Combined type high-temperature roasting rotary kiln unit
Through the design of the composite high-temperature roasting rotary kiln unit, the problems of poor material flowability and unused roasting waste heat are solved, and efficient recycling of copper smelting slag flotation tailings are achieved, reducing production costs and extending equipment life.
Patent Information
- Application Number
- CN202421706437.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2025-09-05
- Estimated Expiration
- 2034-07-18
AI Technical Summary
When handling copper smelting slag flotation tailings, the existing integrated rotary kilns have poor material fluidity and difficult to partition temperature control, resulting in insufficient reaction and equipment damage, and the baking waste heat is not used, resulting in waste of energy.
The composite high-temperature roasting rotary kiln unit is adopted, including a preheated drying rotary kiln and a high-temperature reduction roasting rotary kiln, which are preheated and dried and high-temperature roasted, and the flue gas heat is recycled through the heat recovery system, and the kiln body structure is separated to reduce the use of refractory bricks and equipment burden.
It realizes full reaction of materials and efficient utilization of heat energy, reduces production costs, extends equipment life, improves operation rate, and meets process requirements.
Smart Images
Figure CN223307272U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of nonferrous metal smelting, and in particular relates to a composite high-temperature roasting rotary kiln unit. Background Art
[0002] The statements in this section are merely intended to provide background information related to the technical solution of the present application to aid understanding, and they do not necessarily constitute prior art with respect to the technical solution of the present application.
[0003] The tailings produced by copper smelting, after copper metal minerals are recovered through the beneficiation process, are primarily composed of iron and silicate minerals, with a certain amount of lead, zinc, and a small amount of copper, making them valuable for mineral resource recycling. Integrated rotary kilns are commonly used to recover valuable metals from copper smelting slag flotation tailings. The process is as follows: the copper smelting slag flotation tailings are fed into a reduction roaster for preheating and reduction roasting at a temperature of 1200°C-1280°C, using ordinary bituminous coal or coke as the reducing agent. High-temperature volatile minerals such as lead and zinc are recovered from the flue gas. The resulting fly ash can be used as a mixed concentrate of lead oxide and zinc. Iron is reduced to metallic iron and magnetic iron, and copper is converted into roasted sand in the form of metallic copper and copper sulfide. After cooling, the roasted sand is sent to the copper and iron recovery and separation process. However, the material is a powdery material with a small particle size, usually more than 90% of the material has a particle size of less than 0.038mm, and its fluidity in the roasting furnace is poor; in addition, the preheating and drying process and the high-temperature roasting process must be carried out in the same rotary kiln body, and the temperature of the preheating and drying process usually only needs to be less than 400°C. Therefore, the integrated rotary kiln is not easy to control the temperature by zone. When the temperature is too high, the material directly enters the high-temperature roasting process, which is prone to insufficient reaction. On the other hand, the rotary kiln body will be too long, and high-temperature roasting will damage the steel kiln body. Refractory bricks are usually required to be laid in the kiln body. If refractory bricks are laid throughout a larger and longer kiln body, it will cause a heavier weight, which is easy to cause damage to tugboats and other equipment; at the same time, the residual heat from roasting is not utilized, resulting in energy waste. Utility Model Content
[0004] In order to solve the problems existing in the integrated rotary kiln in the prior art, the utility model proposes a composite high-temperature roasting rotary kiln unit consisting of a preheating and drying rotary kiln, a high-temperature reduction roasting rotary kiln and a heat energy recovery system. The specific technical solution is as follows:
[0005] A composite high-temperature roasting rotary kiln unit includes a preheating drying rotary kiln, a high-temperature reduction roasting rotary kiln and a heat energy recovery system, wherein the preheating drying rotary kiln includes a preheating section feeding device, a preheating section kiln body, a preheating section discharging device and a preheating section heating spray gun in sequence, and a preheating section supporting wheel device, a preheating section rotating device and a preheating section blocking supporting wheel device are sequentially arranged outside the preheating section kiln body; the high-temperature reduction roasting rotary kiln includes a high-temperature roasting section feeding device, a high-temperature roasting section kiln body, a high-temperature roasting section discharging device and a high-temperature roasting section heating spray gun in sequence, and a heat insulation layer is provided inside the high-temperature roasting section kiln body, and a high-temperature roasting section supporting wheel device, a high-temperature roasting section rotating device, a high-temperature roasting section The heat energy recovery system includes a dust collecting device, an induced draft fan, a flue gas recycling nozzle, a flue gas recovery pipeline and a flue gas recycling pipeline, and the flue gas recycling nozzle is arranged at the inlet of the preheating section feeding device; the preheating section kiln body and the high-temperature roasting section kiln body are inclined, and the preheating section kiln body is located above the high-temperature roasting section kiln body, the preheating section discharging device is vertically connected to the high-temperature roasting section feeding device, and the tail of the high-temperature roasting section kiln body is a flue gas box, the outlet of the flue gas box is connected to the inlet of the dust collecting device via a flue gas recovery pipeline, the outlet of the dust collecting device is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the flue gas recycling nozzle via a flue gas recycling pipeline.
[0006] Furthermore, the composite high-temperature roasting rotary kiln unit also includes a plate conveyor, and the heat energy recovery system also includes a hot gas recovery hood. The plate conveyor is located below the high-temperature roasting section discharging device, and the hot gas recovery hood is covered above the plate conveyor. The outlet of the hot gas recovery hood is connected to the flue gas recycling pipeline via a pipeline.
[0007] Furthermore, the diameter of the preheating kiln body is smaller than that of the high-temperature roasting kiln body. Specifically, the diameter ratio of the preheating kiln body to the high-temperature roasting kiln body can be 1:1.5.
[0008] Furthermore, the inclination angle of the preheating kiln body with the horizontal plane is greater than the inclination angle of the high-temperature roasting kiln body with the horizontal plane. Preferably, the inclination angle of the preheating kiln body with the horizontal plane is 4.5°, and the inclination angle of the high-temperature roasting kiln body with the horizontal plane is 3.5°.
[0009] Furthermore, the rotating devices of the two-section kiln body are installed in the middle of the kiln body, the supporting wheel device is installed near the kiln tail, and the blocking supporting wheel device is installed near the kiln head.
[0010] Furthermore, the preheating section feeding device and the preheating section discharging device are both slidingly and sealingly connected to the preheating section kiln body, and the high-temperature roasting section feeding device and the high-temperature roasting section discharging device are both slidingly and sealingly connected to the high-temperature roasting section kiln body.
[0011] Furthermore, the preheating kiln body is made of boiler steel, the high-temperature roasting kiln body is also made of boiler steel, and a refractory brick layer is laid inside the heat insulation layer of the high-temperature roasting kiln body to prevent damage to the kiln body due to high temperature.
[0012] Furthermore, the preheating section heating lance is inserted horizontally into the preheating section kiln body through the preheating section discharge device, near the top of the preheating section kiln body; the high-temperature roasting section heating lance is inserted horizontally into the high-temperature roasting section kiln body through the high-temperature roasting section discharge device, near the top of the high-temperature roasting section kiln body. Specifically, the heating lance is inserted into the kiln body to a depth of 150-200 mm.
[0013] Furthermore, the flue gas recycling line near the flue gas recycling nozzle is equipped with multiple layers of screens with a pore size of 6-10 mm and triangular guide plates to reduce the flue gas flow rate while directing the flue gas to flow longitudinally along both sides of the kiln. Specifically, 4-6 layers of screens can be provided, and the flue gas recycling nozzle is inserted into the kiln to a depth of 150-200 mm. The screen pore size is preferably 8 mm.
[0014] Among them, the kiln tail refers to the higher end of the rotary kiln, and the kiln head refers to the lower part of the rotary kiln.
[0015] Compared with the prior art, the beneficial technical effects of the present invention are:
[0016] (1) The composite high-temperature roasting rotary kiln unit of the present invention is based on the characteristics of the roasting raw materials and the process characteristics of high-temperature roasting. The roasting kiln body is completely separated in structure according to the different temperatures of the roasting process, and a composite configuration is performed. The split design of the kiln body at both ends can reduce the size of the high-temperature roasting section kiln body, and there is no need to set a high-temperature resistant layer such as refractory bricks in the preheating and drying section kiln body, which saves costs and reduces the burden on devices such as tugboats;
[0017] (2) The inclined setting of the two sections of the kiln body and the upper and lower arrangement and vertical connection of the kiln body can facilitate the flow and transmission of powder materials. In addition, the inclination angle of the preheating section kiln body is greater than the inclination angle of the high-temperature roasting section kiln body, which is conducive to the smooth introduction of materials from the preheating section kiln body to the high-temperature roasting section kiln body, and will not be quickly discharged in the high-temperature roasting section kiln body. When the inclination angle becomes gentle, the flow speed can be slowed down, and the materials can fully react in the high-temperature roasting section kiln body;
[0018] (3) Both kiln sections are equipped with separate transmission devices and heating devices, which can effectively carry out the two processes of preheating and drying and high-temperature roasting, effectively avoiding the problem of insufficient reaction caused by high-temperature reduction without sufficient preheating and drying of the material;
[0019] (4) The composite unit simultaneously realizes the roasting of the material and the recycling of high-temperature hot gas. The high-temperature flue gas is recovered and used in the preheating and drying process. The heat recovery rate can be ≥40%. While efficiently and comprehensively recovering valuable metal elements such as copper, iron, lead, and zinc in the flotation tailings of copper smelting slag, the heat recovery and utilization are maximized to reduce production costs, reduce equipment maintenance rates, and improve equipment operation rates to meet process requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Schematic diagram of the structure of this utility model.
[0021] Among them, there are preheating section feeding device-1, preheating section kiln body-2, preheating section supporting roller device-3, preheating section rotating device-4, preheating section blocking roller device-5, preheating section discharging device-6, high-temperature roasting section feeding device-7, high-temperature roasting section kiln body-8, high-temperature roasting section supporting roller device-9, high-temperature roasting section rotating device-10, high-temperature roasting section blocking roller device-11, high-temperature roasting section discharging device-12, dust collecting device-13, induced draft fan-14, thermal insulation layer-15, high-temperature roasting section heating spray gun 16, preheating section heating spray gun-17, plate conveyor-18, hot gas recovery hood-19, and flue gas recycling nozzle-20. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following describes the composite high-temperature roasting rotary kiln unit of the present application in detail with reference to 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.
[0023] See also Figure 1The present embodiment is a composite high-temperature roasting rotary kiln unit comprising a preheating drying rotary kiln, a high-temperature reducing roasting rotary kiln, a plate conveyor 18 and a heat recovery system. The preheating drying rotary kiln comprises a preheating section feeding device 1, a preheating section kiln body 2, a preheating section discharging device 6 and a preheating section heating spray gun 17 in sequence. The preheating section kiln body 2 is made of boiler steel. A preheating section supporting roller device 3, a preheating section rotating device 4 and a preheating section blocking supporting roller device 5 are sequentially arranged outside the preheating section kiln body 2. The preheating section feeding device 1 and the preheating section discharging device 6 are both tightly slidably connected to the preheating section kiln body 2. Sealed connection; the high-temperature reduction roasting rotary kiln comprises a high-temperature roasting section feeding device 7, a high-temperature roasting section kiln body 8, a high-temperature roasting section discharging device 12 and a high-temperature roasting section heating spray gun 16 in sequence, the high-temperature roasting section kiln body 8 is made of boiler steel, and the inside of the insulation layer 15 of the high-temperature roasting section kiln body 8 is also paved with a refractory brick layer, and the high-temperature roasting section kiln body 8 is sequentially provided with a high-temperature roasting section supporting wheel device 9, a high-temperature roasting section rotating device 10, and a high-temperature roasting section blocking supporting wheel device 11, wherein the diameter ratio of the preheating section kiln body 2 to the high-temperature roasting section kiln body 8 can be 1:1.5, high temperature The roasting section feeding device 7 and the high-temperature roasting section discharging device 12 are both connected to the high-temperature roasting section kiln body 8 in a sliding and sealed manner; the heat energy recovery system includes a dust collecting device 13, an induced draft fan 14, a hot gas recovery hood 19, a flue gas recycling nozzle 20, and a flue gas recovery pipeline and a flue gas recycling pipeline. The flue gas recycling nozzle 20 is arranged at the entrance of the preheating section feeding device 1; wherein the inclination angle of the preheating section kiln body 2 to the horizontal plane is 4.5°, and the inclination angle of the high-temperature roasting section kiln body 8 to the horizontal plane is 3.5°, and the preheating section kiln body 2 is located above the high-temperature roasting section kiln body 8, and the preheating section kiln body 2 is located above the high-temperature roasting section kiln body 8. The section discharge device 6 is vertically connected to the high-temperature roasting section feeding device 7. The tail of the high-temperature roasting section kiln body 8 is a flue gas chamber. The flue gas chamber outlet is connected to the inlet of the dust collector 13 via a flue gas recovery pipeline. The outlet of the dust collector 13 is connected to the inlet of the induced draft fan 14. The outlet of the induced draft fan 14 is connected to the flue gas recycling nozzle 20 via a flue gas recycling pipeline. The plate conveyor 18 is located below the high-temperature roasting section discharge device 12. The hot gas recovery hood 19 is covered above the plate conveyor. The outlet of the hot gas recovery hood 19 is connected to the flue gas recycling pipeline via a pipeline. The heating spray guns are horizontally inserted into their respective section kiln bodies 200mm through their respective discharge devices and are located near the top of the kiln body. The flue gas recycling pipeline near the flue gas recycling nozzle 20 is equipped with 4-6 layers of 8mm aperture screens and triangular guide plates.
[0024] The specific process of using this rotary kiln unit is as follows: the material is fed into the preheating section kiln body 2 through the feeding pipe of the preheating section feeding device 1, with a unit processing capacity of 200t / h, and the temperature of the preheating section is controlled at 300-400℃. Due to the inclination and slow rotation of the preheating section kiln body, the material rolls along the circumference while moving axially from the kiln tail (high end) to the kiln head (low end). The preheated material is discharged from the preheating section discharging device 6 and fed into the high-temperature reduction roasting rotary kiln by gravity. The temperature of the high-temperature roasting section is controlled at 1200℃-1280℃. The inclination and slow rotation of the high-temperature roasting section kiln body 8 make the material move axially from the kiln tail (high end) to the kiln head (low end); pulverized coal (both fuel and reducing agent) is sprayed into the kiln from the kiln head end (low end) through a heating spray gun for combustion, and heat is transferred by radiation, convection and conduction. After the material undergoes high-temperature reduction roasting during movement, high-temperature volatile minerals such as lead and zinc in the material enter the flue gas. The flue gas is transported to the dust collecting device 13 by the dust removal fan to recover the ash. The high-temperature flue gas recovered from the dust collecting device 13 is combined with the high-temperature flue gas recovered by the hot gas recovery hood 19 after passing through the induced draft fan 14 and sent to the preheating and drying rotary kiln for recycling. The flue gas temperature entering the preheating and drying rotary kiln can reach 300°C. The produced ash can be used as a mixed concentrate of lead oxide and zinc, and metallic iron, metallic copper and copper sulfide enter the roasted sand. After the roasted sand is cooled, it is sent to the copper and iron recovery and separation process for treatment.
[0025] Its main product technical indicators are shown in Table 1.
[0026] Table 1 Statistics of technical indicators for roasting of copper smelting slag and beneficiation tailings
[0027]
[0028] As shown in Table 1, the roasted sand yield is 96%, with an iron content of 47%, 86% reduced iron, and 12.6% magnetite. The lead volatilization rate is 96.6%, and the zinc volatilization rate is 96%. This composite rotary kiln system efficiently and fully recovers valuable metals from tailings and recycles heat energy. The composite kiln design eliminates the need for refractory bricks in the preheating section, resulting in a lighter kiln body, reduced maintenance, and improved operational efficiency.
Claims
1. A composite high-temperature roasting rotary kiln unit, characterized in that: The invention comprises a preheating drying rotary kiln, a high-temperature reduction roasting rotary kiln and a heat energy recovery system. The preheating drying rotary kiln comprises a preheating section feeding device (1), a preheating section kiln body (2), a preheating section discharging device (6) and a preheating section heating spray gun (17) in sequence. The preheating section kiln body (2) is provided with a preheating section supporting wheel device (3), a preheating section rotating device (4) and a preheating section blocking supporting wheel device (5) in sequence. The high-temperature reduction roasting rotary kiln comprises a high-temperature roasting section feeding device (7), a high-temperature roasting section kiln body (8), a high-temperature roasting section discharging device (12) and a high-temperature roasting section heating spray gun (16) in sequence. The high-temperature roasting section kiln body (8) is provided with a heat insulation layer (15). The high-temperature roasting section kiln body (8) is provided with a high-temperature roasting section supporting wheel device (9), a high-temperature roasting section rotating device (10) and a high-temperature roasting section blocking supporting wheel device (11) in sequence. The heat energy recovery system comprises a dust collecting device (13), an induced draft fan (14), a flue gas recycling nozzle (20), a flue gas recovery pipeline and a flue gas recycling pipeline, wherein the flue gas recycling nozzle (20) is arranged at the inlet of the preheating section feeding device (1); the preheating section kiln body (2) and the high-temperature roasting section kiln body (8) are arranged obliquely, and the preheating section kiln body (2) is located above the high-temperature roasting section kiln body (8), and the preheating section discharging device (6) is vertically connected to the high-temperature roasting section feeding device (7); the tail of the high-temperature roasting section kiln body (8) is a flue gas box, the outlet of the flue gas box is connected to the inlet of the dust collecting device (13) via a flue gas recovery pipeline, the outlet of the dust collecting device (13) is connected to the inlet of the induced draft fan (14), and the outlet of the induced draft fan (14) is connected to the flue gas recycling nozzle (20) via a flue gas recycling pipeline.
2. A composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: It also includes a plate conveyor (18), and the heat energy recovery system also includes a hot gas recovery hood (19). The plate conveyor (18) is located below the high-temperature roasting section discharge device (12), and the hot gas recovery hood (19) is covered above the plate conveyor (18). The outlet of the hot gas recovery hood (19) is connected to the flue gas recycling pipeline via a pipeline.
3. A composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: The diameter of the preheating kiln body (2) is smaller than that of the high-temperature roasting kiln body (8).
4. A composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: The inclination angle between the preheating section kiln body (2) and the horizontal plane is greater than the inclination angle between the high-temperature roasting section kiln body (8) and the horizontal plane.
5. A composite high-temperature roasting rotary kiln unit according to claim 4, characterized in that: The inclination angle between the preheating section kiln body (2) and the horizontal plane is 4.5°, and the inclination angle between the high-temperature roasting section kiln body (8) and the horizontal plane is 3.5°.
6. The composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: The preheating section feeding device (1) and the preheating section discharging device (6) are both connected to the preheating section kiln body (2) in a sliding and sealing manner, and the high-temperature roasting section feeding device (7) and the high-temperature roasting section discharging device (12) are both connected to the high-temperature roasting section kiln body (8) in a sliding and sealing manner.
7. The composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: The preheating section kiln body (2) is made of boiler steel, the high temperature roasting section kiln body (8) is made of boiler steel, and a refractory brick layer is also laid on the inner side of the heat insulation layer (15) of the high temperature roasting section kiln body (8).
8. The composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: The preheating section heating spray gun (17) is inserted into the preheating section kiln body (2) in a horizontal direction through the preheating section discharging device (6), and is close to the top of the preheating section kiln body (2); the high-temperature roasting section heating spray gun (16) is inserted into the high-temperature roasting section kiln body (8) in a horizontal direction through the high-temperature roasting section discharging device (12), and is close to the top of the high-temperature roasting section kiln body (8).
9. The composite high-temperature roasting rotary kiln unit according to claim 1, characterized in that: A flue gas recycling pipeline close to the flue gas recycling nozzle (20) is provided with multiple layers of screens with a pore size of 6-10 mm and triangular guide plates.