Soil matrix prepared based on pyrite slag and application thereof

Abstract

The invention discloses a soil matrix prepared on the basis of pyrite slag, a preparation method of the soil matrix comprises the steps that the pyrite slag, hair and sulfuric acid are mixed together for pretreatment, and the weight ratio of the pyrite slag to the hair to the sulfuric acid is (5-10): (0.5-2): (5-10). Hydrolyzed protein obtained through hydrolysis is complexed with heavy metal in the iron sulfide slag, so that the heavy metal in the pyrite slag can be well removed, the content of the heavy metal in the pyrite slag is remarkably reduced, a soil matrix prepared from the pyrite slag is suitable for plant growth, and heavy metal pollution of soil is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of pyrite slag soilification, and in particular to a soil matrix prepared based on pyrite slag and application thereof. Background Art

[0002] Pyrite slag (i.e. pyrite cinder) is an industrial waste discharged from the process of producing sulfuric acid using pyrite or sulfur-containing tailings as raw materials. It is usually produced in the ironmaking process of iron furnaces. Its main components are iron, ferrous oxide and silicon dioxide, and it contains certain metal elements such as calcium, magnesium, lead, manganese and other metal elements. my country is a major producer of sulfuric acid. The sulfuric acid production industry produces about 7×10 6 Pyrite slag accounts for 1 / 3 of the total chemical waste. However, most of the pyrite slag is currently treated by landfill, which not only occupies a large amount of land and reduces arable land, but also due to weathering and rain, harmful components in pyrite slag enter the atmosphere, soil, and water bodies, seriously polluting the environment and causing great pollution to the environment (such as the large amount of acidic wastewater produced will leach heavy metal ions such as Cd2+, As3+, Pb2+, Cu2+, and Zn2+). Although pyrite slag has lost its mineral processing value, it contains various elements required for plant growth and high concentrations of iron. Therefore, how to effectively utilize the high nutritional elements in it, while eliminating the hazards of other elements, apply it to plant growth, increase my country's agricultural land, and at the same time turn waste into treasure, save energy, reduce carbon emissions, reduce mining, and reduce land ecological damage. To achieve ecological environment construction, ecological environment governance, ecological environment restoration, green and sustainable development. At present, most of the existing technologies disclosed for improving planting soil are aimed at planting green plants or trees for landscaping. However, because their raw materials are directly utilized from waste tailings or slag, etc., which contain a large amount of heavy metals or harmful components, they are not suitable for planting crops, that is, they cannot meet the soil requirements for planting crops. Summary of the invention

[0003] One object of the present invention is to solve the above-mentioned problem and provide a soil matrix prepared based on pyrite slag, which is not only suitable for planting green plants or trees for landscaping, but also suitable for planting crops. The soil matrix of the present invention has a low heavy metal content, reduces soil pollution, and is suitable for planting crops.

[0004] To achieve the above purpose, the technical solution provided by the present invention is:

[0005] In a first aspect of the present invention, a soil matrix prepared based on pyrite slag is provided, wherein the preparation method of the soil matrix comprises: mixing pyrite slag, hair, and sulfuric acid together for pretreatment, wherein the weight ratio of the pyrite slag, hair, and sulfuric acid is 5-10:0.5-2:5-10. During the process of acid leaching of the pyrite slag to extract iron, the hair is added, and the hair is hydrolyzed under the action of sulfuric acid.

[0006] Preferably, the sulfuric acid concentration is 10-50wt%.

[0007] Preferably, the weight ratio of the pyrite slag, hair and sulfuric acid is 7.5:1:8.

[0008] Preferably, the hair is one or more of chicken feathers, duck feathers and goose feathers.

[0009] Preferably, the pretreatment specifically comprises the following steps: firstly, pyrite slag, hair and sulfuric acid are mixed and then continuously stirred, heated to 85-95° C., reacted for 1-5 hours, and then filtered to obtain filter residue.

[0010] Preferably, the soil matrix prepared based on pyrite slag also includes the following materials: Pichia kudriavzevii and clay.

[0011] Preferably, the specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps:

[0012] Step 1: Mix pyrite slag, hair and sulfuric acid, stir continuously, heat to 85-95°C, react for 1-5 hours, and filter to obtain filter residue;

[0013] Step 2: adding water, Pichia kudriavzevii, sucrose and starch to the filter residue obtained in step 1 and fermenting the mixture for 1-2 days to obtain a fermentation mixture A;

[0014] Step 3: Mix the fermentation mixture A with clay and coconut bran to obtain the soil matrix.

[0015] Preferably, the weight ratio of the filter residue, water, Pichia kudriavzevii, sucrose and starch is 10-20:5-10:0.2-0.5:2-5:2-5; the weight ratio of the fermentation mixture A, clay and coconut bran is 10-20:1-2:1-2.

[0016] Preferably, the concentration of Pichia kudriavzevii is 2×10 7 -2×10 8 CFU / mL.

[0017] In another aspect, the present invention also provides a soil matrix prepared based on pyrite slag for use in planting green plants or crops. The present invention can also be nutrient soil.

[0018] The beneficial effects of the present invention are as follows:

[0019] (1) The present invention adds hair to the process of extracting iron from pyrite slag by acid leaching, and hydrolyzes the hair to obtain hydrolyzed protein, which can be complexed with heavy metals in the pyrite slag to effectively remove heavy metals in the pyrite slag, significantly reduce the heavy metal content in the pyrite slag, make the soil matrix prepared from the pyrite slag suitable for plant growth, and reduce heavy metal pollution in the soil.

[0020] (2) The present invention also utilizes a fermentation method of adding Pichia kudriazewi to increase the pH value of the pyrite slag after acid leaching to make it neutral, and uses a biological method to make the prepared soil matrix neutral and suitable for planting. The acid-base neutralization method is not used, which can reduce the salinization of the prepared soil matrix. DETAILED DESCRIPTION

[0021] The substrate glass, cesium hydroxide, potassium hydroxide and other materials used in the present invention are all purchased from the market.

[0022] In one embodiment of the present invention, the present invention provides a soil matrix prepared based on pyrite slag. In the first aspect of the present invention, a soil matrix prepared based on pyrite slag is provided. The preparation method of the soil matrix comprises: mixing pyrite slag, hair, and sulfuric acid together for pretreatment, wherein the weight ratio of the pyrite slag, hair, and sulfuric acid is 5-10:0.5-2:5-10. Hair is added during the process of acid leaching to extract iron from pyrite slag. The hair is hydrolyzed under the action of sulfuric acid to obtain hydrolyzed protein, which is complexed with the total metals in the pyrite slag to form a complex, which effectively removes heavy metals. The iron element is extracted and hydrolyzed protein is formed to remove heavy metals at the same time. The processing steps are reduced and sulfuric acid is effectively utilized, which saves processing costs and achieves the effect of treating waste with waste. The hair mentioned in the present invention is animal hair, which can be hydrolyzed by acid and alkali hydrolysis to obtain hydrolyzed protein. The sulfuric acid is sulfuric acid that can be purchased on the market.

[0023] In some preferred embodiments, the concentration of sulfuric acid used in the present invention is 10-50 wt %, which is more conducive to hair hydrolysis and can accelerate the hydrolysis rate of keratin.

[0024] In some preferred embodiments, the weight ratio of the pyrite slag, hair, and sulfuric acid is 7.5:1:8.

[0025] In some preferred embodiments, the hair is one or more of chicken feathers, duck feathers, and goose feathers. The keratin content of poultry hair is high and easily hydrolyzed, so the present invention uses one or more of chicken feathers, duck feathers, and goose feathers.

[0026] In some preferred embodiments, the pretreatment specifically includes the following steps: first, pyrite slag, hair, and sulfuric acid are mixed and continuously stirred, heated to 85-95°C, reacted for 1-5 hours, filtered to obtain filter residue, and the filtrate is used to extract metal elements such as iron.

[0027] In some preferred embodiments, the soil matrix prepared based on pyrite slag includes the following materials: Pichia kudriazevii and clay. Pichia kudriazevii is available on the market and is inoculated into the filter residue by culture. The purpose of adding clay in the present invention is to increase the water retention of the soil matrix, because pyrite slag is relatively loose and not easy to retain water, and the nutrients of the prepared soil matrix are easy to be lost. Therefore, the present invention adds clay and absorbs the residual heavy metals that cannot be completely removed, so that the heavy metals cannot migrate to the root system of the crops when planting crops, so that the soil matrix is ​​suitable for planting crops without residual heavy metal elements.

[0028] In some preferred embodiments, the specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps:

[0029] Step 1: Mix pyrite slag, hair and sulfuric acid, stir continuously, heat to 85-95°C, react for 1-5 hours, and filter to obtain filter residue;

[0030] Step 2: adding water, Pichia kudriavzevii, sucrose and starch to the filter residue obtained in step 1 and fermenting the mixture for 1-2 days to obtain a fermentation mixture A;

[0031] Step 3: Mix the fermentation mixture A with clay and coconut bran to obtain the soil matrix.

[0032] In some preferred embodiments, the weight ratio of the filter residue, water, Pichia kudriavzevii, sucrose and starch is 10-20:5-10:0.2-0.5:2-5:2-5; the weight ratio of the fermentation mixture A, clay and coconut bran is 10-20:1-2:1-2.

[0033] In some preferred embodiments, the concentration of Pichia kudriavzevii is 2×10 7 -2×10 8 CFU / mL.

[0034] In another embodiment, the soil matrix obtained as above is used to plant green plants or crops. It can be used in saline-alkali land to optimize the soil structure. The soil matrix of the present invention is mixed with the soil of the saline-alkali land, preferably in a 1:1 ratio, or the present invention is directly spread on the soil surface with a thickness greater than 10 cm for planting, or the present invention is used for potted planting, or the present invention is used for planting in urban green belts.

[0035] Unless otherwise defined herein, the scientific and technical terms used herein have the same meanings as those understood and commonly used by those skilled in the art.

[0036] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any particular theory or mechanism. In this article, all features defined in the form of numerical ranges or percentage ranges, such as quantity, value, concentration and content, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have covered and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0037] The above features mentioned in the present invention or the features mentioned in the embodiments can be combined in any way. All features disclosed in this specification can be used in combination with any combination form, and as long as there is no contradiction in the combination of these features, all possible combinations should be considered to be within the scope of this specification. Each feature disclosed in the specification can be replaced by any alternative feature that can provide the same, equal or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equal or similar features.

[0038] The present invention is further described below in conjunction with specific examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually performed under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, all percentages, ratios, proportions, or parts are by weight. The units mentioned in the weight percentages in the present invention are well known to those skilled in the art. Unless otherwise defined, all professional and scientific terms used in the text have the same meanings as those familiar to those skilled in the art. In addition, any method and material similar or equivalent to the recorded content can be applied to the method of the present invention. The preferred implementation methods and materials described in the text are for demonstration purposes only.

[0039] The pyrite slag used in the embodiment is the slag produced by the sulfuric acid plant.

[0040] Example 1

[0041] The specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps:

[0042] Step 1: Mix 50 kg of pyrite slag, 5 kg of chicken feathers and 50 kg of sulfuric acid, stir continuously, heat to 85°C, react for 1 hour, and filter to obtain a residue;

[0043] Step 2: Add water, Pichia kudriavzevii, sucrose and starch to the residue obtained in step 1 and mix and ferment for 1 day to obtain a fermentation mixture A, wherein the weight ratio of the residue, water, Pichia kudriavzevii, sucrose and starch is 10:5:0.2:2:2, and the concentration of Pichia kudriavzevii is 2×10 7 CFU / mL;

[0044] Step 3: Mix the fermentation mixture A with clay and coconut bran in a weight ratio of 10:1:1 to obtain the soil matrix.

[0045] Example 2

[0046] The specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps:

[0047] Step 1: Mix 100 kg of pyrite slag, 20 kg of chicken feathers and 100 kg of sulfuric acid, stir continuously, heat to 95°C, react for 5 hours, and filter to obtain a residue;

[0048] Step 2: Add water, Pichia kudriavzevii, sucrose and starch to the residue obtained in step 1 and mix and ferment for 2 days to obtain a fermentation mixture A, wherein the weight ratio of the residue, water, Pichia kudriavzevii, sucrose and starch is 20:10:0.5:5:5, and the concentration of Pichia kudriavzevii is 2×10 8 CFU / mL;

[0049] Step 3: Mix the fermentation mixture A with clay and coconut bran in a weight ratio of 20:2:2 to obtain the soil matrix.

[0050] Example 3

[0051] The specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps:

[0052] Step 1: 75 kg of pyrite slag, 10 kg of chicken feathers, and 80 kg of sulfuric acid were mixed in a weight ratio of 7.5:1:8, stirred continuously, heated to 90°C, reacted for 4 hours, and filtered to obtain a residue;

[0053] Step 2: Add water, Pichia kudriavzevii, sucrose and starch to the filter residue obtained in step 1 and mix and ferment for 2 days to obtain a fermentation mixture A, wherein the weight ratio of the filter residue, water, Pichia kudriavzevii, sucrose and starch is 15:7:0.3:3:4, and the concentration of Pichia kudriavzevii is 8×10 7 ;

[0054] Step 3: Mix the fermentation mixture A with clay and coconut bran in a weight ratio of 15:1.3:1.3 to obtain the soil matrix.

[0055] Comparative Example 1

[0056] In step 1 of Example 3, 10 kg of chicken feathers are not added, and the remaining steps are the same as those of Example 3.

[0057] Comparative Example 2

[0058] In step 2 of Example 3, Pichia kudriavzevii was not added, and the remaining steps were the same as those of Example 3.

[0059] Comparative Example 3

[0060] In step 3 of Example 3, no clay is added, and the remaining steps are the same as those of Example 3.

[0061] The soil matrix prepared in Examples 1-3 and Comparative Examples 1-3 and the untreated pyrite slag were used as samples to test the heavy metal elements cadmium, lead, arsenic, and pH value in the soil. "Soil Environmental Quality Standard" (GB 15618-2018)

[0062] The test results are shown in Table 1:

[0063] Cadmium mg / kg Lead mg / kg Arsenic mg / kg pH Pyrite slag 1.5 130 30 2.7 Example 1 0.03 10 5 7.1 Example 2 0.02 12 8 7.0 Example 3 0.03 9 4 7.2 Comparative Example 1 1.45 126 29 7.2 Comparative Example 2 0.04 15 9 5.7 Comparative Example 3 0.03 12 7 7.1

[0064] It can be seen from the test results of Examples 1-3 and Comparative Examples 1-3 in the above table that the present invention can effectively remove heavy metal elements in pyrite slag, making the pyrite slag suitable for planting green plants or crops, and significantly reducing heavy metal pollution and acidification of the soil by pyrite slag.

[0065] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A soil matrix prepared based on pyrite slag, characterized in that: The method for preparing the soil matrix comprises: mixing pyrite slag, hair and sulfuric acid together for pretreatment, wherein the weight ratio of the pyrite slag, hair and sulfuric acid is 5-10:0.5-2:5-10.

2. The soil matrix prepared based on pyrite slag according to claim 1, characterized in that: The concentration of sulfuric acid is 10-50wt%.

3. The soil matrix prepared based on pyrite slag according to claim 1, characterized in that: The weight ratio of the pyrite slag, hair and sulfuric acid is 7.5:1:

8.

4. The soil matrix prepared based on pyrite slag according to claim 1, characterized in that: The hair is one or more of chicken feathers, duck feathers and goose feathers.

5. The soil matrix prepared based on pyrite slag according to claim 1, characterized in that: The pretreatment specifically includes the following steps: firstly, pyrite slag, hair and sulfuric acid are mixed and stirred continuously, heated to 85-95° C., reacted for 1-5 hours, and then filtered to obtain filter residue.

6. The soil matrix prepared based on pyrite slag according to claim 1, characterized in that: The soil matrix prepared based on pyrite slag also includes the following materials: Pichia kudriavzevii, clay.

7. A soil matrix prepared based on pyrite slag as claimed in claim 6, characterized in that: The specific preparation method of the soil matrix prepared based on pyrite slag comprises the following steps: Step 1: Mix pyrite slag, hair and sulfuric acid, stir continuously, heat to 85-95°C, react for 1-5 hours, and filter to obtain filter residue; Step 2, adding water, Pichia kudriavzevii, sucrose and starch to the filter residue obtained in step 1, and fermenting the mixture for 1-2 days to obtain a fermentation mixture A; Step 3: Mix the fermentation mixture A with clay and coconut bran to obtain the soil matrix.

8. The soil matrix prepared based on pyrite slag according to claim 7, characterized in that: The weight ratio of the filter residue, water, Pichia kudriavzevii, sucrose and starch is 10-20:5-10:0.2-0.5:2-5:2-5; the weight ratio of the fermentation mixture A, clay and coconut bran is 10-20:1-2:1-2.

9. The soil matrix prepared based on pyrite slag according to claim 6, characterized in that: The concentration of Pichia kudriavzevii was 2×10 7 -2×10 8 CFU / mL.

10. A soil matrix prepared based on pyrite slag as claimed in any one of claims 1 to 9, which is used for planting green plants or crops.