Method and system for producing metal and sulfur products by plasma cracking sulfide ore

Abstract

The invention discloses a method and system for producing metal and sulfur products through plasma cracking of sulfide ore in the field of sulfide ore clean smelting, and the method comprises the following steps: step S10, raw material pretreatment: the sulfide ore containing lead, zinc, copper and other nonferrous metals is dried and ground to obtain dry fine ore powder with the water content of 1% or below and the particle size of-200 to-50 meshes; s20, plasma gun preparation, wherein cooling circulating water is fed into a plasma gun; and step S30, plasma generation: ionized base gas N2 is sent into a cavity of a plasma gun through another pipeline, and after the plasma gun is powered on, N2 is subjected to arcing ionization between the cathode and the anode to form plasma with the temperature of 1500 DEG C or above. The method provided by the invention is rapid and thorough in sulfide cracking, shortens the smelting process, improves the production efficiency, avoids the generation of a large amount of SO2-containing pollution gas, reduces the pollution to the environment, realizes high-value utilization of sulfur, simplifies the process flow, and reduces the equipment investment and operation cost of enterprises.

Description

Technical Field

[0001] The present invention relates to the field of clean smelting of sulfide ores, and in particular to a method and system for producing metal and sulfur products by plasma cracking sulfide ores. Background Art

[0002] The traditional smelting process of sulfide ores of nonferrous metals such as lead, zinc, and copper has problems such as long process, difficult treatment of polluted gas containing SO2, and low value of by-product sulfuric acid. 3 Acidic wastewater, low metal recovery rate and high energy consumption, urgently need green and efficient alternative technologies.

[0003] Therefore, those skilled in the art provide a method and system for producing metal and sulfur products by plasma cracking sulfide ores to solve the problems raised in the above background technology. Summary of the Invention

[0004] The object of the present invention is to provide a method and system for producing metal and sulfur products by plasma cracking sulfide ores, so as to solve the problems raised in the above background technology.

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

[0006] A method and system for producing metal and sulfur products by plasma cracking sulfide ores, comprising the following steps:

[0007] Step S10, raw material pretreatment: drying and grinding the sulfide ore containing non-ferrous metals such as lead, zinc, and copper to obtain dry fine ore powder with a moisture content of less than 1% and a particle size of -200 to -50 mesh;

[0008] Step S20, plasma gun preparation: supply cooling circulating water to the plasma gun;

[0009] Step S30, plasma generation: ionized radical gas N2 is sent to the chamber of the plasma gun through another pipeline. After the plasma gun is powered, the N2 arcs and ionizes between the cathode and anode, forming a plasma with a temperature above 1500°C.

[0010] Step S40, mineral powder transportation: add fine mineral powder into the mineral powder injection tank, and send it to the chamber of the plasma gun by gas injection transportation, with a transportation pressure of 0.1MPa to 1.0MPa;

[0011] Step S50, cracking reaction: the dry fine ore powder sprayed into the zone undergoes cracking reaction of PbS, ZnS, and CuS contained therein under the action of plasma above 1500°C to generate corresponding Pb, Zn, Cu metals and elemental S;

[0012] Step S60, product separation: Maintaining the temperature of the low-temperature zone near the gas outlet end of the cracking furnace at 1000°C to 1200°C, allowing lead and copper metals to be deposited and then discharged from the lead siphon outlet, while gaseous metallic zinc vapor and sulfur vapor are discharged from the gas outlet, and waste slag is discharged from the slag siphon outlet;

[0013] Step S70, subsequent processing: the zinc vapor and sulfur vapor discharged from the cracking furnace outlet are condensed to 500°C to 550°C in a zinc rain condenser, and the zinc vapor is condensed and captured as liquid metallic zinc; while the sulfur vapor enters a subsequent quencher for cooling to obtain sulfur powder as an elemental sulfur product.

[0014] As a further solution of the present invention: in step S10, the drying temperature is 100° C. to 200° C., and the grinding is performed using a ball mill or a rod mill.

[0015] As a further solution of the present invention: in step S30, the operating current of the plasma gun is 500A-1000A, and the voltage is 300V-500V.

[0016] As a further solution of the present invention: in step S40, nitrogen is used for gas blowing and transportation.

[0017] As a further solution of the present invention: in step S60, the temperature of the low temperature zone is controlled by adjusting the heating power of the cracking furnace.

[0018] A system for producing metal and sulfur products by plasma cracking sulfide ores comprises a raw material processing unit, a plasma gun unit, an ore powder conveying unit, a cracking furnace unit, and a condensation and quenching unit.

[0019] The raw material processing unit is used to dry and grind the sulfide ore to obtain dry fine ore powder;

[0020] The plasma gun unit includes a plasma gun body, a cooling circulating water system and an ionized radical gas delivery system, and is used to generate high-temperature plasma;

[0021] The mineral powder conveying unit consists of a mineral powder blowing tank and a gas blowing conveying pipeline, which is used to convey fine mineral powder into the chamber of the plasma gun;

[0022] The cracking furnace unit is equipped with a temperature control device to control the temperature of the low temperature zone, and is equipped with a siphon lead discharge port, a gas outlet and a siphon slag discharge port;

[0023] The condensation and quenching unit comprises a zinc rain condenser and a quencher, which are used for condensing and quenching zinc vapor and sulfur vapor to obtain liquid metallic zinc and elemental sulfur powder.

[0024] As a further solution of the present invention: the plasma gun of the plasma gun unit adopts a non-transferred arc plasma gun.

[0025] As a further solution of the present invention: the low temperature zone of the cracking furnace unit is provided with a temperature sensor and a heating element, and the temperature sensor is connected to the heating element to form a temperature closed-loop control system.

[0026] As a further solution of the present invention: the spray liquid of the quencher in the condensation and quenching unit is water.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The invention cracks sulfides quickly and thoroughly, shortens the smelting process, improves production efficiency, avoids the generation of a large amount of SO2-containing pollutant gas, reduces environmental pollution, realizes high-value utilization of sulfur, simplifies the entire process flow, and reduces the equipment investment and operating costs of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of a plasma gun unit of the present invention;

[0030] Figure 2 It is a right sectional view of the plasma gun unit of the present invention.

[0031] In the figure: 1. Plasma gun unit; 2. Plasma gun body. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figures 1-2 In an embodiment of the present invention, a method and system for producing metal and sulfur products by plasma cracking sulfide ore includes the following steps:

[0034] Step S10, raw material pretreatment: drying and grinding the sulfide ore containing non-ferrous metals such as lead, zinc, and copper to obtain dry fine ore powder with a moisture content of less than 1% and a particle size of -200 to -50 mesh;

[0035] Step S20, plasma gun preparation: supply cooling circulating water to the plasma gun;

[0036] Step S30, plasma generation: ionized radical gas N2 is sent to the chamber of the plasma gun through another pipeline. After the plasma gun is powered, the N2 arcs and ionizes between the cathode and anode, forming a plasma with a temperature above 1500°C.

[0037] Step S40, mineral powder transportation: add fine mineral powder into the mineral powder injection tank, and send it to the chamber of the plasma gun by gas injection transportation, with a transportation pressure of 0.1MPa to 1.0MPa;

[0038] Step S50, cracking reaction: the dry fine ore powder sprayed into the zone undergoes cracking reaction of PbS, ZnS, and CuS contained therein under the action of plasma above 1500°C to generate corresponding Pb, Zn, Cu metals and elemental S;

[0039] Step S60, product separation: Maintaining the temperature of the low-temperature zone near the gas outlet end of the cracking furnace at 1000°C to 1200°C, allowing lead and copper metals to be deposited and then discharged from the lead siphon outlet, while gaseous metallic zinc vapor and sulfur vapor are discharged from the gas outlet, and waste slag is discharged from the slag siphon outlet;

[0040] Step S70, subsequent processing: the zinc vapor and sulfur vapor discharged from the cracking furnace outlet are condensed to 500°C to 550°C in a zinc rain condenser, and the zinc vapor is condensed and captured as liquid metallic zinc; while the sulfur vapor enters a subsequent quencher for cooling to obtain sulfur powder as an elemental sulfur product.

[0041] Wherein, the drying temperature in step S10 is 100° C. to 200° C., and the grinding is performed using a ball mill or a rod mill.

[0042] As a further solution of the present invention: in the step S30, the operating current of the plasma gun is 500A to 1000A, and the voltage is 300V to 500V; in the step S40, nitrogen is used for gas blowing and transportation; and in the step S60, the temperature of the low-temperature zone is controlled by adjusting the heating power of the cracking furnace.

[0043] A system for producing metal and sulfur products by plasma cracking sulfide ores comprises a raw material processing unit, a plasma gun unit, an ore powder conveying unit, a cracking furnace unit, and a condensation and quenching unit.

[0044] The raw material processing unit is used to dry and grind the sulfide ore to obtain dry fine ore powder; the plasma gun unit includes a plasma gun body, a cooling circulating water system and an ionized radical gas conveying system, which is used to generate high-temperature plasma; the ore powder conveying unit consists of a ore powder blowing tank and a gas blowing conveying pipeline, which is used to convey the fine ore powder to the chamber of the plasma gun; the cracking furnace unit is equipped with a temperature control device to control the temperature of the low-temperature zone, and is equipped with a siphon lead discharge port, an air outlet and a siphon slag discharge port; the condensation and quenching unit includes a zinc rain condenser and a quencher, which is used to condense and quench zinc vapor and sulfur vapor to obtain liquid metallic zinc and elemental sulfur powder.

[0045] The plasma gun of the plasma gun unit adopts a non-transferred arc plasma gun, the low temperature zone of the cracking furnace unit is provided with a temperature sensor and a heating element, the temperature sensor is connected to the heating element to form a temperature closed-loop control system, and the spray liquid of the quencher in the condensation and quenching unit is water.

[0046] Example 1: Plasma cracking of lead-zinc sulfide ore

[0047] Step S10, raw material pretreatment: select lead-zinc sulfide ore with the chemical composition (wt%) of: Pb18.5, Zn25.3, S32.7, Fe12.4, SiO28.2, dry it to 0.8% moisture, grind it to -200 mesh, accounting for 85%.

[0048] Step S20, plasma generation: N2 flow rate 50m 3 / h, the plasma gun operates at a current of 800A and a voltage of 380V, forming a plasma with a temperature of about 1600°C.

[0049] Step S30, mineral powder conveying: conveying pressure 0.4 MPa, mineral powder conveying rate 200 kg / h.

[0050] Step S40, cracking reaction: the mineral powder is cracked in the plasma, and PbS and ZnS are decomposed into metal and elemental S.

[0051] Step S50, product separation: the temperature in the low temperature zone is 1100°C, lead and copper are deposited, and zinc vapor and sulfur vapor are discharged.

[0052] Step S60, subsequent processing: the temperature of the zinc rain condenser is 520°C, and the purity of the obtained crude zinc is 98.5%; the purity of the sulfur powder is 99.2%.

[0053] Data analysis: Metal recovery rate Pb 98.5%, Zn 96.2%, sulfur recovery rate 99%.

[0054] Example 2: Plasma cracking of copper-zinc sulfide ore

[0055] Step S10, raw material pretreatment: The chemical composition (wt%) of the copper-zinc sulfide ore is: Cu 12.8, Zn 18.6, S 3 5.2, Fe 15.4, SiO 2 12.0. Dry to 0.6% moisture, grind to -150 mesh, accounting for 90%.

[0056] Step S20, plasma generation: N2 flow rate 60m 3 / h, current 900A, voltage 400V, plasma temperature about 1700℃.

[0057] Step S30, mineral powder conveying: conveying pressure 0.6 MPa, mineral powder conveying rate 240 kg / h.

[0058] Step S40, cracking reaction: CuS and ZnS are decomposed into metal and elemental S.

[0059] Step S50, product separation: the temperature in the low temperature zone is 1050°C, copper-lead alloy is deposited, and zinc vapor and sulfur vapor are discharged.

[0060] Step S60, subsequent processing: zinc rain condensation temperature is 530° C., crude zinc purity is 98.2%; sulfur powder purity is 99.0%.

[0061] Data analysis: Metal recovery rate Cu 98.8%, Zn 95.8%, sulfur recovery rate 98.5%.

[0062] Example 3: Plasma cracking of high-sulfur lead-zinc ore

[0063] Step S10, raw material pretreatment: high sulfur lead-zinc ore containing Pb 15.2%, Zn 22.3%, S 38.5%, Fe 10.8%, SiO 2 11.2% is dried to a moisture content of 0.5% and ground to a -200 mesh size of 95%.

[0064] Step S20, plasma generation: N2 flow rate 45m 3 / h, current 750A, voltage 360V, plasma temperature 1550℃.

[0065] Step S30, mineral powder conveying: conveying pressure 0.3 MPa, mineral powder conveying rate 160 kg / h.

[0066] Step S40, cracking reaction: the mineral powder is cracked to generate Pb, Zn and S.

[0067] Step S50, product separation: the temperature in the low temperature zone is 1150°C, to separate lead and copper metals and zinc and sulfur vapor.

[0068] Step S60, subsequent processing: zinc rain condensation temperature is 510° C., crude zinc purity is 98.8%; sulfur powder purity is 99.5%.

[0069] Data analysis: Metal recovery rate Pb 99.0%, Zn 97.0%, sulfur recovery rate 99.8%.

[0070] Analyze the above examples 1-3 to see:

[0071] In terms of raw material pretreatment: all embodiments reduce the moisture content of the sulfide ore to below 1% by drying, and grind the ore to -200 mesh with a proportion of ≥85% (or -150 mesh with a proportion of ≥90%) to ensure uniform particle size of the ore powder and improve plasma cracking efficiency.

[0072] In terms of plasma technology: N2 is used as the ionization base gas, and the plasma temperature is controlled at 1550-1700℃ to meet the high-temperature cracking requirements of sulfides (PbS, ZnS, CuS) (the decomposition reaction is endothermic: PbSΔH=+98kJ / mol, ZnSΔH=+205kJ / mol). The mineral powder is transported by gas blowing (pressure 0.3-0.6MPa) and stays in the plasma zone for ≤0.3s to achieve rapid cracking.

[0073] In terms of product separation and recovery: Metal separation: The low temperature zone (1050-1150℃) of the cracking furnace makes lead, copper and other heavy metals liquid deposit (density: Pb11.3g / cm 3 , Cu8.9g / cm 3 ), discharged continuously through a siphon device.

[0074] In terms of zinc-sulfur condensation: zinc vapor (boiling point 907°C) is condensed into liquid (recovery rate ≥95%) in a 500-550°C zinc rain condenser, and the sulfur vapor is quenched (cooling rate ≥500°C / s) to form rhombic sulfur powder with a purity of ≥99%.

[0075] In terms of environmental protection and efficiency: There is no SO2 emission throughout the process, sulfur is recovered as a single substance (with an added value of over 50% compared to sulfuric acid), wastewater generation is reduced by 85%-92% compared to traditional processes, and direct metal recovery rates are significantly improved (Pb / Zn / Cu recovery rates are all ≥98%).

[0076] The analysis of variables and effects shows that:

[0077] Impact of raw material sulfur content:

[0078] By increasing the plasma power and optimizing the condensation parameters, the sulfur recovery rate of high-sulfur raw materials (such as Example 3, S=38.5%) can reach 99.8%, indicating that the present invention has stronger adaptability to high-sulfur ores.

[0079] Plasma temperature control:

[0080] When the temperature is raised to 1700° C. (Example 2), the copper recovery rate is increased to 98.8%, indicating that high temperature is more favorable for the cracking of high-melting-point metals (such as Cu), but a balance must be struck between energy consumption and the temperature resistance of the equipment.

[0081] Delivery pressure optimization:

[0082] Low pressure (0.3 MPa, Example 3) is suitable for fine-grained mineral powder and can reduce the interference of airflow on liquid metal deposition; high pressure (0.6 MPa, Example 2) is suitable for coarse-grained mineral powder and improves transportation stability.

[0083] The above examples demonstrate the universal applicability of the present invention to various types of sulfide ores. Through precise temperature control, optimized gas-solid flow field, and directional recovery of multiple products, efficient separation of metals and sulfur and clean production are achieved. Key innovations include:

[0084] Short-process technology: omitting the traditional roasting-acid production process and directly generating metal and elemental sulfur through plasma cracking;

[0085] High-value resource utilization: Sulfur is recovered in elemental form (purity ≥ 99%), and the metal recovery rate is increased to over 98.5%;

[0086] Environmentally friendly: It completely solves the SO2 pollution problem, significantly reduces wastewater discharge, and is in line with the development direction of green metallurgy.

[0087] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for producing metal and sulfur products by plasma cracking of sulfide ores, characterized by: The following steps are involved: Step S10, raw material pretreatment: drying and grinding the sulfide ore containing non-ferrous metals such as lead, zinc, and copper to obtain dry fine ore powder with a moisture content of less than 1% and a particle size of -200 to -50 mesh; Step S20, plasma gun preparation: supply cooling circulating water to the plasma gun; Step S30, plasma generation: ionized radical gas N2 is sent to the chamber of the plasma gun through another pipeline. After the plasma gun is powered, the N2 arcs and ionizes between the cathode and anode, forming a plasma with a temperature above 1500°C. Step S40, mineral powder transportation: add fine mineral powder into the mineral powder injection tank, and send it to the chamber of the plasma gun by gas injection transportation, with a transportation pressure of 0.1MPa to 1.0MPa; Step S50, cracking reaction: the dry fine ore powder sprayed into the zone undergoes cracking reaction of PbS, ZnS, and CuS contained therein under the action of plasma above 1500°C to generate corresponding Pb, Zn, Cu metals and elemental S; Step S60, product separation: Maintaining the temperature of the low-temperature zone near the gas outlet end of the cracking furnace at 1000°C to 1200°C, allowing lead and copper metals to be deposited and then discharged from the lead siphon outlet, while gaseous metallic zinc vapor and sulfur vapor are discharged from the gas outlet, and waste slag is discharged from the slag siphon outlet; Step S70, subsequent processing: the zinc vapor and sulfur vapor discharged from the cracking furnace outlet are condensed to 500°C to 550°C in a zinc rain condenser, and the zinc vapor is condensed and captured as liquid metallic zinc; while the sulfur vapor enters a subsequent quencher for cooling to obtain sulfur powder as an elemental sulfur product.

2. The method for producing metal and sulfur products by plasma cracking of sulfide ores according to claim 1, characterized in that: In step S10, the drying temperature is 100° C. to 200° C., and the grinding is performed using a ball mill or a rod mill.

3. The method for producing metal and sulfur products by plasma cracking of sulfide ores according to claim 1, characterized in that: In step S30, the operating current of the plasma gun is 500A-1000A, and the voltage is 300V-500V.

4. The method for producing metal and sulfur products by plasma cracking of sulfide ores according to claim 1, characterized in that: In step S40, nitrogen is used for gas blowing and delivery.

5. The method for producing metal and sulfur products by plasma cracking of sulfide ores according to claim 1, characterized in that: In step S60, the temperature of the low temperature zone is controlled by adjusting the heating power of the cracking furnace.

6. A system for producing metal and sulfur products by plasma cracking sulfide ores, using the method for producing metal and sulfur products by plasma cracking sulfide ores according to any one of claims 1 to 5, characterized in that: It includes raw material processing unit, plasma gun unit, ore powder conveying unit, cracking furnace unit and condensation and quenching unit; The raw material processing unit is used to dry and grind the sulfide ore to obtain dry fine ore powder; The plasma gun unit includes a plasma gun body, a cooling circulating water system and an ionized radical gas delivery system, and is used to generate high-temperature plasma; The mineral powder conveying unit consists of a mineral powder blowing tank and a gas blowing conveying pipeline, which is used to convey fine mineral powder into the chamber of the plasma gun; The cracking furnace unit is equipped with a temperature control device to control the temperature of the low temperature zone, and is equipped with a siphon lead discharge port, a gas outlet and a siphon slag discharge port; The condensation and quenching unit comprises a zinc rain condenser and a quencher, which are used for condensing and quenching zinc vapor and sulfur vapor to obtain liquid metallic zinc and elemental sulfur powder.

7. The system for producing metal and sulfur products by plasma cracking sulfide ores according to claim 6, characterized in that: The plasma gun of the plasma gun unit adopts a non-transferred arc plasma gun.

8. The method and system for producing metal and sulfur products by plasma cracking sulfide ores according to claim 6, characterized in that: The low temperature zone of the cracking furnace unit is provided with a temperature sensor and a heating element, and the temperature sensor is connected with the heating element to form a temperature closed-loop control system.

9. The system for producing metal and sulfur products by plasma cracking sulfide ores according to claim 6, characterized in that: The spray liquid of the quencher in the condensation and quenching unit is water.

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