Method for producing yellow phosphorus

Abstract

The invention relates to a method for producing yellow phosphorus, belongs to the field of phosphorus chemical industry production, and solves the problems of high reaction temperature, high unit product energy consumption and slag yield, high production cost, unstable quality and heavy environmental pollution in the existing yellow phosphorus production. The method comprises the following steps: respectively and finely grinding phosphorite and a siliceous reducing agent to obtain phosphorite powder and siliceous reducing agent powder, mixing the phosphorite powder and the siliceous reducing agent powder according to a certain ratio, uniformly mixing through a uniform mixing machine, and carrying out cold pressing into blocks to obtain composite blocks; screening the composite block masses, arranging the screened composite block masses meeting the requirements on a trolley through a distributing machine, feeding the trolley into a yellow phosphorus extraction kiln, and heating and preserving heat in an electromagnetic wave heating manner according to a certain heating system to obtain phosphorus steam and solid slag; the phosphorus steam is recycled through a phosphorus recycling system, yellow phosphorus is obtained after condensation and rinsing, and solid slag is cooled to the specified temperature along with the furnace and discharged through a discharging machine. The method for producing yellow phosphorus is low in energy consumption and slag yield, low in production cost and environment-friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphorus chemical production, and in particular to a method for producing yellow phosphorus. Background Art

[0002] Yellow phosphorus is an extremely important basic industrial raw material with extremely wide applications, and currently still mainly focuses on related products.

[0003] The traditional process for extracting yellow phosphorus is to mix phosphate rock, coke, and silica stone, and add them together into an electric furnace. The electric furnace converts electrical energy into heat energy to enable a smelting reduction reaction to occur. The reduced phosphorus vapor and soot escape and are obtained as yellow phosphorus products through processes such as condensation and rinsing. The high-temperature slag is directly discharged from the electric furnace.

[0004] There are some drawbacks in the production of yellow phosphorus by the traditional electric furnace method: (1) Using carbon as a reducing agent, the reaction process is an endothermic reaction with a reaction temperature of about 1450°C. The reaction temperature is relatively high. Due to the use of raw material carbon, a desulfurization device needs to be equipped later, resulting in high costs; (2) The phosphorus vapor mainly contains CO gas, and is accompanied by SO2 and dust, making it prone to explosions, fires, poisoning, etc.; the purity of the phosphorus vapor is low, and some muddy phosphorus will be generated during the condensation process, requiring secondary extraction later; (3) The reaction process is a melting reaction, and a large amount of slag needs to be heated to the molten state, increasing production energy consumption and generating a large amount of phosphorus-containing waste slag. The phosphorus-containing waste slag is a waste containing various harmful elements and pollutes the environment; (4) During the production process, electrode heating is used, and the materials are prone to uneven heating and local crusting, resulting in unstable yellow phosphorus quality; after long-term use, condensed metaphosphoric acid will form around the electrode holes, easily causing poor insulation and locking the electrode; a highly corrosive and difficult-to-clean phosphorus-containing layer will form on the inner wall of the furnace cavity; (5) The mechanization and intelligentization levels of producing yellow phosphorus by the electric furnace method are relatively low, with high energy consumption, large resource waste, low production efficiency, serious environmental pollution, and high safety risks, which do not meet the current development requirements of low carbon, energy conservation, environmental protection, and safety. Therefore, there is an urgent need for a new method for producing yellow phosphorus to solve the many drawbacks existing in the prior art. Summary of the Invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a method for producing yellow phosphorus to at least solve one of the following problems existing in the existing yellow phosphorus production methods: 1. High reaction temperature, high unit product energy consumption and slag production, and high production cost; 2. Unstable yellow phosphorus quality; 3. Serious environmental pollution.

[0006] The object of the present invention is mainly achieved through the following technical solutions:

[0007] The present invention provides a method for producing yellow phosphorus, including the following steps:

[0008] S1: Grind the phosphate minerals and silica-based reducing agents separately to obtain phosphate ore powder and silica-based reducing agent powder. Mix the phosphate ore powder and silica-based reducing agent powder according to a certain ratio, homogenize them through a homogenizer, and then cold press them into blocks to obtain composite agglomerates.

[0009] S2: Screen the composite agglomerates, arrange the qualified composite agglomerates after screening on the trolley through a distributing machine, and enter the yellow phosphorus extraction kiln. Heat them up and keep them warm according to a certain heating system by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag.

[0010] S3: Recover the phosphorus vapor through a phosphorus recovery system, and obtain yellow phosphorus after condensation and rinsing. The solid slag is cooled in the furnace to a specified temperature and unloaded through a discharging machine.

[0011] Further, in step S1, the phosphate minerals are phosphate ores, the P2O5 content in the phosphate ores is 25% - 35%, and the particle size of the phosphate ores is ≤20 mm.

[0012] Further, in step S1, the silica-based reducing agent is one or more of industrial silicon, silicon micropowder, or other silica-based reducing agents;

[0013] For the industrial silicon, the silicon content is ≥99%; for the silicon micropowder, the silicon content is 90% - 93%, and for the other silica-based reducing agents, the silicon content is ≥80%.

[0014] Further, in step S1, the fineness of the phosphate ore powder and silica-based reducing agent powder is 100 - 200 mesh;

[0015] The ratio of the phosphate ore powder to the silica-based reducing agent powder is 100∶12 - 20.

[0016] Further, in step S2, the electromagnetic wave heating is realized through an electromagnetic wave heating furnace device;

[0017] The electromagnetic wave heating furnace device includes an electromagnetic wave generator, a bi-directional coupler, a water-containing load circulator, a straight or curved waveguide, a power distributor, a three-screw tuner, a water-cooled energy feeding port, a continuous electromagnetic wave heating furnace, a power supply control system, a propulsion trolley with a propulsion device, wave-trapping materials, an electromagnetic wave penetration layer, a heat-insulating layer, and an electromagnetic wave suppression layer.

[0018] Further, in step S2, the particle size of the composite agglomerates is 30 mm * 50 mm - 50 mm * 80 mm.

[0019] Further, in step S2, the electromagnetic wave heating temperature is 1100°C - 1150°C, and the heat preservation time is 1 - 4 h.

[0020] Further, in step S2, the electromagnetic wave heating power is 300 - 400 kW.

[0021] Further, in step S3, the specified temperature ≤ 40°C.

[0022] Further, in step S3, the phosphorus content of the solid slag ≤ 1%.

[0023] A heating device for producing yellow phosphorus, used for the above method of producing yellow phosphorus, includes an electromagnetic wave generator, a bi-directional coupler, a water-containing load circulator, a straight or curved waveguide, a power distributor, a three-screw tuner, a water-cooled energy feeding port, a continuous electromagnetic wave heating furnace, a power supply control system, a propulsion trolley with a propulsion device, wave guiding material, an electromagnetic wave penetration layer, a heat preservation layer, and an electromagnetic wave suppression layer.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] 1. The method of the present invention uses electromagnetic wave heating for yellow phosphorus extraction, with high thermal efficiency. The extraction temperature is 1100°C - 1150°C. Compared with the traditional method, the extraction temperature is reduced by 200 - 300°C, and the energy consumption is reduced by more than 40%. The working conditions of workers are greatly improved.

[0026] 2. The method of the present invention selects silica as the reducing agent, which can avoid using coke as the reducing agent, meets the current requirements of low-carbon development, promotes low-carbon emission reduction and green development; the volume of phosphorus furnace gas is small, no CO gas is generated, the content of S dust impurities is small, and the purity of phosphorus vapor is high (purity > 99%), which is easy to recover, and it is energy-saving, safe, and environmentally friendly.

[0027] 3. During the silicon thermal reduction reaction process of the method of the present invention, the reaction product SiO2 can combine with CaO in the original phosphorus mineral to promote the reaction process. For every 1 ton of yellow phosphorus extracted, the slag production is about 5 - 6 tons. Compared with the slag production of the existing method, the slag production is reduced by more than 30%. At the same time, the phosphorus content in the slag is low (< 1%) and it is still in a solid state, which can be directly used in industries such as building materials and municipal engineering.

[0028] 4. The method of the present invention uses electromagnetic wave heating for extraction. During the heating process, the composite agglomerates are heated evenly, the process time is short, there is no crusting phenomenon, and the obtained yellow phosphorus has high and stable quality.

[0029] 5. The method of the present invention is heated in a static environment, with almost no dust pollution and a small amount of flue gas, only a few hundredths of that of the traditional process. The yellow phosphorus recovery cost is low; the new technology has no wastewater and noise pollution, and has the characteristics of low-carbon, environmental protection, and safety.

[0030] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the following description, and some advantages can be made obvious from the description, or can be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the description and the drawings. Description of the Drawings

[0031] The drawings are only for the purpose of showing specific embodiments, and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs denote the same components.

[0032] Figure 1 It is a process flow chart for the method of producing yellow phosphorus according to the present invention;

[0033] Figure 2 It is a schematic structural diagram of the electromagnetic wave heating furnace device according to Embodiment 5 of the present invention;

[0034] Figure 3 It is an internal structure diagram of the electromagnetic wave heating furnace device according to Embodiment 5 of the present invention.

[0035] Reference Signs:

[0036] 1 - Electromagnetic wave generator; 2 - Bi - directional coupler; 3 - Water - containing load circulator; 4 - Straight or curved waveguide; 5 - Power distributor; 6 - Three - screw tuner; 7 - Water - cooled energy feeding port; 8 - Continuous electromagnetic wave heating furnace; 9 - Power supply control system; 10 - Propulsion trolley with propulsion device; 11 - Wave - inducing material; 12 - Electromagnetic wave penetration layer; 13 - Heat - insulating layer; 14 - Electromagnetic wave suppression layer; 15 - Temperature detection device; 16 - Pressure detection device; 17 - Controller; 18 - Temperature sensor; 19 - Power regulator; 20 - Electromagnetic wave generator start / stop device. Detailed Embodiments

[0037] The following will specifically describe the preferred embodiments of the present invention with reference to the drawings. The drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, and are not used to limit the scope of the present invention.

[0038] The present invention provides a method for producing yellow phosphorus, comprising the following steps:

[0039] S1: Grind the phosphorus ore and the siliceous reducing agent separately to obtain phosphorus ore powder and siliceous reducing agent powder. Mix the phosphorus ore powder and the siliceous reducing agent powder according to a certain ratio, then mix them evenly by a mixer, and then cold - press them into blocks to obtain composite agglomerates;

[0040] S2: Screen the composite agglomerates, arrange the qualified composite agglomerates after screening onto the trolley through a distributing machine, and then put them into the yellow phosphorus extraction kiln. Heat them up and keep them warm according to a certain heating regime by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag.

[0041] S3: Recover the phosphorus vapor through a phosphorus recovery system, and obtain yellow phosphorus after condensation and rinsing. The solid slag is cooled in the furnace to a specified temperature and then discharged through a discharging machine.

[0042] Specifically, in step S1, the phosphorus mineral is phosphate rock, the P2O5 content in the phosphate rock is 25% - 35%, and the particle size of the phosphate rock is ≤ 20 mm; the siliceous reducing agent is one or more of industrial silicon, silica fume or other siliceous reducing agents. Among them, the silicon content of industrial silicon is ≥ 99%; the silicon content of silica fume is 90% - 93%; the silicon content of other siliceous reducing agents is ≥ 80%. Grind the phosphate rock and the siliceous reducing agent to 100 - 200 mesh respectively through a mill. The ratio of phosphate rock powder to siliceous reducing agent is 100∶12 - 20. The mixing time of the mixer is 30 - 60 min. Add 8% - 18% of the moisture of the mixture weight of the phosphate rock powder and the siliceous reducing agent, and send it into a briquetting machine. Set the pressure to 100 - 150 t to carry out cold briquetting for forming to obtain composite agglomerates.

[0043] Specifically, in step S2, screen the composite agglomerates, and screen out the composite agglomerates with a particle size of 30 mm * 50 mm - 50 mm * 80 mm. Arrange them onto N trolleys through a distributing machine. The trolleys with the arranged materials are successively sent into the feeding transfer car every 4 - 15 min through a stepping device. Transfer the trolleys on the feeding transfer car into the yellow phosphorus extraction kiln. Replace the air in the extraction kiln with nitrogen for 5 - 8 min. After preheating the composite agglomerates to 800 - 1000 °C, then reduce the composite agglomerates by means of electromagnetic wave heating. The electromagnetic wave power is 300 - 400 kw. Reduce the composite agglomerates by electromagnetic wave heating until the temperature rises to 1100 °C - 1150 °C and keep it warm for 1 - 4 h to make the phosphorus vapor escape.

[0044] After the composite agglomerates are cooled to below 200 °C, replace the air in the yellow phosphorus extraction kiln with nitrogen again for 5 - 8 min. Then transfer the trolley into the discharging transfer car, transfer the trolley into the rotary track through the discharging transfer car, and discharge the solid slag that has been reduced and cooled to below 40 °C through a discharging machine. Then, through the distributing machine for batching, send the feeding transfer car into the yellow phosphorus extraction kiln through the stepping device, and so on in a cyclic manner.

[0045] Specifically, the electromagnetic wave heating is achieved through an electromagnetic wave heating furnace device, which includes an electromagnetic wave generator, a double directional coupler, a water-containing load circulator, a straight or curved waveguide, a power distributor, a three-screw tuner, a water-cooled energy feeding port, a continuous electromagnetic wave heating furnace, a power supply control system, a propulsion trolley with a propulsion device, a wave guiding material, an electromagnetic wave penetration layer, a heat preservation layer, and an electromagnetic wave suppression layer;

[0046] The electromagnetic wave generator enters the water-cooled energy feeding port through a straight or curved waveguide and is input into the continuous electromagnetic wave heating furnace from the top; the power distributor adjusts the power distribution through a three-screw tuner; the wave guiding material is provided on the upper side of the propulsion trolley with a propulsion device; the power supply control system is arranged on the top of the base; the electromagnetic wave generator, the water-containing load circulator, the straight or curved waveguide, the power distributor, the water-cooled energy feeding port, and the top of the continuous electromagnetic wave heating furnace are all connected by bolts.

[0047] Preferably, the electromagnetic wave generator is divided into two paths through the power distributor via a straight or curved waveguide and enters the water-cooled energy feeding port and is input into the continuous electromagnetic wave heating furnace from the top.

[0048] An electromagnetic wave penetration layer and a heat preservation layer are arranged inside the electromagnetic wave heating furnace; the electromagnetic wave penetration layer is arranged at the top of the electromagnetic wave heating furnace, and the heat preservation layer is arranged on the side wall of the electromagnetic wave heating furnace; an electromagnetic wave suppression layer is arranged on the outer wall of the electromagnetic wave heating furnace.

[0049] Multiple groups of temperature detection devices and pressure detection devices are arranged inside the electromagnetic wave heating furnace; the temperature detection devices and the pressure detection devices are arranged inside the heat preservation layer, and the temperature detection devices and the pressure detection devices are interlocked with the power supply control system.

[0050] The power supply control system includes a controller, a temperature sensor, a power regulator, and an electromagnetic wave generator start / stop device. The controller, the temperature sensor, the power regulator, and the electromagnetic wave generator start / stop device are arranged on the power supply control system, and the controller, the temperature sensor, the power regulator, and the electromagnetic wave generator start / stop device are correspondingly connected to each other through wires. [[ID=X]] [[ID=Y]]

[0051] Specifically, in step S3, the phosphorus vapor is recovered through a phosphorus recovery system, enters the phosphorus collection tank after being sprayed and condensed by a multi-stage cooling tower, and the yellow phosphorus discharged from the phosphorus collection tank is obtained after being repeatedly rinsed with hot water or steam. The solid slag is cooled to a specified temperature (≤40°C) with the furnace and unloaded by a discharging machine; the residual phosphorus content in the solid slag is less than 1%.

[0052] It should be noted that the present invention uses the silicon thermal reduction method to produce yellow phosphorus, and the main reduction chemical reactions of phosphate rock and silicon-based reducing agent are as follows:

[0053] 2(3CaO·2PO4)+5Si=2P2↑+6CaO·5SiO2

[0054] In the above chemical reaction, the Gibbs free energy is always negative, and the reaction can proceed spontaneously.

[0055] In the present invention, silica is selected as the reducing agent, which can avoid using coke as the reducing agent. The volume of phosphorus furnace gas is small, no CO gas is generated, the content of S-containing dust impurities is small, and the purity of phosphorus vapor is high (>99%), which is easy to recover. The electromagnetic wave heating method is adopted for yellow phosphorus extraction, with high thermal efficiency. The extraction temperature is 1100°C - 1200°C, which is 200 - 300°C lower than that of the traditional method, and the energy consumption is reduced by more than 40%. The reaction product SiO2 of yellow phosphorus extraction in the present invention can combine with CaO in the original mineral to promote the reaction process. For every 1 ton of yellow phosphorus extracted, the slag production is about 5 - 6 tons. Compared with the slag production of the existing method, the slag production is reduced by more than 30%. At the same time, the phosphorus content in the slag is low (<1%) and it is still in a solid state, which can be directly used in industries such as building materials and municipal engineering.

[0056] Example 1

[0057] Yellow phosphorus is produced in this example through the following steps:

[0058] S1: The phosphorus mineral and the silica reducing agent are respectively finely ground to obtain phosphate rock powder and silica reducing agent powder. The phosphate rock powder and the silica reducing agent powder are mixed according to a certain ratio, then mixed evenly by a mixer, and then cold-pressed into blocks to obtain composite briquettes.

[0059] Among them, the phosphorus mineral is phosphate rock, the P2O5 content in the phosphate rock is 32%, and the particle size of the phosphate rock is about 20 mm;

[0060] The silica reducing agent is industrial silicon, and the silicon content is 99%;

[0061] The phosphate rock and the silica reducing agent are respectively finely ground to 100 mesh by a mill. The ratio of the phosphate rock powder to the silica reducing agent is 100∶16, that is, the input amounts of the phosphate rock powder and the industrial silicon are respectively: 100 kg of phosphate rock powder and 16 kg of industrial silicon;

[0062] The mixing time of the mixer is 30 min, 8% of the moisture of the weight of the mixture of the phosphate rock powder and the silica reducing agent is added, and it is sent into a briquetting machine for cold pressing and briquetting. The pressure is 100 t to obtain composite briquettes.

[0063] S2: The composite briquettes are screened, and the qualified composite briquettes after screening are arranged on the trolley through a distributing machine and enter the yellow phosphorus extraction kiln. They are heated to 1100 - 1150°C by the electromagnetic wave heating method and kept warm to obtain phosphorus vapor and solid slag;

[0064] Screen the composite agglomerates, and select the composite agglomerates with a particle size of 30mm*50mm - 50mm*80mm. Arrange them on N trolleys through a distributing machine. The trolleys with the materials are successively sent into the feeding transfer car every 4 minutes through a stepping device. Then transfer the trolleys on the feeding transfer car into the yellow phosphorus extraction kiln. Replace the air in the extraction kiln with nitrogen for 5 minutes. After preheating the composite agglomerates to 800°C, reduce the composite agglomerates by using the electromagnetic wave heating method. The electromagnetic wave power is 300kw. Reduce the composite agglomerates by electromagnetic wave heating until the temperature rises to 1100°C and keep it at this temperature for 1h to allow the phosphorus vapor to escape;

[0065] After the composite agglomerates are cooled to below 200°C, replace the air in the yellow phosphorus extraction kiln with nitrogen again for 5 minutes. Then transfer the trolleys into the discharging transfer car, transfer the trolleys into the rotary track through the discharging transfer car, and discharge the solid slag cooled to below 40°C after reduction through a discharging machine. Then, after distributing the materials through a distributing machine, send the feeding transfer car into the yellow phosphorus extraction kiln through a stepping device, and repeat this cycle.

[0066] S3: Recover the phosphorus vapor through a phosphorus recovery system. After spraying and condensing it in multiple cooling towers, it enters the phosphorus collection tank. The yellow phosphorus discharged from the phosphorus collection tank is repeatedly rinsed with hot water or steam and then condensed and rinsed to obtain yellow phosphorus. The solid slag is cooled in the furnace to 38°C and discharged through a discharging machine.

[0067] After analysis, the residual phosphorus content in the solid slag is 0.63%, the yellow phosphorus energy consumption is 8300 kwh / t of product, the phosphorus ore raw material required is 7.6 t / t of product, the slag amount generated is 5.7 t / t of product, and the purity of the primary yellow phosphorus is 99.5%.

[0068] Example 2

[0069] Yellow phosphorus is produced in this example through the following steps:

[0070] S1: Grind the phosphorus mineral and the siliceous reducing agent separately to obtain phosphorus ore powder and siliceous reducing agent powder. Mix the phosphorus ore powder and the siliceous reducing agent powder according to a certain ratio and mix them evenly through a mixer, and then cold-press them into blocks to obtain composite agglomerates;

[0071] Among them, the phosphorus mineral is phosphorus ore, the P2O5 content in the phosphorus ore is 32%, and the particle size of the phosphorus ore is about 18mm;

[0072] The siliceous reducing agent is industrial silicon, and the silicon content is 99%;

[0073] Grind the phosphorus ore and the siliceous reducing agent to 200 meshes respectively through a mill. The ratio of the phosphorus ore powder to the siliceous reducing agent is 100∶20, that is, the input amounts of the phosphorus ore powder and the industrial silicon are: 100 kg of phosphorus ore powder and 20 kg of industrial silicon;

[0074] The mixing time of the mixer is 30 min. 8% of the weight of the mixture of phosphate rock powder and siliceous reducing agent is added with water, and it is sent into a briquetting machine for cold briquetting. The pressure is 100 t to obtain composite briquettes.

[0075] S2: Screen the composite briquettes, arrange the qualified composite briquettes after screening on the trolley through a distributing machine, and put them into the yellow phosphorus extraction kiln. Heat up and keep warm according to a certain heating system by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag;

[0076] Screen the composite briquettes, and screen out the composite briquettes with a particle size of 30 mm * 50 mm - 50 mm * 80 mm. Arrange them on N trolleys through a distributing machine. The loaded trolleys are successively sent into the feeding ferry car every 4 min through a stepping device. Transfer the trolleys on the feeding ferry car into the yellow phosphorus extraction kiln. Nitrogen is used for replacement in the extraction kiln for 5 min. After preheating the composite briquettes to 900 °C, then reduce the composite briquettes by means of electromagnetic wave heating. The electromagnetic wave power is 360 kw. Reduce the composite briquettes by electromagnetic wave heating. When the temperature rises to 1100 °C, keep warm for 1 h to make the phosphorus vapor escape;

[0077] After the composite briquettes are cooled to below 200 °C, the yellow phosphorus extraction kiln is replaced with nitrogen again for 5 min. Then transfer the trolley into the discharging ferry car, transfer the trolley into the rotary track through the discharging ferry car, and unload the solid slag cooled to below 40 °C after reduction through a discharging machine. Then, after distributing through a distributing machine, send the feeding ferry car into the yellow phosphorus extraction kiln through a stepping device, and so on in a cycle.

[0078] S3: The phosphorus vapor is recovered through a phosphorus recovery system, enters the phosphorus collection tank after being sprayed and condensed by a multi-stage cooling tower. The yellow phosphorus discharged from the phosphorus collection tank is repeatedly rinsed with hot water or steam and then condensed and rinsed to obtain yellow phosphorus. The solid slag is cooled with the furnace to 38 °C and unloaded through a discharging machine.

[0079] After analysis, the residual phosphorus content in the solid slag is 0.31%, the yellow phosphorus energy consumption is 8400 kwh / t of product, 7.7 t / t of product of phosphate rock raw material is required, the slag production is 5.5 t / t of product, and the purity of primary yellow phosphorus is 99.6%.

[0080] Example 3

[0081] Yellow phosphorus is produced in the following steps in this example:

[0082] S1: Grind the phosphate minerals and siliceous reducing agents separately to obtain phosphate rock powder and siliceous reducing agent powder. Mix the phosphate rock powder and siliceous reducing agent powder according to a certain ratio, mix them evenly through a mixer, and then form blocks by cold pressing to obtain composite briquettes;

[0083] Among them, the phosphorus mineral is phosphate rock, the P2O5 content in the phosphate rock is 32%, and the particle size of the phosphate rock is about 20 mm;

[0084] The silica-based reducing agent is silica fume, and the silicon content is 91%;

[0085] The phosphate rock and the silica-based reducing agent are respectively finely ground to 100 mesh by a mill, and the ratio of the phosphate rock powder to the silica-based reducing agent is 100∶16, that is, the input amounts of the phosphate rock powder and industrial silicon are respectively: 100 kg of phosphate rock powder and 16 kg of silica fume;

[0086] The mixing time of the mixer is 60 min, 18% of the moisture of the total weight of the mixture of the phosphate rock powder and the silica-based reducing agent is added, and it is sent into a briquetting machine for cold briquetting. The pressure is 150 t to obtain a composite briquette.

[0087] S2: Screen the composite briquettes, arrange the qualified composite briquettes after screening on the trolley through a distributing machine, enter the yellow phosphorus extraction kiln, and heat up and keep warm according to a certain heating system by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag;

[0088] Screen the composite briquettes, and screen out the composite briquettes with a particle size of 30 mm * 50 mm - 50 mm * 80 mm. Arrange them on N trolleys through a distributing machine. The trolleys with the material arranged are successively sent into the feeding ferry car every 4 min through a stepping device. Transfer the trolleys on the feeding ferry car into the yellow phosphorus extraction kiln. The inside of the extraction kiln is replaced with nitrogen for 8 min. After preheating the composite briquettes to 1000 °C, then reduce the composite briquettes by means of electromagnetic wave heating. The electromagnetic wave power is 320 kw. Reduce the composite briquettes by electromagnetic wave heating, raise the temperature to 1150 °C, and keep warm for 4 h to make the phosphorus vapor escape;

[0089] After the composite briquettes are cooled to below 200 °C, replace the yellow phosphorus extraction kiln with nitrogen again for 8 min. Then transfer the trolley into the discharging ferry car, transfer the trolley into the rotary track through the discharging ferry car, and discharge the solid slag cooled to below 40 °C after reduction through a discharging machine. After re-distributing through a distributing machine, send the feeding ferry car into the yellow phosphorus extraction kiln through a stepping device, and so on in a cycle.

[0090] S3: The phosphorus vapor is recovered through a phosphorus recovery system, enters the phosphorus collection tank after being sprayed and condensed by a multi-stage cooling tower, and the yellow phosphorus discharged from the phosphorus collection tank is repeatedly rinsed with hot water or steam and then condensed and rinsed to obtain yellow phosphorus. The solid slag is cooled with the furnace to 35 °C and discharged through a discharging machine.

[0091] After analysis, the residual phosphorus content in the solid slag is 0.72%, the yellow phosphorus energy consumption is 8700 kwh / t of product, 7.8 t / t of product of phosphate rock raw material is required, the slag amount generated is 5.9 t / t of product, and the purity of primary yellow phosphorus is 99.4%.

[0092] Example 4

[0093] Yellow phosphorus is produced in this example through the following steps:

[0094] S1: Grind the phosphate mineral and the siliceous reducing agent separately to obtain phosphate ore powder and siliceous reducing agent powder. Mix the phosphate ore powder and the siliceous reducing agent powder according to a certain ratio, then mix them evenly through a mixer, and then cold press them into blocks to obtain composite agglomerates;

[0095] Among them, the phosphate mineral is phosphate rock, the P2O5 content in the phosphate rock is 32%, and the particle size of the phosphate rock is about 19 mm;

[0096] The siliceous reducing agent is silica fume, and the silicon content is 91%;

[0097] Grind the phosphate rock and the siliceous reducing agent separately to 100 mesh through a mill. The ratio of the phosphate ore powder to the siliceous reducing agent is 100:18, that is, the input amounts of the phosphate ore powder and industrial silicon are: 100 kg of phosphate ore powder and 18 kg of silica fume;

[0098] The mixing time of the mixer is 50 min. Add 18% of the weight of the mixture of the phosphate ore powder and the siliceous reducing agent as water, and send it into a briquetting machine for cold pressing and briquetting. The pressure is 150 t to obtain composite agglomerates.

[0099] S2: Screen the composite agglomerates, arrange the qualified composite agglomerates after screening on the trolley through a distributing machine, enter the yellow phosphorus extraction kiln, and heat up and keep warm according to a certain heating system by using electromagnetic wave heating to obtain phosphorus vapor and solid slag;

[0100] Screen the composite agglomerates, screen out the composite agglomerates with a particle size of 30 mm * 50 mm - 50 mm * 80 mm, arrange them on N trolleys through a distributing machine, and the loaded trolleys are sent into the feeding transfer car through a stepping device at intervals of 4 min in turn. Transfer the trolleys on the feeding transfer car into the yellow phosphorus extraction kiln. The inside of the extraction kiln is replaced with nitrogen for 6 min. After preheating the composite agglomerates to 1000 °C, then use electromagnetic wave heating to reduce the composite agglomerates. The electromagnetic wave power is 400 kw. Reduce the composite agglomerates by electromagnetic wave heating, raise the temperature to 1150 °C, and keep warm for 3 h to make the phosphorus vapor escape;

[0101] After the composite agglomerates are cooled to below 200 °C, replace the yellow phosphorus extraction kiln with nitrogen for 6 min again. Then transfer the trolley into the discharging transfer car, transfer the trolley into the rotary track through the discharging transfer car, and unload the solid slag cooled to below 40 °C after reduction through a discharging machine. Then, after distributing through a distributing machine, send the feeding transfer car into the yellow phosphorus extraction kiln through a stepping device, and cycle in this way.

[0102] S3: The phosphorus vapor is recovered through a phosphorus recovery system. After being sprayed and condensed in a multi-stage cooling tower, it enters the phosphorus collection tank. The yellow phosphorus discharged from the phosphorus collection tank is repeatedly rinsed with hot water or steam and then condensed and rinsed to obtain yellow phosphorus. The solid slag is cooled with the furnace to 35°C and discharged through a discharger.

[0103] After analysis, the residual phosphorus content in the solid slag is 0.52%, the energy consumption of yellow phosphorus is 8700 kwh / t of product, the phosphorus ore raw material required is 7.5 t / t of product, the slag amount generated is 5.7 t / t of product, and the purity of primary yellow phosphorus is 99.7%.

[0104] Comparative Example 1

[0105] Yellow phosphorus is produced in this comparative example through the following steps:

[0106] S1: The phosphorus mineral and the siliceous reducing agent are respectively finely ground to obtain phosphorus ore powder and siliceous reducing agent powder. The phosphorus ore powder and the siliceous reducing agent powder are mixed according to a certain ratio and then homogenized by a homogenizer, and then cold-pressed into blocks to obtain composite agglomerates;

[0107] Among them, the phosphorus mineral is phosphorus ore, the P2O5 content in the phosphorus ore is 32%, and the particle size of the phosphorus ore is about 19 mm;

[0108] The siliceous reducing agent is silica powder, and the silicon content is 91%;

[0109] The phosphorus ore and the siliceous reducing agent are respectively finely ground to 100 mesh by a mill. The ratio of the phosphorus ore powder to the siliceous reducing agent is 100∶18, that is, the input amounts of the phosphorus ore powder and industrial silicon are respectively: 100 kg of phosphorus ore powder and 18 kg of silica powder;

[0110] The homogenizing time of the homogenizer is 50 min, 20% of the moisture of the weight of the mixture of the phosphorus ore powder and the siliceous reducing agent is added, and it is sent into a briquetting machine for cold pressing and briquetting. The pressure is 150 t to obtain composite agglomerates.

[0111] S2: The composite agglomerates are screened, and the qualified composite agglomerates after screening are arranged on the trolley through a distributing machine and enter the yellow phosphorus extraction kiln. They are heated and kept warm according to a certain heating system by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag;

[0112] The composite agglomerates are screened, and the composite agglomerates with a particle size of 30 mm * 50 mm - 50 mm * 80 mm are screened out and arranged on N trolleys through a distributing machine. The trolleys with the material loaded are successively sent into the feeding transfer vehicle every 4 min through a stepping device. The trolleys on the feeding transfer vehicle are transferred into the yellow phosphorus extraction kiln. The inside of the extraction kiln is replaced with nitrogen for 4 min. After the composite agglomerates are preheated to 1000°C, the composite agglomerates are reduced by means of electromagnetic wave heating. The electromagnetic wave power is 400 kw. The composite agglomerates are reduced by electromagnetic wave heating, the temperature rises to 1000°C, and it is kept warm for 3 h to allow the phosphorus vapor to escape;

[0113] After the composite mass is cooled to below 200 °C, the yellow phosphorus extraction kiln is replaced with nitrogen again for 4 minutes, then the trolley is transferred to the discharge transfer car, and the trolley is transferred to the rotary track through the discharge transfer car. The solid slag cooled to below 40 °C after reduction is discharged through the unloader, then distributed by the distributor, and the feed transfer car is sent into the yellow phosphorus extraction kiln through the stepping device, and this cycle repeats.

[0114] S3: The phosphorus vapor is recovered through the phosphorus recovery system, enters the phosphorus collection tank after being sprayed and condensed by a multi-stage cooling tower, and the yellow phosphorus discharged from the phosphorus collection tank is condensed and rinsed after being repeatedly rinsed with hot water or steam to obtain yellow phosphorus. The solid slag is cooled in the furnace by 35 °C and discharged through the unloader.

[0115] After analysis, the residual phosphorus content in the solid slag is 7.87%, far higher than the requirement that the residual phosphorus content in the solid slag of the composite mass in the present invention is lower than 1%. The yellow phosphorus energy consumption is 8100 kwh / t of product, the phosphorus ore raw material required is 7.8 t / t of product, the slag amount generated is 5.9 t / t of product, and the purity of primary yellow phosphorus is 91.6%.

[0116] Comparative Example 2

[0117] Yellow phosphorus is produced in this comparative example through the following steps:

[0118] S1: The phosphorus ore is crushed to 15 mm, the coke to 6 mm, and the silica to 15 mm by a crusher.

[0119] Among them, the P2O5 content in the phosphorus ore is 32%; the carbon content of the coke reducing agent is 80%, and the silica content in the silica is 95%;

[0120] The ratio of phosphorus ore, coke, and silica is 100∶20∶10.

[0121] S2: After the raw materials enter the dryer for drying, they are automatically weighed and proportioned. The mixed raw materials are sent to the central hopper on the top of the electric furnace through a bucket elevator. The central hopper on the top of the electric furnace distributes the proportioned raw materials to each electric furnace hopper through the distribution system, and are added into the electric furnace through the feed pipe by the automatic control system. The furnace charge melts and undergoes a decomposition and reduction reaction at a high temperature of 1480 °C in the furnace. The phosphorus vapor enters the scrubber together with the furnace gas through the conduit, is condensed into droplets, and falls to the bottom of the tower together with the dust and water, and is collected in the phosphorus receiving tank. The crude phosphorus containing impurities in the phosphorus receiving tank is periodically siphoned into the refining tank, heated by steam, kept warm, rinsed, and settled at a temperature of 60 °C, then left to stand. The refined phosphorus obtained through refining is siphoned into the packaging barrel through a rubber hose for metering and packaging, and thus the finished yellow phosphorus is obtained.

[0122] S3: The slag is discharged through the slag discharge port, automatically enters the slag pond through the slag chute, and the high-temperature slag is quenched into granular form and cooled in the slag pond. Then, it is grabbed out of the slag pond by a grab bucket, drained, and transported to the phosphorus slag yard for temporary storage by a truck.

[0123] Through analysis, the residual phosphorus content in the solid slag is 1.8%, the yellow phosphorus energy consumption is 14500 kwh / t of product, the phosphorus ore raw material required is 9.5 t / t of product, the slag production is 7.8 t / t of product, and the primary yellow phosphorus purity is 84.6%.

[0124] Example 5

[0125] This example provides an electromagnetic wave heating furnace device, as Figure 2 and Figure 3 shown.

[0126] The electromagnetic wave heating furnace device of this example includes an electromagnetic wave generator 1, a dual directional coupler 2, a water-containing load circulator 3, a straight or curved waveguide 4, a power distributor 5, a three-screw tuner 6, a water-cooled energy feeding port 7, a continuous electromagnetic wave heating furnace 8, a power supply control system 9, a propulsion trolley 10 with a propulsion device, a wave-inducing material 11, an electromagnetic wave penetration layer 12, a heat insulation layer 13, and an electromagnetic wave suppression layer 14;

[0127] The electromagnetic wave generator 1 enters the water-cooled energy feeding port 7 through the straight or curved waveguide 4 and is input into the continuous electromagnetic wave heating furnace 8 from the top;

[0128] The power distributor 5 adjusts the power distribution through the three-screw tuner 6;

[0129] The upper side of the propulsion trolley 10 with a propulsion device is provided with a wave-inducing material 11;

[0130] The power supply control system 9 is arranged on the top of the base;

[0131] The electromagnetic wave generator 1, the water-containing load circulator 3, the straight or curved waveguide 4, the power distributor 5, the water-cooled energy feeding port 7, and the top of the continuous electromagnetic wave heating furnace 8 are all connected by bolts;

[0132] The electromagnetic wave generator 1 is divided into two paths through the power distributor 5 through the straight or curved waveguide 4 and enters the water-cooled energy feeding port 7 and is input into the continuous electromagnetic wave heating furnace 8 from the top;

[0133] An electromagnetic wave penetration layer 12 and a heat insulation layer 13 are arranged in the electromagnetic wave heating furnace 1; the electromagnetic wave penetration layer 12 is arranged on the top of the electromagnetic wave heating furnace 1, and the heat insulation layer 13 is arranged on the side wall of the electromagnetic wave heating furnace 1; an electromagnetic wave suppression layer 14 is arranged on the outer wall of the electromagnetic wave heating furnace 1;

[0134] A plurality of temperature detection devices 15 and pressure detection devices 16 are arranged inside the electromagnetic wave heating furnace 1; the temperature detection devices 15 and pressure detection devices 16 are arranged inside the heat preservation layer 13, and the temperature detection devices 15 and pressure detection devices 16 are interlocked with the power control system to realize dynamic control of the process;

[0135] The power control system 9 includes a controller 17, a temperature sensor 18, a power regulator 19, and an electromagnetic wave generator start / stop device 20. The controller 17, the temperature sensor 18, the power regulator 19, and the electromagnetic wave generator start / stop device 20 are arranged on the power control system 9, and the controller 17, the temperature sensor 18, the power regulator 19, and the electromagnetic wave generator start / stop device 20 are correspondingly connected to each other through wires;

[0136] In the electromagnetic wave heating furnace device of this embodiment, components such as the temperature detection device, the pressure detection device, the controller, the temperature sensor, the power regulator, and the electromagnetic wave generator start / stop device involved in its composition structure are all general standard parts or parts known to those skilled in the art.

[0137] When the composite agglomerate in Embodiments 1-4 is reduced by the electromagnetic wave heating furnace device of this embodiment, the electromagnetic wave device is turned on. By setting the process temperature curve, the power control system will automatically adjust the power, realizing the conversion of electrical energy generated by the electromagnetic wave generator into electromagnetic wave energy, and then the conversion of electromagnetic wave energy into the heat energy of the composite agglomerate. The composite agglomerate on the trolley in the electromagnetic wave heating furnace enters the electromagnetic wave area and rapidly heats up. After the phosphorus vapor is vaporized, it is extracted from the composite agglomerate and enters the subsequent phosphorus vapor recovery system through the air outlet pipe, thus forming the extraction and recovery of phosphorus vapor;

[0138] At the same time, the electromagnetic wave generator can be divided into two paths through a straight or curved waveguide, passed through a power distributor, and then enter the water-cooled energy feeding port and be input into the continuous electromagnetic wave heating furnace from the top. In this way, the power is evenly distributed to the two output ports, reducing the concentration of electromagnetic wave energy and extending the service life of the electromagnetic wave penetration layer and the heat preservation layer in the electromagnetic wave heating furnace.

[0139] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for producing yellow phosphorus, characterized in that, It includes the following steps: S1: Grind the phosphate mineral and the siliceous reducing agent separately to obtain phosphate ore powder and siliceous reducing agent powder. Mix the phosphate ore powder and the siliceous reducing agent powder according to a certain ratio, then mix them evenly through a mixer, and then cold press them into blocks to obtain composite briquettes; S2: Screen the composite briquettes, arrange the qualified composite briquettes after screening on the trolley through a distributing machine, and enter the yellow phosphorus extraction kiln. Heat up and keep warm according to a certain heating system by means of electromagnetic wave heating to obtain phosphorus vapor and solid slag; S3: Recover the phosphorus vapor through a phosphorus recovery system, and obtain yellow phosphorus after condensation and rinsing. The solid slag is cooled in the furnace to a specified temperature and discharged through a discharger.

2. The method for producing yellow phosphorus according to claim 1, wherein In step S1, the phosphate mineral is phosphate rock, the P2O5 content in the phosphate rock is 25% - 35%, and the particle size of the phosphate rock is ≤ 20mm.

3. The method for producing yellow phosphorus according to claim 2, characterized in that, In step S1, the siliceous reducing agent is one or more of industrial silicon, silica fume or other siliceous reducing agents; For the industrial silicon, the silicon content is ≥ 99%; for the silica fume, the silicon content is 90% - 93%, and for the other siliceous reducing agents, the silicon content is ≥ 80%.

4. The method for producing yellow phosphorus according to claim 3, characterized in that, In step S1, the fineness of the phosphate ore powder and the siliceous reducing agent powder is 100 - 200 mesh; The ratio of the phosphate ore powder to the siliceous reducing agent powder is 100∶12 - 20.

5. The method for producing yellow phosphorus according to claim 4, characterized in that, In step S2, the electromagnetic wave heating is realized through an electromagnetic wave heating furnace device; The electromagnetic wave heating furnace device includes an electromagnetic wave generator, a bi-directional coupler, a water-containing load circulator, a straight or curved waveguide, a power distributor, a three-screw tuner, a water-cooled energy feeding port, a continuous electromagnetic wave heating furnace, a power supply control system, a propulsion trolley with a propulsion device, wave-trapping material, an electromagnetic wave penetration layer, a heat preservation layer and an electromagnetic wave suppression layer.

6. The method for producing yellow phosphorus according to claim 5, characterized in that, In step S2, the particle size of the composite briquette is 30mm * 50mm - 50mm * 80mm.

7. The method for producing yellow phosphorus according to claim 6, characterized in that, In step S2, the electromagnetic wave heating temperature is 1100℃ - 1150℃, and the heat preservation time is 1 - 4h.

8. The method for producing yellow phosphorus according to claim 6, characterized in that, In step S2, the electromagnetic wave heating power is 300 - 400kW.

9. The method for producing yellow phosphorus according to claim 8, wherein, In step S3, the specified temperature is ≤ 40℃.

10. A heating device for producing yellow phosphorus, which is used in the method for producing yellow phosphorus according to any one of claims 1-9, characterized in that, It includes an electromagnetic wave generator, a bi-directional coupler, a water-containing load circulator, a straight or curved waveguide, a power distributor, a three-screw tuner, a water-cooled energy feeding port, a continuous electromagnetic wave heating furnace, a power supply control system, a propulsion trolley with a propulsion device, wave-trapping material, an electromagnetic wave penetration layer, a heat preservation layer and an electromagnetic wave suppression layer.

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