Metal smelting system and metal smelting method

Abstract

The invention provides a metal smelting system and a metal smelting method.The method comprises the following steps that heat storage smelting is conducted, specifically, metal particles to be smelted serve as heat absorption working media, and radiation energy provided by a radiation source is received and stored in a radiation heat transfer mode so as to achieve temperature rising; to-be-smelted metal particles heated to the specified temperature are preliminarily reduced by reducing gas supplied into the heat absorber; and a sensible heat smelting step, specifically, the outlet product obtained in the heat storage smelting step is transferred to a first smelting container, sensible heat of the outlet product serves as a heat source for continuous generation of the reduction reaction, and the to-be-smelted metal particles which are not fully reduced in the outlet product continue to be reduced. According to the invention, the consumption of the reducing gas is reduced, the power consumption of metal smelting is reduced, full contact and reduction of metal particles to be smelted and the reducing gas are facilitated, and the reduction rate of metal smelting is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal smelting, and in particular to a metal smelting system and a metal smelting method. Background Art

[0002] The low-carbon greening of the steel industry is an urgent task at present and also the future development direction. At present, foreign steel enterprises have taken the hydrogen direct reduction-electric furnace short process as an innovative technology for zero carbon emissions. The hydrogen vertical furnace direct reduction process is the focus of hydrogen metallurgy research and development at home and abroad. To maintain the reduction reaction of iron ore in the vertical furnace, an external heat source needs to be provided. Using hydrogen as a heat carrier and heat transfer medium is the main solution at present. However, due to the small density and specific heat capacity of hydrogen, excessive high-temperature hydrogen needs to be introduced to supply energy to maintain the reaction, which leads to the problems of large hydrogen circulation volume and power consumption in the vertical furnace. At the same time, when the heat-carrying hydrogen contacts the pelletized iron ore flowing in the reverse direction in the vertical furnace, the outermost iron oxide of the pelletized iron ore is quickly reduced by the high-temperature hydrogen. At this time, the layered iron element generated in the outer layer of the pellet is prone to sintering, forming a dense spherical shell barrier layer, which limits the diffusion of hydrogen to the center of the sphere and further reduction reaction, resulting in low iron reduction rate and low hydrogen utilization rate. In addition, solar energy also has problems such as fluctuating energy supply, making it difficult to stably and continuously supply energy to the reaction. Summary of the invention

[0003] In response to the above problems, the present invention provides a metal smelting system and a metal smelting method, which reduce the amount of reducing gas used, reduce the power consumption of metal smelting, and facilitate the full contact and reduction of the metal particles to be smelted with the reducing gas, thereby improving the reduction rate of metal smelting.

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

[0005] A radiation source for providing radiation energy required for reducing metal particles to be smelted;

[0006] A reducing gas-based supply mechanism for providing reducing gas required for reducing metal particles to be smelted;

[0007] The heat absorber is connected to the outlet of the reducing gas-based supply mechanism. The heat absorber is used to provide a heat absorption and smelting place for the metal particles to be smelted. The metal particles to be smelted serve as a heat absorbing medium and receive and store the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve temperature increase. The metal particles to be smelted that have been heated to a specified temperature are initially reduced by the reducing gas.

[0008] The inlet of the first smelting container is connected to the outlet of the heat absorber. The outlet product of the heat absorber enters the first smelting container. The outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product 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 short and consumes less energy.

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

[0011] The metal particles to be smelted have high thermal energy as an endothermic medium and also serve as a heat carrier. Therefore, the reducing gas provided by the reducing gas-based supply mechanism does not need to carry a large amount of thermal energy, and thus does not need to rely on a large amount of circulating gas to transport the heat required for reduction, which reduces the number of gas cycles and gas usage, and reduces the cycle power consumption. In addition, the endothermic process of the endothermic medium causes the temperature of the endothermic medium to rise by a certain amount and react with hydrogen at a relatively slow rate, rather than the prior art where the reducing gas is quickly reduced by high-temperature hydrogen when it comes into contact with the pelletized iron ore. Therefore, it is possible to avoid the formation of an obstacle layer on the surface of the metal particles to be smelted, thereby ensuring the ability of the reducing gas to diffuse to the center of the metal particles and further reduce them.

[0012] After the metal particles to be smelted are heated to a specified temperature as an endothermic working medium, a reduction reaction can occur directly, which shortens the smelting time and simplifies the smelting process.

[0013] Furthermore, by setting up the first smelting container, the export product can be transferred without continuously occupying the heat absorber, so that the metal particles to be smelted that have not been completely reduced can continue to be reduced in the first smelting container under the action of sensible heat, thereby overcoming the problem of mismatch between heat storage and reduction reaction time, improving the material turnover efficiency and smelting efficiency, and realizing the utilization of sensible heat, which is conducive to energy saving.

[0014] In addition, compared with other heat storage media, the metal particles to be smelted have a larger heat storage capacity and a higher heat storage temperature as an endothermic working fluid. When the radiation energy is fluctuating radiation energy (such as sunlight) and the radiation energy fluctuates greatly, the metal particles to be smelted are used for heat storage, and the temperature of the metal particles will not change drastically due to the fluctuation of the radiation energy. The fluctuating radiation energy is converted into the thermal energy of the metal particles, the volatility of the radiation energy is absorbed, and the transformation from unstable energy to stable thermal energy is realized, so that the smelting process can also be carried out under relatively stable temperature conditions, ensuring the temperature stability and smelting efficiency of the metal particles, which is conducive to improving the reduction rate. The reduction reaction of the metal particles is an endothermic process, which can balance the temperature fluctuations of the metal particles when absorbing fluctuating radiation energy for heat storage to a certain extent, ensuring the temperature stability of the metal particles. When the radiation energy is non-fluctuating radiation energy, the metal particles can uniformly absorb the radiation energy, store heat and be reduced, ensuring the quality of smelting and helping to improve the reduction rate.

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

[0016] According to the technical solution, the energy flux density of the radiation energy is controlled to ensure that the heating rate of the metal particles to be smelted is not lower than the heat absorption rate of the metal particles to be smelted when they are reduced, so that the temperature of the metal particles to be smelted is always not lower than the temperature required for the reduction reaction, thereby ensuring that the reduction reaction proceeds continuously and improving the smelting efficiency.

[0017] In the optional technical solution of the present invention, the outlet of the reducing gas-based supply mechanism is arranged corresponding to the outlet of the heat absorber, and the reducing gas-based supply mechanism includes: a flow regulating valve for regulating the outlet flow of the reducing gas; a flow detector connected to the flow regulating valve, the flow detector is configured to detect the flow of the reducing gas and control the opening of the flow regulating valve according to the flow of the reducing gas.

[0018] According to the technical solution, the reducing gas at the outlet of the reducing gas-based supply mechanism enters through the outlet of the heat absorber, and can form a counterflow with the metal particles to be smelted, which is conducive to increasing the contact area between the reducing gas and the metal particles to be smelted, and promoting full reduction. Furthermore, by controlling the flow rate of the reducing gas in real time, the rate of the reduction reaction in the heat absorber can be controlled, and the volatility of the radiation energy can be effectively balanced. And the flow rate of the reducing gas can be matched with the flow rate of the metal particles to be smelted, reducing the amount of reducing gas used and improving the utilization rate of the reducing gas.

[0019] In the optional technical solution of the present invention, the heat absorber is a fluidized bed solid particle heat absorber, a solid particle free fall heat absorber, an inclined sliding particle heat absorber or a curtain particle heat absorber.

[0020] According to the technical solution, the existing fluidized bed solid particle heat absorber, solid particle free-fall heat absorber, inclined sliding particle heat absorber or curtain particle heat absorber on the market can be used as the heat absorber, so that the metal smelting system is easy to process and manufacture, and the convenience of the operation method of the metal smelting system is improved. Preferably, the metal particles to be smelted in the heat absorber are fluidized, thereby increasing the disturbance of the metal particles to be smelted, improving the uniformity of the absorption of radiation energy by the metal particles to be smelted, thereby facilitating the temperature uniformity of the metal particles to be smelted and facilitating the occurrence of the reduction reaction.

[0021] In an optional technical solution of the present invention, the metal smelting system further comprises:

[0022] a first storage tank, the inlet of which is connected to the outlet of the heat absorber, and the outlet product is divided into the first smelting container and the first storage tank;

[0023] A medium supply mechanism, used for providing gas heat exchange medium;

[0024] An inlet pipeline, both ends of which are respectively connected to the outlet of the medium supply mechanism and the first storage tank;

[0025] A heat exchange pipeline connecting the first smelting container and the first storage tank;

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

[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 its temperature rises after heat exchange 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 reduction of the product in the first smelting container, which is beneficial to improve the reduction rate of the metal particles in the first smelting container.

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

[0029] Heat storage smelting step: the metal particles to be smelted act as a heat absorbing medium, receiving and storing the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve temperature increase; the metal particles to be smelted heated to a specified temperature are supplied to the reducing gas in the heat absorber for preliminary reduction;

[0030] Sensible heat smelting step: the outlet product obtained in the heat storage smelting step is transferred to the first smelting container, and the outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product continue to be reduced.

[0031] According to the technical solution, a high-temperature heat source is provided for metal smelting in the form of radiation heat transfer. Compared with other new energy gas-based metallurgy, such as photovoltaic metallurgy, which requires the conversion of light energy into electrical energy for metallurgy, the process is short, the energy supply is stable, and there are fewer energy conversion processes, which reduces heat loss. The metal particles to be smelted can directly undergo a reduction reaction after absorbing heat to a specified temperature as an endothermic working fluid, which shortens the smelting time and simplifies the smelting process. And the metal particles to be smelted absorb radiation energy as an endothermic working fluid and convert it into thermal energy and serve as a heat carrier (loaded with the heat required for reduction), so there is no need to use a large amount of circulating gas to transport the heat required for smelting, which reduces the number of gas cycles, reduces the cycle power consumption, and is conducive to promoting the occurrence of reduction reactions and improving the reduction rate. In addition, by transferring the product and utilizing the sensible heat of the outlet product to continue to reduce the metal particles to be smelted, the problem of mismatch between heat storage and reduction reaction time is overcome, and the turnover efficiency of materials and smelting efficiency are improved.

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

[0033] The reducing gas is hydrogen;

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

[0035] According to the technical solution, the use of hydrogen for metal smelting can reduce carbon emissions; when hydrogen is used as a reducing agent to reduce the above metal oxide particles, it will not only absorb a large amount of heat, but also produce an equal amount of water vapor per mole of hydrogen. By adjusting the hydrogen intake speed / flow rate, the proportion of hydrogen and water vapor in the reaction atmosphere can be controlled to achieve the rate of hydrogen reduction of iron in the reaction chamber and the amount of heat absorbed by the reaction, so as to achieve the purpose of matching the fluctuating radiation energy and maintaining the temperature stability in the heat absorber. Metal oxide particles of copper, manganese, iron, tungsten, molybdenum, germanium, etc. have a better reception rate for radiation energy. The received radiation energy is converted into high-temperature heat energy and used as the heat energy required for the reduction reaction, which makes it easier to meet the heat energy requirements of the reduction reaction.

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

[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, thereby improving the reduction reaction efficiency, that is, improving the efficiency of metal smelting.

[0038] In an optional technical solution of the present invention, the metal smelting system further comprises:

[0039] a first storage tank, the inlet of which is connected to the outlet of the heat absorber, and the outlet product is divided into the first smelting container and the first storage tank;

[0040] A medium supply mechanism, used for providing gas heat exchange medium;

[0041] An inlet pipeline, both ends of which are respectively connected to the outlet of the medium supply mechanism and the first storage tank;

[0042] A heat exchange pipeline connecting the first smelting container and the first storage tank;

[0043] An outlet pipeline is connected to the first smelting container;

[0044] Metal smelting methods also include:

[0045] Heat exchange step: passing the gas heat exchange medium provided by the medium supply mechanism into the first storage tank through the inlet pipeline, and the gas heat exchange medium exchanges heat with the outlet product in the first storage tank;

[0046] Heat supplementation step: the gas heat exchange medium after heat exchange in the heat exchange step enters the first smelting container through the heat exchange pipeline, and the outlet product in the first smelting container is heated up after heat exchange with the gas heat exchange medium after heat exchange.

[0047] According to the technical scheme, the gas heat exchange medium is heated by exchanging heat with a part of the outlet product generated by the diversion, and the heated gas heat exchange medium is introduced into the first smelting container to provide the heat required for reduction, which is beneficial 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] The optional technical solution of the present invention further includes: performing after the heat exchange step:

[0049] Circulation smelting step: the outlet product after heat exchange in the first storage tank is supplied to the heat absorber for heat storage smelting step.

[0050] According to the technical solution, by executing the cyclic smelting step, the export product that is not fully reduced can be further reduced, thereby improving the reduction rate of metal smelting. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0052] Figure 2 It is a schematic flow chart of the metal smelting method in the first embodiment of the present invention.

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

[0054] Reference numerals:

[0055] Radiation source 1; reducing gas-based supply mechanism 2; flow regulating valve 21; heat absorber 3; feed inlet 31; discharge port 32; bottom wall 33; material guide slope 331; radiation energy inlet 34; first smelting container 4; air inlet pipeline 41; air outlet pipeline 42; feed silo 5; first storage tank 6; inlet pipeline 71; heat exchange pipeline 72; outlet pipeline 73. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[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-based 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-based 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-based supply mechanism 2, and the heat absorber is used to provide a heat absorption and smelting place for the metal particles to be smelted. The heat absorber 3 contains the metal particles to be smelted, and the metal particles to be smelted also serve as a heat absorbing medium, receiving and storing the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve heating; the metal particles to be smelted that are heated to a specified temperature are initially reduced by the reducing gas; the specified temperature is the temperature at which the metal particles to be smelted react with the reducing gas to undergo a reduction reaction. The inlet of the first smelting container 4 is connected to the outlet of the heat absorber 3, and the outlet product of the heat absorber 3 enters the first smelting container 4. The outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product continue to be reduced.

[0058] In this embodiment, a high-temperature heat source is provided for metal smelting by means of 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 short and consumes less energy.

[0059] The metal particles to be smelted serve as both the working fluid to be smelted and the heat absorbing working fluid in the heat absorber 3. They absorb radiant heat in the heat absorber 3 and convert it into thermal energy. At the same time, a reduction reaction occurs in the heat absorber 3, so that the heat absorption and smelting of the metal particles to be smelted occur in the same container, which simplifies the structure of the metal smelting system and shortens the metal smelting process.

[0060] The metal particles to be smelted have high thermal energy as an endothermic medium and also serve as a heat carrier. Therefore, the reducing gas provided by the reducing gas-based supply mechanism does not need to carry a large amount of thermal energy, and thus does not need to rely on a large amount of circulating gas to transport the heat required for reduction, which reduces the number of gas cycles and gas usage, and reduces the cycle power consumption. In addition, the endothermic process of the endothermic medium causes the temperature of the endothermic medium to rise by a certain amount and react with hydrogen at a relatively slow rate, rather than the prior art where the reducing gas is quickly reduced by high-temperature hydrogen when it comes into contact with the pelletized iron ore. Therefore, it is possible to avoid the formation of an obstacle layer on the surface of the metal particles to be smelted, thereby ensuring the ability of the reducing gas to diffuse to the center of the metal particles and further reduce them.

[0061] After the metal particles to be smelted are heated to a specified temperature as an endothermic working medium, a reduction reaction can occur directly, which shortens the smelting time and simplifies the smelting process.

[0062] Furthermore, by setting up the first smelting container 4, the outlet product is transferred without continuously occupying the heat absorber 3, so that the metal particles to be smelted that have not been completely reduced can continue to be reduced in the first smelting container 4 under the action of sensible heat, thereby overcoming the problem of mismatch between heat storage and reduction reaction time (for example, it takes 40 minutes for the iron ore heat-absorbing particles to heat up to 1000°C, while it takes 90 minutes for it to be completely reduced. After the iron ore heat-absorbing particles are transferred, they can continue to react using sensible heat, thereby improving the reduction efficiency), thereby improving the material turnover efficiency and smelting efficiency, and realizing the utilization of sensible heat, which is beneficial to energy saving.

[0063] In addition, compared with other heat storage media, the metal particles to be smelted have a larger heat storage capacity and a higher heat storage temperature as an endothermic working fluid. When the radiation energy is fluctuating radiation energy (such as sunlight) and the radiation energy fluctuates greatly, the metal particles to be smelted are used for heat storage, and the temperature of the metal particles will not change drastically due to the fluctuation of the radiation energy. The fluctuating radiation energy is converted into the thermal energy of the metal particles, the volatility of the radiation energy is absorbed, and the transformation from unstable energy to stable thermal energy is realized, so that the smelting process can also be carried out under relatively stable temperature conditions, ensuring the temperature stability and smelting efficiency of the metal particles, which is conducive to improving the reduction rate. The reduction reaction of the metal particles is an endothermic process, which can balance the temperature fluctuations of the metal particles when absorbing fluctuating radiation energy for heat storage to a certain extent, ensuring the temperature stability of the metal particles. When the radiation energy is non-fluctuating radiation energy, the metal particles can uniformly absorb the radiation energy, store heat and be reduced, ensuring the quality of smelting and helping to improve the reduction rate.

[0064] In a preferred embodiment of the present invention, the radiation source 1 is capable of emitting radiation energy with a high energy flux density. The metal particles to be smelted receive the radiation energy with a high energy flux density to increase the heat transfer temperature difference inside the particles, strengthen the heat transfer process, and promote the efficient reduction of the metal particles to be smelted.

[0065] Specifically, the main forms of radiation energy provided by the radiation source 1 include light radiation and / or heat radiation. Taking light radiation as an example, the radiation source 1 includes sunlight and / or a focusing simulation lamp. When the radiation source 1 is sunlight, the sunlight is radiated to the surface of the metal particles to be smelted, which increases the temperature of the metal particles, improves the utilization rate of solar energy, and saves smelting costs. Furthermore, a focusing device (not shown in the figure) can also be provided to focus the sunlight to the radiation energy inlet 34 of the absorber 3 to improve the light receiving efficiency and the heat absorption efficiency of the heat absorbing medium.

[0066] When sunlight is insufficient, a spotlight simulation lamp can be used to emit light, thereby improving the applicability of the metal smelting system. Specifically, the spotlight simulation lamp comprises a plurality of xenon lamps (such as 14) and a simulation lamp controller, which is used to emit incident energy flux to the heat absorber 3. The spotlight simulation lamp can adjust the focal length and pointing point to ensure that the incident energy flux emitted is in the optimal incident energy flux position, thereby improving the heat absorption efficiency and heat absorption temperature of the heat absorbing medium. The present invention does not limit the specific setting form of the spotlight simulation lamp, and technicians can adjust it according to actual needs. In addition to the spotlight simulation lamp and sunlight, a high-temperature radiation source, other visible light radiation sources, electromagnetic microwaves and other non-visible light electromagnetic radiation sources or particle radiation sources can also be provided to provide radiation energy with high energy flux density, and 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 when the metal particles to be smelted are reduced. By controlling the energy flux density of the radiation energy, it is ensured 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, so that 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 is carried out continuously and improving the smelting efficiency. Preferably, the energy flux density of the radiation energy is 79-95KW / m 2. By controlling the energy flux density of the radiation energy within a suitable range, the heating rate and heating temperature of the metal particles to be smelted can be guaranteed, so that the heating rate is higher than the heat absorption rate of the reduction reaction, and the heating temperature reaches a temperature not lower than the temperature required for the reduction reaction within a specified time, thereby ensuring the reduction reaction and improving the smelting efficiency. It should be noted that technicians can adjust the energy flux density of the 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 control method of the energy flux density. For example, when the radiation source 1 is sunlight, the energy flux density is adjusted by changing the angle of the solar concentrator. When the 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 detector (not shown in the figure), the flow regulating valve 21 is used to adjust the outlet flow of the reducing gas, the flow detector is connected to the flow regulating valve 21, and the flow detector is configured to detect the flow of the reducing gas and control the opening of the flow regulating valve 21 according to the flow of the reducing gas. By controlling the flow of the reducing gas in real time, the rate of the reduction reaction in the absorber can be controlled, and the volatility of the radiation energy can be effectively balanced. And the flow of the reducing gas can be matched with the flow rate of the metal particles to be smelted, so that the metal particles to be smelted and the reducing gas react fully, 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 solid particle free-fall heat absorber, an inclined sliding particle heat absorber, or a curtain particle heat absorber. By using the heat absorption cavity of the existing fluidized bed solid particle heat absorber, the solid particle free-fall heat absorber, the inclined sliding particle heat absorber, or the curtain particle heat absorber on the market as the heat absorber 3, the metal smelting system is easy to process and manufacture, and the convenience of metal smelting is improved.

[0070] Specifically, Figure 1 As shown, the absorber 3 is a solid particle free-fall type absorber. An inlet 31 is provided at the upper end of the absorber 3, and an outlet 32 ​​is provided at the lower end of the absorber 3. The bottom wall 33 of the absorber 3 has a guide slope 331 for guiding the mixture to slide down, and a radiation energy inlet 34 is provided on the side wall of the absorber 3 opposite to the guide slope 331. The outlet of the reducing gas-based supply mechanism 2 is arranged corresponding to the outlet 32 ​​of the absorber 3, and the reducing gas supplied by the reducing gas-based supply mechanism 2 flows in a countercurrent direction with the metal particles to be smelted, so that the metal particles to be smelted are fully mixed with the reducing gas, the reaction area is increased, and the reaction efficiency is improved.

[0071] In this embodiment, the heat absorber 3 provides a place where the radiation energy is converted into heat energy and the reduction reaction occurs simultaneously. The heat absorber 3 has a simple structure and is easy to implement, which is beneficial to saving operating costs. It also simplifies the smelting system structure, shortens the smelting process flow, and improves smelting efficiency.

[0072] Furthermore, the setting of the guide slope 331 enables the mixture to be initially smelted in a flowing manner under the action of gravity, thereby improving the efficiency and uniformity of the mixture in receiving radiation energy, and is conducive to improving the reduction rate. Specifically, the radiation energy with high energy flux density heats the surface layer of the spherical metal particles, and the surface layer and local areas are heated to undergo a reduction reaction. As the metal particles roll, other local areas are gradually heated by radiation and then undergo a reduction reaction, ensuring that the iron ore particles have a high reduction rate. In some embodiments, the mixture is not limited to being transported by the heat absorber 3 having the guide slope 331, and other mechanisms that can transport the granular mixture in a fluidized form are also applicable to this embodiment, and the present application does not limit this.

[0073] Optionally, by controlling the inclination angle of the guide slope 331 and the length of the guide slope 331, the flow rate and residence time of the material in the heat absorber 3 can be controlled, so that the metal particles to be smelted can be fully smelted in the heat absorber 3. Preferably, the temperature of the product at the outlet of the heat absorber 3 should be in a reasonable temperature range to ensure that after the product is transferred from the heat 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 discharge port 32 to ensure that the material in the heat absorber 3 can be uniformly and preliminarily reduced to improve the smelting efficiency. The technician can adjust the setting position of the discharge port 32 and the opening of the discharge port 32 according to the actual situation, and this embodiment does not limit this.

[0074] The setting of the radiation energy inlet 34 is conducive to the passage of radiation energy such as light, thereby improving the heating efficiency of the mixture; in addition, the gas generated during the reduction reaction can also be discharged through the radiation energy inlet 34. In some embodiments, the radiation energy inlet 34 may not be set as an open structure, such as being set as a transparent cover plate with a hole structure, which can also allow the passage of radiation energy such as light and the discharge of gas.

[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 the present embodiment, the product at the outlet of the heat absorber 3 specifically includes a mixture of metal particles to be smelted, metal elements and reducing agent particles.

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

[0078] In an optional embodiment, the number of the first smelting container 4 is multiple, and the inlets of the multiple first smelting containers 4 can be arranged corresponding to the outlet of the heat absorber 3. Multiple first smelting containers 4 can be used alternately. When the product fills one of the first smelting containers 4, another first smelting container 4 is moved to the discharge port 32 of the heat absorber 3 to receive the outlet product. Preferably, the metal smelting system also includes an air inlet pipeline 41 and an air outlet pipeline 42, and the air inlet pipeline and the air outlet pipeline 42 are respectively connected to the first smelting container 4, and the reducing gas is supplied to the first smelting container 4 through the air inlet pipeline 41, and the reducing gas required for the reduction of the metal particles to be smelted in the first smelting container 4 is supplemented, which is conducive to promoting the reduction rate. Similarly, a flow regulating valve can also be set on the air inlet pipeline 41 to adjust the flow of the reducing gas. In some embodiments, the reducing gas-based supply mechanism 2 can supply reducing gas to the first smelting container 4 and the heat absorber 2 at the same time, or it can supply reducing gas to the first smelting container 4 and the heat absorber 2 separately, and this application is not limited to this.

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

[0080] Heat storage smelting step: the metal particles to be smelted serve as a heat absorbing medium, receiving and storing the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve temperature increase; the metal particles to be smelted heated to a specified temperature are supplied to the reducing gas in the heat absorber 3 for preliminary reduction; the specified temperature is the temperature at which the metal particles to be smelted react with the reducing gas to undergo a reduction reaction;

[0081] Sensible heat smelting step: the outlet product obtained in the heat storage smelting step is transferred to the first smelting container 4, and the outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product continue to be reduced.

[0082] In this embodiment, a high-temperature heat source is provided for metal smelting in the form of radiation heat transfer. Compared with other new energy gas-based metallurgy, such as photovoltaic metallurgy, which requires the conversion of light energy into electrical energy for metallurgy, the process is short, the energy supply is stable, and there are fewer energy conversion processes, which reduces heat loss. The metal particles to be smelted can directly undergo a reduction reaction after absorbing heat to a specified temperature as an endothermic working fluid, which shortens the smelting time and simplifies the smelting process. And the metal particles to be smelted absorb radiation energy as an endothermic working fluid and convert it into thermal energy and serve as a heat carrier (loaded with the heat required for reduction), so there is no need to use a large amount of circulating gas to transport the heat required for smelting, which reduces the number of gas cycles, reduces the cycle power consumption, and is conducive to promoting the occurrence of reduction reactions and improving the reduction rate. In addition, by transferring the product and utilizing the sensible heat of the outlet product to continue to reduce the metal particles to be smelted, the problem of mismatch between heat storage and reduction reaction time is overcome, and the turnover efficiency of materials and smelting efficiency are improved.

[0083] In this embodiment, the metal particles to be smelted enter the heat absorber 3 from the feed bin 5, and the discharge port 32 of the heat absorber 3 is always in an open state. Since the guide slope 331 is an inclined structure, the metal particles to be smelted on the guide slope 331 can be initially reduced in a dynamic form on the guide slope 331 under the action of the gravity component, and the products moved to the discharge port 32 of the heat absorber 3 can be continuously discharged. The dynamic metal particles are conducive to fully contacting with the radiation source to heat up and fully contacting with the reducing gas to be reduced, 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 above metal oxide particles, it will not only absorb a large amount of heat, but also produce an equal amount of water vapor per mole of hydrogen. By adjusting the intake speed / flow rate of hydrogen, the proportion of hydrogen and water vapor in the reaction atmosphere can be controlled, and the rate of hydrogen reduction of iron in the reaction chamber and the amount of heat absorbed by the reaction can be adjusted to achieve the purpose of matching the fluctuating radiation energy and maintaining the temperature stability in the heat absorber.

[0085] In a preferred embodiment of the present invention, the metal particles to be smelted are one or more metal oxide particles of copper, manganese, iron, tungsten, molybdenum, and germanium. The metal oxide particles of copper, manganese, iron, tungsten, molybdenum, germanium, etc. have a darker color and a higher absorption rate for the radiation source 1 (such as light in the visible wavelength range of sunlight). For example, iron ore particles (Fe 2 O 3 , Fe 3 O 4, FeO) has an absorption rate of nearly 90% for light in the visible wavelength range of solar energy, and can be directly used as a heat absorbing medium. Furthermore, the heating rate of iron ore particles can reach 27.6K / min under the irradiation of sunlight. The heating rate of iron ore particles is higher than the reaction rate of iron ore particles and reducing gas, and the heat supply is higher than the reaction endothermicity, which can ensure that the reaction is carried out continuously and efficiently.

[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 a good absorption rate to the radiation source 1 are also suitable for smelting by the metal smelting method provided by the present invention. In this embodiment, the metal particles to be smelted can be obtained by crushing and screening the ore to be smelted, but it is certainly not limited to this.

[0087] In a preferred embodiment of the present invention, the particle size of the metal particles to be smelted is 50-500μm. 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 to 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, 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 70-100μm. It should be noted that technicians 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 filled with the product, the first smelting container 4 is removed, and the spare first smelting container 4 is moved to a position corresponding to the outlet of the heat absorber 3 to continue to receive the product at the outlet of the heat absorber 3. The alternating use of multiple first smelting containers 4 is conducive to ensuring the continuous smelting.

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

[0090] The thickness and flow rate of the metal particles to be smelted at the inlet of the heat absorber 3 are controlled by controlling the opening of the electric gate valve at the outlet of the feed bin 5, so as to ensure that the metal particles to be smelted absorb heat fully and evenly.

[0091] Control the opening of the electric gate valve at the outlet of the heat absorber 3 to adjust the residence time and flow rate of the metal particles to be smelted in the heat absorber 3 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 embodiment of the present invention are described above. The smelting method is described below by taking the case where the metal particles are iron ore particles and the reducing agent is reducing gas as an example.

[0093] The metal particles to be smelted can be heated to 600-1000°C 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 bin 5. Due to gravity, the iron ore particles flow into the absorber 3 from the outlet of the feed bin 5. The radiation source 1 emits high-power concentrated incident energy to flow into the absorber 3. The iron ore particles in the absorber 3 receive the heat source and can reach a heating rate of 27.6K / min, 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 serve as an endothermic heat storage medium. After receiving the radiation source 1, the temperature can reach a high temperature of about 950°C, which meets the reduction reaction temperature of the iron ore particles, that is, a reduction reaction occurs with the reducing gas in the absorber 3.

[0094] Furthermore, the outlet temperature of the iron ore particles can be as high as about 950°C. 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. The main component of the iron ore particles is Fe 2 O 3 , because Fe 2 O 3 The specific heat capacity at 1000℃ is 0.88KJ / (kg·℃), Fe 2 O 3 A temperature drop of 400℃ releases 352kJ / kg of heat. The heat released meets the heat required for the reaction, which can ensure that the iron ore particles further react with the reducing gas continuously and efficiently, ensuring that the iron ore particles have a high reduction rate.

[0095] Furthermore, after the first smelting container 4 is filled with completely reacted iron ore particles, all of them can be poured out, and then the spare first smelting container 4 will take over for use, and the spare first smelting container 4 will continue to receive the products flowing out of the heat absorber 3. The alternating use of multiple first smelting containers 4 can realize the smelting cycle operation.

[0096] [Second embodiment]

[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 of the first embodiment. The parts not specially explained, including the figure marks and text descriptions, are the same as the first embodiment and will not be repeated here.

[0098] In the third embodiment of the present invention, the metal smelting system also includes: a first storage tank 6, a medium supply mechanism (not shown in the figure), an inlet pipeline 71, a heat exchange pipeline 72 and an outlet pipeline 73, the inlet of the first storage tank 6 is connected to the discharge port 32 of the heat absorber 3; the medium supply mechanism is used to provide heat exchange medium, and the two ends of the inlet pipeline 71 are respectively connected to the outlet of the medium supply mechanism and the first storage tank 6; the heat exchange pipeline 72 connects the first smelting container 4 and the first storage tank 6; the outlet pipeline 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 the temperature rises after heat exchange 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 reduction of the product in the first smelting container 4, which is beneficial to improve the reduction rate of the metal particles to be smelted in the first smelting container 4. In the embodiment of the present invention, the gas heat exchange medium is H 2 , H 2 The heat of the high-temperature particles in the first storage tank 6 is absorbed to increase the temperature, and the heat required for the reduction of the metal particles to be smelted in the first smelting container 4 is supplemented, and H 2 It can also participate in the reduction reaction as a reducing agent to ensure the normal progress of the reduction reaction, which is beneficial to improve the reduction rate.

[0100] Correspondingly, this embodiment provides a metal smelting method, and the parts not specially explained, including the figure marks 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 gas heat exchange medium H into the first storage tank 6 through the inlet pipeline 71; 2 The gas heat exchange medium in the first storage tank 6 is heated by the sensible heat released by the high-temperature product, and the heated gas heat exchange medium enters the first smelting container 4 through the heat exchange pipeline 72. The metal particles to be smelted in the first smelting container 4 are supplemented with heat from the gas heat exchange medium in the heat exchange pipeline 72 and the reducing agent, so that the metal particles to be smelted can continue to undergo a reduction reaction, thereby improving the reduction rate of the metal particles to be smelted. Furthermore, the metal particles to be smelted after being cooled in the first storage tank 6 can be added back into the silo 5 to achieve re-smelting of the metal particles to be smelted and improve the reduction rate.

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

[0103] Heat exchange step: passing the gas heat exchange medium provided by the medium supply mechanism into the first storage tank 6 through the inlet pipeline 71, and the gas heat exchange medium exchanges heat with the outlet product in the first storage tank 6;

[0104] Supplementary heat step: the gaseous heat exchange medium after heat exchange in the heat exchange step enters the first smelting container 4 through the heat exchange pipeline 72, and the outlet product in the first smelting container 4 is heated up after heat exchange with the gaseous heat exchange medium after heat exchange.

[0105] In a preferred embodiment of the present invention, the metal smelting method further comprises: performing a circulation smelting step after the heat exchange step: supplying the outlet product after heat exchange in the first storage tank 6 to the heat absorber 3 for a heat storage smelting step. By performing the circulation smelting step, the outlet product that is not fully reduced can be further reduced, thereby improving the reduction rate of metal smelting.

[0106] The above are only 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 in the protection scope of the present invention.

Claims

1. A metal smelting system, characterized in that: include: A radiation source for providing radiation energy required for reducing metal particles to be smelted; A reducing gas-based supply mechanism, used for providing reducing gas required for reducing the metal particles to be smelted; A heat absorber is connected to the outlet of the reducing gas-based supply mechanism, and is used to provide a heat absorption and smelting place for the metal particles to be smelted. The metal particles to be smelted serve as a heat absorbing medium, and receive and store the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve temperature increase; The metal particles to be smelted are heated to a specified temperature and are initially reduced by the reducing gas; The inlet of the first smelting container is connected to the outlet of the heat absorber, and the outlet product of the heat absorber enters the first smelting container. The outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product continue to be reduced.

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

3. The metal smelting system according to claim 2, characterized in that: The outlet of the reducing gas-based supply mechanism is arranged corresponding to the outlet of the heat absorber, and the reducing gas-based supply mechanism comprises: A flow regulating valve, used to adjust the outlet flow of the reducing gas; A flow detector is connected to the flow regulating valve, and the flow detector is configured to detect the flow of the reducing gas and control the opening of the flow regulating valve according to the flow of the reducing gas.

4. The metal smelting system according to claim 1, characterized in that: The heat absorber is a fluidized bed solid particle heat absorber, a solid particle free-falling heat absorber, an inclined sliding particle heat absorber or a curtain particle heat absorber.

5. The metal smelting system according to claim 1, characterized in that: The metal smelting system also includes: a first storage tank, the inlet of which is connected to the outlet of the heat absorber, and the outlet product is divided into the first smelting container and the first storage tank; A medium supply mechanism, used for providing gas heat exchange medium; An inlet pipeline, two ends of which are respectively connected to the outlet of the medium supply mechanism and the first storage tank; a heat exchange pipeline, connecting the first smelting container and the first storage tank; An outlet pipeline is connected to the first smelting container.

6. A metal smelting method using the metal smelting system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Heat storage smelting step: the metal particles to be smelted serve as a heat absorbing medium, receiving and storing the radiation energy provided by the radiation source in the form of radiation heat transfer to achieve temperature increase; The metal particles to be smelted, which are heated to a specified temperature, are initially reduced by the reducing gas supplied into the heat absorber; Sensible heat smelting step: the outlet product obtained in the heat storage smelting step is transferred to the first smelting container, and the outlet product uses its own sensible heat as a heat source for the continued reduction reaction, so that the metal particles to be smelted that have not been fully reduced in the outlet product continue to be reduced.

7. The metal smelting method according to claim 6, characterized in that: The reducing gas is hydrogen; The metal particles to be smelted are one or more metal oxide particles of copper, manganese, iron, tungsten, molybdenum, and germanium.

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

9. The metal smelting method according to claim 6, characterized in that: The metal smelting system also includes: a first storage tank, the inlet of which is connected to the outlet of the heat absorber, and the outlet product is divided into the first smelting container and the first storage tank; A medium supply mechanism, used for providing gas heat exchange medium; An inlet pipeline, two ends of which are respectively connected to the outlet of the medium supply mechanism and the first storage tank; a heat exchange pipeline, connecting the first smelting container and the first storage tank; an outlet pipeline, connected to the first smelting container; The metal smelting method further comprises: Heat exchange step: passing the gas heat exchange medium provided by the medium supply mechanism into the first storage tank through the inlet pipeline, and the gas heat exchange medium exchanges heat with the outlet product in the first storage tank; Supplementary heat step: the gas heat exchange medium after heat exchange in the heat exchange step enters the first smelting container through the heat exchange pipeline, and the temperature of the outlet product in the first smelting container increases after heat exchange with the gas heat exchange medium after heat exchange.

10. The metal smelting method according to claim 9, characterized in that: Also includes: After the heat exchange step, perform: Circulation smelting step: supplying the outlet product after heat exchange in the first storage tank to the heat absorber to perform the heat storage smelting step.

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