Method and device for recovering sulfur and valuable metal based on plasma cracking sulfide ore

Abstract

The invention discloses a method and a device for recovering sulfur and valuable metals based on plasma cracking sulfide ore in the field of sulfide ore resource recycling, and the method comprises the following steps: step 1) crushing the sulfide ore to 200-400 meshes through a raw material pretreatment system, and premixing the crushed sulfide ore with a carbon source according to a C / S molar ratio of 1.2-1.5; and step 2), feeding the premixed raw materials into a plasma reactor, reacting in a high-temperature field (the temperature of a main discharge region is 8000 + / -500K) generated by a multi-stage arc, controlling the reaction retention time to be 0.5-1.2 seconds, and controlling the high-temperature region to maintain cracking and the medium-temperature region to promote CS2 synthesis through a sectional temperature control module. Compared with a traditional method, the recovery rate is remarkably improved, and the utilization efficiency of sulfide ore resources is greatly improved. And meanwhile, by utilizing the advantage of instantaneous heating of the plasma, the energy consumption is further reduced, the production cost is reduced, SO2 emission is thoroughly avoided, the problem of environmental pollution of traditional pyrogenic process smelting is solved from the source, and remarkable environmental protection benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the field of recovery and utilization of sulfide ore resources, and specifically to a method and device for recovering sulfur and valuable metals based on plasma cracking of sulfide ore. Background Art

[0002] In the field of sulfide ore treatment, traditional pyrometallurgy generates a large amount of SO2 gas when treating sulfide ore. If these gases are directly discharged, they will seriously pollute the atmospheric environment and cause environmental problems such as acid rain. At the same time, pyrometallurgy usually requires a complex and expensive flue gas treatment system, which not only increases production costs but also makes the process flow more complex. Relatively, although the hydrometallurgical leaching technology avoids SO2 emissions to a certain extent, it has the drawback of a long reaction cycle. A long reaction means low production efficiency and low equipment utilization rate. In addition, a large amount of auxiliary materials are consumed during the hydrometallurgical leaching process, further increasing production costs and limiting the large-scale application of this technology. At the same time, in the existing cracking technology for treating symbiotic ores, the metal separation effect is not ideal. In symbiotic ores, multiple metals are associated with each other, and it is difficult for the existing technology to completely separate them, resulting in a low recovery rate of valuable metals and wasting resources. Moreover, the current form of sulfur element recovery is relatively single, mostly recovered in the form of sulfuric acid or elemental sulfur. This single recovery method cannot fully utilize the value of sulfur elements and also limits the comprehensive utilization efficiency of sulfide ore resources.

[0003] Therefore, those skilled in the art have provided a method and device for recovering sulfur and valuable metals based on plasma cracking of sulfide ore to solve the problems raised in the above background art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for recovering sulfur and valuable metals based on plasma cracking of sulfide ore to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method and device for recovering sulfur and valuable metals based on plasma cracking of sulfide ore, including the following steps:

[0007] Step 1): Crush the sulfide ore to 200 - 400 mesh through a raw material pretreatment system and premix it with a carbon source according to a C / S molar ratio of 1.2 - 1.5;

[0008] Step 2): Feed the premixed raw materials into a plasma reactor, and carry out a reaction under a high-temperature field generated by a multi-stage electric arc (the temperature in the main discharge area is 8000 ± 500K). The reaction residence time is 0.5 - 1.2 seconds. Control the high-temperature zone to maintain cracking and the medium-temperature zone to promote CS2 synthesis through a segmented temperature control module;

[0009] Step 3): The reaction product passes through a gradient condensation system successively. In the first-stage quench tower (200 - 300 °C), low-boiling metals such as Zn and Pb are trapped, and in the second-stage cryogenic device (-20 °C), CS2 is liquefied and collected.

[0010] Step 4): The remaining molten metal is sent into a molten metal separation tank. Valuable metals are separated by density difference stratification and an electromagnetic separation module. Due to density difference stratification, high-density metals such as Cu and Fe sink, while As and Sb float.

[0011] As a further scheme of the present invention: The carbon source is biomass charcoal or graphite powder.

[0012] As a still further scheme of the present invention: The method further includes that for metals with a boiling point lower than 1500 °C, they are collected by gas-phase trapping in the first-stage quench tower of the gradient condensation system; for metals with a boiling point higher than 1500 °C, they are separated by molten-state density stratification combined with electromagnetic separation in the molten metal separation tank.

[0013] A device for recovering sulfur and valuable metals based on the pyrolysis of sulfide ore by plasma includes a raw material pretreatment system, a plasma reactor, a gradient condensation system, and a molten metal separation tank.

[0014] The raw material pretreatment system is used to crush the sulfide ore and premix it with the carbon source.

[0015] The plasma reactor has a multi-stage arc design, a vortex intake structure, and a segmented temperature control module.

[0016] The vortex intake structure forms a swirling airflow through the vortex intake port, and cooperates with a flow controller to accurately control the gas input; the multi-stage arc design uses multi-stage arc electrodes (such as primary + secondary electrodes), which are energized by an arc power supply to generate a long-distance plasma arc; the segmented temperature control module adjusts the temperature of different regions of the reaction chamber through a segmented temperature control module (including a temperature sensor and a heating / cooling unit); the reaction chamber is internally provided with an insulating lining to ensure the stability of the arc and its resistance to high temperatures, and cooperates with the swirling airflow to achieve an efficient reaction.

[0017] The gradient condensation system includes a first-stage quench tower and a second-stage cryogenic device.

[0018] The molten metal separation tank adopts a density difference stratification design and is equipped with an electromagnetic separation module.

[0019] As a still further scheme of the present invention: The axial direction of the plasma reactor has a temperature gradient field, the high-temperature zone is maintained above 3000 °C, and the medium-temperature zone is controlled at 800 - 1200 °C.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The recovery rate of the present invention is significantly improved compared with the traditional method, greatly improving the utilization efficiency of sulfide ore resources. Taking advantage of the instantaneous heating of plasma, it reduces energy consumption, lowers production costs, completely avoids SO2 emissions, and solves the environmental pollution problem of traditional pyrometallurgy from the source, with significant environmental benefits. Brief Description of the Drawings

[0022] Figure 1 It is a composition diagram of the plasma reactor in the invention. Detailed Embodiments

[0023] Next, in combination with the embodiments of the present invention and the accompanying drawings, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0024] In the embodiments of the present invention, a method and device for recovering sulfur and valuable metals based on the pyrolysis of sulfide ore by plasma include the following steps:

[0025] Step 1): Crush the sulfide ore to 200 - 400 mesh through the raw material pretreatment system, and premix it with the carbon source according to a C / S molar ratio of 1.2 - 1.5;

[0026] Step 2): Feed the premixed raw materials into the plasma reactor, and carry out the reaction under the high-temperature field generated by multi-stage arcs (the temperature in the main discharge area is 8000 ± 500K). The reaction residence time is 0.5 - 1.2 seconds, and the high-temperature zone is controlled to maintain pyrolysis and the medium-temperature zone is promoted to synthesize CS2 through the segmented temperature control module;

[0027] Step 3): The reaction products pass through the gradient condensation system in turn. The low-boiling metals such as Zn and Pb are captured in the first-stage quench tower (200 - 300°C), and CS2 is liquefied and collected in the second-stage deep cooling device (-20°C);

[0028] Step 4): Feed the remaining molten metal into the molten metal separation tank, and separate the valuable metals by using density difference stratification and the electromagnetic separation module. The high-density metals such as Cu and Fe sink due to density difference stratification, and the low-density metals such as As and Sb float.

[0029] Among them, the carbon source is biomass charcoal or graphite powder.

[0030] Among them, the method further includes collecting metals with a boiling point lower than 1500°C by means of gas-phase trapping in the first-stage quench tower of the gradient condensation system; for metals with a boiling point higher than 1500°C, separating them in the molten metal separation tank by means of density stratification in the molten state combined with electromagnetic separation.

[0031] An apparatus for recovering sulfur and valuable metals based on the pyrolysis of sulfide ore by plasma includes a raw material pretreatment system, a plasma reactor, a gradient condensation system, and a molten metal separation tank.

[0032] The raw material pretreatment system is used to crush the sulfide ore and premix it with a carbon source;

[0033] As Figure 1 shown, the plasma reactor has a multi-stage arc design, a vortex intake structure, and a segmented temperature control module;

[0034] The vortex intake structure forms a rotating gas flow through the vortex intake port, and precisely controls the gas input in cooperation with the flow controller; the multi-stage arc design uses multi-stage arc electrodes (such as primary + secondary electrodes), which are energized by the arc power supply to generate a long-distance plasma arc; the segmented temperature control module adjusts the temperature of different regions of the reaction chamber through the segmented temperature control module (including temperature sensors and heating / cooling units); an insulating lining is installed inside the reaction chamber to ensure the stability of the arc and withstand high temperatures, and cooperate with the vortex gas flow to achieve efficient reaction;

[0035] The gradient condensation system includes a first-stage quench tower and a second-stage deep cooling device;

[0036] The molten metal separation tank adopts a density difference stratification design and is equipped with an electromagnetic separation module.

[0037] Among them, the axial direction of the plasma reactor has a temperature gradient field, the high-temperature zone is maintained above 3000°C, and the medium-temperature zone is controlled at 800 - 1200°C.

[0038] Example 1

[0039] A certain amount of copper sulfide ore was selected and crushed to 200 mesh. According to the C / S molar ratio of 1.2, the copper sulfide ore was premixed with biochar. The premixed raw materials were fed into a plasma reactor, and a multi-stage arc was started to maintain the temperature in the main discharge area at 8000K. Through a vortex gas inlet structure, the reaction residence time was ensured to be 0.5 seconds. During the reaction process, a segmented temperature control module was used to keep the pyrolysis reaction in the high-temperature zone and promote the synthesis of CS2 in the medium-temperature zone. The reaction gas and products were successively introduced into a gradient condensation system. Low-boiling metals such as Zn and Pb were trapped in the first-stage quench tower (200°C), and liquefied CS2 was collected in the second-stage cryogenic device (-20°C). Finally, the remaining molten metal was fed into a molten metal separation tank, and high-purity Cu and other valuable metals were successfully separated by density difference stratification and an electromagnetic separation module. After testing, the sulfur recovery rate reached 99.2%, the comprehensive metal recovery rate increased by 18 percentage points compared with the traditional method, and the energy consumption decreased by 42%.

[0040] Example 2

[0041] Another batch of sulfide ores with different compositions was selected and crushed to 400 mesh. After premixing it with graphite powder according to the C / S molar ratio of 1.5, it was fed into a plasma reactor. The multi-stage arc was adjusted to make the temperature in the main discharge area 7500K, and the reaction residence time was extended to 1.2 seconds. In the gradient condensation system, the temperature of the first-stage quench tower was set at 300°C, and the temperature of the second-stage cryogenic device was kept at -20°C. In the molten metal separation tank, the metal separation effect was further improved by optimizing the density difference stratification and electromagnetic separation parameters. The experimental results showed that the sulfur recovery rate reached 99.5%, the comprehensive metal recovery rate increased by 25 percentage points, and the energy consumption decreased by 38%.

[0042] Example 3

[0043] A complex symbiotic sulfide ore was selected, crushed to 300 mesh, and premixed with biochar according to the C / S molar ratio of 1.3. In the plasma reactor, the temperature in the main discharge area was controlled at 8500K, and the reaction residence time was 0.8 seconds. The gradient condensation system and the molten metal separation tank were operated according to the parameters of the above examples. Finally, the sulfur recovery rate reached 99.3%, the comprehensive metal recovery rate increased by 22 percentage points, and the energy consumption decreased by 40%.

[0044] Through the analysis of the above embodiments, it can be seen that the sulfur recovery rate can be increased to over 99%, which is significantly higher than the recovery rate of about 85% in the traditional method. The comprehensive metal recovery rate is increased by 15 - 30 percentage points, greatly improving the utilization efficiency of sulfide ore resources. Taking advantage of the instantaneous heating of the plasma, the energy consumption is reduced by 40%, reducing energy consumption and production costs. It completely avoids SO2 emissions, solves the environmental pollution problem of traditional pyrometallurgy from the source, and has significant environmental benefits. It can be seen that the method and device of the present invention can achieve efficient recovery of sulfur and valuable metals in the treatment of different types of sulfide ores, verifying its feasibility and stability.

[0045] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered by the protection scope of the present invention.

Claims

1. A method for recovering sulfur and valuable metals from sulfide ores by plasma pyrolysis, characterized in that: It includes the following steps: Step 1), crushing the sulfide ore to 200 - 400 mesh through a raw material pretreatment system, and premixing it with a carbon source at a C / S molar ratio of 1.2 - 1.5; Step 2), feeding the premixed raw materials into a plasma reactor, reacting under the high-temperature field (the temperature in the main discharge area is 8000 ± 500 K) generated by multi-stage arcs, with a reaction residence time of 0.5 - 1.2 seconds, and controlling the high-temperature zone to maintain cracking and the medium-temperature zone to promote CS2 synthesis through a segmented temperature control module; Step 3), the reaction products pass through a gradient condensation system in sequence, collecting low-boiling metals in the first-stage quench tower (200 - 300 °C), and liquefying and collecting CS2 in the second-stage cryogenic device (-20 °C); Step 4), feeding the remaining molten metal into a molten metal separation tank, and separating valuable metals by density difference stratification and an electromagnetic separation module.

2. The method for recovering sulfur and valuable metals based on the pyrolysis of sulfide ore by plasma according to claim 1, wherein: The carbon source is biomass carbon or graphite powder.

3. The method for recovering sulfur and valuable metals based on the pyrolysis of sulfide ores by plasma according to claim 1, wherein: The method further includes, for metals with a boiling point below 1500 °C, collecting them in the first-stage quench tower of the gradient condensation system by gas-phase capture; for metals with a boiling point above 1500 °C, separating them in the molten metal separation tank by a combination of molten density stratification and electromagnetic separation.

4. An apparatus for recovering sulfur and valuable metals by pyrolyzing sulfide ore based on plasma, applying the method for recovering sulfur and valuable metals by pyrolyzing sulfide ore based on plasma according to any one of claims 1-3, characterized in that: It includes a raw material pretreatment system, a plasma reactor, a gradient condensation system, and a molten metal separation tank. The raw material pretreatment system is used to crush the sulfide ore and premix it with the carbon source; The plasma reactor has a multi-stage arc design, a vortex intake structure, and a segmented temperature control module; The vortex intake structure forms a rotating air flow through the vortex intake port, and precisely controls the gas input in cooperation with a flow controller; the multi-stage arc design uses multi-stage arc electrodes, which are energized by an arc power supply to generate a long-distance plasma arc; the segmented temperature control module adjusts the temperature of different regions of the reaction chamber through the segmented temperature control module; the reaction chamber is equipped with an insulating lining to ensure the stability of the arc and its high-temperature resistance, and realizes an efficient reaction in cooperation with the vortex air flow; The gradient condensation system includes a first-stage quench tower and a second-stage cryogenic device; The molten metal separation tank adopts a density difference stratification design and is equipped with an electromagnetic separation module.

5. The device for recovering sulfur and valuable metals based on the pyrolysis of sulfide ores by plasma according to claim 4, characterized in that: The axial direction of the plasma reactor has a temperature gradient field, with the high-temperature zone maintained above 3000 °C and the medium-temperature zone controlled at 800 - 1200 °C.

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