Roasting pyrolysis device and phosphorus-containing pellet production system comprising same

Abstract

The utility model provides a roasting pyrolysis device and a phosphorus-containing pellet production system comprising the same. The device comprises a drying section, a roasting section, a cooling section and a pyrolysis chamber, the system comprises a phosphorite crushing and grinding mechanism, a mixing and pelletizing mechanism and the roasting and pyrolyzing device. The device and the system disclosed by the utility model can realize efficient removal of carbonate in a phosphorite raw material at low cost without influencing normal production and processing of pellets, but can effectively reduce the pulverization rate of artificial pellets, improve the yield and the strength of the pellets, obviously reduce or even completely prevent fine powder from entering an electric furnace, and improve the production efficiency of the pellets. And the stability of yellow phosphorus production is further improved and guaranteed. In addition, the device also has the advantages of no extra energy consumption, simple structure, low occupied area, convenience in maintenance and operation and the like.

Description

Technical Field

[0001] The utility model relates to phosphate ore pellet production and processing equipment, in particular to a roasting and pyrolysis device and a phosphorus-containing pellet production system containing the device, belonging to the technical field of phosphate ore pellet production and processing. Background Art

[0002] Yellow phosphorus is an important chemical product and raw material, and its products are widely used in agriculture, industry, national defense, food, electronics and other fields. Yellow phosphorus production generally adopts the electric furnace method, that is, natural phosphate rock, coke, flux (silica, etc.) are mixed in a three-phase electric furnace according to a certain proportion, and then melt-reduced at a high temperature of 1400-1500 degrees Celsius. Traditional yellow phosphorus production uses 5-90mm natural phosphate lumps. Domestic yellow phosphorus plants are limited by funds, equipment and technical levels. When using phosphate lumps, most of them use simple crushing, drying, screening and other pretreatment before using them in electric furnace production. This technical route mainly faces the following difficulties: (1) Natural phosphate rock is a non-renewable resource. After decades of mining and utilization, high-quality phosphate lumps with high quality and few impurities are becoming increasingly scarce. Its market price has also risen with the hot yellow phosphorus market in recent years, and its price continues to run at a high level; (2) Phosphate rock also contains a certain amount of carbonate , and carbonate decomposes in the upper part of the electric furnace. On the one hand, the decomposition reaction reduces the strength of the lump ore, breaks it into fine particles, and increases the amount of mud phosphorus. On the other hand, its decomposition absorbs heat and the CO2 produced reacts with the coke in the electric furnace to produce Boudol reaction, resulting in additional consumption of energy such as electricity and coke; (4) Most of my country's phosphate resources are weathered calcareous phosphate ores, and the strength of the lump ore is relatively low. During the ore mining, transportation, and in-plant drying and screening processes, 20%-50% of powder ore is produced that cannot be directly used by the electric furnace. The powder ore is piled up in large quantities or sold at low prices, resulting in a waste of phosphate resources. Therefore, the use of natural phosphorus lump ore for yellow phosphorus production is increasingly unable to meet the current industrial requirements for efficient and green production.

[0003] In order to solve the shortcomings of using natural phosphate ore to produce yellow phosphorus, researchers have proposed a method of preparing molded agglomerates using waste phosphate rock powder. However, in order to improve the strength of raw or finished agglomerates to meet production and transportation requirements, various binders and additives (such as sodium humate, inorganic acids, etc.) need to be added. The cost of binders is very high, the adaptability of mineral powders varies greatly, and additives may change the conductive properties of the ore and affect subsequent electric furnace operations. In addition, only the compressive strength of the molded agglomerates is concerned. The agglomerates have insufficient wear resistance during transportation, the carbonates are not completely removed, and there is a lack of processing equipment that can effectively overcome the above problems. Utility Model Content

[0004] Aiming at the shortcomings of the prior art that the carbonate content of the finished pellets is high, which affects the quality of the pellets and the subsequent smelting and phosphorus production, due to the lack of equipment for quickly removing carbonates from the phosphate ore raw materials during processing without affecting the normal production and processing of the phosphate ore pellets, the utility model provides a roasting pyrolysis device and a phosphorus-containing pellet production system containing the device, which can realize the efficient removal of carbonates from the phosphate ore raw materials at a low cost, without affecting the normal production and processing of the pellets, but can effectively reduce the pulverization rate of artificial pellets, improve the yield and strength of the pellets, significantly reduce or even completely avoid the entry of fine powder into the electric furnace, thereby improving and ensuring the stability of yellow phosphorus production. In addition, the utility model also has the advantages of no additional energy consumption, simple structure, low site occupation, and convenient maintenance and operation.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the utility model are as follows:

[0006] According to the first embodiment of the utility model, a roasting pyrolysis device is provided:

[0007] A roasting and pyrolysis device, comprising a drying section, a roasting section, a cooling section and a pyrolysis chamber. According to the direction of the material, the drying section, the roasting section and the cooling section are arranged in series in sequence. The pyrolysis chamber is arranged outside the roasting section, and the hot air inlet of the pyrolysis chamber is connected to the hot air outlet of the roasting section through a second heat return air duct, and the hot air outlet of the pyrolysis chamber is connected to the hot air inlet of the drying section through a third heat return air duct. The hot air outlet of the cooling section is connected to the hot air inlet of the roasting section through a first heat return air duct.

[0008] Preferably, the drying section comprises a plurality of drying branches connected in series, and the hot air inlet of each drying branch is connected to the third hot air return pipe through an independent hot air branch pipe. An air volume regulating valve is independently arranged on each hot air branch pipe.

[0009] Preferably, the drying section includes drying section 1, drying section 2 and drying section 3 which are arranged in series. Each hot air branch pipe connected to drying section 1, drying section 2 and drying section 3 is also independently connected to a cold air supply pipe. Wind temperature detectors are also independently arranged in drying section 1, drying section 2 and drying section 3.

[0010] Preferably, the device further comprises a rotary cooling drum. According to the direction of the material, the rotary cooling drum is arranged downstream of the cooling section, and the feed end of the rotary cooling drum is connected to the discharge end of the cooling section through a discharge chute. A cooling air inlet is also arranged at the discharge end of the rotary cooling drum, and a hot air outlet is also arranged at the feed end of the rotary cooling drum and is connected to the air inlet of the cooling section through a fourth heat recovery air duct.

[0011] Preferably, the rotary cooling drum is arranged in an oblique horizontal position with the discharge end being lower than the feed end.

[0012] Preferably, the device further comprises a screening machine. According to the direction of the material, the screening machine is arranged downstream of the discharge end of the rotary cooling drum, and the feed end of the screening machine is located below the discharge end of the rotary cooling drum. The screened material outlet of the screening machine is connected to the return ore buffer bin through the return material feeding mechanism, and the screened material outlet of the screening machine is connected to the finished product buffer bin through the finished product feeding mechanism.

[0013] Preferably, the sieve hole diameter of the screening machine is not greater than 10 mm, preferably 5-10 mm, more preferably 8-10 mm.

[0014] In the utility model, a drying section, a roasting section and a cooling section are provided to realize high-temperature consolidation of raw pellets of artificial phosphate ore powder, thereby obtaining qualified finished phosphorus-containing pellets that prevent yellow phosphorus from entering the furnace for production. At the same time, a pyrolysis chamber is provided on the outside of the roasting section, and the high-temperature hot exhaust gas discharged from the roasting section is directly transported into the pyrolysis chamber to realize pyrolysis treatment of the raw phosphate ore lump (or fine-particle ore powder). The carbonate in the raw phosphate ore lump (or fine-particle ore powder) is removed through the pyrolysis treatment, and the waste heat of the high-temperature hot exhaust gas is utilized at the same time without consuming additional energy. The raw phosphate ore lump (large particles) after the carbonate is removed can directly enter the electric furnace for yellow phosphorus production. Since the carbonate is removed in advance, the adverse effects caused by the thermal decomposition of the carbonate in the electric furnace are avoided, thereby maintaining and ensuring The stability of electric furnace production; the fine-particle ore powder from which carbonates have been removed can be further ground and used as a pelletizing raw material for the production of phosphorus-containing pellets. In addition, since carbonates have been removed in advance, the green pellets are almost not affected by the thermal decomposition of carbonates during the roasting process, avoiding the fragmentation and pulverization of the green pellets during the consolidation process, effectively ensuring and improving the strength of the finished pellets (by pre-removing crystal water and carbonates, generating internal cracks and thermal cracks during the high-temperature process, reducing the impact of impurity decomposition on pellet consolidation, improving pellet consolidation strength and reducing subsequent grinding energy consumption; in addition, it plays a buffering role when switching from the drying stage to the roasting stage, avoiding the green balls from bursting or cracking due to incomplete drying and sudden temperature rise, thereby improving the quality of pellet ore) and output, while reducing energy consumption.

[0015] In the utility model, the hot air discharged from the cooling section is used as the combustion-supporting air of the roasting section, and then the hot air discharged from the roasting section is used as the heat source of the pyrolysis chamber, and finally the hot air discharged from the pyrolysis chamber is used as the drying hot air of the drying section. By using the airflows of each section and chamber in series, the utilization efficiency of the hot air is improved, and the energy consumption and waste heat emission are reduced. It should be noted that the hot air discharged from the roasting section has a relatively high temperature, so it cannot be used directly as the drying air. It needs to be mixed with a large amount of cold air to reduce the air temperature before it can be used for drying. The addition of a large amount of cold air increases the emission of waste hot air after drying on the one hand, and significantly reduces the utilization efficiency of the waste heat of the hot air on the other hand. Therefore, by using the hot air after roasting as the hot air for the pyrolysis chamber, the heat absorption during the pyrolysis of carbonates and the heat absorption of the ore itself due to the temperature rise make the hot air temperature lower. It can be directly used in the drying process of green pellets without adding cold air (or adding a small amount), realizing the efficient utilization of waste heat cascade and significantly reducing the total amount of waste gas emissions.

[0016] In the utility model, the drying section includes drying section one, drying section two and drying section three, and the three sections are independently fed with air (the air temperature and wind speed are both stepped), that is, through multi-stage hot air drying with stepped temperature and stepped wind speed (the air volume of cold air in each drying section and the hot air returned from roasting are regulated to adjust the temperature and wind speed of the drying medium), the drying temperature of each section is gradually increased (130°C-500°C), the drying wind speed is gradually accelerated (1.0m / s-2.0m / s), and the total drying time is shortened to 5min-15min; the roasting stage adopts high temperature (1 The method adopts the roasting temperature of 000℃-1200℃), high wind speed (1.8m / s-2.6m / s), thin material layer (the thickness of the raw phosphate pellet material layer is 150mm-200mm), and short time (6min-12min). The high temperature and high wind speed accelerate the consolidation and feeding of the phosphate pellets, improve the decomposition rate of residual carbonate, and use a thin material layer to reduce the temperature difference between the upper and lower material layers, so that the temperature distribution of the entire material layer covers the suitable temperature range for pellet consolidation, improves the consolidation strength of the phosphate pellets, shortens the roasting time, and reduces the length of equipment and investment.

[0017] In the present invention, the three-stage step drying is generally as follows: the hot air temperature of the first stage of drying is 130-200°C, the hot air speed is 1-1.2m / s, and the drying time is 1-3min. The hot air temperature of the second stage of drying is 200-350°C, the hot air speed is 1.2-1.5m / s, and the drying time is 2-5min. The hot air temperature of the third stage of drying is 350-500°C, the hot air speed is 1.5-2m / s, and the drying time is 3-7min.

[0018] In the utility model, in the cooling stage, cold air is generally used to heat exchange and cool the high-temperature materials after roasting. The cooling section uses blast cooling on the machine to cool the temperature of the roasted material layer from more than 1000°C to no more than 300°C (i.e., one-time cooling) or even lower. The hot air after cooling in the cooling section enters the roasting section as combustion air to improve energy utilization.

[0019] In the utility model, secondary cooling (i.e., rotary cooling drum cooling) is also included. The rotary cooling drum cooling is carried out in the rotary drum. Cold air is used as a cooling medium to cool the material after primary cooling to below 100°C again (i.e., secondary cooling). The hot air after secondary cooling can be returned to the primary cooling stage as a primary cooling medium to improve energy utilization. At the same time, during the secondary cooling process, the phosphate ore pellets rotate in the rotary drum, and the pellets and the drum wall are constantly rubbed to remove small particles that are not firmly consolidated on the surface of the pellets, thereby improving the drum and wear resistance of the finished phosphate ore pellets. After cooling is completed, screening treatment is carried out. Screening generally uses 10mm aperture screening to separate the powder <10mm produced in the drying, roasting and secondary cooling pre-grinding stages from the finished phosphate ore pellets >10mm. The powder <10mm is returned to the mixed grinding, and the pellets >10mm are used as the finished phosphate ore pellets for yellow phosphorus smelting. The compressive strength is >1000N and the drum strength is ≥95%.

[0020] According to a second embodiment of the present invention, a phosphorus-containing pellet production system is provided:

[0021] A phosphorus-containing pellet production system, the system comprises a phosphate ore crushing and grinding mechanism, a mixing and pelletizing mechanism, and a roasting and pyrolysis device as described in the first embodiment. The phosphate ore crushing and grinding mechanism, the mixing and pelletizing mechanism, and the roasting and pyrolysis device are sequentially arranged in series. The material outlet of the pyrolysis chamber is connected to the feed inlet of the phosphate ore crushing and grinding mechanism through a return material conveying mechanism.

[0022] Preferably, the phosphate ore crushing and grinding mechanism comprises a crusher, a grinder, a screener and a plurality of mineral powder buffer bins connected in series. The feed port of the crusher is connected to the discharge end of the return material conveying mechanism. The under-screen material outlet of the screener is connected to the feed ends of the plurality of mineral powder buffer bins through a belt conveyor, and the over-screen material outlet of the screener is connected to the feed port of the crusher through a circulating crushing and feeding mechanism.

[0023] Preferably, the mesh size of the ore screening machine is 120-200 mesh, preferably 130-180 mesh.

[0024] Preferably, the mixing and pelletizing mechanism comprises a mixing and batching barrel and a pelletizing machine which are sequentially connected in series. The feed port of the mixing and batching barrel is connected to the discharge ends of several mineral powder buffer bins through a belt conveyor. The discharge port belt conveyor of the pelletizing machine is connected to the distribution port of the roasting and pyrolysis device.

[0025] Preferably, a pellet screening machine is provided between the pelletizing machine and the roasting and pyrolysis device. The feed end of the pellet screening machine is connected to the discharge end of the pelletizing machine, the screen material outlet of the pellet screening machine is connected to the material distribution port of the roasting and pyrolysis device, and the screen material outlet of the pellet screening machine is connected to the feed port of the crusher through a bulk material conveying mechanism.

[0026] Preferably, the pelletizing machine is a disc pelletizing machine and / or a cylinder pelletizing machine.

[0027] Preferably, the sieve hole diameter of the pellet screening machine is 10-20 mm, preferably 12-15 mm.

[0028] In the utility model, the fine-grained phosphorus-containing ore particles that cannot be directly used (such as for preparing yellow phosphorus in an electric furnace) can be decarbonized (removed from carbonate) through a pyrolysis chamber and then crushed into powder. Then, according to the working condition requirements, a variety of powders are used for batching and balling and roasting are performed in sequence to obtain artificial phosphorus-containing pellets with excellent performance that can be directly used for producing yellow phosphorus in an electric furnace. While improving the efficient utilization of phosphorus resources, the problem of waste of land resources and environmental pollution caused by the accumulation of a large number of fine-grained waste phosphorus ore particles is solved. By removing carbonate in advance, on the one hand, the problem of serious pulverization and fragmentation and high energy consumption caused by the high carbonate content in the raw pellets prepared directly using phosphate rock powder during the roasting process can be reduced. At the same time, it is also beneficial to improve the strength of the phosphorus-containing pellets, and further completely avoid the phenomenon of carbonate entering the yellow phosphorus production furnace with the phosphorus-containing pellets and causing the pulverization of the furnace charge, improving the product quality and reducing the production energy consumption, that is, solving the problems of the current high yield of fine-grained phosphorus-containing powder that cannot be used, the high extra heat consumption of the decomposition of carbonate in phosphorus block ore, and the unstable adjustment of the furnace charge acidity. In addition, large-particle phosphate lumps can be directly pyrolyzed in a pyrolysis chamber to obtain decarbonized phosphorus lumps, and then the decarbonized phosphorus lumps can be directly fed into an electric furnace to produce phosphorus.

[0029] In the utility model, the utility model can be applied to almost all phosphorus-containing ores in the process of phosphate mining, so that the production of phosphorus-containing pellets has the characteristics of better particle size range and accurate particle size lower limit control. At present, the natural block ore used in the existing technology for producing yellow phosphorus is generally screened with a lower limit of 5mm or even 4mm after drying, but due to the low screening efficiency, the phosphate ore entering the electric furnace is mixed with a certain amount of powder less than 5mm, and the presence of these powders will deteriorate the permeability of the furnace charge. The phosphorus-containing pellets provided by the present invention are artificial phosphorus-containing pellets, and their minimum particle size can be increased to about 10mm. Compared with the currently used phosphorus block ore, the particle size is larger and more uniform, and there is no -5mm powder entering the furnace, which can significantly improve the permeability of the material column in the electric furnace and the efficiency of phosphorus vapor rising.

[0030] In the utility model, the phosphorus-containing pellets prepared by the utility model have a grade (P2O5) of ≥20wt% (the grade is equivalent to or slightly higher than the grade of natural block ore or molded charge currently used in electric furnaces, which fully meets the smelting requirements of electric furnaces), a particle size of 10mm-40mm, a compressive strength of ≥1000N, a drum strength of not less than 95% (not only can it meet the compressive strength requirements of yellow phosphorus electric furnaces for charge, but also the wear resistance is significantly higher than that of natural block ore (60%-75%), and the amount of powder generated during transportation can be reduced by more than 50% compared with phosphorus block ore, so it is more resistant to long-distance transportation and can be circulated as a commodity in the market, increasing the income channels for yellow phosphorus production enterprises), and a carbonate content of not more than 0.2wt% (compared with natural block ore, the heat consumed by carbonate decomposition is greatly reduced, and at the same time, charge pulverization and increase in mud phosphorus caused by carbonate decomposition are completely avoided), which fully meets the requirements of yellow phosphorus electric furnaces for charge.

[0031] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0032] 1: The utility model can realize the efficient utilization of the whole amount of phosphate ore, and at the same time, the obtained pellets have low carbonate content and good strength. When used as yellow phosphorus smelting furnace charge, the heat loss is low, the pulverization rate is low, and the amount of mud phosphorus is small.

[0033] 2: The utility model significantly improves the waste heat utilization efficiency through the hot air cascade circulation, and also greatly reduces the emission of waste heat and exhaust gas. At the same time, it can remove carbonate and moisture in phosphorus-containing raw materials at low cost and high efficiency without additional energy consumption, creating favorable conditions for subsequent pellet production and yellow phosphorus production.

[0034] 3: The device and system of the utility model have simple structure, small site occupation, low investment and maintenance cost, convenient operation, high production and waste heat utilization efficiency, low energy consumption, and are relatively friendly to the environment, and have excellent prospects for large-scale industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1It is a structural schematic diagram of the roasting and pyrolysis device of the utility model.

[0036] Figure 2 It is a structural schematic diagram of the phosphorus-containing pellet production system of the utility model.

[0037] Reference numerals: 1: drying section; 101: drying section 1; 102: drying section 2; 103: drying section 3; 104: hot air branch pipe; 105: cold air supply pipe; 2: roasting section; 3: cooling section; 4: pyrolysis chamber; 5: rotary cooling drum; 6: screening machine; 601: return material feeding mechanism; 602: finished product feeding mechanism; 7: return ore buffer; 8: finished product buffer; 9: phosphate ore crushing and grinding mechanism; 901: crushing Crusher; 902: grinding mill; 903: ore screening machine; 904: mineral powder buffer bin; 905: circulating crushing and feeding mechanism; 10: mixing and pelletizing mechanism; 1001: mixing and batching barrel; 1002: pelletizing machine; 1003: pelletizing screening machine; 1004: bulk material conveying mechanism; 11: return material conveying mechanism; H1: first reheat air duct; H2: second reheat air duct; H3: third reheat air duct; H4: fourth reheat air duct. DETAILED DESCRIPTION

[0038] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.

[0039] A roasting and pyrolysis device, comprising a drying section 1, a roasting section 2, a cooling section 3 and a pyrolysis chamber 4. According to the direction of the material, the drying section 1, the roasting section 2 and the cooling section 3 are arranged in series in sequence. The pyrolysis chamber 4 is arranged outside the roasting section 2, and the hot air inlet of the pyrolysis chamber 4 is connected to the hot air outlet of the roasting section 2 through the second hot air return duct H2, and the hot air outlet of the pyrolysis chamber 4 is connected to the hot air inlet of the drying section 1 through the third hot air return duct H3. The hot air outlet of the cooling section 3 is connected to the hot air inlet of the roasting section 2 through the first hot air return duct H1.

[0040] Preferably, the drying section 1 comprises a plurality of drying branches connected in series, and the hot air inlet of each drying branch is connected to the third hot air return pipe H3 through an independent hot air branch pipe 104. Each hot air branch pipe 104 is independently provided with an air volume regulating valve.

[0041] Preferably, the drying section 1 comprises a drying section 101, a drying section 102 and a drying section 103 which are arranged in series. Each hot air branch pipe 104 connected to the drying section 101, the drying section 102 and the drying section 103 is also independently connected to a cold air supply pipe 105. Wind temperature detectors are also independently arranged in the drying section 101, the drying section 102 and the drying section 103.

[0042] Preferably, the device further comprises a rotary cooling drum 5. According to the direction of the material, the rotary cooling drum 5 is arranged downstream of the cooling section 3, and the feed end of the rotary cooling drum 5 is connected to the discharge end of the cooling section 3 through a discharge chute. A cooling air inlet is also arranged at the discharge end of the rotary cooling drum 5, and a hot air outlet is also arranged at the feed end of the rotary cooling drum 5 and is connected to the air inlet of the cooling section 3 through the fourth hot air return pipe H4.

[0043] Preferably, the rotary cooling cylinder 5 is arranged in an oblique horizontal position with the discharge end being lower than the feed end.

[0044] Preferably, the device further comprises a screening machine 6. According to the direction of the material, the screening machine 6 is arranged downstream of the discharge end of the rotary cooling drum 5, and the feed end of the screening machine 6 is located below the discharge end of the rotary cooling drum 5. The screened material outlet of the screening machine 6 is connected to the return ore buffer bin 7 through the return material feeding mechanism 601, and the screened material outlet of the screening machine 6 is connected to the finished product buffer bin 8 through the finished product feeding mechanism 602.

[0045] Preferably, the sieve hole diameter of the screening machine 6 is not greater than 10 mm, preferably 5-10 mm, more preferably 8-10 mm.

[0046] A phosphorus-containing pellet production system, the system comprises a phosphate ore crushing and grinding mechanism 9, a mixing and pelletizing mechanism 10 and a roasting and pyrolysis device as described above. The phosphate ore crushing and grinding mechanism 9, the mixing and pelletizing mechanism 10 and the roasting and pyrolysis device are sequentially arranged in series. The material outlet of the pyrolysis chamber 4 is connected to the feed port of the phosphate ore crushing and grinding mechanism 9 through a return material conveying mechanism 11.

[0047] Preferably, the phosphate ore crushing and grinding mechanism 9 comprises a crusher 901, a grinding machine 902, a sifter 903 and a plurality of mineral powder buffer bins 904 connected in series in sequence. The feed port of the crusher 901 is connected to the discharge end of the return material conveying mechanism 11. The under-screen material outlet of the sifter 903 is respectively connected to the feed ends of the plurality of mineral powder buffer bins 904 through a belt conveyor, and the over-screen material outlet of the sifter 903 is connected to the feed port of the crusher 901 through a circulating crushing and feeding mechanism 905.

[0048] Preferably, the mesh size of the ore screening machine 903 is 120-200 mesh, preferably 130-180 mesh.

[0049] Preferably, the mixing and pelletizing mechanism 10 comprises a mixing and batching barrel 1001 and a pelletizing machine 1002 which are sequentially arranged in series. The feed port of the mixing and batching barrel 1001 is connected to the discharge ends of several mineral powder buffer bins 904 through a belt conveyor. The discharge port belt conveyor of the pelletizing machine 1002 is connected to the distribution port of the roasting and pyrolysis device.

[0050] Preferably, a pellet sieving machine 1003 is further provided between the pelletizing machine 1002 and the roasting and pyrolysis device. The feed end of the pellet sieving machine 1003 is connected to the discharge end of the pelletizing machine 1002, the screened material outlet of the pellet sieving machine 1003 is connected to the material distribution port of the roasting and pyrolysis device, and the screened material outlet of the pellet sieving machine 1003 is connected to the feed port of the crusher 901 through the bulk material conveying mechanism 1004.

[0051] Preferably, the pelletizing machine 1002 is a disc pelletizing machine and / or a cylinder pelletizing machine.

[0052] Preferably, the sieve hole diameter of the pellet screening machine 1003 is 10-20 mm, preferably 12-15 mm.

[0053] Example 1

[0054] like Figure 1 As shown, a roasting and pyrolysis device includes a drying section 1, a roasting section 2, a cooling section 3 and a pyrolysis chamber 4. According to the direction of the material, the drying section 1, the roasting section 2 and the cooling section 3 are arranged in series in sequence. The pyrolysis chamber 4 is arranged outside the roasting section 2, and the hot air inlet of the pyrolysis chamber 4 is connected to the hot air outlet of the roasting section 2 through the second hot air return duct H2, and the hot air outlet of the pyrolysis chamber 4 is connected to the hot air inlet of the drying section 1 through the third hot air return duct H3. The hot air outlet of the cooling section 3 is connected to the hot air inlet of the roasting section 2 through the first hot air return duct H1.

[0055] Example 2

[0056] Example 1 is repeated, except that the drying section 1 includes a plurality of drying branches connected in series, and the hot air inlet of each drying branch is connected to the third hot air return pipe H3 through an independent hot air branch pipe 104. Each hot air branch pipe 104 is independently provided with an air volume regulating valve.

[0057] Example 3

[0058] Example 2 is repeated, except that the drying section 1 includes a drying section 101, a drying section 2 102, and a drying section 3 103 which are sequentially connected in series. Each hot air branch pipe 104 connected to the drying section 101, the drying section 2 102, and the drying section 3 103 is also independently connected to a cold air supply pipe 105. Wind temperature detectors are also independently provided in the drying section 101, the drying section 2 102, and the drying section 3 103.

[0059] Example 4

[0060] Example 3 is repeated, except that the device further includes a rotary cooling drum 5. According to the direction of the material, the rotary cooling drum 5 is arranged downstream of the cooling section 3, and the feed end of the rotary cooling drum 5 is connected to the discharge end of the cooling section 3 through a discharge chute. A cooling air inlet is also arranged at the discharge end of the rotary cooling drum 5, and a hot air outlet is also arranged at the feed end of the rotary cooling drum 5 and is connected to the air inlet of the cooling section 3 through the fourth hot air return pipe H4.

[0061] Example 5

[0062] Example 4 was repeated, except that the rotary cooling cylinder 5 was arranged in an oblique horizontal position with the discharge end being lower than the feed end.

[0063] Example 6

[0064] Example 5 is repeated, except that the device further includes a screening machine 6. According to the direction of the material, the screening machine 6 is arranged downstream of the discharge end of the rotary cooling drum 5, and the feed end of the screening machine 6 is located below the discharge end of the rotary cooling drum 5. The screened material outlet of the screening machine 6 is connected to the return ore buffer bin 7 through the return material feeding mechanism 601, and the screened material outlet of the screening machine 6 is connected to the finished product buffer bin 8 through the finished product feeding mechanism 602.

[0065] Example 7

[0066] Example 6 was repeated except that the sieve hole diameter of the sieving machine 6 was 5 mm.

[0067] Example 8

[0068] Example 6 was repeated except that the sieve hole diameter of the sieving machine 6 was 8 mm.

[0069] Example 9

[0070] Example 6 was repeated except that the sieve hole diameter of the sieving machine 6 was 10 mm.

[0071] Example 10

[0072] like Figure 2 As shown, a phosphorus-containing pellet production system includes a phosphate ore crushing and grinding mechanism 9, a mixing and pelletizing mechanism 10, and a roasting and pyrolysis device as described in Example 9. The phosphate ore crushing and grinding mechanism 9, the mixing and pelletizing mechanism 10, and the roasting and pyrolysis device are sequentially arranged in series. The material outlet of the pyrolysis chamber 4 is connected to the feed port of the phosphate ore crushing and grinding mechanism 9 through a return material conveying mechanism 11.

[0073] Embodiment 11

[0074] Example 10 is repeated, except that the phosphate ore crushing and grinding mechanism 9 includes a crusher 901, a grinder 902, a screener 903 and a plurality of mineral powder buffer bins 904 connected in series. The feed port of the crusher 901 is connected to the discharge end of the return material conveying mechanism 11. The under-screen material outlet of the screener 903 is connected to the feed ends of the plurality of mineral powder buffer bins 904 through a belt conveyor, and the over-screen material outlet of the screener 903 is connected to the feed port of the crusher 901 through a circulating crushing and feeding mechanism 905.

[0075] Example 12

[0076] Example 11 was repeated, except that the mesh size of the ore screening machine 903 was 120 meshes.

[0077] Example 13

[0078] Example 11 was repeated, except that the mesh size of the ore screening machine 903 was 150 meshes.

[0079] Embodiment 14

[0080] Example 13 is repeated, except that the mixing and pelletizing mechanism 10 includes a mixing and batching barrel 1001 and a pelletizing machine 1002 which are sequentially arranged in series. The feed port of the mixing and batching barrel 1001 is connected to the discharge ends of several mineral powder buffer bins 904 through a belt conveyor. The discharge port belt conveyor of the pelletizing machine 1002 is connected to the distribution port of the roasting and pyrolysis device.

[0081] Embodiment 15

[0082] Example 14 was repeated, except that a pellet sieving machine 1003 was further provided between the pelletizing machine 1002 and the roasting and pyrolysis device. The feed end of the pellet sieving machine 1003 was connected to the discharge end of the pelletizing machine 1002, the screened material outlet of the pellet sieving machine 1003 was connected to the material distribution port of the roasting and pyrolysis device, and the screened material outlet of the pellet sieving machine 1003 was connected to the feed port of the crusher 901 through the bulk material conveying mechanism 1004.

[0083] Example 16

[0084] Repeat Example 15, except that the pelletizing machine 1002 is a cylindrical pelletizing machine.

[0085] Embodiment 17

[0086] Repeat Example 15, except that the pelletizing machine 1002 is a disc pelletizing machine.

[0087] Embodiment 18

[0088] Example 17 was repeated, except that the sieve hole diameter of the pellet screening machine 1003 was 10 mm.

[0089] Embodiment 19

[0090] Example 18 was repeated, except that the sieve hole diameter of the pellet screening machine 1003 was 12 mm.

Claims

1. A roasting and pyrolysis device, characterized in that: The device comprises a drying section (1), a roasting section (2), a cooling section (3) and a pyrolysis chamber (4); the drying section (1), the roasting section (2) and the cooling section (3) are arranged in series in sequence according to the direction of the material; the pyrolysis chamber (4) is arranged outside the roasting section (2), and the hot air inlet of the pyrolysis chamber (4) is connected to the hot air outlet of the roasting section (2) through a second hot air return pipe (H2), and the hot air outlet of the pyrolysis chamber (4) is connected to the hot air inlet of the drying section (1) through a third hot air return pipe (H3); and the hot air outlet of the cooling section (3) is connected to the hot air inlet of the roasting section (2) through a first hot air return pipe (H1).

2. The device according to claim 1, characterized in that: The drying section (1) comprises a plurality of drying branch sections connected in series, and the hot air inlet of each drying branch section is connected to the third hot air return pipe (H3) through an independent hot air branch pipe (104); and an air volume regulating valve is independently arranged on each hot air branch pipe (104).

3. The device according to claim 2, characterized in that: The drying section (1) comprises a drying section (101), a drying section (102) and a drying section (103) which are arranged in series in sequence; each hot air branch pipe (104) connected to the drying section (101), the drying section (102) and the drying section (103) is also independently connected to a cold air supply pipe (105); and each drying section (101), the drying section (102) and the drying section (103) is also independently provided with an air temperature detector.

4. The device according to any one of claims 1 to 3, characterized in that: The device also includes a rotary cooling cylinder (5); according to the direction of the material, the rotary cooling cylinder (5) is arranged downstream of the cooling section (3), and the feed end of the rotary cooling cylinder (5) is connected to the discharge end of the cooling section (3) through a discharge chute; a cooling air inlet is also arranged at the discharge end of the rotary cooling cylinder (5), and a hot air outlet is also arranged at the feed end of the rotary cooling cylinder (5) and is connected to the air inlet of the cooling section (3) through a fourth hot air return pipe (H4).

5. The device according to claim 4, characterized in that: The rotary cooling cylinder (5) is arranged in an oblique horizontal position with the discharge end being lower than the feed end.

6. The device according to claim 4, characterized in that: The device also includes a screening machine (6); according to the direction of the material, the screening machine (6) is arranged downstream of the discharge end of the rotary cooling drum (5), and the feed end of the screening machine (6) is located below the discharge end of the rotary cooling drum (5); the screened material outlet of the screening machine (6) is connected to the returned ore buffer bin (7) through a return material feeding mechanism (601), and the screened material outlet of the screening machine (6) is connected to the finished product buffer bin (8) through a finished product feeding mechanism (602).

7. The device according to claim 6, characterized in that: The sieve hole diameter of the screening machine (6) is not greater than 10 mm.

8. The device according to claim 7, characterized in that: The sieve hole diameter of the sieving machine (6) is 5-10 mm.

9. The device according to claim 8, characterized in that: The sieve hole diameter of the sieving machine (6) is 8-10 mm.

10. A phosphorus-containing pellet production system, characterized in that: The system comprises a phosphate ore crushing and grinding mechanism (9), a mixing and pelletizing mechanism (10) and a roasting and pyrolysis device as described in any one of claims 1 to 9; the phosphate ore crushing and grinding mechanism (9), the mixing and pelletizing mechanism (10) and the roasting and pyrolysis device are arranged in series in sequence; the material outlet of the pyrolysis chamber (4) is connected to the feed port of the phosphate ore crushing and grinding mechanism (9) through a return material conveying mechanism (11).

11. The system according to claim 10, characterized in that: The phosphate ore crushing and grinding mechanism (9) comprises a crusher (901), a grinding machine (902), a sieving machine (903) and a plurality of mineral powder buffer bins (904) which are connected in series in sequence; the feed port of the crusher (901) is connected to the discharge end of the return material conveying mechanism (11); the under-screen material outlet of the sieving machine (903) is connected to the feed ends of the plurality of mineral powder buffer bins (904) respectively through a belt conveyor, and the over-screen material outlet of the sieving machine (903) is connected to the feed port of the crusher (901) through a circulating crushing and feeding mechanism (905).

12. The system according to claim 11, characterized in that: The mesh size of the ore screening machine (903) is 120-200 meshes.

13. The system according to claim 12, characterized in that: The mesh size of the ore screening machine (903) is 130-180 meshes.

14. The system according to claim 11, characterized in that: The mixing and pelletizing mechanism (10) comprises a mixing and batching barrel (1001) and a pelletizing machine (1002) which are sequentially connected in series; the feeding port of the mixing and batching barrel (1001) is connected to the discharge ends of a plurality of mineral powder buffer bins (904) via a belt conveyor; and the discharging port belt conveyor of the pelletizing machine (1002) is connected to the distribution port of the roasting and pyrolysis device.

15. The system according to claim 14, characterized in that: A pellet screening machine (1003) is also provided between the pelletizing machine (1002) and the roasting and pyrolysis device; the feed end of the pellet screening machine (1003) is connected to the discharge end of the pelletizing machine (1002), the screened material outlet of the pellet screening machine (1003) is connected to the material distribution port of the roasting and pyrolysis device, and the screened material outlet of the pellet screening machine (1003) is connected to the feed port of the crusher (901) via a bulk material conveying mechanism (1004).

16. The system according to claim 15, characterized in that: The pelletizing machine (1002) is a disc pelletizing machine and / or a cylinder pelletizing machine; and / or The sieve hole diameter of the pellet screening machine (1003) is 10-20 mm.

17. The system according to claim 16, characterized in that: The sieve hole diameter of the pellet screening machine (1003) is 12-15 mm.

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