An oxygenic process for calcium carbide production and a method thereof

Abstract

The present application relates to a kind of calcium carbide production device and production method of oxythermal method, including preheating system, fluidized bed reactor and waste heat recovery system;Preheating system includes material feeding unit, first gas-solid separation equipment, second gas-solid separation equipment, riser heater and preheating equipment;Material outlet of material feeding unit, solid material outlet of first gas-solid separation equipment, riser heater and second gas-solid separation equipment are sequentially connected;Solid material outlet of first gas-solid separation equipment and riser heater are provided with preheating equipment;Solid material outlet of second gas-solid separation equipment is connected with fluidized bed reactor.The oxythermal method calcium carbide production device provided in the present application can solve the residence time and uniform heating problem of raw material preheating under the condition of sufficient carbon source, and achieve the purpose of strong process operation flexibility and process controllability.

Description

Technical Field

[0001] This invention relates to the field of calcium carbide production and preparation, specifically to an oxygen-thermal calcium carbide production apparatus and method. Background Technology

[0002] Currently, calcium carbide (CaC2) is an important basic chemical raw material, and there are two main industrial production methods: electrothermal method and oxythermal method.

[0003] For example, WO2020087633A1 discloses a method for producing calcium carbide using an electrothermal method. The method includes the following steps: crushing semi-coke to obtain semi-coke powder; crushing quicklime to obtain quicklime powder; mixing the semi-coke powder, quicklime powder, and composite binder evenly, placing the mixture on a granulator, adding a small amount of water to moisten it, letting it stand for 45 minutes, and then pelletizing it using a disc or cylindrical pelletizer to obtain mixed pellets, which are then allowed to dry; the dried mixed pellets are then subjected to high-temperature consolidation in a reduction kiln, followed by cooling to obtain composite pellets with a size of 5-30 mm; the composite pellets are then fed into a calcium carbide furnace for calcium carbide reaction to obtain calcium carbide and calcium carbide furnace gas; the composite binder includes 5-20 parts by weight of phenolic resin, 5-20 parts by weight of liquid paraffin, and 3-12 parts by weight of wood mortar. This method can improve the production efficiency of electric furnaces and has the advantages of low energy consumption and high production capacity.

[0004] For example, CN105293497A describes an oxythermal process for smelting calcium carbide. This process is achieved with the support of a molten reactor, preheater, dryer, heat exchanger, pure oxygen equipment, and raw materials. Specifically: the preheater preheats quicklime powder to 950℃-1200℃; the dryer preheats coke powder, semi-coke powder, coal powder, or a mixture of carbon-containing powders to 200-400℃, reducing the moisture content to below 1%; the preheated raw materials are then injected into the molten reactor, where they are burned at a temperature of 1500℃-2500℃ to produce liquid calcium carbide. The liquid calcium carbide is discharged from the calcium carbide outlet of the molten reactor, and the gas generated in the molten reactor is discharged from the gas outlet at the top of the furnace. This process solves the technical problems of the oxythermal calcium carbide smelting process and achieves good environmental protection and energy-saving effects.

[0005] The oxythermal method utilizes the heat released by gasification to provide energy, which can significantly reduce energy consumption. However, heat and mass transfer in the production process are usually completed in a single reactor. Most calcium carbide furnaces have a preheating section for raw materials at the top. Since the generated high-temperature gas is not in a continuous and stable state, the residence time of the raw materials is difficult to control, resulting in insufficient heating. In addition, the simultaneous completion of heat and mass transfer makes it difficult to control the stability and controllability of the overall industrial process of the reactor.

[0006] In summary, the current oxygen-thermal process suffers from problems such as uneven preheating of reactants and low operational flexibility in its production equipment. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide an oxygen-thermal calcium carbide production apparatus and production method to solve the problems of uneven preheating of reactants and low process operation flexibility in calcium carbide production apparatus using the oxygen-thermal method.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides an oxythermal calcium carbide production apparatus, the oxythermal calcium carbide production apparatus comprising a preheating system, a fluidized bed reactor and a waste heat recovery system;

[0010] The preheating system includes a material feeding unit, a first gas-solid separation device, a second gas-solid separation device, a riser heater, and a preheating device.

[0011] The material outlet of the material feeding unit, the solid material outlet of the first gas-solid separation device, the riser heater, and the second gas-solid separation device are connected in sequence.

[0012] A preheating device is provided between the solid material outlet of the first gas-solid separation device and the riser heater;

[0013] The solid material outlet of the second gas-solid separation device is connected to the fluidized bed reactor;

[0014] In the oxythermal calcium carbide production unit, materials are transported via a carrier gas unit.

[0015] The furnace gas outlet of the fluidized bed reactor is connected to the waste heat recovery system.

[0016] The oxythermal calcium carbide production apparatus provided by this invention, under the condition of ensuring sufficient carbon source, carries out gasification in the riser heater and calcium carbide reaction in the fluidized bed reactor. That is, gasification and calcium carbide reaction are relatively independent. The high-quality energy of the high-temperature gas produced in the fluidized bed reactor can be used for preheating, which solves the problems of residence time and uniform heating of raw materials. On the other hand, electric arc-assisted heating further enhances the operability of the reactor and the controllability of the entire process.

[0017] In this invention, the preheating temperature of the raw material is adjusted by changing the air flow rate of the riser to achieve thermal balance matching with the calcium carbide reactor; the electric arc electrode of the fluidized bed reactor assists in providing the heat source for calcium carbide production.

[0018] As a preferred embodiment of the present invention, the preheating equipment includes a start-up furnace.

[0019] As a preferred embodiment of the present invention, the gas phase outlet of the first gas-solid separation device is connected to the waste heat recovery system.

[0020] Preferably, the gas phase outlet of the second gas-solid separation device is connected to the material outlet of the material feeding unit.

[0021] As a preferred embodiment of the present invention, the carrier gas unit includes a first carrier gas subunit and a second carrier gas subunit.

[0022] Preferably, the first carrier gas subunit is configured in conjunction with the material feeding unit.

[0023] Preferably, the second carrier gas subunit is configured in conjunction with the riser heater.

[0024] As a preferred technical solution of the present invention, the fluidized bed reactor includes a gas phase settling section, a fluidization section and a liquid phase section arranged sequentially according to the material flow direction.

[0025] Secondly, the present invention provides an oxythermal calcium carbide production method, wherein the oxythermal calcium carbide production method includes producing calcium carbide using the oxythermal calcium carbide production apparatus as described in the first aspect, comprising: mixing carbon material and calcium material and preheating them with carrier gas, then performing a first gas-solid separation, preheating the resulting solid material in a riser pipe, then performing a second gas-solid separation, and the resulting solid material entering a fluidized bed reactor for reaction.

[0026] As a preferred embodiment of the present invention, the carbon material includes coke powder.

[0027] Preferably, the particle size of the carbon material is ≤3mm.

[0028] Preferably, the calcium material includes quicklime.

[0029] Preferably, the particle size of the calcium material is ≤3mm.

[0030] As a preferred embodiment of the present invention, the mass ratio of carbon material to calcium material in the mixture is (2-4):1.

[0031] As a preferred embodiment of the present invention, the temperature of the preheated material is 350-450℃.

[0032] Preferably, the temperature of the material obtained by preheating the riser is 1000-1300℃.

[0033] Preferably, the mass ratio of solid to gas in the preheating of the riser is (0.6-25):1.

[0034] Preferably, the reaction includes a liquid-phase vaporization reaction.

[0035] Preferably, the temperature of the liquid-phase vaporization reaction is 2100-2400℃.

[0036] As a preferred technical solution of the present invention, the oxygen-thermal method for producing calcium carbide includes:

[0037] After the carbon and calcium materials are mixed, they are preheated by carrier gas, then undergo the first gas-solid separation. The resulting solid material is preheated by the riser, then undergoes the second gas-solid separation, and the resulting solid material enters the fluidized bed reactor for reaction.

[0038] The carbon material includes coke powder; the particle size of the carbon material is ≤3mm; the calcium material includes quicklime; the particle size of the calcium material is ≤3mm; the mass ratio of carbon material to calcium material in the mixture is (2-4):1;

[0039] The temperature of the material obtained by preheating is 350-450℃; the temperature of the material obtained by preheating through the riser is 1000-1300℃; the mass ratio of solid to gas in the riser preheating is (0.6-25):1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2100-2400℃.

[0040] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0041] The oxythermal calcium carbide production apparatus provided by this invention allows for adjustment of the raw material preheating temperature during production by controlling the amount of oxygen introduced through the riser pipe, achieving thermal balance matching with the calcium carbide reactor. For the entire production apparatus, the high-temperature byproduct gas, a high-quality heat source, can be matched with the second-stage heating of the raw materials. If ideal heat exchange with the raw materials is not possible, the waste heat can be recovered and used for heating new carrier gas or other purposes at the plant level, allowing for flexible adjustment of the heat matching. Furthermore, the electric arc can assist in stabilizing the reaction system. Therefore, this system demonstrates enhanced industrial operability and controllability. The purity of the obtained calcium carbide is ≥65.6%. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of an oxygen-thermal calcium carbide production apparatus provided in an embodiment of the present invention.

[0043] In the diagram: 1.1-Carbon silo, 1.2-Calcium silo, 2.1-First gas-solid separation equipment, 2.2-Second gas-solid separation equipment, 3-Riser heater, 4.1-Start-up furnace, 4.2-Fan, 4.3-Carrier gas preheater, 5-Fluidized bed reactor, 5.1-Arc electrode, 6-Waste heat recovery system, 7-Dust removal equipment;

[0044] I-Carrier gas, II-Fuel, III-Combustion oxidizer, IV-Oxygen, V-Calcium carbide products, VI-Solid waste, VII-Exhaust gas.

[0045] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0046] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0047] This embodiment provides an oxygen-thermal calcium carbide production apparatus, such as... Figure 1 As shown, the oxygen-thermal calcium carbide production unit includes a preheating system, a fluidized bed reactor 5, and a waste heat recovery system 6;

[0048] The preheating system includes a material feeding unit, a first gas-solid separation device 2.1, a second gas-solid separation device 2.2, a riser heater 3, and preheating equipment;

[0049] The material outlet of the material feeding unit, the solid material outlet of the first gas-solid separation device 2.1, the riser heater 3, and the second gas-solid separation device 2.2 are connected in sequence.

[0050] A preheating device is provided between the solid material outlet of the first gas-solid separation device 2.1 and the riser heater 3;

[0051] The solid material outlet of the second gas-solid separation device 2.2 is connected to the fluidized bed reactor 5;

[0052] In the oxythermal calcium carbide production unit, materials are transported via a carrier gas unit.

[0053] The gas outlet of the fluidized bed reactor 5 is connected to the waste heat recovery system 6.

[0054] The material feeding unit includes a carbon silo 1.1 and a calcium silo 1.2. The reaction raw materials in the carbon silo 1.1 and calcium silo 1.2 are transferred and heated by a carrier and then enter the first gas-solid separation device 2.1.

[0055] The first gas-solid separation device 2.1 and the second gas-solid separation device 2.2 are devices for separating the gas phase and solid phase in the conveyed material, such as cyclone separators and other commonly used gas-solid separation devices in the field.

[0056] The riser heater 3 is equipped with an oxygen supply device to supply oxygen IV, so that during the process of the raw material being raised in an oxygen atmosphere, a gasification reaction occurs, mainly carbon and oxygen react to produce carbon monoxide, and the heat released is used to heat the gas solid.

[0057] Specifically, the preheating equipment includes a starter furnace 4.1, but it can also be other equipment that can achieve the gas heating of materials as described in this invention, such as electric heating equipment, magnetic heating equipment, etc. The starter furnace 4.1 is equipped with a fan 4.2 to supply the combustion medium III, such as oxygen or air, for fuel II to burn.

[0058] The fuel II used can be gas or fuel, which is a commonly used fuel in the field for combustion in start-up furnaces.

[0059] Specifically, the gas phase outlet of the first gas-solid separation device 2.1 is connected to the waste heat recovery system 6 to further utilize the residual heat of the preheated gas.

[0060] Specifically, the gas phase outlet of the second gas-solid separation device 2.2 is connected to the material outlet of the material feeding unit; at this time, the separated high-temperature gas can preheat the initial materials such as carbon and calcium materials, so as to realize the efficient utilization of the heat energy in the device.

[0061] Specifically, the carrier gas unit includes a first carrier gas subunit and a second carrier gas subunit; the first carrier gas subunit is configured in conjunction with the material feeding unit; and the second carrier gas subunit is configured in conjunction with the riser heater 3.

[0062] In this invention, a carrier gas unit is configured to achieve both material conveying and preheating; that is, carrier gas I serves as both the medium for material conveying and the medium for material preheating. The carrier gas I used can be a combustible gas, CO, or syngas, or other commonly used carrier gases in the art. For example, in the second carrier gas subunit that works in conjunction with the riser heater 3, the carrier gas, after being heated by the carrier gas preheater, carries the solid material separated by the first gas-solid separation device 2.1 to the riser heater 3.

[0063] Specifically, the fluidized bed reactor 5 includes a gas phase settling section, a fluidization section, and a liquid phase section arranged sequentially according to the material flow direction.

[0064] In the gas-phase settling section of fluidized bed reactor 5, the preheated raw materials can be appropriately heated, and the rising high-temperature gas can reduce the dust carrying capacity through the settling section. In the fluidization section, the coke powder and quicklime solid raw materials are in a fluidized state in the rising high-temperature gas, with a longer heating time and sufficient heat transfer contact surface between the gas and solid phases. The second stage heating of the raw materials can efficiently utilize the high-quality energy of the high-temperature gas. The liquid phase section is a calcium carbide melting pool carrying powdered raw materials. Oxygen enters in a bubbling manner and comes into contact with the coke powder to undergo a gasification reaction. The high-quality gasification reaction heat source maintains the calcium carbide production temperature at 2100-2400℃, and the product flows out from the bottom of the reactor.

[0065] Furthermore, the liquid phase section of the fluidized bed reactor 5 includes an arc electrode 5.1, an oxygen inlet, and a product outlet. The upper part of the gas phase settling section includes a powdered raw material inlet connected to the solid material outlet of the second gas-solid separation device 2.2 and a high-temperature tail gas outlet connected to the waste heat recovery system 6, to ensure the temperature of the materials during the reaction process. The oxygen inlet supplies the oxygen IV required for the reaction, and the product outlet discharges the calcium carbide product V obtained during production.

[0066] In this invention, the oxygen inlet faces the bottom of the fluidized bed reactor 5 and is at an angle of 45° with the side wall. It extends downwards and enters in a bubbling shape. During the upward process, it fully contacts the coke powder to carry out a gasification reaction, generating a sufficient amount of bubbles to improve the thermal efficiency of the reactor.

[0067] Among them, the tail gas with a temperature of 1400-1700℃ discharged from the fluidized bed reactor 5 and the carrier gas from the first gas-solid separation device 2.1 can both be heat recovered through the waste heat recovery system 6 (including dust removal equipment). For example, it can be used for carrier gas preheater or plant end use. The gas with a temperature drop (less than 200℃) can be discharged externally or used as carrier gas before entering the riser or as a heat source for other processes. The generated solid waste VI can be recycled and utilized secondary according to its composition.

[0068] Furthermore, based on the above-mentioned oxythermal calcium carbide production apparatus, the present invention also provides an oxythermal calcium carbide production method, comprising: mixing carbon material and calcium material and preheating them with carrier gas, then performing a first gas-solid separation, preheating the resulting solid material in a riser pipe, then performing a second gas-solid separation, and the resulting solid material entering a fluidized bed reactor 5 for reaction.

[0069] Specifically, the carbon material includes coke powder.

[0070] Specifically, the particle size of the carbon material is ≤3mm.

[0071] Specifically, the calcium material includes quicklime.

[0072] Specifically, the particle size of the calcium material is ≤3mm.

[0073] In this invention, the particle size of the carbon material and calcium material can refer to particles of any size within a certain range. Specifically, it can be an aggregate of particles with uniform size, such as an aggregate of particles all with a size of 0.5 mm, an aggregate of particles all with a size of 0.3 mm, an aggregate of particles all with a size of 0.2 mm, an aggregate of particles all with a size of 0.3 mm, an aggregate of particles all with a size of 0.7 mm, an aggregate of particles all with a size of 3 mm, or an aggregate of particles within a certain size range, such as an aggregate of all particles with a size range of 0.5-0.8 mm, an aggregate of all particles with a size range of 0.4-0.6 mm, an aggregate of all particles with a size range of ≤3 mm, an aggregate of all particles with a size range of 0.01-0.05 mm, an aggregate of all particles with a size range of 0.04-0.08 mm, an aggregate of all particles with a size range of ≤0.5 mm, etc.

[0074] Specifically, the mass ratio of carbon material to calcium material in the mixture is (2-4):1, for example, it can be 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1 or 4:1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0075] Specifically, the temperature of the preheated material is 350-450℃, for example, it can be 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃ or 450℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0076] Specifically, the temperature of the material preheated by the riser is 1000-1300℃, for example, it can be 1000℃, 1020℃, 1060℃, 1080℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃, 1200℃, 1220℃, 1240℃, 1260℃, 1280℃ or 1300℃, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0077] Specifically, the mass ratio of solid to gas in the preheating of the riser is (0.6-25):1, for example, it can be 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, 22:1, 24:1 or 25:1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0078] Controlling the mass ratio of solids to gases in the riser helps ensure uniform preheating of the solids during the riser process, laying a good foundation for the subsequent fluidized bed reaction to ensure the reaction effect. The solids are carbon and calcium materials, and the gases include the carrier material from the solids and the introduced oxygen.

[0079] Specifically, the reaction includes a liquid-phase vaporization reaction.

[0080] Specifically, the temperature of the liquid-phase vaporization reaction is 2100-2400℃, for example, it can be 2100℃, 2120℃, 2140℃, 2160℃, 2180℃, 2200℃, 2220℃, 2240℃, 2260℃, 2280℃, 2300℃, 2320℃, 2340℃, 2360℃, 2380℃ or 2400℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0081] To further illustrate the advantages of the device provided by the present invention, the following specific implementation process is provided for description:

[0082] Example 1

[0083] This embodiment provides a process for producing calcium carbide using an oxythermal method, employing the oxythermal calcium carbide production apparatus provided by this invention, specifically including:

[0084] The material is fed into the carbon silo and calcium silo in the unit by carrier gas for preheating, and then conveyed to the first gas-solid separation device for separation. The separated solid material is then conveyed to the riser heater by the heat of the carrier gas preheater for riser preheating. Oxygen is introduced during the riser preheating process. The resulting material then enters the second gas-solid separation device for separation. The separated solid material enters the fluidized bed reactor for reaction to obtain calcium carbide product.

[0085] The gas separated by the first gas-solid separation device enters the waste heat recovery system to recover heat; the gas separated by the second gas-solid separation device is returned to the material feeding unit as a carrier gas to preheat the material.

[0086] The carbon material used is coke powder; the particle size of the carbon material is 0.5-3mm; the calcium material is quicklime; the particle size of the calcium material is 0.3-3mm; the mass ratio of carbon material to calcium material in the mixture is 2.9:1;

[0087] The temperature of the material obtained by preheating is 370°C; the temperature of the material obtained by preheating through the riser is 1080°C; the mass ratio of solid to gas in the riser preheating is 1.2:1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2200°C.

[0088] The performance indicators of the prepared calcium carbide are detailed in Table 1.

[0089] Example 2

[0090] This embodiment provides a process for producing calcium carbide using an oxythermal method, employing the oxythermal calcium carbide production apparatus provided by this invention, specifically including:

[0091] The material is fed into the carbon silo and calcium silo in the unit by carrier gas for preheating, and then conveyed to the first gas-solid separation device for separation. The separated solid material is then conveyed to the riser heater by the heat of the carrier gas preheater for riser preheating. Oxygen is introduced during the riser preheating process. The resulting material then enters the second gas-solid separation device for separation. The separated solid material enters the fluidized bed reactor for reaction to obtain calcium carbide product.

[0092] The gas separated by the first gas-solid separation device enters the waste heat recovery system to recover heat; the gas separated by the second gas-solid separation device is returned to the material feeding unit as a carrier gas to preheat the material.

[0093] The carbon material used is coke powder; the particle size of the carbon material is 0.1-0.8 mm; the calcium material is quicklime; the particle size of the calcium material is 0.2-0.6 mm; the mass ratio of carbon material to calcium material in the mixture is 2.9:1;

[0094] The temperature of the material obtained by preheating is 400℃; the temperature of the material obtained by preheating through the riser is 1240℃; the mass ratio of solid to gas in the riser preheating is 1.35:1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2300℃.

[0095] The performance indicators of the prepared calcium carbide are detailed in Table 1.

[0096] Example 3

[0097] This embodiment provides a process for producing calcium carbide using an oxythermal method, employing the oxythermal calcium carbide production apparatus provided by this invention, specifically including:

[0098] The material is fed into the carbon silo and calcium silo in the unit by carrier gas for preheating, and then conveyed to the first gas-solid separation device for separation. The separated solid material is then conveyed to the riser heater by the heat of the carrier gas preheater for riser preheating. Oxygen is introduced during the riser preheating process. The resulting material then enters the second gas-solid separation device for separation. The separated solid material enters the fluidized bed reactor for reaction to obtain calcium carbide product.

[0099] The gas separated by the first gas-solid separation device enters the waste heat recovery system to recover heat; the gas separated by the second gas-solid separation device is returned to the material feeding unit as a carrier gas to preheat the material.

[0100] The carbon material used is coke powder; the particle size of the carbon material is 0.3-3 mm; the calcium material is quicklime; the particle size of the calcium material is 0.2-0.7 mm; the mass ratio of carbon material to calcium material in the mixture is 2.9:1;

[0101] The temperature of the material obtained by preheating is 450°C; the temperature of the material obtained by preheating through the riser is 1000°C; the mass ratio of solid to gas in the riser preheating is 0.8:1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2400°C.

[0102] The performance indicators of the prepared calcium carbide are detailed in Table 1.

[0103] Example 4

[0104] This embodiment provides a process for producing calcium carbide using an oxythermal method, employing the oxythermal calcium carbide production apparatus provided by this invention, specifically including:

[0105] The material is fed into the carbon silo and calcium silo in the unit by carrier gas for preheating, and then conveyed to the first gas-solid separation device for separation. The separated solid material is then conveyed to the riser heater by the heat of the carrier gas preheater for riser preheating. Oxygen is introduced during the riser preheating process. The resulting material then enters the second gas-solid separation device for separation. The separated solid material enters the fluidized bed reactor for reaction to obtain calcium carbide product.

[0106] The gas separated by the first gas-solid separation device enters the waste heat recovery system to recover heat; the gas separated by the second gas-solid separation device is returned to the material feeding unit as a carrier gas to preheat the material.

[0107] The carbon material used is coke powder; the particle size of the carbon material is 0.2-0.53 mm; the calcium material is quicklime; the particle size of the calcium material is 0.5-3 mm; the mass ratio of carbon material to calcium material in the mixture is 2.8:1;

[0108] The temperature of the material obtained by preheating is 350°C; the temperature of the material obtained by preheating through the riser is 1300°C; the mass ratio of solid to gas in the preheating through the riser is 1.8:1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2100°C.

[0109] The performance indicators of the prepared calcium carbide are detailed in Table 1.

[0110] Table 1

[0111]

[0112]

[0113] The results of the embodiments show that the oxythermal calcium carbide production apparatus provided by the present invention, while ensuring sufficient carbon source, performs partial gasification in the riser heater, which solves the problems of residence time and uniform heating of raw materials during preheating. Furthermore, by controlling the oxygen flow rate through the riser to adjust the raw material preheating temperature, a thermal balance with the calcium carbide reactor is achieved; waste heat is recovered for heating new carrier gas or for other purposes at the plant end, and the heat matching can be flexibly adjusted; in addition, the electric arc can help maintain the stability of the reaction system; thus, the apparatus enhances the operability and controllability of the system.

[0114] The present invention is described in detail through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0115] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0116] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0117] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An oxygen-thermal calcium carbide production apparatus, characterized in that, The oxythermal calcium carbide production unit includes a preheating system, a fluidized bed reactor, and a waste heat recovery system; The preheating system includes a material feeding unit, a first gas-solid separation device, a second gas-solid separation device, a riser heater, and a preheating device. The preheating equipment includes a start-up furnace; The material outlet of the material feeding unit, the solid material outlet of the first gas-solid separation device, the riser heater, and the second gas-solid separation device are connected in sequence. A preheating device is provided between the solid material outlet of the first gas-solid separation device and the riser heater; The solid material outlet of the second gas-solid separation device is connected to the fluidized bed reactor; The gas phase outlet of the second gas-solid separation device is connected to the material outlet of the material feeding unit; The riser heater is equipped with an oxygen inlet; In the oxythermal calcium carbide production unit, materials are transported via a carrier gas unit. The furnace gas outlet of the fluidized bed reactor is connected to the waste heat recovery system; The carrier gas unit includes a first carrier gas subunit and a second carrier gas subunit; The first carrier gas subunit is configured in conjunction with the material feeding unit; The second carrier gas subunit is equipped with a riser heater; The fluidized bed reactor comprises a gas-phase settling section, a fluidization section, and a liquid-phase section arranged sequentially according to the material flow direction.

2. The oxygen-thermal calcium carbide production apparatus as described in claim 1, characterized in that, The gas phase outlet of the first gas-solid separation device is connected to the waste heat recovery system.

3. A method for producing calcium carbide using an oxythermal process, characterized in that, The oxygen-thermal calcium carbide production method includes the production of calcium carbide using the oxygen-thermal calcium carbide production apparatus as described in claim 1, comprising: mixing carbon material and calcium material and preheating them with carrier gas, then performing a first gas-solid separation, preheating the resulting solid material in a riser pipe, then performing a second gas-solid separation, and the resulting solid material entering a fluidized bed reactor for heating and reaction.

4. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The carbon material includes coke powder.

5. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The particle size of the carbon material is ≤3mm.

6. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The calcium material includes quicklime.

7. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The particle size of the calcium material is ≤3mm.

8. The oxygen-thermal calcium carbide production method as described in claim 4, characterized in that, The mass ratio of carbon material to calcium material in the mixture is (2-4):

1.

9. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The carrier gas includes combustible gas.

10. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The temperature of the material obtained by preheating with carrier gas is 350-450℃.

11. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The temperature of the material obtained by preheating the riser is 1000-1300℃.

12. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The mass ratio of solid to gas in the preheating of the riser is (0.6-25):

1.

13. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The reaction includes a liquid-phase vaporization reaction.

14. The oxygen-thermal calcium carbide production method as described in claim 13, characterized in that, The temperature of the liquid-phase vaporization reaction is 2100-2400℃.

15. The oxygen-thermal calcium carbide production method as described in claim 3, characterized in that, The gas obtained from the first gas-solid separation and the reaction enters the waste heat recovery system for waste heat recovery.

16. The oxygen-thermal calcium carbide production method as described in claim 15, characterized in that, The temperature of the obtained gas is 1400-1700℃.

17. The oxygen-thermal calcium carbide production method as described in claim 15, characterized in that, The temperature of the exhaust gas after waste heat recovery is <200℃.

18. The oxygen-thermal calcium carbide production method as described in claim 15, characterized in that, The heat obtained from the waste heat recovery is used for carrier gas heating.

19. The oxygen-thermal method for producing calcium carbide as described in any one of claims 3-18, characterized in that, The oxygen-thermal calcium carbide production method includes: After the carbon and calcium materials are mixed, they are preheated by carrier gas, then undergo the first gas-solid separation. The resulting solid material is preheated by the riser, then undergoes the second gas-solid separation, and the resulting solid material enters the fluidized bed reactor for reaction. The carbon material includes coke powder; the particle size of the carbon material is ≤3mm; the calcium material includes quicklime; the particle size of the calcium material is ≤3mm; the mass ratio of carbon material to calcium material in the mixture is (2-4):1; The temperature of the material obtained by preheating is 350-450℃; the temperature of the material obtained by preheating through the riser is 1000-1300℃; the mass ratio of solid to gas in the riser preheating is (0.6-25):1; the reaction includes a liquid-phase gasification reaction; the temperature of the liquid-phase gasification reaction is 2100-2400℃.

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