CN116161989A - Silicon fertilizer prepared from rice hulls and preparation method thereof - Google Patents

Abstract

The invention discloses a silicon fertilizer prepared by using rice husks and a preparation method thereof, belonging to the technical field of fertilizer production. The preparation method is to firstly use dry rice husks to prepare rice husk powder, then further modify it, and finally prepare the obtained The modified rice husk powder and other raw materials are prepared into silicon fertilizer. The invention uses rice husk to prepare a silicon fertilizer with low cost and high effective silicon content. At the same time, it can transform a part of the fixed silicate in the soil into plant fertilizer Absorbable silicic acid avoids heavy metal pollution and environmental hazards caused by the application of silicon fertilizers.

Description

A kind of silicon fertilizer prepared from rice husk and preparation method thereof

technical field

The invention relates to the technical field of fertilizer production, in particular to a silicon fertilizer prepared from rice husks and a preparation method thereof.

Background technique

Rice hulls are agricultural solid wastes produced during rice processing. my country is the largest rice-growing country in the world, with a large output of rice husks and a wide range of sources, but the utilization rate is low. In my country's rice-producing areas, rice husks are generally discarded as waste. However, due to the hard surface and high silicon content of rice husk, it is not easy to be decomposed by bacteria, and the bulk density is small, the volume is large, and a large area is required for stacking, which is easy to cause environmental pollution. Therefore, the efficient resource utilization of rice husk has practical value. .

Silicon fertilizer is considered to be the fourth important crop fertilizer after nitrogen fertilizer, potassium fertilizer and phosphorus fertilizer. Silicon is the fourth largest mineral element. It is an ideal soil conditioner and plays a very important role in the growth of plants. It can enhance plant photosynthesis, thereby increasing the accumulation of nutrients, and at the same time improving the activity of plant roots and promoting root growth. Respiration and nutrient absorption, if silicon is in plant epidermal cells, it can enhance the strength of plant stems and effectively reduce lodging. However, although the silicon content in the soil is very high, the part of silicon that can be absorbed and utilized by crops, that is, the content of effective silicon is low. Most of the silicon is in a very stable crystalline and amorphous state in the soil, and its solubility is very low. It is difficult for plants to absorb and utilize, so silicon fertilizers are often used to provide the silicon nutrients needed by plants.

At present, the varieties of artificially synthesized silicon fertilizer mainly include citrate-soluble silicon fertilizer and water-soluble silicon fertilizer. The part of silicon that is soluble in acid in water and absorbed by plants can only be dissolved by the organic acid released by the plant. The process is very slow, and it may contain heavy metals, which will cause heavy metal pollution in long-term field applications, and the cost of ore is high. And Mineral reserves are limited and cannot meet the actual needs of agricultural production; the effective silicon of water-soluble silicon fertilizer is the part of silicon that is directly absorbed and utilized by plants after being dissolved in water. The production process is relatively complicated and the cost is high. At present, the effective silicon content in the two types of silicon fertilizers is relatively low. The silicon content in rice husk is about 10%-21%, which is a very valuable resource, and rice husk can be used to prepare silicon fertilizer needed for plant growth, but the effective silicon content of silicon fertilizer prepared by using rice husk in the prior art is low . Therefore, the present invention provides a low-cost silicon fertilizer with high effective silicon content prepared from rice husks, which avoids the problems of heavy metal pollution, environmental hazards and high cost caused by the application of silicon fertilizers prepared by traditional methods.

Contents of the invention

In view of this, the purpose of the present invention is to provide a kind of silicon fertilizer that adopts rice husk preparation and preparation method thereof, avoid the heavy metal pollution, environmental hazards and high cost that use the silicon fertilizer that traditional method prepares to cause, solve the effective silicon content of silicon fertilizer The problem of low and conversion utilization of some silicates in the soil that are difficult to be absorbed by plants.

The present invention solves the above technical problems by the following technical means:

A silicon fertilizer prepared from rice husks, comprising the following raw materials: 60-80 parts by mass of modified rice husk powder, 7-9 parts by mass of calcium lignosulfonate, 10-18 parts by mass of zeolite, and 12-20 parts by mass of potassium borate , 8-12 parts by mass of attapulgite powder, 2-5 parts by mass of zinc acetate.

Further, the preparation method of described silicon fertilizer is:

(1) Mix the pulverized zeolite and attapulgite powder into water, add calcium lignosulfonate after stirring evenly, and obtain a mixed solution after stirring;

(2) After heating the mixed solution to 200-300°C, add zinc acetate, stir and react for 1-3h, add potassium borate and modified rice husk powder after cooling to room temperature, adjust the pH of the reaction system to 6-7, and heat the solution again Concentrate and dry at 400-500°C, and finally pulverize and filter to obtain silicon fertilizer.

Further, the modified rice husk powder includes the following raw materials: 1-4 parts by mass of potassium permanganate, 14-20 parts by mass of rice husk powder, 0.5-2 parts by mass of polycarbonate powder, 2-5 parts by mass of cerium acetate, 1.5-4.8 parts by mass of silicate, 1-4 parts by mass of diethylenetriamine.

Further, the specific preparation steps of the modified rice husk powder are:

(1) Prepare potassium permanganate solution and cerium acetate solution, mix potassium permanganate solution and cerium acetate solution, add rice husk powder, after magnetic stirring for 2-4h, ultrasonic 0.5-1h, stand at room temperature for 10 -12h, wash, filter and dry, and dry to constant weight to obtain pretreated rice husk powder;

(2) After the pretreated rice husk powder is mixed with water, add silicate and polycarbonate powder to react for 8-12 hours, add diethylenetriamine, heat to 50°C-70°C and keep for 13h-15h, cool, and then After suction filtration, washing, drying and cooling, the modified rice husk powder is obtained.

Further, in the preparation step (1) of the modified rice husk powder, the concentration of the potassium permanganate solution is 0.2 mol/L, and the concentration of the cerium acetate solution is 0.1 mol/L.

The pyrolysis product of rice husk, silica, is used as a skeleton to increase the pore structure of rice husk powder. Potassium permanganate is added to oxidize rice husk powder, which enriches the oxygen-containing functional groups on the surface of rice husk powder. Adding cerium acetate into rice husk powder In the pores of the husk powder, cerium ions replace impurity atoms such as sodium ions and potassium ions in the rice husk powder. Cerium is a rare earth element that can enhance the adsorption capacity of rice husk powder to silicate. After the silicate improves the surface activity of the rice husk powder, it is bonded with the active group of the rice husk powder, so that the silicate is easily grafted on the surface of the rice husk powder. Diethylenetriamine is covalently bonded to the surface groups of rice husk powder, so that the rice husk powder is loaded with highly hydrophilic polyamino compounds, and the carbonate is easily hydrolyzed to produce carbonate ions in an acidic environment. The silicate reaction converts the silicate that cannot be absorbed by plants into silicic acid that can be absorbed by plants, which can appropriately reduce the number of times of applying silicon fertilizer, and also avoids the silicon in silicon fertilizer from being fixed into silicic acid to a certain extent. Salt

Further, the preparation method of the rice husk powder is as follows:

(1) After crushing dry rice husks as raw materials, add water to the stainless steel high-temperature reaction kettle, seal the reaction kettle after mixing evenly, put the reaction kettle into a constant temperature oven to heat, set the temperature at 200-240°C, wait for the temperature After heating up, keep it for 2-6 hours and then turn off the power to lower the temperature to room temperature;

(2) Suction filter the reaction mixture in the reactor to obtain a solid product, dry the collected solid product in an oven at 40° C. for 24 hours to constant weight, and then grind and pulverize the obtained product to be rice husk powder.

Further, the ratio of the dry rice husk to water is 1:10.

Further, the mixture produced by the reaction in the preparation step (2) of the rice husk powder is subjected to vacuum filtration with a filter membrane of 0.45 μm.

Beneficial effect:

The silicon fertilizer prepared by the present invention has the following advantages:

(1) The preparation method provided by the invention uses rice husk as a raw material and converts it into silicon fertilizer, thereby realizing resource utilization of waste;

(2) In the process of preparing rice husk powder, the present invention treats respectively at 220°C for 4h, 220°C for 4h, and 240°C for 2h, 4h, and 6h respectively, and it is obtained that when preparing rice husk powder, the treatment at 240°C The content of active silicon in the rice husk powder obtained at 6h was the highest, which was 133.55mg/kg.

(3) The obtained silicon fertilizer has high silicon content and extremely low content of harmful impurities such as heavy metal ions, which avoids its poisoning and environmental hazards. In addition, since the hydrothermal carbon-based silicon fertilizer is easier for crops to absorb, the application can improve crop quality The prepared silicon fertilizer can interact with the silicate in the soil to convert the invalid silicon in the soil into effective silicon, instead of simply relying on artificial addition of silicon.

Instructions attached

Fig. 1: the effective silicon content of rice husk powder after the reaction of embodiment 1-5;

Fig. 2: the growth figure of ryegrass after applying the silicon fertilizer prepared by embodiment 6;

Fig. 3: the growth figure of ryegrass after applying the silicon fertilizer prepared by embodiment 5;

Fig. 4: Growth chart of ryegrass after applying the silicon fertilizer prepared in Comparative Example 5.

Detailed ways

The present invention will be described in detail below in conjunction with embodiment and accompanying drawing:

The present invention provides a silicon fertilizer prepared from rice husk and a preparation method thereof, but rice husk powder needs to be prepared earlier, and the specific preparation steps of the rice husk powder prepared by the present invention are as follows:

Embodiment 1: the preparation one of rice husk powder

The rice husk powder that present embodiment adopts can be prepared by following steps:

(1) After crushing 1 kg of dry rice husk as a raw material, add the dry rice husk and water into the stainless steel high-temperature reaction kettle at a ratio of 1:10, and seal the reaction kettle after mixing evenly; put the reaction kettle into a constant temperature oven to heat, Set the temperature to 200°C. After the temperature rises to 200°C, keep it for 4 hours, turn off the power, and lower the temperature to room temperature;

(2) The mixture produced by the reaction in the reactor is vacuum filtered with a filter membrane of 0.45 μm to obtain a solid phase product, and the collected solid phase product is dried in an oven at 40°C for 24 hours to constant weight, and the obtained solid product is Rice husk powder.

Embodiment 2: the preparation two of rice husk powder

(1) After crushing 1 kg of dry rice husk as a raw material, add the dry rice husk and water into the stainless steel high-temperature reaction kettle at a ratio of 1:10, and seal the reaction kettle after mixing evenly; put the reaction kettle into a constant temperature oven to heat, Set the temperature to 220°C. After the temperature rises to 220°C, keep it for 4 hours, turn off the power, and lower the temperature to room temperature;

(2) The mixture produced by the reaction in the reactor is vacuum filtered with a filter membrane of 0.45 μm to obtain a solid phase product, and the collected solid phase product is dried in an oven at 40°C for 24 hours to constant weight, and the obtained solid product is Rice husk powder.

Embodiment 3: Preparation three of rice husk powder

(1) After crushing 1 kg of dry rice husk as a raw material, add the dry rice husk and water into the stainless steel high-temperature reaction kettle at a ratio of 1:10, and seal the reaction kettle after mixing evenly; put the reaction kettle into a constant temperature oven to heat, Set the temperature to 240°C. After the temperature rises to 240°C, keep it for 2 hours, turn off the power, and lower the temperature to room temperature;

(2) The mixture produced by the reaction in the reactor is vacuum filtered with a filter membrane of 0.45 μm to obtain a solid phase product, and the collected solid phase product is dried in an oven at 40°C for 24 hours to constant weight, and the obtained solid product is Rice husk powder.

Embodiment 4: Preparation four of rice husk powder

(1) After crushing 1 kg of dry rice husk as a raw material, add the dry rice husk and water into the stainless steel high-temperature reaction kettle at a ratio of 1:10, and seal the reaction kettle after mixing evenly; put the reaction kettle into a constant temperature oven to heat, Set the temperature to 240°C. After the temperature rises to 240°C, keep it for 4 hours, turn off the power, and lower the temperature to room temperature;

(2) The mixture produced by the reaction in the reactor is vacuum filtered with a filter membrane of 0.45 μm to obtain a solid phase product, and the collected solid phase product is dried in an oven at 40°C for 24 hours to constant weight, and the obtained solid product is Rice husk powder.

Embodiment 5: Preparation five of rice husk powder

(1) After crushing 1 kg of dry rice husk as a raw material, add the dry rice husk and water into the stainless steel high-temperature reaction kettle at a ratio of 1:10, and seal the reaction kettle after mixing evenly; put the reaction kettle into a constant temperature oven to heat, Set the temperature to 240°C. After the temperature rises to 240°C, keep it for 6 hours, turn off the power, and lower the temperature to room temperature;

(2) The mixture produced by the reaction in the reactor is vacuum filtered with a filter membrane of 0.45 μm to obtain a solid phase product, and the collected solid phase product is dried in an oven at 40°C for 24 hours to constant weight, and the obtained solid product is Rice husk powder.

After testing the active silicon content of the rice husk powder prepared in Examples 1-5, it was found that the active silicon content of the rice husk powder prepared at 240° C. for 6 hours (Example 5) was the highest, as shown in Table 1.

Table 1: The effective silicon content of rice husk powder after the reaction of Examples 1-5

group Effective silicon content (mg/kg) Example 1 99.55 Example 2 107.38 Example 3 102.24 Example 4 122.73 Example 5 133.55

Embodiment 6: the preparation one of silicon fertilizer

In this embodiment, modified rice husk powder needs to be prepared before silicon fertilizer is prepared. The modified rice husk powder used takes raw materials according to the following quality, wherein the rice husk powder adopts the rice husk powder prepared in Example 5:

Preparation of modified rice husk powder:

Weigh 3kg of potassium permanganate, 17kg of rice husk powder, 1.5kg of polycarbonate powder, 3kg of cerium acetate, 3.2kg of silicate, and 3kg of diethylenetriamine.

(1) prepare 0.2mol/L potassium permanganate solution and 0.1mol/L cerium acetate solution, add the rice husk powder prepared in Example 5 after potassium permanganate solution and cerium acetate solution are mixed, after magnetic stirring 3h, Ultrasound for 1 hour, stand at room temperature for 11 hours, wash, filter and dry at room temperature, and dry to constant weight to obtain pretreated rice husk powder;

(2) Mix the pretreated rice husk powder with water, add silicate and polycarbonate powder to react for 10 hours, add diethylenetriamine, heat to 60°C and keep for 14 hours, cool, and sequentially suction filter, wash, dry, After cooling, the modified rice husk powder is obtained.

Preparation of silicon fertilizer:

Weigh 70kg of modified rice husk powder, 8kg of calcium lignosulfonate, 14kg of zeolite, 16kg of potassium borate, 10kg of attapulgite powder, and 3kg of zinc acetate.

(1) Mix the pulverized zeolite and attapulgite powder into water, stir evenly at 198r/min, then add calcium lignosulfonate, and stir to obtain a mixed solution;

(2) Add zinc acetate after heating the mixed solution to 250°C, stir for 2 hours, add potassium borate and modified rice husk powder after cooling to normal temperature, adjust the pH of the reaction system to 6.5, heat the solution again to 450°C for concentration and Dry, and finally crush and filter to obtain silicon fertilizer.

Embodiment 7: the preparation two of silicon fertilizer

Preparation of modified rice husk powder:

Weigh 1kg of potassium permanganate, 14kg of rice husk powder, 0.5kg of polycarbonate powder, 2kg of cerium acetate, 1.5kg of silicate, and 1kg of diethylenetriamine.

(1) prepare 0.2mol/L potassium permanganate solution and 0.1mol/L cerium acetate solution, add the rice husk powder prepared in Example 5 after potassium permanganate solution and cerium acetate solution are mixed, after magnetic stirring 2h, Ultrasound for 0.5h, stand at room temperature for 10h, wash, filter and dry at room temperature, and dry to constant weight to obtain pretreated rice husk powder;

(2) Mix the pretreated rice husk powder with water, add silicate and polycarbonate powder to react for 8 hours, add diethylenetriamine, heat to 50°C and keep for 15 hours, cool, and sequentially suction filter, wash, dry, After cooling, the modified rice husk powder is obtained.

Preparation of silicon fertilizer:

Weigh 60kg of modified rice husk powder, 7kg of calcium lignosulfonate, 10kg of zeolite, 12kg of potassium borate, 8kg of attapulgite powder, and 2kg of zinc acetate.

(1) Mix the pulverized zeolite and attapulgite powder into water, stir evenly at 198r/min, then add calcium lignosulfonate, and stir to obtain a mixed solution;

(2) Add zinc acetate after heating the mixed solution to 200°C, stir and react for 3 hours, add potassium borate and modified rice husk powder after cooling to normal temperature, adjust the pH of the reaction system to 7, heat the solution again to 500°C for concentration and Dry, and finally crush and filter to obtain silicon fertilizer.

Embodiment 8: Preparation three of silicon fertilizer

Preparation of modified rice husk powder:

Weigh 4kg of potassium permanganate, 20kg of rice husk powder, 2kg of polycarbonate powder, 5kg of cerium acetate, 4.8kg of silicate, and 4kg of diethylenetriamine.

(1) prepare 0.2mol/L potassium permanganate solution and 0.1mol/L cerium acetate solution, add the rice husk powder prepared in Example 5 after potassium permanganate solution and cerium acetate solution are mixed, after magnetic stirring 4h, Ultrasound for 1 hour, let stand at room temperature for 12 hours, wash, filter and dry at room temperature, and dry to constant weight to obtain pretreated rice husk powder;

(2) Mix the pretreated rice husk powder with water, add silicate and polycarbonate powder to react for 12 hours, add diethylenetriamine, heat to 70°C and keep for 13 hours, cool, and sequentially suction filter, wash, dry, After cooling, the modified rice husk powder is obtained.

Preparation of silicon fertilizer:

Weigh 80kg of modified rice husk powder, 9kg of calcium lignosulfonate, 18kg of zeolite, 20kg of potassium borate, 12kg of attapulgite powder, and 5kg of zinc acetate.

(1) Mix the pulverized zeolite and attapulgite powder into water, stir evenly at 198r/min, then add calcium lignosulfonate, and stir to obtain a mixed solution;

(2) Add zinc acetate after heating the mixed solution to 300°C, stir and react for 1 hour, add potassium borate and modified rice husk powder after cooling to normal temperature, adjust the pH of the reaction system to 6, heat the solution again to 400°C for concentration and Dry, and finally crush and filter to obtain silicon fertilizer.

Comparative example 1: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6, and its main difference is that the rice husk powder is not processed by adding cerium acetate in the preparation process of step (1) when preparing the modified rice husk powder , all the other raw material ratios and steps are the same as those in Example 6, and the specific preparation steps are as follows:

Preparation of modified rice husk powder:

(1) prepare 0.2mol/L potassium permanganate solution, add the rice husk powder prepared in Example 5 to the potassium permanganate solution, after magnetic stirring for 3 hours, ultrasonication for 1 hour, let stand at room temperature for 11 hours, wash and filter and Drying at normal temperature until the constant weight is obtained to obtain the pretreated rice husk powder.

Preparation of silicon fertilizer:

The modified rice husk powder used is the modified rice husk powder prepared above, and the rest of the steps and raw materials are the same as the preparation of the silicon fertilizer in Example 6.

Comparative example 2: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6, and its main difference is that no polycarbonate powder is added to the rice husk powder in the preparation process of step (2) when preparing the modified rice husk powder. Process, all the other raw material ratios and steps are the same as those of Example 6, and the specific preparation steps are as follows:

Preparation of modified rice husk powder:

(2) Mix the pretreated rice husk powder with water, add silicate to react for 10 hours, add diethylenetriamine, heat to 60°C and keep for 14 hours, cool, suction filter, wash, dry, and cool in sequence to obtain the improved Sexual rice husk powder.

Preparation of silicon fertilizer:

The modified rice husk powder used is the modified rice husk powder prepared above, and the rest of the steps and raw materials are the same as the preparation of the silicon fertilizer in Example 6.

Comparative example 3: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6. The main difference is that diethylenetriamine is not added to the rice husk powder in the preparation process of step (2) when preparing the modified rice husk powder. Process, all the other raw material ratios and steps are the same as those of Example 6, and the specific preparation steps are as follows:

Preparation of modified rice husk powder:

(2) Mix pretreated rice husk powder with water, add silicate and polycarbonate powder to react for 10 hours, then cool, suction filter, wash, dry, and cool in sequence to obtain modified rice husk powder.

Preparation of silicon fertilizer:

The modified rice husk powder used is the modified rice husk powder prepared above, and the rest of the steps and raw materials are the same as the preparation of the silicon fertilizer in Example 6.

Comparative example 4: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6. The main difference is that the modified rice husk powder lacks step (1), that is, the rice husk powder is directly processed without a pretreatment step. Modification, all the other raw material ratios and steps are the same as those in Example 6, and the specific preparation steps are as follows:

Preparation of modified rice husk powder:

(1) Mix the rice husk powder prepared in Example 5 with water, add silicate and polycarbonate powder to react for 10 hours, add diethylenetriamine, heat to 60°C and keep for 14 hours, cool, suction filter and wash successively , drying and cooling to obtain the modified rice husk powder.

Preparation of silicon fertilizer:

The modified rice husk powder used is the modified rice husk powder prepared above, and the rest of the steps and raw materials are the same as the preparation of the silicon fertilizer in Example 6.

Comparative example 5: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 5, and its main difference is that when preparing modified rice husk powder, it lacks step (2), that is, the rice husk powder is not subjected to secondary modification, Directly prepare silicon fertilizer after pretreatment, all the other raw material ratios are identical with the raw material ratio of embodiment 5, and concrete preparation steps are as follows:

Preparation of modified rice husk powder:

(1) prepare 0.2mol/L potassium permanganate solution and 0.1mol/L cerium acetate solution, add the rice husk powder prepared in Example 5 after the potassium permanganate solution is mixed with the cerium acetate solution, after magnetic stirring for 3h, ultrasonic 1h, stand at room temperature for 11h, wash and filter and dry at room temperature, and dry to constant weight to obtain pretreated rice husk powder;

Preparation of silicon fertilizer:

The modified rice husk powder used is the modified rice husk powder prepared above, and the rest of the steps and raw materials are the same as the preparation of the silicon fertilizer in Example 6.

Comparative example 6: Preparation of silicon fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6. The main difference is that no modified rice husk powder is used, only the rice husk powder prepared in Example 5 is used, and the ratio of the remaining raw materials and steps The raw material proportioning and step are identical with embodiment 6.

Comparative Example 7: Preparation of Silicon Fertilizer

The silicon fertilizer prepared in this comparative example is compared with the silicon fertilizer prepared in Example 6. The main difference is that no modified rice husk powder is used, only activated carbon is used, and the ratio and steps of the remaining raw materials are the same as those in Example 6. The ratio is the same as the steps.

Experiment 1: Test of effective silicon content in silicon fertilizer

Select the silicon fertilizers prepared in Example 6 and Comparative Examples 1-7, each get 5g small samples, test the effective silicon content in the silicon fertilizers prepared by each group with reference to the national standard "NY/T797-2004", set a blank control group in addition, blank For the control group, the conditions were the same except that no sample was added, and each was repeated three times.

The test steps are as follows:

(1) Preparation of sample solution: Weigh about 1g of each group of samples, place them in a 250mL dry stoppered Erlenmeyer flask or volumetric flask, accurately add 150mL of 0.5mol/L hydrochloric acid solution preheated to 28°C, and stopper the bottle tightly. Plug and shake; use a 30r/min up and down rotary shaker, keep the solution temperature at 28°C-30°C, and shake for 1h. Immediately after shaking, filter with a dry funnel and fast filter paper, and discard the first few milliliters of filtrate.

(2) Determination of content: Accurately draw 50mL of filtrate into an evaporating dish, add 40mL of saturated boric acid solution of hydrochloric acid and mix well, evaporate on a water bath to nearly dryness, add 40mL of hydrochloric acid, 20mL of 20g/L animal glue solution, and dissolve at 70 ℃-80℃ water bath for 30min to dissolve and condense silica. Use the pouring method for the precipitation, filter the precipitation with quantitative filter paper, wash the evaporating dish and the precipitation with warm hydrochloric acid solution 4-6 times each, and use about 5mL-10mL each time, then wash the evaporating dish and the precipitation with hot water, each time Wash with about 10mL of water until there is no chloride ion, and test with 10g/L silver nitrate solution;

Put the precipitate together with the filter paper into a platinum crucible, place the platinum crucible on an electric furnace lined with asbestos mesh, dry it carefully, and place it in a muffle furnace after the ashing is complete. Burn at 950°C for 1h. Take it out and cool it slightly, put it in a desiccator to cool for 30min, and weigh it. Add a few drops of water to the platinum crucible to moisten the precipitate, add 2 drops of sulfuric acid solution, and 3mL of hydrofluoric acid. Place the platinum crucible on an electric furnace lined with asbestos net and heat slowly until the sulfuric acid emits white smoke, and continue heating to evaporate to nearly dryness. Remove the platinum crucible and cool it to room temperature, then add 5mL of hydrofluoric acid, continue heating until the white smoke of sulfur trioxide is exhausted, transfer it into a muffle furnace, and burn at 950°C for 1h. Take it out and cool it slightly, place it in a desiccator to cool for 30min, and weigh it.

Among them, the effective silicon content (SiO ₂ ) is represented by mass fraction W(SiO ₂ ):

W＝100×[(m ₁ -m ₂ )-(m ₃ -m ₄ )]/(m×50÷150)

m ₁ (g)-the mass of precipitation and platinum crucible before hydrofluoric acid treatment;

m ₂ (g)-the mass of precipitate and platinum crucible after hydrofluoric acid treatment;

m ₃ (g)-the mass of the precipitate and platinum crucible before hydrofluoric acid treatment in the blank test;

m ₄ (g) - the weight of the precipitate and platinum crucible after hydrofluoric acid treatment in the blank test;

m-sample mass (g)

Table 1

group Effective silicon content/(%) Example 6 83.60 Comparative example 1 75.28 Comparative example 2 71.15 Comparative example 3 67.04 Comparative example 4 74.57 Comparative example 5 71.12 Comparative example 6 67.41 Comparative example 7 55.90 blank control 34.95

Experiment 2: Growth status of ryegrass

Perennial ryegrass seeds with full grains, no pests, and the same size were selected for growth test after disinfection, and 1.2 kg of soil was accurately weighed in a flower pot. Every group of 100 seeds, the seeds were respectively mixed with the silicon fertilizers prepared in Example 6 and Comparative Examples 1-7, and evenly planted in flower pots. After the seeds emerged, they were watered quantitatively, and the potted plants were placed in a greenhouse and exposed to light. For 16 hours, the temperature was (26±2)°C, in the dark for 8 hours, the temperature was (24±2)°C, and the relative humidity was 70%. Adjust the moisture with deionized water, and regularly supplement the soil moisture according to the weighing method to keep the soil moisture constant. Repeated 3 times, the ryegrass was harvested at the 4th week after sowing, and the results are shown in Table 2.

Table 2

group Plant height (cm) root length (cm) Example 6 34.25 19.56 Comparative example 1 30.60 18.87 Comparative example 2 28.27 16.81 Comparative example 3 29.23 18.04 Comparative example 4 28.74 17.12 Comparative example 5 27.98 16.03 Comparative example 6 27.56 14.01 Comparative example 7 26.03 13.45 blank control 21.33 10.64

It can be obtained from Table 1-Table 2:

1, the silicon fertilizer that embodiment 6 prepares detects that the content of available silicon is 83.60%, and uses the silicon fertilizer that embodiment 6 prepares to cultivate the ryegrass that obtains for four weeks in experiment two, and plant height is 34.25cm, and root length is 19.56cm, illustrates The silicon fertilizer prepared according to the ratio of raw materials and the method disclosed in the invention has a high content of active silicon, can be directly absorbed and utilized by plants, and has the best effect of promoting the growth of ryegrass.

2. The effective silicon content of Comparative Example 1 is reduced by 8.32% compared with Example 6. The plant height of ryegrass is 30.60cm, and the root length is 18.87cm. Raw material cerium acetate is not added in the pretreatment, and the adsorption of rice husk powder to silicate The capacity is weakened, the silicate cannot be well adsorbed, and it is difficult to convert the silicate in the subsequent reaction. Comparative Example 2 The effective silicon content is 71.15%, the plant height of ryegrass is 28.27cm, and the root length is 16.81cm. The raw material polycarbonate is not added in the pretreatment, and the carbonate ion and silicate reaction cannot be hydrolyzed to generate the required plant. silicic acid, the available silicon available to plants is only provided by the silicon fertilizer, so the effect is poorer than that of Example 6.

3. The effective silicon content of Comparative Example 3 is 16.56% less than that of Example 5. The plant height of ryegrass is 29.23cm, and the root length is 18.04cm. No raw material diethylenetriamine is added in the modification; the effective silicon ratio of Comparative Example 4 The content of embodiment 5 is less than 9.03%. The plant height of ryegrass is 28.74cm, and the root length is 17.12cm. The rice husk powder is not pretreated, and the oxygen-containing functional groups on the surface are less. The amount of shell powder surface is reduced, and cerium acetate modification is not introduced. The effective silicon content of comparative example 5 is 71.12%, the plant height of ryegrass is 27.98cm, the root length is 16.03cm, the rice husk powder is not modified, the surface activity is poor, and the original silicon in the soil cannot be converted.

4. The effective silicon contents of Comparative Example 6 and Comparative Example 7 were 67.41% and 55.90% respectively, the plant heights of ryegrass were 27.56cm and 26.03cm respectively, and the root lengths were 14.01cm and 13.45cm respectively, compared with the blank control group , the two groups have a certain influence on the growth of ryegrass, but the available silicon is insufficient, and they only play the role of general fertilizer.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solutions of the present invention, all of them should be included in the scope of the claims of the present invention. The technologies, shapes and construction parts not described in detail in the present invention are all known technologies.

Claims (8)

1. A silicon fertilizer prepared from rice husk is characterized in that the silicon fertilizer comprises the following raw materials: 60-80 parts by mass of modified rice husk powder, 7-9 parts by mass of calcium lignosulfonate, 10-18 parts by mass Parts of zeolite, 12-20 parts by mass of potassium borate, 8-12 parts by mass of attapulgite powder, and 2-5 parts by mass of zinc acetate. 2. a kind of preparation method of the silicon fertilizer that adopts rice husk preparation is characterized in that, the preparation method of described silicon fertilizer is: (1) Mix the pulverized zeolite and attapulgite powder into water, add calcium lignosulfonate after stirring evenly, and obtain a mixed solution after stirring; (2) After heating the mixed solution to 200-300°C, add zinc acetate, stir and react for 1-3h, add potassium borate and modified rice husk powder after cooling to room temperature, adjust the pH of the reaction system to 6-7, and heat the solution again Concentrate and dry at 400-500°C, and finally pulverize and filter to obtain silicon fertilizer. 3. a kind of preparation method of the silicon fertilizer that adopts rice husk to prepare according to claim 2 is characterized in that, described modified rice husk powder comprises following raw material: 1-4 mass parts potassium permanganate, 14-20 Parts by mass of rice husk powder, 0.5-2 parts by mass of polycarbonate powder, 2-5 parts by mass of cerium acetate, 1.5-4.8 parts by mass of silicate, and 1-4 parts by mass of diethylenetriamine. 4. a kind of preparation method of the silicon fertilizer that adopts rice husk preparation according to claim 3 is characterized in that, the concrete preparation steps of described modified rice husk powder are: (1) Prepare potassium permanganate solution and cerium acetate solution, mix potassium permanganate solution and cerium acetate solution, add rice husk powder, after magnetic stirring for 2-4h, ultrasonic 0.5-1h, stand at room temperature for 10 -12h, wash, filter and dry, and dry to constant weight to obtain pretreated rice husk powder; (2) Mix pretreated rice husk powder and water, add silicate and polycarbonate powder to react for 8-12 hours, add diethylenetriamine, heat to 50°C-70°C and keep for 13h-15h, cool, and then After suction filtration, washing, drying and cooling, the modified rice husk powder is obtained. 5. a kind of preparation method of the silicon fertilizer that adopts rice husk preparation according to claim 4 is characterized in that, the concentration of potassium permanganate solution in the preparation step (1) of described modified rice husk powder is 0.2mol/ L, the concentration of cerium acetate solution is 0.1mol/L. 6. a kind of preparation method of the silicon fertilizer that adopts rice husk preparation according to claim 4 is characterized in that, the preparation method of described rice husk powder is as follows: (1) After crushing dry rice husks as raw materials, mix them evenly with water and heat them. Set the temperature at 200-240°C. After the temperature rises, keep it for 2-6 hours and then turn off the power to lower the temperature to room temperature; (2) Suction filter the reaction mixture in the reactor to obtain a solid product, dry the collected solid product in an oven at 40° C. for 24 hours to constant weight, and then grind and pulverize the obtained product to be rice husk powder. 7. a kind of preparation method of the silicon fertilizer that adopts rice husk to prepare according to claim 6 is characterized in that, the mass ratio of described dry rice husk and water is 1:10. 8. a kind of preparation method of the silicon fertilizer that adopts rice husk preparation according to claim 6 is characterized in that, the mixture that reacts in the preparation step (2) of described rice husk powder adopts the filter membrane of 0.45 μm to carry out vacuum Suction.

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