Conditioner for improving acid soil and preparation method thereof

Abstract

The invention discloses a conditioner for improving acid soil and a preparation method thereof, dolomite, bentonite and a sodium alginate solution are mixed according to a certain proportion, acidified dolomite is used as a cross-linking agent to form small balls, and the small balls are washed with deionized water and dried to obtain the soil conditioner. According to the method, the natural dolomite is used as a main raw material for improving the acid soil and is also used as a raw material of a cross-linking agent, so that Ca < 2 + > in the dolomite and sodium alginate form a structure with a three-dimensional cross-linked network and pores through electrostatic interaction; the soil conditioner can improve the acid environment of soil, doubly adjust the pH value of the soil and increase nutrient elements such as Ca and Mg in the soil, and the preparation method is simple, green and safe.

Description

Technical Field

[0001] The invention belongs to the technical field of soil improvement, and in particular relates to a conditioner for improving acidic soil and a preparation method thereof. Background Art

[0002] The essence of soil acidification is the change in the chemical properties of the soil itself. The most direct manifestation of soil acidification is the decrease in soil pH. As the soil pH value decreases, the release of different forms of aluminum ions in the soil will increase toxicity to plants, and will also promote the leaching of basic ions such as calcium and magnesium, leading to a decrease in soil fertility, which seriously affects the yield and quality of crops.

[0003] Soil conditioners have gained wide attention and application due to their advantages such as simple operation and significant effects. Among the existing conditioners for improving acidic soil, organic material conditioners can adjust the soil microbial community and quantity, but harmful microorganisms such as pathogenic microorganisms and parasite eggs increase, making it difficult to promote their use; industrial waste and by-product conditioners are prone to cause heavy metal pollution in the soil, leading to secondary pollution; the production cost of some new conditioners is high, which limits their large-scale application. At present, the most common method to improve acidic soil is to directly spread lime, but improper use will lead to soil eutrophication.

[0004] Sodium alginate is widely available, inexpensive, and highly safe. It is biodegradable, easy to handle, and easy to mass-produce. It is used as an embedding material to protect and transport agricultural beneficial substances. Bentonite has the advantages of electronegativity, good water absorption and swelling, adhesion, and environmental friendliness. It is also rich in macro- and trace elements required by plants and animals. It can effectively adjust the soil structure, increase soil water storage capacity, and the content and stability of large aggregates. Dolomite is a carbonate mineral crystallized in equal proportions of magnesium carbonate and calcium carbonate. It can effectively increase soil pH and increase the effectiveness of nutrients such as Ca and Mg in the soil. In addition, after acidification of dolomite, Ca 2+ It can be used as a cross-linking agent to cross-link with sodium alginate to obtain a soil conditioner with a three-dimensional cross-linked network and pore structure.

[0005] At present, there are no reports on using sodium alginate to embed inorganic minerals and acidified dolomite as a cross-linking agent to improve acidic soil. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a conditioner for improving acidic soil and a preparation method thereof. The present invention uses sodium alginate to embed dolomite and bentonite, and uses acidified dolomite as a cross-linking agent to obtain a composite stable, green, safe, simple and convenient conditioner for improving acidic soil.

[0007] The technical solution of the present invention is as follows:

[0008] A conditioner for improving acidic soil is prepared according to the following method:

[0009] (1) Grinding and sieving natural dolomite (200 mesh), placing it in a muffle furnace, heating it to 800-1000° C. and maintaining it for 3-5 hours to obtain calcined dolomite; dissolving the calcined dolomite in deionized water to obtain dolomite ash emulsion;

[0010] The preferred heating rate during calcination is 5°C / min;

[0011] The preferred mass ratio of calcined dolomite to deionized water is 2.5:12.5-75;

[0012] (2) adding natural dolomite to a hydrochloric acid solution, stirring (1 h), filtering (removing dolomite residue), adding the dolomite emulsion obtained in step (1) to the filtrate to adjust the pH to neutral, filtering, and diluting the filtrate with deionized water to obtain an acidified dolomite cross-linking agent;

[0013] The preferred mass fraction of hydrochloric acid solution is 37%;

[0014] Preferably, the molar ratio of natural dolomite to hydrochloric acid is 1:4;

[0015] Dolomite emulsion was used as a pH regulator to adjust the pH of the filtrate obtained from the first filtration to neutral, and the Al in the filtrate was 3+ , Fe 3+ Converted into Al(OH)3 and Fe(OH)3, which are removed during the second filtration;

[0016] The preferred feed ratio of natural dolomite and deionized water (for dilution) is 20:50-200, g / mL;

[0017] (3) mixing sodium alginate and deionized water, stirring and dispersing them uniformly to obtain a sodium alginate solution;

[0018] The preferred mass fraction of the sodium alginate solution is 1%;

[0019] (4) adding natural dolomite and bentonite to the sodium alginate solution obtained in step (3) in sequence and mixing them to obtain a mixed slurry;

[0020] The preferred mass ratio of natural dolomite to bentonite is 0-4:2-6;

[0021] Preferably, the mass ratio of the total mass of natural dolomite and bentonite to the mass ratio of sodium alginate is 6:1;

[0022] (5) pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent obtained in step (2) by a peristaltic pump, soaking and molding, washing (with deionized water), and drying to obtain the conditioner for improving acidic soil;

[0023] The preferred volume ratio of the mixed slurry to the acidified dolomite cross-linking agent is 100:50-200;

[0024] The preferred immersion molding time is 3 to 24 hours.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] In the present invention, sodium alginate embeds natural dolomite and bentonite, which increases the stability of sodium alginate and allows natural dolomite and bentonite to be slowly released, thereby improving the acidic environment of the soil. Natural dolomite is not only used as the main raw material of the acidic soil conditioner, but also as the raw material of the cross-linking agent, so that the Ca in the dolomite 2+ It is fully cross-linked with sodium alginate to obtain a soil conditioner with a three-dimensional cross-linked network and a pore structure, which can dually adjust the soil pH and increase soil nutrients such as Ca and Mg. The soil conditioner is composite, stable, green and safe, and has a simple preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : The soil conditioner of embodiment 2. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the subject matter and scope of the present invention as described above, but these modifications and replacements all fall within the scope of protection of the present invention.

[0029] In the embodiments of the present invention:

[0030] The pH value of the soil was tested according to HJ 962-2018 "Potential method for determination of soil pH value".

[0031] The calcium and magnesium content in the soil was tested according to NY / T1121.13-2006 "Soil Testing Part 13: Determination of Exchangeable Calcium and Magnesium in Soil".

[0032] Acidic red soil was collected from the farmland of Jiuchang Village, Suixi County, Zhanjiang City, Guangdong Province.

[0033] Example 1

[0034] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 12.5 g of deionized water to obtain dolomite ash;

[0035] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 50 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0036] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0037] (4) Weighing 2 g of natural dolomite and 4 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0038] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0039] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.45, exchangeable calcium 1257 mg / kg, and exchangeable magnesium 198 mg / kg.

[0040] Example 2

[0041] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 12.5 g of deionized water to obtain dolomite ash;

[0042] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 50 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0043] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0044] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0045] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0046] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.65, exchangeable calcium 1497 mg / kg, and exchangeable magnesium 349 mg / kg.

[0047] Example 3

[0048] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 12.5 g of deionized water to obtain dolomite ash;

[0049] (2) adding 20 g of natural dolomite to 36.27 ml of 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the mixed dolomite emulsion in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 50 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0050] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0051] (4) Weighing 3.6 g of natural dolomite and 2.4 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0052] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0053] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.65, exchangeable calcium 1376 mg / kg, and exchangeable magnesium 278 mg / kg.

[0054] Example 4

[0055] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 12.5 g of deionized water to obtain dolomite ash;

[0056] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 50 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0057] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0058] (4) Weighing 4 g of natural dolomite and 2 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0059] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0060] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.65, exchangeable calcium 1293 mg / kg, and exchangeable magnesium 238 mg / kg.

[0061] Example 5

[0062] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 12.5 g of deionized water to obtain dolomite ash;

[0063] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 50 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0064] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0065] (4) Weigh 6 g of bentonite and add the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0066] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0067] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1267 mg / kg, and exchangeable magnesium 224 mg / kg.

[0068] Example 6

[0069] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 900° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 25 g of deionized water to obtain dolomite ash;

[0070] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 100 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0071] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0072] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0073] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0074] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1417 mg / kg, and exchangeable magnesium 303 mg / kg.

[0075] Example 7

[0076] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 900° C. at a heating rate of 5° C. / min and calcined for 3 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 25 g of deionized water to obtain dolomite ash emulsion;

[0077] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0078] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0079] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0080] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0081] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1421 mg / kg, and exchangeable magnesium 288 mg / kg.

[0082] Example 8

[0083] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 900° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 50 g of deionized water to obtain dolomite ash;

[0084] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 200 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0085] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0086] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0087] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0088] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1393 mg / kg, and exchangeable magnesium 280 mg / kg.

[0089] Example 9

[0090] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 1000° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 75 g of deionized water to obtain dolomite ash;

[0091] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0092] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0093] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0094] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 3 hours, washing, and drying to obtain a soil conditioner;

[0095] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1403 mg / kg, and exchangeable magnesium 278 mg / kg.

[0096] Example 10

[0097] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 1000° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 75 g of deionized water to obtain dolomite ash;

[0098] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0099] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0100] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0101] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 6 hours, washing, and drying to obtain a soil conditioner;

[0102] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1417 g / kg, and exchangeable magnesium 292 mg / kg.

[0103] Embodiment 11

[0104] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 1000° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 75 g of deionized water to obtain dolomite ash;

[0105] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0106] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0107] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0108] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 12 hours, washing, and drying to obtain a soil conditioner;

[0109] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.55, exchangeable calcium 1513 g / kg, and exchangeable magnesium 304 mg / kg.

[0110] Example 12

[0111] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 1000° C. at a heating rate of 5° C. / min and calcined for 4 h to obtain calcined dolomite. The calcined dolomite was then dissolved in 75 g of deionized water to obtain dolomite ash;

[0112] (2) adding 20 g of natural dolomite to 36.27 ml of a 37% hydrochloric acid solution, stirring for 1 h, filtering, then adding the dolomite emulsion obtained in step (1), adjusting the pH to neutral, filtering, obtaining a mixed solution, and then adding 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0113] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water, stir and disperse evenly to obtain a 1 wt% sodium alginate solution;

[0114] (4) Weighing 3 g of natural dolomite and 3 g of bentonite, and adding them in sequence to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0115] (5) using a YZ15-13A peristaltic pump, the silicone hose of the peristaltic pump is 16#, and the speed is set to 15.0 rpm; pumping the mixed slurry obtained in step (4) into the acidified dolomite cross-linking agent, soaking for 24 hours, washing, and drying to obtain a soil conditioner;

[0116] (6) 5 g of soil conditioner was placed in 500 g of acidic red soil for an indoor simulation experiment. Samples were taken after 2 months and the soil pH was measured to be 6.60, exchangeable calcium 1468 g / kg, and exchangeable magnesium 294 mg / kg.

Claims

1. A conditioner for improving acidic soil, characterized in that: Prepared as follows: (1) grinding and sieving natural dolomite, placing it in a muffle furnace, heating it to 800-1000° C. and maintaining it for 3-5 hours to obtain calcined dolomite; dissolving the obtained calcined dolomite in deionized water to obtain dolomite ash emulsion; (2) adding natural dolomite to a hydrochloric acid solution, stirring, filtering, adding the dolomite emulsion obtained in step (1) to the filtrate to adjust the pH to neutral, filtering, and diluting the filtrate with deionized water to obtain an acidified dolomite cross-linking agent; (3) mixing sodium alginate and deionized water, stirring and dispersing them uniformly to obtain a sodium alginate solution; (4) adding natural dolomite and bentonite to the sodium alginate solution obtained in step (3) in sequence and mixing them to obtain a mixed slurry; (5) The mixed slurry obtained in step (4) is pumped into the acidified dolomite cross-linking agent obtained in step (2) by a peristaltic pump, and the mixture is soaked, molded, washed, and dried to obtain the conditioner for improving acidic soil.

2. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (1), the heating rate during calcination is 5°C / min.

3. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (1), the mass ratio of calcined dolomite to deionized water is 2.5:12.5-75.

4. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (2), the mass fraction of the hydrochloric acid solution is 37%; the molar ratio of natural dolomite to hydrochloric acid is 1:

4.

5. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (2), the feed ratio of natural dolomite to deionized water is 20:50-200, g / mL.

6. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (3), the mass fraction of the sodium alginate solution is 1%.

7. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (4), the mass ratio of natural dolomite to bentonite is 0-4:2-6.

8. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (4), the mass ratio of the total mass of natural dolomite and bentonite to the mass ratio of sodium alginate is 6:

1.

9. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (5), the volume ratio of the mixed slurry to the acidified dolomite cross-linking agent is 100:50-200.

10. The conditioner for improving acidic soil according to claim 1, characterized in that: In step (5), the soaking and molding time is 3 to 24 hours.

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