Metal smelting systems and metal smelting methods

Abstract

This invention provides a metal smelting system and method. The method includes the following steps: a thermal storage smelting step: the metal particles to be smelted serve as the heat-absorbing medium, receiving and storing radiant energy from a radiation source via radiative heat transfer to achieve heating; the metal particles to be smelted, heated to a specified temperature, are initially reduced by a reducing gas supplied to a heat absorber; a sensible heat smelting step: the outlet product obtained from the thermal storage smelting step is transferred to a first smelting vessel, where the sensible heat of the outlet product serves as the heat source for the continued reduction reaction, allowing any insufficiently reduced metal particles to be smelted in the outlet product to continue to be reduced. This invention reduces the amount of reducing gas used, decreases the power consumption of metal smelting, and facilitates sufficient contact and reduction between the metal particles to be smelted and the reducing gas, thereby improving the reduction rate of metal smelting.

Description

Technical Field

[0001] This invention relates to the field of metal smelting technology, specifically to a metal smelting system and a metal smelting method. Background Technology

[0002] The direct reduction process in a hydrogen shaft furnace is a key area of ​​research and development in hydrogen metallurgy both domestically and internationally. Maintaining the reduction reaction of iron ore in the shaft furnace requires an external heat source. Using hydrogen as a heat carrier and heat transfer medium is currently the main solution. However, due to the low density and specific heat capacity of hydrogen, an excessive amount of high-temperature hydrogen needs to be introduced to maintain the reaction. This leads to problems such as high hydrogen circulation volume and power consumption in the shaft furnace. At the same time, when the heat carrier hydrogen comes into contact with the iron pellets flowing counter-currently in the shaft furnace, the outermost layer of iron oxides in the pellets is rapidly reduced by the high-temperature hydrogen. At this time, the layered iron element generated on the outer layer of the pellets is prone to sintering, forming a dense spherical shell-type barrier layer, which restricts the diffusion of hydrogen to the center of the pellets and further reduction reaction, resulting in low iron reduction rate and low hydrogen utilization rate. Moreover, solar energy also has problems such as fluctuating power supply, making it difficult to stably and continuously supply energy to the reaction. Summary of the Invention

[0003] To address the above problems, this invention provides a metal smelting system and method that reduces the amount of reducing gas used, decreases the power consumption of metal smelting, and facilitates full contact and reduction between the metal particles to be smelted and the reducing gas, thereby improving the reduction rate of metal smelting.

[0004] This invention provides a metal smelting system, comprising:

[0005] A radiation source is used to provide the radiation energy required for the reduction of metal particles to be smelted.

[0006] A reducing gas supply unit is used to provide the reducing gas required for the reduction of metal particles to be smelted;

[0007] The heat absorber is connected to the outlet of the reducing gas supply mechanism. The heat absorber is used to provide heat absorption and smelting environment for the metal particles to be smelted. The metal particles to be smelted serve as the heat absorber, receiving and storing the radiant energy provided by the radiation source in the form of radiative heat transfer to achieve heating. The metal particles to be smelted, heated to the specified temperature, are initially reduced by the reducing gas.

[0008] The inlet of the first smelting vessel is connected to the outlet of the absorber. The product from the outlet of the absorber enters the first smelting vessel. The sensible heat of the product at the outlet serves as the heat source for the reduction reaction to continue, allowing the metal particles to be smelted that have not been fully reduced in the product to continue to be reduced.

[0009] According to this technical solution, a high-temperature heat source is provided for metal smelting through radiation heat transfer. Compared with other new energy gas-based metallurgy, such as photovoltaic metallurgy, which requires converting light energy into electrical energy for metallurgy, the process is shorter and consumes less energy.

[0010] The metal particles to be smelted serve as the heat-absorbing working medium in the heat absorber, absorbing radiant heat and converting it into thermal energy. At the same time, a reduction reaction occurs in the heat absorber, allowing the heat absorption and smelting of the metal particles to be smelted to occur in the same container. This simplifies the structure of the metal smelting system and shortens the metal smelting process.

[0011] The metal particles to be smelted, acting as the endothermic working medium, possess high thermal energy and serve as the primary heat carrier. Therefore, the reducing gas supplied by the reducing gas-based supply mechanism does not need to carry a large amount of thermal energy, thus eliminating the need to rely on a large amount of circulating gas to transport the heat required for reduction. This reduces the number of gas cycles and the amount of gas used, thereby lowering cycle power consumption. Furthermore, the endothermic process of the working medium causes its temperature to rise gradually and react with hydrogen at a relatively slow rate, unlike in existing technologies where the reducing gas is rapidly reduced by high-temperature hydrogen upon contact with the iron ore pellets. This avoids the formation of an obstruction layer on the surface of the metal particles to be smelted, thereby ensuring the ability of the reducing gas to diffuse towards the center of the metal particles and further reduce them.

[0012] The metal particles to be smelted can be used as an endothermic working medium to heat up to a specified temperature, and a reduction reaction can be directly carried out, which shortens the smelting time and smelting process.

[0013] Furthermore, by setting up a first smelting container, the outlet product can be transferred without continuously occupying the heat absorber. This allows the incompletely reduced metal particles to be smelted to continue to be reduced under the action of sensible heat within the first smelting container. This overcomes the problem of mismatch between heat storage and reduction reaction time, improves material turnover efficiency and smelting efficiency, and realizes the utilization of sensible heat, which is conducive to energy saving.

[0014] Furthermore, compared to other heat storage media, the metal particles to be smelted, as the heat-absorbing medium, possess a large heat storage capacity and a high heat storage temperature. When the radiant energy is fluctuating (such as sunlight) and experiences significant fluctuations, using the metal particles to be smelted for heat storage prevents drastic temperature changes in the metal particles due to these fluctuations. Converting fluctuating radiant energy into the heat energy of the metal particles eliminates the volatility of radiant energy, achieving a transformation from unstable energy to stable heat energy. This allows the smelting process to proceed under relatively stable temperature conditions, ensuring the temperature stability of the metal particles and smelting efficiency, which is beneficial for improving the reduction rate. Moreover, the reduction reaction of the metal particles is an endothermic process, which can, to some extent, balance the temperature fluctuations of the metal particles when absorbing fluctuating radiant energy for heat storage, ensuring the temperature stability of the metal particles. When the radiant energy is non-fluctuating, the metal particles can uniformly absorb radiant energy, store heat, and be reduced, ensuring the quality of the smelting and contributing to a higher reduction rate.

[0015] In an optional technical solution of the present invention, the energy flux density of the radiation energy is configured such that the heating rate of the metal particles to be smelted is not lower than the heat absorption rate when the metal particles to be smelted are reduced.

[0016] According to this technical solution, by controlling the energy flux density of radiation energy, the heating rate of the metal particles to be smelted is ensured to be no less than the heat absorption rate when the metal particles to be smelted are reduced, so that the temperature of the metal particles to be smelted is always no less than the temperature required for the reduction reaction, ensuring that the reduction reaction continues and improving smelting efficiency.

[0017] In an optional technical solution of the present invention, the outlet of the reducing gas-based supply mechanism is configured to correspond to the outlet of the absorber. The reducing gas-based supply mechanism includes: a flow regulating valve for regulating the outlet flow rate of the reducing gas; and a flow meter connected to the flow regulating valve. The flow meter is configured to detect the flow rate of the reducing gas and control the opening degree of the flow regulating valve according to the flow rate of the reducing gas.

[0018] According to this technical solution, the reducing gas from the outlet of the reducing gas-based supply mechanism enters through the outlet of the receiver, creating a counter-current flow with the metal particles to be smelted. This increases the contact area between the reducing gas and the metal particles, promoting thorough reduction. Furthermore, by controlling the flow rate of the reducing gas in real time, the rate of the reduction reaction within the receiver can be controlled, effectively balancing fluctuations in radiant energy. It also allows the flow rate of the reducing gas to match the flow velocity of the metal particles to be smelted, reducing the amount of reducing gas used and increasing its utilization rate.

[0019] In the optional technical solutions of the present invention, the heat absorber is a fluidized bed type solid particle heat absorber, a free-falling solid particle heat absorber, an inclined plane sliding particle heat absorber, or a curtain type particle heat absorber.

[0020] According to this technical solution, commercially available fluidized bed solid particle heat absorbers, free-fall solid particle heat absorbers, inclined plane sliding particle heat absorbers, or curtain-type particle heat absorbers can be used as heat absorbers, making the metal smelting system easier to manufacture and improving the convenience of its operation. Preferably, the metal particles to be smelted within the heat absorber are fluidized, thereby increasing the disturbance of the metal particles and improving the uniformity of their absorption of radiant energy. This helps ensure the temperature uniformity of the metal particles and promotes the occurrence of reduction reactions.

[0021] In an optional embodiment of the present invention, the metal smelting system further includes:

[0022] The first storage tank has its inlet connected to the outlet of the heat absorber, and the outlet product is diverted to the first smelting vessel and the first storage tank.

[0023] A medium supply mechanism for providing gaseous heat exchange media;

[0024] The inlet pipeline is connected at both ends to the outlet of the medium supply mechanism and the first storage tank, respectively;

[0025] The heat exchange pipeline connects the first smelting vessel and the first storage tank.

[0026] The outlet pipeline is connected to the first smelting vessel.

[0027] According to the technical solution, the gas heat exchange medium provided by the gas supply mechanism enters the first storage tank through the inlet pipeline and rises in temperature after exchanging heat with the product in the first storage tank. The gas after heat exchange enters the first smelting container, which can provide the heat required for the reduction of the product in the first smelting container, which is beneficial to improving the reduction rate of metal particles in the first smelting container.

[0028] The present invention further provides a metal smelting method utilizing the above-described metal smelting system, comprising the following steps:

[0029] Thermal storage smelting steps: The metal particles to be smelted serve as the heat-absorbing working medium, receiving and storing the radiant energy provided by the radiation source in the form of radiative heat transfer to achieve temperature rise; the metal particles to be smelted, heated to the specified temperature, are initially reduced by reducing gas supplied to the heat absorber.

[0030] Sensible heat smelting step: The effluent obtained from the thermal storage smelting step is transferred to the first smelting vessel. The sensible heat of the effluent is used as the heat source for the reduction reaction to continue, so that the metal particles to be smelted that have not been fully reduced in the effluent can continue to be reduced.

[0031] According to this technical solution, a high-temperature heat source is provided for metal smelting through radiative heat transfer. Compared to other new energy gas-based metallurgy, such as photovoltaic metallurgy which requires converting light energy into electrical energy for smelting, this method has a shorter process flow, more stable energy supply, and fewer energy conversion processes, thus reducing heat loss. The metal particles to be smelted, acting as the endothermic medium, absorb heat to a specified temperature and can directly undergo a reduction reaction, shortening smelting time and simplifying the smelting process. Furthermore, the metal particles, acting as the endothermic medium, absorb radiant energy and convert it into heat energy, serving as the heat carrier (carrying the heat required for reduction). This eliminates the need for a large amount of circulating gas to transport the heat required for smelting, reducing the number of gas cycles, lowering circulation power consumption, and promoting the reduction reaction, thereby increasing the reduction rate. In addition, by transferring the product, the sensible heat of the outlet product allows the metal particles to be smelted to continue to be reduced, overcoming the mismatch between heat storage and reduction reaction time, and improving material turnover efficiency and smelting efficiency.

[0032] In the optional technical solutions of the present invention,

[0033] The reducing gas is hydrogen.

[0034] The metal particles to be smelted are one or more of the metal oxide particles of copper, manganese, iron, tungsten, molybdenum, and germanium.

[0035] According to this technical solution, using hydrogen for metal smelting can reduce carbon emissions. When hydrogen is used as a reducing agent to reduce the aforementioned metal oxide particles, it not only absorbs a large amount of heat, but each mole of hydrogen also produces an equal amount of water vapor. By adjusting the hydrogen inlet rate / flow rate, the proportion of hydrogen and water vapor in the reaction atmosphere can be controlled, thereby regulating the rate of hydrogen reduction of iron and the heat absorption of the reaction within the reaction chamber. This achieves the goal of matching fluctuating radiant energy and maintaining a stable temperature within the absorber. Metal oxide particles such as copper, manganese, iron, tungsten, molybdenum, and germanium have a high absorption rate for radiant energy. The absorbed radiant energy is converted into high-temperature heat energy and used as the heat energy required for the reduction reaction, making it easier to meet the heat energy requirements of the reduction reaction.

[0036] In an optional technical solution of the present invention, the particle size of the metal particles to be smelted in the thermal storage smelting step is 50-500µm.

[0037] According to this technical solution, by controlling the particle size of the metal particles within a reasonable range, it is beneficial to improve the metal particles' ability to receive radiation energy, thereby ensuring that the heating temperature of the metal particles can meet the conditions for the reduction reaction to occur, thus improving the efficiency of the reduction reaction, that is, improving the efficiency of metal smelting.

[0038] In an optional embodiment of the present invention, the metal smelting system further includes:

[0039] The first storage tank has its inlet connected to the outlet of the heat absorber, and the outlet product is diverted to the first smelting vessel and the first storage tank.

[0040] A medium supply mechanism for providing gaseous heat exchange media;

[0041] The inlet pipeline is connected at both ends to the outlet of the medium supply mechanism and the first storage tank, respectively;

[0042] The heat exchange pipeline connects the first smelting vessel and the first storage tank.

[0043] The outlet pipeline is connected to the first smelting vessel;

[0044] Metal smelting methods also include:

[0045] Heat exchange steps: The gaseous heat exchange medium provided by the medium supply mechanism is introduced into the first storage tank through the inlet pipeline, and the gaseous heat exchange medium exchanges heat with the outlet product in the first storage tank;

[0046] Reheating step: In the heat exchange step, the gaseous heat exchange medium after heat exchange enters the first smelting vessel through the heat exchange pipeline. The temperature of the outlet product in the first smelting vessel increases after heat exchange with the gaseous heat exchange medium.

[0047] According to this technical solution, by exchanging heat between the gas heat exchange medium and a portion of the outlet product generated by the diversion, the gas heat exchange medium is heated, and the heated gas heat exchange medium is introduced into the first smelting container to provide the heat required for reduction. This helps to ensure the heat required for the reduction reaction in the first smelting container and improve the reduction rate of the metal particles to be smelted in the first smelting container.

[0048] In an optional technical solution of the present invention, the following is further performed after the heat exchange step:

[0049] Circulating smelting step: The heat exchanged product from the first storage tank is supplied to the heat absorber for heat storage smelting.

[0050] According to this technical solution, by performing a cyclic smelting step, the insufficiently reduced export product can be further reduced, thereby improving the reduction rate of metal smelting. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of the metal smelting system in the first embodiment of the present invention.

[0052] Figure 2 This is a schematic diagram of the metal smelting method in the first embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of the metal smelting system in the second embodiment of the present invention.

[0054] Figure label:

[0055] Radiation source 1; reducing gas supply mechanism 2; flow regulating valve 21; heat absorber 3; feed inlet 31; discharge outlet 32; bottom wall 33; guide slope 331; radiation energy inlet 34; first smelting vessel 4; gas inlet pipe 41; gas outlet pipe 42; feed silo 5; first storage tank 6; inlet pipe 71; heat exchange pipe 72; outlet pipe 73. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] like Figure 1 As shown, this embodiment provides a metal smelting system, including: a radiation source 1 (specifically a light source), a reducing gas supply mechanism 2, a heat absorber 3, and a first smelting container 4. Specifically, the radiation source 1 is used to provide the radiation energy required for the reduction of the metal particles to be smelted. The reducing gas supply mechanism 2 is used to provide the reducing gas required for the reduction of the metal particles to be smelted. The heat absorber 3 is connected to the outlet of the reducing gas supply mechanism 2, and the heat absorber is used to provide a heat absorption and smelting environment for the metal particles to be smelted. The heat absorber 3 contains the metal particles to be smelted, which also serve as the heat-absorbing working fluid, receiving and storing the radiation energy provided by the radiation source in the form of radiative heat transfer to achieve heating; the metal particles to be smelted, heated to a predetermined temperature, are initially reduced by the reducing gas; the predetermined temperature is the temperature at which the metal particles to be smelted undergo a reduction reaction with the reducing gas. The inlet of the first smelting vessel 4 is connected to the outlet of the absorber 3. The product from the outlet of the absorber 3 enters the first smelting vessel 4. The sensible heat of the product is used as the heat source for the reduction reaction to continue, so that the metal particles to be smelted that have not been fully reduced in the product can continue to be reduced.

[0058] In this embodiment, a high-temperature heat source is provided for metal smelting through radiation heat transfer. Compared with other new energy gas-based metallurgy, such as photovoltaic metallurgy, which requires converting light energy into electrical energy for metallurgy, the process is shorter and consumes less energy.

[0059] The metal particles to be smelted serve as both the working medium to be smelted and the heat-absorbing working medium in the heat absorber 3. They absorb radiant heat and convert it into thermal energy in the heat absorber 3, while a reduction reaction occurs in the heat absorber 3. This allows the heat absorption and smelting of the metal particles to be smelted to occur in the same container, simplifying the structure of the metal smelting system and shortening the metal smelting process.

[0060] The metal particles to be smelted, acting as the endothermic working medium, possess high thermal energy and serve as the primary heat carrier. Therefore, the reducing gas supplied by the reducing gas-based supply mechanism does not need to carry a large amount of thermal energy, thus eliminating the need to rely on a large amount of circulating gas to transport the heat required for reduction. This reduces the number of gas cycles and the amount of gas used, thereby lowering cycle power consumption. Furthermore, the endothermic process of the working medium causes its temperature to rise gradually and react with hydrogen at a relatively slow rate, unlike in existing technologies where the reducing gas is rapidly reduced by high-temperature hydrogen upon contact with the iron ore pellets. This avoids the formation of an obstruction layer on the surface of the metal particles to be smelted, thereby ensuring the ability of the reducing gas to diffuse towards the center of the metal particles and further reduce them.

[0061] The metal particles to be smelted can be used as an endothermic working medium to heat up to a specified temperature, and a reduction reaction can be directly carried out, which shortens the smelting time and smelting process.

[0062] Furthermore, by setting up a first smelting container 4, the outlet product can be transferred without continuously occupying the heat absorber 3. This allows the incompletely reduced metal particles to be smelted to continue to be reduced under the action of sensible heat within the first smelting container 4. This overcomes the problem of mismatch between heat storage and reduction reaction time (for example, it takes 40 minutes for iron ore heat-absorbing particles to be heated to 1000℃, while it takes 90 minutes for its complete reduction reaction. After transferring the iron ore heat-absorbing particles, the reaction can continue using sensible heat, thus improving the reduction efficiency). This improves the turnover efficiency of materials and smelting efficiency, and realizes the utilization of sensible heat, which is beneficial for saving energy.

[0063] Furthermore, compared to other heat storage media, the metal particles to be smelted, as the heat-absorbing medium, possess a large heat storage capacity and a high heat storage temperature. When the radiant energy is fluctuating (such as sunlight) and experiences significant fluctuations, using the metal particles to be smelted for heat storage prevents drastic temperature changes in the metal particles due to these fluctuations. Converting fluctuating radiant energy into the heat energy of the metal particles eliminates the volatility of radiant energy, achieving a transformation from unstable energy to stable heat energy. This allows the smelting process to proceed under relatively stable temperature conditions, ensuring the temperature stability of the metal particles and smelting efficiency, which is beneficial for improving the reduction rate. Moreover, the reduction reaction of the metal particles is an endothermic process, which can, to some extent, balance the temperature fluctuations of the metal particles when absorbing fluctuating radiant energy for heat storage, ensuring the temperature stability of the metal particles. When the radiant energy is non-fluctuating, the metal particles can uniformly absorb radiant energy, store heat, and be reduced, ensuring the quality of the smelting and contributing to a higher reduction rate.

[0064] In a preferred embodiment of the present invention, the radiation source 1 can emit radiation energy with a high energy flux density. When the metal particles to be smelted receive radiation energy with a high energy flux density, the internal heat transfer temperature difference of the particles can be increased, the heat transfer process can be strengthened, and the efficient reduction of the metal particles to be smelted can be promoted.

[0065] Specifically, the radiation energy provided by radiation source 1 mainly includes light radiation and / or thermal radiation. Taking light radiation as an example, radiation source 1 includes sunlight and / or a focused simulated lamp. When radiation source 1 is sunlight, the sunlight radiates onto the surface of the metal particles to be smelted, increasing the temperature of the metal particles, improving the utilization rate of solar energy, and saving smelting costs. Furthermore, a concentrating device (not shown in the figure) can be installed to focus sunlight onto the radiation energy inlet 34 of the heat absorber 3 to improve the light reception efficiency and the heat absorption efficiency of the heat-absorbing working fluid.

[0066] When sunlight is insufficient, a focused simulated lamp can be used to emit light, improving the applicability of the metal smelting system. Specifically, the focused simulated lamp includes multiple xenon lamps (e.g., 14) and a simulated lamp controller, used to emit incident energy flow to the heat absorber 3. The focused simulated lamp can be adjusted in focal length and pointing point to ensure that the emitted incident energy flow is at the optimal incident energy flow position, thereby improving the heat absorption efficiency and heat absorption temperature of the heat-absorbing medium. This invention does not limit the specific configuration of the focused simulated lamp; technicians can adjust it according to actual needs. In addition to the focused simulated lamp and sunlight, high-temperature radiation sources, other visible light radiation sources, electromagnetic microwaves, or other non-visible electromagnetic radiation sources or particle radiation sources can also be used to provide high energy flow density radiation energy; this embodiment does not limit this.

[0067] In this embodiment, the energy flux density of the radiation energy is configured such that the heating rate of the metal particles to be smelted is not lower than the heat absorption rate during the reduction of the metal particles. By controlling the energy flux density of the radiation energy to ensure that the heating rate of the metal particles to be smelted is not lower than the heat absorption rate during the reduction of the metal particles, the temperature of the metal particles to be smelted is always not lower than the temperature required for the reduction reaction, ensuring that the reduction reaction continues continuously and improving smelting efficiency. Preferably, the energy flux density of the radiation energy is 79-95 KW / m³. 2By controlling the energy flux density of radiation energy within a suitable range, the heating rate and temperature of the metal particles to be smelted can be ensured, so that the heating rate is higher than the endothermic rate of the reduction reaction, and the heating temperature reaches a temperature not lower than that required for the reduction reaction within a specified time, thus ensuring the progress of the reduction reaction and improving smelting efficiency. It should be noted that technicians can adjust the energy flux density of radiation energy according to the temperature range required for the reduction reaction, and are not limited to the energy flux density exemplified in this embodiment. This embodiment does not limit the method of controlling the energy flux density. For example, when radiation source 1 is sunlight, the energy flux density can be adjusted by changing the angle of the solar concentrator; when radiation source 1 is a spotlight, the intensity of the spotlight can be adjusted to change its energy flux density.

[0068] In a preferred embodiment of the present invention, the reducing gas-based supply mechanism 2 includes a flow regulating valve 21 and a flow meter (not shown in the figure). The flow regulating valve 21 is used to regulate the outlet flow rate of the reducing gas. The flow meter is connected to the flow regulating valve 21 and is configured to detect the flow rate of the reducing gas and control the opening degree of the flow regulating valve 21 according to the flow rate of the reducing gas. By controlling the flow rate of the reducing gas in real time, the rate of reduction reaction in the absorber can be controlled, effectively balancing the fluctuation of radiant energy. Furthermore, the flow rate of the reducing gas can be matched with the flow rate of the metal particles to be smelted, ensuring a sufficient reaction between the metal particles and the reducing gas, while reducing the amount of reducing gas used and improving the utilization rate of the reducing gas.

[0069] In a preferred embodiment of the present invention, the heat absorber 3 is a fluidized bed solid particle heat absorber, a free-fall solid particle heat absorber, an inclined slide-down particle heat absorber, or a curtain-type particle heat absorber. By using the heat absorption chamber of a commercially available fluidized bed solid particle heat absorber, a free-fall solid particle heat absorber, an inclined slide-down particle heat absorber, or a curtain-type particle heat absorber as the heat absorber 3, the metal smelting system is easier to process and manufacture, improving the convenience of metal smelting.

[0070] Specifically, such as Figure 1 As shown, the absorber 3 is a free-falling solid particle absorber. The absorber 3 has an inlet 31 at its upper end and an outlet 32 ​​at its lower end. The bottom wall 33 of the absorber 3 has a guide slope 331 for guiding the mixture downwards, and a radiation energy inlet 34 is provided on the side wall opposite to the guide slope 331. The outlet of the reducing gas supply mechanism 2 is correspondingly located to the outlet 32 ​​of the absorber 3. The reducing gas supplied by the reducing gas supply mechanism 2 flows counter-currently to the metal particles to be smelted, ensuring thorough mixing of the metal particles and the reducing gas, increasing the reaction area, and improving reaction efficiency.

[0071] In this embodiment, the absorber 3 provides a site where radiant energy is converted into heat energy and the reduction reaction occurs simultaneously. The absorber 3 has a simple structure, is easy to implement, and helps save operating costs. Furthermore, it simplifies the smelting system structure, shortens the smelting process flow, and improves smelting efficiency.

[0072] Furthermore, the inclined guide surface 331 allows the mixture to undergo preliminary smelting by flowing under gravity, improving the efficiency and uniformity of radiation energy reception and enhancing the reduction rate. Specifically, high-energy-flux-density radiation heats the surface of the spherical metal particles, causing a reduction reaction in the surface and localized areas. As the metal particles roll, other localized areas are gradually heated by radiation and undergo reduction reactions, ensuring a high reduction rate for the iron ore particles. In some embodiments, the mixture is not limited to being conveyed via the absorber 3 with the inclined guide surface 331; other mechanisms capable of conveying the granular mixture in a fluidized state are also applicable to this embodiment, and this application does not limit the scope of the application.

[0073] Optionally, by controlling the inclination angle and length of the guide slope 331, the flow rate and residence time of the material in the absorber 3 can be controlled, allowing the metal particles to be smelted to undergo sufficient preliminary smelting within the absorber 3. Preferably, the temperature of the product at the outlet of the absorber 3 should be within a reasonable temperature range, ensuring that after the product is transferred from the absorber 3, the unreduced metal particles can be reduced under the sensible heat of the product itself, thereby improving the reduction rate. Optionally, the flow rate of the material can also be controlled by controlling the roughness of the guide slope 331. Preferably, the material that first contacts the radiation source 1 is preferentially discharged from the outlet 32, ensuring that the material in the absorber 3 can undergo uniform preliminary reduction, thereby improving smelting efficiency. Technicians can adjust the setting position and opening of the outlet 32 ​​according to actual conditions; this embodiment does not limit this.

[0074] The radiant inlet 34 facilitates the passage of radiant energy such as light, improving the heating efficiency of the mixture. Furthermore, gases generated during the reduction reaction can also be discharged through the radiant inlet 34. In some embodiments, the radiant inlet 34 may not be an open structure; for example, it can be a transparent cover with a perforated structure, allowing the passage of radiant energy such as light and the discharge of gases.

[0075] In a preferred embodiment of the present invention, a discharge gate valve (not shown in the figure) is provided at the discharge port 32 of the heat absorber 3 to control the outlet flow rate of the metal particles to be smelted in the heat absorber 3 to ensure that the metal particles to be smelted fully absorb heat and are reduced.

[0076] It should be noted that, in this embodiment, the product at the outlet of the heat absorber 3 specifically includes a mixture of metal particles to be smelted, elemental metal, and reducing agent particles.

[0077] In a preferred embodiment of the present invention, the metal smelting system further includes: a feed hopper 5 and a feed gate valve (not shown in the figure). The feed hopper 5 is used to temporarily store the metal particles to be smelted, and the outlet of the feed hopper 5 is connected to the inlet 31 of the absorber 3. The feed gate valve is located at the outlet of the feed hopper 5 and is used to control the thickness and flow rate of the metal particles to be smelted flowing into the absorber 3 through the feed hopper. By setting the feed hopper 5 and the feed gate valve, the amount of metal particles to be smelted entering the absorber 3 can be adjusted according to the actual working conditions, which is beneficial to ensure that the metal particles to be smelted in the absorber 3 are in full contact with the reducing gas, thereby improving the smelting quality.

[0078] In optional embodiments, there are multiple first smelting containers 4, and the inlets of each of the multiple first smelting containers 4 can be correspondingly set to the outlets of the absorbers 3. The multiple first smelting containers 4 can be used alternately; when one of the first smelting containers 4 is full of product, another first smelting container 4 is moved to the outlet 32 ​​of the absorber 3 to receive the discharged product. Preferably, the metal smelting system further includes an inlet pipe 41 and an outlet pipe 42, which are respectively connected to the first smelting containers 4. Reducing gas is supplied to the first smelting containers 4 through the inlet pipe 41 to replenish the reducing gas required for the reduction of the metal particles to be smelted in the first smelting containers 4, which is beneficial for promoting the reduction rate. Similarly, a flow regulating valve can be provided on the inlet pipe 41 to regulate the flow rate of the reducing gas. In some embodiments, the reducing gas supply mechanism 2 can supply reducing gas to both the first smelting containers 4 and the absorbers 2 simultaneously, or it can supply reducing gas to both the first smelting containers 4 and the absorbers 2 separately; this application does not limit this.

[0079] Corresponding to the above-mentioned metal smelting system, such as Figure 2 As shown, this embodiment provides a metal smelting method, including the following steps:

[0080] Thermal storage smelting steps: The metal particles to be smelted serve as the heat-absorbing working medium, receiving and storing the radiant energy provided by the radiation source in the form of radiative heat transfer to achieve temperature rise; the metal particles to be smelted, heated to the specified temperature, are initially reduced by the reducing gas supplied to the heat absorber 3; the specified temperature is the temperature at which the metal particles to be smelted react with the reducing gas.

[0081] Sensible heat smelting step: The effluent obtained from the heat storage smelting step is transferred to the first smelting vessel 4. The sensible heat of the effluent is used as the heat source for the reduction reaction to continue, so that the metal particles to be smelted that have not been fully reduced in the effluent can continue to be reduced.

[0082] In this embodiment, a high-temperature heat source is provided for metal smelting through radiative heat transfer. Compared to other new energy gas-based metallurgy, such as photovoltaic metallurgy which requires converting light energy into electrical energy for smelting, this method has a shorter process flow, more stable energy supply, and fewer energy conversion processes, thus reducing heat loss. The metal particles to be smelted, acting as the heat-absorbing medium, absorb heat to a specified temperature and can directly undergo a reduction reaction, shortening the smelting time and simplifying the smelting process. Furthermore, the metal particles to be smelted, acting as the heat-absorbing medium, absorb radiant energy and convert it into heat energy, serving as the heat carrier (carrying the heat required for reduction). This eliminates the need for a large amount of circulating gas to transport the heat required for smelting, reducing the number of gas cycles, lowering circulation power consumption, and promoting the occurrence of the reduction reaction, thereby increasing the reduction rate. In addition, by transferring the product, the sensible heat of the outlet product allows the metal particles to be smelted to continue to be reduced, overcoming the problem of mismatch between heat storage and reduction reaction time, and improving material turnover efficiency and smelting efficiency.

[0083] In this embodiment, the metal particles to be smelted enter the absorber 3 from the feed bin 5. The outlet 32 ​​of the absorber 3 is always open. Due to the inclined structure of the guide slope 331, the metal particles to be smelted on the guide slope 331 can undergo preliminary reduction in a dynamic manner under the action of the component of gravity. The product moving to the outlet 32 ​​of the absorber 3 can be continuously discharged. The dynamic metal particles are conducive to sufficient contact with the radiation source for heating and sufficient contact with the reducing gas for reduction, thereby improving the heating uniformity and reduction efficiency of the metal particles to be smelted.

[0084] In a preferred embodiment of the present invention, the reducing gas is hydrogen. Using hydrogen for metal smelting can reduce carbon emissions; when hydrogen is used as a reducing agent to reduce the aforementioned metal oxide particles, it not only absorbs a large amount of heat, but also produces an equal amount of water vapor per mole of hydrogen. By adjusting the hydrogen inlet rate / flow rate, the proportion of hydrogen and water vapor in the reaction atmosphere can be controlled, thereby adjusting the rate of hydrogen reduction of iron in the reaction chamber and the heat absorption of the reaction, achieving the purpose of matching fluctuating radiant energy and maintaining a stable temperature inside the absorber.

[0085] In a preferred embodiment of the present invention, the metal particles to be smelted are one or more of the metal oxide particles of copper, manganese, iron, tungsten, molybdenum, and germanium. Metal oxide particles such as copper, manganese, iron, tungsten, molybdenum, and germanium have a darker color and a higher absorption rate for radiation source 1 (such as light within the visible wavelength range of sunlight). For example, iron ore particles (Fe2O3, Fe3O4, FeO) have an absorption rate of nearly 90% for light within the visible wavelength range of solar energy and can be directly used as an endothermic working fluid. Furthermore, the heating rate of iron ore particles can reach 27.6 K / min under sunlight irradiation. The heating rate of iron ore particles is higher than the reaction rate between iron ore particles and reducing gases, resulting in a higher heat supply than endothermic reaction, ensuring the continuous and efficient progress of the reaction.

[0086] It should be noted that the metal particles to be smelted are not limited to copper, manganese, iron, tungsten, molybdenum, and germanium. Other metal oxides with good absorption rates to radiation source 1 are also suitable for smelting using the metal smelting method provided by this invention. In this embodiment, the metal particles to be smelted can be obtained from the ore to be smelted through crushing and screening, but are not limited to this.

[0087] In a preferred embodiment of the present invention, the particle size of the metal particles to be smelted is 50-500 µm. By controlling the particle size of the metal particles to be smelted within a reasonable range, it is beneficial to improve the absorption performance of the metal particles to be smelted for radiation energy, thereby ensuring that the heating temperature and heating rate of the metal particles to be smelted can meet the conditions for the reduction reaction to occur, thus improving the efficiency of the reduction reaction, that is, improving the efficiency of metal smelting. Further, in an embodiment of the present invention, the particle size of the metal particles to be smelted is 70-100 µm. It should be noted that those skilled in the art can adjust the particle size of the metal particles to be smelted according to actual needs, and are not limited to the examples given in this embodiment.

[0088] In a preferred embodiment of the present invention, the metal smelting method further includes: when the first smelting container 4 is full of product, removing the first smelting container 4 and moving a spare first smelting container 4 to a position corresponding to the outlet of the absorber 3 to continue receiving the product from the outlet of the absorber 3. Alternating use of multiple first smelting containers 4 helps ensure the continuous operation of the smelting process.

[0089] In a preferred embodiment of the present invention, the metal smelting method further includes:

[0090] By controlling the opening of the electric gate valve at the outlet of the feed hopper 5, the thickness and flow rate of the metal particles to be smelted at the inlet of the heat absorber 3 are controlled, ensuring that the metal particles to be smelted absorb heat fully and uniformly.

[0091] Control the opening of the electric gate valve at the outlet of the absorber 3 to adjust the residence time and flow rate of the metal particles to be smelted in the absorber 3, so as to ensure that the metal particles to be smelted absorb heat fully and evenly, and to ensure the duration of the reduction reaction.

[0092] The structure and smelting method of the metal smelting system in the embodiments of the present invention have been described above. The following uses iron ore particles as the metal particles and reducing gas as the reducing agent as an example to illustrate its smelting method.

[0093] The metal particles to be smelted can be heated to 600-1000℃ after receiving radiation energy, which meets the temperature conditions for the reduction reaction between the reducing gas and the iron ore particles. The iron ore particles and the reducing gas are added to the feed hopper 5. Due to gravity, the iron ore particles flow from the outlet of the feed hopper 5 into the heat absorber 3. The radiation source 1 emits high-concentration incident energy into the heat absorber 3. The iron ore particles in the heat absorber 3 can reach a heating rate of 27.6K / min after receiving heat from the heat source, which is higher than the heat absorption rate of the reaction between the iron ore particles and the reducing gas. At the same time, the iron ore particles, as the heat absorption and storage medium, can reach a high temperature of about 950℃ after receiving radiation from the radiation source 1, which meets the reduction reaction temperature of the iron ore particles, that is, the reduction reaction occurs with the reducing gas in the heat absorber 3.

[0094] Furthermore, the outlet temperature of the iron ore particles can reach as high as about 950℃. The unreacted iron ore particles flow into the first smelting container 4 due to gravity. The iron ore particles carry heat into the first smelting container 4, and the main component of the iron ore particles is Fe2O3. Since the specific heat capacity of Fe2O3 at 1000℃ is 0.88KJ / (kg·℃), Fe2O3 releases 352kJ / kg of heat when its temperature drops by 400℃. The released heat meets the heat required for the reaction, which can ensure that the iron ore particles can further react with the reducing gas continuously and efficiently, thus ensuring that the iron ore particles have a high reduction rate.

[0095] Furthermore, after the first smelting container 4 is filled with the fully reacted iron ore particles, it can be completely poured out, and then the spare first smelting container 4 can take over its use. The spare first smelting container 4 continues to receive the product flowing out of the absorber 3. The alternating use of multiple first smelting containers 4 can realize the smelting cycle.

[0096] [Second Implementation Method]

[0097] like Figure 3 As shown, the third embodiment of the present invention provides a metal smelting system. The third embodiment is a further improvement on the first embodiment. Unless otherwise specified, the reference numerals and text descriptions are the same as those in the first embodiment and will not be repeated here.

[0098] In a third embodiment of the present invention, the metal smelting system further includes: a first storage tank 6, a medium supply mechanism (not shown in the figure), an inlet pipe 71, a heat exchange pipe 72, and an outlet pipe 73. The inlet of the first storage tank 6 is connected to the outlet 32 ​​of the heat absorber 3. The medium supply mechanism is used to provide the heat exchange medium. The two ends of the inlet pipe 71 are connected to the outlet of the medium supply mechanism and the first storage tank 6, respectively. The heat exchange pipe 72 is connected to the first smelting container 4 and the first storage tank 6. The outlet pipe 73 is connected to the first smelting container 4.

[0099] In the above manner, the heat exchange medium provided by the medium supply mechanism enters the first storage tank 6 through the inlet pipe 71, and its temperature rises after exchanging heat with the product in the first storage tank 6. The gas after heat exchange enters the first smelting container 4, which can provide the heat required for the reduction of the product in the first smelting container 4, thus improving the reduction rate of the metal particles to be smelted in the first smelting container 4. In this embodiment of the invention, the gaseous heat exchange medium is H2. H2 absorbs the heat from the high-temperature particles in the first storage tank 6 and rises in temperature, supplementing the heat required for the reduction of the metal particles to be smelted in the first smelting container 4. Furthermore, H2 can also participate in the reduction reaction as a reducing agent, ensuring the normal progress of the reduction reaction and thus improving the reduction rate.

[0100] Correspondingly, this embodiment provides a metal smelting method. Unless otherwise specified, the parts including the reference numerals and text descriptions are the same as those in the first embodiment, and will not be repeated here.

[0101] The metal smelting method of this embodiment further includes: introducing a gaseous heat exchange medium H2 into the first storage tank 6 through the inlet pipe 71; the gaseous heat exchange medium in the first storage tank 6 is heated by the sensible heat released by the high-temperature products; the heated gaseous heat exchange medium enters the first smelting container 4 through the heat exchange pipe 72; the metal particles to be smelted in the first smelting container 4 receive heat replenishment from the gaseous heat exchange medium in the heat exchange pipe 72 and a replenishment of the reducing agent, allowing the metal particles to undergo a continuous reduction reaction and improving the reduction rate of the metal particles to be smelted. Furthermore, the cooled metal particles to be smelted in the first storage tank 6 can be reintroduced into the silo 5 to achieve re-smelting of the metal particles to be smelted, thereby improving the reduction rate.

[0102] In a preferred embodiment of the present invention, the metal smelting method further includes:

[0103] Heat exchange steps: The gaseous heat exchange medium provided by the medium supply mechanism is introduced into the first storage tank 6 through the inlet pipe 71, and the gaseous heat exchange medium exchanges heat with the outlet product in the first storage tank 6.

[0104] Reheating step: In the heat exchange step, the gas heat exchange medium after heat exchange enters the first smelting vessel 4 through the heat exchange pipeline 72. The temperature of the outlet product in the first smelting vessel 4 increases after heat exchange with the gas heat exchange medium after heat exchange.

[0105] In a preferred embodiment of the present invention, the metal smelting method further includes, after the heat exchange step, performing a circulating smelting step: supplying the heat-exchanged outlet product in the first storage tank 6 to the heat absorber 3 for a heat storage smelting step. By performing the circulating smelting step, the insufficiently reduced outlet product can be further reduced, thereby improving the reduction rate of metal smelting.

[0106] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metal smelting system, characterized in that, include: A radiation source is used to provide the radiation energy required for the reduction of metal particles to be smelted. A reducing gas supply unit is used to provide the reducing gas required for the reduction of the metal particles to be smelted; The heat absorber is connected to the outlet of the reducing gas-based supply mechanism. The heat absorber is used to provide heat absorption and a smelting environment for the metal particles to be smelted. The metal particles to be smelted serve as the heat-absorbing working medium, receiving and storing the radiant energy provided by the radiation source in the form of radiative heat transfer to achieve heating. The metal particles to be smelted, heated to a specified temperature, are initially reduced by the reducing gas. The heat absorber is an inclined sliding particle heat absorber or a curtain-type particle heat absorber. The upper end of the heat absorber is provided with a feed inlet, the lower end of the heat absorber is provided with a discharge outlet, the bottom wall of the heat absorber has a guide slope for guiding the mixture to slide down, and the side wall of the heat absorber opposite to the guide slope is provided with a radiation energy inlet. The inlet of the first smelting vessel is connected to the outlet of the heat absorber. The product from the outlet of the heat absorber enters the first smelting vessel. The sensible heat of the product is used as a heat source for the reduction reaction to continue, so that the metal particles to be smelted that have not been fully reduced in the product can continue to be reduced. The outlet of the reducing gas-based supply mechanism is configured to correspond to the outlet of the absorber, and the reducing gas-based supply mechanism includes: A flow regulating valve is used to regulate the outlet flow rate of the reducing gas; A flow meter is connected to the flow regulating valve. The flow meter is configured to detect the flow rate of the reducing gas and control the opening degree of the flow regulating valve based on the flow rate of the reducing gas.

2. The metal smelting system according to claim 1, characterized in that, The energy flux density of the radiation energy is configured such that the heating rate of the metal particles to be smelted is not lower than the heat absorption rate when the metal particles to be smelted are reduced.

3. The metal smelting system according to claim 1, characterized in that, The metal smelting system also includes: The first storage tank has an inlet connected to the outlet of the heat absorber, and the outlet product is diverted to the first smelting vessel and the first storage tank. A medium supply mechanism for providing gaseous heat exchange media; The inlet pipe is connected at both ends to the outlet of the medium supply mechanism and the first storage tank, respectively; Heat exchange pipelines connect the first smelting vessel and the first storage tank; The outlet pipeline is connected to the first smelting vessel.

4. A metal smelting method using the metal smelting system according to any one of claims 1 to 3, characterized in that, Includes the following steps: Thermal storage smelting step: The metal particles to be smelted serve as the heat-absorbing working fluid, receiving and storing the radiant energy provided by the radiation source in the form of radiative heat transfer, so as to achieve temperature rise. The metal particles to be smelted, heated to a specified temperature, are initially reduced by the reducing gas supplied to the heat absorber; Sensible heat smelting step: The outlet product obtained from the heat storage smelting step is transferred to the first smelting vessel. The outlet product uses its own sensible heat as a heat source for the reduction reaction to continue, so that the metal particles to be smelted that have not been fully reduced in the outlet product can continue to be reduced.

5. The metal smelting method according to claim 4, characterized in that, The reducing gas is hydrogen. The metal particles to be smelted are one or more of the metal oxide particles of copper, manganese, iron, tungsten, molybdenum, and germanium.

6. The metal smelting method according to claim 4, characterized in that, In the thermal storage smelting step, the particle size of the metal particles to be smelted is 50-500µm.

7. The metal smelting method according to claim 4, characterized in that, The metal smelting system also includes: The first storage tank has an inlet connected to the outlet of the heat absorber, and the outlet product is diverted to the first smelting vessel and the first storage tank. A medium supply mechanism for providing gaseous heat exchange media; The inlet pipe is connected at both ends to the outlet of the medium supply mechanism and the first storage tank, respectively; Heat exchange pipelines connect the first smelting vessel and the first storage tank; The outlet pipeline is connected to the first smelting vessel; The metal smelting method further includes: Heat exchange step: The gaseous heat exchange medium provided by the medium supply mechanism is introduced into the first storage tank through the inlet pipe, and the gaseous heat exchange medium exchanges heat with the outlet product in the first storage tank; Reheating step: In the heat exchange step, the gaseous heat exchange medium after heat exchange enters the first smelting vessel through the heat exchange pipeline, and the temperature of the outlet product in the first smelting vessel increases after heat exchange with the gaseous heat exchange medium.

8. The metal smelting method according to claim 7, characterized in that, Also includes: Perform the following steps after the heat exchange process: Circulating smelting step: The outlet product after heat exchange in the first storage tank is supplied to the heat absorber for the heat storage smelting step.

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