A sulfide ore beneficiation process for copper extraction and arsenic reduction

Abstract

The present invention belongs to the field of mineral processing technology, and specifically relates to a sulfide ore beneficiation process for copper extraction and arsenic reduction, comprising the steps of ore feeding, regrinding, lime slurry mixing, stirring, roughing, and concentrating. In combination with a self-developed flotation machine, reverse flotation can be used to select copper in low-temperature environments such as winter, while simultaneously achieving the purpose of arsenic reduction. Furthermore, "regrinding + stirring" is used to further remove the drug. During the reselection process, the pH value of the ore pulp is reasonably controlled at 11.0. Without the addition of any reagents, the natural floatability of the minerals is relied upon to achieve rapid enrichment of the dissociated copper and sulfur minerals, thereby obtaining a portion of low-grade copper concentrate, achieving the goal of recovering as much as possible, while also obtaining high-quality sulfur concentrate.

Description

Technical Field

[0001] This solution belongs to the field of mineral processing technology, and specifically relates to a sulphur ore beneficiation process for extracting copper and reducing arsenic. Background Art

[0002] Arsenic is a major impurity in the copper ore dressing process and can enter the copper concentrate and tailings. Therefore, copper ore dressing products with excessively high arsenic content not only significantly affect their quality and price, but also face the challenge of discharging and decontaminating the arsenic that cannot be recycled. Currently, different methods for reducing and removing arsenic are used for different types of arsenic-containing minerals. Arsenopyrite, the main arsenic-containing mineral, often coexists closely with chalcopyrite, pyrite, and fluorite in copper deposits. During the beneficiation process, arsenic in copper concentrate is often reduced through fine grinding and the addition of effective inhibitors. Effective inhibitors for arsenopyrite include lime, sodium humate, hydrogen peroxide, and cyanide. Tetrahedrite and thiochlochalcogenide are the most predominant arsenic-containing copper minerals in copper deposits, and are sometimes even the target minerals for copper recovery. They often coexist closely with arsenic-free copper sulfide minerals such as chalcopyrite and bornite, making their separation and removal very difficult.

[0003] Currently, the following methods are commonly used to remove arsenic: identifying the occurrence and occurrence of arsenic-containing copper ore within the ore body, and then blending it with arsenic-free copper ore during beneficiation to reduce the arsenic content of the ore. However, this method requires a lot of work and is costly to perform in the early stages of screening.

[0004] In addition, patent number CN201010147864.8 discloses a flotation separation method for pyrite and arsenopyrite. For the flotation separation of sulfur and arsenic in arsenic-containing pyrite, the slurry is first adjusted by adjusting the slurry pH to 9-10, and the slurry potential is adjusted to 350-380mV by adding oxidizing agents such as sodium persulfate and calcium hypochlorite. Air is then added to increase the oxygen content in the slurry and stabilize the electrochemical conditions for mineral flotation. During the flotation separation of pyrite and arsenopyrite, the slurry potential is stabilized by adding oxidizing agents such as sodium persulfate and calcium hypochlorite. Based on the principles of electrochemical flotation technology, a new collector, diphenylamino dithiophosphoric acid, and adjusting agents, such as water glass and sodium humate, are used to inhibit arsenopyrite, allowing arsenopyrite, pyrite, and other pyrite ores to selectively interact with the reagents in the subsequent flotation process. This method involves flotation separation of pyrite and arsenopyrite from the ore, producing a sulfur concentrate with a low arsenic content. However, this solution utilizes flotation, requires the addition of chemicals, and requires electricity, making it very costly. Furthermore, winter temperatures significantly impact the performance of the flotation cell, requiring the slurry to maintain a constant temperature for optimal arsenic removal. Furthermore, as the flotation cell is a crucial piece of equipment in the mineral processing process, improvements to the flotation cell, combined with the process itself, can further enhance arsenic reduction. Summary of the Invention

[0005] This solution provides a sulphur ore beneficiation process that can effectively reduce arsenic by flotation alone.

[0006] In order to achieve the above-mentioned purpose, this solution provides a sulfide ore beneficiation process for copper extraction and arsenic reduction, comprising the following steps:

[0007] Step S10, feeding: mixing and reducing the sulfur concentrate slurry sample, and controlling the concentration at about 30%;

[0008] Step S20, re-grinding: feeding the feed in step S10 into a conical ball mill for grinding to obtain feed for flotation operation;

[0009] Step S30, lime slurry preparation: pour the flotation feed obtained in step S20 into a 1.5L flotation machine, add lime and prepare the slurry, and control the pH value to 11.0;

[0010] Step S40, stirring: stirring the slurry in step S30 in a flotation machine for 20 minutes;

[0011] Step S50, roughing: the flotation machine is aerated to utilize the natural floatability of the minerals for reverse flotation, and the foam is scraped for 5 minutes to obtain the coarse concentrate and tailings. The tailings are high-quality sulfur concentrate;

[0012] Step S60, concentrating: feeding the coarse concentrate obtained in step S50 into a 0.5L flotation machine for concentrating to obtain concentrate and middlings, wherein the concentrate is a low-grade copper concentrate.

[0013] The present invention only requires reverse flotation for copper separation, while simultaneously achieving the goal of arsenic reduction. Furthermore, "regrinding + stirring" is used to further remove the drug. During the re-separation process, the pH value of the ore pulp is reasonably controlled at 11.0. Without adding any reagents, the natural floatability of the minerals is utilized to achieve rapid enrichment of the dissociated copper and sulfur minerals, thereby obtaining a portion of low-grade copper concentrate, achieving the goal of fully recovering what can be recovered, and simultaneously obtaining a high-quality sulfur concentrate.

[0014] Furthermore, in step S50, during roughing, the pulp is heated and maintained at 40-50° C. Long-term experiments have shown that arsenic reduction can be better achieved at this temperature.

[0015] Furthermore, the flotation machine includes a box body, a drive motor, an impeller, a stirring mechanism and a sleeve, the drive motor is fixed on the box body, the output shaft of the drive motor passes through the sleeve, the impeller is coaxially connected to the output shaft of the drive motor, and the impeller is located in the sleeve to form a pump, and the stirring mechanism is fixed to the free end of the output shaft of the drive motor; it also includes an inner box, the inner box is arranged in the box body, and an insulation chamber is formed between the inner box and the box body, and a hot air pipe is provided in the insulation chamber; the sleeve and the insulation chamber are connected by a flexible air inlet pipe; the inner box includes a fixed plate and at least one movable plate, the movable plate and the fixed plate are sealed by a flexible part, and an elastic part is provided between the movable plate and the box body; an air outlet pipe is also provided on the top of the box body, a strip-shaped air outlet is provided on the side wall of the air outlet pipe, and the air outlet pipe is connected to the insulation chamber.

[0016] The principle of this solution is:

[0017] First, a hot air blower is connected to the insulation chamber via a hot air duct. The slurry and reagents are then poured into the chamber. The drive motor is activated, driving the stirring mechanism to mix the slurry. Simultaneously, the impeller rotates, creating a pressure differential that pumps the hot air from the insulation chamber into the chamber. The hot air fully contacts the minerals, forming mineralized bubbles that move upward into the separation zone, where they accumulate and form a foam layer. Finally, an outlet pipe at the top blows the foam layer out into a collection tank, leaving the remaining product as the desired product.

[0018] Compared to traditional flotation machines, this design primarily differs from traditional flotation machines in the addition of an inner chamber, creating an insulated chamber that heats the slurry and achieves improved screening efficiency, especially in winter. The inner chamber features movable plates and flexible components, working in conjunction with springs. As the slurry level decreases, the plates move, reducing the effective volume of the chamber, ensuring the foam layer remains separated. The air inlet pipe is connected to the casing, allowing hot air to enter the chamber. Combined with the stirring mechanism, this air enters the chamber and heats the minerals, resulting in excellent heating efficiency. Finally, the traditional flotation plates are replaced with outlet pipes, which remove the foam layer through airflow rather than physical scraping. This offers two key advantages: 1. It prevents slurry from adhering to the plates during physical scraping, which increases the plate size and results in the removal of slurry not in the foam layer; 2. The hot air from the outlet pipe forms a wind curtain, significantly slowing the temperature drop within the chamber, thereby ensuring optimal separation efficiency.

[0019] Furthermore, the invention further comprises an adjusting motor, which is fixed to the housing, and the air outlet pipe is rotatably arranged on the housing, and the air outlet pipe is coaxially connected to the output shaft of the adjusting motor. The angle of the air outlet pipe can be adjusted by adjusting the motor, which is easy to operate.

[0020] Furthermore, the elastic member is a stainless steel spring, which has good elasticity and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the flotation machine in the embodiment of the present invention

[0022] Figure 2 Schematic diagram of the structure of the flotation machine in an embodiment of the present invention.

[0023] Figure 3 1 is a top view of a flotation machine in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is a further detailed description through specific implementation methods:

[0025] The figure marks in the drawings of the specification include: box body 10, inner box 20, elastic part 21, hot air pipe 22, flexible part 23, air inlet pipe 24, drive motor 30, slurry inlet pipe 31, stirring mechanism 32, adjustment motor 40, air outlet pipe 41, air outlet 42, and collection tank 50.

[0026] Example

[0027] A sulphur ore beneficiation process for extracting copper and reducing arsenic, comprising the following steps:

[0028] Step S10, feeding: mixing and reducing the sulfur concentrate slurry sample, and controlling the concentration at about 30%;

[0029] Step S20, regrinding: feeding the ore in step S10 into a 240*90 conical ball mill for grinding to obtain ore for flotation operation; the fineness is controlled at 40-60μm;

[0030] Step S30, lime slurry preparation: pour the flotation feed obtained in step S20 into a 1.5L flotation machine, add lime and prepare the slurry, and control the pH value to 11.0;

[0031] Step S40, stirring: stirring the slurry in step S30 in a flotation machine for 20 minutes;

[0032] Step S50, roughing: the flotation machine is aerated to utilize the natural floatability of the minerals for reverse flotation, and the foam is scraped for 5 minutes to obtain the coarse concentrate and tailings. The tailings are high-quality sulfur concentrate;

[0033] Step S60, concentrating: feeding the coarse concentrate obtained in step S50 into a 0.5L flotation machine for concentrating to obtain concentrate and middlings, wherein the concentrate is a low-grade copper concentrate.

[0034] Under the same low temperature environment of 0°C, the process of Example 1 and the traditional process are used, and the measured data are shown in the following table:

[0035]

[0036] This demonstrates that this solution utilizes reverse flotation to select copper while simultaneously achieving arsenic reduction. Furthermore, "regrinding + stirring" is employed to further remove the arsenic. During the reselection process, the pH value of the ore pulp is rationally controlled at 11.0. Without the addition of any reagents, the natural flotation of the minerals is utilized to rapidly enrich the dissociated copper and sulfur minerals, obtaining a portion of low-grade copper concentrate, achieving the goal of fully recovering the ore, while also obtaining a high-quality sulfur concentrate.

[0037] like Figure 1 、 Figure 2 and Figure 3 As shown in the figure, let's focus on introducing the matching flotation machine.

[0038] It is basically the same as an existing flotation machine, including a housing 10, a drive motor 30, an impeller, a stirring mechanism 32, and a sleeve. The drive motor 30 is fixed to the housing 10, and the output shaft of the drive motor 30 passes through the sleeve. The impeller is coaxially connected to the output shaft of the drive motor 30 and is located within the sleeve to form a pump. The stirring mechanism 32 is fixed to the lowest end of the output shaft of the drive motor 30. In addition, there are existing structures such as the slurry inlet pipe 31, which will not be described in detail one by one. Reference is made to the existing flotation machine.

[0039] The main difference is that it also includes an inner box 20, which is slightly smaller than the main body 10 and is welded to the main body 10. This creates a heat-insulating chamber between the inner box 20 and the main body 10, within which a hot air duct 22 is installed. During use, the hot air duct 22 connects to the hot air blower.

[0040] The sleeve and the insulation chamber are connected by a flexible air inlet pipe 24. This increases the slurry temperature, allowing for rapid oxidation of the pyrite surface and increasing its hydrophilicity. This elevated slurry temperature also improves the activation efficiency of sphalerite by copper sulfate, shortening the flotation process and ensuring zinc recovery. If necessary, a thermometer can be positioned within the housing 10 to facilitate monitoring of the slurry temperature. The flexible air inlet pipe 24 is easily bendable, and a foldable design is also possible.

[0041] The inner box 20 consists of a fixed plate and three movable plates, sealed between the movable and fixed plates by flexible members 23. Flexible members 23 can be appropriately long, with loops at the top and bottom, and are made of rubber for high deformability. Furthermore, elastic members 21 are provided between the movable plates and the box body 10. Ordinary stainless steel springs can be used for this elasticity, ensuring a long service life.

[0042] An air outlet pipe 41 is also provided on the top of the box body 10, and a strip-shaped air outlet 42 is provided on the side wall of the air outlet pipe 41, and the air outlet pipe 41 is connected to the heat preservation chamber. It is worth noting that the air outlet 42 of the air outlet pipe 41 should be as level as possible with the surface of the slurry. The size of the air outlet 42 should not be too large, otherwise the wind force may not be enough. People in this field can adjust it according to actual conditions. In addition, an adjustment motor 40 can be set separately, using a servo motor, which can be easily adjusted in two directions. Fix the adjustment motor 40 on the box body 10, and then rotate the air outlet pipe 41 to set it on the box body 10, and the air outlet pipe 41 is coaxially connected to the output shaft of the adjustment motor 40. In this way, the angle of the air outlet pipe 41 can be adjusted by adjusting the motor 40, which is easy to operate.

[0043] When in use, first connect the hot air blower to the heat preservation chamber through the hot air pipe, then pour the slurry and reagent into the box body 10, start the drive motor, the motor will drive the stirring mechanism 32 to mix, and at the same time, the impeller will rotate together, creating a pressure difference, and pumping the hot air in the heat preservation chamber into the box body. The hot air fully contacts the minerals, forming mineralized bubbles, which move upward into the separation zone and enrich to form a foam layer. Figure 1 As shown, when the ore pulp in the casing 10 becomes less and less, the movable plate will move, thereby reducing the effective volume of the casing, so that the foam layer can always be separated. Finally, the air outlet pipe at the top blows the foam layer into the collecting tank 50 for subsequent processing.

[0044] The above is only an embodiment of the present invention, and the common knowledge such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A sulphur ore beneficiation process for copper extraction and arsenic reduction, characterized in that: The following steps are involved: Step S10, feeding: mixing and reducing the sulfur concentrate slurry sample, and controlling the concentration at 30%; Step S20, re-grinding: feeding the feed in step S10 into a conical ball mill for grinding to obtain feed for flotation operation; Step S30, lime slurry preparation: pour the flotation feed obtained in step S20 into a 1.5L flotation machine, add lime and prepare the slurry, and control the pH value to 11.0; Step S40, stirring: stirring the slurry in step S30 in the flotation machine for 20 minutes; the flotation machine includes a box, a drive motor, an impeller, a stirring mechanism and a sleeve, the drive motor is fixed on the box, the output shaft of the drive motor passes through the sleeve, the impeller is coaxially connected to the output shaft of the drive motor, and the impeller is located in the sleeve to form a pump, and the stirring mechanism is fixed to the free end of the output shaft of the drive motor; it also includes an inner box, the inner box is arranged in the box, and a heat preservation chamber is formed between the inner box and the box, and a hot air pipe is provided in the heat preservation chamber; the sleeve and the heat preservation chamber are connected by a flexible air inlet pipe; the inner box includes a fixed plate and at least one movable plate, the movable plate and the fixed plate are sealed by a flexible member, and an elastic member is provided between the movable plate and the box; an air outlet pipe is also provided on the top of the box, and a strip-shaped air outlet is provided on the side wall of the air outlet pipe, the hot air blown out by the air outlet pipe forms an air curtain, and the air outlet pipe is connected to the heat preservation chamber; Step S50, roughing: the flotation machine is aerated to utilize the natural floatability of the minerals for reverse flotation, and the foam is scraped for 5 minutes to obtain the coarse concentrate and tailings. The tailings are high-quality sulfur concentrate; Step S60, concentrating: feeding the coarse concentrate obtained in step S50 into a 0.5L flotation machine for concentrating to obtain concentrate and middlings, wherein the concentrate is a low-grade copper concentrate.

2. A sulphur ore beneficiation process for copper extraction and arsenic reduction according to claim 1, characterized in that: In step S50, during roughing, the slurry is heated and maintained at 40-50°C.

3. A sulphur ore beneficiation process for copper extraction and arsenic reduction according to claim 1, characterized in that: It also includes an adjusting motor, which is fixed on the box body. The air outlet pipe is rotatably arranged on the box body, and the air outlet pipe is coaxially connected to the output shaft of the adjusting motor.

4. The sulfide ore beneficiation process for copper extraction and arsenic reduction according to claim 1, characterized in that: The elastic member is a stainless steel spring.

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