Preparation method of mineral conditioner based on phosphorus and potassium synergistic activation of low-grade potassium phosphate ore
By employing a three-stage synergistic activation system of mechanical ball milling, thermal activation, and hydrothermal activation, the mineral crystal structure is disrupted, achieving synergistic activation of phosphorus, potassium, and trace elements. This process produces a multifunctional mineral conditioner, solving the problem of efficient utilization of low-grade potassium phosphate resources, reducing energy consumption, and simplifying the process flow.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHENGDU UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2026-01-20
- Publication Date
- 2026-05-01
AI Technical Summary
In the current technology, low-grade potassium phosphate resources have not been effectively utilized. The activation process of phosphorus and potassium is complex, energy-intensive, and the products have limited functions, making it difficult to achieve synergistic activation of phosphorus and potassium and efficient utilization of resources.
A three-stage synergistic activation system consisting of mechanical ball milling, thermal activation, and hydrothermal activation was adopted. Mechanical ball milling pretreatment was used to destroy the mineral crystal structure, medium- and low-temperature thermal activation was used to promote crystal reconstruction, and hydrothermal activation was used to complete nutrient conversion, thus preparing a mineral conditioner containing phosphorus, potassium, and trace elements.
This method achieves synergistic activation of phosphorus, potassium, and trace elements in low-grade potassium phosphate rock, producing a multifunctional mineral conditioner that reduces energy consumption, simplifies the process, is environmentally friendly, and conforms to the principles of green chemistry.
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Figure CN121949014A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemical production technology and relates to a method for preparing a mineral conditioner, specifically a method for preparing a mineral conditioner based on the synergistic activation of phosphorus and potassium in low-grade potassium phosphate rock. Background Technology
[0002] Phosphorus and potassium are essential macronutrients for crop growth and development, playing a decisive role in improving crop yield and quality. Currently, agricultural phosphate and potash fertilizers mainly rely on the chemical processing of high-grade phosphate rock and soluble potassium salt resources. It is noteworthy that my country possesses abundant low-grade potassium-phosphate resources, such as the deposits concentrated in the Hanyuan area of Sichuan Province, with reserves estimated at approximately 2 billion tons. These ores are primarily composed of potassium feldspar and apatite, with a dense structure. Although they contain phosphorus, potassium, and various trace elements, the nutrients are mostly present in stable silicate and phosphate forms, making them difficult for crops to directly absorb, thus hindering their effective industrial utilization.
[0003] Current technologies for activating and utilizing phosphorus and potassium typically target high-grade ores and follow a single-element activation approach. For phosphorus activation, while the mainstream wet phosphoric acid process can efficiently extract phosphorus, it generates a large amount of phosphogypsum solid waste and is largely ineffective against associated potassium feldspar. High-temperature roasting can convert phosphorus into structure-soluble phosphorus, but often fails to release potassium simultaneously. For potassium activation, while high-temperature decomposition or hydrothermal methods of potassium feldspar can extract potassium, the chemical environment during the process easily fixes phosphorus in apatite into an ineffective form, resulting in phosphorus loss. Therefore, existing processes are essentially sequential processing modes of "phosphorus first, then potassium" or "potassium first, then phosphorus," failing to achieve synergistic activation of phosphorus and potassium. This separation-activation approach not only leads to complex processes and high energy and material consumption but also faces challenges such as difficulty in separating phosphorus and potassium, and the generation of harmful impurities such as fluorides and solid waste. The final products are mostly chemical fertilizers with single nutrients, which cannot directly convert low-grade potassium phosphate rock into soil conditioners that supply phosphorus, potassium and various beneficial trace elements. The added value of the products is low and it is difficult to meet the needs of modern agriculture for comprehensive soil improvement.
[0004] Therefore, there is an urgent need in this field to develop a method for the synergistic activation of potassium and phosphorus in low-grade potassium phosphate rock. This method can simultaneously disrupt the stable crystal structure of potassium feldspar and apatite, avoid mutual inhibition of nutrient elements during the activation process, and directly transform the raw ore into a multi-element mineral conditioner with soil-improving functions, thereby achieving the clean, efficient, and high-value utilization of low-grade potassium phosphate resources. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing a mineral conditioner based on the synergistic activation of potassium and phosphorus in low-grade potassium phosphate rock. By using potassium-phosphorus synergistic activation and mechanical ball milling pretreatment, this method solves the problems of difficulty in synergistic activation of potassium and phosphorus, complex process flow, high energy consumption, and single product function in the prior art.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a mineral conditioner based on the synergistic activation of phosphorus and potassium in low-grade potassium phosphate rock, wherein the mineral conditioner contains phosphorus, potassium and trace elements, wherein the trace elements include at least one of iron, magnesium, calcium, manganese, titanium, sodium and aluminum, wherein the effective phosphorus content is 10-12% and the effective potassium content is 3-4%.
[0007] The present invention further provides a method for preparing the above-mentioned mineral conditioning agent.
[0008] Preferably, the mineral conditioning agent is obtained by mixing low-grade potassium phosphate rock with ammonium sulfate and then subjecting it to mechanical ball milling, thermal activation experiments, and hydrothermal experiments.
[0009] Preferably, the steps include:
[0010] S1. Mechanical ball milling: Potassium phosphate ore is ground into powder, mixed with ammonium sulfate, and then ground in a ball mill jar to obtain a mechanically activated product;
[0011] S2. Thermal activation experiment: The mechanically activated product obtained in step S1 is placed in a crucible, sealed, and heated in a muffle furnace to obtain a thermally activated product;
[0012] S3. Hydrothermal Experiment: The thermally activated product obtained in step S2 is mixed with quicklime and ground in a ball mill to obtain a composite material. The obtained composite material is placed in a reaction vessel with water added, and the reaction vessel is placed in an electric heating drying oven to react and obtain a mineral conditioning agent.
[0013] Preferably, the grinding time in the ball mill jar in step S1 is 1 hour, so the mass ratio of potassium phosphate powder to ammonium sulfate is 20:1.
[0014] Preferably, the reaction temperature in the muffle furnace in step S2 is 400°C and the reaction time is 6 hours.
[0015] Preferably, in step S3, the mass ratio of the thermally activated product to quicklime is 7:2, the grinding time in the ball mill is 1 hour, the reaction time in the reactor in the electric heating drying oven is 16 hours, and the temperature of the electric heating drying oven is 180°C.
[0016] The present invention further provides the application of the above-mentioned mineral conditioner in the preparation of multi-element compound fertilizer.
[0017] The beneficial effects of this invention are:
[0018] 1. Utilization of all elements
[0019] This invention uses low-grade potassium phosphate ore as raw material, overcoming the limitations of traditional processes that only extract single elements. Through specific activation technology, it achieves the synergistic activation and utilization of multiple elements such as phosphorus and potassium in the ore without the addition of additional nutrients. This invention prepares a novel multifunctional mineral conditioner that can simultaneously provide crops with major nutrients such as phosphorus and potassium, as well as multiple trace elements, significantly different from traditional single-element potassium fertilizers, phosphate fertilizers, or potassium-silicon fertilizers.
[0020] 2. Technological Innovation and Green Production
[0021] This invention employs a three-stage synergistic activation system of "mechanical ball milling - thermal activation - hydrothermal activation". Mechanical ball milling pretreatment (room temperature) disrupts the mineral crystal structure, medium-low temperature thermal activation (400℃) promotes crystal reconstruction, and hydrothermal activation (180℃) completes nutrient conversion. This process is significantly lower than traditional high-temperature processes, effectively reducing energy consumption and simplifying the operation process.
[0022] 3. Environmentally friendly characteristics
[0023] The entire production process has significant environmental advantages: no strong acids or alkalis are used, no solid waste such as phosphogypsum is generated, and no harmful gases such as fluorine are emitted, which conforms to the principles of green chemistry and has good environmental compatibility. Attached Figure Description
[0024] Figure 1 This is a flowchart of the preparation method of the phosphorus and potassium mineral conditioner in this invention. Detailed Implementation
[0025] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0026] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.
[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0028] It should be noted that the potassium phosphate ore used in this invention was mined from the Dahongshan potassium phosphate mine in Hanyuan County, Sichuan Province.
[0029] Example 1: Preparation of potassium-phosphorus mineral conditioner
[0030] 1. Method
[0031] Using potash phosphate ore as raw material, the potash phosphate ore is first mechanically ball-milled with ammonium sulfate, and the milled product undergoes a thermal activation reaction. The product is then mixed with quicklime and subjected to a combination of mechanical ball milling and hydrothermal reaction, thereby achieving the utilization and conversion of low-grade potash phosphate ore. This synergistic activation method of phosphorus and potassium includes mechanical ball milling experiments, thermal activation experiments, and hydrothermal experiments. Figure 1 The specific steps are as follows:
[0032] (1) Phosphorus and potassium synergistic activation mechanical ball milling experiment
[0033] The mechanical ball milling experiment used a German planetary ball mill. Potassium phosphate ore and grinding balls were placed in a ball mill jar at a ball-to-material ratio of 18:1 and ground for 1 hour to obtain potassium phosphate ore powder. Then, the ground potassium phosphate ore powder and ammonium sulfate were placed in a ball mill jar at a mass ratio of 20:1 and a ball-to-material ratio of 18:1 and ground for 1 hour to obtain a mechanically activated composite material.
[0034] (2) Phosphorus and potassium synergistic activation thermal activation experiment
[0035] The product obtained from the aforementioned steps was subjected to a thermal activation experiment. A certain amount of mechanically activated composite material was weighed, placed in a crucible, sealed with high-temperature adhesive, and placed in a muffle furnace. The crucible was kept at 400°C for 6 hours to obtain the product after mechanical and thermal activation.
[0036] (3) Phosphorus and potassium synergistic activation hydrothermal experiment
[0037] To ensure uniform mixing of the materials and activator and to achieve optimal activation rates for phosphorus and potassium, mechanical ball milling and hydrothermal experiments were conducted sequentially. First, the product obtained in the previous steps was ground with quicklime at a mass ratio of 7:2 and a ball-to-material ratio of 18:1 in a ball mill jar for 1 hour to obtain a composite material. A certain amount of the composite material was weighed and placed in a reaction vessel, along with a certain amount of distilled water. The reaction vessel liner was then placed inside a steel outer shell, the lid was closed, and the screws were tightened. The vessel was then placed in an electrically heated drying oven and kept at a constant temperature of 180℃ for 16 hours, ultimately yielding a novel phosphorus and potassium mineral conditioner containing phosphorus, potassium, and various trace elements for complete elemental supplementation.
[0038] 2. Results Analysis
[0039] Three parallel samples were designed for each phosphorus-potassium synergistic activation experiment. The experimental data of the original sample and each product are shown in Tables 1 and 2, respectively. The results showed that the original sample contained 16.02% P2O5 and 6.56% K2O, indicating it was a low-grade potash phosphate rock with the lowest available phosphorus and available potassium contents, ranging from 8.32% to 11.13% and 0.072% to 0.075%, respectively. In the mechanical activation experiment, the contents of available phosphorus and available potassium were significantly increased, with the available phosphorus and available potassium contents increasing by [missing information]. The effective phosphorus and potassium contents reached 14.63-15.56% and 3.75-3.85% respectively in the thermal activation experiment and 13.73-14.38% and 3.54-3.64% respectively in the mechanical activation experiment. In the hydrothermal experiment, the effective phosphorus content decreased slightly (10.49-10.82%), but the effective potassium content was further increased compared to the thermal activation experiment (3.53-3.86%), and the activation rate reached the maximum value (73-79%). It should be noted that although the effective phosphorus and effective potassium contents decreased slightly in the final experimental group, the potassium activation rate reached more than 60%, while ensuring that the phosphorus activation rate remained above 90% in the entire experimental group. The phosphorus and potassium contents have met the technical indicators of GB / T 20412-2021 "Granular Calcium Magnesium Phosphate Fertilizer" and GB / T 36207-2018 "Silicon Calcium Potassium Magnesium Fertilizer" issued by the National Standardization Management Committee.
[0040] Table 1 Chemical composition data of original samples in the experiment of potassium phosphate rock synergistic activation with phosphorus and potassium
[0041]
[0042] Table 2. Data on the effective phosphorus and potassium content and activation rate of the experimental products from the synergistic activation of potassium phosphate rock.
[0043]
[0044] The above-described embodiments are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.
Claims
1. A mineral conditioner based on the synergistic activation of phosphorus and potassium in low-grade potassium phosphate rock, characterized in that: The mineral conditioner contains phosphorus, potassium, and trace elements, including at least one of iron, magnesium, calcium, manganese, titanium, sodium, and aluminum. The effective phosphorus content is 10-12%, and the effective potassium content is 3-4%.
2. The method for preparing the mineral conditioner according to claim 1, characterized in that: The mineral conditioner is made from low-grade potassium phosphate rock as raw material. It is mixed with ammonium sulfate and subjected to mechanical ball milling and thermal activation experiments to obtain an intermediate product. Then, it is mixed with quicklime and subjected to mechanical ball milling and hydrothermal experiments to obtain the mineral conditioner.
3. The preparation method according to claim 2, characterized in that: Includes the following steps: S1. Mechanical ball milling: Potassium phosphate ore is ground into powder, mixed with ammonium sulfate, and then ground in a ball mill jar to obtain a mechanically activated product; S2. Thermal activation experiment: The mechanically activated product obtained in step S1 is placed in a crucible, sealed, and heated in a muffle furnace to obtain a thermally activated product; S3. Hydrothermal Experiment: The thermally activated product obtained in step S2 is mixed with quicklime and ground in a ball mill to obtain a composite material. The obtained composite material is placed in a reaction vessel with water added, and the reaction vessel is placed in an electric heating drying oven to react and obtain a mineral conditioning agent.
4. The preparation method according to claim 3, characterized in that: The grinding time in the ball mill jar in step S1 is 1 hour, so the mass ratio of potassium phosphate powder to ammonium sulfate is 20:
1.
5. The preparation method according to claim 3, characterized in that: The reaction temperature in the muffle furnace in step S2 is 400°C, and the reaction time is 6 hours.
6. The preparation method according to claim 3, characterized in that: In step S3, the mass ratio of the thermally activated product to quicklime is 7:2, the grinding time in the ball mill is 1 hour, the reaction time in the reactor in the electric heating drying oven is 16 hours, and the temperature of the electric heating drying oven is 180°C.
7. The application of the mineral conditioner according to claim 1 in the preparation of multi-element compound fertilizer.