Method for sintering into blocks by using low-grade phosphate rock powder and phosphate rock waste powder

Abstract

The application provides a method for sintering into blocks by using low-grade phosphate rock powder and phosphate rock waste powder. The method comprises the following steps: uniformly mixing the low-grade phosphate rock powder and the phosphate rock waste powder, fuel and sintering waste powder to obtain a mixture; adding water to the mixture to perform balling according to a set balling rate requirement to obtain mixed balls; in a pallet furnace, first laying a thick sintering ore layer from bottom to top, and then laying a mixed ball layer to obtain a laying layer; igniting, sintering, cooling, crushing and screening the laying layer to obtain whole block porous sintered ore; wherein the ignition forms a sintering shell on the surface layer of the mixed balls, and the sintering completely consolidates the mixed balls. The application solves the technical problem that the phosphate rock powder is difficult to be formed into balls without using a binder, and effectively reduces the production cost. The core principle is that the heat generated by the combustion of the quantitatively added coke powder in the formula makes the phosphate rock powder soften, melt and recrystallize, and then the phosphate rock particles are bonded into whole blocks.

Description

Technical Field

[0001] This invention relates to the field of phosphorus chemical industry, and specifically to a method for sintering medium- and low-grade phosphate rock powder and waste phosphate rock powder into briquettes. Background Technology

[0002] my country has the world's second-largest reserves of phosphate rock, but its reserves of high-grade phosphate rock are relatively low. For a long time, the "mining the rich and discarding the poor" mining model has led to a growing scarcity of high-grade phosphate rock resources, forcing phosphate chemical production to gradually reduce the grade of raw phosphate rock. Before the 1990s, the phosphate rock grade (P2O5) used in the electric furnace process for producing yellow phosphorus was generally around 32%, but now the grade of ore used in furnaces only needs to be controlled at around 24% P2O5, and the same applies to phosphate rock used in the production of high-concentration phosphate fertilizers.

[0003] To reduce production costs and improve the utilization rate of phosphate rock resources, enterprises need to increase the comprehensive utilization of low- and medium-grade phosphate rock powder and waste phosphate rock powder. During the washing and beneficiation process of low- and medium-grade phosphate rock, different particle sizes are selected based on the type, origin, and impurity state of the phosphate rock. The resulting washed ore particles are generally too small, failing to meet the 5-35mm particle size requirement for electric furnace yellow phosphorus production. Simultaneously, some existing yellow phosphorus production enterprises generate large amounts of waste phosphate rock powder, which is mostly disposed of through stockpiling, resulting in resource waste. Therefore, adopting low-cost, high-yield, and easy-to-operate processes to form low- and medium-grade washed ore and waste phosphate rock powder to meet the needs of yellow phosphorus production has become a critical technical problem that urgently needs to be solved. The main difficulty lies in the technical feasibility and economic viability of powder agglomeration. Developing a low-cost agglomeration technology for utilizing low- and medium-grade phosphate rock powder and waste phosphate rock powder is of great significance to the phosphate mining, yellow phosphorus, and calcium magnesium phosphate fertilizer production industries.

[0004] Currently, the industry mainly classifies the pelletizing and granulation processes for low- and medium-grade phosphate rock powder and waste phosphate rock powder into two categories. The first category is the phosphate rock powder pelletizing process: phosphate rock powder, coal, and silica are mixed and formulated, a binder is added, and the mixture is pressed into pellets. These pellets are then dried to obtain high-strength pellets, which are directly fed into an electric furnace for reduction smelting. This process relies on various binders to achieve pelletizing, and its main disadvantages are: high binder cost; poor heat resistance of the binder, which easily pulverizes during yellow phosphorus production, failing to provide effective binding; the addition of binder depletes the phosphate rock grade; insufficient binder addition and poor mixing uniformity, resulting in unstable pellet quality and low pelletizing rate; and it is not suitable for pelletizing high-loss-on-ignition phosphate rock powder and subsequent yellow phosphorus production. Therefore, this process is difficult to achieve large-scale industrial application. The second type is the phosphate rock powder disc pelletizing process, also known as the rolling forming process: finely ground phosphate rock powder (120-200 mesh) is mixed with a binder in a certain proportion, wetted with water in a disc pelletizing device, and rolled into shape under the action of mechanical force and capillary force; the green pellets are screened, preheated, and roasted to obtain the finished pellets. Compared with lump ore furnace feed, the pellets obtained by this process have a high removal rate of harmful carbonate impurities, low power consumption, low pollutant emissions, and low production cost. However, its disadvantages are also significant: low production capacity, strict requirements on raw material particle size (more than 80% of the particles must be 200 mesh), and inability to process phosphate rock waste powder with a particle size of 0.1-5mm.

[0005] Therefore, there is an urgent need for a powder ore forming method that does not require the addition of binders, can efficiently utilize medium and low grade phosphate rock powder and phosphate rock waste powder, and is suitable for the production of yellow phosphorus by electric furnace. Summary of the Invention

[0006] The present invention aims to solve the problems of the need to add binders and the inability to efficiently utilize low-grade phosphate rock powder and waste phosphate rock powder in the prior art, and provides a method for sintering low-grade phosphate rock powder and waste phosphate rock powder into blocks.

[0007] The technical method of the present invention is as follows: A method for sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into briquettes includes the following steps: Medium and low grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder are mixed to obtain a mixture. According to the set pelleting rate requirements, water is added to the mixture to form pellets, thus obtaining mixed pellets; In the bogie hearth furnace, a thick sintered ore layer is first laid from bottom to top, followed by a mixed spherical layer to obtain the feed layer; The material layer is ignited, sintered, cooled, crushed, and screened to obtain a whole porous sintered ore; ignition forms a sintered shell on the surface of the mixed spheres, and sintering completely solidifies the mixed spheres.

[0008] Optionally, the composition of the medium- and low-grade phosphate rock powder and phosphate rock waste powder, based on oxides, includes 1%–9% water, 18%–30% silicon dioxide, 20%–30% phosphorus pentoxide, 30%–40% calcium oxide, 0.4%–1.5% ferric oxide, 0.3%–1.5% aluminum oxide, 2%–8% magnesium oxide, and 0.3%–1.1% potassium oxide, with a loss on ignition of 5%–11% and a diameter (D90) less than or equal to 5 mm. Optionally, the fuel includes coke powder and / or pulverized coal.

[0009] Optionally, the composition of the sintering waste powder, based on oxides, includes 0.1%~1% external water, 22%~38% silicon dioxide, 20%~30% phosphorus pentoxide, 35%~40% calcium oxide, 1%~1.5% ferric oxide, 1%~1.5% aluminum oxide, 2%~3% magnesium oxide, and 1%~1.2% potassium oxide, with a loss on ignition of 0.5%~1% and a D90 less than or equal to 5 mm.

[0010] Optionally, the mass ratio of the medium- and low-grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder is 82~97:3~7:10~15.

[0011] Optionally, the set pelleting rate is greater than or equal to 80%, and the mass ratio of water added to the mixture is 92~93:7~8.

[0012] Optionally, the composition of the thick sintered ore, based on oxides, includes 0.1%~1% external water, 22%~38% silicon dioxide, 20%~30% phosphorus pentoxide, 35%~40% calcium oxide, 1%~1.5% ferric oxide, 1%~1.5% alumina, 2%~3% magnesium oxide, and 1%~1.2% potassium oxide, with a loss on ignition of 0.5%~1% and a particle size of 8~20 mm. The thickness of the thick sintered ore layer is 10~20 mm. The thickness of the mixed pellet layer is 600~800 mm.

[0013] Optionally, the ignition step includes: igniting from top to bottom in the bogie furnace, with an ignition temperature of 800~1100℃ and an ignition time of 30~60s.

[0014] Optionally, the sintering step includes: introducing air from top to bottom into the bogie furnace, collecting exhaust gas by exhaust at the lower end of the bogie furnace, and sintering from top to bottom in the bogie furnace; wherein the negative pressure exhaust pressure is 12000~18000Pa, the sintering temperature is 1000~1500℃, and the sintering time is 30~50min.

[0015] The present invention also provides a block of porous sintered ore, which is obtained by the above-described method of sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into blocks.

[0016] The beneficial effects of this invention are: I. This invention solves the technical problem that phosphate rock powder is difficult to spheroidize without the use of binders, effectively reducing production costs. Its core principle is: the coke powder added in a certain amount in the formula generates heat through combustion, causing the phosphate rock powder minerals to undergo softening, melting, and recrystallization reactions, thereby causing the phosphate rock particles to bond together into a whole block. This technology is called "quantitative sintering technology".

[0017] II. In existing technologies, if a non-quantitative sintering process is used, experiments have shown that during sintering in a vertical kiln (vertical roasting furnace), large-area over-firing often results in large sintered bodies, leading to kiln blockage and even kiln stagnation, severely impacting the continuous operation of large-scale industrial production. This invention, through quantitative sintering technology, effectively solves the problems of wall adhesion, kiln blockage, and kiln stagnation during the sintering process in a vertical roasting furnace, ensuring the continuity and stability of production.

[0018] III. This invention provides a method for sintering medium- and low-grade phosphate rock powder or phosphate rock waste powder into briquettes. This method has the following advantages: no binder is required; production is continuous and has a huge capacity, enabling true industrial-scale production, suitable for use with electric furnace yellow phosphorus smelting, and with stable capacity; high degree of automation and easy control, with the entire process of feeding, ignition, ventilation, and cooling controlled by DCS, resulting in strong operational stability; wide applicability of raw materials, capable of processing various phosphate rock powders, phosphate rock dust, phosphate rock waste powder, sintering waste powder, and other powders; uniform sinter quality, with stable temperature field, material layer, and negative pressure, resulting in stable strength, reducibility, and particle size distribution of the finished ore; high thermal efficiency, with the combustion process proceeding from top to bottom, reasonable heat utilization, and the ability to be equipped with a waste heat recovery system; mature technology and reliable equipment operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the method of sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into blocks according to the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a method for sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into briquettes, such as... Figure 1 As shown, it includes the following steps: S1. Mix low-grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder to obtain a mixture.

[0022] In this embodiment, the composition of the low-grade phosphate rock powder and waste phosphate rock powder, based on oxides, includes 1%~9% external water, 18%~30% silicon dioxide, 20%~30% phosphorus pentoxide, 30%~40% calcium oxide, 0.4%~1.5% ferric oxide, 0.3%~1.5% aluminum oxide, 2%~8% magnesium oxide, and 0.3%~1.1% potassium oxide, with a loss on ignition of 5%~11% and a D90 (particle size corresponding to a cumulative distribution of 90%) less than or equal to 5 mm. The low-grade phosphate rock powder and waste phosphate rock powder of this invention may also include trace impurities and internal water. These trace impurities are too low in content to be detected by the aforementioned testing instruments, and their presence does not affect the implementation of the method of this invention or the technical effect of the obtained sintered block.

[0023] For example, the composition of phosphate rock waste powder is shown in Table 1.

[0024] Table 1 For example, the composition of medium- and low-grade phosphate rock powder is shown in Table 2.

[0025] Table 2 In this invention, low-grade phosphate rock powder and phosphate rock waste powder are used as the main raw materials, which enable them to be sintered into blocks, reduce loss on ignition, and improve the P2O5 grade.

[0026] In this embodiment, the fuel includes coke powder and / or coal powder.

[0027] In this embodiment, the composition of the sintering waste powder, based on oxides, includes 0.1%~1% external water, 22%~38% silicon dioxide, 20%~30% phosphorus pentoxide, 35%~40% calcium oxide, 1%~1.5% ferric oxide, 1%~1.5% aluminum oxide, 2%~3% magnesium oxide, and 1%~1.2% potassium oxide, with a loss on ignition of 0.5%~1% and a D90 less than or equal to 5 mm.

[0028] For example, the composition of the sintering waste powder is shown in Table 3. The sintering waste powder of the present invention may also include trace impurities and its internal water. The trace impurities are not detected by the above-mentioned detection instruments because their content is too low, and their presence does not affect the implementation of the method of the present invention or the technical effect of the obtained sintered block.

[0029] Table 3 The sintering waste powder of this invention is actually mineral powder with unqualified particle size (less than or equal to 5mm) generated during the crushing and screening process of the product (after sintering in step S4). The purpose of adding it is to treat unqualified products in the production process.

[0030] In this embodiment, the mass ratio of medium- and low-grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder is 82~97:3~7:10~15.

[0031] In this embodiment, before step S1, the process further includes: crushing and screening low- and medium-grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder. Here, particles larger than 5mm enter the finished product silo, while particles smaller than or equal to 5mm are returned for sintering, i.e., returned ore.

[0032] S2. According to the set pelleting rate requirements, water is added to the mixture to granulate it, resulting in mixed pellets. The mixed pellets are small particles of 1-3 mm.

[0033] In this embodiment, the set ball formation rate is greater than or equal to 70% to ensure air permeability. For example, the ball formation rate is 80% or 90%.

[0034] During the granulation process, the water ratio depends on the moisture content of the raw materials.

[0035] S3. In the bogie furnace, a thick sintered ore layer is first laid from bottom to top, followed by a mixed ball layer to obtain the material layer.

[0036] In this embodiment, the thick sintered ore is actually a portion of the qualified product with a particle size of 8-20mm selected after sintering in step S4 during the crushing and screening process, which is used as the bottom material for the bogie hearth furnace. The composition of the thick sintered ore, based on oxides, includes 0.1%-1% external water, 22%-38% silicon dioxide, 20%-30% phosphorus pentoxide, 35%-40% calcium oxide, 1%-1.5% ferric oxide, 1%-1.5% aluminum oxide, 2%-3% magnesium oxide, and 1%-1.2% potassium oxide, with a loss on ignition of 0.5%-1% and a particle size of 8-20mm.

[0037] For example, the composition of the thick sinter is shown in Table 4. The thick sinter of the present invention may also include trace impurities and internal water. The trace impurities are not detected by the above-mentioned detection instruments because their content is too low, and their presence does not affect the implementation of the method of the present invention or the technical effect of the obtained sintered block.

[0038] Table 4 The sintering waste powder and thick sintered ore of this invention have the same composition, the only difference being the particle size.

[0039] In this embodiment, the thickness of the thick sintered ore layer is 10-20 mm to protect the grate bars of the trolley. For example, the thickness is 12 mm, 15 mm, or 17 mm.

[0040] In this embodiment, the thickness of the mixed spherical material layer is 600~800mm. For example, the thickness is 650mm, 700mm, or 750mm.

[0041] S4. The material layer is ignited, sintered, cooled, crushed, and screened to obtain a solid porous sintered ore. Ignition forms a sintered shell on the surface of the mixed spheres, and sintering completely solidifies the mixed spheres. Air cooling is used for cooling. Sintering is divided into a sintering section and a cooling section, and the heated air from the cooling section is transported to the sintering section for waste heat utilization. Particles larger than 5mm after crushing and screening are considered products, while products ≤5mm are unqualified products and are added as sintered ore.

[0042] In this embodiment, the ignition step includes: igniting from top to bottom in a bogie furnace, with an ignition temperature of 800~1100℃ and an ignition time of 30~60s, only burning the surface layer to form a sintered shell.

[0043] In this embodiment, the sintering step includes: introducing air from top to bottom into the bogie furnace, collecting exhaust gas by exhaust at the bottom of the bogie furnace, and sintering from top to bottom in the bogie furnace; wherein, the pressure of the negative pressure exhaust is 12000~18000Pa, the sintering temperature is 1000~1500℃, and the sintering time is 30~50min.

[0044] Specifically, the bogie furnace moves forward, negative pressure ventilation (12000–18000 Pa) is applied, and the combustion wave moves downward; consolidation is completed at 1300–1500℃ for 30–50 minutes. This invention utilizes a unique formula and sintering method: the material layer is placed on the bogie, ignited, ventilated, and combusted from top to bottom, allowing the combustion layer to slowly advance from top to bottom, sintering the material layer into a single porous sintered ore. Four layers exist simultaneously from top to bottom within the material layer: (1) Sintered ore layer (sintered layer): Located at the top of the paving layer, it is a sintered and cooled ore layer. The downward air is preheated when passing through this layer, which not only provides preheated air for the combustion of the lower layer, but also protects the combustion zone of the lower layer.

[0045] (2) Combustion layer (core reaction zone): The core area of ​​sintering, where the temperature is maintained at 1000-1100℃. Here, the coke is fully combusted and releases heat, the minerals soften, melt and recrystallize, and the particles bond together to form an integral block structure, completing the core sintering reaction.

[0046] (3) Preheating layer: High-temperature exhaust gas passes through this layer from top to bottom, heating the mixing ball to the critical ignition temperature; at the same time, it completes the preheating and pretreatment reactions such as evaporation of moisture in the raw materials and decomposition of carbonates. Here, the high-temperature exhaust gas is the air after combustion.

[0047] In phosphate rock, carbonates mainly exist in the form of calcite (CaCO3) or dolomite (CaCO3·MgCO3). The decomposition temperature of carbonates is between 700 and 1000℃. The CO2 released from the decomposition is immediately reduced to CO by carbon dioxide (C) or reacts with phosphorus to form lower oxides. This is known as loss on ignition (LOI). A high LOI means a high amount of CO2 is released from the decomposition, so CO2 is also used to represent LOI. Practical experience shows that the decomposition rate of carbonate-containing phosphate rock is over 82% at 700–1000℃, and the reaction temperature in the furnace can reach as high as 1400℃, so the decomposition rate of carbonates can be considered 100%. For every 1% increase in CO2 in phosphate rock, the power consumption increases by 200 kWh, coke consumption by 30 kg, and phosphorus mud production by 10%–20% per ton of yellow phosphorus. Furthermore, the oxidation reaction of CO2 with the electrodes at 700–900℃ also increases electrode consumption.

[0048] (4) Cold material layer / wet material layer: The unreacted thick sintered ore at the bottom of the material layer, where the high-temperature waste gas is further cooled and finally extracted by the exhaust fan to complete the airflow circulation.

[0049] The principle of dynamic sintering process: Ignition is carried out only on the surface of the material layer, and the exhaust fan under the trolley continuously draws air to form an airflow channel from top to bottom: air enters the material layer from top to bottom, providing oxygen for coke combustion. The coke combustion releases a large amount of heat, which pushes the combustion layer to move slowly from top to bottom until the material layer is completely burned through, and the entire sintering process is completed.

[0050] In addition, this invention utilizes a loader to load low- and medium-grade phosphate rock powder, phosphate rock waste powder, and fuel into the raw material silo. The low- and medium-grade phosphate rock powder, phosphate rock waste powder, fuel, sintering waste powder, and other raw materials are metered via belt feeders and fed into a mixing drum (along with the screened return material) for mixing with water and granulation. The mixed raw materials are then fed into a sintering machine (which includes a material distribution system, a bogie furnace, etc.; the material distribution includes a thick sintered ore layer and a mixed pellet layer). The mixed pellets are solidified (also known as sintering) into lumps in the bogie furnace, then crushed by a crusher and screened by a hot ore screen. The lumps that meet the requirements are sent to the finished product silo, while the unqualified ore powder is returned to the mixing drum and sintering machine for secondary solidification.

[0051] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0052] The present invention will be described in detail below through embodiments and experimental examples. However, these are merely examples and do not limit the present invention in any way.

[0053] Example 1 This embodiment provides a method for sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into briquettes, including the following steps: Step 1: Mix low-to-medium grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder in a mass ratio of 85:6:15 to obtain a mixture. The composition of the low-to-medium grade phosphate rock powder and phosphate rock waste powder is shown in Table 5. The fuel is pulverized coal. The composition of the sintering waste powder is shown in Table 6. The mixing time is 0.5 hours.

[0054] Table 5 Table 6 Step 2: Based on the set pelleting rate of 80%, water is added to the mixture to form pellets, and mixed pellets are obtained. The mass ratio of the mixture to water is 93:7.

[0055] Step 3: In the bogie furnace, first lay a thick sintered ore layer from bottom to top, then lay a mixed ball layer to obtain the material layer; the thickness of the thick sintered ore layer is 20mm (as shown in Table 6, only the particle size is different, the particle size of the thick sintered ore is 10mm), and the thickness of the mixed ball layer is 700mm. Step 4: Ignite, sinter, cool, crush, and screen the material layer to obtain a whole porous sintered ore. The ignition and sintering process includes: igniting from top to bottom in a bogie furnace, introducing air from top to bottom, and drawing out exhaust gas from bottom with an exhaust fan at a pressure of 12000 Pa. The ignition temperature is 800℃ and the ignition time is 60s. Ignition forms a sintered shell on the surface of the mixed spheres. Then, it is sintered at 1100℃ for 45 minutes, followed by cooling, crushing, and screening.

[0056] Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into briquettes, characterized in that, Includes the following steps: Medium and low grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder are mixed to obtain a mixture. According to the set pelleting rate requirements, water is added to the mixture to form pellets, thus obtaining mixed pellets; In the bogie hearth furnace, a thick sintered ore layer is first laid from bottom to top, followed by a mixed spherical layer to obtain the feed layer; The material layer is ignited, sintered, cooled, crushed, and screened to obtain a whole porous sintered ore; ignition forms a sintered shell on the surface of the mixed spheres, and sintering completely solidifies the mixed spheres.

2. The method according to claim 1, characterized in that, The composition of the medium- and low-grade phosphate rock powder and phosphate rock waste powder, calculated by oxides, includes 1% to 9% external water, 18% to 30% silicon dioxide, 20% to 30% phosphorus pentoxide, 30% to 40% calcium oxide, 0.4% to 1.5% ferric oxide, 0.3% to 1.5% aluminum oxide, 2% to 8% magnesium oxide, and 0.3% to 1.1% potassium oxide, with a loss on ignition of 5% to 11% and a D90 less than or equal to 5 mm.

3. The method according to claim 1, characterized in that, The fuel includes coke powder and / or coal powder.

4. The method according to claim 1, characterized in that, The composition of the sintering waste powder, calculated by oxides, includes 0.1%~1% external water, 22%~38% silicon dioxide, 20%~30% phosphorus pentoxide, 35%~40% calcium oxide, 1%~1.5% ferric oxide, 1%~1.5% aluminum oxide, 2%~3% magnesium oxide, and 1%~1.2% potassium oxide, with a loss on ignition of 0.5%~1% and a D90 less than or equal to 5 mm.

5. The method according to claim 1, characterized in that, The mass ratio of the medium- and low-grade phosphate rock powder, phosphate rock waste powder, fuel, and sintering waste powder is 82~97:3~7:10~15.

6. The method according to claim 1, characterized in that, The set ball formation rate is greater than or equal to 80%.

7. The method according to claim 1, characterized in that, The composition of the thick sintered ore, based on oxides, includes 0.1%~1% external water, 22%~38% silicon dioxide, 20%~30% phosphorus pentoxide, 35%~40% calcium oxide, 1%~1.5% ferric oxide, 1%~1.5% aluminum oxide, 2%~3% magnesium oxide, and 1%~1.2% potassium oxide, with a loss on ignition of 0.5%~1% and a particle size of 8~20mm. The thickness of the thick sintered ore layer is 10~20mm. The thickness of the mixed ball material layer is 600~800mm.

8. The method according to claim 1, characterized in that, The ignition step includes: In the bogie furnace, ignition is performed from top to bottom at a temperature of 800~1100℃ for 30~60 seconds.

9. The method according to claim 1, characterized in that, The sintering step includes: Air is introduced from top to bottom into the bogie hearth furnace, and exhaust gas is collected by exhaust at the bottom of the bogie hearth furnace. Sintering is then carried out from top to bottom in the bogie hearth furnace. The negative pressure exhaust pressure is 12000~18000Pa, the sintering temperature is 1000~1500℃, and the sintering time is 30~50min.

10. A monolithic porous sintered ore, characterized in that, The solid porous sintered ore is obtained by the method described in any one of claims 1-9, which involves sintering medium- and low-grade phosphate rock powder and phosphate rock waste powder into blocks.

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