A four-heat low-carbon sintering reduction kiln

Abstract

The present invention belongs to the technical field of mineral material smelting process, and discloses a four-heat type low-carbon sintering reduction kiln, comprising two groups of silos arranged on a site, which are connected to a mixing tower by pipes; the mixing tower consists of a three-layer building structure; the materials are evenly stirred and transported to an electromagnetic heating kiln, in which an electromagnetic rotary device is provided; a stewing pot is provided at the lower end of the electromagnetic heating kiln, which is connected to the furnace by a conveyor, and the top of the furnace is output to a slag pot and a ladle pot respectively; a pipe is provided on the side of the electromagnetic heating kiln to be connected to a heat exchanger, and a pipe is used to connect the heat exchanger to a washing tower, and two groups of washing towers are provided; a water cooling and power supply system is provided in the site below the electromagnetic heating kiln; the present invention can realize the integration of drying, roasting, reduction and other processes, ensure the uniformity of the materials, and make the roasting products loose and porous; the present invention does not require mechanical ventilation, can significantly improve the pre-reduction degree of metal oxides, and at the same time realize efficient use of heat.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral smelting technology, and in particular relates to a four-heat type low-carbon sintering reduction kiln. Background Art

[0002] At present, traditional ore is dried in a drying kiln to a moisture content of less than 25%, and then added to a rotary kiln after being mixed with a reducing agent in a certain proportion. The burner makes the coal powder burn in the air to provide a heat source for further drying, roasting and pre-reduction of the ore. After the reaction, the roasted sand is added to the submerged arc furnace through a material tank trolley for smelting and reduction.

[0003] The traditional ore roasting process requires two pieces of equipment: a drying kiln and a rotary kiln. The heat used in the drying kiln is typically generated by either waste gases from the kiln smelting process or by the combustion of blended coal. The former, however, suffers from low-temperature waste heat recovery, resulting in poor drying results. The latter, on the other hand, requires fuel, increasing costs. Furthermore, the dried ore is susceptible to ambient moisture levels during the batching phase, resulting in high moisture content entering the kiln.

[0004] During the production process, the heat source is the high-temperature airflow generated by the combustion of pulverized coal sprayed by the burner in the air. In order to ensure heat exchange efficiency and temperature uniformity, the hot air flow and the material must flow through the entire kiln in the opposite direction under mechanical ventilation conditions. The large amount of air brought in by ventilation takes away a large amount of heat. Moreover, since most of the pulverized coal reacts with oxygen in the air to release heat, the five-point reduction degree of the metal oxides in the ore is low. At the same time, due to the convection heat exchange working mechanism of the rotary kiln, the temperature in the kiln tends to change from high to low with the direction of the airflow. The high-temperature zone is prone to kiln skin and ore burnout, and the reducing effect of the volatile matter in the reducing agent in the low-temperature zone cannot be exerted, resulting in energy waste.

[0005] Through the above analysis, the problems and defects of the existing technology are as follows:

[0006] Traditional ore smelting processes involve lengthy processes, high operating temperatures, high energy consumption, numerous and extensive pollution, and low utilization of waste heat from exhaust gases. Moisture and harmful substances in the raw materials significantly impact smelting results and costs. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention provides a four-heat type low-carbon sintering reduction kiln.

[0008] The present invention is implemented as follows: a four-heat low-carbon sintering reduction kiln includes two groups of silos set up on the site, and the silos are connected to the mixing tower by pipes; the mixing tower consists of a three-story building structure, the first floor is overhead, the second floor is a batching station, and the third floor is a processing room; the materials are evenly stirred and transported to the electromagnetic heating kiln, and an electromagnetic rotating device is provided in the electromagnetic heating kiln; a stewing pot is provided at the lower end of the electromagnetic heating kiln and is connected to the furnace by a conveyor, and the top of the furnace is output to a slag pot and a ladle pot respectively; a pipe is provided on the side of the electromagnetic heating kiln and is connected to a heat exchanger, and the heat exchanger and the washing tower are connected by a pipe, and two groups of washing towers are provided; a water cooling and power supply system is provided in the site below the electromagnetic heating kiln.

[0009] Furthermore, the silo is a circular tower silo, two groups of which are set up in the site to store raw materials and auxiliary materials (reducing agents) respectively. They are connected to the mixing tower by pipelines, and the materials can be transported to the mixing tower in turn.

[0010] Furthermore, the mixing tower is a three-story building structure, which includes an overhead floor, a batching station on the second floor, and a processing room on the third floor, which can mix and knead the ore and the reducing agent and extrude them into shaped ore.

[0011] Furthermore, the electromagnetic heating kiln is arranged on the second floor, and an electromagnetic rotating device is provided inside, which can realize four stages of reaction conditions with different temperature reaction sections.

[0012] Furthermore, the stewing pot is arranged at the lower part of the electromagnetic heating kiln, and the stewing pot can be stewed.

[0013] Furthermore, the furnace and the stewing pot are connected by a conveyor, which transports the calcined sand to the top of the furnace, melts the molten metal, and separates the slag and the solution.

[0014] Furthermore, the slag ladle tank is used to store the slag ladle siphoned out by the negative pressure of the furnace; and the ladle tank is used to store the steel ladle siphoned out by the negative pressure of the furnace.

[0015] Furthermore, the heat exchanger is connected to the side wall pipe of the electromagnetic heating kiln, and can recycle the heat in the tail gas generated during the reaction.

[0016] Furthermore, the washing tower is connected to the heat exchanger by a pipeline, and the tail gas is treated by a water circulation mud filtering method.

[0017] Furthermore, a water cooling and power supply system is provided at the bottom of the electromagnetic heating kiln, which includes water cooling (for kiln), water cooling (for power supply), motor power supply, and medium frequency power supply-cooler to dissipate heat and provide power for the entire device.

[0018] Furthermore, all the above components are arranged in four groups in parallel on the site, which can improve work efficiency.

[0019] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0020] (1) Using electromagnetic heating kilns, drying, roasting, reduction, and semi-melting are integrated to control the temperature of the reaction zone and achieve efficient reduction of metal oxides. This avoids the formation of kiln skin, ore burnout, and high-temperature nitrogen oxides caused by the concentration of high-temperature areas.

[0021] (2) Internal carbon smelting: the reducing agent and ore are integrated and mixed to form agglomerates before entering the kiln for reaction to ensure the uniformity of the material. At the same time, the volatile matter of the reducing agent is released under high temperature conditions and the pores generated by the reduction of metal oxides make the roasted product loose and porous, which is conducive to subsequent smelting.

[0022] (3) No mechanical ventilation is required. During the production process, there is no need to introduce air to assist in the combustion of pulverized coal and convective heat exchange. Most of the oxygen in the reducing agent reaction comes from the metal oxides, which significantly improves the pre-reduction degree of the metal oxides. At the same time, it avoids a large amount of waste gas from taking away heat, thereby achieving efficient use of heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the layout of a four-heat low-carbon sintering reduction kiln provided in an embodiment of the present invention.

[0024] Figure 2 It is a schematic structural diagram of a four-heat low-carbon sintering reduction kiln provided in an embodiment of the present invention.

[0025] Figure 3 It is a schematic diagram of the working process of the four-heat low-carbon sintering reduction kiln provided in an embodiment of the present invention.

[0026] In the figure: 1. Silo; 2. Mixing tower; 2-1. First floor; 2-2. Second floor bottom plate; 2-3. Batching station; 2-4. Third floor floor; 2-5. Processing room; 2-6. Third floor roof; 3. Electromagnetic heating kiln; 4. Electromagnetic rotary device; 5. Heat exchanger; 6. Pipeline; 7. Washing tower; 8. Water cooling (for kiln); 9. Water cooling (for power supply); 10. Medium frequency power supply-cooler; 11. Motor power supply; 12. Stewing tank; 13. Conveyor; 14. Furnace; 15. Slag ladle tank; 16. Ladle tank. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] like Figures 1 to 3As shown, the four-heat low-carbon sintering reduction kiln provided in an embodiment of the present invention has a circular tower warehouse, two groups of which are arranged in the site to store raw materials and auxiliary materials (reducing agents) respectively, and are connected to the mixing tower by a pipeline, so that the materials can be transported to the mixing tower in turn.

[0029] According to the layout diagram, structure diagram and workflow diagram of the four-heat low-carbon sintering reduction kiln, the following are the detailed connection relationships and working principles of each component:

[0030] Silo 1: stores raw materials and is connected to mixing tower 2 through a pipeline.

[0031] Mixing Tower 2: Consists of a three-story structure. The first floor (2-1) is elevated, the second floor (2-2) houses the batching station (2-3), the third floor (2-4) houses the intermediate processing room (2-5), and the third floor (2-6) covers the top. The mixing tower is responsible for mixing and stirring the raw materials.

[0032] Electromagnetic heating kiln 3: receives the mixed raw materials and heats and stirs them through the electromagnetic rotary device 4. A stewing pot 12 is provided at the lower end of the electromagnetic heating kiln and is connected to a furnace 14.

[0033] Electromagnetic rotary device 4: installed inside the electromagnetic heating kiln 3, used for heating and stirring raw materials.

[0034] Heat exchanger 5: connected to the pipe 6 on the side of the electromagnetic heating kiln 3, used to recover the heat in the kiln.

[0035] Scrubber 7: It is connected to the heat exchanger 5 by a pipeline and is responsible for treating the flue gas.

[0036] Water cooling (for kiln) 8 and water cooling (for power supply) 9: located below the electromagnetic heating kiln 3, used for cooling the kiln body and the power supply respectively.

[0037] Medium frequency power supply-cooler 10 and motor power supply 11: provide power for the electromagnetic rotating device 4 and the conveyor 13.

[0038] Conveyor 13: transports the raw materials in the stewing pot 12 to the furnace 14.

[0039] Furnace 14: responsible for melting the raw materials, and outputting the top to the slag pot 15 and the ladle pot 16 respectively.

[0040] The working principle of the four-heat low-carbon sintering reduction kiln provided in the embodiment of the present invention is as follows:

[0041] The raw materials are transported from the silo 1 to the mixing tower 2 and mixed and stirred at the batching station 2-3.

[0042] The mixed raw materials enter the electromagnetic heating kiln 3 and are heated and stirred by the electromagnetic rotary device 4.

[0043] The heated raw materials are conveyed to the furnace 14 via a conveyor 13 for smelting.

[0044] The flue gas generated at the top of the furnace 14 enters the heat exchanger 5 through the pipe 6 for heat recovery, and then enters the scrubbing tower 7 through the pipe for treatment.

[0045] The smelted slag and molten steel flow into the slag ladle pot 15 and the ladle pot 16 respectively.

[0046] During the entire working process, the equipment maintains stable operation through the water cooling system and power supply system.

[0047] Preferably, the mixing tower is a three-story building structure, including an overhead floor, a batching station on the second floor, and a processing room on the third floor, which can mix and knead the ore and the reducing agent and extrude them into shaped ore.

[0048] Preferably, the electromagnetic heating kiln is arranged on the second floor, and an electromagnetic rotating device is provided inside, which can realize four stages of reaction conditions with different temperature reaction sections.

[0049] Preferably, the stewing pot is arranged at the lower part of the electromagnetic heating kiln, and the stewing pot can be stewed.

[0050] Preferably, the furnace and the stewing pot are connected by a conveyor, which transports the calcined sand to the top of the furnace, melts the molten metal, and separates the slag and the solution.

[0051] Preferably, the slag ladle tank is used to store the slag ladle siphoned out by the negative pressure of the furnace; and the ladle tank is used to store the steel ladle siphoned out by the negative pressure of the furnace.

[0052] Preferably, the heat exchanger is connected to the side wall pipe of the electromagnetic heating kiln, so as to be able to recycle the heat in the tail gas generated during the reaction.

[0053] Preferably, the washing tower is connected to the heat exchanger by a pipeline, and the tail gas is treated by a water circulation and mud filtering method.

[0054] Preferably, a water cooling and power supply system is provided at the bottom of the electromagnetic heating kiln, which respectively includes water cooling (for the kiln), water cooling (for the power supply), motor power supply, and medium frequency power supply-cooler to dissipate heat and provide power for the entire device.

[0055] Preferably, all the above components are arranged in four groups in parallel on the site to improve operating efficiency.

[0056] like Figure 3 As shown, the specific workflow of the present invention is:

[0057] (1) The raw materials and auxiliary materials (reducing agent) are transported into the mixing tower, the ore is crushed and added to the vacuum mixer with the reducing agent in a certain proportion, mixed and kneaded, and then extruded into a shaped ore with a certain particle size and strength.

[0058] (2) The ore is added to the electromagnetic and reacted under four different temperature reaction sections. An air lock valve and a one-way exhaust pipe are installed between each section to control the inflow of external air, and an exhaust valve is installed to control the gas and harmful volatiles. The tail gas generated after the first kiln is partially treated by the scrubber and then discharged. The remaining tail gas is treated by the device and then deeply reduced with high-temperature plasma.

[0059] Each temperature reaction section uses cooling water circulation to cool down and is powered by electricity. The different temperature reaction sections are:

[0060] The first stage: heating temperature 400-600℃, mainly used for drying materials and precipitation of volatile matter;

[0061] The second stage: Heating temperature is 500-700℃. The main reactions are the cracking of hydrocarbons in the volatile matter to generate hydrogen and free carbon, and the reduction reaction of the cracking products hydrogen and carbon to metal oxides.

[0062] The third stage: Heating temperature is 600-850℃, the main reaction is the reduction reaction of the free carbon of the cracking product to the metal oxide, and the material temperature rises.

[0063] (3) The roasted sand at 850°C after roasting and pre-reduction is transported to a stewing tank, powered by an external heat source, and transported to a smelting furnace after stewing. The tail gas treated by the tail gas utilization device is used as a deep reduction with high-temperature plasma and semi-melted into a metallurgical furnace to smelt the molten metal. The smelting furnace is subjected to negative pressure siphoning to separate the slag and the solution. The slag is transported to a slag ladle tank, and the molten metal liquid is blown through a negative pressure flow channel pool to form a solution ladle, which is stored in a ladle tank.

[0064] (4) Simultaneously with step 3, the heat in the tail gas is collected by a heat exchanger and supplied to the batching station. The tail gas is then processed and discharged through a washing tower in the form of water circulation and mud filtration.

[0065] This invention utilizes a sintering and reduction system that utilizes multiple heat sources, integrating drying, anaerobic sintering, and reduction into a smelting process. Through batching, homogenization, and vacuum preparation, the ore is dried, preheated, simmered, reduced, and melted before being added to a metallurgical furnace for smelting, achieving an ultra-low-carbon smelting process. This invention manages the smelting environment, characteristics, and elements required by the smelting process in a segmented manner, providing the corresponding environmental and characteristic conditions. This allows for automation of the entire process and fluidization to produce reduced molten metal.

[0066] The four-heat, low-carbon sintering and reduction kiln provided by the present invention is an innovative and environmentally friendly industrial furnace. It utilizes advanced sintering and reduction technology to achieve high-efficiency, low-carbon, and environmentally friendly production goals. The following are the technical effects and advantages of this sintering and reduction kiln:

[0067] 1.) Efficient energy utilization: Through electromagnetic heating technology, the raw materials can be quickly heated and evenly stirred, which improves energy utilization efficiency.

[0068] 2.) Low carbon emissions: The four-heat design, energy recovery and reuse reduce carbon emissions and energy consumption.

[0069] 3.) Environmental protection: By connecting with the scrubbing tower, the flue gas can be treated and purified, reducing pollution to the environment.

[0070] 4.) Compact structure: The three-layer building structure design saves site space and facilitates equipment installation and maintenance.

[0071] 5.) High degree of automation: The use of automated conveyors and pipeline connections realizes automatic transportation and processing of materials, reducing labor costs.

[0072] 6.) Safe and reliable: The area below the electromagnetic heating kiln is equipped with a water cooling and power supply system to ensure the safe operation of the equipment.

[0073] In summary, this four-heat low-carbon sintering reduction kiln has obvious technical advantages and environmental protection value in actual production, and is expected to be widely used in various industrial furnaces and kiln equipment.

[0074] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A four-heat low-carbon sintering reduction kiln, characterized in that: It includes two sets of silos installed on the site, which are connected to the mixing tower by pipes. The mixing tower consists of a three-story building structure, with the first floor elevated, the second floor serving as the batching station, and the third floor serving as the intermediate processing room. After being evenly mixed, the materials are transported to the electromagnetic heating kiln, which is equipped with an electromagnetic rotary device. A stewing tank is installed at the lower end of the electromagnetic heating kiln, which is connected to the furnace by a conveyor. The top of the furnace outputs to the slag pot and the ladle pot respectively. Pipes are installed on the side of the electromagnetic heating kiln to connect to the heat exchanger, which is connected to the washing tower by pipes. There are two sets of washing towers. The site below the electromagnetic heating kiln is equipped with a water cooling and power supply system. The silos are circular tower silos, with two groups set up in the site to store raw materials and auxiliary materials respectively. They are connected to the mixing tower by pipes, and the materials can be transported to the mixing tower in sequence; The mixing tower is a three-story building structure, with the first floor being an overhead floor, the second floor being a batching station, and the third floor being a processing room, which can mix and knead the ore and the reducing agent and extrude them into shaped ore; The electromagnetic heating kiln is arranged on the second floor and is provided with an electromagnetic rotating device inside. The electromagnetic rotating device can realize four sections of reaction conditions with different temperature reaction sections.

2. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The stewing pot is arranged at the lower part of the electromagnetic heating kiln, and can be used for stewing.

3. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The furnace and the stewing pot are connected by a conveyor, which transports the calcined sand to the top of the furnace, melts the molten metal, and separates the slag and the solution.

4. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The slag ladle tank is used to store the slag ladle siphoned out by the negative pressure of the furnace; the ladle tank is used to store the steel ladle siphoned out by the negative pressure of the furnace.

5. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The heat exchanger is connected to the side wall pipe of the electromagnetic heating kiln and can recycle the heat in the tail gas generated during the reaction.

6. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The washing tower is connected to the heat exchanger by a pipeline, and the tail gas is treated by a water circulation mud filtering method.

7. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: The lower part of the electromagnetic heating kiln is provided with a water cooling and power supply system, which includes water cooling (for the kiln), water cooling (for the power supply), motor power supply, and medium frequency power supply-cooler, which dissipate heat and provide power for the entire device.

8. The four-heat low-carbon sintering reduction kiln according to claim 1, characterized in that: All of the above components are arranged in four groups in parallel on the site, which can improve work efficiency.

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