CN111018571A - Method for activating and utilizing low-grade phosphate ore - Google Patents
Method for activating and utilizing low-grade phosphate ore Download PDFInfo
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- CN111018571A CN111018571A CN201911157121.6A CN201911157121A CN111018571A CN 111018571 A CN111018571 A CN 111018571A CN 201911157121 A CN201911157121 A CN 201911157121A CN 111018571 A CN111018571 A CN 111018571A
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- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B17/00—Other phosphatic fertilisers, e.g. soft rock phosphates, bone meal
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Abstract
The invention discloses a method for activating and utilizing low-grade phosphorite, which comprises the steps of crushing the low-grade phosphorite, uniformly mixing the crushed low-grade phosphorite with slag acid in proportion, completely reacting at normal temperature, and drying to obtain a slow-release synergistic phosphate fertilizer; wherein P of the low-grade phosphate ore2O5The content is 15-20 wt%, the slag acid is a slurry-like byproduct of phosphoric acid produced by a wet method, and the pH value of the slag acid is 1.5-3.0. The method can recycle the slag acid which is a byproduct in the wet-process phosphoric acid production and utilize the wet-process phosphoric acid as resources, simultaneously reasonably utilizes the low-grade phosphate rock powder, the pH value of the prepared sustained-release synergistic phosphate fertilizer is 3.29, the sustained-release synergistic phosphate fertilizer is applied to soil and is beneficial to improving the effectiveness of nutrients in the soil, the quick-acting phosphorus in the mixture is preferentially utilized in the early growth and development stage of plants, and the indissolvable phosphorus in the phosphate rock powder can be further absorbed and utilized after the root systems grow to be strong, so that the method has.
Description
Technical Field
The invention belongs to the technical field of novel agricultural fertilizers, and relates to a method for activating and utilizing low-grade phosphate ores.
Background
Phosphate rock is a main raw material for producing phosphate fertilizer and is one of important non-metal minerals. The reserve of phosphorite in China is about 33 hundred million tons (USGS, 2018), and is located in the second place of the world and mainly distributed in Hubei province, Yunnan province, Sichuan province and Guizhou province. Although the phosphorite resources in China are rich, the phosphorite grade is low, and the rich ore resources with the grade higher than 30% are relatively few and only account for about 10% of all the phosphorite resources.
China mainly uses middle-low grade phosphorite, and the average grade is only about 18 percent and is far lower than the average level in the world. The medium and low grade phosphorite can meet the requirement of producing high concentration phosphorus compound fertilizer only through the mineral dressing and enrichment process, which not only needs great economic investment, but also can cause potential threat to the surrounding environment. Therefore, the efficient utilization of the medium and low grade phosphorite is enhanced, the butt joint of the phosphorite exploitation engineering technology and the agricultural efficient utilization is realized, and the method has important significance for improving the utilization efficiency of the phosphorite and realizing the sustainable development of national agriculture.
The slag acid is impurity generated in the wet-process phosphoric acid industrial production, contains anions and cations such as Fe, Mg, P and the like, has extremely low pH value which is about 1.5-3.0 according to the test. The direct discharge of the slag acid can seriously affect the surrounding environment and cause resource waste, and the effective utilization of the slag acid is greatly limited because the slag acid has strong acidity and is inconvenient to transport. Research shows that ammonium bicarbonate can be neutralized with slag acid, and the ammonium bicarbonate and the slag acid are dried and crushed to prepare powder for direct sale. In addition, the slag acid can be used for directly producing agricultural grade monoammonium phosphate without centrifugal separation, or the slag acid is used for supplementing phosphorus in the production process of the ordinary superphosphate and the heavy calcium after the centrifugal separation, but the production of the ordinary superphosphate and the heavy calcium has high requirements on the content of water-soluble phosphorus, and the slag acid has low content of water-soluble phosphorus, so that the utilization efficiency is extremely low.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for preparing a sustained-release synergistic phosphate fertilizer by using low-grade phosphate ore and slag acid to react and activate the low-grade phosphate ore and utilize the low-grade phosphate ore.
The invention adopts the following technical scheme:
a method for activating and utilizing low-grade phosphorite comprises the steps of crushing the low-grade phosphorite, uniformly mixing the crushed low-grade phosphorite and slag acid in proportion, completely reacting at normal temperature, and drying to obtain a slow-release synergistic phosphate fertilizer;
wherein P of the low-grade phosphate ore2O5The content is 15-20 wt%, the slag acid is a slurry-like byproduct of phosphoric acid produced by a wet method, and the pH value of the slag acid is 1.5-3.0.
In the technical scheme, the mass ratio of the crushed low-grade phosphate ore to the added slag acid is (6.5-7.5): 3.0.
further, in the technical scheme, the reaction time is 48-60 h.
Still further, in the method for preparing the slow-release controlled-release synergistic phosphate fertilizer by using the low-grade phosphate ore and the slag acid, the low-grade phosphate ore comprises the following components in parts by weight:
17.5-18.6% of phosphorus pentoxide, 0.045-0.053% of water-soluble phosphorus, 3.95-4.64% of citrate-soluble phosphorus, 26.8-29.5% of CaO26, 4.58-4.86% of MgO and Fe2O31.52-1.72％。
In a preferred embodiment, in the above method for preparing a slow-release controlled-release synergistic phosphate fertilizer by using low-grade phosphate ore and slag acid, the low-grade phosphate ore comprises the following components in parts by weight:
18.15 percent of phosphorus pentoxide, 0.05 percent of water-soluble phosphorus, 4.4 percent of citrate-soluble phosphorus, 27.9 percent of CaO, 4.7 percent of MgO and Fe2O31.6％。
Still further, in the method for preparing the slow-release controlled-release synergistic phosphate fertilizer by using the low-grade phosphate ore and the slag acid, the slag acid comprises the following components in parts by weight:
P2O533.8-36.2％，CaO 5.05-5.28％，MgO 1.95-2.28％，Fe2O39.48-9.64％。
in a preferred embodiment, in the above method for preparing a slow-release controlled-release synergistic phosphate fertilizer by using low-grade phosphate ore and slag acid, the slag acid comprises the following components in parts by weight:
P2O535％，CaO 5.2％，MgO 2.1％，Fe2O39.7％。
preferably, in the above technical scheme, the particle size of the crushed low-grade phosphate ore is 90% passing through a 100-mesh sieve.
Preferably, in the above technical solution, the slag acid is slurry slag acid which has not been subjected to solid-liquid separation.
Specifically, in a specific embodiment, the pH value of the slow-release and controlled-release synergistic phosphate fertilizer prepared by the method provided by the invention is 3.29, the content of water-soluble phosphorus is 11%, and the content of citrate-soluble phosphorus is 14%.
In the practical application process of the sustained-release synergistic phosphate fertilizer prepared by the invention, partial nitrogen fertilizer, sulfur fertilizer, zinc fertilizer and the like can be applied in a matched manner according to the physical and chemical properties of soil.
Compared with the prior art, the invention has the following advantages:
(1) one of the raw materials is the byproduct slag acid in the wet-process phosphoric acid production, so that the problem of comprehensive utilization of industrial wastes is solved to a certain extent, and the resource utilization rate is improved;
(2) one of the raw materials is certain low-grade powdered rock phosphate, a novel technical approach is found for the comprehensive utilization of the powdered rock phosphate, the utilization cost is reduced, and the utilization efficiency of the powdered rock phosphate is improved to a certain extent;
(3) the pH value of the mixture of the phosphate rock powder and the slag acid is 3.29, the mixture is applied to soil to be beneficial to improving the effectiveness of nutrients in the soil, the raw material slag acid contains part of phosphoric acid, and most of low-grade phosphate rock powder is insoluble phosphorus, so that the actual effect is similar to that of a slow-control fertilizer when the raw material slag acid and the low-grade phosphate rock powder are mixed and applied, the early growth and development of plants depend on the quick-acting phosphorus applied to the mixture in the soil, and after the quick-acting phosphorus is absorbed and utilized, the plants grow for a period of time to form a stronger root system, so that the insoluble phosphorus in the phosphate rock powder can be further absorbed and utilized. In the period, as the slag acid has certain acidity, the indissolvable phosphorus in the ground phosphate rock can be gradually dissolved and released;
(4) the invention provides a new utilization idea for the current situation of utilizing low-grade phosphorite at high cost, and utilizes byproducts of industrial production to a certain extent, thereby realizing comprehensive utilization of resources and reducing resource waste.
Drawings
FIG. 1 is a plot showing the growth of maize plants corresponding to each of the different treatment groups in an embodiment of the present invention.
Detailed Description
The following detailed description of embodiments of the invention is provided in connection with the accompanying drawings and the examples.
The following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.
The experimental procedures used in the following examples are conventional unless otherwise specified.
The raw materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
The low-grade phosphorite used in the embodiment of the invention is produced from a phosphorite in Yunnan province, and the composition of the low-grade phosphorite is approximately as follows:
18.15 percent of phosphorus pentoxide, 0.05 percent of water-soluble phosphorus, 4.4 percent of citrate-soluble phosphorus, 27.9 percent of CaO, 4.7 percent of MgO and Fe2O31.6％。
Examples
Grinding low-grade phosphate ore to 90% according to requirements, and sieving the ground low-grade phosphate ore with a 100-mesh sieve, wherein the ground low-grade phosphate ore and slurry slag acid are 70% in mass ratio: stirring and mixing 30% of the mixture fully, and then placing the mixture in a thermostat with the temperature of 25-30 ℃ for fully reacting for 48 hours; then taking out, fully drying at 105 ℃, fully grinding the obtained product, and sieving by a 100-mesh sieve.
The basic nutrient content of the used slag acid is as follows: p2O5The total content of the components is 35.36 percent, CaO is 5.18 percent, and K2O2.18％，MgO 2.11％，Fe2O39.71％，SO4 2-9.52％。
The basic nutrient content of the prepared slow-release and controlled-release synergistic phosphate fertilizer mixture is as follows: p2O5The total content is 26.67 percent (wherein, the water-soluble phosphorus content is 11 percent, the citric soluble phosphorus content is 14 percent), CaO 29 percent and K2O 0.95％，MgO 4％，Fe2O32.8％，SiO224％。
Example of the implementation
Potting experiments were carried out in the solar glass greenhouse of the university of agriculture, china, 2016, 9, 24.
1 materials and methods
Test materials: corn (corn)
And (3) test treatment:
treatment 1: control without phosphorus application;
and (3) treatment 2: applying calcium superphosphate treatment;
and (3) treatment: applying industrial common low-grade phosphate rock powder with the grain size of 100 meshes;
and (4) treatment: the slow-release and controlled-release synergistic phosphate fertilizer mixture prepared according to the embodiment 1 of the invention is applied, namely the low-grade phosphate rock powder and the slag acid are mixed according to the mass ratio of 70%: treatment of 30% of the mixture.
Test soil: the soil to be tested was taken from acidic red soil in the Brookfield of the university of agriculture, south China, Huizhou, Guangdong. Physical and chemical properties of soil foundation: pH of 3.9 (soil-water ratio of 1: 5), quick-acting phosphorus 2.07mg kg-1Organic matter 3.24g kg-1Quick-acting potassium of 14mgkg-1Inorganic nitrogen 25.25mg kg-10.28g kg of total nitrogen-1。
Each treatment was conducted with the same total phosphorus amount added, except that the type of phosphorus applied was different; and the addition amounts of other nutrients are completely the same and can meet the growth requirements of plants.
2 results and analysis
2.1 Effect of different treatments on corn seedling growth
As shown in FIG. 1, after the difference in the aerial parts of the plants is significant, the plants are harvested, and before harvesting, the plant height, SPAD value and other indexes of the plants treated differently are measured. Deactivating enzyme at 105 deg.c for 30min, stoving at 70 deg.c for 48 hr, and measuring the dry weight of the overground part and the dry weight of the root. After the dry weight measurement, the overground part samples were digested with sulfuric acid and hydrogen peroxide, and the plant phosphorus was measured by vanadium molybdenum yellow colorimetry (Johnson and Ulrich, 1959).
The data was analyzed for variance using SAS software.
TABLE 1 Effect of different treatments on corn seedling growth
As can be seen from the results in table 1, the plant height, SPAD value, dry weight of the above-ground part, and weight average of the root of the slow-release and controlled-release synergistic phosphate fertilizer mixture prepared in example 1 of the present invention were the highest values among all treatments, and were significantly different from the control and from each of the other treatments. The dry weight of the overground part of the slow-release and controlled-release synergistic phosphate fertilizer mixture prepared in the embodiment 1 of the invention is 2.21 times of that of the contrast treatment, and is increased by 75 percent compared with the treatment of applying ordinary calcium superphosphate; the dry weight of the root system increased by about 42% compared to the other treatments.
2.2 Effect of different treatments on the phosphorus concentration and phosphorus uptake of the overground part of the corn seedling stage
TABLE 2 influence of different treatments on the phosphorus concentration and phosphorus uptake of the overground part of the corn seedling stage
Analysis of the results in table 2 shows that the slow-release and controlled-release synergistic phosphate fertilizer mixture prepared in example 1 of the present invention significantly improves phosphorus absorption of the maize plants at the seedling stage compared to other treatments, and increases the phosphorus absorption of the maize plants by 124% compared to the superphosphate treatment. By comparing the content of available phosphorus in soil after the four treated plants are harvested, the content of available phosphorus in soil is the highest when the sustained-release synergistic phosphate fertilizer mixture prepared in the embodiment 1 of the invention is applied, which indicates that the treatment of the invention provides the most available phosphorus for the corn to grow under the same conditions, and the treatment is most beneficial to the growth of the corn.
3 conclusion
The results of the tests show that the corn plants with the sustained/controlled release synergistic phosphate fertilizer mixture of the invention obtained in example 1 grew best and better than the conventional calcium superphosphate and powdered rock phosphate alone. The dry weight of the aerial parts of the corns on which the slow-release and controlled-release synergistic phosphate fertilizer mixture prepared in the embodiment 1 of the invention is applied is 2.21 times of that of the corns without the phosphate control, which is increased by 75 percent compared with the treatment of applying common calcium superphosphate, and the dry weight of the root system is increased by about 42 percent compared with other three treatments. After the plants are harvested, the content of the available phosphorus in the soil is far higher than that of the available phosphorus in other treatments, so that the available phosphorus absorbed and utilized by the corn is the highest, and the phosphorus concentration and phosphorus absorption on the overground part of the corn are obviously increased. The comprehensive utilization technology of the low-grade ground phosphate rock added industrial byproduct slag acid can effectively promote the growth of the corn and increase the nutrient absorption and accumulation.
Finally, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. A method for activating and utilizing low-grade phosphorite is characterized by comprising the steps of crushing the low-grade phosphorite, uniformly mixing the crushed low-grade phosphorite with slag acid in proportion, completely reacting at normal temperature, and drying to obtain a slow-release and controlled-release synergistic phosphate fertilizer;
wherein P of the low-grade phosphate ore2O5The content is 15-20 wt%, the slag acid is a slurry-like byproduct of phosphoric acid produced by a wet method, and the pH value of the slag acid is 1.5-3.0.
2. The method according to claim 1, characterized in that the ratio of the low-grade phosphate ore crushing to the addition of the slag acid by mass is (6.5-7.5): 3.0.
3. the process according to claim 1 or 2, wherein the reaction time is 48-60 h.
4. The method according to any one of claims 1-3, characterized in that the low-grade phosphate ore comprises the following components in parts by weight:
17.5-18.6 percent of phosphorus pentoxide, 0.045-0.053 percent of water-soluble phosphorus, 3.95-4.64 percent of citrate-soluble phosphorus, 26.8-29.5 percent of CaO, 4.58-4.86 percent of MgO and Fe2O31.52-1.72％。
5. The method according to claim 4, characterized in that the low-grade phosphate ore comprises the following components in parts by weight:
18.15 percent of phosphorus pentoxide, 0.05 percent of water-soluble phosphorus, 4.4 percent of citrate-soluble phosphorus, 27.9 percent of CaO, 4.7 percent of MgO and Fe2O31.6％。
6. The method according to any one of claims 1 to 3, wherein the slag acid comprises the following components in parts by weight:
P2O533.8-36.2％，CaO 5.05-5.28％，MgO 1.95-2.28％，Fe2O39.48-9.64％。
7. the method of claim 6, wherein the slag acid comprises the following components in parts by weight:
P2O535％，CaO 5.2％，MgO 2.1％，Fe2O39.7％。
8. the method of any one of claims 1 to 7, wherein the particle size of the crushed low-grade phosphate ore is 90% passing through a 100-mesh sieve.
9. The method according to any one of claims 1 to 7, wherein the slag acid is slurry slag acid which has not been subjected to solid-liquid separation.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113277885A (en) * | 2021-06-09 | 2021-08-20 | 四川大学 | Resource utilization method of phosphoric acid residues |
| CN115626841A (en) * | 2022-11-07 | 2023-01-20 | 云南云天化股份有限公司 | Preparation method of calcium-magnesium-rich citrate soluble phosphate fertilizer special for macadamia nuts |
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| CN102976858A (en) * | 2012-12-05 | 2013-03-20 | 何明生 | Slow-release phosphate fertilizer regenerated from phosphorus-containing waste residue |
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| CN106365747A (en) * | 2016-09-08 | 2017-02-01 | 郑州大学 | Method for directly producing compound fertilizer by using phosphate tailings |
| WO2019118754A1 (en) * | 2017-12-13 | 2019-06-20 | University Of Florida Research Foundation | Methods and compositions for slow release phosphorus fertilizers |
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2019
- 2019-11-22 CN CN201911157121.6A patent/CN111018571A/en active Pending
Patent Citations (7)
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113277885A (en) * | 2021-06-09 | 2021-08-20 | 四川大学 | Resource utilization method of phosphoric acid residues |
| CN115626841A (en) * | 2022-11-07 | 2023-01-20 | 云南云天化股份有限公司 | Preparation method of calcium-magnesium-rich citrate soluble phosphate fertilizer special for macadamia nuts |
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Application publication date: 20200417 |