Method for preparing silicon fertilizer from iron tailings

Abstract

The invention aims to provide a method for preparing a silicon fertilizer by using iron tailings to solve the problems existing in the prior art for preparing a solid silicon fertilizer by using iron tailings. The method comprises the following steps: 1) mixing and stirring a compound activator, water and iron tailings, performing ultrasonic treatment to obtain a mixture, and performing hydrothermal reaction on the mixture to obtain an activated iron tailing mixture; (2) a surface modifier and the activated iron tailing mixture are mixed and stirred, and treated iron tailings are obtained; 3, the treated iron tailings and the acid and alkali resistant stabilizer aqueous solution are mixed and stirred, then aging, drying and calcining are conducted, and the silicon fertilizer is obtained.The preparation technology is simple, the raw material source is wide, and the prepared silicon fertilizer is high in effective silicon content, easy and convenient to use and capable of being applied to various agricultural crops.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization of iron ore resources, and specifically relates to a method for preparing silicon fertilizer using iron tailings. Background Technology

[0002] Silicon fertilizer is a high-quality fertilizer, a health-promoting fertilizer, and a plant regulator. Its main components include CaSiO3, Ca2SiO4, Mg2SiO4, and Ca3Mg(SiO4)2, and it has been recognized by the international soil science community as the fourth essential growth element fertilizer after nitrogen, potassium, and phosphorus. Large areas of my country have silicon-deficient soils, indicating a significant potential demand for silicon in agricultural production. Currently, silicon fertilizers sold on the market are basically divided into two categories: solid silicon fertilizer and liquid silicon fertilizer. Solid silicon fertilizer mainly consists of industrial silicon-containing waste residue; its effective silicon content is low, resulting in poor crop absorption, and long-term use can cause soil compaction. Liquid silicon fertilizer mainly consists of organosilicon, and its application is limited due to its high price.

[0003] Iron tailings contain a high amount of silica and are a type of solid waste left over from mineral processing. Utilizing the silica in iron tailings not only realizes the resource utilization of valuable components in solid waste and plays an important role in environmental protection, but also provides a widely available and inexpensive raw material for the preparation of silicon fertilizer.

[0004] However, the existing methods for preparing silicon fertilizer from iron tailings are relatively complex and the effective silicon content of the resulting solid silicon fertilizer is low. Therefore, it is necessary to improve the methods for preparing silicon fertilizer from iron tailings. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the current technology for preparing solid silicon fertilizer from iron tailings, and to invent a method for preparing silicon fertilizer from iron tailings. The preparation process is simple, the raw materials are widely available, the prepared silicon fertilizer has a high effective silicon content, it is easy to use, and it can be applied to a variety of agricultural crops.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing silicon fertilizer using iron tailings includes the following steps:

[0008] Step 1) Mix the compound activator, water and iron tailings, stir, and then treat with ultrasound to obtain a mixture. Then, carry out a hydrothermal reaction of the mixture to obtain an activated iron tailings mixture; wherein, the weight ratio of compound activator to water is 0.1~0.3:1, and the weight ratio of (compound activator + water) to iron tailings is 0.5~3:1.

[0009] Step 2) Mix the surface modifier with the activated iron tailings mixture obtained in Step 1) at a weight ratio of 0.05~0.2:100, stir, and obtain the treated iron tailings.

[0010] Step 3) Mix the iron tailings treated in Step 2) with an aqueous solution of acid and alkali stabilizer with a mass concentration of 0.1-1wt% at a weight ratio of 20-80:100, and then age, dry and calcine to obtain silicon fertilizer.

[0011] Furthermore, in the above-mentioned method for preparing silicon fertilizer from iron tailings, the compound activator in step 1) is two or three of potassium hydroxide, calcium hydroxide, calcium oxide, and calcium carbonate.

[0012] Furthermore, in the above-mentioned method for preparing silicon fertilizer using iron tailings, the iron tailings particle size range in step 1) is: -200 mesh accounts for more than 70%;

[0013] Furthermore, in the above-mentioned method for preparing silicon fertilizer from iron tailings, the ultrasonic frequency of the ultrasonic treatment in step 1) is 35~40KHz and the time is 20~30 minutes.

[0014] Furthermore, in the above-mentioned method for preparing silicon fertilizer from iron tailings, the hydrothermal reaction temperature in step 1) is 80~120℃ and the time is 1~3h.

[0015] Furthermore, in the above method for preparing silicon fertilizer from iron tailings, the surface modifier in step 2) is one or both of sodium dodecylbenzenesulfonate and hexadecyltrimethylammonium bromide;

[0016] Furthermore, in the above-mentioned method for preparing silicon fertilizer from iron tailings, the acid and alkali stabilizer in step 3) is one or more of xanthan gum, guar gum, and sodium carboxymethyl cellulose.

[0017] Furthermore, in the above method for preparing silicon fertilizer from iron tailings, the aging time in step 3) is 2-4 hours;

[0018] Furthermore, in the above method for preparing silicon fertilizer from iron tailings, the drying temperature in step 3) is 90~130℃ and the time is 4~8h.

[0019] Furthermore, in the above-mentioned method for preparing silicon fertilizer from iron tailings, the calcination temperature in step 3) is 400~700℃ and the time is 1~4h.

[0020] Furthermore, the silicon fertilizer prepared by the above-mentioned method of using iron tailings has an effective silicon content of 21% to 24%, a moisture content of 1% to 3%, and a fineness of 90% to 93%.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] 1. This invention utilizes iron tailings to solve the problem of solid waste accumulation and pollution, turning waste into treasure, which is in line with the concept of green development.

[0023] 2. In this invention, a compound activator is used in conjunction with ultrasonic and hydrothermal synergistic activation, combined with surface modification and acid and alkali stabilization treatment. The process design is scientific, and the effective silicon content obtained reaches 21%~24%, and the product quality is stable.

[0024] 3. The reaction conditions of this invention are mild, the parameters such as temperature and time are easy to control, and the energy consumption is low, making it suitable for large-scale production.

[0025] 4. The product obtained by this invention has a moisture content of 1% to 3%, a fineness of 90% to 93%, excellent physical and chemical properties, and good application effect. Attached Figure Description

[0026] Figure 1 XRD pattern of silicon fertilizer prepared in Example 1. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments and comparative examples.

[0028] The iron tailings used in this invention were obtained from a beneficiation plant in Anshan. The specific composition of the iron tailings is as follows: iron content 15.52%, SiO2 60.25%, CaO 3.94%, MgO 2.52%, Al2O3 2.17%, and other trace components; particle size of -200 mesh accounts for 76.16%.

[0029] The chemical reagents described in the examples and comparative examples were all commercially available.

[0030] Example 1

[0031] A method for preparing silicon fertilizer using iron tailings includes the following steps:

[0032] (1) Weigh the compound activator calcium oxide and calcium carbonate in a mass ratio of 1:1, weigh the water in a mass ratio of 0.25:1, weigh the iron tailings in a mass ratio of (compound activator + water) to iron tailings in a mass ratio of 1.5:1, mix the compound activator, water and iron tailings, place them in a stirrer, stir at 800 r / min for 1 h, then treat with ultrasound at a frequency of 40 kHz for 0.5 h, and then hydrothermally react at 100℃ for 1.5 h to obtain activated iron tailings;

[0033] (2) Weigh guar gum and water at a weight ratio of 0.15:100, stir at 800 r / min for 1 h to obtain an acid and alkali stabilizer solution;

[0034] (3) Weigh sodium dodecylbenzenesulfonate and activated iron tailings at a weight ratio of 0.1:100 and place them in a stirrer. Stir at 1000 r / min for 1 h to obtain the treated iron tailings.

[0035] (4) The treated iron tailings and acid-alkali stabilizer solution were placed in a stirrer at a weight ratio of 80:100 and stirred at 1000 r / min for 3 h. Then, the mixture was aged for 2 h, dried in a drying oven at 110 °C for 5 h, and finally calcined in a muffle furnace at 500 °C for 1.5 h to obtain silicon fertilizer. Figure 1 The XRD pattern shows that the silicon fertilizer sample exhibits a broad characteristic peak around 30°, indicating a predominantly amorphous state. Its main components are Ca2Mg3(Si2O7) and Mg2Si5Al4O3. 18 H 14 A mixture.

[0036] According to the national agricultural industry standard (NY / T797-2004), the effective silicon content in the silicon fertilizer is 23.18%, the moisture content is 1.96%, and the fineness is 92.08% (passing through a 250µm sieve).

[0037] Examples 2-6

[0038] The methods for preparing silicon fertilizer in Examples 2-6 are similar to those in Example 1, except that the experimental conditions are different.

[0039] Comparative Example 1

[0040] Comparative Example 1 is similar to Example 3, except that no compound activator was used to activate the iron tailings.

[0041] Comparative Example 2

[0042] Comparative Example 2 is similar to Example 4, except that no acid and alkali stabilizers were added.

[0043] Comparative Example 3

[0044] Comparative Example 3 is similar to Example 6, except that no calcination treatment was performed.

[0045] The experimental conditions and measurement results for the preparation of silicon fertilizer in the examples and comparative examples are shown in Tables 1 and 2.

[0046] Table 1. Test conditions and results of the examples

[0047] serial number Types of compound activators The weight ratio of compound activator to water (Compound activator + water) to iron tailings weight ratio Hydrothermal reaction temperature (°C) Hydrothermal reaction time (h) Types of acid and alkali stabilizers acid and alkali stabilizer to water weight ratio Types of surface modifiers Surface modifier to activated iron tailings weight ratio Mass ratio of treated iron tailings to acid and alkali stabilizer solution Aging time (h) Drying temperature (°C) Drying time (h) Calcination temperature (°C) Calcination time (h) Effective silicon content (%) Moisture (%) Fineness (%) Example 1 Y+T 0.1:1 1.5:1 100 1.5 E 0.15:100 B 0.1:100 80:100 2 110 5 500 1.5 23.18 1.96 92.08 Example 2 G+T 0.15:1 0.5:1 80 1 H 0.65:100 X 0.05:100 20:100 2 90 4 400 1 21.64 2.87 90.72 Example 3 G+J 0.15:1 1:1 90 2 E 0.5:100 X 0.1:100 50:100 4 100 6 600 2 22.01 2.54 91.61 Example 4 Y+G 0.1:1 2:1 110 3 H+E 0.5:100 B 0.15:100 60:100 3 120 7 700 2.5 22.46 2.18 92.17 Example 5 T+Y+G 0.25:1 3:1 120 2.5 S 0.25:100 B+X 0.2:100 70:100 3.5 130 8 500 3.5 23.37 2.27 91.83 Example 6 J+Y+T 0.15:1 2.5:1 100 2 E+S 1:100 B 0.1:100 40:100 2.5 90 5 450 4 22.74 2.48 92.64

[0048] Table 2. Comparative Experiment Conditions and Test Results

[0049] serial number Types of compound activators The weight ratio of compound activator to water (Compound activator + water) to iron tailings weight ratio Hydrothermal reaction temperature (°C) Hydrothermal reaction time (h) Types of acid and alkali stabilizers acid and alkali stabilizer to water weight ratio Types of surface modifiers Surface modifier to activated iron tailings weight ratio Mass ratio of treated iron tailings to acid and alkali stabilizer solution Aging time (h) Drying temperature (°C) Drying time (h) Calcination temperature (°C) Calcination time (h) Effective silicon content (%) Moisture (%) Fineness (%) Comparative Example 1 - - - - - E 0.5:100 X 0.1:100 50:100 4 100 6 600 2 11.24 2.71 90.67 Comparative Example 2 T+J 0.1:1 2:1 110 3 - - B 0.15:100 - 3 120 7 700 2.5 15.46 2.84 90.27 Comparative Example 3 J+Y 0.25:1 2.5:1 100 2 E+S 1:100 B 0.1:100 40:100 2.5 90 5 - - 18.69 4.67 82.69

[0050] Note: The compound activation agents potassium hydroxide, calcium hydroxide, calcium oxide, and calcium carbonate are designated as J, G, Y, and T, respectively; the acid and alkali stabilizers xanthan gum, guar gum, and sodium carboxymethyl cellulose are designated as H, E, and S, respectively; and the surface modifiers sodium dodecylbenzene sulfonate and hexadecyltrimethylammonium bromide are designated as B and X, respectively.

Claims

1. A method for preparing silicon fertilizer using iron tailings, characterized in that, Includes the following steps: Step 1) Mix the compound activator, water and iron tailings, stir, and then treat with ultrasound to obtain a mixture. Then, carry out a hydrothermal reaction of the mixture to obtain an activated iron tailings mixture; wherein, the weight ratio of compound activator to water is 0.1~0.3:1, and the weight ratio of (compound activator + water) to iron tailings is 0.5~3:

1. Step 2) Mix the surface modifier with the activated iron tailings mixture obtained in Step 1) at a weight ratio of 0.05~0.2:100, stir, and obtain the treated iron tailings. Step 3) Mix the iron tailings treated in Step 2) with an aqueous solution of acid and alkali stabilizer with a mass concentration of 0.1-1wt% at a weight ratio of 20-80:100, and then age, dry and calcine to obtain silicon fertilizer.

2. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The compound activator in step 1) is two or three of potassium hydroxide, calcium hydroxide, calcium oxide, and calcium carbonate.

3. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The iron tailings particle size range in step 1) is: -200 mesh accounts for more than 70%.

4. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The ultrasonic treatment in step 1) has an ultrasonic frequency of 35~40KHz and a duration of 20~30 minutes.

5. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The hydrothermal reaction in step 1) is carried out at a temperature of 80~120℃ for 1~3 hours.

6. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The surface modifier in step 2) is one or both of sodium dodecylbenzenesulfonate and hexadecyltrimethylammonium bromide.

7. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The acid and alkali stabilizer in step 3) is one or more of xanthan gum, guar gum, and sodium carboxymethyl cellulose.

8. The method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, In step 3), the aging time is 2-4 hours; the drying temperature is 90-130℃ and the time is 4-8 hours; the calcination temperature is 400-700℃ and the time is 1-4 hours.

9. A method for preparing silicon fertilizer from iron tailings according to claim 1, characterized in that, The resulting silicon fertilizer has an effective silicon content of 21% to 24%, a moisture content of 1% to 3%, and a fineness of 90% to 93%.

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