Method for reducing sesquioxide of phosphorite by chemical beneficiation method and phosphate concentrate thereof

Abstract

The invention relates to the technical field of phosphate concentrate, in particular to a method for reducing sesquioxide of phosphorite through a chemical beneficiation method and phosphate concentrate thereof. The invention discloses a method for reducing sesquioxide of phosphorite through a chemical beneficiation method. The method comprises the following steps that raw ore is obtained; the raw ore is subjected to calcination treatment, and calcined ore is obtained; dispersing the calcined ore in a solvent, adding a phosphorus inhibitor, and fully mixing; then a nitric acid solution is added for leaching treatment, and leached ore is obtained; after the leaching treatment is finished, filtering and washing the leached ore to obtain phosphate concentrate; according to the method disclosed by the invention, the phosphorus concentrate with the total amount of the iron and aluminum impurities lower than 0.8% can be obtained after the phosphorus raw ore with the total amount of the iron and aluminum impurities larger than 2.5% is calcined and subjected to primary leaching in the nitric acid solution with the mass concentration of 20-25% at the temperature of 45-50 DEG C for 3-4 h; meanwhile, by adding the acidolysis inhibitor, dissolution of P can be obviously inhibited, and the grade of phosphate concentrate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of phosphate concentrates, in particular to a method for reducing sesquioxides in phosphate ore by a chemical beneficiation method and the phosphate concentrate. Background Art

[0002] It is found that the current phosphate ore has a high content of iron and aluminum impurities, and the total content of iron and aluminum impurities reaches more than 1.5%. When physical mineral processing is used, the iron and aluminum impurities in the phosphate ore cannot be effectively reduced, resulting in excessive iron and aluminum impurities in the phosphate concentrate, which affects the use of the phosphate concentrate.

[0003] The inventors have discovered that in current chemical mineral processing, when nitric acid is used to leach phosphate ore, it is found that when the concentration of nitric acid reaches 35% or more, some iron and aluminum impurities in the phosphate ore can be removed, but at the same time, P in the phosphate ore is also obviously leached out, resulting in a significant decrease in the P content in the phosphate concentrate and no improvement in the grade; and when the concentration of nitric acid is lower than 10%, the amount of iron and aluminum impurities removed from the phosphate ore during leaching is very small, and the total amount of iron and aluminum impurities in the phosphate concentrate is still maintained at a relatively high level (>1.2%), which fails to achieve the effect of reducing the iron and aluminum impurities in the phosphate concentrate.

[0004] To this end, the present application provides a method for reducing sesquioxides in phosphate ore by chemical beneficiation and its phosphate concentrate. Summary of the invention

[0005] The present application provides a method for reducing sesquioxides in phosphate ore by a chemical beneficiation method, wherein phosphate ore with a total amount of iron and aluminum impurities greater than 2.5% can be calcined and once leached with a nitric acid solution with a mass concentration of 20-25% at 45-50° C. and for 3-4 hours to obtain a phosphate concentrate with a total amount of iron and aluminum impurities less than 0.8%; at the same time, by adding an acidolysis inhibitor, the dissolution of P can be significantly inhibited, thereby improving the grade of the phosphate concentrate.

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

[0007] In a first aspect, the present application provides a method for reducing sesquioxides in phosphate rock by a chemical beneficiation method, comprising the following steps:

[0008] Obtaining raw ore;

[0009] calcining the raw ore to obtain calcined ore;

[0010] The calcined ore is dispersed in a solvent, a phosphorus inhibitor is added, and the mixture is fully mixed; a nitric acid solution is then added to perform leaching treatment to obtain a leached ore;

[0011] After the leaching process is completed, the leached ore is filtered and washed to obtain phosphate concentrate;

[0012] In the raw ore, the sum of the mass content of iron (Fe%) and the mass content of aluminum (Al%) is: Fe%+Al%>2.5%.

[0013] In one or more technical solutions, the particle size of the raw ore is 2-10 mm.

[0014] In one or more technical solutions, the calcination treatment is calcination at 950-1000° C. for 2-3 hours.

[0015] In one or more technical solutions, the leaching treatment conditions are: temperature 45-50°C, time 3-4h.

[0016] In one or more technical solutions, the mass concentration of nitric acid in the nitric acid solution is 14-25%, and the weight ratio of the nitric acid solution to the calcined ore is 0.5-0.8:1; during dispersion, the mass ratio of the calcined ore to the solvent is 1:1.

[0017] In one or more technical solutions, the calcined ore is dispersed in water, and the mass ratio of the calcined ore to water is 1:1.

[0018] In one or more technical solutions, the phosphorus inhibitor comprises the following raw materials in weight content: 40-45% sodium polyaspartate, 35-40% sodium lignin sulfonate, and 20-25% oxalic acid.

[0019] In one or more technical solutions, the phosphorus inhibitor is added in an amount of 0.1-0.2% of the mass of the calcined ore.

[0020] In one or more technical solutions, the sum of the mass content of iron (Fe%) and the mass content of aluminum (Al%) in the phosphate concentrate is: Fe%+Al%<0.8%.

[0021] In a second aspect, the present application provides a phosphate concentrate, including the phosphate concentrate prepared by the method described in the first aspect.

[0022] The beneficial effects of this application are:

[0023] 1. The method described in the present application can obtain a phosphate concentrate with a total amount of iron and aluminum impurities less than 0.8% by calcining a phosphate ore with a total amount of iron and aluminum impurities greater than 1.5%, and then leaching it once with a nitric acid solution with a mass concentration of 20-25% at 45-50°C and a time of 3-4 hours.

[0024] 2. The method described in this application can effectively reduce the loss of P after adding an acidolysis inhibitor; calculated as P2O5, the P2O5 of the phosphate concentrate can stably reach ≥35%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0026] Figure 1 This is a process flow chart of a method for reducing sesquioxides in phosphate rock using a chemical beneficiation method described in this application. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0028] As used herein, "and / or" includes the term of any and all combinations of one or more associated listed items. The terms used herein are only used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It is further understood that "including", when used in this specification, specifies the stated features, integers, steps, operations, elements and / or compositions, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, compositions and / or combinations thereof.

[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It is further understood that terms, such as defined in commonly used dictionaries, are interpreted in accordance with their meanings in the context of the relevant art and are not in an idealized or overly formal sense unless explicitly so defined herein.

[0030] The exemplary invention described herein may appropriately lack any one or more element limitations that are not specifically disclosed herein. Therefore, the terms "comprise", "include", "contain", etc. should be understood broadly and non-restrictively. In addition, the terminology used herein is used as a description, not a limitation, and it is unintentional to use these terminology expressions that do not include any equivalent characteristics, but only describe some of their characteristics, but various modifications are possible within the scope of the present invention according to the rights. Therefore, although the present invention has been specifically disclosed by preferred embodiments and optional features, the modifications disclosed herein to embody the changes of the present invention may be recorded by those skilled in the art, and such modifications and changes will be considered to be within the scope of the present invention.

[0031] The raw materials or reagents used in the embodiments of the present invention and the comparative examples are all purchased from mainstream manufacturers in the market. The manufacturer or concentration is not specified, and they are all analytically pure raw materials or reagents that can be routinely obtained. As long as the expected effect can be achieved, there is no particular restriction. The instruments and equipment used in the present embodiment are all purchased from major manufacturers in the market. As long as the expected effect can be achieved, there is no particular restriction. If specific techniques or conditions are not specified in the present embodiment, the techniques or conditions described in the literature in this area or according to the product specification are carried out.

[0032] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0033] Obtain raw ore with a particle size of 2-10 mm;

[0034] calcining the raw ore to obtain calcined ore;

[0035] Dispersing the calcined ore in a solvent, adding a nitric acid solution, and performing a leaching treatment to obtain a leached ore;

[0036] After the leaching process is completed, the leached ore is filtered and washed to obtain phosphate concentrate;

[0037] In the raw ore, the sum of the mass content of iron (Fe%) and the mass content of aluminum (Al%) is: Fe%+Al%>2.5%.

[0038] Specifically, the raw ore is phosphate ore; the mass content of iron in the phosphate ore is ≥0.7%, the mass content of aluminum is ≥0.8%, and the sum of the mass content of iron Fe% and the mass content of aluminum Al% is: Fe%+Al%>2.5%, and the mass content of P calculated as P2O5 is ≥26%;

[0039] Specifically, the phosphate ore is calcined at 950-1000°C for 2-3h, and the reactions that occur during calcination are: CaCO3→CaO+CO2; MgCO3→MgO+CO2↑;

[0040] The calcined ore is dispersed in an aqueous solution, wherein the mass ratio of the calcined ore to water is 1:1; the reactions that occur during dispersion are:

[0041] CaO+H2O→Ca(OH)2;

[0042] MgO+H2O→Mg(OH)2;

[0043] After adding nitric acid solution, the dispersed calcined ore undergoes the following reactions during leaching:

[0044] Fe2O3+HNO3→Fe(NO3)3;

[0045] Al2O3+HNO3→Al(NO3)3;

[0046] P2O5+HNO3→H3PO4+H2O;

[0047] Specifically, the inventors found that when nitric acid was used to leach phosphate ore (for example, the iron content of the phosphate ore was 0.74%, the aluminum content was 1.8%, and the P content was 26.28% by mass in terms of P2O5), when the nitric acid concentration reached 35% or more (such as 40%), the weight ratio of the nitric acid solution to the calcined ore was 0.5-0.8:1, and a leaching treatment was performed once at 45-50°C and for 3-4h. The iron and aluminum impurities in the phosphate ore can be partially removed, but at the same time, the P in the phosphate ore is also obviously leached out, resulting in a significant decrease in the P content in the phosphate concentrate and a significant decrease in the grade;

[0048] When nitric acid is used to leaching phosphate ore, it is found that when the concentration of nitric acid is lower than 14% (such as 10%), the weight ratio of nitric acid solution to calcined ore is 0.5-0.8:1, and after leaching at 45-50°C and time 3-4h, the amount of iron and aluminum impurities removed from the phosphate ore is very small, and the total amount of iron and aluminum impurities in the phosphate concentrate remains at a relatively high level, which fails to achieve the effect of reducing the iron and aluminum impurities in the phosphate concentrate.

[0049] Moreover, when the particle size is greater than 10 mm, such as 50 mm, it is found that the total mass content of iron and aluminum in the phosphate concentrate is significantly higher, reaching 1.1%.

[0050] Specifically, the phosphorus inhibitor comprises the following raw materials in weight content: 40-45% sodium polyaspartate, 35-40% sodium lignin sulfonate, and 20-25% oxalic acid.

[0051] When the calcined ore is dispersed in water, by adding an acidolysis inhibitor, it is possible to effectively inhibit P from being leached out by nitric acid solution during leaching, thereby improving the grade of the phosphate concentrate.

[0052] In the present application, the phosphorus inhibitor can form a protective film on the surface of phosphorus oxide of the phosphate mineral, rather than on the surface of iron or aluminum oxide; at the same time, the phosphorus inhibitor can react with calcium ions (Ca 2+ ), preventing further decomposition under acidic conditions, and the oxalic acid in the phosphorus inhibitor can form insoluble oxalate precipitates with phosphorus, further reducing the solubility of phosphorus in nitric acid solution; sodium polyaspartate and sodium lignin sulfonate contain multiple functional groups and can form stable complexes with phosphorus. These complexes are not easily soluble in nitric acid solution, thereby reducing the solubility of phosphorus.

[0053] The following examples and comparative examples further illustrate the method for reducing sesquioxides in phosphate ore by a chemical beneficiation method described in the present application:

[0054] Example 1

[0055] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0056] Weigh 200g of raw ore with a particle size of 10mm into a porcelain dish, place the porcelain dish in an integrated box-type resistance furnace, calcine at 950℃, calcine for 2-3h, and weigh after cooling to room temperature (to obtain calcined ore);

[0057] Weigh 100g of water in a beaker, slowly add 100g of calcined ore under constant stirring to digest and disperse, control the speed at 350r / min, reaction temperature at 45°C, and time for 2h; add 0.1% of the mass of the calcined ore as a phosphorus inhibitor, and continue stirring for 1h;

[0058] After digestion, dilute nitric acid with a mass concentration of 14% was slowly added for leaching. The weight ratio of nitric acid solution to calcined ore was 0.5:1. The leaching temperature was 45°C and the time was 4h.

[0059] After leaching, the filter is filtered; the filter cake is washed with water and then dried to obtain phosphate concentrate.

[0060] Example 2

[0061] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0062] Weigh 200g of the raw ore with a particle size of 6mm into a porcelain dish, place the porcelain dish in an integrated box-type resistance furnace, calcine at 1000℃, calcine for 2h, and weigh after cooling to room temperature (to obtain calcined ore);

[0063] Weigh 100g of water in a beaker, slowly add 100g of calcined ore under constant stirring to digest and disperse, control the speed at 400r / min, the reaction temperature at 50℃, and the time for 2h; add 0.2% of the mass of the calcined ore as a phosphorus inhibitor, and continue stirring for 2h;

[0064] After digestion, dilute nitric acid with a mass concentration of 25% is slowly added for leaching. The weight ratio of nitric acid solution to calcined ore is 0.8:1. The leaching temperature is 50°C and the time is 3h.

[0065] After leaching, the filter is filtered; the filter cake is washed with water and then dried to obtain phosphate concentrate.

[0066] Example 3

[0067] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0068] Weigh 200 g of raw ore with a particle size of 2 mm into a porcelain dish, place the porcelain dish in an integrated box-type resistance furnace, calcine at 980°C for 2.5 h, and weigh after cooling to room temperature (to obtain calcined ore);

[0069] Weigh 100g of water in a beaker, slowly add 100g of calcined ore under constant stirring to digest and disperse, control the speed at 380r / min, reaction temperature at 50°C, and time for 1.5h; add 0.15% of the mass of the calcined ore as a phosphorus inhibitor, and continue stirring for 1-.5h;

[0070] After digestion, dilute nitric acid with a mass concentration of 20% was slowly added for leaching. The weight ratio of nitric acid solution to calcined ore was 0.65:1. The leaching temperature was 48°C and the time was 3.5h.

[0071] After leaching, the filter is filtered; the filter cake is washed with water and then dried to obtain phosphate concentrate.

[0072] Example 4

[0073] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0074] Weigh 200 g of raw ore with a particle size of 2 mm into a porcelain dish, place the porcelain dish in an integrated box-type resistance furnace, calcine at 950°C for 2 h, and weigh after cooling to room temperature (to obtain calcined ore);

[0075] Weigh 100g of water in a beaker, slowly add 100g of calcined ore under constant stirring to digest and disperse, control the speed at 350r / min, reaction temperature at 50°C, and time for 2h; add 0.2% of the mass of the calcined ore as a phosphorus inhibitor, and continue stirring for 2h;

[0076] After digestion, dilute nitric acid with a mass concentration of 25% is slowly added for leaching. The weight ratio of nitric acid solution to calcined ore is 0.5:1. The leaching temperature is 45°C and the time is 3h.

[0077] After leaching, the filter is filtered; the filter cake is washed with water and then dried to obtain phosphate concentrate.

[0078] Example 5

[0079] A method for reducing sesquioxides in phosphate rock by chemical beneficiation comprises the following steps:

[0080] Weigh 200 g of raw ore with a particle size of 8 mm into a porcelain dish, place the porcelain dish in an integrated box-type resistance furnace, calcine at 990°C for 3 hours, and weigh after cooling to room temperature (to obtain calcined ore);

[0081] Weigh 100g of water in a beaker, slowly add 100g of calcined ore under constant stirring to digest and disperse, control the speed at 350r / min, reaction temperature at 45°C, and time for 2h; add 0.1% of the mass of the calcined ore as a phosphorus inhibitor, and continue stirring for 1h;

[0082] After digestion, dilute nitric acid with a mass concentration of 15% is slowly added for leaching. The weight ratio of nitric acid solution to calcined ore is 0.6:1. The leaching temperature is 45°C and the time is 4h.

[0083] After leaching, the filter is filtered; the filter cake is washed with water and then dried to obtain phosphate concentrate.

[0084] Comparative Example 1

[0085] A method for reducing sesquioxides in phosphate rock by chemical beneficiation, without adding an acid decomposition inhibitor, and other conditions are the same as those in Example 1.

[0086] Comparative Example 2

[0087] A method for reducing sesquioxides in phosphate rock by chemical beneficiation, wherein the mass concentration of dilute nitric acid is 40%,

[0088] The remaining conditions are the same as those in Example 1.

[0089] Comparative Example 3

[0090] A method for reducing sesquioxides in phosphate ore by chemical beneficiation, wherein the particle size of the raw ore is 50 mm, and the other conditions are the same as those in Example 1.

[0091] Comparative Example 4

[0092] A method for reducing sesquioxides in phosphate rock by chemical beneficiation, wherein the mass concentration of dilute nitric acid is 10%, and other conditions are consistent with those in Example 1.

[0093] The above-mentioned embodiments and comparative examples use the same raw ore, and the chemical composition is shown in Table 1:

[0094] Table 1

[0095] project N％ <![CDATA[P2O5%]]> CaO% MgO% <![CDATA[Fe2O3%]]> <![CDATA[Al2O3%]]> <![CDATA[SiO2%]]> F％ AI% Ore 0.2 26.28 44.08 5.96 1.24 1.53 4.1 0.4 5.2

[0096] The chemical composition of the phosphate concentrate obtained in Examples 1-5 and Comparative Examples 1-4 is shown in Table 1:

[0097] Table 2

[0098] Group Fe%+Al% <![CDATA[P2O5%]]> CaO% MgO% <![CDATA[Fe2O3%]]> <![CDATA[Al2O3%]]> <![CDATA[SiO2%]]> Example 1 0.71 36.59 49.28 0.37 0.35 0.36 6.8 Example 2 0.55 36.98 50.12 0.24 0.21 0.34 5.92 Example 3 0.67 37.28 49.52 0.51 0.31 0.36 5.54 Example 4 0.72 37.98 49.66 0.36 0.35 0.37 7.33 Example 5 0.56 37.09 50.16 0.3 0.27 0.29 4.14 Comparative Example 1 1.74 30.93 52.64 0.24 0.87 0.87 4.64 Comparative Example 2 0.72 29.06 54.82 0.24 0.33 0.39 4.13 Comparative Example 3 1.45 34.02 51.72 0.26 0.61 0.84 6.02 Comparative Example 4 2.14 28.15 56.39 0.33 0.96 1.18 5.47

[0099] From Table 1 and Table 2, it can be seen that in Examples 1-5, the sum of the mass content of iron Fe% and the mass content of aluminum Al% in the phosphate concentrate is less than 0.8%, while the total amount of iron and aluminum impurities in the raw ore is greater than 2.5%. This shows that through the chemical beneficiation method, especially after leaching with a specific concentration of nitric acid solution (14-25%), iron and aluminum impurities are effectively removed, and the total amount of iron and aluminum impurities is significantly reduced.

[0100] The P2O5 content in the phosphate concentrate prepared in Examples 1-5 stably reaches ≥35%, which is much higher than the P2O5 content in the original ore (26.28%); this is because the addition of phosphorus inhibitors effectively reduces the loss of P during the leaching process, thereby improving the grade of the phosphate concentrate.

[0101] The total Fe%+Al% of the phosphate concentrate of Comparative Example 1 is 1.74%, which is much higher than 0.71% in Example 1. This shows that although there is still a certain decontamination effect without adding an acid hydrolysis inhibitor, the purpose of significantly reducing iron and aluminum impurities cannot be achieved.

[0102] The P2O5 content of Comparative Example 1 is 26.93%, which is lower than 36.59% in Example 1. This indicates that in the absence of a phosphorus inhibitor, more P is dissolved by nitric acid during the leaching process, resulting in a reduction in the P2O5 content in the final phosphate concentrate.

[0103] In the method of Comparative Example 2, although the nitric acid concentration increased, the sum of Fe%+Al% (0.72%) remained at a low level, which indicates that at a higher nitric acid concentration, the total amount of iron and aluminum impurities can be reduced to a lower level.

[0104] However, the P2O5 content of the phosphate concentrate in Comparative Example 2 (29.06%) is much lower than that in Example 1 (36.59%). This is because when the nitric acid concentration reaches 35% or more, the nitric acid not only removes iron and aluminum impurities, but also significantly leaches P in the phosphate ore, causing the P content in the phosphate concentrate to be significantly reduced and the grade to be lowered.

[0105] The performance of the phosphate concentrate of Comparative Example 3 is as follows: the sum of Fe%+Al% is 1.45%, which is higher than 0.71% in Example 1, and the P2O5 content is 34.02%, which is lower than 36.59% in Example 1. It can be seen that Comparative Example 3 uses an ore with a particle size of 50 mm, while Example 1 uses an ore with a particle size of 10 mm. When the particle size is greater than 10 mm (such as 50 mm), the iron and aluminum impurities inside are not easily fully exposed, resulting in the inability to effectively remove these impurities during the chemical beneficiation process. Therefore, the iron and aluminum impurity content in the final phosphate concentrate is still maintained at a relatively high level. In addition, due to the low efficiency of removing iron and aluminum impurities, the grade of P2O5 is indirectly affected.

[0106] The properties of the phosphate concentrate of Comparative Example 4 are as follows: the sum of Fe%+Al% is 2.14%, which is much higher than 0.71% in Example 1; the P2O5 content is 28.15%, which is significantly lower than 36.59% in Example 1.

[0107] Comparative Example 4 uses dilute nitric acid with a mass concentration of 10%, while Example 1 uses dilute nitric acid with a mass concentration of 14%. When the nitric acid concentration is lower than 14%, under the same treatment conditions (such as temperature 45-50°C, time 3-4 hours), the amount of iron and aluminum impurities removed from the phosphate ore is very small, resulting in the total amount of iron and aluminum impurities in the final phosphate concentrate still remaining at a relatively high level, that is, the sum of Fe%+Al% is as high as 2.14%. Since the nitric acid concentration used in Comparative Example 4 is too low, although some iron and aluminum impurities can be removed, it does not have much effect on improving the grade of phosphorus.

[0108] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A method for reducing sesquioxides in phosphate rock by chemical beneficiation, characterized in that: The following steps are involved: Obtaining raw ore; calcining the raw ore to obtain calcined ore; The calcined ore is dispersed in a solvent, a phosphorus inhibitor is added, and the mixture is fully mixed; a nitric acid solution is then added to perform leaching treatment to obtain a leached ore; After the leaching process is completed, the leached ore is filtered and washed to obtain phosphate concentrate; In the raw ore, the sum of the mass content of iron (Fe%) and the mass content of aluminum (Al%) is: Fe%+Al%>2.5%.

2. The method according to claim 1, characterized in that The particle size of the raw ore is 2-10 mm.

3. The method according to claim 1, characterized in that The calcination treatment is calcination at 950-1000° C. for 2-3 hours.

4. The method according to claim 1, characterized in that The conditions of the leaching treatment are: temperature 45-50°C, time 3-4h.

5. The method according to claim 1, characterized in that The mass concentration of nitric acid in the nitric acid solution is 14-25%, and the weight ratio of the nitric acid solution to the calcined ore is 0.5-0.8:1; during dispersion, the mass ratio of the calcined ore to the solvent is 1:

1.

6. The method according to claim 1, characterized in that The calcined ore is dispersed in water, and the mass ratio of the calcined ore to water is 1:

1.

7. The method according to claim 1, characterized in that The phosphorus inhibitor comprises the following raw materials in weight content: 40-45% sodium polyaspartate, 35-40% sodium lignin sulfonate and 20-25% oxalic acid.

8. The method according to claim 1, characterized in that The added amount of the phosphorus inhibitor is 0.1-0.2% of the mass of the calcined ore.

9. The method according to claim 1, characterized in that: The sum of the mass content of iron (Fe%) and the mass content of aluminum (Al%) in the phosphate concentrate is: Fe%+Al%<0.8%.

10. A phosphate concentrate, characterized in that: Including phosphate concentrate prepared by the method according to any one of claims 1-9.

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