Method for flotation separation of copper oxide ore by sulphidizing roasting pretreatment

Abstract

The application provides a method for flotation separation of copper oxide ore sulfidation roasting pretreatment, and belongs to the technical field of mining and metallurgical engineering. The method increases the contact area of mixed gas and ore through suspension heating, accelerates the removal of crystal water in the ore, and converts the crystal water into copper oxide minerals with relatively uniform properties. Then, the ore itself is used for heat storage to react with a sulfidation agent in a suspended state to convert into copper sulfide minerals, so that the copper oxide minerals in the ore are efficiently sulfidized and reconstructed. Further, high-purity copper sulfide is obtained through flotation separation, and the recycling of copper in the copper oxide ore is effectively realized.

Description

Technical Field

[0001] This invention relates to the fields of mining and metallurgical engineering technology, and in particular to a method for flotation separation of copper oxide ore after sulfidation roasting pretreatment. Background Technology

[0002] Copper ore resources are the primary raw material for obtaining copper metal and are considered a strategic mineral resource of vital national demand. Oxide copper ore is an important component of my country's copper resources, accounting for approximately 20% of total reserves. However, oxide copper ore is characterized by its complex mineral composition, fine grain size, and susceptibility to mud formation, making its beneficiation extremely difficult. It is a typical complex and difficult-to-beneficiate mineral resource, and large-scale development and utilization have not yet been achieved. Therefore, developing new technologies and optimizing new processes are of great significance for the efficient beneficiation of oxide copper ore.

[0003] Patent CN202011457743.3 discloses a method for wet copper extraction from oxidized copper ore, proposing an acid leaching and extraction electrowinning process to obtain cathode copper. This method achieves effective copper recovery through a simple process flow; however, the consumption of leaching agent is relatively large, and the leaching residue generated after acid leaching still requires further treatment. Patent CN202011045552.6 provides an efficient copper recovery method for oxidized copper ore with different oxidation rates. For high-oxidized copper ore, a direct leaching method is used, while low-oxidized copper ore undergoes sulfide flotation followed by classification, magnetic separation, and acid leaching. This process classifies and recovers oxidized copper ore, improving the overall resource utilization rate and effectively solving the mud problem that restricts mineral processing. However, it still suffers from long separation processes and complex processing techniques. Patent CN202210615517.6 employs a method of first magnetic separation and then flotation, followed by heating and decomposing the flotation product to obtain copper oxide. While the process is simple and effective, yielding a high-purity product, it still has drawbacks: the use of multiple flotation reagents increases processing costs. Therefore, it is essential to develop a simple, economical, environmentally friendly, and high-performance beneficiation method to address the problems of long processes, low efficiency, and environmental pollution in current copper oxide ore beneficiation processes. Summary of the Invention

[0004] In view of this, the present invention provides a method for flotation separation of copper oxide ore after sulfidation roasting pretreatment. This method increases the contact area between the mixed gas and the ore through suspension heating, accelerating the removal of crystal water from the mineral and converting it into relatively homogeneous copper oxide minerals. Then, utilizing the heat stored in the ore itself, it reacts with a sulfiding agent in a suspended state to transform into copper sulfide minerals, achieving efficient sulfidation reconstruction of copper oxide minerals in the ore. Further flotation separation is then used to obtain high-purity copper sulfide, effectively realizing the recovery and utilization of copper from copper oxide ore.

[0005] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment includes the following steps:

[0006] Step 1: Crush the copper oxide ore to a particle size ≤ 2 mm, and then grind it until the portion with a particle size of -0.074 mm accounts for 70-90% of the total mass, to obtain copper oxide ore powder;

[0007] Step 2: The copper oxide ore powder is transported to the suspension roasting system for suspension roasting;

[0008] The suspension roasting system includes a heating decomposition device, a heat storage vulcanization device, and a cooling device;

[0009] The suspension roasting process is as follows: the copper oxide ore powder is preheated and dehydrated in a heating decomposition device; under negative pressure, the ore powder enters a regenerative sulfidation device from the top of the heating decomposition device, and nitrogen and hydrogen are introduced into the bottom of the regenerative sulfidation device. The ore powder is in a suspended state under the action of the airflow. A sulfiding agent is added from the top of the regenerative sulfidation device, and the ore powder is sulfided at a temperature of 300-800℃. The reaction equations involved in the sulfidation process are as follows:

[0010] Cu2CO3(OH)2→2CuO+H2O(g)+CO2(g) (1)

[0011] 2CuO + 2S → Cu2S + SO2(g) (2)

[0012] 2CuO+2FeS2→Cu2S+2FeS+SO2(g) (3);

[0013] Step 3: After the reaction in Step 2 is completed, the product is cooled by a cooler to obtain a roasted product; the roasted product is ground until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry;

[0014] Step 4: Add pH adjuster, collector and frother to the floatable slurry in sequence for flotation to obtain copper concentrate.

[0015] Furthermore, the copper oxide ore described in step 1 contains 0.5% to 5% Cu by mass percentage.

[0016] Furthermore, the preheating and dehydration process described in step 2 involves introducing natural gas and air into the heating and decomposition device for heating and combustion, with a preheating time of 5 to 10 minutes and a preheating temperature of 80 to 100°C.

[0017] Furthermore, the sulfiding agent mentioned in step 2 includes one of sulfur and pyrite.

[0018] Furthermore, the amount of sulfiding agent added in step 2 is 1.1 to 1.2 times the theoretical amount required for the complete reaction of sulfur in the sulfiding agent with copper oxide in the mineral powder.

[0019] Furthermore, the residence time of the copper oxide powder in the regenerative sulfidation device in step 2 is 30–65 min.

[0020] Furthermore, the concentration of the floatable slurry mentioned in step 3 is 25% to 30%.

[0021] Further, in step 4, the pH adjuster is HCl or NaOH, and the slurry is adjusted to pH = 6.5; the collector is ethyl xanthate, and the dosage is 300-600 g / t; the foaming agent is pine oil, and the dosage is 50-80 g / t.

[0022] Furthermore, the copper recovery rate of the copper concentrate is ≥90%.

[0023] The beneficial effects of this invention are:

[0024] This invention proposes a new technology of "sulfidation roasting pretreatment-flotation separation" for refractory copper oxide ores. Sulfidation roasting is used to reconstruct the phases and further facilitate efficient flotation separation. The process is simple and environmentally friendly, enabling the efficient recovery and utilization of copper minerals from refractory copper oxide ores.

[0025] 1. This invention creatively proposes to pre-treat copper oxide ore using roasting technology. The heating process decomposes, dehydrates, and removes impurities from various copper oxide minerals, transforming them into copper oxide minerals with relatively uniform properties, thereby improving the sulfidation reaction activity of the minerals.

[0026] 2. This invention proposes to sulfide copper oxide minerals, thereby achieving phase reconstruction during roasting, generating copper sulfide minerals for further flotation, simplifying the process, reducing the amount of flotation reagents used, and increasing the total copper recovery rate.

[0027] 3. The present invention uses suspension sulfidation roasting technology to keep the mineral particles in a suspended state, which increases the contact area between the ore and the gas, resulting in uniform heating and promoting a full and uniform reaction between the mineral and the sulfiding agent, thus achieving better mass and heat transfer effects.

[0028] 4. This invention leverages the advantages of combined beneficiation and smelting technology, achieving the transformation and reconstruction of mineral phases during the suspension roasting process, followed by efficient flotation separation. This simplifies the beneficiation process for oxidized copper ore, enables efficient recovery of copper ore, and provides technical support for the large-scale application of copper resources. Attached Figure Description

[0029] Figure 1 A schematic diagram of the flotation separation process for the pretreatment of copper oxide ore by sulfidation roasting;

[0030] Figure 2 This is a schematic diagram of the suspension roasting flotation process in an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions in the implementation of this patent will be clearly and completely described below with reference to the embodiments and accompanying drawings. It should be noted that the embodiments described in this invention are only for further explanation and illustration, and not for limiting their scope of application. Based on this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this patent.

[0032] A schematic diagram of the flotation separation process for the pretreatment of copper oxide ore by sulfidation roasting in this embodiment of the invention is shown below. Figure 1 As shown; the schematic diagram of the suspension roasting flotation process in this embodiment of the invention is as follows. Figure 2 As shown.

[0033] Example 1

[0034] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0035] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 1.26%, Fe 4.31%, CaO 13.23%, and SiO 262.54%.

[0036] Step 1: Crush the copper oxide ore to a particle size ≤ 2 mm, then grind it until the -0.074 mm portion accounts for 80% of the total mass, to obtain copper oxide ore powder;

[0037] Step 2: The mineral powder is transported to the suspension roasting system. Natural gas and air are introduced into the combustion station at the bottom of the thermal decomposition device for heating and combustion, preheating and dehydrating the mineral powder for 5 minutes at a temperature of 80°C. Under negative pressure, the mineral powder enters the regenerative sulfidation device from the top of the thermal decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device. The mineral powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, with the amount added being 1.1 times the amount that reacts completely with CuO in the mineral powder. The mineral powder is roasted at a temperature of 400°C for 40 minutes to sulfidize it.

[0038] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 26%.

[0039] Step 4: Add pH adjuster (HCl or NaOH), 350g / t ethyl xanthate and 60g / t pine oil to the floatable slurry in sequence, adjust the slurry to pH=6.5, and carry out flotation to obtain a copper concentrate recovery rate of 95.6%.

[0040] Example 2

[0041] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0042] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 2.34%, Fe 5.56%, CaO 18.70%, and SiO 248.96%.

[0043] Step 1: Crush the cobalt oxide ore to a particle size ≤ 2 mm, then grind it until the -0.074 mm particle size accounts for 80% of the total mass, to obtain copper oxide ore powder;

[0044] Step 2: The ore powder is transported to the suspension roasting system, which mainly consists of a heating decomposition device, a regenerative sulfidation device, and a cooling device. Natural gas and air are introduced into the combustion station at the bottom of the heating decomposition device for heating and combustion, preheating and dehydrating the ore powder for 8 minutes at a temperature of 90°C. Under negative pressure, the ore powder enters the regenerative sulfidation device from the top of the heating decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device, and the ore powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, at an amount of 1.15 times the amount required to completely react with CuO in the ore powder. The ore powder is roasted at a temperature of 450°C for 40 minutes to sulfidize it.

[0045] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 26%.

[0046] Step 4: Add pH adjuster (HCl or NaOH), 350g / t ethyl xanthate and 60g / t pine oil to the floatable slurry in sequence, adjust the slurry to pH=6.5, and carry out flotation to obtain a copper concentrate recovery rate of 95.8%.

[0047] Example 3

[0048] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0049] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 3.31%, Fe 4.69%, CaO 8.12%, and SiO2 0.23%.

[0050] Step 1: Crush the cobalt oxide ore to a particle size ≤ 2 mm, and then grind it until the particle size of -0.074 mm accounts for 80% of the total mass, to obtain copper oxide ore powder.

[0051] Step 2: The mineral powder is transported to the suspension roasting system, which mainly consists of a heating decomposition device, a regenerative sulfidation device, and a cooling device. Natural gas and air are introduced into the combustion station at the bottom of the heating decomposition device for heating and combustion, preheating and dehydrating the mineral powder for 10 minutes at a temperature of 90°C. Under negative pressure, the mineral powder enters the regenerative sulfidation device from the top of the heating decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device, and the mineral powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, at an amount of 1.2 times the amount required to completely react with CuO in the mineral powder. The mixture is roasted at 550°C for 45 minutes to sulfidize the mineral powder.

[0052] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 28%.

[0053] Step 4: Add pH adjuster (HCl or NaOH), 400g / t ethyl xanthate and 65g / t pine oil to the floatable slurry in sequence, adjust the slurry to pH=6.5, and carry out flotation to obtain a copper concentrate recovery rate of 96.3%.

[0054] Example 4

[0055] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0056] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 0.88%, Fe 3.64%, CaO 15.67%, and SiO 251.60%.

[0057] Step 1: Crush the cobalt oxide ore to a particle size ≤ 2 mm, and then grind it until the particle size of -0.074 mm accounts for 80% of the total mass, to obtain copper oxide ore powder.

[0058] Step 2: The mineral powder is transported to the suspension roasting system, which mainly consists of a heating decomposition device, a regenerative sulfidation device, and a cooling device. Natural gas and air are introduced into the combustion station at the bottom of the heating decomposition device for heating and combustion, preheating and dehydrating the mineral powder for 10 minutes at a temperature of 100℃. Under negative pressure, the mineral powder enters the regenerative sulfidation device from the top of the heating decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device, and the mineral powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, at an amount of 1.2 times that will react completely with CuO in the mineral powder. The mineral powder is roasted at a temperature of 600℃ for 50 minutes to sulfidize it.

[0059] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 25%.

[0060] Step 4: Add pH adjuster (HCl or NaOH), 400g / t ethyl xanthate and 65g / t pine oil to the floatable slurry in sequence, adjust the slurry to pH=6.5, and carry out flotation to obtain a copper concentrate recovery rate of 94.2%.

[0061] Example 5

[0062] Similar to Example 1, except that in the roasting system, pyrite was used as the sulfiding agent for the copper oxide powder, the roasting temperature was 550°C, and after roasting, grinding and flotation were carried out to obtain a copper concentrate recovery rate of 94.7%.

[0063] Example 6

[0064] Similar to Example 1, except that pyrite was used as a sulfiding agent in the roasting system for copper oxide powder, and the roasting time was 45 minutes. After roasting, grinding and flotation were carried out to obtain a copper concentrate recovery rate of 95.6%.

[0065] Example 7

[0066] Similar to Example 3, except that pyrite was used as a sulfiding agent in the roasting system for copper oxide powder, and the roasting time was 60 minutes. After roasting, grinding and flotation were carried out to obtain a copper concentrate recovery rate of 96.4%.

[0067] Example 8

[0068] Similar to Example 4, except that the roasting temperature was 700℃, and after roasting, the amount of ethyl xanthate used in the grinding and flotation was 450g / t, and the amount of pine oil used was 70g / t, resulting in a copper concentrate recovery rate of 94.7%.

[0069] Comparative Example 1

[0070] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0071] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 1.44%, Fe 5.78%, CaO 10.41%, and SiO 263.12%.

[0072] Step 1: Crush the copper oxide ore to a particle size ≤ 2 mm, then grind it until the portion with a particle size of -0.074 mm accounts for 80% of the total mass, to obtain copper oxide ore powder.

[0073] Step 2: The ore powder is transported to the suspension roasting system, which mainly consists of a heating decomposition device, a regenerative sulfidation device, and a cooling device. Natural gas and air are introduced into the combustion station at the bottom of the heating decomposition device for heating and combustion, preheating and dehydrating the ore powder for 5 minutes at a temperature of 100℃. Under negative pressure, the ore powder enters the regenerative sulfidation device from the top of the heating decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device, and the ore powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, at an amount of 1.1 times that of CuO in the ore powder to react completely. The ore powder is roasted at a temperature of 280℃ for 30 minutes to sulfidize it.

[0074] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 26%.

[0075] Step 4: Add pH adjuster (HCl or NaOH), 350 g / t ethyl xanthate and 60 g / t pine oil to the floatable slurry in sequence, and carry out flotation to obtain a copper concentrate recovery rate of 89.66%.

[0076] Comparative Example 2

[0077] A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment is described in the process flow diagram below. Figure 1 The specific operation method is as follows:

[0078] The main components of the copper oxide ore in this embodiment, by mass percentage, are Cu 2.43%, Fe 4.89%, CaO 11.26%, and SiO 262.47%.

[0079] Step 1: Crush the copper oxide ore to a particle size ≤ 2 mm, then grind it until the portion with a particle size of -0.074 mm accounts for 80% of the total mass, to obtain copper oxide ore powder.

[0080] Step 2: The mineral powder is transported to the suspension roasting system, which mainly consists of a heating decomposition device, a regenerative sulfidation device, and a cooling device. Natural gas and air are introduced into the combustion station at the bottom of the heating decomposition device for heating and combustion, preheating and dehydrating the mineral powder for 5 minutes at a temperature of 100℃. Under negative pressure, the mineral powder enters the regenerative sulfidation device from the top of the heating decomposition device. Nitrogen and hydrogen are introduced from the bottom of the regenerative sulfidation device, and the mineral powder is in a suspended state under the action of the airflow. Sulfur is added from the top of the device, with the amount added being 1 times the amount needed to completely react with CuO in the mineral powder. The mineral powder is roasted at a temperature of 850℃ for 30 minutes to sulfidize it.

[0081] Step 3: After the reaction is complete, cool the product through a cooler to obtain the roasted product. Grind the roasted product until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry. Adjust the slurry concentration to 26%.

[0082] Step 4: Add pH adjuster (HCl or NaOH), 350 g / t ethyl xanthate and 60 g / t pine oil to the floatable slurry in sequence, and carry out flotation to obtain a copper concentrate recovery rate of 87.14%.

Claims

1. A method for flotation separation of copper oxide ore after sulfidation roasting pretreatment, characterized in that, The specific steps are as follows: Step 1: Crush the copper oxide ore to a particle size ≤2mm, then grind it until the -0.074mm particle size portion accounts for 70~90% of the total mass, to obtain copper oxide ore powder; Step 2: The copper oxide ore powder is transported to the suspension roasting system for suspension roasting; The suspension roasting system includes a heating decomposition device, a heat storage vulcanization device, and a cooling device; The suspension roasting process is as follows: the copper oxide ore powder is preheated and dehydrated in a heating decomposition device; under negative pressure, the ore powder enters a regenerative sulfidation device from the top of the heating decomposition device, and nitrogen and hydrogen are introduced into the bottom of the regenerative sulfidation device. The ore powder is in a suspended state under the action of the airflow. A sulfiding agent is added from the top of the regenerative sulfidation device, and the ore powder is sulfided at a temperature of 300~550℃. The reaction equations involved in the sulfidation process are as follows: Cu2CO3(OH)2→2CuO+H2O(g)+CO2(g) (1) 2CuO + 2S → Cu2S + SO2(g) (2) 2CuO+2FeS2→Cu2S+2FeS+SO2(g) (3); Step 3: After the reaction in Step 2 is completed, the product is cooled by a cooler to obtain a roasted product; the roasted product is ground until the particle size of -0.074 mm accounts for ≥90% of the total mass to obtain a floatable slurry; Step 4: Add pH adjuster, collector and frother to the floatable slurry in sequence for flotation to obtain copper concentrate; The copper oxide ore described in step 1 contains 0.5% to 5% Cu by mass percentage; The amount of sulfiding agent added in step 2 is 1.1 to 1.2 times the theoretical amount required for the complete reaction of sulfur in the sulfiding agent with copper oxide in the mineral powder.

2. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The preheating and dehydration process described in step 2 involves introducing natural gas and air into the heating and decomposition device for heating and combustion, with a preheating time of 5-10 minutes and a preheating temperature of 80-100°C.

3. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The sulfiding agent mentioned in step 2 includes one of sulfur and pyrite.

4. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The residence time of the copper oxide powder in the regenerative sulfidation device in step 2 is 30-65 minutes.

5. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The concentration of the floatable slurry mentioned in step 3 is 25%~30%.

6. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The pH adjuster mentioned in step 4 is HCl or NaOH, and the slurry is adjusted to pH=6.5; the collector is ethyl xanthate, and the dosage is 300-600g / t; the foaming agent is pine oil, and the dosage is 50-80g / t.

7. The method for flotation separation of copper oxide ore after sulfidation roasting pretreatment according to claim 1, characterized in that, The copper recovery rate of the copper concentrate is ≥90%.

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