A high-efficiency, low-toxic and environmentally friendly gold dissolving agent and its preparation method and application in precious metal production

Abstract

The present invention discloses a kind of high-efficiency, low-toxic and environmentally friendly gold-dissolving agent and its preparation method and application in precious metal production. The gold-dissolving agent is in parts by weight, and includes the following raw materials: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, and 3-5 parts of sintering agent. The present invention aims to provide a low-toxic and environmentally friendly agent for the precious metal production industry, which replaces sodium cyanide on the basis of not substantially changing the original production equipment process, and provides a feasible solution for the precious metal production industry. The production method of the product of the present invention is concise and clear, with a short process flow and low operating difficulty, which is conducive to rapid promotion and large-scale production. This not only reduces the skill requirements for production personnel, but also improves the stability and reliability of the production line, and provides a strong guarantee for the sustained and stable development of precious metal production enterprises.

Description

Technical Field

[0001] The invention belongs to the technical field of environmentally friendly gold dissolving agents, and specifically relates to a high-efficiency, low-toxic and environmentally friendly gold dissolving agent and a preparation method thereof and application thereof in precious metal production. Background Art

[0002] In the modern industrial field, the extraction of precious metals such as gold and silver has become a vital technical activity. The process is complex and delicate, involving unlocking the secrets of these precious metals from ores buried deep underground. This process first relies on efficient and targeted chemical agents that can penetrate the hard shell of the ore, dissolve and release the precious metals such as gold and silver hidden therein. These chemicals, such as sodium cyanide, thiourea, hypochlorite and perchlorate, each have unique chemical reaction characteristics and extraction efficiency, but all face severe tests of environmental friendliness and safety.

[0003] Among them, sodium cyanide, as a "veteran" in the gold extraction process, has long been the leading gold extraction agent due to its high efficiency and cost-effectiveness, and is widely used in gold mining and refining around the world. However, behind the glamour lies a hidden worry that cannot be ignored - the extreme toxicity of sodium cyanide. If this substance is not handled with care during operation, it may cause devastating damage to the ecological environment, affect water safety, threaten biodiversity, and even pose a long-term hazard to human health. Therefore, in today's era of emphasizing safety, greenness, and sustainable development, the continued use of sodium cyanide gold extraction technology has been questioned and challenged unprecedentedly.

[0004] In response to this dilemma, governments around the world have introduced stringent regulations to impose strict environmental supervision on companies that use sodium cyanide to produce precious metals, and to levy high pollution treatment fees. Although the original intention of this measure was to protect the environment and public health, it has undoubtedly brought a heavy economic burden to the precious metal production industry. Many companies are therefore caught in a dilemma: continuing to use traditional processes means bearing high environmental costs and potential legal risks; while turning to new technologies may face a series of challenges such as immature technology, low leaching efficiency, and rising production costs.

[0005] Chinese patent document (patent number: ZL201010589648.9) discloses a low-toxic and environmentally friendly gold and silver beneficiation additive and its preparation method and application. Its main raw materials include sodium hydroxide, sodium carbonate, urea, and ferroxanthate. The preparation method is to heat sodium hydroxide, sodium bicarbonate, urea and ferroxanthate to 600-1000°C, and keep the materials warm for 1-2 hours after the materials reach a molten state, and then directly cool to room temperature, demold, and obtain a block of gold and silver beneficiation additive. The products of this invention can be widely used in the production of precious metal mines, such as soaking and heap leaching of oxidized gold ore, oxidized silver ore, and oxidized copper ore. It can also be used in industrial production industries such as electroplating to replace highly toxic sodium cyanide drugs, but there are problems such as long gold extraction time and low recovery rate, which cannot meet the application requirements.

[0006] One of the biggest challenges facing companies during the transformation journey is the stability and efficiency of new agent alternatives. Although new agents can theoretically reduce environmental pollution, their performance in actual applications is often difficult to meet theoretical expectations. Indicator fluctuations, low efficiency, and even complete failures in the leaching process often occur, which not only seriously affects the recovery rate of precious metals such as gold and silver, but also increases the operating costs and uncertainty of the company. Therefore, how to improve the extraction efficiency and stability of new agents while ensuring environmental friendliness has become a key issue that needs to be urgently addressed in the precious metal production industry.

[0007] Faced with these challenges, the industry is actively exploring innovative paths, including but not limited to developing more environmentally friendly and efficient gold dissolving agents, optimizing production processes, strengthening waste treatment and resource recycling, etc. At the same time, strengthening international cooperation and exchanges, sharing successful experiences and technological achievements, is also an important way to promote the transformation of the precious metal production industry towards a green and sustainable direction. Summary of the invention

[0008] The present invention provides a high-efficiency, low-toxic and environmentally friendly gold-dissolving agent and a preparation method thereof and application in precious metal production, aiming to provide a low-toxic and environmentally friendly agent for the precious metal production industry, and to replace sodium cyanide without substantially changing the original production equipment process, thereby providing a feasible solution for the precious metal production industry.

[0009] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0010] A highly efficient, low-toxic and environment-friendly gold dissolving agent comprises the following raw materials in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide and 3-5 parts of sintering agent.

[0011] Preferably, the high-efficiency, low-toxic and environmentally friendly gold-dissolving agent is characterized in that it comprises the following raw materials in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, and 4 parts of sintering agent.

[0012] Preferably, the raw materials for preparing the sintering agent include palladium iron and platinum nickel.

[0013] The present invention also provides a method for preparing a highly efficient, low-toxic and environmentally friendly gold dissolving agent, comprising the following steps:

[0014] (1) Weigh the raw materials according to the proportion: urea, sodium oxide, calcium oxide, and sintering agent;

[0015] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature, removing the foam, and calcining to obtain a material;

[0016] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting under the conditions of controlling microwave power, temperature and speed, then filtering and cooling to room temperature to obtain a crude product;

[0017] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving agent product.

[0018] Preferably, in step (2), the temperature is controlled at 150-300° C. and the calcination time is 0.5-3 h.

[0019] Preferably, the microwave power in step (3) is 100-300W.

[0020] Preferably, the temperature in step (3) is 900-1100°C.

[0021] Preferably, the rotation speed in step (3) is 60-80 r / min.

[0022] Preferably, the reaction time in step (3) is 4-6 h.

[0023] The present invention also provides an application of a high-efficiency, low-toxic and environmentally friendly gold-dissolving agent in the production of precious metals, which is applied to the extraction of gold and silver from gold- and silver-containing ores; the extraction of gold and silver from gold- and silver-containing smelting waste slag or waste materials; and the extraction of platinum, palladium, indium and the like from ores containing platinum, palladium, indium and the like.

[0024] Compared with the prior art, the innovative method of the present invention has shown unprecedented advantages. Its far-reaching impact is not only reflected in the dual improvement of environmental protection and safety, but also in promoting the green transformation and efficiency revolution of the precious metal extraction industry, which is specifically reflected in the following aspects:

[0025] (1) Toxicity is significantly reduced, a model of safety and environmental protection

[0026] Compared with the traditional highly toxic chemical sodium cyanide, the toxicity of isocyanato monoazoxide is significantly reduced. This revolutionary breakthrough stems from its unique molecular structure. Its three isocyanato side chains are closely connected in the form of stable covalent bonds. This bonding method effectively reduces the overall toxicity of the molecule, which is in sharp contrast to the instability of the cyanide ion bond in sodium cyanide. Therefore, in application, isocyanato monoazoxide not only ensures the safety of operators, but also greatly reduces the potential threat to the environment, truly realizing the concept of "green chemistry" and becoming a highlight in the field of precious metal extraction.

[0027] (2) Wide applicability, leading a new trend in precious metal extraction

[0028] The application scope of the present invention is extremely wide, covering the direct extraction of gold and silver ores, the recycling of precious metals in smelting slag and waste materials, and even the efficient separation of rare metal ores containing platinum, palladium, indium, etc. In industrial fields such as electroplating, it is an ideal substitute for sodium cyanide. With its significant advantages such as stable drug properties, environmental friendliness, and high cost-effectiveness, it has become a key force in promoting the green development of the industry. This innovation not only responds to the country's call for building an environmentally friendly society, but also indicates that the global precious metal production industry will usher in a profound change.

[0029] (3) Environmentally friendly, full-chain optimization

[0030] From the source of mineral processing to terminal processing, the present invention optimizes the environmental pollution problems existing in traditional methods. Whether in transportation, storage or use, it achieves low impact on the environment, ensures the safety of people and animals, and provides solid technical support for environmentally friendly gold extraction. This improvement not only reduces the risk of environmental pollution, but also improves the overall economic benefits by reducing the initial costs, demonstrating the great potential of technological innovation in promoting sustainable development.

[0031] (4) Low toxicity, environmental protection, and excellent safety performance

[0032] The invention uses more than 10 grams of the product to soak food and feed it to large mammals such as dogs, pigs, sheep, cattle, and horses for drinking without causing death; small animals such as frogs and grasshoppers falling into the lean liquid pool of the heap leaching are also not fatal. This fully proves the low toxicity and high safety of the product of the invention, providing a strong safety guarantee for practical application.

[0033] (5) Convenient transportation, cost-effective win-win

[0034] Since the product of the present invention is not flammable, explosive, corrosive, infectious or radioactive, its transportation process is greatly simplified. Whether it is road, rail, sea or air transportation, it can be carried out smoothly, effectively reducing transportation costs and risks, and laying a solid foundation for the wide promotion of products and rapid response to market demand.

[0035] (6) Efficient response and reduced costs

[0036] In the process of reacting with gold-containing ore, the gold dissolving agent of the present invention exhibits amazing speed and thoroughness, which not only improves production efficiency, but also significantly reduces production costs by reducing energy consumption and material consumption. This high-efficiency characteristic is of great significance for enhancing the dominant position of precious metal production enterprises in market competition.

[0037] (7) Simplified process and convenient operation

[0038] The production method of the product of the present invention is concise and clear, with a short process flow and low operating difficulty, which is conducive to rapid promotion and large-scale production. This not only reduces the skill requirements for production personnel, but also improves the stability and reliability of the production line, providing a strong guarantee for the sustainable and stable development of precious metal production enterprises.

[0039] (8) Raw materials are easily available and economic benefits are significant

[0040] The raw materials for the production of the product of the present invention are widely available and inexpensive, which creates favorable conditions for reducing production costs and improving economic benefits. At the same time, due to its significant environmental protection and high efficiency, the product of the present invention has strong competitiveness in the market, can bring good social and economic benefits to precious metal production enterprises, and achieve a win-win situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a flow chart of a method for preparing a highly efficient, low-toxic and environmentally friendly gold dissolving agent.

[0042] Figure 2 The present invention is a second flow chart of the method for preparing the high-efficiency, low-toxic and environmentally friendly gold-dissolving agent. DETAILED DESCRIPTION

[0043] In order to facilitate a better understanding of the present invention, the following examples are used to illustrate the present invention. These examples belong to the protection scope of the present invention, but do not limit the protection scope of the present invention.

[0044] In an embodiment of the present invention, a high-efficiency, low-toxic and environmentally friendly gold-dissolving agent includes the following raw materials in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, and 3-5 parts of sintering agent.

[0045] See Figure 1 The preparation method of an efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0046] (1) Weigh the following raw materials in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, and 3-5 parts of sintering agent;

[0047] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 150-300° C., removing the foam, and calcining for 0.5-3 h to obtain a material;

[0048] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 4-6 hours at a microwave power of 100-300 W, a temperature of 900-1100° C., and a rotation speed of 60-80 r / min, then filtering, and cooling to room temperature to obtain a crude product;

[0049] (4) The crude product obtained in step (3) is placed in a crusher for crushing, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold-dissolving agent with a particle size of 8.6-43.8 mm.

[0050] The technical principle of the invention for preparing the high-efficiency, low-toxic and environmentally friendly gold dissolving agent:

[0051] Urea (30-50 parts) undergoes a polycondensation reaction at a certain temperature. Under the catalytic action of a sintering agent (3-5 parts), the polycondensation product further undergoes structural reformation to generate isocyano monoazoxide. The isocyano monoazoxide then reacts with calcium oxide (10-15 parts) and sodium oxide (20-30 parts) to generate calcium and sodium salts of isocyano monoazoxide.

[0052] In aqueous solution, under the action of oxidants, precious metal elements such as Au can be oxidized into Au+ ions, and the isocyanate in isocyanatomonoazoxide can undergo complexation reaction with Au+ ions, so that the solubility equilibrium of precious metal elements such as gold in water can continuously move to the right, thereby achieving the purpose of dissolving and extracting gold or precious metals.

[0053] Accurately controlling the amount of raw materials is the core element to ensure the performance stability of the high-efficiency, low-toxic and environmentally friendly gold dissolving agent of the present invention. Whether the raw materials are excessive or insufficient, it may cause the attenuation of gold dissolving efficiency or induce the formation of harmful by-products. In addition, the fine adjustment of process parameters, including the precise setting of calcination temperature, the reasonable configuration of microwave power and the optimization of reaction time, is of great significance for improving reaction efficiency, reducing energy consumption and ensuring the excellence of product quality.

[0054] In this process, the strict order of each step and the necessity of parameter optimization are fully demonstrated, which together weave into a highly precise and controllable reaction network. In this system, even the smallest adjustment may have a profound impact on the performance of the final product, highlighting the ultimate pursuit of precision and meticulousness in the field of fine chemicals.

[0055] In addition, on the basis of the original formula, other components are added to improve the performance, such as a high-efficiency, low-toxic and environmentally friendly gold-dissolving agent, which includes the following raw materials in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, 3-5 parts of sintering agent, 5-8 parts of potassium tripolyphosphate, 3-6 parts of ammonium peroxydisulfate, 12-18 parts of thiourea, and 1-2 parts of dioctyl sodium sulfosuccinate.

[0056] See Figure 2 The preparation method of an efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0057] (1) Weigh the following raw materials in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, 3-5 parts of sintering agent, 5-8 parts of potassium tripolyphosphate, 3-6 parts of ammonium peroxodisulfate, 12-18 parts of thiourea, and 1-2 parts of dioctyl sodium sulfosuccinate;

[0058] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 800-1000° C., removing the foam, and calcining for 5-8 hours to obtain a material;

[0059] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 4-6 hours at a microwave power of 100-300 W, a temperature of 900-1100° C., and a rotation speed of 60-80 r / min, then filtering, and cooling to room temperature to obtain a crude product;

[0060] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain Agent A.

[0061] (5) Mix the reagent A obtained in step (4) with potassium tripolyphosphate, ammonium peroxodisulfate, thiourea, and dioctyl sodium sulfosuccinate and put them into a crusher for crushing, and then pass through a 60-80 mesh sieve to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving reagent product.

[0062] The technical principle of the invention for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent with added components:

[0063] When deeply exploring the high-efficiency, low-toxic and environmentally friendly gold-dissolving agent with increased components, the present invention carefully analyzes the specific role of each component and how these components work ingeniously together to create remarkable technical results.

[0064] Urea (30-50 parts) undergoes a polycondensation reaction at a certain temperature. Under the catalytic action of a sintering agent (3-5 parts), the polycondensation product further undergoes structural reformation to generate isocyano monoazoxide. The isocyano monoazoxide then reacts with calcium oxide (10-15 parts) and sodium oxide (20-30 parts) to generate calcium and sodium salts of isocyano monoazoxide.

[0065] In aqueous solution, under the action of oxidants, precious metal elements such as Au can be oxidized into Au+ ions, and the isocyanate in isocyanatomonoazoxide can undergo complexation reaction with Au+ ions, so that the solubility equilibrium of precious metal elements such as gold in water can continuously move to the right, thereby achieving the purpose of dissolving and extracting gold or precious metals.

[0066] Potassium tripolyphosphate (5-8 parts): As a chelating agent, potassium tripolyphosphate can effectively complex metal ions and prevent them from precipitating in aqueous solution, thereby improving the completeness and stability of gold dissolution. At the same time, it also enhances the antioxidant properties of the agent and prolongs the service life of the agent.

[0067] Ammonium peroxodisulfate (3-6 parts): As a strong oxidant, ammonium peroxodisulfate provides the necessary oxidizing ability in the reaction, accelerates the oxidation reaction on the metal surface, promotes the transfer of metal ions into the solution, and significantly increases the gold dissolution rate.

[0068] Thiourea (12-18 parts): Thiourea, as a ligand, can form a stable metal complex, further enhancing the ability of the agent to capture metal ions. Its unique thio group can also inhibit the generation of harmful byproducts to a certain extent, maintaining the environmental friendliness of the agent.

[0069] Dioctyl sodium sulfosuccinate (1-2 parts): As a surfactant, dioctyl sodium sulfosuccinate effectively reduces the surface tension of the agent, enhances the wettability and permeability of the agent to the metal surface, and makes the gold dissolution process more uniform and efficient.

[0070] Synergy and technical effects:

[0071] These raw materials work together through complex chemical reactions and physical effects during the preparation process, forming a unique gold dissolution mechanism. The calcination process of urea and sintering agent not only removes impurities, but also enhances the activity of the raw materials; the calcium oxide and sodium oxide added subsequently react rapidly under microwave heating to generate calcium and sodium salts of isocyanomonoazoxide, which is agent A; potassium tripolyphosphate, ammonium peroxodisulfate, thiourea and dioctyl sodium sulfosuccinate can synergistically improve the gold dissolution efficiency through chelation, oxidation, coordination and surface activation respectively.

[0072] Importance of raw material dosage and process parameter optimization:

[0073] Precise control of the amount of raw materials is the key to ensuring the stability of the performance of the agent. Too much or too little raw materials may lead to a decrease in gold dissolution efficiency or the production of harmful byproducts. At the same time, the optimization of process parameters, such as calcination temperature, microwave power, reaction time, etc., is crucial to improving reaction efficiency, reducing energy consumption and ensuring product quality. The non-interchangeability of each step and the necessity of parameter optimization are reflected in the fact that they jointly construct a finely controlled reaction system, and any slight change may affect the performance of the final product.

[0074] In summary, the preparation process of the high-efficiency, low-toxic and environmentally friendly gold-dissolving agent of the present invention achieves efficient dissolution of metals through carefully designed raw material ratios and strict process control, while maintaining good environmental performance, demonstrating its great potential in the fields of precious metal recovery and metal processing.

[0075] The preparation method of the sintering agent used in the above two formulations comprises the following steps:

[0076] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0077] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0078] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0079] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0080] The preparation technology principle of the sintering agent of the present invention:

[0081] The preparation method of sintering agent, as a precise and complex process, not only involves the precise proportion of multiple key raw materials, but also relies on the fine control of process parameters such as temperature and time to ensure that the final product - sintering agent (i.e. catalyst) can play an excellent catalytic role. The following is an in-depth description of each link of the preparation process, aiming to reveal the scientific principles and process wisdom behind it.

[0082] Step 1: Preheating of palladium iron

[0083] First, add 22 parts of palladium iron as the starting material in units accurate to parts by weight. Due to its unique electronic structure, palladium iron exhibits excellent performance in the field of catalysis and is an important basis for the activity of sintering agents. Using natural gas as a heat source, the system temperature is gradually increased to 950°C. This temperature setting is designed to activate the active sites of palladium iron, while removing impurities and moisture, and providing a clean and activated surface for subsequent chemical reactions. The 10-hour heat preservation process ensures uniform heating and full conversion of palladium iron particles. The obtained material a is not only a change in physical state, but also a leap in chemical activity.

[0084] Step 2: Synergistic addition of platinum nickel and high titanium stone

[0085] Next, 8.2 parts of platinum-nickel alloy and 5.3 parts of high-titanium stone were precisely added to material a. Platinum-nickel alloy is known for its high catalytic activity and stability, which can further enhance the catalytic efficiency of the sintering agent; and high-titanium stone, with its unique crystal structure and chemical properties, provides additional structural support and possible active centers for the sintering agent. Natural air drying for 9 hours is not only to remove moisture that may be introduced during the mixing process, but also to promote the initial bonding and reaction between the components. Subsequently, it was heated to 1060°C in an electric furnace. This high-temperature treatment not only deepened the interaction between palladium iron, platinum-nickel and high-titanium stone, but also promoted the formation of solid solutions or complexes that may be formed between them, greatly improving the catalytic performance of the sintering agent. Keeping warm for 20 hours ensured the full progress of this complex reaction process, and the obtained material b reached new heights in structure and performance.

[0086] Step 3: Adding fluorite and high temperature refining

[0087] After material b is naturally cooled for 8 hours, it enters the processing flow again. At this time, 20 parts of fluorite are added. As a common mineralizer, fluorite not only adjusts the solubility and fluidity of the system, but also reacts with the original components at high temperature to form a new active phase or pore structure, further improving the catalytic activity and selectivity of the sintering agent. It is heated to 1150°C again. This higher temperature setting is designed to promote deeper chemical reactions and phase changes. It is kept warm for 18 hours to ensure the thorough completion of all reactions and the optimization of the internal structure of the sintering agent. In this step, the synergy between the components has reached an unprecedented level, forming a unique microstructure and active center, laying a solid foundation for the efficient catalysis of the sintering agent.

[0088] Step 4: Grinding into powder and final product

[0089] Finally, the material C cooled for 6 hours is finely ground until a uniform powdered sintering agent is formed. The grinding process not only improves the dispersibility of the sintering agent, but also increases its specific surface area, thereby improving the efficiency of the catalytic reaction. The prepared sintering agent, with its optimized composition, unique structure and efficient catalytic performance, lays a foundation for the preparation of efficient, low-toxic and environmentally friendly gold dissolving agents of the present invention.

[0090] Importance of raw material dosage and process parameter optimization:

[0091] During the entire preparation process, it is crucial to strictly control the amount of each raw material. Excess or insufficient amount may destroy the balance between components and affect the final performance of the sintering agent. At the same time, the optimization of process parameters, such as precise control of heating temperature and holding time, is directly related to the thoroughness of the chemical reaction and the quality stability of the sintering agent. Fine-tuning these parameters can often bring unexpected technical effects, such as improving catalytic activity and extending service life.

[0092] Irreplaceability and optimization of process steps:

[0093] Each step has its specific purpose and necessity, and cannot be arbitrarily replaced or omitted. For example, the preheating treatment in the first step provides the necessary active basis for the subsequent reaction; the synergistic addition in the second step builds the core structure of the sintering agent; the high-temperature refining in the third step further optimizes and consolidates this structure; and the grinding in the fourth step converts the optimized structure into a practical catalyst form. The optimization of each step is an improvement in the overall process performance, and any negligence in any step may lead to a decrease in the performance of the final product.

[0094] In summary, the preparation method of the sintering agent of the present invention is a highly integrated technology, which integrates the knowledge and wisdom of multiple disciplines such as materials science and chemical engineering. Through fine raw material ratios, rigorous process control and innovative reaction mechanisms, it achieves a leap in the catalytic performance of the sintering agent, effectively reduces the temperature of the catalytic reaction, reduces the catalytic time, and saves energy.

[0095] In order to make the disclosure of the present invention more complete, it is described below through more specific embodiments.

[0096] Example 1

[0097] A high-efficiency, low-toxic and environmentally friendly gold-dissolving agent is characterized in that it includes the following raw materials in parts by weight: 31 parts of urea, 23 parts of sodium oxide, 10 parts of calcium oxide, and 3 parts of sintering agent.

[0098] The preparation method of the sintering agent comprises the following steps:

[0099] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0100] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0101] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0102] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0103] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0104] (1) Weigh the following raw materials in parts by weight: 31 parts of urea, 23 parts of sodium oxide, 10 parts of calcium oxide, and 3 parts of sintering agent;

[0105] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 250° C., removing the foam, and calcining for 3 hours to obtain a material;

[0106] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 6 hours at a microwave power of 100 W, a temperature of 900° C., and a rotation speed of 60 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0107] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving agent product.

[0108] Example 2

[0109] A high-efficiency, low-toxic and environmentally friendly gold-dissolving agent is characterized in that it comprises the following raw materials in parts by weight: 48 parts of urea, 29 parts of sodium oxide, 14 parts of calcium oxide, and 4.9 parts of sintering agent.

[0110] The preparation method of the sintering agent comprises the following steps:

[0111] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0112] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0113] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0114] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0115] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0116] (1) Weigh the following raw materials in parts by weight: 48 parts of urea, 29 parts of sodium oxide, 14 parts of calcium oxide, and 4.9 parts of sintering agent;

[0117] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 150° C., removing the foam, and calcining for 1 hour to obtain a material;

[0118] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 4 hours at a microwave power of 300 W, a temperature of 1100° C., and a rotation speed of 80 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0119] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving agent product.

[0120] Example 3

[0121] A high-efficiency, low-toxic and environmentally friendly gold-dissolving agent is characterized in that it includes the following raw materials in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, and 4 parts of sintering agent.

[0122] The preparation method of the sintering agent comprises the following steps:

[0123] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0124] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0125] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0126] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0127] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0128] (1) Weigh the following raw materials in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, and 4 parts of sintering agent;

[0129] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 300° C., removing the foam, and calcining for 3 hours to obtain a material;

[0130] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 5.2 hours at a microwave power of 200 W, a temperature of 1000° C., and a rotation speed of 70 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0131] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving agent product.

[0132] Example 4

[0133] A highly efficient, low-toxic and environment-friendly gold dissolving agent comprises the following raw materials in parts by weight: 31 parts of urea, 23 parts of sodium oxide, 10 parts of calcium oxide, 3 parts of sintering agent, 5 parts of potassium tripolyphosphate, 3.2 parts of ammonium peroxodisulfate, 13 parts of thiourea and 1.2 parts of dioctyl sodium sulfosuccinate.

[0134] The preparation method of the sintering agent comprises the following steps:

[0135] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0136] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0137] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0138] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0139] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0140] (1) Weigh the following raw materials in parts by weight: 31 parts of urea, 23 parts of sodium oxide, 10 parts of calcium oxide, 3 parts of sintering agent, 5 parts of potassium tripolyphosphate, 3.2 parts of ammonium peroxodisulfate, 13 parts of thiourea, and 1.2 parts of dioctyl sodium sulfosuccinate;

[0141] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 150° C., removing the foam, and calcining for 3 hours to obtain a material;

[0142] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 6 hours at a microwave power of 100 W, a temperature of 900° C., and a rotation speed of 60 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0143] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain Agent A.

[0144] (5) Mix the reagent A obtained in step (4) with potassium tripolyphosphate, ammonium peroxodisulfate, thiourea, and dioctyl sodium sulfosuccinate and put them into a crusher for crushing, and then pass through a 60-mesh sieve to obtain a high-efficiency, low-toxic, and environmentally friendly gold-dissolving reagent product.

[0145] Example 5

[0146] A highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following raw materials in parts by weight: 48 parts of urea, 29 parts of sodium oxide, 14 parts of calcium oxide, 4.9 parts of sintering agent, 7 parts of potassium tripolyphosphate, 5.8 parts of ammonium peroxydisulfate, 16.9 parts of thiourea and 2 parts of dioctyl sodium sulfosuccinate.

[0147] The preparation method of the sintering agent comprises the following steps:

[0148] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0149] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0150] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0151] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0152] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0153] (1) Weigh the following raw materials in parts by weight: 48 parts of urea, 29 parts of sodium oxide, 14 parts of calcium oxide, 4.9 parts of sintering agent, 7 parts of potassium tripolyphosphate, 5.8 parts of ammonium peroxodisulfate, 16.9 parts of thiourea, and 2 parts of dioctyl sodium sulfosuccinate;

[0154] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 200° C., removing the foam, and calcining for 3 hours to obtain a material;

[0155] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 4 hours at a microwave power of 300 W, a temperature of 1100° C., and a rotation speed of 80 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0156] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain Agent A.

[0157] (5) Mix the reagent A obtained in step (4) with potassium tripolyphosphate, ammonium peroxodisulfate, thiourea, and dioctyl sodium sulfosuccinate and put them into a crusher for crushing, and then pass through a 70-mesh sieve to obtain a high-efficiency, low-toxic, and environmentally friendly gold-dissolving reagent product.

[0158] Example 6

[0159] A highly efficient, low-toxic and environment-friendly gold dissolving agent comprises the following raw materials in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, 4 parts of sintering agent, 6 parts of potassium tripolyphosphate, 5 parts of ammonium peroxodisulfate, 14 parts of thiourea and 1.6 parts of dioctyl sodium sulfosuccinate.

[0160] The preparation method of the sintering agent comprises the following steps:

[0161] The first step is to add 22 parts of palladium iron by weight, heat it with natural gas to 950°C, keep it warm for 10 hours and then take it out to obtain material a;

[0162] In the second step, 8.2 parts of platinum nickel and 5.3 parts of high titanium stone were added to the material a obtained in the first step, and after natural air drying for 9 hours, the material was added to an electric furnace and heated to 1060° C. and kept warm for 20 hours to obtain material b;

[0163] The third step is to cool the material b obtained in the second step naturally for 8 hours, then open the electric furnace, add 20 parts of fluorite, and heat it to 1150°C, keep it warm for 18 hours, and obtain material c;

[0164] In the fourth step, the material c obtained in the third step is cooled for 6 hours and then ground into powder to obtain a sintering agent.

[0165] The method for preparing the highly efficient, low-toxic and environmentally friendly gold dissolving agent comprises the following steps:

[0166] (1) Weigh the following raw materials in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, 4 parts of sintering agent, 6 parts of potassium tripolyphosphate, 5 parts of ammonium peroxodisulfate, 14 parts of thiourea, and 1.6 parts of dioctyl sodium sulfosuccinate;

[0167] (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature to 300° C., removing the foam, and calcining for 0.5 h to obtain a material;

[0168] (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting for 5.2 hours at a microwave power of 200 W, a temperature of 1000° C., and a rotation speed of 70 r / min, then filtering and cooling to room temperature to obtain a crude product;

[0169] (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain Agent A.

[0170] (5) Mix the reagent A obtained in step (4) with potassium tripolyphosphate, ammonium peroxodisulfate, thiourea, and dioctyl sodium sulfosuccinate and put them into a crusher for crushing, and then pass through an 80-mesh sieve to obtain a high-efficiency, low-toxic, and environmentally friendly gold-dissolving reagent product.

[0171] Application Example 1

[0172] 10 tons of oxidized gold ore containing 3.612 g / t of gold was weighed, crushed, added with water and lime, and then stirred at 200 rpm, and then 480 g of the gold dissolving agent prepared in Example 1 was added and soaked for 12 hours, and then the leached liquid was adsorbed with activated carbon, and gold was obtained after roasting and refining.

[0173] Application Example 2

[0174] 10 tons of silver oxide ore containing 48.872 g / t of silver was weighed, crushed, added with water and lime, and then stirred at 200 rpm, and then 480 g of the gold dissolving agent prepared in Example 2 was added and soaked for 8 hours, and then recovered by conventional methods to obtain metallic silver.

[0175] Application Example 3

[0176] Weigh 10 tons of ore powder containing 2.946 g / ton of gold and 28.569 g / ton of silver, add water and lime, then stir at 200 rpm, add 480 g of the gold-dissolving agent prepared in Example 3, soak for 12 hours, and then recover by conventional methods to obtain metallic gold and metallic silver.

[0177] Application Example 4

[0178] 10 tons of oxidized gold ore containing 3.612 g / t of gold was weighed, crushed, added with water and lime, and then stirred at 200 rpm, and then 480 g of the gold dissolving agent prepared in Example 4 was added and soaked for 12 hours, and then the leached liquid was adsorbed with activated carbon, and gold was obtained after roasting and refining.

[0179] Application Example 5

[0180] 10 tons of silver oxide ore containing 48.872 g / t of silver was weighed, crushed, added with water and lime, and then stirred at 200 rpm, and then 480 g of the gold dissolving agent prepared in Example 5 was added and soaked for 8 hours, and then recovered by conventional methods to obtain metallic silver.

[0181] Application Example 6

[0182] Weigh 10 tons of ore powder containing 2.946 g / ton of gold and 28.569 g / ton of silver, add water and lime, then stir at 200 rpm, add 480 g of the gold-dissolving agent prepared in Example 6, soak for 12 hours, and then recover by conventional methods to obtain metallic gold and metallic silver.

[0183] Comparative Example 1

[0184] The method of Example 1 in the Chinese patent document “Pollution-free mineral processing additive and its preparation method and application (patent number: ZL201010589648.9)” was used to extract metallic gold.

[0185] Comparative Example 2

[0186] The metallic silver was extracted by using the method of Example 2 in the Chinese patent document “Pollution-free mineral processing additive and its preparation method and application (patent number: ZL201010589648.9)”.

[0187] Comparative Example 3

[0188] The method of Example 3 in the Chinese patent document "Pollution-free mineral processing additive and its preparation method and application (patent number: ZL201010589648.9)" was used to extract metallic gold and metallic silver.

[0189]

[0190]

[0191] It can be seen from the above table that: (1) the gold and silver leaching rates obtained by using the two gold dissolving agents of the present invention are significantly higher than the gold and silver leaching rates obtained by the gold dissolving agents prepared by the prior art, and the gold dissolving agents of the present invention have a faster gold extraction speed, which shows that the technology of the present invention has significant progress compared with the prior art.

[0192] (2) The gold and silver leaching rate data obtained by using the gold dissolving agent of Example 4-6 and the gold and silver leaching rate data obtained by using the gold dissolving agent of Example 4-6 show that after adding potassium tripolyphosphate, ammonium peroxydisulfate, thiourea and dioctyl sodium sulfosuccinate on the basis of the original formula, the gold and silver leaching rates are significantly improved. This is because potassium tripolyphosphate, ammonium peroxydisulfate, thiourea and dioctyl sodium sulfosuccinate respectively improve the gold dissolving efficiency and the gold and silver leaching rates through the synergistic effects of chelation, oxidation, coordination and surface activation.

[0193] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A highly efficient, low-toxic and environmentally friendly gold dissolving agent, characterized in that: The raw materials are as follows, in parts by weight: 30-50 parts of urea, 20-30 parts of sodium oxide, 10-15 parts of calcium oxide, and 3-5 parts of sintering agent.

2. The high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1 is characterized in that: The raw materials are as follows, in parts by weight: 42 parts of urea, 27 parts of sodium oxide, 12 parts of calcium oxide, and 4 parts of sintering agent.

3. The high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1 or 2, characterized in that: The raw materials for preparing the sintering agent include palladium iron and platinum nickel.

4. A method for preparing a highly efficient, low-toxic and environmentally friendly gold dissolving agent according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Weigh the raw materials according to the proportion: urea, sodium oxide, calcium oxide, and sintering agent; (2) putting the urea and sintering agent weighed in step (1) into a muffle furnace, controlling the temperature, removing the foam, and calcining to obtain a material; (3) adding calcium oxide and sodium oxide to the material obtained in step (2), reacting under the conditions of controlling microwave power, temperature and speed, then filtering and cooling to room temperature to obtain a crude product; (4) The crude product obtained in step (3) is placed in a crusher for pulverization, and then sieved to obtain a high-efficiency, low-toxic and environmentally friendly gold dissolving agent product.

5. The method for preparing the high-efficiency, low-toxic and environmentally friendly gold-dissolving agent according to claim 1, characterized in that: In step (2), the temperature is controlled at 150-300° C. and the calcination time is 0.5-3 h.

6. The method for preparing the high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1, characterized in that: In step (3), the microwave power is 100-300W.

7. The method for preparing the high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1, characterized in that: The temperature in step (3) is 900-1100°C.

8. The method for preparing the high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1, characterized in that: In step (3), the rotation speed is 60-80 r / min.

9. The method for preparing the high-efficiency, low-toxic and environmentally friendly gold dissolving agent according to claim 1, characterized in that: The reaction time in step (3) is 4-6 hours.

10. An application of a high-efficiency, low-toxic and environmentally friendly gold dissolving agent prepared according to any one of claims 4 to 9 in precious metal production, characterized in that: Applications include the extraction of gold and silver from gold- and silver-containing ores; the extraction of gold and silver from gold- and silver-containing smelting waste slag or waste materials; and the extraction of platinum, palladium, indium and other ores.

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