A multi-cell mineral suspension smelting system

Abstract

The present application belongs to the technical field of mineral powder melting, and specifically discloses a multi-chamber mineral suspension smelting system. The present application comprises a melting furnace, a feeding device, a cyclone preheater, a main air extractor and a combustion air fan. The melting furnace comprises a central flue, a plurality of melting chambers which are distributed at equal angles around the central flue, and a molten pool which is located below the central flue and the melting chambers. The top of the melting chamber is provided with a downwardly spraying main burner, the feeding end of the main burner is connected with the material, fuel and combustion air, the high-temperature flue gas generated by the combustion of the fuel in the melting chamber melts the material, and the high-temperature flue gas after melting is extracted from the exhaust port at the top of the central flue. The cyclone preheater can recycle the high-temperature flue gas for combustion air and material preheating. The technical scheme of the present application can greatly improve the heat exchange efficiency and the uniformity of the melt by setting a plurality of melting chambers for the suspension melting of the material, and the recycling of the high-temperature flue gas is also conducive to further reducing the energy consumption.

Description

Technical Field

[0001] This invention relates to the field of mineral powder melting technology, and more specifically to a multi-chamber mineral suspension smelting system. Background Technology

[0002] In the inorganic non-metallic materials and metallurgical industries, the high-temperature melting of mineral raw materials to achieve component homogenization or phase transformation is a key step shared by many core processes. Typical scenarios include: melt-drawing production of basalt fiber and mineral wool fiber, melt-reduction ironmaking of iron ore powder, smelting of copper concentrate, and calcination and melting of bauxite. Although these processes belong to different downstream industries, they face common underlying technological challenges in the thermal treatment stage.

[0003] Take basalt fiber as an example. Currently, basalt fiber is mainly produced using flame furnaces and combined fire-electric furnaces. Although the technology is mature and the product quality is stable, its industrialization faces significant bottlenecks. This is because basalt raw materials typically contain more than 10% Fe. 3+ Iron ions cause the molten basalt to be dark brown and have poor light transmittance, thus hindering heat transfer through radiation. Secondly, the very high viscosity of basalt melt results in minimal internal convection, leading to poor convective heat transfer. Furthermore, the melt itself has poor thermal conductivity, with a low coefficient of only about 2 W / (m·K), resulting in extremely weak conductive heat transfer. These characteristics of basalt raw materials inevitably lead to the following technical drawbacks when using flame furnaces or combined thermal-electric furnaces for production:

[0004] 1. High energy consumption in production

[0005] The heat transfer bottleneck of existing flame-fired tank kilns stems from inherent defects in their energy transfer path: after the high-temperature flame transfers heat to the surface of the basalt melt through radiation and convection, the heating of the deeper melt relies entirely on heat conduction, resulting in an effective heat exchange depth of less than 200 mm in the molten pool. Of the heat generated by fuel combustion, approximately 55-65% is directly emitted through the chimney as high-temperature flue gas at 400-600°C. Even with the addition of shell-and-tube flue gas heat exchangers for waste heat recovery, the actual thermal energy utilization rate is still less than 35%. This inherent deficiency in energy transfer efficiency results in a comprehensive energy consumption of 3-4 GJ / t per unit product for flame-fired tank kilns, which is 40-50% higher than that of similar glass fiber products. Fuel costs account for more than 40% of the total production cost, becoming a key factor restricting production cost control.

[0006] 2. Low production efficiency

[0007] In existing pool furnace production processes, the heat transfer efficiency from the flame to the basalt melt is very low. The propagation of heat into the molten pool requires a very slow heat conduction process, resulting in very low output per pool furnace, with the annual capacity of a single unit generally below 5,000 tons. Simultaneously, the direct impact of the gas jet on the material surface at a certain speed creates an upward rebound velocity. This velocity can easily induce some gas to escape from the top of the jet hood, further impacting production efficiency.

[0008] 3. Poor melt quality

[0009] Because the heat conduction path in the furnace pool is long (depth 150~180mm), there is a temperature gradient of 100~200℃ from top to bottom in the melt, which causes fluctuations in the temperature and viscosity of the discharged melt, directly affecting the online fiber breakage rate of basalt fiber drawing (current level about 5~15 times per machine per day) and the uniformity of the strength of the finished fiber (coefficient of variation CV is usually >8%).

[0010] 4. Long material replacement cycle

[0011] The furnace contains a large amount of melt (several tons to tens of tons). When changing the raw material formula or adjusting the process, it takes several hours to several days to achieve complete replacement of the melt composition, resulting in poor production flexibility.

[0012] The aforementioned defects result in basalt fiber production being significantly inferior to the mature, large-scale production system of traditional glass fiber, particularly in terms of cost control and capacity efficiency. This severely weakens its competitiveness in the composite materials market and has become a key technological barrier restricting industrial breakthroughs. Summary of the Invention

[0013] The main objective of this invention is to provide a multi-chamber mineral suspension smelting system to solve the problems of high energy consumption, low production efficiency, and insufficient melt uniformity in existing mineral melting production technologies.

[0014] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0015] A multi-chamber mineral suspension smelting system includes a melting furnace, a feeding device, a cyclone preheater, a main exhaust fan, and a combustion fan. The melting furnace includes a central flue, multiple melting chambers spaced at equal angles around the central flue, and a molten pool located below the central flue and the melting chambers. A molten material outlet is located at the bottom of the molten pool. An exhaust port is located at the top of the central flue. Each melting chamber has a main burner with its injection axis pointing vertically downwards at its top. The exhaust port connects to the air inlet of the cyclone preheater, and the air outlet of the cyclone preheater connects to the main exhaust fan. The feed inlet of the cyclone preheater connects to the discharge outlet of the feeding device. The discharge outlet of the cyclone preheater, the discharge outlet of the combustion fan, and the fuel supply pipe are all connected to the feed end of the main burner.

[0016] This invention employs a multi-chamber suspension melting scheme. A central flue is positioned above the molten pool, surrounded by multiple melting chambers (typically 3-12) spaced at equal angles. Fuel (usually natural gas), combustion air, and powder are injected into the melting chambers from the main burner at the top. The high-temperature flue gas generated by combustion melts the powder. A main exhaust fan draws the high-temperature flue gas from each melting chamber to the top of the central flue for discharge. During this process, the material undergoes a dynamic process of suspension-melting-growth-settling, ultimately separating from the high-temperature flue gas and falling into the bottom molten pool. The multi-chamber design allows for the simultaneous melting of large quantities of material, avoiding the problem of incomplete melting that often occurs when melting large quantities in a single furnace, thus improving production efficiency and melt uniformity. Furthermore, compared to the traditional tank furnace method, suspension melting allows for a larger specific surface area of ​​the powder, enabling more thorough contact with the high-temperature flue gas, thereby improving production efficiency and reducing energy consumption. Moreover, the suspended powder particles are heated uniformly, preventing temperature gradients and component stratification within the molten pool, resulting in excellent melt uniformity.

[0017] In this invention, fuel, powder, and combustion air are all introduced into the main burner. These three components can be premixed before injection. Specifically, a dedicated mixing chamber can be provided, where the fuel, powder, and combustion air are uniformly mixed before injection. Alternatively, separate flow channels can be provided within the main burner, each connected to a corresponding conveying pipe. After being injected through the main burner, the three components are mixed within the furnace chamber of the melting furnace. An igniter is installed at the outlet of the main burner to ignite the mixture ejected from the burner. Each main burner's fuel delivery pipe, powder delivery pipe, and combustion air delivery pipe are equipped with corresponding valves to control their respective conveying rates, thereby controlling the amount of high-temperature flue gas and the melting status of the powder in each melting chamber.

[0018] In this invention, the raw materials need to be crushed before preheating, typically to a particle size of less than 1 mm, thereby further improving the preheating efficiency and melting efficiency of the powder. The crushed powder is placed in a feeding device to supply the cyclone preheater. The feeding device is usually a hopper. The cyclone preheater is existing technology and will not be described in detail here. In this invention, the main exhaust fan draws the gas from the molten furnace through the flue gas outlet and sends it into the cyclone preheater to preheat the material. The flue gas after preheating the material can also be used to preheat the combustion air, thereby achieving further waste heat utilization and helping to reduce energy consumption. Furthermore, both the central flue and the melting chamber are cylindrical.

[0019] Preferably, the bottom surface of the molten pool includes a central bottom surface located in the middle, and an annular bottom surface surrounding the central bottom surface. The horizontal projection of the molten chamber lies within the central bottom surface. The central bottom surface is higher than its surrounding area in the middle, and gradually decreases in height from the middle to the surrounding area. The annular bottom surface is horizontally positioned. The molten material outlets are located on the annular bottom surface, and a plurality of molten material outlets are evenly arranged circumferentially along the annular bottom surface.

[0020] This design allows the molten material to first drip onto the central bottom surface and then slide down to the molten material outlet located on the annular bottom surface. This facilitates the dispersion of the molten droplets to each outlet, enabling the melt to flow out for downstream processing. Furthermore, the central bottom surface is conical.

[0021] Preferably, an annular molten pool dike is provided on the central bottom surface. The horizontal projections of the central flue and the molten chamber are both located inside the molten pool dike. Multiple molten material channels are provided at the bottom of the molten pool dike.

[0022] Specifically, the molten material channels are formed through a through-wall gap at the bottom of the molten pool cofferdam, allowing the melt to flow from the inside to the outside of the cofferdam. Furthermore, the number of molten material channels and molten material outlets are the same, and they correspond one-to-one.

[0023] Specifically, the molten droplets first fall into the inner side of the dam, then enter the outer side of the dam through the molten material channel at the bottom, and finally exit through the molten material outlet. This design is because some incompletely molten fine powder may exist on the surface of the melt. If the melt is taken from the surface, this fine powder will directly enter the downstream processing stage (such as fiber drawing), affecting the quality of the final product (such as fiber breakage). However, by taking the melt from the bottom, the incompletely molten powder will further melt as it descends in the molten pool, resulting in better quality uniformity with the surrounding melt and improving the quality of downstream processing.

[0024] Preferably, a plurality of first baffles and a plurality of second baffles are provided on the bottom surface of the molten pool. One end of the first baffle originates from the lower edge of the central flue, and the other end extends radially to the inner wall of the molten pool. Adjacent first baffles form a flow channel corresponding to one of the molten chambers. One end of the second baffle originates from the outer wall of the molten pool weir, and the other end extends radially to the inner wall of the molten pool. Adjacent first and second baffles, and between adjacent second baffles, form a flow channel corresponding to one molten material channel and one molten material outlet.

[0025] Specifically, the internal space of the molten pool is divided into multiple melt flow spaces (i.e., primary flow channels) by a first baffle. Each melt flow space corresponds to a melting chamber above it. Molten droplets in each melting chamber can drip into the corresponding melt flow space below. The melt dripping into the melt flow space slides down the central bottom surface to the outer annular bottom surface. On the annular bottom surface, adjacent molten material outlets are separated by baffles. That is, each molten material outlet corresponds to a secondary flow channel separated by two adjacent second baffles or adjacent first and second baffles. The sliding melt is diverted to different secondary flow channels through the molten material channel at the bottom of the cofferdam and finally flows out from the corresponding molten material outlet. This arrangement allows the melting operation of each melting chamber to be relatively independent and not interfere with each other. Each melting chamber can operate individually or simultaneously, and the production scale can be flexibly adjusted.

[0026] Preferably, the bottom of the molten pool is provided with a plurality of funnel-shaped discharge channels, and each discharge channel is evenly arranged in a ring around the outside of the molten pool dike. The larger end of the discharge channel is connected to the molten pool, and the smaller end of the discharge channel forms the outlet of the molten material.

[0027] The funnel-shaped discharge channels facilitate the accumulation and outflow of molten material, preventing molten material from remaining in the molten pool. The evenly distributed, ring-shaped discharge channels on the outside of the molten pool's containment dike ensure uniform discharge of molten material from each outlet, which is beneficial for downstream processing.

[0028] Preferably, the ratio of the height of the molten chamber to the height of the central flue is 0.6 to 0.8:1. The ratio of the diameter of the central flue to the diameter of the molten pool is 0.2 to 0.35:1.

[0029] The above settings are designed to create a furnace environment for efficient melting and gas-solid separation of materials, allowing the materials sufficient reaction time and space for gas-solid separation, thereby ensuring that each powder particle can be fully melted, which is beneficial to the uniformity of the melt.

[0030] Preferably, the melting chamber includes an inner melting chamber near the central flue and an outer melting chamber away from the central flue, with the inner and outer melting chambers alternating. The ratio of the horizontal distance from the central axis of the outer melting chamber to the central axis of the central flue is 1.2 to 2:1.

[0031] Specifically, the inner melting chamber is closer to the central flue, resulting in a shorter flue gas path, making it suitable for processing finer-grained powder particles. The outer melting chamber is farther from the central flue, resulting in a longer flow path for the high-temperature flue gas and thus a longer contact time between the flue gas and the powder, making it suitable for processing coarser-grained powder particles. The combination of inner and outer melting chambers allows for the simultaneous processing of materials of different particle sizes, ensuring a more consistent melting consistency between coarse and fine particles. For example, basalt powder can be sieved into a fine-grained grade (d...). 50 <200um) and coarse-grained (d 50 (200~1000um), fine particles are supplied to the inner melting tower, and coarse particles are supplied to the outer melting tower, thus realizing the melting of materials of different particle sizes in the same melting furnace.

[0032] Preferably, an annular collecting groove is provided between the central bottom surface and the annular bottom surface, and the two sides of the groove opening are respectively connected to the central bottom surface and the annular bottom surface. The bottom of the collecting groove has multiple discharge ports, which are evenly distributed circumferentially along the bottom of the groove.

[0033] This embodiment can be used to simultaneously recover iron during the smelting of iron-containing minerals. Taking basalt as an example, which contains approximately 10%~15% Fe2O3 / FeO, during the melting process, iron oxides are partially reduced to metallic iron (reduction rate 20%~40%) at high temperatures above 1500℃ and under a localized CO reducing atmosphere. The density of the molten iron is approximately 7.0 g / cm³. 3 It is much larger than that of basalt melt (~2.6 g / cm³). 3 Because the collecting tank is located at the lowest point of the central bottom surface, molten iron can slide down the central bottom surface and sink into the collecting tank under the influence of gravity, and then be periodically discharged through the discharge port to be cast into iron ingots, thus achieving the separation and recovery of iron. This process requires no additional reducing agent and has low operating costs. Furthermore, the depth of the collecting tank is usually 50~150mm. It should be noted that a collecting tank is not required when smelting iron ore.

[0034] Preferably, the collection tank is provided with an annular overflow baffle along the outer edge of the tank opening.

[0035] The annular overflow baffle divides the molten pool into an inner molten settling zone and an outer clarifying discharge zone. During the iron collection process, the molten droplets on the inner side are further homogenized and degassed at high temperatures. When the liquid level exceeds the top of the overflow baffle, the upper layer of pure melt overflows to the outer side and is stably discharged through the corresponding molten material outlet. This structure effectively prevents impurities from entering subsequent processes, achieving self-purification of the melt and stable discharge.

[0036] Preferably, a reducing agent injection port is provided at the lower part of the central flue, and the reducing agent injection port is evenly arranged along the circumference of the central flue.

[0037] Alternatively, a reducing agent injection port may be provided at the upper part of the molten pool, and the reducing agent injection ports may be evenly arranged along the circumference of the molten pool. The horizontal projection of the reducing agent injection port is located within the central bottom surface.

[0038] Alternatively, a pair of graphite electrodes may be provided on the central bottom surface.

[0039] In this embodiment, a reducing agent is further injected into the furnace to enhance the iron separation effect, or the melt is electrolyzed through a graphite electrode to further promote iron reduction.

[0040] Specifically, by setting reducing agent injection inlets (usually 1-4) at the bottom of the central flue or the top of the molten pool, and injecting reducing agents such as pulverized coal or natural gas, Fe2O3 / FeO can be reduced to metallic iron, increasing the reduction rate to 80%-95% and significantly improving the iron recovery rate. It is important to note that the amount of reducing agent used must be controlled to avoid over-reduction of SiO2 and Al2O3.

[0041] Specifically, graphite electrode pairs (DC 3~6V, 0.5~2A / cm) 2 ), through electrolysis to remove Fe 2+ / Fe 3+ The iron is reduced to metallic iron at the cathode, with a reduction rate of >95% and high product purity.

[0042] The above scheme has the following advantages when combined with fiber production: (1) After the molten iron is discharged, the iron content of the melt is reduced to 2%~5%, and the light transmittance is improved. (2) Based on an annual production of 10,000 tons of fiber, about 1,000 tons of iron can be recovered per year, creating additional income.

[0043] Preferably, the system further includes a secondary heating device. The secondary heating device is disposed above the annular bottom surface and is evenly distributed along the circumference of the molten pool. The secondary heating device is at least one of an auxiliary burner, a heating resistor, and a medium-frequency induction coil.

[0044] The secondary heating device provides surface heating for the melt, maintaining a uniform surface temperature (gradient <30℃), promoting bubble rise and discharge, and reducing wire breakage rate. Specifically, the secondary heating device is typically positioned 300-800 mm above the free surface of the melt, and its heat replenishment accounts for 5%-15% of the total heat. The auxiliary burner can be a small natural gas burner. The heating resistor can be a MoSi2 or SiC heating element with a power density of 10-50 kW / m³. 2 The intermediate frequency induction coil is heated by electromagnetic induction. These three components can also be combined for synergistic effects.

[0045] Preferably, a cyclone separator is installed at the top of the central flue. The outlet of the cyclone separator is connected to the exhaust port.

[0046] Specifically, cyclone separators are used to separate the gas and liquid in the flue gas that is about to leave the exhaust port. By using centrifugal force, the tiny liquid droplets carried in the gas flow are thrown off and flowed back to the molten pool, thereby reducing material loss.

[0047] Preferably, the system further includes a flue gas heat exchanger. The flue gas heat exchanger is provided with a flue gas passage and an air passage for counter-current heat exchange via a partition wall. The air inlet of the flue gas passage is connected to the air outlet of the cyclone preheater, and the air outlet of the flue gas passage is connected to the air inlet of the main exhaust fan. The air inlet of the air passage is connected to the air outlet of the combustion fan, and the air outlet of the air passage is connected to the feed end of the main burner.

[0048] This embodiment utilizes a flue gas heat exchanger to recycle the waste heat of the flue gas after it has been preheated for materials in the cyclone preheater. Specifically, through heat transfer via the partition wall, the high-temperature flue gas preheats the combustion air, thereby enhancing combustion, further saving energy, and reducing energy consumption.

[0049] Preferably, a preheated air inlet is provided on the side wall of the central flue. The preheated air inlet is connected to the air outlet of the air channel.

[0050] The preheating air inlet is usually located in the lower middle part of the side wall of the central flue. By injecting preheating air through the preheating air inlet, the CO (0.5%~3%) and H2 in the flue gas can be burned off, thereby forming a secondary combustion zone in the central flue, improving fuel utilization by 2%~5%, and further promoting powder melting.

[0051] Preferably, the system further includes a downstream processing device. The downstream processing device is located below the molten material outlet. The downstream processing device is one of a forming device, a reduction furnace, a converter, an anode furnace, or an electrolytic cell.

[0052] This invention can be used in mineral smelting for both fiber and non-fiber production. When the downstream process is basalt fiber production, the downstream processing unit is a drawing machine. When the downstream process is iron ore reduction ironmaking, the downstream processing unit is a reduction furnace. When the downstream process is copper smelting, the downstream processing unit is a converter or anode furnace. When the downstream process is bauxite smelting, the downstream processing unit is an electrolytic cell. Of course, the downstream processing unit can also be a casting / forming device used in other mineral smelting processes.

[0053] Preferably, the downstream processing device is a wire drawing device. A stencil is provided at the outlet of the molten material. The wire drawing device is located below the stencil.

[0054] The fiber drawing device is one embodiment of the downstream processing unit used to produce basalt fibers. It is prior art and will not be described in detail here. The spinneret is a well-known spinneret for drawing basalt (or glass) fibers (with an aperture typically of 0.6~1.0mm ± 0.02mm), usually made of platinum-rhodium alloy. It has several discharge holes at the bottom through which the high-temperature molten metal flows into the fiber drawing device for stretching and forming. Those skilled in the art can select spinnerets with different apertures and numbers of holes according to the diameter of the target fiber and the required production volume.

[0055] Taking basalt fiber production as an example, the specific production process of the system is as follows: Powdered basalt raw material (particle size generally required to be <1mm) is fed into the inlet pipe section of the cyclone preheater from the top feeding device (usually a hopper), where it mixes with the high-temperature flue gas coming from the exhaust port, forming a gas-solid mixture that enters the cyclone preheater. After heat exchange in the cyclone preheater, the gas and solid separate, and the cooled flue gas is discharged from the top outlet of the cyclone preheater, while the preheated basalt powder is discharged from the bottom outlet of the cyclone preheater. The preheated basalt powder, along with preheated combustion air and fuel, is injected into the melting chamber from the top main burner. The powder is scattered, and the fuel and air burn in the chamber to form high-temperature flue gas. As the high-temperature flue gas carries the powder downwards, intense heat exchange occurs between the gas and solid. Due to the large specific surface area of ​​the powder, the contact area between a unit mass of material and the high-temperature flue gas is large. Simultaneously, there is strong turbulence between the material and the airflow, resulting in a high heat transfer coefficient. Therefore, the powder is rapidly heated to above its melting temperature (approximately 1500℃) as it moves with the high-temperature flue gas, forming molten basalt droplets. This process typically completes within seconds. The material undergoes a dynamic process of suspension-melting-growth-settling. When the droplets grow to a certain size, the pneumatic drag force cannot overcome gravity to transport them. Under gravity, the droplets fall into the bottom molten pool, while the flue gas is ultimately drawn away from the central flue by the main exhaust fan, achieving separation of the high-temperature flue gas and the molten droplets. The molten droplets accumulate in the bottom molten pool and flow from the molten material channel at the bottom of the molten pool dike into the funnel-shaped discharge channel, eventually flowing out from the bottom of the perforated plate to form the original filament. During this process, the reduced molten iron slides down the central bottom surface under gravity and settles into the collection tank, where it is periodically discharged. The raw filaments are drawn into basalt fibers by the lower drawing machine, forming continuously produced basalt fibers. The high-temperature flue gas discharged from the top exhaust port of the central flue undergoes two stages of waste heat utilization—a cyclone preheater and a flue gas heat exchanger—before finally being discharged from the system by the main exhaust fan. The preheated combustion air can also be introduced into the central flue to form a secondary combustion zone, further ensuring the complete melting of the material.

[0056] Of course, when processing other minerals (such as iron ore), the operating parameters and downstream processing equipment need to be adjusted accordingly based on the material's density and melting point.

[0057] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0058] 1. In this invention, the powder material and high-temperature flue gas directly contact each other for heat exchange in a turbulent suspended state, significantly improving the heat transfer coefficient, which is beneficial for improving energy utilization efficiency and reducing energy consumption. Simultaneously, the powdered material has a large specific surface area (in d...). 50 Based on a thickness of 150μm, approximately 14m 2The melting process can be completed within seconds, significantly increasing the annual capacity of a single unit and greatly improving production efficiency. Furthermore, in the suspended state, each powder particle is heated and melted almost simultaneously, eliminating the temperature gradient and component stratification of the molten material found in tank furnaces, resulting in excellent melt uniformity. In addition, the amount of material remaining in the melting furnace is much less than in tank furnaces, reducing the time required to change raw material formulations or adjust processes, thus significantly improving production flexibility.

[0059] 2. This invention employs a multi-chamber suspension melting scheme, with each melting chamber arranged around a central flue. Material melts within the melting chambers, and the main exhaust fan draws the high-temperature flue gas from each melting chamber to the central flue, from which it is discharged. This arrangement allows for simultaneous melting of large quantities of material, improving production efficiency. Simultaneously, the bottom molten pool is divided into melt channels corresponding to each melting chamber and the molten material outlet by first and second baffles, enabling each melting chamber to operate independently or simultaneously without interference, allowing for flexible adjustment of production scale.

[0060] 3. This invention divides multiple melting chambers into inner melting chambers and outer melting chambers. The inner melting chamber is closer to the central flue and has a shorter flue gas path, which is used to process finer-sized powder particles. The outer melting chamber is farther from the central flue and has a longer flow path for the high-temperature flue gas, thus resulting in a longer contact time between the flue gas and the powder, which is used to process coarser-sized powder particles. Combined with the secondary combustion zone set in the central flue, particles of different sizes can be fully melted, ensuring the uniformity of the melt.

[0061] 4. In this invention, a collection tank for separating and recovering iron is provided between the central bottom surface and the annular bottom surface of the molten pool. During the melting process of the powder, iron oxides can be partially reduced to metallic iron under high temperatures above 1500℃ and a local CO reducing atmosphere, thus naturally settling into the collection tank and being discharged from the discharge port at the bottom of the collection tank. This achieves iron collection while improving the quality of the melt. Furthermore, this invention also includes a reducing agent injection port and / or a graphite electrode pair to further promote the separation and recovery of iron through reduction and / or electrolysis.

[0062] 5. In this invention, the high-temperature flue gas discharged from the exhaust port can enter the cyclone preheater to preheat the material. The high-temperature flue gas after preheating the material can then enter the flue gas heat exchanger to preheat the combustion air, forming hot combustion air. The hot combustion air can be introduced into the burner at the top of the melting chamber to promote the combustion of fuel in the melting chamber, and can also be introduced into the preheated air inlet to form a secondary combustion zone in the central flue, so that CO and H2 in the flue gas are burned off completely. This ensures that the powder that is not fully melted in the melting chamber can be fully melted, further improving the energy utilization efficiency of the system and helping to reduce energy consumption. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of an embodiment of the multi-chamber mineral suspension smelting system of the present invention.

[0064] Figure 2 This is a schematic diagram of another embodiment of the multi-chamber mineral suspension smelting system of the present invention.

[0065] Figure 3 This is a cross-sectional view of section AA, representing an embodiment of the molten chamber distribution in the multi-chamber mineral suspension smelting system of the present invention.

[0066] Figure 4 This is a cross-sectional view of section AA, representing another embodiment of the molten chamber distribution in the multi-chamber mineral suspension smelting system of the present invention.

[0067] Figure 5 for Figure 3 A schematic cross-sectional view of the BB section of the embodiment shown.

[0068] Figure label:

[0069] 1: Melting chamber; 101: Inner melting chamber; 102: Outer melting chamber; 2: Central flue; 3: Molten pool; 4: Central bottom surface; 5: Main burner; 6: Discharge channel; 7: Downstream processing device; 8: Molten pool dike; 9: Molten material channel; 10: First baffle; 11: Second baffle; 12: Feeding device; 13: Cyclone preheater; 14: Flue gas heat exchanger; 15: Main exhaust fan; 16: Combustion fan; 17: Secondary heating device; 18: Collection tank; 19: Overflow baffle. Detailed Implementation

[0070] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0071] Please refer to Figures 1 to 5 A multi-chamber mineral suspension smelting system includes a melting furnace, a feeding device 12, a cyclone preheater 13, a main exhaust fan 15, and a combustion fan 16. The melting furnace includes a central flue 2, multiple melting chambers 1 spaced at equal angles around the central flue 2, and a molten pool 3 located below the central flue 2 and the melting chambers 1. A molten material outlet is located at the bottom of the molten pool 3. A flue gas outlet is located at the top of the central flue 2. Each melting chamber 1 has a main burner 5 with its injection axis pointing vertically downwards at its top. The flue gas outlet connects to the air inlet of the cyclone preheater 13, and the air outlet of the cyclone preheater 13 connects to the main exhaust fan 15. The feed inlet of the cyclone preheater 13 connects to the discharge outlet of the feeding device 12. The discharge outlet of the cyclone preheater 13, the air outlet of the combustion fan 16, and the fuel supply pipe are all connected to the feed end of the main burner 5.

[0072] Preferably, the bottom surface of the molten pool 3 includes a central bottom surface 4 located in the middle, and an annular bottom surface surrounding the central bottom surface 4. The horizontal projection of the molten chamber 1 lies within the central bottom surface 4. The central bottom surface 4 is higher than its surrounding area in the middle, and gradually decreases in height from the middle to the surrounding area. The annular bottom surface is horizontally positioned. The molten material outlets are located on the annular bottom surface, and a plurality of molten material outlets are evenly arranged circumferentially along the annular bottom surface.

[0073] Preferably, an annular molten pool weir 8 is provided on the central bottom surface 4. The horizontal projections of the central flue 2 and the molten chamber 1 are both located inside the molten pool weir 8. Multiple molten material channels 9 are provided at the bottom of the molten pool weir 8.

[0074] Preferably, a plurality of first baffles 10 and a plurality of second baffles 11 are provided on the bottom surface of the molten pool 3. One end of the first baffle 10 starts from the lower edge of the central flue 2, and the other end of the first baffle 10 extends radially to the inner wall of the molten pool 3. The flow channels between two adjacent first baffles 10 are used to form a flow channel corresponding to one of the molten chambers 1. One end of the second baffle 11 starts from the outer wall of the molten pool weir 8, and the other end of the second baffle 11 extends radially to the inner wall of the molten pool 3. The flow channels between adjacent first baffles 10 and second baffles 11, and between two adjacent second baffles 11, are used to form a flow channel corresponding to one of the molten material channels 9 and one of the molten material outlets.

[0075] Preferably, the bottom of the molten pool 3 is provided with a plurality of funnel-shaped discharge channels 6, and each discharge channel 6 is evenly arranged in a ring around the outside of the molten pool dike 8. The large end of the discharge channel 6 is connected to the molten pool 3, and the small end of the discharge channel 6 forms the outlet of the molten material.

[0076] Preferably, the ratio of the height of the molten chamber 1 to the height of the central flue 2 is 0.6~0.8:1. The ratio of the diameter of the central flue 2 to the diameter of the molten pool 3 is 0.2~0.35:1.

[0077] Preferably, the melting chamber 1 includes an inner melting chamber 101 near the central flue 2 and an outer melting chamber 102 away from the central flue 2, with the inner melting chamber 101 and the outer melting chamber 102 alternately arranged. The ratio of the horizontal distance from the central axis of the outer melting chamber 102 and the inner melting chamber 101 to the central axis of the central flue 2 is 1.2 to 2:1.

[0078] Preferably, an annular collecting groove 18 is provided between the central bottom surface 4 and the annular bottom surface, and the two sides of the groove opening of the collecting groove 18 are respectively connected to the central bottom surface 4 and the annular bottom surface. The bottom of the collecting groove 18 has multiple discharge ports, and each discharge port is evenly distributed along the annular bottom of the groove.

[0079] Preferably, the collection trough 18 is provided with an annular overflow baffle 19 along the outer edge of the trough opening.

[0080] Preferably, a reducing agent injection port is provided at the lower part of the central flue 2, and the reducing agent injection port is evenly arranged along the circumference of the central flue 2.

[0081] Alternatively, a reducing agent injection port may be provided at the upper part of the molten pool 3, and the reducing agent injection ports may be evenly arranged along the circumference of the molten pool 3. The horizontal projection of the reducing agent injection port is located within the central bottom surface 4.

[0082] Alternatively, a pair of graphite electrodes may be provided on the central bottom surface 4.

[0083] Preferably, the system further includes a secondary heating device. The secondary heating device is disposed above the annular bottom surface and is evenly distributed along the circumference of the molten pool 3. The secondary heating device is at least one of an auxiliary burner, a heating resistor, and a medium-frequency induction coil.

[0084] Preferably, a cyclone separator is provided at the top of the central flue 2. The outlet of the cyclone separator is connected to the exhaust port.

[0085] Preferably, the system further includes a flue gas heat exchanger 14. The flue gas heat exchanger 14 is provided with a flue gas passage and an air passage for countercurrent heat exchange through a partition wall. The air inlet of the flue gas passage is connected to the air outlet of the cyclone preheater 13, and the air outlet of the flue gas passage is connected to the air inlet of the main exhaust fan 15. The air inlet of the air passage is connected to the air outlet of the combustion fan 16, and the air outlet of the air passage is connected to the feed end of the main burner 5.

[0086] Preferably, a preheated air inlet is provided on the side wall of the central flue 2. The preheated air inlet is connected to the air outlet of the air channel.

[0087] Preferably, the system further includes a downstream processing device 7. The downstream processing device 7 is located below the outlet of the molten material. The downstream processing device 7 is one of a forming device, a reduction furnace, a converter, an anode furnace, and an electrolytic cell.

[0088] Preferably, the downstream processing device 7 is a wire drawing device. A stencil is provided at the outlet of the molten material. The wire drawing device is located below the stencil.

[0089] Example 1

[0090] A multi-chamber mineral suspension smelting system includes a melting furnace, a feeding device 12, a cyclone preheater 13, a main exhaust fan 15, and a combustion fan 16. The melting furnace includes a central flue 2, six melting chambers 1 evenly spaced around the central flue 2, and a molten pool 3 located below the central flue 2 and the melting chambers 1. A molten material outlet is located at the bottom of the molten pool 3. A flue gas outlet is located at the top of the central flue 2. Each melting chamber 1 has a main burner 5 with its injection axis pointing vertically downwards at its top. The flue gas outlet connects to the air inlet of the cyclone preheater 13, and the air outlet of the cyclone preheater 13 connects to the main exhaust fan 15. The feed inlet of the cyclone preheater 13 connects to the discharge outlet of the feeding device 12. The discharge outlet of the cyclone preheater 13, the air outlet of the combustion fan 16, and the fuel supply pipe are all connected to the feed end of the main burner 5.

[0091] Example 2

[0092] The embodiment 1 is repeated, except that the bottom surface of the molten pool 3 includes a central bottom surface 4 located in the middle, and an annular bottom surface surrounding the central bottom surface 4. The horizontal projection of the molten chamber 1 lies within the central bottom surface 4. The center of the central bottom surface 4 is higher than its surroundings, and gradually decreases in height from the center to the surroundings. The annular bottom surface is horizontally positioned. The molten material outlets are located on the annular bottom surface, and 18 molten material outlets are evenly arranged circumferentially along the annular bottom surface.

[0093] Specifically, the central bottom surface 4 is a conical bottom surface.

[0094] Example 3

[0095] The embodiment 2 is repeated, except that an annular molten pool dike 8 is provided on the central bottom surface 4. The horizontal projections of the central flue 2 and the molten chamber 1 are both located inside the molten pool dike 8. The bottom of the molten pool dike 8 has 18 molten material channels 9.

[0096] Example 4

[0097] The embodiment 3 is repeated, except that six first baffles 10 and twelve second baffles 11 are provided on the bottom surface of the molten pool 3. One end of the first baffle 10 starts from the lower edge of the central flue 2, and the other end of the first baffle 10 extends radially to the inner wall of the molten pool 3. The space between two adjacent first baffles 10 forms a flow channel corresponding to one of the molten chambers 1. One end of the second baffle 11 starts from the outer wall of the molten pool weir 8, and the other end of the second baffle 11 extends radially to the inner wall of the molten pool 3. The space between adjacent first baffles 10 and second baffles 11, and between two adjacent second baffles 11, forms a flow channel corresponding to one molten material channel 9 and one molten material outlet.

[0098] Example 5

[0099] The embodiment 4 is repeated, except that the bottom of the molten pool 3 is provided with 18 funnel-shaped discharge channels 6, which are evenly arranged in a ring around the outside of the molten pool dike 8. The larger end of the discharge channel 6 is connected to the molten pool 3, and the smaller end of the discharge channel 6 forms the outlet of the molten material.

[0100] Example 6

[0101] Example 5 is repeated, except that the ratio of the height of the molten chamber 1 to the height of the central flue 2 is 0.72:1. The ratio of the diameter of the central flue 2 to the diameter of the molten pool 3 is 0.242:1.

[0102] The molten chamber 1 has a height of 3.6m, the central flue 2 has a height of 5m and a diameter of 1.5m, the molten pool 3 has a diameter of 6.2m, and the molten chamber has a diameter of 0.6m.

[0103] Example 7

[0104] Example 6 is repeated, except that the melting chamber 1 includes an inner melting chamber 101 closer to the central flue 2 and an outer melting chamber 102 farther from the central flue 2, with the inner melting chamber 101 and the outer melting chamber 102 alternately arranged. The ratio of the horizontal distance from the central axis of the outer melting chamber 102 and the inner melting chamber 101 to the central axis of the central flue 2 is 1.6:1.

[0105] The horizontal distance between the central axis of the inner molten chamber and the central axis of the central flue is 1.5m, and the horizontal distance between the central axis of the outer molten chamber and the central axis of the central flue is 2.4m.

[0106] Example 8

[0107] The embodiment 7 is repeated, except that an annular collection trough 18 is provided between the central bottom surface 4 and the annular bottom surface, and the two sides of the opening of the collection trough 18 are respectively connected to the central bottom surface 4 and the annular bottom surface. The bottom of the collection trough 18 has 12 discharge ports, and the discharge ports are evenly distributed along the annular bottom of the trough.

[0108] The depth of the collection tank is 120mm.

[0109] Example 9

[0110] The embodiment 8 is repeated, except that the collection tank 18 is provided with an annular overflow baffle 19 along the outer edge of the tank opening.

[0111] Example 10

[0112] Example 9 is repeated, except that a reducing agent injection port is provided at the lower part of the central flue 2, and the reducing agent injection port is evenly arranged along the circumference of the central flue 2.

[0113] Example 11

[0114] Repeat Example 9, except that a reducing agent injection port is provided at the upper part of the molten pool 3, the reducing agent injection port is evenly arranged along the circumference of the molten pool 3, and the horizontal projection of the reducing agent injection port is located in the central bottom surface 4.

[0115] Example 12

[0116] Example 9 is repeated, except that a pair of graphite electrodes is provided on the central bottom surface 4.

[0117] Example 13

[0118] The system is repeated in Embodiment 10, except that it further includes a secondary heating device. The secondary heating device is located above the annular bottom surface and is evenly distributed along the circumference of the molten pool 3.

[0119] Example 14

[0120] Repeat Example 13, except that the secondary heating device is an auxiliary burner.

[0121] Example 15

[0122] Repeat Example 13, except that the secondary heating device is a heating resistor.

[0123] Example 16

[0124] Repeat Example 13, except that the secondary heating device is a medium-frequency induction coil.

[0125] Example 17

[0126] The embodiment 14 is repeated, except that a cyclone separator is provided at the top of the central flue 2. The outlet of the cyclone separator is connected to the exhaust port.

[0127] Example 18

[0128] The system is a repeat of Embodiment 17, except that it further includes a flue gas heat exchanger 14. The flue gas heat exchanger 14 has a flue gas passage and an air passage for counter-current heat exchange via a partition wall. The inlet of the flue gas passage is connected to the outlet of the cyclone preheater 13, and the outlet of the flue gas passage is connected to the inlet of the main exhaust fan 15. The inlet of the air passage is connected to the outlet of the combustion fan 16, and the outlet of the air passage is connected to the feed end of the main burner 5.

[0129] Example 19

[0130] The embodiment 18 is repeated, except that a preheated air inlet is provided on the side wall of the central flue 2. The preheated air inlet is connected to the air outlet of the air channel.

[0131] Example 20

[0132] The system is a repeat of Embodiment 19, except that it further includes a downstream processing device 7, which is a wire drawing device. A perforated plate is provided at the outlet of the molten material. The wire drawing device is located below the perforated plate.

Claims

1. A multi-chamber mineral suspension smelting system, characterized in that: The system includes a melting furnace, a feeding device (12), a cyclone preheater (13), a main exhaust fan (15), and a combustion fan (16); the melting furnace includes a central flue (2), multiple melting chambers (1) spaced at equal angles around the central flue (2), and a molten pool (3) located below the central flue (2) and the melting chambers (1); the bottom of the molten pool (3) has a molten material outlet; the top of the central flue (2) has a flue gas outlet; each of the melting chambers... (1) The top of each burner is provided with a main burner (5) with the injection axis pointing vertically downward; the exhaust port is connected to the air inlet of the cyclone preheater (13), and the air outlet of the cyclone preheater (13) is connected to the main exhaust fan (15); the feed inlet of the cyclone preheater (13) is connected to the discharge outlet of the feeding device (12); the discharge outlet of the cyclone preheater (13), the air outlet of the combustion fan (16) and the fuel supply pipe are all connected to the feed end of the main burner (5).

2. The multi-chamber mineral suspension smelting system according to claim 1, characterized in that: The bottom surface of the molten pool (3) includes a central bottom surface (4) located in the middle and an annular bottom surface surrounding the outside of the central bottom surface (4); the horizontal projection of the molten chamber (1) is located inside the central bottom surface (4); the middle of the central bottom surface (4) is higher than the surrounding area and gradually decreases from the middle to the surrounding area; the annular bottom surface is horizontally arranged; the molten material outlet is opened on the annular bottom surface, and multiple molten material outlets are evenly arranged along the circumference of the annular bottom surface.

3. The multi-chamber mineral suspension smelting system according to claim 2, characterized in that: An annular molten pool dam (8) is provided on the central bottom surface (4); the horizontal projections of the central flue (2) and the molten chamber (1) are both located inside the molten pool dam (8); multiple molten material channels (9) are opened at the bottom of the molten pool dam (8).

4. The multi-chamber mineral suspension smelting system according to claim 3, characterized in that: The bottom surface of the molten pool (3) is provided with a plurality of first baffles (10) and a plurality of second baffles (11); one end of the first baffle (10) starts from the lower edge of the central flue (2), and the other end of the first baffle (10) extends radially to the inner wall of the molten pool (3), and the flow channel between two adjacent first baffles (10) is used to form a flow channel corresponding to one of the molten chambers (1); one end of the second baffle (11) starts from the outer wall of the molten pool weir (8), and the other end of the second baffle (11) extends radially to the inner wall of the molten pool (3), and the flow channel between adjacent first baffles (10) and second baffles (11), and between two adjacent second baffles (11), is used to form a flow channel corresponding to one of the molten material channels (9) and one of the molten material outlets.

5. The multi-chamber mineral suspension smelting system according to claim 3 or 4, characterized in that: The bottom of the molten pool (3) is provided with several funnel-shaped discharge channels (6), and each discharge channel (6) is evenly arranged in a ring on the outside of the molten pool dam (8); the large end of the discharge channel (6) is connected to the molten pool (3), and the small end of the discharge channel (6) forms the outlet of the molten material.

6. The multi-chamber mineral suspension smelting system according to any one of claims 1 to 5, characterized in that: The ratio of the height of the molten chamber (1) to the height of the central flue (2) is 0.6~0.8:1; the ratio of the diameter of the central flue (2) to the diameter of the molten pool (3) is 0.2~0.35:

1.

7. The multi-chamber mineral suspension smelting system according to claim 6, characterized in that: The melting chamber (1) includes an inner melting chamber (101) close to the central flue (2) and an outer melting chamber (102) away from the central flue (2), with the inner melting chamber (101) and the outer melting chamber (102) arranged alternately; the ratio of the horizontal distance from the central axis of the outer melting chamber (102) and the inner melting chamber (101) to the central axis of the central flue (2) is 1.2 to 2:

1.

8. The multi-chamber mineral suspension smelting system according to any one of claims 2 to 7, characterized in that: An annular collection trough (18) is provided between the central bottom surface (4) and the annular bottom surface. The two sides of the opening of the collection trough (18) are respectively connected to the central bottom surface (4) and the annular bottom surface. The bottom of the collection trough (18) is provided with multiple discharge ports, and each discharge port is evenly distributed along the annular bottom of the trough.

9. The multi-chamber mineral suspension smelting system according to claim 8, characterized in that: The collection trough (18) is provided with an annular overflow baffle (19) along the outer edge of the trough opening.

10. The multi-chamber mineral suspension smelting system according to claim 8 or 9, characterized in that: The lower part of the central flue (2) is provided with a reducing agent injection port, and the reducing agent injection port is evenly arranged along the circumference of the central flue (2). Alternatively, a reducing agent injection port may be provided at the upper part of the molten pool (3), and the reducing agent injection ports may be uniformly arranged along the circumference of the molten pool (3); the horizontal projection of the reducing agent injection port is located within the central bottom surface (4); Alternatively, a pair of graphite electrodes may be provided on the central bottom surface (4).

11. The multi-chamber mineral suspension smelting system according to any one of claims 2 to 10, characterized in that: The system also includes a secondary heating device; the secondary heating device is located above the annular bottom surface and is evenly distributed along the circumference of the molten pool (3); the secondary heating device is at least one of an auxiliary burner, a heating resistor and a medium-frequency induction coil.

12. The multi-chamber mineral suspension smelting system according to any one of claims 1 to 11, characterized in that: A cyclone separator is installed at the top of the central flue (2); the outlet of the cyclone separator is connected to the exhaust port.

13. The multi-chamber mineral suspension smelting system according to any one of claims 1 to 12, characterized in that: The system also includes a flue gas heat exchanger (14); the flue gas heat exchanger (14) is provided with a flue gas passage and an air passage for countercurrent heat exchange through a partition wall; the air inlet of the flue gas passage is connected to the air outlet of the cyclone preheater (13), and the air outlet of the flue gas passage is connected to the air inlet of the main exhaust fan (15); the air inlet of the air passage is connected to the air outlet of the combustion fan (16), and the air outlet of the air passage is connected to the feed end of the main burner (5).

14. The multi-chamber mineral suspension smelting system according to claim 13, characterized in that: The side wall of the central flue (2) is provided with a preheated air inlet; the preheated air inlet is connected to the air outlet of the air channel.

15. The multi-chamber mineral suspension smelting system according to any one of claims 1 to 14, characterized in that: The system also includes a downstream processing device (7); the downstream processing device (7) is located below the outlet of the molten material; the downstream processing device (7) is one of a forming device, a reduction furnace, a converter, an anode furnace, or an electrolytic cell.

16. The multi-chamber mineral suspension smelting system according to claim 15, characterized in that: The downstream processing device (7) is a wire drawing device; a stencil is provided at the outlet of the molten material; the wire drawing device is located below the stencil.

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