Integrated furnace for suspension melting and reduction of mineral powder and method for treating mineral powder by using integrated furnace

Abstract

Disclosed are an integrated furnace for suspension melting and reduction of mineral powder and a method for treating mineral powder by using the integrated furnace. The integrated furnace for suspension melting and reduction of mineral powder comprises a vertical melting tower and a horizontal reduction furnace. The vertical melting tower sequentially comprises a secondary combustion chamber and a suspension melting zone from top to bottom; the secondary combustion chamber is provided with secondary combustion spray guns; and the suspension melting zone is provided with material spray guns, and the material spray guns are used for spraying oxygen-enriched air and mineral powder into the suspension melting zone. The horizontal reduction furnace sequentially comprises a reduction zone and a settling zone in the horizontal direction; a partition wall is provided between the reduction zone and the settling zone; the lower end of the partition wall extends into a slag layer of the horizontal reduction furnace; a gas outlet is formed in the upper end of the reduction zone and is connected to the lower end of the suspension melting zone; and the reduction zone is provided with reduction spray guns, and the reduction spray guns are used for spraying a reducing agent and combustion-supporting air.

Description

Ore powder suspension melting reduction integrated furnace and method for treating ore powder

[0001] Priority information

[0002] This application requests priority to the Chinese patent application filed with the State Intellectual Property Office of China on October 30, 2023, with patent application number 202311429462.0 and application name “Mineral powder suspension smelting reduction integrated furnace and method for treating mineral powder thereof”, and all the contents of which are incorporated by reference in this disclosure. Technical Field

[0003] The present application belongs to the technical field of metal smelting, and specifically relates to a mineral powder suspension melting and reduction integrated furnace and a method for processing the mineral powder. Background Art

[0004] Currently, there are two ways to perform melting reduction of solid materials. One way is to carry out melting and reduction in the same reaction zone, and the coal gas generated by melting reduction is used to supplement heat for melting and reduction through secondary combustion. Due to the low efficiency of radiation heat supplementation, most of the heat is enriched in the flue gas, resulting in high fuel consumption and large flue gas volume; the other way is to carry out melting and reduction in two separate furnaces (or different zones in the same furnace), first melt the mineral powder, and then send the molten mineral powder into the reduction furnace for reduction treatment. The coal gas generated by the reduction furnace is generally collected and treated separately through a coal gas collection system. This method requires a separate collection and treatment system to collect the coal gas. The system is complex, the coal gas sensible heat utilization rate is low (in order to avoid explosion, the coal gas needs to be rapidly cooled in the temperature range of 810-200°C), and there is still a risk of explosion (especially when the reduction furnace is operated under negative pressure).

[0005] Public content

[0006] The present disclosure aims to solve, at least to a certain extent, one of the technical problems in the related art. To this end, one purpose of the present disclosure is to propose a mineral powder suspension melting and reduction integrated furnace and a method for treating mineral powder. The mineral powder suspension melting and reduction integrated furnace completes the melting and reduction of mineral powder in the same device, and at the same time burns the coal gas generated by the reduction. The combustion releases heat to melt the mineral powder, thereby fully utilizing the calorific value of the coal gas, reducing the input of external heat sources, and reducing production costs. After the coal gas is utilized, the coal gas collection and processing system is saved, further reducing equipment costs.

[0007] In one aspect of the present disclosure, a mineral powder suspension melting and reduction integrated furnace is provided. According to an embodiment of the present disclosure, the mineral powder suspension melting and reduction integrated furnace includes:

[0008] A vertical melting tower, which comprises, from top to bottom, a secondary combustion chamber and a suspension melting zone, wherein the secondary combustion chamber is provided with a secondary combustion lance, and the suspension melting zone is provided with a material lance for injecting oxygen-enriched air and mineral powder into the suspension melting zone;

[0009] A horizontal reduction furnace, which includes a reduction zone and a sedimentation zone in sequence along the horizontal direction. A partition wall is provided between the reduction zone and the sedimentation zone, and the lower end of the partition wall extends into the slag layer of the horizontal reduction furnace. A gas outlet is provided at the upper end of the reduction zone, and the gas outlet is connected to the lower end of the suspended melting zone. The reduction zone is provided with a reduction lance, and one end of the reduction lance extends into the slag layer of the reduction zone. The reduction lance is used to spray reducing agent and combustion-supporting air. The sedimentation zone is provided with a metal discharge port and a slag discharge port.

[0010] According to the above-mentioned embodiment of the present disclosure, the integrated furnace for suspended smelting and reduction of mineral powder includes a vertical melting tower and a horizontal reduction furnace. The vertical melting tower includes a secondary combustion chamber and a suspended melting zone in sequence from top to bottom. The horizontal reduction furnace includes a reduction zone and a sedimentation zone in sequence along the horizontal direction. The reduction zone is provided with a reduction lance. One end of the reduction lance extends into the slag layer in the reduction zone. The reduction lance is used to spray reducing agent and combustion-supporting air. The O2 in the combustion-supporting air and the reducing agent undergo an incomplete combustion reaction at the outlet of the reduction lance, releasing heat and stirring the liquid slag in the slag layer. The remaining reducing agent reduces the liquid slag in the slag layer. The heat from the combustion of the combustion-supporting air is used to maintain the temperature of the reduction zone. A partition wall is provided between the reduction zone and the settling zone, the lower end of which extends into the slag layer of the horizontal reduction furnace. After the slag reacts in the reduction zone, it enters the settling zone from the siphon port between the partition wall and the bottom of the horizontal reduction furnace. Metal is then deposited in the settling zone to form a molten metal. The settling zone is provided with a metal discharge port and a slag discharge port. The molten metal can be discharged from the metal discharge port, and the upper slag can be discharged from the slag discharge port. A gas outlet is provided at the upper end of the reduction zone of the horizontal reduction furnace, and the gas generated after the reduction reaction in the reduction zone is discharged from the gas outlet. Because a partition wall is provided between the reduction zone and the settling zone, the lower end of which extends into the slag layer of the horizontal reduction furnace, and therefore, the reduction zone and the settling zone form independent spaces, and the gas generated in the reduction zone is discharged through the gas outlet. The gas outlet is connected to the lower end of the suspension melting zone. Gas enters the zone from this outlet. A material injection lance is installed in the suspension melting zone, injecting oxygen-enriched air and mineral powder into the zone. The oxygen-enriched air reacts and burns with CO, H2, and other substances in the gas, releasing a large amount of heat. This maintains the zone's high temperature of 1500°C to 1600°C. Simultaneously, the gas, along with the gases produced by its reaction with oxygen, moves upward, creating an upward airflow in the zone. The mineral powder is suspended in this airflow and rapidly melts at this high temperature. The melted droplets collide, grow, and fall into the reduction zone of the horizontal reduction furnace, where they undergo reduction. As the droplets descend, they come into contact with the rising gas, exchanging heat and conducting pre-reduction, thereby accelerating the reduction process in the reduction zone. The unburned gas in the suspended melting zone enters the secondary combustion chamber, which is equipped with a secondary combustion spray gun. The oxygen sprayed by the secondary combustion spray gun is further burned with the unburned gas to completely eliminate the combustible components such as CO and H2, avoiding explosion during subsequent flue gas treatment.

[0011] Therefore, the integrated furnace for suspended smelting and reduction of mineral powder completes the melting and reduction of mineral powder in the same equipment, and burns the coal gas generated by the reduction at the same time. The combustion releases heat to melt the mineral powder, thereby making full use of the calorific value of the coal gas, reducing the input of external heat sources, and reducing production costs. After the coal gas is utilized, the coal gas collection and processing system is saved, further reducing the equipment investment cost.

[0012] In addition, the integrated ore powder suspension smelting reduction furnace according to the above embodiment of the present disclosure may also have the following additional technical features:

[0013] In some embodiments of the present disclosure, the gas outlet is provided at an upper end of the reduction zone away from the settling zone.

[0014] In some embodiments of the present disclosure, the sedimentation zones are respectively provided at both ends of the reduction zone along the horizontal direction.

[0015] In some embodiments of the present disclosure, the settling area is provided with a heating component and / or a smoke exhaust port, thereby maintaining the temperature of the settling area and / or exhausting the smoke in the settling area.

[0016] In some embodiments of the present disclosure, the lower end of the partition wall extends into the slag layer of the reduction zone to a depth of not less than 300 mm, thereby ensuring that the reduction zone and the settling zone form independent spaces.

[0017] In some embodiments of the present disclosure, the distance between the lower end of the partition wall and the bottom of the horizontal reduction furnace is 300 mm to 500 mm, thereby facilitating the flow of liquid slag from the reduction zone to the settling zone.

[0018] In some embodiments of the present disclosure, one end of the reduction lance extends into the slag layer to a depth of 200 mm to 300 mm, thereby facilitating improved reduction efficiency in the reduction zone.

[0019] In some embodiments of the present disclosure, a combustion lance is provided below the gas outlet for injecting fuel and combustion-supporting air, with one end of the combustion lance extending into the slag layer to a depth of 200 mm to 300 mm, thereby further melting unmelted mineral powder.

[0020] In some embodiments of the present disclosure, the bottom of the horizontal reduction furnace is divided into a first furnace bottom area and a second furnace bottom area along the horizontal direction. The first furnace bottom area is higher than the second furnace bottom area, and the partition wall is located above the second furnace bottom area. This facilitates metal collection.

[0021] In some embodiments of the present disclosure, the horizontal distance between the partition wall and the first furnace bottom zone is 500 mm to 1000 mm, thereby facilitating metal collection.

[0022] In some embodiments of the present disclosure, the reduction zone is provided with an auxiliary lance, one end of which extends into the slag layer in the second furnace bottom zone, and is used to spray sulfur or pulverized coal, thereby completing the sulfiding or carburizing operation.

[0023] In some embodiments of the present disclosure, the distance between one end of the auxiliary lance and the interface between the metal melt layer and the slag layer in the reduction zone is 150 mm to 250 mm, thereby completing the sulfiding or carburizing operation.

[0024] In some embodiments of the present disclosure, the angle between the auxiliary spray gun and the horizontal direction is 60 degrees to 75 degrees.

[0025] In some embodiments of the present disclosure, the ratio of the horizontal cross-sectional dimension of the secondary combustion chamber to the horizontal cross-sectional dimension of the suspension melting zone is (2-3):1. Thus, the carried-out mineral powder particles can be settled into the suspension zone, reducing the smoke rate.

[0026] In some embodiments of the present disclosure, the lower end of the secondary combustion chamber is contracted to form a neck section, and the angle between the sidewall of the neck section and the horizontal direction is 65 to 75 degrees. This can prevent dust accumulation on the inner sidewall of the neck section and reduce equipment failure rate.

[0027] In some embodiments of the present disclosure, one end of the secondary combustion lance is perpendicular to the side wall of the necked section and extends into the secondary combustion chamber, thereby enabling the coal gas to be fully burned.

[0028] In some embodiments of the present disclosure, the upper end of the secondary combustion chamber is connected to a waste heat boiler, thereby making full use of the heat of the exhaust flue gas.

[0029] In some embodiments of the present disclosure, the upper end of the secondary combustion chamber is connected to a mineral powder preheating device, thereby utilizing the heat of the exhaust flue gas to preheat the mineral powder, thereby reducing production costs.

[0030] In some embodiments of the present disclosure, a supplementary heat spray gun is provided below the suspension melting zone. The supplementary heat spray gun is located below the material spray gun, and one end of the supplementary heat spray gun extends into the suspension melting zone. The supplementary heat spray gun sprays the oxygen-enriched air, thereby supplementing heat for the smelting reduction.

[0031] In some embodiments of the present disclosure, the supplementary heat lance injects fuel and the oxygen-enriched air, thereby providing coal gas to the suspension melting zone and supplementing heat for melting reduction.

[0032] In another aspect of the present disclosure, a method for treating ore powder using the above-mentioned ore powder suspension smelting reduction integrated furnace is proposed. According to an embodiment of the present disclosure, the method includes:

[0033] A reducing agent and combustion-supporting air are sprayed into a slag layer in a reduction zone of a horizontal reduction furnace using a reduction lance to generate coal gas and molten metal in the reduction zone. The coal gas enters a suspension melting zone from a coal gas outlet, and the molten metal and slag enter a settling zone of the horizontal reduction furnace for settling.

[0034] Mineral powder and oxygen-enriched air are supplied to the suspension melting zone of the vertical melting tower through a material lance, so that the mineral powder is suspended and melted in the suspension melting zone, and oxygen-containing gas is supplied to the secondary combustion chamber through a secondary combustion lance for further combustion with unburned coal gas.

[0035] According to the method for processing mineral powder according to the embodiment of the present disclosure, a reduction lance is used to inject a reducing agent and combustion-supporting air. The reducing agent is used to reduce the slag in the slag layer. The combustion-supporting air maintains the temperature of the reduction zone through combustion. The coal gas generated in the reduction zone enters the suspension melting zone through the coal gas outlet. The molten metal enters the settling zone of the horizontal reduction furnace for settling. A material lance injects oxygen-enriched air and mineral powder into the suspension melting zone. The oxygen-enriched air reacts and burns with CO, H2, and other substances in the coal gas, releasing a large amount of heat, which can maintain the suspension melting zone at a high temperature of 1500°C to 1600°C. At the same time, the coal gas moves upward, and the gases produced by the reaction of the coal gas and oxygen also move upward, thus forming an upward airflow in the suspension melting zone. Under the influence of the airflow in the suspension melting zone, the mineral powder is suspended in the suspension melting zone and rapidly melts at this high temperature. The melted droplets collide, grow, and fall into the reduction zone of the horizontal reduction furnace for reduction reaction. A secondary combustion lance supplies oxygen-containing gas to the secondary combustion chamber. The oxygen ejected by the lance further combusts with unburned coal gas, completely eliminating combustible components such as CO and H₂, and preventing explosions during subsequent flue gas treatment. This method allows the coal gas generated by the reduction process to be burned, releasing heat to melt the mineral powder. This fully utilizes the calorific value of the coal gas, reduces the input of external heat sources, and lowers production costs. Furthermore, the utilization of the coal gas eliminates the need for a coal gas collection and processing system, further reducing equipment investment costs.

[0036] In addition, the method for treating ore powder using an integrated ore powder suspension smelting reduction furnace according to the above embodiment of the present disclosure may also have the following additional technical features:

[0037] In some embodiments of the present disclosure, the ratio of the reducing agent and the combustion-supporting air sprayed from the reduction lance is controlled so that the ratio of the volume of CO in the coal gas to the volume of CO2 + CO is not less than 0.7. This can meet the required metal recovery rate.

[0038] In some embodiments of the present disclosure, the speed of the reducing agent sprayed out of the reduction spray gun is 80 m / s to 150 m / s.

[0039] In some embodiments of the present disclosure, the oxygen concentration of the oxygen-enriched air is not less than 70%, and the temperature of the oxygen-enriched air is 300° C. to 500° C. This can promote the melting of the mineral powder.

[0040] In some embodiments of the present disclosure, the temperature of the mineral powder injected by the material injection gun is 500° C. to 700° C. This can promote the melting of the mineral powder.

[0041] In some embodiments of the present disclosure, the speed at which the material spray gun sprays the mineral powder is 100 m / s to 150 m / s.

[0042] In some embodiments of the present disclosure, the mass ratio of the oxygen volume in the oxygen-enriched air injected by the material spray gun to the mineral powder is (1600Nm 3 :1t)~(2000Nm 3 : 1t). This can promote the melting of the mineral powder.

[0043] In some embodiments of the present disclosure, the flue gas flow rate in the suspension melting zone is 0.5 m / s to 1.0 m / s, 80 wt% of the mineral powder has a particle size of ≤ 2 mm, and the mineral powder resides in the suspension melting zone for 3 to 5 seconds, thereby promoting the melting of the mineral powder.

[0044] In some embodiments of the present disclosure, the flue gas stays in the secondary combustion chamber for no less than 1 second, thereby ensuring that the coal gas is fully burned in the secondary combustion chamber.

[0045] Additional aspects and advantages of the present disclosure will be given in part in the description that follows and, in part, will be obvious from the description that follows, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0047] FIG1 is a side structural diagram of a mineral powder suspension melting reduction integrated furnace according to an embodiment of the present disclosure;

[0048] FIG2 is a front structural diagram of a mineral powder suspension melting reduction integrated furnace according to another embodiment of the present disclosure;

[0049] FIG3 is a front structural diagram of a mineral powder suspension melting and reduction integrated furnace according to another embodiment of the present disclosure;

[0050] Figure markings: 100-vertical melting tower, 110-secondary combustion chamber, 111-secondary combustion lance, 112-necking section, 120-suspension melting zone, 121-material lance, 122-supplementary heat lance, 200-horizontal reduction furnace, 210-reduction zone, 211-gas outlet, 212-reduction lance, 213-combustion lance, 214-auxiliary lance, 220-sedimentation zone, 221-heating component, 222-smoke exhaust port, 223-metal discharge port, 224-slag discharge port, 225-accident discharge port, 230-partition wall, 240-slag layer, 250-metal melt layer, 260-first furnace bottom zone, 270-second furnace bottom zone. DETAILED DESCRIPTION

[0051] The present disclosure is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present disclosure in any way.

[0052] In one aspect of the present disclosure, a mineral powder suspension melting and reduction integrated furnace is provided. According to an embodiment of the present disclosure, referring to FIG1 and FIG2 , the mineral powder suspension melting and reduction integrated furnace includes: a vertical melting tower 100 and a horizontal reduction furnace 200 .

[0053] According to an embodiment of the present disclosure, the vertical melting tower 100 includes a secondary combustion chamber 110 and a suspension melting zone 120 from top to bottom. The secondary combustion chamber 110 is provided with a secondary combustion spray gun 111, and the suspension melting zone 120 is provided with a material spray gun 121. The material spray gun 121 is used to spray oxygen-enriched air and mineral powder into the suspension melting zone 120, and the gas outlet 211 is connected to the lower end of the suspension melting zone 120. Coal gas enters the suspension melting zone 120 from the gas outlet 211. A material injection lance 121 is installed in this zone, injecting oxygen-enriched air and mineral powder into the zone. The oxygen-enriched air reacts and combusts with CO, H2, and other substances in the coal gas, releasing a large amount of heat. This maintains the high temperature of 1500°C to 1600°C in the suspension melting zone 120. Simultaneously, the coal gas moves upward, and the gases produced by the reaction between the coal gas and oxygen also move upward. This creates an upward airflow in the suspension melting zone 120. The mineral powder is suspended in this airflow within the suspension melting zone 120 and rapidly melts at this high temperature. The melted droplets collide, grow, and fall into the horizontal reduction furnace 200 for reduction. As the droplets descend, they come into contact with the rising coal gas, exchanging heat and pre-reducing the droplets, thereby accelerating the reduction process within the horizontal reduction furnace 200. The unburned coal gas in the suspension melting zone 120 enters the secondary combustion chamber 110, which is provided with a secondary combustion lance 111. The oxygen ejected from the secondary combustion lance 111 is further burned with the unburned coal gas to completely eliminate the combustible components such as CO and H2 therein, thereby avoiding explosion during subsequent flue gas treatment.

[0054] According to an embodiment of the present disclosure, the ratio of the horizontal cross-sectional dimension of the secondary combustion chamber 110 to the horizontal cross-sectional dimension of the suspension melting zone 120 is (2-3):1. The inventors have found that the horizontal cross-sectional dimension of the secondary combustion chamber 110 must be larger than the horizontal cross-sectional dimension of the suspension melting zone 120 so that the speed of the airflow entering the secondary combustion chamber 110 from the suspension melting zone 120 can be reduced, thereby causing the droplets or mineral powder to sink downward due to the reduction of the airflow. In particular, by controlling the horizontal cross-sectional dimension of the secondary combustion chamber 110 to the horizontal cross-sectional dimension of the suspension melting zone 120 to be (2-3):1, the carried-out mineral powder particles can be settled into the suspension zone, thereby reducing the smoke rate. It should be noted that the shapes of the secondary combustion chamber 110 and the suspension melting zone 120 are not particularly limited, and can preferably be circular. The cross-sectional dimension refers to the length and width of the cross section of the secondary combustion chamber 110 and the suspension melting zone 120 in the horizontal direction. For example, if the cross section is circular, the cross-sectional dimension refers to the diameter of the circle.

[0055] According to an embodiment of the present disclosure, the lower end of the secondary combustion chamber 110 contracts to form a necking section 112, and the angle between the side wall of the necking section 112 and the horizontal direction is 65 degrees to 75 degrees. The inventors found that the angle between the side wall of the necking section 112 and the horizontal direction is 65 degrees to 75 degrees, which can not only prevent the continuous deposition of ash on the inner wall of the necking section 112 after the flue gas rises, thereby reducing the equipment failure rate, but also control the vertical melting tower 100 to have a suitable height, avoiding the increase in equipment cost due to excessive height. Furthermore, one end of the secondary combustion lance 111 is perpendicular to the side wall of the necking section 112 and extends into the secondary combustion chamber 110, so that the coal gas can be fully burned.

[0056] It should be noted that when the ratio of the horizontal cross-sectional dimension of the secondary combustion chamber 110 to the horizontal cross-sectional dimension of the suspension melting zone 120 is (2-3):1, the secondary combustion chamber 110 does not include the necking section 112 .

[0057] According to an embodiment of the present disclosure, the upper end of the secondary combustion chamber 110 is connected to a waste heat boiler (not shown), thereby effectively utilizing the heat of the exhaust flue gas. Furthermore, the upper end of the secondary combustion chamber 110 is connected to a mineral powder preheating device (not shown). After the mineral powder is preheated, it is sprayed into the suspension melting zone 120 through the material spray gun 121, which can increase the material conversion rate of the mineral powder in the suspension melting zone 120. Therefore, by connecting the upper end of the secondary combustion chamber 110 to the mineral powder preheating device, the high-temperature flue gas in the secondary combustion chamber 110 preheats the mineral powder, thereby more fully utilizing the flue gas energy of the system, reducing the supply of external heat, and reducing production costs.

[0058] According to an embodiment of the present disclosure, a supplemental heat lance 122 is provided below the suspension melting zone 120. This lance is located below the material injection lance 121, with one end extending into the suspension melting zone 120. This lance injects oxygen-enriched air. As the droplets fall, their temperature continuously decreases. The heat released by the oxygen-enriched air injected by the supplemental heat lance 122 and the combustion of the gas raises the droplet temperature and provides heat to the horizontal reduction furnace 200, thereby promoting the smelting reduction process.

[0059] According to an embodiment of the present disclosure, the supplementary heat spray gun 122 sprays fuel and oxygen-enriched air. The inventors found that the coal gas generated by the horizontal reduction furnace 200 may be insufficient in the suspension melting zone 120. At this time, the supplementary heat spray gun 122 sprays fuel and oxygen-enriched air, and the fuel burns to produce coal gas, which can solve the problem of insufficient coal gas in the suspension melting zone 120 and supplement heat for molten reduction. It should be noted that the fuel includes pulverized coal, coal gas, natural gas, etc. Furthermore, the speed of the fuel sprayed by the supplementary heat spray gun 122 is 100m / s to 150m / s, which can promote coal gas generation and heat supplement. It should be noted that by controlling the oxygen concentration of the oxygen-enriched air, the fuel can be burned to obtain coal gas.

[0060] According to an embodiment of the present disclosure, referring to Figure 2, the horizontal reduction furnace 200 includes a reduction zone 210 and a sedimentation zone 220 in sequence along the horizontal direction, and a partition wall 230 is provided between the reduction zone 210 and the sedimentation zone 220, and the lower end of the partition wall 230 extends into the slag layer 240 of the horizontal reduction furnace 200, and a gas outlet 211 is provided at the upper end of the reduction zone 210, and the gas outlet 211 is connected to the lower end of the suspended melting zone 120, and the reduction zone 210 is provided with a reduction lance 212, one end of the reduction lance 212 extends into the slag layer 240 of the reduction zone 210, and the reduction lance 212 is used to spray reducing agent and combustion-supporting air, and the sedimentation zone 220 is provided with a metal discharge port 223 and a slag discharge port 224. The horizontal reduction furnace 200 includes a reduction zone 210 and a sedimentation zone 220 in sequence along the horizontal direction. The reduction zone 210 is provided with a reduction lance 212. One end of the reduction lance 212 extends into the slag layer 240 of the reduction zone 210. The reduction lance 212 is used to spray reducing agent and combustion-supporting air. The O2 in the combustion-supporting air and the reducing agent undergo an incomplete combustion reaction at the outlet of the reduction lance 212, releasing heat and stirring the liquid slag in the slag layer 240. The remaining reducing agent reduces the liquid slag in the slag layer 240. The heat from the combustion of the combustion-supporting air is used to maintain the temperature of the reduction zone 210. A partition wall 230 is provided between the reduction zone 210 and the sedimentation zone 220. The lower end of the partition wall 230 extends into the slag layer 240 of the horizontal reduction furnace 200. After the slag reacts in the reduction zone 210, it enters the sedimentation zone 220 from the siphon port between the partition wall 230 and the bottom of the horizontal reduction furnace 200. Then, the metal in the sedimentation zone 220 is deposited to form a metal melt layer 250. The sedimentation zone 220 is provided with a metal discharge port 223 and a slag discharge port 224. The metal in the metal melt layer 250 can be discharged from the metal discharge port 223, and the upper slag is discharged from the slag discharge port 224.

[0061] According to an embodiment of the present disclosure, the settling area 220 is further provided with a heating assembly 221 and a smoke exhaust port 222. The smoke generated in the settling area 220 is discharged from the smoke exhaust port 222. The heating assembly 221 is used to maintain the temperature of the settling area 220 to prevent the metal from freezing. The settling area 220 may also be provided with an emergency exhaust port 225. When a device malfunctions, the slag in the settling area 220 can be discharged from the emergency exhaust port 225. It should be noted that the heating assembly 221 is used to replenish the temperature of the settling area 220. Those skilled in the art can select the heating assembly 221 according to actual needs. For example, the heating assembly 221 may include electrodes, heating wires, etc.

[0062] A gas outlet 211 is provided at the upper end of the reduction zone 210. The gas generated after the reduction reaction in the reduction zone 210 is discharged through the gas outlet 211. Because a partition wall 230 is provided between the reduction zone 210 and the settling zone 220, and the lower end of the partition wall 230 extends into the slag layer 240 of the horizontal reduction furnace 200, the reduction zone 210 and the settling zone 220 each form an independent space. The gas generated in the reduction zone 210 is discharged through the gas outlet 211. The gas outlet 211 is connected to the lower end of the suspension melting zone 120. Therefore, the gas generated in the reduction zone 210 enters the suspension melting zone 120 for combustion and heat release. The combustion heat release melts the mineral powder, thereby fully utilizing the calorific value of the gas, reducing the input of external heat sources, and lowering production costs. Furthermore, the utilization of the gas saves the gas collection and processing system, further reducing equipment investment costs. It should be noted that the combustion-supporting air includes oxygen, oxygen-enriched air, etc. It should be noted that the side walls of the horizontal reduction furnace 200 located in the slag layer 240 utilize a water-cooled slag structure, while the side walls of the horizontal reduction furnace 200 located in the molten metal layer 250 utilize a refractory brick structure. The siphon opening between the partition wall 230 and the bottom of the horizontal reduction furnace 200 refers to the distance between the partition wall 230 and the bottom of the horizontal reduction furnace 200. Because the partition wall 230 separates the two sides, the liquid slag below the partition wall 230 is connected. The liquid levels on both sides of the partition wall 230 automatically adjust to equilibrium, thus forming the siphon opening.

[0063] According to an embodiment of the present disclosure, referring to FIG2 , a gas outlet 211 is provided at the upper end of the reduction zone 210, away from the settling zone 220. Liquid droplets formed by melting the mineral powder in the suspension melting zone 120 enter one end of the reduction zone 210. As the liquid slag accumulates, it moves toward the end away from the gas outlet 211, where it reacts in the reduction zone 210 and is deposited in the settling zone 220.

[0064] According to an embodiment of the present disclosure, referring to FIG3 , settling zones 220 are provided at both ends of the reduction zone 210 in the horizontal direction. Liquid droplets formed by melting the mineral powder in the suspended melting zone 120 enter the reduction zone 210 . As the liquid slag accumulates, it moves toward the settling zones 220 at both ends, where it reacts and settles.

[0065] According to an embodiment of the present disclosure, the lower end of the partition wall 230 extends into the slag layer 240 of the reduction zone 210 to a depth of no less than 300 mm. The inventors have discovered that this ensures that the reduction zone 210 and the settling zone 220 form independent spaces, thereby preventing the coal gas generated in the reduction zone 210 from overflowing into the settling zone 220 and improving coal gas utilization. It should be noted that the aforementioned depth refers to the vertical distance between the lower end of the partition wall 230 and the upper surface of the slag layer 240.

[0066] According to an embodiment of the present disclosure, the distance between the lower end of the partition wall 230 and the bottom of the horizontal reduction furnace 200 is 300 mm to 500 mm, which is conducive to the flow of liquid slag from the reduction zone 210 into the sedimentation zone 220, and the liquid slag forms a stable flow speed, which is conducive to the collection of metal.

[0067] According to an embodiment of the present disclosure, the depth of one end of the reduction lance 212 extending into the slag layer 240 is 200 mm to 300 mm. This allows for sufficient stirring of the slag in the slag layer 240, avoids splashing or insufficient stirring power, and improves reduction efficiency. It should be noted that the aforementioned depth refers to the vertical distance from the end of the reduction lance 212 extending into the slag layer 240 to the upper surface of the slag layer 240.

[0068] According to an embodiment of the present disclosure, a combustion lance 213 is provided below the gas outlet 211. The combustion lance 213 is used to inject fuel and combustion-supporting air. One end of the combustion lance 213 extends into the slag layer 240 to a depth of 200 mm to 300 mm. The author of the disclosure discovered that when the mineral powder melts in the suspension melting zone 120, droplets may envelop the mineral powder particles. The encapsulated mineral powder is not fully melted in the suspension melting zone 120. The combustion lance 213 releases heat through fuel combustion, which completely melts the unmelted mineral powder. At the same time, the heat provided by the combustion lance 213 is more conducive to the subsequent reduction reaction. Furthermore, the fuel and combustion-supporting air injected by the combustion lance 213 are controlled so that the oxygen excess coefficient is 0.9 to 1.1, so that the unmelted mineral powder can be fully melted. It should be noted that the above-mentioned depth refers to the vertical distance from one end of the combustion lance 213 extending into the slag layer 240 to the upper surface of the slag layer 240.

[0069] According to an embodiment of the present disclosure, the bottom of the horizontal reduction furnace 200 is horizontally divided into a first furnace bottom zone 260 and a second furnace bottom zone 270. The first furnace bottom zone 260 is taller than the second furnace bottom zone 270, and the partition wall 230 is located above the second furnace bottom zone 270. The liquid slag completes the reduction reaction in the first furnace bottom zone 260. Because the first furnace bottom zone 260 is taller than the second furnace bottom zone 270, the liquid slag after the reaction is more likely to gather in the second furnace bottom zone 270, thereby facilitating metal collection. Furthermore, the horizontal distance d between the partition wall 230 and the first furnace bottom zone 260 is 500 mm to 1000 mm.

[0070] According to an embodiment of the present disclosure, the reduction zone 210 is provided with an auxiliary lance 214, one end of which extends into the slag layer 240 of the second furnace bottom zone 270. The auxiliary lance 214 is used to spray sulfur or coal powder, thereby completing sulfidation (when producing low-grade nickel matte) or carburizing operations (when producing molten iron). Furthermore, one end of the auxiliary lance 214 is 150 mm to 250 mm away from the interface between the molten metal layer 250 and the slag layer 240 of the reduction zone 210. The angle between the auxiliary lance 214 and the horizontal direction is 60 to 75 degrees, thereby reducing the length of the auxiliary lance 214 and reducing equipment costs.

[0071] Another aspect of the present disclosure provides a method for treating ore powder using the above-mentioned ore powder suspension smelting reduction integrated furnace. According to an embodiment of the present disclosure, the method includes:

[0072] S100: Use a reduction spray gun to spray the reducing agent and combustion air into the slag layer in the reduction zone of the horizontal reduction furnace

[0073] In this step, a reducing agent and combustion-supporting air are sprayed into the slag layer 240 in the reduction zone 210 of the horizontal reduction furnace 200 using a reduction lance 212. The reducing agent is used to reduce the slag in the slag layer 240, and the combustion-supporting air maintains the temperature of the reduction zone 210 through combustion, thereby generating coal gas and molten metal in the reduction zone 210. The coal gas enters the suspension melting zone 120 through the coal gas outlet 211, and the molten metal and slag enter the settling zone 220 of the horizontal reduction furnace 200 for settling.

[0074] According to the embodiments of the present disclosure, the ratio of the reducing agent and combustion-supporting air ejected from the reduction lance 212 in the reduction zone 210 is controlled to ensure that the ratio of the volume of CO in the coal gas to the sum of the volumes of CO₂ + CO₂ is no less than 0.7, thereby meeting the required metal recovery rate. Furthermore, the velocity of the reducing agent ejected from the reduction lance 212 is 80 m / s to 150 m / s, thereby increasing the liquid slag reduction rate in the reduction zone 210.

[0075] S200: Mineral powder and oxygen-enriched air are supplied to the suspension melting zone of the vertical melting tower through the material injection gun

[0076] In this step, mineral powder and oxygen-enriched air are supplied to the suspension melting zone 120 of the vertical melting tower 100 via a material injection lance 121. The oxygen-enriched air reacts and combusts with CO, H2, and other gases in the coal gas, releasing a large amount of heat. This maintains the suspension melting zone 120 at a high temperature of 1500°C to 1600°C. Simultaneously, the coal gas moves upward, and the gases produced by the reaction between the coal gas and oxygen also move upward. This creates an upward airflow in the suspension melting zone 120. Under the influence of the airflow in the suspension melting zone 120, the mineral powder becomes suspended within the suspension melting zone 120 and rapidly melts at this high temperature. The melted droplets collide, grow, and fall into the reduction zone 210 of the horizontal reduction furnace 200 for reduction. A secondary combustion lance 111 supplies oxygen-containing gas to the secondary combustion chamber 110. The oxygen injected by the secondary combustion lance 111 further combusts with the unburned coal gas, completely eliminating combustible components such as CO and H2, thereby preventing explosions during subsequent flue gas treatment. Therefore, this method can be used to burn the coal gas generated by reduction, and the combustion heat can melt the mineral powder, thereby fully utilizing the calorific value of the coal gas, reducing the input of external heat sources, and lowering production costs. After the coal gas is utilized, the coal gas collection and processing system is saved, further reducing the equipment investment cost.

[0077] According to an embodiment of the present disclosure, the oxygen-enriched air ejected from the material spray gun 121 has an oxygen concentration of no less than 70%, and the temperature of the oxygen-enriched air is between 300°C and 500°C. Controlling the oxygen concentration of the oxygen-enriched air to no less than 70% helps reduce flue gas volume, improve thermal efficiency, and avoid excessive flue gas flow and the removal of excessive heat. Properly preheating the oxygen-enriched air between 300°C and 500°C can increase the combustion temperature, thereby increasing the rate of combustion.

[0078] According to an embodiment of the present disclosure, the temperature of the mineral powder injected by the material injection gun 121 is 500°C to 700°C. Preheating the mineral powder to 500°C to 700°C before injecting it into the suspension melting zone 120 can promote rapid melting of the mineral powder in the suspension melting zone 120. Furthermore, the speed of the mineral powder injected by the material injection gun 121 is 100m / s to 150m / s, thereby fully melting the mineral powder.

[0079] According to the embodiment of the present disclosure, the mass ratio of oxygen volume to mineral powder in the oxygen-enriched air injected by the material spray gun 121 is (1600Nm 3 :1t)~(2000Nm 3 The inventors have found that when the volume ratio of oxygen injected by the material injection gun 121 to the mass ratio of the mineral powder is within the above range, the heat required for melting the material can be ensured.

[0080] According to an embodiment of the present disclosure, the flue gas flow rate in the suspension melting zone 120 is 0.5 m / s to 1.0 m / s, 80 wt% of the mineral powder has a particle size of ≤ 2 mm, and the mineral powder stays in the suspension melting zone 120 for 3 to 5 seconds, thereby promoting the melting of the mineral powder.

[0081] According to an embodiment of the present disclosure, the volume of the secondary combustion chamber 110 is controlled to ensure that the flue gas stays in the secondary combustion chamber 110 for no less than 1 second, thereby ensuring that the coal gas is fully burned in the secondary combustion chamber 110.

[0082] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A mineral powder suspension melting reduction integrated furnace, characterized in that: include: A vertical melting tower, the vertical melting tower comprises a secondary combustion chamber and a suspension melting zone from top to bottom, the secondary combustion chamber is provided with a secondary combustion spray gun, the suspension melting zone is provided with a material spray gun, and the material spray gun is used to spray oxygen-enriched air and mineral powder into the suspension melting zone; A horizontal reduction furnace, which includes a reduction zone and a sedimentation zone in sequence along the horizontal direction, a partition wall is provided between the reduction zone and the sedimentation zone, the lower end of the partition wall extends into the slag layer of the horizontal reduction furnace, a gas outlet is provided at the upper end of the reduction zone, and the gas outlet is connected to the lower end of the suspended melting zone, the reduction zone is provided with a reduction lance, one end of the reduction lance extends into the slag layer of the reduction zone, the reduction lance is used to spray a reducing agent and combustion-supporting air, and the sedimentation zone is provided with a metal discharge port and a slag discharge port.

2. The integrated furnace according to claim 1, characterized in that: The gas outlet is provided at the upper end of the reduction zone away from the settling zone.

3. The integrated furnace according to claim 1, characterized in that: The sedimentation zones are respectively arranged at two ends of the reduction zone along the horizontal direction.

4. The integrated furnace according to claims 1-3, characterized in that: The settling area is provided with a heating component and / or a smoke exhaust port.

5. The integrated furnace according to any one of claims 1 to 4, characterized in that: The depth of the lower end of the partition wall extending into the slag layer in the reduction zone is not less than 300 mm.

6. The integrated furnace according to any one of claims 1 to 5, characterized in that: The distance between the lower end of the partition wall and the bottom of the horizontal reduction furnace is 300 mm to 500 mm.

7. The integrated furnace according to any one of claims 1 to 6, characterized in that: One end of the reduction lance extends into the slag layer to a depth of 200 mm to 300 mm.

8. The integrated furnace according to any one of claims 1 to 7, characterized in that: A combustion lance is provided below the coal gas outlet, and the combustion lance is used to inject fuel and combustion-supporting air. One end of the combustion lance extends into the slag layer to a depth of 200 mm to 300 mm.

9. The integrated furnace according to any one of claims 1 to 8, characterized in that: The bottom of the horizontal reduction furnace is divided into a first furnace bottom area and a second furnace bottom area along the horizontal direction. The height of the first furnace bottom area is greater than that of the second furnace bottom area. The partition wall is located above the second furnace bottom area.

10. The integrated furnace according to claim 9, characterized in that: The horizontal distance between the partition wall and the first furnace bottom area is 500 mm to 1000 mm.

11. The integrated furnace according to claim 9 or 10, characterized in that: The reduction zone is provided with an auxiliary lance, one end of which extends into the slag layer in the second furnace bottom zone, and the auxiliary lance is used for spraying sulfur or coal powder.

12. The integrated furnace according to claim 11, characterized in that: The distance between one end of the auxiliary lance and the interface between the molten metal layer and the slag layer in the reduction zone is 150 mm to 250 mm.

13. The integrated furnace according to claim 11 or 12, characterized in that: The angle between the auxiliary spray gun and the horizontal direction is 60 degrees to 75 degrees.

14. The integrated furnace according to any one of claims 1 to 13, characterized in that: The ratio of the horizontal cross-sectional dimension of the secondary combustion chamber to the horizontal cross-sectional dimension of the suspension melting zone is (2-3):

1.

15. The integrated furnace according to any one of claims 1 to 14, characterized in that: The lower end of the secondary combustion chamber contracts to form a necking section, and the angle between the side wall of the necking section and the horizontal direction is 65 degrees to 75 degrees.

16. The integrated furnace according to claim 15, characterized in that: One end of the secondary combustion lance is perpendicular to the side wall of the necking section and extends into the secondary combustion chamber.

17. The integrated furnace according to any one of claims 1 to 16, characterized in that: The upper end of the secondary combustion chamber is connected to a waste heat boiler.

18. The integrated furnace according to any one of claims 1 to 16, characterized in that: The upper end of the secondary combustion chamber is connected to a mineral powder preheating device.

19. The integrated furnace according to any one of claims 1 to 18, characterized in that: A supplementary heat spray gun is provided below the suspension melting zone. The supplementary heat spray gun is located below the material spray gun. One end of the supplementary heat spray gun extends into the suspension melting zone. The supplementary heat spray gun is used to spray the oxygen-enriched air.

20. The integrated furnace according to any one of claims 19, characterized in that: The supplementary heat spray gun is used for spraying fuel and the oxygen-enriched air.

21. A method for treating mineral powder using the mineral powder suspension smelting reduction integrated furnace according to any one of claims 1 to 20, characterized in that: include: A reducing agent and combustion-supporting air are sprayed into a slag layer in a reduction zone of a horizontal reduction furnace by a reducing spray gun, so as to generate coal gas and molten metal in the reduction zone, the coal gas enters a suspension melting zone from a coal gas outlet, and the molten metal and slag enter a settling zone of the horizontal reduction furnace for settling; Mineral powder and oxygen-enriched air are supplied to the suspension melting zone of the vertical melting tower through a material spray gun, so that the mineral powder is suspended and melted in the suspension melting zone, and oxygen-containing gas is supplied to the secondary combustion chamber through a secondary combustion spray gun for further combustion with unburned coal gas.

22. The method according to claim 21, characterized in that The ratio of the reducing agent and the combustion-supporting air sprayed from the reduction spray gun is controlled so that the ratio of the volume of CO in the coal gas to the sum of the volumes of CO2+CO is not less than 0.

7.

23. The method according to claim 21 or 22, characterized in that The speed of the reducing agent sprayed out of the reducing spray gun is 80m / s to 150m / s.

24. The method according to any one of claims 21 to 23, characterized in that The oxygen volume concentration of the oxygen-enriched air is not less than 70%, and the temperature of the oxygen-enriched air is 300°C to 500°C.

25. The method according to any one of claims 21 to 24, characterized in that The temperature of the mineral powder sprayed by the material spray gun is 500°C to 700°C.

26. The method according to any one of claims 21 to 25, characterized in that The mass ratio of the oxygen volume in the oxygen-enriched air sprayed by the material spray gun to the mineral powder is (1600Nm 3 :1t)~(2000Nm 3 :1t).

27. The method according to any one of claims 21 to 26, characterized in that The flue gas flow rate in the suspension melting zone is 0.5 m / s to 1.0 m / s, 80 wt% of the mineral powder has a particle size of ≤2 mm, and the residence time of the mineral powder in the suspension melting zone is 3 s to 5 s.

28. The method according to any one of claims 21 to 27, characterized in that The flue gas stays in the secondary combustion chamber for no less than 1 second.

29. The method according to any one of claims 21 to 28, characterized in that The speed at which the material spray gun sprays the mineral powder is 100m / s to 150m / s.

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