Molded silicon-calcium-potassium-magnesium fertilizer, preparation method and application thereof

Abstract

The present invention relates to the field of fertilizers and discloses a shaped silicon-calcium-potassium-magnesium fertilizer and a preparation method and application thereof. The method comprises: (1) uniformly mixing white mud, calcium hydroxide and talcum powder in a granulator, wherein the uniform mixing is performed at a first speed, and a first portion of potassium source solution is added during the uniform mixing process; (2) the mixed material in step (1) is further granulated and shaped in the granulator to obtain a masterbatch, wherein the granulation process is performed at a second speed, and the second portion of potassium source solution is sprayed during the granulation process; (3) the granulation process is then performed at a third speed, and the masterbatch grows; wherein the first speed < the third speed < the second speed. The present invention provides a shaped silicon-calcium-potassium-magnesium fertilizer prepared by the preparation method of the present invention. The raw materials of the method of the present invention are all fine powders, and no ore grinding is required, which saves processes and reduces energy consumption. The mixing, granulation and crushing processes can be performed in one device (high-speed granulator), which can be operated continuously, and the process is simple, efficient and convenient.

Claims

1. A method for preparing a shaped silicon-calcium-potassium-magnesium fertilizer, characterized in that: The method includes: (1) mixing white mud, calcium hydroxide and talc in a granulator, wherein the mixing is performed at a first speed, and adding a first portion of the potassium source solution during the mixing; (2) the mixed material of step (1) is further granulated in a granulator to obtain masterbatch, wherein the granulation process is carried out at a second speed, and the second portion of the potassium source solution is sprayed during the granulation process; (3) The granulation process is then carried out at the third speed, and the masterbatch grows; (4) Sieving the particles obtained in step (3) to obtain particles of the required particle size; (5) aging and curing the particles screened in step (4), then roasting and activating them, and cooling them to obtain granular silicon-calcium-potassium-magnesium fertilizer; in, First speed < third speed < second speed; The speed difference between the first speed and the third speed is 800-1800 rpm; The speed difference between the third speed and the second speed is 1200-2800 rpm.

2. The preparation method according to claim 1, wherein The speed difference between the first speed and the third speed is 1000-1500 rpm; and / or The speed difference between the third speed and the second speed is 1500-2500 rpm; and / or The time for step (1) is 5-40 minutes, the time for step (2) is 2-30 minutes, and the time for step (3) is 5-60 minutes.

3. The preparation method according to claim 2, wherein The time for step (1) is 10-20 minutes, the time for step (2) is 2-10 minutes, and the time for step (3) is 8-20 minutes.

4. The preparation method according to claim 3, wherein The operating conditions of step (1) include: rotor speed 500-1500 rpm, time 10-20 min; and / or The operating conditions of step (2) include: rotor speed 3000-5000 rpm, time 2-10 min; and / or The operating conditions of step (3) include: rotor speed of 1500-2800 rpm, time of 8-20 min.

5. The preparation method according to claim 1, wherein The first part of the potassium source solution accounts for 30-50% by weight of the total potassium source solution, and the second part of the potassium source solution accounts for 50-70% by weight of the total potassium source solution; and / or The weight of the potassium source in the total potassium source solution is 5%-30% of the weight of the total materials in step (1), and the weight of water in the total potassium source solution is 20%-50% of the weight of the total materials in step (1).

6. The preparation method according to claim 5, wherein The potassium source is potassium salt.

7. The preparation method according to claim 6, wherein The potassium source is K2CO3.

8. The method for preparing a shaped silicon-calcium-potassium-magnesium fertilizer according to claim 1, wherein: The weight ratio of the white mud, calcium hydroxide and talc is 1: (0.4-0.9): (0.1-0.5).

9. The method for preparing the shaped silicon-calcium-potassium-magnesium fertilizer according to claim 8, wherein: The weight ratio of the white mud, calcium hydroxide and talc is 1: (0.6-0.8): (0.15-0.3).

10. The method for preparing the shaped silicon-calcium-potassium-magnesium fertilizer according to claim 1, wherein: The white mud is fly ash aluminum extraction residue, wherein the SiO2 content is 50-80%; and / or The talc powder contains 40-80 wt % SiO 2 and 20-60 wt % MgO.

11. The method for preparing a shaped silicon-calcium-potassium-magnesium fertilizer according to claim 1, wherein: The method further comprises: screening the particles obtained in step (3) to obtain particles with a particle size of 1-5 mm, particles with a size of less than 1 mm, and particles with a size of more than 5 mm; Particles with a diameter less than 1 mm are used as the raw material for step (3), and particles with a diameter greater than 5 mm are used as the raw material for step (2).

12. The method for preparing a shaped silicon-calcium-potassium-magnesium fertilizer according to claim 1, wherein: The aging temperature is 30-100° C., and the aging time is 0.5-12 h.

13. The method for preparing the shaped silicon-calcium-potassium-magnesium fertilizer according to claim 1, wherein: The calcination activation temperature is 700-1000° C. and the time is 0.5-3 hours.

14. The method for preparing a shaped silicon-calcium-potassium-magnesium fertilizer according to claim 13, wherein: The calcination activation temperature is 850-1000° C. and the time is 1-2.5 hours.

15. The shaped silicon-calcium-potassium-magnesium fertilizer prepared by the preparation method according to any one of claims 1 to 14.

16. Application of the preparation method of the shaped silicon-calcium-potassium-magnesium fertilizer according to any one of claims 1 to 14 in the field of fertilizer preparation technology.

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