Siderite microwave magnetizing roasting device and method

Abstract

The invention relates to the technical field of metallurgical magnetizing roasting equipment, in particular to a siderite microwave magnetizing roasting device and method.The siderite microwave magnetizing roasting device comprises a feeding belt conveyor, a microwave magnetizing roasting shaft furnace and a desulfurizing tower, the top end of the microwave magnetizing roasting shaft furnace is connected with an oxidation heat release shaft furnace, and the top end of the oxidation heat release shaft furnace is connected with a preheating shaft furnace; the drying shaft furnace is connected to the top end of the preheating shaft furnace, heat energy is comprehensively utilized under the action of the waste heat transmission mechanism and a connecting part of the waste heat transmission mechanism, energy consumption is greatly reduced, the energy consumption per ton treatment is reduced to 100 kilowatt-hour electricity or below, and the production cost is greatly reduced. According to the method, microwave is adopted for assisting catalytic heating, the decomposition time of siderite is greatly shortened, the productivity is improved, meanwhile, straw, wheat straw, biochemical sludge and the like are fully utilized as fuel in the production process, and contribution is made to comprehensive utilization of resources.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical magnetization roasting equipment, in particular to a siderite microwave magnetization roasting device and method. Background Art

[0002] Lean ore is represented by siderite. The mineral composition of siderite ore is complex, and it often coexists with calcium, manganese, magnesium, etc., resulting in low iron grade and difficulty in large-scale development and utilization. The traditional equipment for roasting siderite is a rotary kiln, and the inherent process characteristics of the rotary kiln determine its limitations in energy consumption, processing capacity, efficiency, etc. The main reasons are mainly reflected in the following parts: 1. In the rotary kiln, materials are often piled up at the bottom of the kiln, and the airflow flows over the surface of the material layer. This accumulation state results in a relatively small contact area between the airflow and the material, and it is difficult for the airflow to penetrate the interior of the material layer, thereby limiting the heat transfer efficiency. Due to the limited contact area, the heat transfer is not sufficient, resulting in a slow heat transfer speed and reduced efficiency. 2. The waste gas generated by traditional equipment after heating the material is often directly filtered and discharged, but this part of the waste gas is often at a high temperature, and it is difficult to directly discharge and treat it, and the heat is not utilized, resulting in heat waste; To this end, in view of the shortcomings of low operating rate and high production cost of traditional rotary kilns, we propose a microwave magnetization roasting device and method for siderite. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a microwave magnetization roasting device for siderite, comprising a feeding belt conveyor, a microwave magnetization roasting vertical furnace and a desulfurization tower, wherein the microwave magnetization roasting vertical furnace is connected to an oxidation exothermic vertical furnace at the top, the oxidation exothermic vertical furnace is connected to a preheating vertical furnace at the top, the preheating vertical furnace is connected to a drying vertical furnace at the top, and the drying vertical furnace is connected to the feeding belt conveyor for preliminarily drying the siderite conveyed by the feeding belt conveyor; The invention also comprises a first slow cooling vertical furnace connected to the bottom end of the microwave magnetization vertical furnace, the bottom end of the first slow cooling vertical furnace is connected to the second slow cooling vertical furnace, the top end of the second slow cooling vertical furnace is connected to the first slow cooling vertical furnace, and the bottom end is connected to the third slow cooling vertical furnace, the top end of the third slow cooling vertical furnace is connected to the bottom end of the second slow cooling vertical furnace, and the bottom end is connected to the discharge vertical furnace, the top end of the discharge vertical furnace is connected to the bottom end of the third slow cooling vertical furnace, and the bottom end is connected to the water quenching tank, and the water quenching tank is provided with a heat exchange coil, and the distribution state is as follows: the drying vertical furnace, the preheating vertical furnace, the oxidation exothermic vertical furnace, the microwave magnetization roasting vertical furnace, the first slow cooling vertical furnace, the second slow cooling vertical furnace, the third slow cooling vertical furnace, the discharge vertical furnace, and the water quenching tank are sequentially connected in series and sealed from top to bottom, the siderite moves from top to bottom by gravity, and the hot gas heated by the heat exchange coil in the water quenching tank moves from bottom to top and is discharged from the drying vertical furnace; It also includes a waste heat transfer mechanism connected to the desulfurization tower, the drying vertical furnace, the preheating vertical furnace, the oxidation exothermic vertical furnace, the microwave magnetization roasting vertical furnace, the first slow cooling vertical furnace, the second slow cooling vertical furnace, and the third slow cooling vertical furnace, and a finished product processing mechanism installed on the water quenching tank. The waste heat transfer mechanism utilizes the thermal energy in the components connected to it to perform corresponding thermal processing on the siderite, and the finished product processing mechanism performs ball milling and screening on the preliminarily processed siderite to convert it into iron concentrate.

[0004] Preferably, the microwave magnetization roasting vertical furnace is provided with an air guide wall, and the outer wall is provided with a microwave heater, the air guide wall is evenly arranged with air holes, and the microwave heater provides microwave energy for the microwave magnetization roasting vertical furnace, and the microwave energy evenly heats the siderite and catalyzes the decomposition reaction.

[0005] Preferably, an exhaust port is provided at the top of the drying vertical furnace, a feed port is provided on the drying vertical furnace, the feed port is located at the discharge end of the feed belt conveyor, and a first wind hood is provided in the drying vertical furnace, which evenly disperses the hot air in the drying vertical furnace.

[0006] Preferably, a second hood is provided in the preheating vertical furnace, and the second hood has the function of evenly dispersing hot air, which comes from the second slow cooling vertical furnace and is used to preheat the mixture of siderite and additives in this section.

[0007] Preferably, a third hood is provided in the oxidation exothermic vertical furnace, and the third hood has the function of evenly dispersing hot air. This part of hot air comes from the first slow cooling vertical furnace, and the additive is burned and released heat in this section to heat the siderite.

[0008] Preferably, the waste heat transfer mechanism comprises a first heat exchanger, a second heat exchanger and a third heat exchanger respectively arranged in the first slow cooling vertical furnace, the second slow cooling vertical furnace and the third slow cooling vertical furnace, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are all made of heat-conducting metal; It also includes a first heat exchanger, a second heat exchanger, and a third heat exchanger arranged on one side of the first slow cooling vertical furnace, the second slow cooling vertical furnace, and the third slow cooling vertical furnace. The first heat exchanger, the second heat exchanger, and the third heat exchanger are respectively connected to one side of the first heat exchanger, the second heat exchanger, and the third heat exchanger through pipelines, and the three are interconnected and distributed in a straight line. The exhaust port on the drying vertical furnace is connected to the inlet end of the first heat exchanger, and the outlet end of the third heat exchanger is connected to the desulfurization tower; It also includes a combustion-supporting fan, a first blower, and a second blower. The air inlets of the combustion-supporting fan, the first blower, and the second blower are respectively connected to the first heat exchanger, the second heat exchanger, and the third heat exchanger. The air outlet of the combustion-supporting fan is respectively connected to the air guide wall in the microwave magnetization roasting vertical furnace and the third wind hood in the oxidation exothermic vertical furnace through a pipeline. The air outlets of the first blower and the second blower are respectively connected to the second wind hood in the preheating vertical furnace and the first wind hood in the drying vertical furnace.

[0009] Preferably, the finished product processing mechanism includes a gear roller unloader arranged in the unloading vertical furnace, and also includes a scale plate machine arranged in the water quenching tank, the end of the scale plate machine is connected to a ball mill, and the discharge port of the ball mill is provided with a magnetic separator.

[0010] Preferably, a dust collector is provided between the desulfurization tower and the third heat exchanger, the inlet of the dust collector is connected to the outlet of the third heat exchanger, and the outlet is connected to the inlet of the desulfurization tower.

[0011] Preferably, an induced draft fan is provided at the top of the desulfurization tower, and a chimney is provided on the induced draft fan.

[0012] A method for using a siderite microwave magnetization roasting device comprises the following steps: S1: First, the siderite is crushed into small pieces of 10-30 mm, and the crushed siderite and additives are put into the feeding belt conveyor in proportion. Then, after being transmitted by the feeding belt conveyor, the siderite and additives enter the drying vertical furnace. The mass ratio of siderite and additives is 10:0.5 to 10:1. The additives are straw, wheat straw, dried biochemical sludge and other solids with a certain calorific value and a low ignition point; S2: Siderite and additives are dried in a drying vertical furnace at a drying temperature of 100-150°C. The heat comes from two parts: one part is the hot air moving upward in the preheating vertical furnace; the other part is the room temperature air heated to 50-60°C by the third heat exchanger, and then heated to 300-350°C by the third heat exchanger, and then blown into the first hood by the second blower and evenly dispersed; S3: Siderite and additives are preheated to above 300℃ in the preheating vertical furnace. The heat comes from two parts: one part is the hot air moving upward in the oxidation exothermic vertical furnace; the other part is the room temperature air heated to 80-90℃ by the second heat exchanger, and then heated to 400-450℃ by the second heat exchanger, and then blown into the second hood by the first blower and evenly dispersed; S4: Siderite and additives are preheated to above 450℃ in the oxidation exothermic vertical furnace. The heat comes from four parts: the first part is the hot air moving upward in the microwave magnetization roasting vertical furnace; the second part is the hot air generated by the CO oxidation exothermic in the air guide wall moving upward; the third part is the oxidation reaction of the additives to release a large amount of heat; the fourth part is the room temperature air heated to 110-120℃ by the first heat exchanger, and then heated to 500-550℃ by the first heat exchanger, and then blown into the third air hood by the combustion-supporting fan and evenly dispersed; S5: The siderite is catalyzed by microwaves and heated to 600-700°C in a microwave magnetization roasting shaft furnace. The siderite is rapidly decomposed, and the generated CO and CO2 gases penetrate into the air guide wall. The CO gas undergoes an oxidation reaction in the air guide wall, releases heat, and moves upward, preheating the siderite in the shaft furnace above it. S6: The decomposed iron ore is cooled to 250-300°C by the first slow cooling vertical furnace, the second slow cooling vertical furnace, and the third slow cooling vertical furnace, and then discharged into the water of the water quenching tank by the toothed roller unloader for oxygen-free water quenching. The iron ore after water quenching is scraped from the water quenching tank by the scale plate machine, and then ball milled by the ball mill, and then Fe3O4 is selected by the magnetic separator; S7: The generated flue gas is cooled to below 100°C after heat exchange in the first heat exchanger, the second heat exchanger and the third heat exchanger, and then passes through a dust collector to remove particulate matter, and then passes through a desulfurization tower to remove SO2 in the flue gas, and finally is blown into the chimney by an induced draft fan to meet emission standards.

[0013] The present invention has at least the following beneficial effects: 1. Under the action of the waste heat transfer mechanism and its connecting parts, the hot air flow heats the materials in each furnace from bottom to top, fully contacts the materials, and makes comprehensive use of the heat energy, which greatly saves energy consumption. The energy consumption per ton of processing is reduced to less than 100 kWh, which greatly reduces the production cost; 2. The present invention adopts microwaves for auxiliary catalytic heating, which greatly accelerates the decomposition time of siderite and improves the production capacity. At the same time, straw, wheat straw, biochemical sludge, etc. are fully used as fuel in the production process, which contributes to the comprehensive utilization of resources; 3. The reasonable distribution of parts in the present invention makes the overall equipment occupy a small area, greatly reduces the site cost required for construction, and has a good magnetization roasting effect, and the iron grade of siderite is increased from 40-43% to 62-65%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a structural schematic diagram of another viewing angle of the present invention; Figure 3 It is a schematic diagram of the two-dimensional internal structure of the present invention.

[0015] In the figure: 1, feeding belt conveyor; 2, drying vertical furnace; 201, exhaust port; 202, feeding port; 203, first wind hood; 3, preheating vertical furnace; 301, second wind hood; 4, oxidation exothermic vertical furnace; 401, third wind hood; 5, microwave magnetization roasting vertical furnace; 501, air guide wall; 502, microwave heater; 6, first slow cooling vertical furnace; 601, first heat exchanger; 7, second slow cooling vertical furnace; 701, second heat exchanger; 8, third slow cooling Vertical furnace; 801, third heat exchanger; 9, unloading vertical furnace; 901, gear roller unloader; 10, water quenching tank; 1001, heat exchange coil; 11, combustion-supporting fan; 12, first blower; 13, second blower; 14, scale machine; 15, ball mill; 16, magnetic separator; 17, first heat exchanger; 18, second heat exchanger; 19, third heat exchanger; 20, dust collector; 21, desulfurization tower; 22, induced draft fan; 23, chimney. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention. Example

[0017] See also Figure 1-3 The present invention provides a technical solution: a microwave magnetization roasting device for siderite, comprising a feeding belt conveyor 1, a microwave magnetization roasting vertical furnace 5 and a desulfurization tower 21, the microwave magnetization roasting vertical furnace 5 is connected to an oxidation exothermic vertical furnace 4 at the top, the oxidation exothermic vertical furnace 4 is connected to a preheating vertical furnace 3 at the top, the preheating vertical furnace 3 is connected to a drying vertical furnace 2 at the top, the drying vertical furnace 2 is connected to the feeding belt conveyor 1, and is used for preliminarily drying the siderite conveyed by the feeding belt conveyor 1; The invention also includes a first slow cooling vertical furnace 6 connected to the bottom end of the microwave magnetization vertical furnace, the bottom end of the first slow cooling vertical furnace 6 is connected to a second slow cooling vertical furnace 7, the top end of the second slow cooling vertical furnace 7 is connected to the first slow cooling vertical furnace 6, the bottom end is connected to a third slow cooling vertical furnace 8, the top end of the third slow cooling vertical furnace 8 is connected to the bottom end of the second slow cooling vertical furnace 7, the bottom end is connected to a discharge vertical furnace 9, the top end of the discharge vertical furnace 9 is connected to the bottom end of the third slow cooling vertical furnace 8, the bottom end is connected to a water quenching tank 10, and a water quenching tank 10 is provided in the water quenching tank 10 There are heat exchange coils 1001, which are distributed as follows: a drying vertical furnace 2, a preheating vertical furnace 3, an oxidation exothermic vertical furnace 4, a microwave magnetization roasting vertical furnace 5, a first slow cooling vertical furnace 6, a second slow cooling vertical furnace 7, a third slow cooling vertical furnace 8, a discharge vertical furnace 9, and a water quenching tank 10 are connected in series and sealed from top to bottom. The siderite moves from top to bottom by gravity, and the hot gas heated by the heat exchange coils 1001 in the water quenching tank 10 moves from bottom to top and is discharged from the drying vertical furnace 2; It also includes a waste heat transfer mechanism connected to the desulfurization tower 21, the drying vertical furnace 2, the preheating vertical furnace 3, the oxidation exothermic vertical furnace 4, the microwave magnetization roasting vertical furnace 5, the first slow cooling vertical furnace 6, the second slow cooling vertical furnace 7, and the third slow cooling vertical furnace 8, and a finished product processing mechanism installed on the water quenching tank 10. The waste heat transfer mechanism utilizes the thermal energy in the components connected to it to perform corresponding heat treatment on the siderite, and the finished product processing mechanism ball-mills and screens the siderite processed by the waste heat transfer mechanism to convert it into iron concentrate.

[0018] The design of vertical series connection between the components greatly reduces the footprint of the overall equipment.

[0019] The microwave magnetization roasting vertical furnace 5 is provided with an air guide wall 501, and a microwave heater 502 is provided on the outer wall. The air guide wall 501 is evenly arranged with air holes. The microwave heater 502 provides microwave energy for the microwave magnetization roasting vertical furnace 5. The microwave energy evenly heats the siderite and catalyzes the decomposition reaction.

[0020] An exhaust port 201 is provided at the top of the drying vertical furnace 2, a feed port 202 is provided on the drying vertical furnace 2, and the feed port 202 is located at the discharge end of the feed belt conveyor 1. A first wind hood 203 is provided in the drying vertical furnace 2, and the first wind hood 203 evenly disperses the hot air in the drying vertical furnace 2.

[0021] The preheating vertical furnace 3 is provided with a second hood 301, which has the function of evenly dispersing hot air. This part of hot air comes from the second slow cooling vertical furnace 7 and is used to preheat the siderite and additive mixture in this section.

[0022] The oxidation exothermic vertical furnace 4 is provided with a third hood 401, which has the function of evenly dispersing hot air. This part of hot air comes from the first slow cooling vertical furnace 6. The additive is burned and released heat in this section to heat the siderite.

[0023] The waste heat transfer mechanism includes a first heat exchanger 601, a second heat exchanger 701, and a third heat exchanger 801, which are respectively arranged in the first slow cooling vertical furnace 6, the second slow cooling vertical furnace 7, and the third slow cooling vertical furnace 8. The first heat exchanger 601, the second heat exchanger 701, and the third heat exchanger 801 are all made of heat-conducting metal materials. The air in each heat exchanger indirectly exchanges heat with the siderite to avoid oxidation of Fe3O4. It also includes a first heat exchanger 17, a second heat exchanger 18, and a third heat exchanger 19 arranged on one side of the first slow cooling vertical furnace 6, the second slow cooling vertical furnace 7, and the third slow cooling vertical furnace 8. The first heat exchanger 17, the second heat exchanger 18, and the third heat exchanger 19 are respectively connected to one side of the first heat exchanger 601, the second heat exchanger 701, and the third heat exchanger 801 through pipelines, and the three are interconnected and distributed in a straight line. The exhaust port 201 on the drying vertical furnace 2 is connected to the inlet end of the first heat exchanger 17, and the outlet end of the third heat exchanger 19 is connected to the desulfurization tower 21; It also includes a combustion-supporting fan 11, a first blower 12, and a second blower 13. The air inlets of the combustion-supporting fan 11, the first blower 12, and the second blower 13 are respectively connected to the first heat exchanger 601, the second heat exchanger 701, and the third heat exchanger 801. The air outlet of the combustion-supporting fan 11 is respectively connected to the air guide wall 501 in the microwave magnetization roasting vertical furnace 5 and the third wind hood 401 in the oxidation exothermic vertical furnace 4 through a pipeline. The air outlets of the first blower 12 and the second blower 13 are respectively connected to the second wind hood 301 in the preheating vertical furnace 3 and the first wind hood 203 in the drying vertical furnace 2.

[0024] The finished product processing mechanism includes a gear roller unloader 901 arranged in the unloading vertical furnace 9, and also includes a scale plate machine 14 arranged in the water quenching tank 10. The end of the scale plate machine 14 is connected to a ball mill 15, and the discharge port of the ball mill 15 is provided with a magnetic separator 16.

[0025] A dust collector 20 is provided between the desulfurization tower 21 and the third heat exchanger 19 . The inlet of the dust collector 20 is connected to the outlet of the third heat exchanger 19 , and the outlet of the dust collector 20 is connected to the inlet of the desulfurization tower 21 .

[0026] An induced draft fan 22 is provided at the top of the desulfurization tower 21 , and a chimney 23 is provided on the induced draft fan 22 .

[0027] A method for using a siderite microwave magnetization roasting device comprises the following steps: S1: firstly crush the siderite into small pieces of 10-30 mm, and put the crushed siderite and additives into the feeding belt conveyor 1 in proportion, and then the siderite and additives are transported by the feeding belt conveyor 1 and enter the drying shaft furnace 2, the mass ratio of the siderite and additives is 10:0.5 to 10:1, and the additives are solid materials with certain calorific value and low ignition point, such as straw, wheat straw, and dried biochemical sludge; S2: The siderite and additives are dried in the drying vertical furnace 2 at a drying temperature of 100-150°C. The heat comes from two parts: one part is the hot air moving upward in the preheating vertical furnace 3; the other part is the room temperature air heated to 50-60°C by the third heat exchanger 19, and then heated to 300-350°C by the third heat exchanger 801, and then blown into the first hood 203 by the second blower 13 and evenly dispersed; S3: Siderite and additives are preheated to above 300°C in the preheating vertical furnace 3. The heat comes from two parts: one part is the hot air moving upward in the oxidation exothermic vertical furnace 4; the other part is the room temperature air heated to 80-90°C by the second heat exchanger 18, and then heated to 400-450°C by the second heat exchanger 701, and then blown into the second hood 301 by the first blower 12 and evenly dispersed; S4: Siderite and additives are preheated to above 450°C in the oxidation exothermic vertical furnace 4. The heat comes from four parts: the first part is the hot air moving upward in the microwave magnetization roasting vertical furnace 5; the second part is the hot air generated by the CO oxidation exothermic in the air guide wall 501 moving upward; the third part is the oxidation reaction of the additives to release a large amount of heat; the fourth part is the room temperature air heated to 110-120°C by the first heat exchanger 17, and then heated to 500-550°C by the first heat exchanger 601, and then blown into the third air hood 401 by the combustion-supporting fan 11 and evenly dispersed; S5: The siderite is catalyzed by microwaves and heated to 600-700°C in the microwave magnetization roasting shaft furnace 5, the siderite is rapidly decomposed, and the generated CO and CO2 gases penetrate into the air guide wall 501, wherein the CO gas undergoes an oxidation reaction in the air guide wall 501, releases heat and moves upward, preheating the siderite in the shaft furnace above it; S6: The decomposed iron ore is cooled to 250-300°C by the first slow cooling vertical furnace 6, the second slow cooling vertical furnace 7, and the third slow cooling vertical furnace 8, and then discharged into the water of the water quenching tank 10 by the toothed roller unloader 901 for oxygen-free water quenching. The iron ore after water quenching is scraped out from the water quenching tank 10 by the scale machine 14, and then ball-milled by the ball mill 15, and then Fe3O4 is selected by the magnetic separator 16; S7: The generated flue gas is cooled to below 100°C after heat exchange in the first heat exchanger 17, the second heat exchanger 18 and the third heat exchanger 19, and then passes through the dust collector 20 to remove particulate matter, and then passes through the desulfurization tower 21 to remove SO2 in the flue gas, and finally is blown into the chimney 23 by the induced draft fan 22 to meet the emission standards.

[0028] The working principle of the present invention is as follows: the combustion-supporting fan 11, the first blower 12 and the second blower 13 are turned on, and negative pressure is generated at the air inlets of the three, and the air from the outside is extracted through the pipelines respectively, that is, the air at normal temperature from the outside passes through the first heat exchanger 17, the second heat exchanger 18 and the third heat exchanger 19 respectively and enters the first heat exchanger 601 of the first slow cooling vertical furnace 6, the second heat exchanger 701 of the second slow cooling vertical furnace 7 and the third heat exchanger 801 of the third slow cooling vertical furnace 8. After the first heat exchanger 601, the second heat exchanger 701 and the third heat exchanger 801 heat the air in the corresponding pipelines to 500-550°C, 400-450°C and 300-350°C respectively, the air is blown to the next stage through the corresponding combustion-supporting fan 11, the first blower 12 and the second blower 13; The combustion-supporting blower 11 blows the heated gas to the air guide wall 501 in the microwave magnetization roasting vertical furnace 5 and the third wind cap 401 in the oxidation exothermic vertical furnace 4 through the pipeline, so as to uniformly heat the materials in the microwave magnetization roasting vertical furnace 5 and the oxidation exothermic vertical furnace 4. Similarly, the first blower 12 and the second blower 13 respectively heat the materials in the preheating vertical furnace 3 and the drying vertical furnace 2 by passing the hot gas into the second wind cap 301 and the first wind cap 203 respectively. In this process, due to the large mass and density of the siderite and additives, they will continue to fall to the lower vertical furnace after continuous heating, and the density of the heated gas is less than that of the air at room temperature. With the help of the fan, the gas is finally discharged from the exhaust port 201 of the drying vertical furnace 2. The discharged hot gas is sucked by the negative pressure of the combustion-supporting fan 11, the first blower 12, and the second blower 13 and guided by the pipeline, and then passes through the first heat exchanger 17, the second heat exchanger 18, and the third heat exchanger 19 in turn, and preliminarily heats the air at room temperature inside. Finally, the air temperature in the pipeline between the first heat exchanger 17 and the first slow cooling vertical furnace 6 is 110-120°C, the air temperature in the pipeline between the second heat exchanger 18 and the second slow cooling vertical furnace 7 is 80-90°C, and the air temperature in the pipeline between the third heat exchanger 19 and the third slow cooling vertical furnace 8 is 50-60°C, which reduces the energy consumption of the first heat exchanger 17, the second heat exchanger 18, and the third heat exchanger 19 to heat to the corresponding temperature respectively. At the same time, during the heating process of the microwave heater 502 in the microwave magnetization roasting vertical furnace 5, the hot gas generated by the oxidation heat release of CO in the air guide wall 501 will move upward, and the oxidation reaction of the additive will release a large amount of heat, which will further provide heat to the vertical furnace located above it, and the thermal energy will be comprehensively utilized, which greatly saves energy consumption. According to tests by technical personnel in the field, the energy consumption per ton of processing is reduced to less than 100 degrees of electricity, which greatly reduces the production cost. In addition, the use of microwaves for auxiliary catalytic heating has a good magnetization roasting effect, and the iron grade of siderite is increased from 40-43% to 62-65%, which greatly accelerates the decomposition time of siderite and improves the production capacity. At the same time, straw, wheat straw, biochemical sludge, etc. are fully utilized as fuel in the production process, which contributes to the comprehensive utilization of resources. The decomposed iron ore is cooled to 250-300°C by the first slow cooling vertical furnace 6, the second slow cooling vertical furnace 7, and the third slow cooling vertical furnace 8, and then discharged into the water of the water quenching tank 10 by the toothed roller unloader 901 for oxygen-free water quenching. The water-quenched iron ore is scraped out of the water quenching tank 10 by the scale machine 14, and then ball-milled by the ball mill 15, and then the Fe3O4 is selected by the magnetic separator 16; The generated flue gas is cooled to below 100°C after heat exchange in the first heat exchanger 17, the second heat exchanger 18 and the third heat exchanger 19, and then passes through the dust collector 20 to remove particulate matter, and then passes through the desulfurization tower 21 to remove SO2 in the flue gas, and finally is blown into the chimney 23 by the induced draft fan 22 to meet the emission standards.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microwave magnetization roasting device for siderite, comprising a feeding belt conveyor (1), a microwave magnetization roasting vertical furnace (5) and a desulfurization tower (21), wherein the microwave magnetization roasting vertical furnace (5) is connected to an oxidation exothermic vertical furnace (4) at its top, the oxidation exothermic vertical furnace (4) is connected to a preheating vertical furnace (3) at its top, the preheating vertical furnace (3) is connected to a drying vertical furnace (2) at its top, the drying vertical furnace (2) is connected to the feeding belt conveyor (1) and is used for preliminarily drying the siderite conveyed by the feeding belt conveyor (1), characterized in that: The invention also comprises a first slow cooling vertical furnace (6) connected to the bottom end of the microwave magnetization vertical furnace, the bottom end of the first slow cooling vertical furnace (6) is connected to a second slow cooling vertical furnace (7), the top end of the second slow cooling vertical furnace (7) is connected to the first slow cooling vertical furnace (6), and the bottom end is connected to a third slow cooling vertical furnace (8), the top end of the third slow cooling vertical furnace (8) is connected to the bottom end of the second slow cooling vertical furnace (7), and the bottom end is connected to a discharge vertical furnace (9), the top end of the discharge vertical furnace (9) is connected to the bottom end of the third slow cooling vertical furnace (8), and the bottom end is connected to a water quenching tank (10), and the water quenching tank (10) ) is provided with heat exchange coils (1001), and the distribution state is as follows: the drying vertical furnace (2), the preheating vertical furnace (3), the oxidation exothermic vertical furnace (4), the microwave magnetization roasting vertical furnace (5), the first slow cooling vertical furnace (6), the second slow cooling vertical furnace (7), the third slow cooling vertical furnace (8), the unloading vertical furnace (9), and the water quenching tank (10) are connected in series and sealed from top to bottom, and the siderite moves from top to bottom by gravity, and the hot gas heated by the heat exchange coils (1001) in the water quenching tank (10) moves from bottom to top and is discharged from the drying vertical furnace (2); It also includes a waste heat transfer mechanism connected to the desulfurization tower (21), the drying vertical furnace (2), the preheating vertical furnace (3), the oxidation exothermic vertical furnace (4), the microwave magnetization roasting vertical furnace (5), the first slow cooling vertical furnace (6), the second slow cooling vertical furnace (7), and the third slow cooling vertical furnace (8), and a finished product processing mechanism installed on the water quenching tank (10), wherein the waste heat transfer mechanism utilizes the heat energy in the components connected thereto to perform corresponding thermal processing on the siderite, and the finished product processing mechanism performs ball milling and screening on the preliminarily processed siderite to convert it into iron concentrate.

2. The microwave magnetization roasting device for siderite according to claim 1, characterized in that: The microwave magnetization roasting vertical furnace (5) is provided with an air guide wall (501), and a microwave heater (502) is provided on the outer wall. The air guide wall (501) is evenly arranged with air holes. The microwave heater (502) provides microwave energy for the microwave magnetization roasting vertical furnace (5). The microwave energy evenly heats the siderite and catalyzes a decomposition reaction.

3. The microwave magnetization roasting device for siderite according to claim 2, characterized in that: An exhaust port (201) is provided at the top of the drying vertical furnace (2), a feed port (202) is provided on the drying vertical furnace (2), the feed port (202) is located at the discharge end of the feed belt conveyor (1), and a first air hood (203) is provided in the drying vertical furnace (2), the first air hood (203) evenly disperses the hot air in the drying vertical furnace (2).

4. The microwave magnetization roasting device for siderite according to claim 3, characterized in that: The preheating vertical furnace (3) is provided with a second hood (301), which has the function of evenly dispersing hot air. This part of the hot air comes from the second slow cooling vertical furnace (7) and is used to preheat the mixture of siderite and additives in this section.

5. The microwave magnetization roasting device for siderite according to claim 4, characterized in that: The oxidation exothermic vertical furnace (4) is provided with a third hood (401), and the third hood (401) has the function of evenly dispersing hot air. This portion of hot air comes from the first slow cooling vertical furnace (6), and the additive is burned and released in this section to heat the siderite.

6. The microwave magnetization roasting device for siderite according to claim 5, characterized in that: The waste heat transfer mechanism comprises a first heat exchanger (601), a second heat exchanger (701), and a third heat exchanger (801) which are respectively arranged in a first slow cooling vertical furnace (6), a second slow cooling vertical furnace (7), and a third slow cooling vertical furnace (8); the first heat exchanger (601), the second heat exchanger (701), and the third heat exchanger (801) are all made of heat-conducting metal materials; It also includes a first heat exchanger (17), a second heat exchanger (18), and a third heat exchanger (19) arranged on one side of the first slow cooling vertical furnace (6), the second slow cooling vertical furnace (7), and the third slow cooling vertical furnace (8); the first heat exchanger (17), the second heat exchanger (18), and the third heat exchanger (19) are respectively connected to one side of the first heat exchanger (601), the second heat exchanger (701), and the third heat exchanger (801) through pipelines, and the three are interconnected and distributed in a straight line; the exhaust port (201) on the drying vertical furnace (2) is connected to the inlet end of the first heat exchanger (17), and the outlet end of the third heat exchanger (19) is connected to the desulfurization tower (21); The invention also comprises a combustion-supporting fan (11), a first blower (12), and a second blower (13); the air inlets of the combustion-supporting fan (11), the first blower (12), and the second blower (13) are respectively connected to the first heat exchanger (601), the second heat exchanger (701), and the third heat exchanger (801); the air outlet of the combustion-supporting fan (11) is respectively connected to the air guide wall (501) in the microwave magnetization roasting vertical furnace (5) and the third air hood (401) in the oxidation exothermic vertical furnace (4) through a pipeline; the air outlets of the first blower (12) and the second blower (13) are respectively connected to the second air hood (301) in the preheating vertical furnace (3) and the first air hood (203) in the drying vertical furnace (2).

7. The microwave magnetization roasting device for siderite according to claim 6, characterized in that: The finished product processing mechanism comprises a toothed roller discharger (901) arranged in a discharge vertical furnace (9), and also comprises a scale plate machine (14) arranged in a water quenching tank (10), the end of the scale plate machine (14) is connected to a ball mill (15), and the discharge port of the ball mill (15) is provided with a magnetic separator (16).

8. The microwave magnetization roasting device for siderite according to claim 7, characterized in that: A dust collector (20) is provided between the desulfurization tower (21) and the third heat exchanger (19); the inlet of the dust collector (20) is connected to the outlet of the third heat exchanger (19), and the outlet is connected to the inlet of the desulfurization tower (21).

9. The microwave magnetization roasting device for siderite according to claim 8, characterized in that: An induced draft fan (22) is provided at the top of the desulfurization tower (21), and a chimney (23) is provided on the induced draft fan (22).

10. A method, characterized in that: The roasting method applicable to the microwave magnetization roasting device of siderite as described in claim 9 above comprises the following steps: S1: firstly crush the siderite into small pieces of 10-30 mm, and feed the additive and the crushed siderite into the feeding belt conveyor (1) in proportion, and then the siderite enters the drying vertical furnace (2) after being transmitted by the feeding belt conveyor (1), and the mass ratio of the siderite to the additive is 10:0.5 to 10:1, and the additive is straw, wheat straw, and dried biochemical sludge, and the additive is a solid with a certain calorific value and a low ignition point; S2: The siderite is dried in the drying vertical furnace (2) at a drying temperature of 100-150°C. The heat comes from two parts: one part is the hot air moving upward in the preheating vertical furnace (3); the other part is the room temperature air heated to 50-60°C by the third heat exchanger (19), then heated to 300-350°C by the third heat exchanger (801), and then blown into the first air hood (203) by the second blower (13) and evenly dispersed; S3: The siderite is preheated to above 300°C in the preheating vertical furnace (3). The heat comes from two parts: one part is the hot air moving upward in the oxidation exothermic vertical furnace (4); the other part is the room temperature air heated to 80-90°C by the second heat exchanger (18), and then heated to 400-450°C by the second heat exchanger (701), and then blown into the second hood (301) by the first blower (12) and evenly dispersed; S4: The siderite is preheated to above 450°C in the oxidation exothermic vertical furnace (4). The heat comes from four parts: the first part is the hot air moving upward in the microwave magnetization roasting vertical furnace (5); the second part is the hot air generated by the CO oxidation exothermic in the air guide wall (501) moving upward; the third part is the oxidation reaction of the additives to release a large amount of heat; the fourth part is the room temperature air heated to 110-120°C by the first heat exchanger (17), and then heated to 500-550°C by the first heat exchanger (601), and then blown into the third air hood (401) by the combustion-supporting fan (11) and evenly dispersed; S5: the siderite is catalyzed by microwaves and heated to 600-700°C in the microwave magnetization roasting vertical furnace (5), the siderite is rapidly decomposed, and the generated CO and CO2 gases penetrate into the air guide wall (501), wherein the CO gas undergoes an oxidation reaction in the air guide wall (501), releases heat and moves upward, preheating the siderite in the vertical furnace above it; S6: the decomposed iron ore is cooled to 250-300°C in a first slow cooling vertical furnace (6), a second slow cooling vertical furnace (7), and a third slow cooling vertical furnace (8), and then discharged into water in a water quenching tank (10) by a toothed roller unloader (901) for oxygen-free water quenching. The quenched iron ore is scraped out of the water quenching tank (10) by a scale plate machine (14), and then ball milled in a ball mill (15), and then Fe3O4 is separated by a magnetic separator (16); S7: The generated flue gas is cooled to below 100°C after heat exchange in the first heat exchanger (17), the second heat exchanger (18), and the third heat exchanger (19). The flue gas is then passed through a dust collector (20) to remove particulate matter. The flue gas is then passed through a desulfurization tower (21) to remove SO2 from the flue gas. The flue gas is finally blown into a chimney (23) by an induced draft fan (22) to meet emission standards.

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