Matrix soil based on titanium gypsum as raw material as well as preparation method and application of matrix soil

Abstract

The invention relates to the technical field of titanium gypsum treatment, in particular to matrix soil based on titanium gypsum as a raw material as well as a preparation method and application of the matrix soil, and the matrix soil comprises the following components: treated titanium gypsum and an organic fertilizer in a mass ratio of (30-40): 1. According to the method, after titanium gypsum is smashed, washed with citric acid and washed with high-pressure water, most iron in the titanium gypsum is removed, the titanium gypsum is mixed with organic fertilizer to form matrix soil, the matrix soil is directly used as planting soil to be applied to agricultural production, under the mutual synergistic effect, the irrigation water consumption in the crop planting process can be reduced, and the crop yield is increased. And moreover, the large-scale application of the titanium gypsum is realized, the application range of the titanium gypsum is expanded, and the use value of the titanium gypsum is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium gypsum treatment, and particularly relates to a matrix soil based on titanium gypsum as raw material and a preparation method and application thereof. BACKGROUND

[0002] Titanium dioxide is the third largest inorganic salt product in the world, and is widely used in the fields of paint, plastic, ink and the like. China is a large country of titanium dioxide production. Since starting late, the main production process is still the sulfuric acid process. In the production process of titanium dioxide by the sulfuric acid process, a large amount of acidic wastewater containing sulfuric acid is generated, and needs to be neutralized by adding limestone, lime, carbide slag and the like. The generated gypsum is dewatered by pressure filtration to obtain a by-product titanium gypsum. The titanium gypsum has a high impurity content, especially 15% of iron. At present, the global titanium gypsum reserves are large, and open-air stacking is easy to cause dust pollution, so the application of the titanium gypsum is limited. The titanium gypsum is used for cement retarder or gypsum board raw material, but the added value is low. The titanium gypsum is also used for preparing a soil conditioner, but the titanium gypsum is not effectively treated, and the improvement effect is not outstanding. The titanium gypsum has fine texture, and has good water retention. The titanium gypsum can provide calcium elements and sulfur elements necessary for plant growth. Therefore, the titanium gypsum is reasonably used in agricultural planting after treatment, which is the most valuable use direction. SUMMARY

[0003] In view of the above technical problems, the present application provides a method capable of using titanium gypsum to prepare matrix soil and applying the matrix soil to agricultural planting.

[0004] To solve the above technical problems, the matrix soil based on titanium gypsum as raw material provided by the present application comprises the following components: treated titanium gypsum, and organic fertilizer with a mass ratio of 30-40:1.

[0005] Further, the organic fertilizer is selected from one of poultry manure fermented organic fertilizer and earthworm fermented organic fertilizer, the total nutrient (N-P2O5-K2O) of the organic fertilizer is greater than or equal to 5%, and the organic matter content is greater than or equal to 45%.

[0006] Meanwhile, a preparation method of the matrix soil based on titanium gypsum as raw material is disclosed, comprising the following steps:

[0007] S1, crushing and screening titanium gypsum;

[0008] S2, drying the screened titanium gypsum powder to a water content of less than or equal to 5%;

[0009] S3, preparing a 1% citric acid solution, putting the dried titanium gypsum of S2 into an acid-resistant tank, uniformly spraying the prepared citric acid solution onto the titanium gypsum, and draining after standing and penetrating for a period of time;

[0010] S4, rinse the titanium gypsum after draining 3-4 times, until the iron content in the titanium gypsum is reduced to ≤3%;

[0011] S5, the rinsed titanium gypsum is mixed with organic fertilizer according to the above ratio to form a substrate soil.

[0012] Further, in S1, the titanium gypsum is crushed to a particle size of ≤5mm, and the undersize is taken, and the oversize is re-crushed.

[0013] Further, in S2, the titanium gypsum powder is laid out on a well-ventilated drying site for natural air drying, with a site temperature of 25±3℃ and a humidity of ≤40%.

[0014] Further, in S3, food-grade citric acid with a purity of ≥99% is stirred uniformly with deionized water to prepare a citric acid solution; the citric acid solution is sprayed on the titanium gypsum at a mass ratio of 1:2, and after spraying, it is left to penetrate for 2-3 hours.

[0015] Further, in S4, the water pressure during rinsing is ≥0.3MPa, and the water used for each rinse is 1.5 times the mass of the titanium gypsum.

[0016] Also disclosed is an application of a substrate soil based on titanium gypsum as a raw material in agricultural planting.

[0017] Further, when planting in a substrate tank, the substrate soil is filled into the substrate tank; when planting in a field, the substrate soil is laid out in the field, and the substrate soil is laid out to a thickness of ≥20cm.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1. By crushing the titanium gypsum, washing it with citric acid, and rinsing it with high-pressure water, most of the iron in the titanium gypsum is removed, and it is mixed with organic fertilizer to form a substrate soil, which is directly used as planting soil in agricultural production. Under the synergistic effect, the irrigation water consumption during crop planting can be reduced, the crop yield can be improved, the application of titanium gypsum can be realized, the application range can be expanded, and the use value of titanium gypsum can be improved.

[0020] 2. The substrate soil prepared by the present application can supplement the calcium and sulfur elements required by plants after removing most of the iron in the titanium gypsum through citric acid washing. The effectiveness of calcium is promoted by citric acid, which helps to improve soil structure, enhance soil aeration and water retention, and improve plant growth. Compared with the substrate soil prepared by pickling titanium gypsum with inorganic acids such as sulfuric acid, citric acid treatment avoids the introduction of a large amount of sulfate ions, reduces the risk of soil salt accumulation caused by excessive sulfate, and has the advantages of high germination rate and no seedling burn. DETAILED DESCRIPTION

[0021] The present application will be further described below.

[0022] Embodiment 1

[0023] A matrix soil based on titanium gypsum as raw material, comprising the following components: treated titanium gypsum, organic fertilizer mass ratio 30:1. The organic fertilizer is selected from fermented organic fertilizer of poultry manure, the total nutrient content (N-P2O5-K2O) of the organic fertilizer is ≥5%, and the organic matter content is ≥45%.

[0024] A preparation method of a matrix soil based on titanium gypsum as raw material, comprising the following steps:

[0025] (1) Titanium gypsum crushing: using a jaw crusher with a model of PE-200x300 to crush the titanium gypsum, using a vibrating screen with a mesh size of 5 mm for screening, taking the undersize product with a particle size ≤5 mm, and re-feeding the oversize product into the jaw crusher for crushing;

[0026] (2) Titanium gypsum air-drying and dehydration: spreading the screened titanium gypsum powder on a ventilated drying site with a temperature of 25°C and a humidity of 36%, with a spreading thickness of 8 cm for natural air-drying, at this time, detecting the water content according to the water content detection process in the national standard "GB / T5484-2012 Gypsum Chemical Analysis Method", and the water content is 4.1%;

[0027] (3) Citric acid preparation: taking 10 kg of food-grade citric acid with a purity ≥99%, feeding it into a stirring tank, and at the same time, taking 990 kg of deionized water into the stirring tank for sufficient stirring, to prepare a 1% citric acid solution;

[0028] (4) Acid pickling: placing the naturally air-dried titanium gypsum into an acid-resistant tank, spreading it flat, connecting a spray pipe and a spray head on the acid-resistant tank, and uniformly spraying the prepared citric acid solution onto the titanium gypsum, with a mass ratio of citric acid solution to titanium gypsum of 1:2, and after 2 hours of standing and penetration, draining;

[0029] (5) Washing: using a high-pressure cleaning machine to wash the drained titanium gypsum for 3 times, with a water pressure requirement ≥0.3 MPa, and the water amount for each washing is 1.5 times the mass of the titanium gypsum, in this process, using ICP-MS detection method to detect the iron content in the titanium gypsum, and the iron content in the titanium gypsum is reduced to 2.8%;

[0030] (6) Matrix soil preparation: feeding the washed titanium gypsum and the organic fertilizer into a double-shaft mixer according to the above-mentioned proportion, adjusting the rotating speed to 30 r / min, and stirring and mixing for 20 min to form the matrix soil.

[0031] Application of matrix soil based on titanium gypsum as raw material in agricultural planting. Matrix tank planting is adopted, the prepared matrix soil is divided and packed into 50L matrix tanks, a total of ten tanks are set, and the matrix tanks are placed in a greenhouse, a drainage layer is arranged at the bottom of the matrix tank, 10 corn seeds of "Zhengdan 958" are planted in each tank; the temperature in the greenhouse is controlled at 25-30℃, the light cycle is 12h / day, and the humidity is 50%-60%; after planting, water is poured thoroughly, 20L of water is poured per tank, and then 10L of drip irrigation is carried out every 7 days to maintain the humidity of the matrix soil at 65%±3%.

[0032] After 7 days, 98 seeds germinate in the matrix tank, and the germination rate reaches 98%; after 3 weeks, the seedling height is 35cm, the SPAD value is detected by SPAD-502 chlorophyll instrument, and the SPAD value is 42.3; the total growth cycle of the plant uses water 120L per matrix tank.

[0033] Example 2

[0034] The difference between this example and example 1 is that the mass ratio of treated titanium gypsum to organic fertilizer is 33:1, and the organic fertilizer is selected as earthworm fermented organic fertilizer; the air-drying site temperature of titanium gypsum is 27℃, and the humidity is 32%, the water content after air-drying is detected to be 4.6%; the soaking time during pickling is 3 hours; the iron content in titanium gypsum is reduced to 2.5%; the mixing of titanium gypsum and organic fertilizer is carried out by a double-shaft mixer at a speed of 40r / min for 18 minutes. The rest is the same as example 1.

[0035] Application of matrix soil based on titanium gypsum as raw material in agricultural planting. Matrix tank planting is adopted, the prepared matrix soil is divided and packed into 50L matrix tanks, a total of ten tanks are set, and the matrix tanks are placed in a greenhouse, a drainage layer is arranged at the bottom of the matrix tank, 10 corn seeds of "Zhengdan 958" are planted in each tank; the temperature in the greenhouse is controlled at 25-30℃, the light cycle is 12h / day, and the humidity is 50%-60%; after planting, water is poured thoroughly, 20L of water is poured per tank, and then 10L of drip irrigation is carried out every 7 days to maintain the humidity of the matrix soil at 65%±3%.

[0036] After 7 days, 98 seeds germinate in the matrix tank, and the germination rate reaches 98%; after 3 weeks, the seedling height is 35cm, the SPAD value is detected by SPAD-502 chlorophyll instrument, and the SPAD value is 42.3; the total growth cycle of the plant uses water 120L per matrix tank.

[0037] Example 3

[0038] The difference between this example and example 1 is that the mass ratio of treated titanium gypsum to organic fertilizer is 33:1, and the organic fertilizer is selected as earthworm fermented organic fertilizer; the air-drying site temperature of titanium gypsum is 27℃, and the humidity is 32%, the water content after air-drying is detected to be 4.6%; the soaking time during pickling is 3 hours; the iron content in titanium gypsum is reduced to 2.5%; the mixing of titanium gypsum and organic fertilizer is carried out by a double-shaft mixer at a speed of 40r / min for 18 minutes. The rest is the same as example 1.

[0039] Application of matrix soil based on titanium gypsum in agricultural planting. Field planting is adopted, and a test field in the arid region of northwest China is selected. The initial water content of the test field is 8%, the land is ploughed, and then the prepared matrix soil is laid in the field. The matrix soil is laid to a thickness of 21.4 cm, and "Ningchun No. 4" wheat is strip-seeded with a row spacing of 20 cm and a seeding amount of 150 kg / hm 2 ; irrigation is performed 6 times during the whole growth period, with a total water consumption of 150 m 3 / hm 2 , and the yield of wheat per mu after harvesting is 486 kg.

[0040] Example 4

[0041] The difference between this example and Example 1 is that the mass ratio of the treated titanium gypsum to the organic fertilizer is 40:1, the air-drying site temperature of the titanium gypsum is 28℃, the air-drying site humidity is 39%, the water content of the titanium gypsum after air-drying is detected to be 3.8%, the titanium gypsum is allowed to stand for 2.4 hours for penetration during pickling, the iron content in the titanium gypsum is reduced to 2.7%, and the titanium gypsum and the organic fertilizer are mixed by a double-shaft mixer at a rotating speed of 40 r / min for 20 min. The rest is the same as in Example 1.

[0042] Application of matrix soil based on titanium gypsum in agricultural planting. Field planting is adopted, and a test field in the arid region of northwest China is selected. The initial water content of the test field is 8%, the land is ploughed, and then the prepared matrix soil is laid in the field. The matrix soil is laid to a thickness of 21.4 cm, and "Ningchun No. 4" wheat is strip-seeded with a row spacing of 20 cm and a seeding amount of 150 kg / hm 2 ; irrigation is performed 6 times during the whole growth period, with a total water consumption of 150 m 3 / hm 2 , and the yield of wheat per mu after harvesting is 478 kg.

[0043] Example 5

[0044] The difference between this example and Example 4 is that the mass ratio of the treated titanium gypsum to the organic fertilizer is 40:1, and the rest is the same as in Example 4.

[0045] This example carries out an extreme drought simulation experiment. A greenhouse test field is selected, the prepared matrix soil is laid in the field, the matrix soil is laid to a thickness of 21 cm, and rye grass is planted. The day temperature in the greenhouse is controlled to be 35℃, the night temperature is controlled to be 20℃, and the humidity is controlled to be 30%. Only one irrigation is performed after seeding, and the subsequent water is relied on the water retention of the matrix soil. The soil humidity is still maintained at 45% after 10 days of detection. After 40 days, one harvest of rye grass is obtained, with a fresh weight of 2.8 kg / m 2 .

[0046] Comparative Example 1

[0047] The titanium gypsum is not acid washed with citric acid, and is mixed with organic fertilizer to form a substrate soil in a mass ratio of 30:1, and the other parts are the same as in Example 1. Corn seeds are sowed in the substrate tank, and the same planting and management conditions as in Example 1 are maintained. After 7 days, 64 seeds germinate in the substrate tank, and the germination rate is 64%. The seedlings show yellow leaves, and after 3 weeks, the seedlings have a height of 28 cm, and the SPAD value is 37.5 detected by a SPAD-502 chlorophyll meter. During the management process, the soil is seriously hardened, and water is needed to be poured once every 3 days to maintain the substrate soil humidity. The water used in each substrate tank during the whole growth cycle of the plant is 180 L.

[0048] Comparative Example 2

[0049] The titanium gypsum is acid washed with sulfuric acid, and is mixed with organic fertilizer to form a substrate soil in a mass ratio of 30:1, and the other parts are the same as in Example 1. Corn seeds are sowed in the substrate tank, and the same planting and management conditions as in Example 1 are maintained. After 7 days, 73 seeds germinate in the substrate tank, and the germination rate is 73%. The seedlings show a seedling burn phenomenon, and after 3 weeks, the survival rate of the germinated seedlings is only 57%. During the management process, the soil is salted out. The water used in each substrate tank during the whole growth cycle of the plant is 215 L.

[0050] Comparative Example 3

[0051] A test field in a northwest arid region is selected, the initial water content of the test field is 8%, the land is ploughed and leveled, and the substrate soil is not paved and covered. The “Ningchun 4” wheat is strip sowed with a row spacing of 20 cm and a sowing amount of 150 kg / hm 2 . The wheat is irrigated 8 times during the whole growth period, the total water used is 200 m 3 / hm 2 , and the yield of the wheat after harvest is 432 kg per mu.

[0052] Comparative Example 4

[0053] The titanium gypsum is acid washed with citric acid, and is mixed with organic fertilizer to form a substrate soil in a mass ratio of 50:1, and the other parts are the same as in Example 1. A test field in a northwest arid region is selected, the initial water content of the test field is 8%, the land is ploughed and leveled, and the substrate soil is paved and covered. The “Ningchun 4” wheat is strip sowed with a row spacing of 20 cm and a sowing amount of 150 kg / hm 2 . The wheat is irrigated 6 times during the whole growth period, the total water used is 134 m 3 / hm 2 , and the yield of the wheat after harvest is 454 kg per mu.

[0054] Comparative Example 5

[0055] The embodiment carries out extreme drought simulation test, selects greenhouse test field, does not pave matrix soil, plants rye grass, controls greenhouse daytime temperature 35 DEG C, night temperature 20 DEG C, humidity 30%, only irrigates water once after sowing, and soil humidity is reduced to 25% after 10 days detection;After 40 days, one harvest is obtained, and the fresh weight of rye grass is 2.1 kg / m 2 .

[0056] Matrix soil performance test is carried out in the northwest arid region, and the specific test results are shown in the following table 1.

[0057] Table 1. Comparison table of test data

[0058]

[0059]

[0060] Meanwhile, matrix soil extreme drought simulation test is carried out, and the specific test results are shown in the following table 2.

[0061] Table 2. Comparison table of extreme drought simulation test data

[0062]

[0063] Conclusion:

[0064] 1. After the matrix soil of the application is used for agricultural planting, the irrigation water consumption of crops in the field management process is reduced by more than 25% compared with not using the matrix soil of the application, and the yield per mu of land after crop harvesting is increased by more than 10.65%, therefore, the matrix soil of the application has obvious water retention property, can reduce the irrigation water consumption of crops, and has a significant effect on improving crop yield after use.

[0065] 2. After the main raw material titanium gypsum of the matrix soil is treated by citric acid, the germination rate of crops reaches more than 97% and the SPAD value of crops reaches more than 42.3, compared with not being treated by citric acid and being used directly, the germination rate of crops is increased by more than 33%, and the SPAD value of crops is increased by 12.8%; meanwhile, after the titanium gypsum is prepared into matrix soil by acid washing with sulfuric acid, it is found that the germination rate of seeds is increased compared with the matrix soil prepared by titanium gypsum without acid washing, but during the seedling growth period, the matrix soil after acid washing with sulfuric acid has the phenomenon of seedling burn, and the survival rate of seedlings is only 57%, and the soil will precipitate salt, which affects the survival rate of plants and yield, and the irrigation water consumption is increased.

[0066] 3. After the titanium gypsum cleaned by citric acid and the organic fertilizer of the matrix soil are not prepared and used according to the specific proportion, the water consumption is increased by 11.7% compared with the matrix soil prepared according to the specific proportion, and the crop yield is reduced by more than 5.3% compared with the matrix soil prepared according to the specific proportion.

Claims

1. A matrix soil based on titanium gypsum as raw material, characterized in that: The invention comprises the following components: treated titanium gypsum and organic fertilizer in a mass ratio of 30-40:

1.

2. The matrix soil based on titanium gypsum as raw material according to claim 1, characterized in that: The organic fertilizer is selected from one of poultry and livestock excrement fermented organic fertilizer and earthworm fermented organic fertilizer. The total nutrient content (N-P2O5-K2O) of the organic fertilizer is ≥5%, and the organic matter content is ≥45%.

3. A method for preparing matrix soil based on titanium gypsum as raw material, characterized in that: The steps include: S1, crushing and screening the titanium gypsum; S2. Dry the sieved titanium gypsum powder to a moisture content of ≤5%; S3, prepare a 1% citric acid solution, put the titanium gypsum dried in S2 into an acid-resistant tank, spray the prepared citric acid solution evenly on the titanium gypsum, let it stand for a while and then drain; S4. Rinse the drained titanium gypsum 3-4 times until the iron content in the titanium gypsum is reduced to ≤3%; S5. The washed titanium gypsum and the organic fertilizer are stirred and mixed according to the above proportions to form a matrix soil.

4. The method for preparing matrix soil based on titanium gypsum as raw material according to claim 3, characterized in that: In S1, the titanium gypsum is crushed to a particle size of ≤5 mm, the undersize is taken, and the oversize is crushed again.

5. The method for preparing matrix soil based on titanium gypsum as raw material according to claim 3, characterized in that: In S2, the titanium gypsum powder is spread flat on a ventilated and dry site to dry naturally, with a site temperature of 25±3° C. and a humidity of ≤40%.

6. The method for preparing matrix soil based on titanium gypsum as raw material according to claim 3, characterized in that: In S3, food-grade citric acid with a purity of ≥99% is mixed evenly with deionized water to prepare a lemon water solution; the citric acid solution is sprayed in a mass ratio of 1:2 to titanium gypsum, and the solution is allowed to stand and penetrate for 2-3 hours after spraying.

7. The method for preparing matrix soil based on titanium gypsum as raw material according to claim 3, characterized in that: In S4, the water pressure during flushing is ≥0.3MPa, and the water consumption for each flushing is 1.5 times the mass of titanium gypsum.

8. An application of a matrix soil based on titanium gypsum as a raw material according to any one of claims 1 to 2 in agricultural planting.

9. The use of the matrix soil based on titanium gypsum as raw material according to claim 8, characterized in that: When planting in substrate troughs, fill the substrate soil into the substrate troughs; when planting in the field, spread the substrate soil flat in the field, and the thickness of the substrate soil should be ≥20cm.

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