CN112707377A - System and method for efficiently and continuously producing anhydrous iron phosphate - Google Patents

System and method for efficiently and continuously producing anhydrous iron phosphate Download PDF

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Publication number
CN112707377A
CN112707377A CN202110018193.3A CN202110018193A CN112707377A CN 112707377 A CN112707377 A CN 112707377A CN 202110018193 A CN202110018193 A CN 202110018193A CN 112707377 A CN112707377 A CN 112707377A
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gas
pipe
rotary
iron phosphate
cooling
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骆浩
谭永鹏
赵旭
徐瑞
秦云龙
郭雨
周钰君
王苏
徐立龙
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Tianhua Institute of Chemical Machinery and Automation Co Ltd
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Tianhua Institute of Chemical Machinery and Automation Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/37—Phosphates of heavy metals
    • C01B25/375—Phosphates of heavy metals of iron

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  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Compounds Of Iron (AREA)

Abstract

The invention relates to a system for efficiently and continuously producing anhydrous iron phosphate. The bottom of the arch-breaking feeding barrel is provided with a feeding screw which is connected with a rotary flash evaporation dryer; the rotary flash dryer is connected with a bag-type dust collector and an emptying pipe; one side of the bag-type dust collector is provided with a compressed nitrogen input pipe, the other side of the bag-type dust collector is connected with a tail gas pipe through a draught fan, and the bottom of the bag-type dust collector is connected with a gas-type rotary roasting furnace through a rotary discharge valve; the top of the gas type rotary roasting furnace is provided with a four-way valve connected with a rotary flash dryer, a hearth is connected with a natural gas input pipe and an air input pipe with a combustion-supporting fan, and the tail part of the hearth is connected with a cooling section; the outer wall of the cooling section is provided with a spray cooling pipe which is connected with a cooling water feeding pipe and a cooling water return pipe; and a ferric phosphate output pipe is arranged at the bottom of one side of the cooling section. The invention also discloses a method for producing the anhydrous iron phosphate. The invention can improve the product quality and yield and reduce the cost.

Description

System and method for efficiently and continuously producing anhydrous iron phosphate
Technical Field
The invention relates to the technical field of fuel cells, in particular to a system and a method for efficiently and continuously producing anhydrous iron phosphate.
Background
Compared with a fuel cell, a lithium ion battery has the advantages of high energy density, long service life, high rated voltage, low self-discharge rate and the like, and is a main development object of the energy storage industry at present. The ferric phosphate has stable structure and rich raw materials, is a precursor of a lithium iron phosphate material, and can be independently used as an anode material of a lithium ion battery.
At present, the method of an electric heating roller kiln is mainly adopted for drying and roasting the ferric phosphate dihydrate. Roller kilns are static equipment, and the material is loaded slow moving by the tray, and top and side carry out radiant heating to the material with electric heating, and this equipment has following problem: the tray has the advantages that heat can be transferred only from outside to inside, the temperature of materials inside the tray is lower than the temperature of materials on the surface all the time, the temperature of the materials inside the tray also reaches the required temperature, the heating temperature needs to be artificially increased, energy consumption is unnecessarily increased, and meanwhile, the quality of products inside and outside is not uniform. Due to the fact that the materials are placed statically, in order to enable the internal materials to be heated fully, the stay time needs to reach several days, and therefore the equipment is large in size and low in yield. The material tray needs to be replaced frequently under the alternating action of high temperature and low temperature and the corrosion action of materials, and the equipment maintenance cost is high.
Disclosure of Invention
The invention aims to provide a system for efficiently and continuously producing anhydrous iron phosphate, which improves the product quality and yield and reduces the cost.
The invention aims to solve another technical problem of providing a method for efficiently and continuously producing anhydrous iron phosphate.
In order to solve the problems, the system for efficiently and continuously producing the anhydrous iron phosphate is characterized by comprising the following steps: the system comprises an arch-breaking feeding barrel, a rotary flash evaporation dryer and a gas-fired rotary roasting furnace; the bottom of the arch-breaking feeding barrel is provided with a feeding screw, and the feeding screw is connected with the rotary flash evaporation dryer; the rotary flash evaporation dryer is respectively connected with a bag-type dust collector and an emptying pipe; one side of the bag-type dust collector is provided with a compressed nitrogen input pipe, the other side of the bag-type dust collector is connected with a tail gas pipe through a draught fan, and the bottom of the bag-type dust collector is connected with the gas-type rotary roasting furnace through a rotary discharge valve; the top of the gas-fired rotary roasting furnace is provided with a four-way valve connected with the rotary flash dryer, a hearth is respectively connected with a natural gas input pipe and an air input pipe with a combustion-supporting fan, and the tail part of the hearth is connected with a cooling section; the outer wall of the cooling section is provided with a spray cooling pipe which is respectively connected with a cooling water feeding pipe and a cooling water return pipe; and a ferric phosphate output pipe is arranged at the bottom of one side of the cooling section.
The smooth finish of the inner wall surface of the gas type rotary roasting furnace is 0.4 micron.
A method for efficiently and continuously producing anhydrous iron phosphate comprises the following steps:
conveying a filter cake of iron phosphate dihydrate containing a large amount of free water into a feeding screw through an arch breaking feeding barrel, and feeding the filter cake into a rotary flash evaporation dryer through the feeding screw to obtain pre-dried iron phosphate dihydrate;
secondly, the pre-dried ferric phosphate dihydrate enters a bag-type dust remover along with tail gas, and compressed nitrogen is input into the bag-type dust remover, so that wet tail gas and the pre-dried ferric phosphate dihydrate after dust removal are obtained after gas-solid separation; the moisture-containing tail gas is exhausted by an induced draft fan;
thirdly, the pre-dried ferric phosphate after dust removal enters a feed inlet of a gas type rotary roasting furnace through a rotary discharge valve, meanwhile, natural gas is input into a hearth of the gas type rotary roasting furnace, air is input through a combustion fan, and high-temperature roasting is carried out at the temperature of 600-800 ℃, so that roasted anhydrous ferric phosphate and heat-exchanged high-temperature flue gas are respectively obtained; the high-temperature flue gas after heat exchange returns to the rotary flash evaporation dryer through a four-way valve to pre-dry the high-moisture material;
and fourthly, the roasted anhydrous ferric phosphate enters a cooling section, and the anhydrous ferric phosphate is cooled in a mode that cooling water is sprayed on the outer wall of the cooling section, so that the cooled ferric phosphate is obtained.
Compared with the prior art, the invention has the following advantages:
1. according to the invention, through the rotary flash evaporation dryer and the gas type rotary roasting furnace, the time required by production is shortened, the energy consumption is saved, the product quality and the yield are improved, and the equipment maintenance cost is reduced.
In the prior art, a static equipment roller kiln is always adopted in the drying and roasting process in order to avoid introducing magnetic impurities due to friction caused by relative motion between a dihydrate ferric phosphate material and equipment. The invention adopts the dynamic equipment rotary kiln, greatly shortens the retention time of the material drying process and improves the drying efficiency. For dynamic equipment, magnetic impurities are easily brought in by friction between materials and the equipment, so that the friction coefficient between the iron phosphate dihydrate material and the wall surface of the rotary kiln is very small by improving the smoothness of a contact part of the equipment and the materials to 0.4 micron, the phenomena of scrap iron and the like caused by stripping of the equipment materials are avoided, the materials are uniformly heated in the dynamic equipment, and the obtained product is uniformly fired.
2. The invention adds the process of rotary flash evaporation and predrying before the high-temperature roasting of the raw materials, and utilizes the residual heat of the gas rotary roasting furnace to predry the moisture in the ferric phosphate dihydrate, so that the heat is fully utilized.
After the dihydrate ferric phosphate material is roasted in the gas roasting furnace, the temperature of hot flue gas at the outlet is still about 500 ℃, and the gas roasting furnace has very high heat. Therefore, the rotary flash evaporation dryer is added in front of the roasting furnace, hot flue gas at the outlet of the roasting furnace is introduced into the rotary flash evaporation dryer, waste heat is used for pre-drying ferric phosphate dihydrate materials, the exhaust gas temperature is reduced, the temperature of gas discharged from the rotary flash evaporation dryer is only about 150 ℃, heat generated by the roasting furnace is fully utilized, the heat utilization rate of the whole system is greatly improved, the energy consumption is reduced, and resources are saved.
Drawings
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
FIG. 1 is a process flow diagram of the present invention.
In the figure: 1-breaking an arch feeding barrel; 2-a feed screw; 3-spin flash dryer; 4-bag dust collector; 5-rotating the discharge valve; 6-combustion-supporting fan; 7-a draught fan; a 8-four-way valve; 9-gas type rotary roasting furnace; 10-cooling section.
Detailed Description
As shown in fig. 1, the system for efficiently and continuously producing anhydrous iron phosphate comprises an arch-breaking feeding barrel 1, a rotary flash dryer 3 and a gas-fired rotary roasting furnace 9.
The bottom of the arch-breaking feeding barrel 1 is provided with a feeding screw 2, and the feeding screw 2 is connected with a rotary flash evaporation dryer 3; the rotary flash dryer 3 is respectively connected with a bag-type dust collector 4 and an emptying pipe; one side of the bag-type dust collector 4 is provided with a compressed nitrogen input pipe, the other side is connected with a tail gas pipe through a draught fan 7, and the bottom of the bag-type dust collector is connected with a gas-type rotary roasting furnace 9 through a rotary discharge valve 5; the top of the gas type rotary roasting furnace 9 is provided with a four-way valve 8 connected with the rotary flash dryer 3, the hearth is respectively connected with a natural gas input pipe and an air input pipe with a combustion-supporting fan 6, and the tail part of the hearth is connected with a cooling section 10; the outer wall of the cooling section 10 is provided with a spray cooling pipe which is respectively connected with a cooling water feeding pipe and a cooling water return pipe; and a ferric phosphate output pipe is arranged at the bottom of one side of the cooling section 10.
Wherein: the smooth finish of the inner wall surface of the gas type rotary roasting furnace 9 is 0.4 micron.
A method for efficiently and continuously producing anhydrous iron phosphate comprises the following steps:
the method comprises the steps that a dihydrate iron phosphate filter cake containing a large amount of free water is conveyed into a feeding screw 2 through an arch breaking feeding barrel 1, the dihydrate iron phosphate filter cake enters a rotary flash drying machine 3 through the feeding screw 2, wet materials are quickly scattered and dried under the combined action of a scattering device and hot air, most of free water in the materials is removed, and pre-dried dihydrate iron phosphate is obtained;
secondly, the pre-dried ferric phosphate dihydrate enters a bag-type dust remover 4 along with tail gas, meanwhile, compressed nitrogen is input into the bag-type dust remover 4, and wet tail gas and the pre-dried ferric phosphate dihydrate after dust removal are respectively obtained after gas-solid separation; the wet tail gas is discharged by a draught fan 7;
thirdly, the pre-dried ferric phosphate after dust removal enters a feed inlet of a gas type rotary roasting furnace 9 through a rotary discharge valve 5, meanwhile, natural gas is input into a hearth of the gas type rotary roasting furnace 9, air is input through a combustion fan 6, high-temperature roasting is carried out at the temperature of 600-800 ℃, residual free water in the materials is evaporated, and water is removed and evaporated in a combined manner, so that the roasted anhydrous ferric phosphate and the heat-exchanged high-temperature flue gas are respectively obtained; the high-temperature flue gas after heat exchange returns to the rotary flash dryer 3 through the four-way valve 8 to pre-dry the high-moisture material;
the roasted anhydrous iron phosphate enters the cooling section 10, and is cooled by spraying cooling water on the outer wall, so that the cooled iron phosphate is obtained.

Claims (3)

1.一种高效连续生产无水磷酸铁的系统，其特征在于：该系统包括破拱喂料桶（1）、旋转闪蒸干燥机（3）和燃气式回转焙烧炉（9）；所述破拱喂料桶（1）的底部设有进料螺旋（2），该进料螺旋（2）与所述旋转闪蒸干燥机（3）相连；所述旋转闪蒸干燥机（3）分别连有布袋除尘器（4）、排空管；所述布袋除尘器（4）的一侧设有压缩氮气输入管，另一侧通过引风机（7）连有尾气管，底部经旋转卸料阀（5）与所述燃气式回转焙烧炉（9）相连；所述燃气式回转焙烧炉（9）的顶部设有与所述旋转闪蒸干燥机（3）相连的四通阀（8），炉膛分别连有天然气输入管和带助燃风机（6）的空气输入管，尾部连有冷却段（10）；所述冷却段（10）的外壁设有喷淋冷却管，该喷淋冷却管分别连有冷却上水管、冷却回水管；所述冷却段（10）的一侧底部设有磷酸铁输出管。1. A system for efficient and continuous production of anhydrous ferric phosphate, characterized in that: the system comprises a broken arch feeding barrel (1), a spin flash dryer (3) and a gas-fired rotary roaster (9); the The bottom of the arch-breaking feeding barrel (1) is provided with a feeding screw (2), and the feeding screw (2) is connected with the rotary flash dryer (3); the rotary flash dryer (3) is respectively A bag filter (4) and an evacuation pipe are connected; one side of the bag filter (4) is provided with a compressed nitrogen input pipe, and the other side is connected with a tail gas pipe through an induced draft fan (7), and the bottom is discharged by rotating The valve (5) is connected with the gas-fired rotary roaster (9); the top of the gas-fired rotary roaster (9) is provided with a four-way valve (8) connected with the spin flash dryer (3) , the furnace chamber is respectively connected with a natural gas input pipe and an air input pipe with a combustion-supporting fan (6), and a cooling section (10) is connected at the tail; the outer wall of the cooling section (10) is provided with a spray cooling pipe, the spray cooling pipe A cooling upper water pipe and a cooling water return pipe are respectively connected; an iron phosphate output pipe is arranged at the bottom of one side of the cooling section (10). 2.如权利要求1所述的一种高效连续生产无水磷酸铁的系统，其特征在于：所述燃气式回转焙烧炉（9）的内壁面光洁度为0.4微米。2 . The high-efficiency and continuous production system for anhydrous ferric phosphate according to claim 1 , wherein the inner wall surface of the gas-fired rotary roasting furnace ( 9 ) has a smoothness of 0.4 microns. 3 . 3.一种高效连续生产无水磷酸铁的方法，包括以下步骤：3. a method for efficient continuous production of anhydrous ferric phosphate, comprising the following steps: ⑴含大量游离水的二水磷酸铁滤饼经破拱喂料桶（1）送到进料螺旋（2）内，通过所述进料螺旋（2）进入旋转闪蒸干燥机（3），得到预干燥后的二水磷酸铁；(1) The iron phosphate dihydrate filter cake containing a large amount of free water is sent to the feeding screw (2) through the arch-breaking feeding barrel (1), and enters the rotary flash dryer (3) through the feeding screw (2), Obtain pre-dried ferric phosphate dihydrate; ⑵所述预干燥后的二水磷酸铁随尾气进入布袋除尘器（4），同时压缩氮气输入至所述布袋除尘器（4），经气固分离后，分别得到含湿尾气和除尘后的预干燥二水磷酸铁；所述含湿尾气经引风机（7）排空；(2) The pre-dried iron phosphate dihydrate enters the bag filter (4) with the tail gas, and at the same time, compressed nitrogen is input to the bag filter (4), and after gas-solid separation, the wet tail gas and the dedusted filter are obtained respectively. Pre-drying iron phosphate dihydrate; the wet exhaust gas is evacuated by the induced draft fan (7); ⑶所述除尘后的预干燥二水磷酸铁经旋转卸料阀（5）进入燃气式回转焙烧炉（9）的进料口，同时天然气输入至所述燃气式回转焙烧炉（9）的炉膛，并通过助燃风机（6）输入空气，在600~800℃的条件下进行高温焙烧，分别得到焙烧后的无水磷酸铁和换热后的高温烟气；所述换热后的高温烟气经四通阀（8）返回所述旋转闪蒸干燥机（3）对高湿份物料进行预干燥；(3) The dedusted pre-dried iron phosphate dihydrate enters the feed port of the gas-fired rotary roaster (9) through the rotary discharge valve (5), and at the same time, natural gas is input into the furnace of the gas-fired rotary roaster (9). , and input air through the combustion-supporting fan (6), and conduct high-temperature roasting under the condition of 600~800 ° C to obtain the roasted anhydrous iron phosphate and the high-temperature flue gas after heat exchange; the high-temperature flue gas after heat exchange is obtained. Return to the rotary flash dryer (3) through the four-way valve (8) to pre-dry the high-moisture material; ⑷所述焙烧后的无水磷酸铁进入冷却段（10），通过外壁喷淋冷却水的方式降温，得到冷却后的磷酸铁。(4) The calcined anhydrous ferric phosphate enters the cooling section (10), and is cooled by spraying cooling water on the outer wall to obtain cooled ferric phosphate.
CN202110018193.3A 2021-01-07 2021-01-07 System and method for efficiently and continuously producing anhydrous iron phosphate Pending CN112707377A (en)

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CN113834321A (en) * 2021-10-22 2021-12-24 山东天力能源股份有限公司 A lithium battery cathode material roasting and cooling system and method
CN114322540A (en) * 2022-02-28 2022-04-12 山东宝阳干燥设备科技有限公司 Special roasting system for lithium iron phosphate reclaimed materials
CN114909874A (en) * 2022-05-07 2022-08-16 天华化工机械及自动化研究设计院有限公司 Method for drying iron phosphate dihydrate by multi-stage venturi cycle superheated steam

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CN114909874A (en) * 2022-05-07 2022-08-16 天华化工机械及自动化研究设计院有限公司 Method for drying iron phosphate dihydrate by multi-stage venturi cycle superheated steam

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