Method for treating gold-containing waste residues through synergistic matching of copper smelting slag

Abstract

The invention discloses a method for treating gold-bearing waste residues through synergistic matching of copper smelting slag, and relates to the technical field of copper smelting slag treatment.The method comprises the following operation steps that S1, copper smelting slag treatment is conducted, specifically, the copper smelting slag is subjected to crushing, grinding and magnetic separation; s2, gold-containing waste residue treatment, wherein the gold-containing waste residue is subjected to screening gravity separation and stirring ore grinding; s3, mixing the ingredients; s4, smelting is conducted, specifically, the mixed materials are smelted; s5, slag and metal are separated; s6, further treatment of the furnace slag: firstly carrying out water quenching treatment on the discharged furnace slag, and then carrying out magnetic separation and flotation treatment; s7, electrolysis is conducted, specifically, the cast anode plate is put into an electrolytic bath to be electrolyzed; and S8, anode mud treatment, wherein the electrolyzed anode mud is treated. According to the method for treating the gold-bearing waste residues through collaborative matching of the copper smelting slag, collaborative recovery of various valuable metals in the copper smelting slag and the gold-bearing waste residues is achieved, the comprehensive utilization rate of resources is increased, and the efficiency of the technological process is also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of copper smelting slag treatment, and particularly relates to a method for co-processing gold-containing waste slag with copper smelting slag. Background Art

[0002] Copper is an important basic material with a large and continuously growing consumption. In 2019, the output of refined copper in China was 9.784 million tons, a 5.5% increase compared with 2018. However, the apparent domestic demand was 12.8 million tons, an increase of 2.5% compared with the same period of the previous year. With the exploitation of copper resources, the grade of copper ore has reached 0.2%-0.3%, and copper metallurgy is facing severe challenges. Therefore, it is becoming increasingly important to recover valuable metals from copper smelting slag. Under the condition of oxygen-enriched smelting of copper, a large amount of high-melting-point magnetite will be produced, deteriorating the properties of the slag and resulting in high copper content in the slag. At present, copper impoverishment technology only considers the recovery of copper and does not consider the recovery of other valuable metals such as lead and zinc. Moreover, almost all of the high-lead-zinc converter slag / refining slag returns to the smelting process, and Pb and Zn circulate in the smelting process, resulting in high impurity content in copper matte, reducing the quality of copper matte and increasing the impurity removal pressure in subsequent processes.

[0003] When the existing process smelts and recovers copper smelting slag and gold-containing waste slag, it cannot co-recover other valuable metals in the waste slag, resulting in insufficient utilization of metal resources. Moreover, a large amount of additives and treatment reagents are consumed in the smelting process, making the process cost high. To solve the deficiencies of the existing technology, we propose a method for co-processing gold-containing waste slag with copper smelting slag. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for co-processing gold-containing waste slag with copper smelting slag, which can effectively solve the problems in the background art.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for co-processing gold-containing waste slag with copper smelting slag, comprising the following operating steps:

[0007] S1: Treatment of copper smelting slag: The copper smelting slag is preliminarily crushed by a jaw crusher, further crushed by a cone crusher, ground by a ball mill, and then the ground copper smelting slag is subjected to magnetic separation by a magnetic separator to separate the magnetic substances therein;

[0008] S2: Treatment of gold-containing waste slag: The gold-containing waste slag is screened to remove large impurities and foreign matters therein, and then the gravity separation method is adopted to preliminarily enrich gold by a shaking table or a chute. After that, the gold-containing waste slag after gravity separation is put into a stirred mill for stirred milling to refine the particle size of the gold-containing waste slag;

[0009] S3: batching and mixing: chemical composition analysis is performed on the pre-treated copper smelting slag and gold-containing waste slag, and then batching is performed in a certain proportion according to the composition analysis results of the copper smelting slag and the gold-containing waste slag, and an appropriate amount of flux is added to adjust the pH value of the slag, and then the prepared materials are added to the mixing device for full mixing;

[0010] S4: Melting: The mixed materials are transported to the oxygen-enriched top-blown smelting furnace through a belt conveyor, oxygen-enriched air is introduced into the smelting furnace, and a proper amount of coal powder is sprayed into the furnace as fuel using a burner and a spray gun, so that the materials undergo a series of chemical reactions at high temperature;

[0011] S5: Separation of slag and metal: After smelting, the high-temperature melt is placed into a sedimentation separation tank through the slag outlet and the copper outlet. The slag is allowed to stand in the sedimentation tank for a period of time, so that the slag floats to the upper layer and the metal phase sinks to the bottom. The slag on the upper layer is slowly discharged through a siphon device, and the metal phase at the bottom is cast into anode plates through a casting device;

[0012] S6: Further treatment of slag: The discharged slag is firstly subjected to water quenching treatment, and then the slag after water quenching is treated by a combination of magnetic separation and flotation;

[0013] S7: Electrolysis: Place the cast anode plate into the electrolytic cell and connect it to direct current. During the electrolysis process, copper sulfate and sulfuric acid solution need to be added to control the concentration and pH stability of the electrolyte. During the electrolysis process, copper ions gradually deposit on the cathode plate to form cathode copper.

[0014] S8: Anode mud treatment: collect the anode mud generated in the electrolysis process, and use a mixed solution of hydrochloric acid and nitric acid for leaching. After the leaching is completed, use a filtering device to separate the solution from the residue, and then use deionized water to wash the residue multiple times. The residue after washing is the preliminary purified gold mud, which is smelted and cast into a mold after smelting to obtain gold with higher purity.

[0015] Preferably, in S1, the jaw crusher needs to crush the copper smelting slag to a particle size of about 50 mm, the cone crusher needs to further crush the copper smelting slag to less than 10 mm, and the ball mill grinds the copper smelting slag to a particle size of less than 75 μm with a content exceeding 80%.

[0016] Preferably, in S2, the gold-containing waste slag is screened using a vibrating screen.

[0017] Preferably, in S3, the chemical composition analysis is performed using an X-ray fluorescence spectrometer, the mass ratio of copper smelting slag to gold-containing waste slag is 3:1 to 5:1, limestone or quartz is used as flux, the pH value of the slag is controlled between 1.0-1.2, a stirring paddle and a scraper are provided inside the mixing device, and the stirring and mixing time is 15-30 minutes.

[0018] Preferably, in the step S4, the oxygen concentration of the oxygen-enriched air is 30%-40%, the smelting temperature is 1250°C-1350°C. During the smelting process, temperature sensors such as thermocouples are required to monitor the temperature in the furnace in real time, and the smelting time is 2-3 hours.

[0019] Preferably, in the step S5, the sedimentation and static time is 1-2 hours.

[0020] Preferably, in the step S6, a flotation agent needs to be added during the flotation process. The flotation agent includes a collector and a frother.

[0021] Preferably, in the step S7, the electrolytic cell needs to be cleaned and inspected before installing the anode plate and the cathode plate. The electrolysis temperature is 50°C-60°C, and the electrolysis time is 3-5 days.

[0022] Preferably, in the step S8, the volume ratio of hydrochloric acid to nitric acid in the mixture is 3:1. Borax needs to be added as a flux during the smelting process of the gold mud. The smelting temperature is 1200°C-1300°C, and the smelting time is 1-2 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The method of the present invention realizes the synergistic recovery of various valuable metals in copper smelting slag and gold-containing waste slag. It not only efficiently recovers gold from the gold-containing waste slag, but also recovers valuable metals such as iron, copper, and zinc from the copper smelting slag, improving the comprehensive utilization rate of resources. Using the copper smelting slag as an auxiliary raw material for the treatment of gold-containing waste slag consumes a large amount of copper smelting slag, reducing its occupation of land resources and potential pollution to the environment. At the same time, recovering gold from the gold-containing waste slag avoids the waste of gold resources.

[0025] 2. The method of the present invention properly treats the copper smelting slag and the gold-containing waste slag, avoiding the pollution of the two waste slags to the soil, water body and air when they are randomly stacked. Through the comprehensive utilization of the slag, using it as a raw material for building materials reduces the emission of solid waste, realizes the reduction and resource utilization of waste. Using the components in the copper smelting slag to participate in the smelting reaction of the gold-containing waste slag reduces the usage amount of additional additives and treatment reagents. The high-purity gold recovered from the gold-containing waste slag and other valuable metals recovered from the slag also bring considerable economic benefits to the enterprise.

[0026] 3. In the process of co-smelting of the method of the present invention, copper smelting slag and gold-containing waste residue interact with each other to form a slag system that is conducive to gold enrichment and separation. Appropriate slag composition and properties reduce the melting point and viscosity of the slag, improve the smelting reaction rate and the gold recovery rate. At the same time, the application of the oxygen-enriched top-blown smelting technology further improves the smelting efficiency and shortens the smelting time. This method combines the treatment of copper smelting slag and gold-containing waste residue, avoids the cumbersome processes of separately treating the two waste residues, simplifies the technological process, and improves the continuity and stability of the entire treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] The present invention relates to a method for co-processing gold-containing waste residue with copper smelting slag, including the following operating steps:

[0030] S1: Treatment of copper smelting slag: The copper smelting slag is initially crushed using a jaw crusher to crush the particle size of the copper smelting slag to about 50 mm, and then further crushed using a cone crusher to crush the particle size of the copper smelting slag to less than 10 mm. Then, it is ground using a ball mill to make the particle size of the copper smelting slag reach a content ratio of more than 80% with a particle size below 75 μm. Then, the ground copper smelting slag is subjected to magnetic separation using a magnetic separator to separate the magnetic substances therein.

[0031] S2: Treatment of gold-containing waste residue: The gold-containing waste residue is screened using a vibrating screen to remove large impurities and foreign matters therein. Then, the gravity separation method is adopted to initially enrich gold through a shaking table or a chute. The shaking table uses the asymmetric reciprocating motion of the table surface and the flushing action of water flow to make mineral particles with different densities produce different movement trajectories on the table surface, thereby realizing the initial enrichment of gold. The chute uses the flow of pulp on the inclined chute surface to make the gold particles with a larger density precipitate at the bottom of the chute, and the gold is collected by periodically scraping the precipitate at the bottom of the chute. After that, the gravity-separated gold-containing waste residue is put into a stirred mill for stirred milling to refine the particle size of the gold-containing waste residue, increase the exposure area of gold particles, and improve their reaction activity.

[0032] S3: Batching and mixing: The chemical composition of the pretreated copper smelting slag and gold-containing waste slag is analyzed by X-ray fluorescence spectrometer to accurately determine the content of each element therein, providing accurate data basis for batching. According to the composition analysis results of the copper smelting slag and the gold-containing waste slag, the batching is carried out in a ratio of 3:1 to 5:1 between copper smelting slag and gold-containing waste slag. At the same time, an appropriate amount of limestone and quartz stone are added as flux to adjust the pH value of the slag so that the pH value of the slag is controlled between 1.0-1.2. Then the prepared materials are added to the mixing device for sufficient mixing. The mixing time is 15-30 minutes.

[0033] S4: Smelting: The mixed materials are conveyed to the oxygen-enriched top-blown smelting furnace through a belt conveyor, and oxygen-enriched air is introduced into the smelting furnace. The oxygen concentration in the oxygen-enriched air is controlled at 30%-40%. The oxygen-enriched air is sprayed into the furnace through a spray gun installed on the top of the furnace, and fully contacts with the materials to improve the combustion efficiency and the smelting reaction speed. A proper amount of coal powder is sprayed into the furnace as fuel using a burner and a spray gun to maintain the smelting temperature at 1250℃-1350℃. During the smelting process, a temperature sensor such as a thermocouple is used to monitor the temperature in the furnace in real time. By adjusting the fuel supply and the oxygen intake, the temperature is accurately controlled to allow the material to undergo a series of chemical reactions at high temperatures. The iron oxides in the copper smelting slag react with impurities such as sulfur in the gold-containing waste slag to form a low-melting-point slag phase, and gold is gradually enriched in the metal phase at high temperatures. Because the chemical properties of gold are stable, it is not easy to react with other substances, and it will form alloys with other metals in the molten state. The smelting time is 2-3 hours.

[0034] S5: Separation of slag and metal: After smelting, the high-temperature melt is placed into a sedimentation separation tank through the slag outlet and the copper outlet. It is left to stand in the sedimentation tank for 1-2 hours to allow the slag to float to the upper layer and the metal phase to sink to the bottom. The slag on the upper layer is then slowly discharged through a siphon device, and the metal phase at the bottom is cast into an anode plate through a casting equipment for subsequent electrolytic refining.

[0035] S6: Further treatment of slag: The discharged slag is first quenched with water. The high-temperature slag flows into the water quenching pool through a chute. A large amount of cooling water in the water quenching pool quickly contacts the slag, causing the slag to quickly cool into granules. During the water quenching process, the slag undergoes rapid cooling and shrinkage to form a porous structure, which is convenient for subsequent processing. The slag after water quenching is then treated by a process combining magnetic separation and flotation. First, magnetic separation is performed to recover the residual ferromagnetic material. The slag after magnetic separation then enters the flotation machine for flotation. By adding collectors and bubbling agents as flotation agents, the valuable metals in the slag are attached to the bubbles and float to the surface of the slurry to form a foam layer, thereby separating it from the gangue. The treated slag can be used as a raw material for building materials, such as for the production of cement and bricks.

[0036] S7: Electrolysis: Place the cast anode plates into the electrolytic cell, connect the direct current power supply. The temperature of electrolysis is 50°C - 60°C. Under the action of the direct current, metals such as copper in the anode plates dissolve into the solution and undergo oxidation reactions: Cu - 2e- = Cu2+. Gold precipitates at the bottom of the electrolytic cell in the form of anode slime. During the electrolysis process, copper sulfate and sulfuric acid solutions need to be added to control the stability of the concentration and acidity of the electrolyte. The electrolysis time is generally 3 - 5 days. During the electrolysis process, copper ions in the solution gain electrons at the cathode and undergo reduction reactions: Cu2+ + 2e- = Cu. Copper ions gradually deposit on the cathode plates to form cathode copper. When the cathode copper reaches a certain thickness, it is taken out from the electrolytic cell for cleaning and drying.

[0037] S8: Treatment of Anode Slime: Collect the anode slime generated during electrolysis and leach it with a mixed solution of hydrochloric acid and nitric acid. The volume ratio of hydrochloric acid to nitric acid in the mixture is 3:1. During the leaching process, the impurity metals in the anode slime react with the mixed acid and dissolve into the solution, while gold does not react with the mixed acid and remains in the residue. After the leaching is completed, a filtration device is used to separate the solution from the residue. Then, the residue is washed multiple times with deionized water to remove the residual acid and impurities on the surface. The washed residue is the preliminarily purified gold mud. The gold mud is smelted, and an appropriate amount of flux such as borax is added at high temperature. The smelting temperature is controlled at 1200 - 1300°C, and the smelting time is 1 - 2 hours. After smelting, it is cast into a mold to obtain gold with a higher purity.

[0038] This method realizes the collaborative recovery of various valuable metals from copper smelting slag and gold-containing waste slag. It not only efficiently recovers gold from the gold-containing waste slag but also recovers valuable metals such as iron, copper, and zinc from the copper smelting slag, improving the comprehensive utilization rate of resources. Moreover, this method combines the treatment of copper smelting slag and gold-containing waste slag, avoiding the cumbersome processes of separately treating the two types of waste slag, simplifying the technological process, and improving the continuity and stability of the entire treatment process.

[0039] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for co - treating gold - containing waste residue by copper smelting slag, characterized in that: The following operating steps are included: S1: Treatment of copper smelting slag: The copper smelting slag is initially crushed using a jaw crusher, further crushed using a cone crusher, ground using a ball mill, and then the ground copper smelting slag is subjected to magnetic separation using a magnetic separator to separate the magnetic substances therein; S2: Treatment of gold-containing waste residue: The gold-containing waste residue is screened to remove large impurities and foreign matters therein, and then the gravity separation method is adopted to preliminarily enrich gold through a shaking table or a chute. After that, the gravity-separated gold-containing waste residue is put into a stirred mill for stirred grinding to refine the particle size of the gold-containing waste residue; S3: Batching and mixing: The chemical compositions of the pretreated copper smelting slag and the gold-containing waste residue are analyzed, and then, according to the component analysis results of the copper smelting slag and the gold-containing waste residue, batching is carried out in a certain proportion, and an appropriate amount of flux is added to adjust the acidity and alkalinity of the slag. Then, the prepared materials are added to a mixing device for thorough mixing; S4: Smelting: The mixed materials are conveyed to a top-blown oxygen-enriched smelting furnace through a belt conveyor, oxygen-enriched air is introduced into the smelting furnace, and an appropriate amount of pulverized coal is sprayed into the furnace as fuel using a burner and a lance to enable the materials to undergo a series of chemical reactions at high temperature; S5: Separation of slag and metal: After smelting, the high-temperature melt is put into a sedimentation separation tank through a slag outlet and a copper outlet, and left to stand in the sedimentation tank for a period of time to make the slag float to the upper layer and the metal phase sink to the bottom. Then, the upper-layer slag is slowly discharged through a siphon device, and the bottom metal phase is cast into anode plates through a casting device; S6: Further treatment of slag: The discharged slag is first subjected to water quenching treatment, and then a process combining magnetic separation and flotation is adopted to treat the water-quenched slag; S7: Electrolysis: The cast anode plates are put into an electrolytic cell, and direct current is switched on. During the electrolysis process, copper sulfate and sulfuric acid solutions need to be added to control the stability of the concentration and acidity and alkalinity of the electrolyte. During the electrolysis process, copper ions are gradually deposited on the cathode plate to form cathode copper; S8: Treatment of anode slime: The anode slime generated during the electrolysis process is collected and leached using a solution mixed with hydrochloric acid and nitric acid. After leaching, a filtering device is used to separate the solution from the residue, and then the residue is washed multiple times with deionized water. The washed residue is the preliminarily purified gold slime, and the gold slime is smelted and then cast into a mold to obtain gold with a higher purity.

2. The method for co - treating gold - containing waste residue with copper smelting slag according to claim 1, characterized in that: In the above S1, the jaw crusher needs to crush the copper smelting slag to a particle size of about 50 mm, the cone crusher needs to further finely crush the copper smelting slag to less than 10 mm, and the ball mill grinds the copper smelting slag to a content of more than 80% with a particle size of less than 75 μm.

3. A method for co-processing gold-containing waste residues with copper smelting slag according to claim 1, characterized in that: In the above S2, the gold-containing waste residue is screened using a vibrating screen.

4. A method for co-processing gold-containing waste residues with copper smelting slag according to claim 1, characterized in that: In the above S3, the chemical composition analysis is carried out using an X-ray fluorescence spectrometer device. The mass ratio of the copper smelting slag to the gold-containing waste residue is 3:1 to 5:

1. The flux uses limestone or quartzite, the acidity and alkalinity of the slag is controlled between 1.0 and 1.2, the mixing device is internally provided with stirring paddles and scrapers, and the stirring and mixing time is 15 - 30 minutes.

5. A method for co - treating gold - containing waste residue with copper smelting slag according to claim 1, characterized in that: In S4, the oxygen concentration of the oxygen-enriched air is 30%-40%, the smelting temperature is 1250°C-1350°C. During the smelting process, temperature sensors such as thermocouples are needed to monitor the temperature in the furnace in real time, and the smelting time is 2-3 hours.

6. The method for co - treating gold - containing waste residue with copper smelting slag according to claim 1, wherein: In S5, the sedimentation and static time is 1-2 hours.

7. A method for co - treating gold - containing waste residue with copper smelting slag according to claim 1, characterized in that: In S6, a flotation agent needs to be added during the flotation process, and the flotation agent includes a collector and a frother.

8. A method for co - treating gold - containing waste residue with copper smelting slag according to claim 1, characterized in that: In S7, the electrolytic cell needs to be cleaned and inspected before installing the anode plate and the cathode plate. The electrolysis temperature is 50°C-60°C, and the electrolysis time is 3-5 days.

9. A method for co - treating gold - containing waste residues with copper smelting slag according to claim 1, characterized in that: In S8, the volume ratio of hydrochloric acid to nitric acid in the mixture is 3:

1. Borax needs to be added as a flux during the smelting process of the gold mud. The smelting temperature is 1200°C-1300°C, and the smelting time is 1-2 hours.

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