the reaction conditions in real time to keep the reaction in the optimal state, thereby maximizing the dissolution rate and recovery rate of the precious metal; this step makes the control of the reaction process more precise and efficient, and can achieve maximum utilization of resources.

[0068] In this embodiment, the real-time monitoring system is used to track the dissolution reaction throughout the process; by collecting data in real time, the system can accurately understand the progress of the reaction and dynamically adjust the reaction conditions (such as temperature, leaching agent concentration, catalyst concentration, etc.) according to data feedback; this adjustment is automated, and the reaction system is optimized in real time through a feedback mechanism, thereby improving the dissolution efficiency of precious metals and reducing excessive consumption and the occurrence of side reactions.

[0069] The real-time monitoring system plays a vital role in the dissolution reaction; the main components of the system include: Temperature monitoring system: The temperature of the dissolution reaction has a direct impact on the reaction rate. When the reaction temperature is too low, the dissolution rate of precious metals is slow. When the temperature is too high, it may lead to excessive consumption of the leaching agent or the occurrence of side reactions. Therefore, a temperature sensor is installed in the reactor to monitor the temperature changes in real time and adjust the temperature through the temperature control device to ensure that the reaction is carried out within the optimal temperature range (usually 30°C to 50°C). Leaching agent concentration monitoring system: The concentration of the leaching agent directly affects the efficiency of precious metal dissolution. In practical applications, the concentration of the leaching agent needs to be adjusted according to the progress of the reaction. Too low a concentration may lead to incomplete dissolution of precious metals, while too high a concentration may waste the leaching agent and cause unnecessary side reactions. The concentration sensor monitors the concentration of the leaching agent in the reaction solution in real time and adjusts the supply of the leaching agent through a feedback mechanism. Precious metal ion concentration monitoring system: The concentration of precious metal ions is an important indicator for evaluating the progress of the reaction. Through conductivity sensors or other ion concentration measuring equipment, the system can detect changes in the concentration of precious metal ions in real time. When the concentration of precious metal ions increases, it means that the dissolution of the precious metal is in progress, and vice versa, it may mean that the dissolution reaction rate is slow. The system will adjust the reaction conditions according to the changes in ion concentration. Catalyst concentration monitoring system: Changes in catalyst concentration directly affect the dissolution reaction rate. During the reaction, by monitoring the catalyst concentration, it is possible to determine whether the reaction has reached the optimal rate. If the reaction is too slow, the catalyst concentration can be appropriately increased. If the reaction rate is too fast, the catalyst concentration may need to be appropriately reduced to prevent overreaction.

[0070] Based on the data obtained by the real-time monitoring system, the reaction conditions can be dynamically adjusted according to the progress of the reaction to ensure that the dissolution reaction is always in the optimal state.

[0071] Temperature regulation: Temperature control is crucial to the rate of dissolution reaction. When the temperature is too low, the dissolution rate is slow and the activation energy of the reaction is high. When the temperature is too high, it may cause the leaching agent to be consumed too quickly or side reactions to occur. Therefore, the temperature monitoring system can adjust the temperature in the reactor in real time to keep it within the optimal range of 30°C to 50°C. If the temperature is lower than the set value, the temperature control system will automatically start the heating device to increase the reaction temperature. If the temperature is too high, the cooling device will be used to reduce the reaction temperature to avoid overheating. Leaching agent concentration adjustment: The concentration of the leaching agent directly affects the dissolution efficiency of precious metals; the real-time monitoring system can detect changes in the concentration of the leaching agent to ensure that it is within the appropriate concentration range; when the system detects that the concentration is too low, the supply of the leaching agent will automatically increase; if the concentration is too high, the system will reduce the supply of the leaching agent by adjusting the equipment, thereby reducing unnecessary waste; Catalyst concentration adjustment: Adjustment of catalyst concentration will also affect the dissolution rate of precious metals; if the reaction rate is slow, the system will increase the catalyst concentration based on real-time monitoring data; if the reaction rate is too fast, side reactions may occur, and the system will reduce the catalyst concentration to ensure the stability of the reaction.

[0072] The dissolution reaction of precious metals is usually a redox reaction, and the reaction rate is closely related to temperature, leaching agent concentration and catalyst concentration. In order to accurately control the reaction process, real-time monitoring data is input into the kinetic model to calculate the reaction rate constant. The rate of noble metal dissolution can usually be described by the following rate equation: ; in: is the rate at which the concentration of noble metal ions changes with time; is the reaction rate constant; is the concentration of precious metal minerals; is the concentration of the leaching agent in the dissolution reaction.

[0073] Through this rate equation, the reaction rate can be updated according to real-time data and the reaction conditions can be adjusted as needed; the reaction rate constant It can be further expressed by the following Arrhenius equation: ; in: is the reaction rate constant; is the pre-exponential factor, which represents the collision frequency between reactants; It is the base of natural logarithms, also called Euler's number; is the activation energy of the reaction, in J / mol; is the gas constant, J / mol\cdotpK; is the reaction temperature in K.

[0074] According to this formula, the reaction rate constant The change of can be associated with the change of temperature, leaching agent concentration and catalyst concentration, so as to adjust the reaction conditions in real time to maximize the reaction efficiency.

[0075] In some embodiments, the real-time monitoring system can timely adjust the temperature, leaching agent concentration and catalyst concentration by analyzing the progress data of the dissolution reaction; for example, in the gold ore dissolution reaction, when the real-time monitoring data shows that the gold ore dissolution rate slows down, the system will automatically increase the temperature or increase the leaching agent concentration to ensure that the dissolution rate of the precious metal does not decrease.

[0076] In another embodiment, in the initial stage of the reaction of the silver ore, the dissolution rate of the precious metal is slow; at this time, after the monitoring system finds that the growth rate of the silver ion concentration has slowed down, it automatically adjusts the catalyst concentration and increases the temperature, thereby accelerating the reaction process and ultimately improving the silver recovery rate.

[0077] S5, extracting the dissolved precious metal ions; In the aforementioned steps S2 and S3, after the precious metal minerals undergo a dissolution reaction, the precious metals have been converted into metal ions in the solution; at this time, the goal of step S5 is to effectively extract these dissolved precious metal ions from the solution for subsequent purification and recovery; the extraction method usually adopts solvent extraction, precipitation, electrolysis or other chemical methods, which are selected according to factors such as the type of precious metal, the composition of the solution and the recovery efficiency; through these methods, the precious metal ions can be efficiently separated from the solution and the precious metal can be finally obtained.

[0078] In this embodiment, by selecting a suitable extraction method and controlling the reaction conditions, the precious metal ions are effectively extracted from the solution, and it is ensured that no loss of precious metals or introduction of impurities occurs during the extraction process.

[0079] Solvent extraction is widely used in the extraction process of precious metals, especially for separating and enriching precious metals from solutions. This method relies on the coordination between precious metal ions and organic solvents, and transfers precious metal ions from aqueous solutions to organic solvents through the principle of phase distribution. Commonly used solvents include organic acids, amides, alcohols or other chemical reagents with high affinity.

[0080] In this embodiment, a suitable organic solvent (such as dimethyl amide, trioctyl phosphine, or other organic solvents with high solubility) is selected to perform solvent extraction of precious metals; the specific steps include: Selecting an organic solvent: Selecting a suitable organic solvent based on the solubility properties of the noble metal; the solvent can react with the noble metal ions to transfer the noble metal ions from the solution to the organic solvent phase; Extraction process: After the noble metal ions react with the organic solvent, the metal ions are transferred from the aqueous solution to the organic phase through the liquid-liquid distribution principle; the extraction efficiency is affected by factors such as solvent concentration, pH value, and temperature, so these parameters need to be optimized in the experiment; Separation of precious metals: Through phase distribution technology, the dissolved precious metals are extracted into the organic solvent phase; the choice of solvent and the ion concentration in the solution will affect the extraction efficiency, so it is necessary to optimize the type, concentration and operating temperature of the extraction solvent; In some embodiments, solvent extraction is used in the recovery process of gold ore, using solvents such as dimethylformamide (DMF) to extract gold ions from the gold ore solution; by adjusting the concentration, pH value and temperature of the solvent, high-purity gold can be obtained.

[0081] The precipitation method is a method of converting precious metal ions into solid metal compounds by chemical reaction; in this method, by adding an appropriate precipitant, the precious metal ions react with the precipitant to form a metal compound that is insoluble in the solution; then, the metal compound is precipitated and separated from the solution.

[0082] In this embodiment, common precipitants include chlorides, fluorides, sulfides, hydroxides, etc.; for example, by adding hydrogen chloride (HCl) gas to the solution, it can react with silver ions in the solution to generate silver chloride (AgCl) precipitates.

[0083] The reaction equation is as follows: ; in: For silver ions; is chloride ion; It is silver chloride precipitate.

[0084] This method is suitable for the extraction of most precious metal minerals, especially when the metal ion concentration is high; through precipitation reaction, precious metal ions can be efficiently separated, and the precipitate can be separated by filtration or centrifugation.

[0085] Electrolysis is a technology that uses electric current to reduce precious metal ions to metals. It is suitable for recovering higher purity precious metals from solutions. Electrolysis can not only extract precious metals from solutions, but also further improve the purity of precious metals.

[0086] In this embodiment, precious metal ions (such as gold ions and silver ions) are reduced to metals by electrolysis and precipitated on the cathode of the electrolytic cell; the specific process is as follows: Configuration of the electrolytic cell: An anode and a cathode are provided in the electrolytic cell, a solution containing precious metal ions is added to the solution, and an electric current is passed through it.

[0087] Electrolysis reaction: Through the action of electric current, precious metal ions are reduced to metal and deposited on the cathode; the basic equation of electrolysis reaction is as follows: ; in: For noble metal ions (such as wait); For electronics; It is the deposition of precious metals (such as gold and silver) after reduction.

[0088] The electrolysis method can efficiently convert precious metal ions in the solution into metal deposits with high purity. In some embodiments, the electrolysis method is used to recover silver and gold from the solution, and the purity of the precipitated metal can reach more than 99% during the electrolysis process.

[0089] After the precious metal ions are extracted by solvent extraction, precipitation or electrolysis, the extract may contain other impurities or by-products. In order to ensure the high purity of the precious metals, further purification is usually required. Common purification methods include: Acid leaching: The precious metal precipitate is dissolved in an acid solution to separate impurities; this method is suitable for removing residual metal impurities in the ore.

[0090] Water washing: Use pure water to wash the extract to remove solvent or chemical reagent residues to improve the purity of precious metals.

[0091] Reduction Treatment: In some cases, the precious metal precipitate may need to be further purified by reduction reaction to achieve a higher purity of the metal.

[0092] In practical applications, solvent extraction and precipitation are often used in combination to optimize the recovery process of precious metals; for example, in the recovery of gold ore, cyanide is first used to dissolve the gold ore to obtain a gold solution, then solvent extraction is used to extract gold ions from the solution, and precipitation is used to separate gold from impurities; after these steps, high-purity gold can be obtained.

[0093] In the recovery of silver ore, hydrogen chloride gas is used to react with silver ions to generate silver chloride precipitate, and then impurities are removed by filtering and washing to obtain high-purity silver.

[0094] See also Figure 2 , a system for recovering and enriching precious metals in low-grade precious metal complex materials, comprising: Pretreatment module: The main function of this module is to conduct preliminary treatment of low-grade precious metal complex materials, remove unnecessary impurity minerals, and crush the ore to a particle size suitable for subsequent leaching reactions; through physical methods such as screening and grinding, the particle size of the ore is optimized to increase the exposure rate of precious metal minerals; this module can also be combined with chemical pretreatment methods, such as acid leaching or oxidation treatment, to further remove impurities that may affect the dissolution of precious metals; the pretreated ore enters the subsequent leaching reaction to obtain a slurry containing precious metals; Leaching module, which includes a leaching agent supply device, a temperature control device and a catalyst supply device, and is mainly used to promote the dissolution reaction of precious metal minerals under low temperature conditions; the leaching agent is accurately controlled by the supply device to ensure that its concentration is moderate and the reaction efficiency is maintained; the temperature control device ensures that the reaction temperature is kept in the optimal range to prevent excessively high or low temperatures from affecting the dissolution rate of precious metals; the catalyst supply device helps reduce the activation energy of the reaction and accelerate the dissolution process of precious metals by accurately controlling the amount of catalyst added; the reactor in this module can be adjusted according to different ore types, precious metal types and leaching agent concentrations to ensure efficient dissolution of precious metals; Real-time monitoring module: This module is responsible for monitoring the progress of the precious metal dissolution reaction and adjusting the reaction conditions according to real-time data; it obtains the state of the reaction liquid in real time through temperature sensors, leaching agent concentration sensors, catalyst concentration monitors and other equipment; it adjusts the reaction temperature, leaching agent concentration and catalyst concentration according to the reaction progress to ensure that the dissolution reaction is carried out under the best conditions; this module also performs data analysis, predicts the trend of the reaction, and feeds back information to the control system module for dynamic adjustment; Extraction module: The function of the extraction module is to extract the dissolved precious metal ions from the solution to ensure the efficient recovery of precious metals. Common extraction methods include solvent extraction, precipitation or electrolysis. In the solvent extraction process, precious metal ions react with selective solvents and are transferred to the organic phase for further separation and recovery. Precipitation converts precious metals into insoluble compounds by adding appropriate precipitants for easy separation. Electrolysis reduces precious metal ions to metals and deposits them through electrolysis. Choose the appropriate extraction method based on the type of precious metal and the composition of the solution. Control system module: The control system module integrates the operation of each sub-module and coordinates the work between them to ensure the smooth progress of the entire recovery process; the system can automatically adjust the operating status of each module according to the feedback information of the real-time monitoring module, such as the supply amount of leaching agent, adjustment of catalyst concentration, control of reaction temperature, etc., so as to ensure the recovery efficiency of precious metals; the control system module can also remotely monitor and dispatch the equipment, handle possible faults in time, and optimize various operating conditions to improve the automation and intelligence level of the system.

[0095] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for recovering and enriching precious metals in low-grade precious metal complex materials, characterized in that: The following steps are involved: S1. Pre-treating low-grade precious metal complex materials to obtain precious metal-containing ore pulp; S2, contacting the slurry with the leaching agent, and performing a dissolution reaction under reaction temperature and reaction time conditions; S3, introducing a catalyst to promote the dissolution reaction of precious metals; S4, adjusting the reaction conditions by real-time monitoring of the progress of the dissolution reaction; S5. extracting the dissolved precious metal ions.

2. A method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The catalyst is molybdenum, cobalt and copper, and the concentration of the catalyst is 0.1% to 5%.

3. A method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The leaching agent is cyanide or chloride, and the concentration of the leaching agent is 0.01M to 1M.

4. A method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: In the dissolution reaction, the dissolution rate of the noble metal follows the Arrhenius equation, the reaction rate constant varies with temperature, and the reaction activation energy is reduced by the introduction of a catalyst; The dissolution reaction rate follows the Arrhenius equation, and the reaction rate constant With temperature The relationship is: ； in: is the reaction rate constant; is the pre-exponential factor, which represents the collision frequency between reactants; It is the base of natural logarithms, also called Euler's number; is the activation energy of the reaction, in J / mol; is the gas constant, J / mol\cdotpK; is the reaction temperature in K.

5. The method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: Gibbs free energy change in the dissolution reaction The spontaneous dissolution conditions are met, where ; Gibbs free energy change It can be calculated by the following formula: ； in: is the Gibbs free energy change of the reaction; is the enthalpy change of the reaction; is temperature; is the entropy change of the reaction.

6. A method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The progress of the dissolution reaction is monitored in real time by a sensor, and the reaction conditions including temperature, leaching agent concentration and catalyst concentration are adjusted.

7. A method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The noble metal ions in the dissolution reaction are separated from the solution by solvent extraction.

8. The method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The precious metal complex material includes gold and silver, and the precious metal content thereof is lower than 5g / t.

9. The method for recovering and enriching precious metals in low-grade precious metal complex materials according to claim 1, characterized in that: The pretreatment includes screening, grinding and chemical treatment steps. Screening is used to remove larger particles of minerals. Grinding refines mineral particles to a particle size suitable for leaching. Chemical treatment uses an acid leaching method to remove impurity minerals that affect the dissolution reaction.

10. A system for recovering and enriching precious metals in low-grade precious metal complex materials, applied to a method for recovering and enriching precious metals in low-grade precious metal complex materials as claimed in any one of claims 1 to 9, characterized in that: include: Pretreatment module, used to process low-grade precious metal complex materials and obtain precious metal-containing slurry; A leaching module, including a leaching agent supply device, a temperature control device, and a catalyst supply device, for promoting the dissolution reaction of precious metals under low temperature conditions; Real-time monitoring module, used to monitor the progress of precious metal dissolution reaction, and adjust temperature, leaching agent concentration and catalyst concentration; An extraction module, used for extracting dissolved precious metal ions from the solution; The control system module coordinates the work of each module and adjusts the reaction conditions to ensure the recovery efficiency of precious metals.

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