Method for preparing phosphorus pentoxide by utilizing phosphorus-containing material
By mixing phosphate rock and lithium iron phosphate battery waste with carbonaceous reducing agents and silica, and carrying out molten reduction and oxidation reactions, the problem of efficiently preparing phosphorus pentoxide from phosphate rock and lithium iron phosphate battery waste has been solved, realizing efficient resource utilization and environmentally friendly treatment.
Patent Information
- Application Number
- CN202511438965.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-10
- Publication Date
- 2025-11-07
AI Technical Summary
In the existing technology, there are few reports on schemes that use phosphate rock and lithium iron phosphate battery waste as phosphorus sources to prepare phosphorus pentoxide, which leads to resource waste and environmental risks. Moreover, the existing methods have high energy consumption and high melting point, requiring strict environmental protection treatment.
After pretreatment, phosphate rock and lithium iron phosphate battery waste are mixed with carbonaceous reducing agent and silica to carry out a molten reduction reaction to generate phosphorus-containing vapor. Subsequently, under an oxidizing atmosphere, it is converted into phosphorus pentoxide. The lithium iron phosphate battery waste is used to lower the melting point and fix fluorine to generate calcium fluoride, thus avoiding the generation of harmful gases.
It reduces the energy consumption in phosphorus pentoxide preparation, improves the utilization rate of phosphorus, realizes efficient recovery and harmless treatment of phosphorus resources, and reduces the yield of phosphorus iron and the burden of environmental treatment.
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of phosphorus chemical industry, and particularly relates to a method for preparing phosphorus pentoxide by using phosphorus-containing materials. BACKGROUND
[0002] The method for preparing phosphorus pentoxide from phosphate ore is a large-scale industrial production "thermal process", the core of which is to extract and oxidize elemental phosphorus from phosphate ore through high-temperature chemical reaction. This method uses fluorapatite-containing phosphate ore as raw material, and coke and silica (quartz sand) as reducing agent and fluxing agent, which are mixed and then sent into a sealed electric arc furnace. Under the electric arc heating of up to 1500℃, the key thermal reduction reaction occurs in the furnace: the calcium phosphate in the phosphate ore is reduced by the carbon in the coke to generate phosphorus vapor (P4) and carbon monoxide, while the silica combines with the byproduct calcium oxide to form molten calcium silicate slag, which is periodically discharged from the bottom of the furnace, thereby ensuring the continuous progress of the reaction. The generated mixed gas (mainly containing phosphorus vapor and CO) is guided out of the electric furnace, mixed with excess air and combusted vigorously, the phosphorus vapor is oxidized into phosphorus pentoxide powder, and a large amount of heat is released. The advantages of this method are mature technology, large production capacity, and it is the mainstream method for producing pure phosphorus pentoxide and its downstream products (such as thermal process phosphoric acid) in industry, but the disadvantages are high energy consumption, high melting point, high heating temperature (often greater than 1500℃), and a large amount of slag and waste gas are generated, which requires strict environmental protection treatment facilities.
[0003] Phosphorus elements are also contained in lithium iron phosphate batteries, which can also be used as raw materials for the preparation of phosphorus pentoxide. At present, the recovery of retired lithium iron phosphate battery positive materials mainly relies on hydrometallurgical process, which extracts valuable metal elements through full-component leaching or selective leaching. Since the phosphorus and iron in the positive material have low inherent value, and the aluminum, copper and other impurities in the residue produced after lithium extraction are difficult to completely remove, the existing recovery process often focuses on extracting lithium with higher economic value. This leads to a large amount of phosphorus and iron-containing phosphorus iron slag being stored in the form of solid waste, not only occupying land resources, but also posing environmental risks. At the same time, this kind of urban mineral resources rich in phosphorus and iron cannot be efficiently utilized, resulting in significant resource waste. Although there are explorations of using raw materials from waste lithium iron phosphate batteries to prepare phosphorus pentoxide, the technology is not mature, and waste lithium iron phosphate batteries contain fluorine, which can easily generate toxic and harmful gases, causing harm to equipment and the environment.
[0004] At present, there are few reports on a method for preparing phosphorus pentoxide by simultaneously using phosphate ore and waste lithium iron phosphate battery materials as phosphorus sources. Therefore, how to provide a method for preparing phosphorus pentoxide by simultaneously using phosphate ore and waste lithium iron phosphate battery materials, utilizing the synergistic effect of different raw materials to reduce the melting point of phosphate ore, reduce the preparation cost of phosphorus pentoxide, and at the same time complete the recovery and treatment of waste lithium iron phosphate battery materials is a difficult problem to be solved in the field. SUMMARY
[0005] Therefore, the application provides a method for preparing phosphorus pentoxide by using phosphorus-containing materials to solve the problem that there are few reports on the preparation of phosphorus pentoxide by using phosphorite and lithium iron phosphate battery waste as phosphorus sources.
[0006] To achieve the above-mentioned purpose, the application adopts the following technical scheme: The application provides a method for preparing phosphorus pentoxide by using phosphorus-containing materials, which comprises the following steps: 1) Preprocessing the phosphorus-containing materials to obtain phosphorus-containing material particles; The phosphorus-containing materials comprise phosphorite and lithium iron phosphate battery waste. 2) Mixing the phosphorus-containing material particles with carbonaceous reducing agents and silica to obtain a mixture; 3) Performing a smelting reduction reaction on the mixture to obtain a phosphorus-containing vapor gas phase and a liquid phase, wherein the liquid phase comprises an upper layer and a lower layer; the upper layer contains silicate slag, and the lower layer contains phosphorus iron; 4) Mixing the phosphorus-containing vapor gas phase with an oxidizing atmosphere to perform an oxidation reaction to obtain phosphorus pentoxide.
[0007] Preferably, the mass ratio of the phosphorite to the lithium iron phosphate battery waste in the phosphorus-containing materials is 100:20-40. The P2O5 content in the phosphorite is 20-30%.
[0008] Preferably, the preprocessing of the phosphorite comprises sequentially performing crushing, grinding, and drying, and the particle size of the preprocessed phosphorite is 100-160 μm. The lithium iron phosphate battery waste is lithium iron phosphate battery black powder, and the preprocessing of the lithium iron phosphate battery waste comprises sequentially performing roasting and impurity removal and crushing. The roasting temperature is 600-750°C, and the roasting time is 30-60 min. The particle size of the preprocessed lithium iron phosphate battery waste is 60-90 μm.
[0009] Preferably, the addition amount of the carbonaceous reducing agent is 105-110% of the theoretical reduction addition amount. The addition amount of the silica is such that the CaO / SiO2 in the mixture system is 0.9-1.1.
[0010] Preferably, the carbonaceous reducing agent comprises coke and / or anthracite.
[0011] Preferably, the temperature of the smelting reduction reaction in step 3) is 1200-1450°C.
[0012] Preferably, the oxidizing atmosphere in step 4) comprises dry air.
[0013] Compared with the prior art, the application has the following beneficial effects: 1. The application uses phosphorite and lithium iron phosphate battery waste as phosphorus-containing materials to prepare phosphorus pentoxide, and in the reduction reaction process, Li2O and Fe2O3 are generated in the lithium iron phosphate battery waste, which can reduce the melting point and viscosity of the phosphorite reaction system, promote the reduction reaction of phosphorus, reduce energy consumption, and the lithium iron phosphate battery waste plays a dual role of fluxing and providing a phosphorus source; the calcium element in the phosphorite can also fix the fluorine in the lithium iron phosphate battery waste to generate calcium fluoride, avoiding the generation of harmful fluorine-containing gas.
[0014] 2. The application can maximize the use of phosphorus in phosphorite and lithium iron phosphate battery waste to generate phosphorus pentoxide, improve the value of phosphorus, reduce the yield of phosphorus iron, and avoid the problem of frequent discharge of phosphorus iron in the process.
[0015] 3. The application simultaneously uses phosphorite and secondary resources, conforms to the concept of circular economy, and realizes harmless treatment of toxic battery waste, having high economic benefits. DETAILED DESCRIPTION
[0016] The application provides a method for preparing phosphorus pentoxide by using phosphorus-containing materials, comprising the following steps: 1. Pre-treating the phosphorus-containing materials to obtain phosphorus-containing material particles; 2. Mixing the phosphorus-containing material particles with a carbonaceous reducing agent and silica to obtain a mixture; 3. Performing a smelting reduction reaction on the mixture to obtain a phosphorus-containing vapor gas phase and a liquid phase, wherein the liquid phase comprises an upper layer and a lower layer; the upper layer contains silicate slag, and the lower layer contains phosphorus iron; 4. Mixing the phosphorus-containing vapor gas phase with an oxidizing atmosphere to perform an oxidation reaction to obtain phosphorus pentoxide.
[0017] In the application, the phosphorus-containing materials comprise phosphorite and lithium iron phosphate battery waste; In the application, the mass ratio of phosphorite to lithium iron phosphate battery waste in the phosphorus-containing materials is 100:20-40, preferably 100:25-35, and further preferably 100:30; if the addition amount of lithium iron phosphate battery waste is less than the limit value, the synergistic effect will decrease and the fluxing effect will not be effective; if the addition amount is greater than the limit value, a large amount of phosphorus iron will be generated, increasing the process burden and reducing the yield of phosphorus pentoxide.
[0018] In the application, the P2O5 content in the phosphorite is 20-30%, and can be 22%, 24%, 25%, 26%, or 28%.
[0019] In the present application, the pretreatment of the phosphate ore includes crushing, grinding and drying in sequence, and the particle size of the pretreated phosphate ore is 100-160 μm, and specifically can be 110 μm, 120 μm, 130 μm, 140 μm, 150 μm.
[0020] In the present application, the lithium iron phosphate battery waste is lithium iron phosphate battery black powder (positive electrode material), and the pretreatment of the lithium iron phosphate battery waste includes roasting and impurity removal and crushing in sequence.
[0021] In the present application, the temperature of the roasting and impurity removal is 600-750 ℃, and specifically can be 620 ℃, 640 ℃, 650 ℃, 660 ℃, 680 ℃, 700 ℃, 720 ℃, 740 ℃; the time is 30-60 min, and specifically can be 35 min, 40 min, 45 min, 50 min, 55 min; the roasting and impurity removal can remove impurities, avoiding the influence of impurities on the preparation of P2O5.
[0022] In the present application, the particle size of the pretreated lithium iron phosphate battery waste is 60-90 μm, and specifically can be 65 μm, 70 μm, 75 μm, 80 μm, 85 μm.
[0023] In the present application, the addition amount of the carbonaceous reducing agent is 105-110% of the theoretical reduction addition amount, and specifically can be 106%, 107%, 108%, 109%; the theoretical reduction addition amount is the amount of reducing P2O5 and Fe2O3 to obtain the corresponding elements.
[0024] In the present application, the addition amount of the silica is such that the CaO / SiO2 in the batch system is 0.9-1.1, and specifically can be 0.92, 0.95, 0.98, 1, 1.02, 1.05, 1.08.
[0025] In the present application, the carbonaceous reducing agent includes coke and / or anthracite.
[0026] In the present application, the temperature of the melting reduction reaction in step 3) is 1200-1450 ℃, and specifically can be 1220 ℃, 1250 ℃, 1280 ℃, 1300 ℃, 1320 ℃, 1350 ℃, 1380 ℃, 1400 ℃.
[0027] In the present application, the oxidation atmosphere in step 4) includes dry air.
[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0029] Embodiment 1
[0030] The lithium iron phosphate battery black powder (P2O5: 42.88%) is heated to 650°C for 40 minutes for impurity removal treatment, and then is crushed to a particle size of 60-80 μm for standby; the phosphate rock (P2O5: 25%) is crushed and ground to obtain a powder with a particle size of 120-140 μm, and then is dried to a moisture content of <1% to avoid heat consumption and splashing.
[0031] The treated phosphate rock and lithium iron phosphate battery black powder are mixed in a mass ratio of 100:30 to serve as phosphorus-containing material particles; then coke and silica (the addition amount of the carbonaceous reducing agent is 105% of the theoretical value, and the addition amount of the silica is CaO / SiO2=1) are sequentially added to the phosphorus-containing material particles, and a double-helix conical mixer is used for mixing for 20 minutes to complete the batching.
[0032] The furnace temperature is set to 1250°C, and the mixture is continuously fed, and a melting reduction reaction occurs in the furnace to obtain a gas phase and a liquid phase; the gas phase contains phosphorus vapor and carbon monoxide and the like, and the gas phase is reacted with excess air to completely oxidize P4 to P2O5, and then a cyclone separator is used to separate P2O5; the heat in the oxidation process is reused to heat the phosphorus-containing vapor. The liquid phase contains high-density phosphorus iron and low-density silicate slag (containing lithium, calcium fluoride, etc.), and the phosphorus iron and the silicate slag are separated by using the density difference, and the phosphorus iron can be used as an alloy additive; the silicate slag can be further used for lithium extraction.
[0033] It is detected that the silicate slag basically does not contain phosphorus, and the phosphorus is converted into phosphorus iron and P2O5, and the phosphorus in the P2O5 accounts for 95.65% of the total amount.
[0034] Embodiment 2
[0035] The lithium iron phosphate battery black powder (P2O5: 42.88%) is heated to 750°C for 30 minutes for impurity removal treatment, and then is crushed to a particle size of 60-90 μm for standby; the phosphate rock (P2O5: 30%) is crushed and ground to obtain a powder with a particle size of 120-160 μm, and then is dried to a moisture content of <1% to avoid heat consumption and splashing.
[0036] The treated phosphate ore and lithium iron phosphate battery black powder are mixed in a mass ratio of 100:20 to serve as phosphorus-containing material particles; then coke and silica are sequentially added to the phosphorus-containing material particles (the addition amount of the carbonaceous reducing agent is 105% of the theoretical value, and the addition amount of the silica is CaO / SiO2=1), and a double-helix conical mixer is used to mix for 30 min to complete the batching.
[0037] The furnace temperature is set to 1300°C, the batch material is continuously fed, and a smelting reduction reaction occurs in the furnace to obtain gas phase and liquid phase; the gas phase contains phosphorus vapor and carbon monoxide and the like, and the gas phase is reacted with excess air to completely oxidize P4 to P2O5, and then a cyclone separator is used to separate P2O5; the heat generated in the oxidation process is recycled to heat the phosphorus-containing vapor. The liquid phase contains high-density phosphorus iron and low-density silicate slag (containing lithium, calcium fluoride, etc.), and the phosphorus iron and the silicate slag are separated by using the difference in density, and the phosphorus iron can be used as an alloy additive; the silicate slag can be further used to extract lithium.
[0038] It is detected that the silicate slag contains substantially no phosphorus, and the phosphorus is converted into phosphorus iron and P2O5, and the phosphorus accounts for 95.91% of the total amount in the P2O5.
[0039] Example 3
[0040] The lithium iron phosphate battery black powder (P2O5: 42.88%) is heated to 600°C for 60 min for impurity removal treatment, and then is crushed to a particle size of 80-90 μm for standby; the phosphate ore (P2O5: 22%) is crushed and ground to obtain a powder with a particle size of 100-130 μm, and then is dried to a moisture content of <1% to avoid heat consumption and splashing.
[0041] The treated phosphate ore and lithium iron phosphate battery black powder are mixed in a mass ratio of 100:35 to serve as phosphorus-containing material particles; then coke and silica are sequentially added to the phosphorus-containing material particles (the addition amount of the carbonaceous reducing agent is 110% of the theoretical value, and the addition amount of the silica is CaO / SiO2=1.1), and a double-helix conical mixer is used to mix for 20 min to complete the batching.
[0042] The furnace temperature is set to 1200°C, the batch material is continuously fed, and a smelting reduction reaction occurs in the furnace to obtain gas phase and liquid phase; the gas phase contains phosphorus vapor and carbon monoxide and the like, and the gas phase is reacted with excess air to completely oxidize P4 to P2O5, and then a cyclone separator is used to separate P2O5; the heat generated in the oxidation process is recycled to heat the phosphorus-containing vapor. The liquid phase contains high-density phosphorus iron and low-density silicate slag (containing lithium, calcium fluoride, etc.), and the phosphorus iron and the silicate slag are separated by using the difference in density, and the phosphorus iron can be used as an alloy additive; the silicate slag can be further used to extract lithium.
[0043] The detected silicate slag contains no phosphorus, and the phosphorus is converted into phosphorus iron and phosphorus pentoxide, and the phosphorus in the phosphorus pentoxide accounts for 93.12% of the total amount.
[0044] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.
[0045] The above description of disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for producing phosphorus pentoxide by using a phosphorus-containing material, characterized by, The method comprises the following steps: 1) pretreating the phosphorus-containing material to obtain phosphorus-containing material particles; The phosphorus-containing material comprises phosphate rock and lithium iron phosphate battery waste; 2) mixing the phosphorus-containing material particles with carbonaceous reducing agent and silica to obtain a mixture; 3) performing a smelting reduction reaction on the mixture to obtain a phosphorus-containing vapor gas phase and a liquid phase, the liquid phase comprising an upper layer and a lower layer; the upper layer contains silicate slag, and the lower layer contains phosphorus iron; 4) mixing the phosphorus-containing vapor gas phase with an oxidizing atmosphere to perform an oxidation reaction to obtain phosphorus pentoxide.
2. The method for preparing phosphorus pentoxide using a phosphorus-containing material according to claim 1, characterized by, The mass ratio of the phosphate rock to the lithium iron phosphate battery waste in the phosphorus-containing material is 100:20-40; The P2O5 content in the phosphate rock is 20-30%.
3. The method of claim 2, wherein the phosphorus-containing material is phosphorus pentoxide. The pretreatment of the phosphate rock comprises crushing, grinding, and drying in sequence, and the particle size of the pretreated phosphate rock is 100-160 μm; The lithium iron phosphate battery waste is lithium iron phosphate battery black powder, and the pretreatment of the lithium iron phosphate battery waste comprises roasting and impurity removal and crushing in sequence; The roasting temperature is 600-750 °C, and the time is 30-60 min; The particle size of the pretreated lithium iron phosphate battery waste is 60-90 μm.
4. The method for preparing phosphorus pentoxide by using phosphorus-containing material according to any one of claims 1-3, characterized in that, The addition amount of the carbonaceous reducing agent is 105-110% of the theoretical reduction addition amount; The addition amount of the silica is such that the CaO / SiO2 in the mixture system is 0.9-1.
1.
5. The method of claim 4, wherein the phosphorus-containing material is phosphorus pentoxide. The carbonaceous reducing agent comprises coke and / or anthracite.
6. The method of claim 5, wherein the phosphorus-containing material is phosphorus pentoxide. The temperature of the smelting reduction reaction in step 3) is 1200-1450 °C.
7. The method for producing phosphorus pentoxide using a phosphorus-containing material according to claim 5 or 6, characterized by, The oxidizing atmosphere in step 4) comprises dry air.