Steel slag fine powder planting sand and preparation method and application thereof

Abstract

The invention relates to the technical field of soilless culture planting sand, in particular to steel slag fine powder planting sand and a preparation method and application thereof. According to the steel slag fine powder planting sand, the steel slag fine powder serves as the main raw material, steelmaking by-products are effectively utilized, environmental pollution is reduced, and the raw material cost is reduced. By adding the pore-forming agent and the glass powder, a uniform porous structure is formed, high air permeability and water and fertilizer retention capacity are achieved, and the strict requirement of orchid root systems for air permeability is met; in addition, ground phosphate rock and potassium chloride are further included, phosphorus and potassium elements necessary for plants are provided, nutrient solution dependence in the initial stage is reduced, and plant growth is promoted; the provided planting sand is more suitable for planting orchid plants with high requirements on air permeability of root systems, and is beneficial to wide application.

Description

Technical Field

[0001] The present application belongs to the technical field of soilless cultivation planting sand, and in particular relates to a kind of steel slag fine powder planting sand and its preparation method and application. Background Art

[0002] Steel slag fines are a byproduct of the steelmaking process. They are primarily composed of oxides and salts formed by the oxidation of impurities such as silicon, manganese, phosphorus, and sulfur. They contain metallic iron (2%-8%), calcium oxide (40%-60%), and magnesium oxide (3%-10%). Its mineral composition is primarily tricalcium silicate, with some dicalcium silicate, dicalcium ferrite, and free calcium oxide. However, the efficient utilization of steel slag fines has long faced challenges: Traditional recycling options include recycling as a smelting solvent, as a raw material for road and construction materials, or as an agricultural fertilizer, but all have significant drawbacks. For example, recycling costs are high and utilization rates are low; road construction materials require large-particle steel slag, making fines difficult to absorb; and agricultural use is limited by the risk of excessive heavy metal content. Furthermore, the production of ceramsite from steel slag requires high-temperature firing (1200°C), which is costly and has poor water retention, making it suitable only for the construction industry and difficult to meet agricultural needs.

[0003] Existing soilless cultivation substrates, such as vermiculite, perlite, and peat, suffer from common performance shortcomings: vermiculite is brittle, perlite is too light and dusty, and peat is limited by its origin and has inconsistent quality. Furthermore, porous planting sand prepared from natural sand (e.g., patent 201210127243.2) suffers from smooth particles, poor adhesion, low water and fertilizer retention, and fixed elements, making it unable to meet the individual needs of plants.

[0004] Therefore, there is an urgent need to provide a sandy soil with a porous structure, good air permeability, and certain water and fertilizer retention functions for use in growing orchids. Summary of the Invention

[0005] The purpose of this application is to provide a steel slag fine powder planting sand and its preparation method and application, aiming to solve the problem that the sandy soil used in soilless cultivation in the existing technology does not have good air permeability and water and fertilizer retention functions.

[0006] To achieve the above application objectives, the technical solutions adopted in this application are as follows:

[0007] In a first aspect, the present application provides a steel slag fine powder seeding sand, comprising the following components in parts by weight:

[0008] 100 parts of steel slag fine powder,

[0009] 5-20 parts of glass powder,

[0010] Plasticizer 0-10 parts,

[0011] 0.5-2 parts of water reducing agent,

[0012] 15-30 parts water,

[0013] 5-30 parts of pore-forming agent,

[0014] 5-10 parts of phosphate rock powder,

[0015] 5-10 parts of potassium chloride.

[0016] In some embodiments, the particle size of the steel slag fine powder is 50-100 μm.

[0017] In some embodiments, the glass powder has a particle size of 10 to 20 μm.

[0018] In some embodiments, the particle size of the phosphate rock and potassium chloride is 50-100 μm.

[0019] In some embodiments, the plasticizer is selected from one or more of calcined kaolin, bentonite, white clay, and ball clay.

[0020] In some embodiments, the water reducer is selected from one or more of lignin sulfonate water reducers, naphthalene water reducers, and melamine water reducers.

[0021] In some embodiments, the pore-forming agent is selected from one or more of graphite, carbon powder, starch, and organic fiber.

[0022] In some embodiments, the steel slag fine powder seeding sand has a porous structure, a particle size of 0.1 to 2 mm, and a bulk density of 1100 to 1200 kg / m 3 , the water retention rate is 61% to 65%.

[0023] In a second aspect, the present application provides a method for preparing steel slag fine powder seeding sand, comprising the following steps:

[0024] Weigh steel slag powder, glass powder, plasticizer, phosphate rock powder, potassium chloride, pore former and water reducer according to the formula and mix them evenly;

[0025] The mixture is poured into a granulator, and a prescribed amount of water is added, and granulation is performed at a speed of 1500-3500 r / min; the granulated particles are dried and sintered, and then cooled to obtain steel slag fine powder seeding sand.

[0026] In some embodiments, the drying temperature is 50-120° C. and the drying time is 30 minutes.

[0027] In some embodiments, the sintering process includes: heating from room temperature to 600-620° C. at 20-40° C. / min, then heating to 700-900° C. at 10-30° C. / min, and keeping the temperature for 10-30 minutes.

[0028] In some embodiments, the particles formed by the granulation are spherical or irregularly rhombic, and the particle size distribution is controlled to be 0.5-2 mm by adjusting the amount of water added.

[0029] In a third aspect, the present application provides an application of steel slag fine powder planting sand, which is used for soilless cultivation of orchid plants, including Dendrobium officinale and Phalaenopsis.

[0030] In some embodiments, the planting sand needs to be regularly supplemented with fertilizer or nutrient solution during use to maintain the nutrients required for plant growth; and the planting sand can be reused multiple times, and the overall cost is lower than that of peat substrate.

[0031] The steel slag fine powder planting sand provided in the first aspect of this application uses steel slag fine powder as the main raw material, effectively utilizes steelmaking by-products, reduces environmental pollution, and reduces raw material costs. By adding pore-forming agents and glass powder, a uniform porous structure is formed, which has both high air permeability and water and fertilizer retention capabilities, meeting the strict air permeability requirements of the roots of orchid plants; in addition, it also includes phosphate rock powder and potassium chloride to provide the phosphorus and potassium elements necessary for plants, reduce initial nutrient solution dependence, and promote plant growth; the provided planting sand is more suitable for planting orchid plants with high root permeability requirements. As a soilless cultivation substrate to replace peat, its advantages of large pores and not easy to pulverize are more obvious, and the planting effect is better; and, because the steel slag fine powder planting sand has good hardness and can be reused many times, the comprehensive cost of the steel slag fine powder planting sand is lower than most soilless planting substrates such as peat, which is conducive to wide application.

[0032] The second aspect of the present application provides a method for preparing steel slag fine powder planting sand, which realizes large-scale production through a four-step process of mixing, granulation, drying, and sintering, and low-temperature sintering reduces energy consumption costs, ensuring a simple and efficient process; in this preparation method, there are no complicated processing steps throughout the entire process, and the beneficial components in the steel slag fine powder are fully retained, ensuring maximum resource utilization and improving the nutritional value of the matrix. This preparation method is conducive to industrial application.

[0033] The application of the steel slag fine powder planting sand provided in the third aspect of this application, due to the high air permeability and moderate water retention of the provided planting sand, can perfectly match the root requirements of orchid plants such as Dendrobium officinale and Phalaenopsis, and significantly improve the survival rate and growth rate; at the same time, it can replace traditional substrates such as peat and vermiculite, solve their problems of easy pulverization and uneven quality, and is conducive to soilless cultivation and promotes the development of green agriculture. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0035] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0036] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0037] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0039] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0040] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. For example, a first XX could also be referred to as a second XX, and similarly, a second XX could also be referred to as a first XX, without departing from the scope of the embodiments of this application. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0041] In a first aspect, an embodiment of the present application provides a steel slag fine powder seeding sand, comprising the following components in parts by weight:

[0042] 100 parts of steel slag fine powder,

[0043] 5-20 parts of glass powder,

[0044] Plasticizer 0-10 parts,

[0045] 0.5-2 parts of water reducing agent,

[0046] 15-30 parts water,

[0047] 5-30 parts of pore-forming agent,

[0048] 5-10 parts of phosphate rock powder,

[0049] 5-10 parts of potassium chloride.

[0050] The steel slag fine powder planting sand provided in the first aspect of the embodiment of the present application uses steel slag fine powder as the main raw material, effectively utilizes steelmaking by-products, reduces environmental pollution, and reduces raw material costs. By adding pore-forming agents and glass powder, a uniform porous structure is formed, which has both high air permeability and water and fertilizer retention capabilities, meeting the strict air permeability requirements of the roots of orchid plants; in addition, it also includes phosphate rock powder and potassium chloride to provide the phosphorus and potassium elements necessary for plants, reduce initial nutrient solution dependence, and promote plant growth; the provided planting sand is more suitable for planting orchid plants with high requirements for air permeability of the root system, and as a soilless cultivation substrate to replace peat, its advantages of large pores and non-pulverization are more obvious, and the planting effect is better; and, because the steel slag fine powder planting sand has good hardness and can be reused many times, the comprehensive cost of the steel slag fine powder planting sand is lower than that of most soilless planting substrates such as peat, which is conducive to wide application.

[0051] In some embodiments, 100 parts by weight of fine steel slag powder is used as the substrate, wherein the fine steel slag powder is steel mill waste. In some embodiments, the fine steel slag powder has a particle size of 50 to 100 μm. Using fine steel slag powder as a raw material to prepare planting sand provides an efficient way to utilize solid waste while reducing the cost of agricultural planting substrate raw materials.

[0052] In some embodiments, 100 parts by weight of fine steel slag powder is used as the base material, and 5-20 parts of glass powder are also included. In some embodiments, the glass powder has a particle size of 10-20 μm. The glass powder is required to have a particle size of less than 20 μm and is extremely fine. This allows it to bond coarser steel slag powder together at high temperatures without destroying its own pore structure.

[0053] In some embodiments, the base material is 100 parts by weight of fine steel slag powder, and further comprises 0-10 parts of a plasticizer. In some embodiments, the plasticizer is selected from one or more of calcined kaolin, bentonite, white clay, and ball clay.

[0054] In some embodiments, the base material comprises 0.5-2 parts of a water reducer, based on 100 parts by weight of fine steel slag powder. In some embodiments, the water reducer is selected from one or more of lignin sulfonate water reducers, naphthalene-based water reducers, and melamine-based water reducers. Providing a water reducer can reduce water consumption, improve particle density, and prevent cracking due to excessive drying.

[0055] In some embodiments, 100 parts by weight of fine steel slag powder is used as the base material, and further includes: 15-30 parts by weight of water.

[0056] In some embodiments, the base material comprises 5-30 parts by weight of a pore-forming agent, based on 100 parts by weight of fine steel slag powder. The pore-forming agent decomposes during sintering to form uniform pores, allowing for precise control of the balance between air permeability and water retention. In some embodiments, the pore-forming agent is selected from one or more of graphite, carbon powder, starch, and organic fibers.

[0057] In some embodiments, 100 parts by weight of fine steel slag powder is used as the base material, and further comprises: 5-10 parts of phosphate rock powder. In some embodiments, the phosphate rock powder has a particle size of 50-100 μm.

[0058] In some embodiments, 100 parts by weight of fine steel slag powder is used as the base material, and further comprises: 5-10 parts of potassium chloride. In some embodiments, the particle size of the potassium chloride is 50-100 μm.

[0059] In some embodiments, the steel slag fine powder seeding sand has a porous structure, a particle size of 0.1 to 2 mm, and a bulk density of 1100 to 1200 kg / m 3 The water retention rate is 61% to 65%. The particle size is controlled within the range of 0.1-2mm to avoid dust pollution and provide enough space for root expansion; the bulk density is limited to 1100-1200kg / m 3 Ensures substrate stability, superior to lightweight perlite. Limited to a water retention rate of 61%-65%, it ensures that the planting sand has both water retention and air permeability, superior to traditional sand substrates and peat.

[0060] A second aspect of the present invention provides a method for preparing steel slag fine powder seeding sand, comprising the following steps:

[0061] S01. Weigh steel slag powder, glass powder, plasticizer, phosphate rock, potassium chloride, pore-forming agent and water-reducing agent according to the formula and mix well;

[0062] S02. Pour the mixture into a granulator, add the formulated amount of water, and granulate at a speed of 1500-3500 r / min; dry and sinter the granulated particles, and obtain fine steel slag powder seeding sand after cooling.

[0063] The second aspect of the embodiment of the present application provides a method for preparing steel slag fine powder planting sand, which realizes large-scale production through a four-step process of mixing, granulation, drying, and sintering, and low-temperature sintering reduces energy consumption costs, ensuring a simple and efficient process; in this preparation method, there are no complicated processing steps throughout the entire process, and the beneficial components in the steel slag fine powder are fully retained, ensuring maximum resource utilization and improving the nutritional value of the matrix. This preparation method is conducive to industrial application.

[0064] In step S01, fine steel slag powder, glass powder, plasticizer, phosphate rock powder, potassium chloride, pore former, and water reducer are weighed according to the recipe and mixed evenly. The addition amount of each component and the selection of each type are discussed above and will not be repeated here to save space.

[0065] In step S02, the mixture is poured into a granulator, a prescribed amount of water is added, and granulation is performed at a rotation speed of 1500-3500 r / min; the granulated particles are dried and sintered, and then cooled to obtain steel slag fine powder seeding sand.

[0066] In some embodiments, the drying temperature is 50-120° C. and the drying time is 30 minutes. Drying at a low temperature of 50-120° C. prevents cracking of the particles and fully removes moisture, thereby providing a stable foundation for subsequent sintering.

[0067] In some embodiments, the sintering process includes heating from room temperature to 600-620°C at a rate of 20-40°C / min, then heating to 700-900°C at a rate of 10-30°C / min, and holding for 10-30 minutes. The staged heating (20-40°C / min to 600°C, then 10-30°C / min to 700-900°C) can avoid thermal stress-induced particle fracture and ensure the uniformity of the porous structure. Holding for 10-30 minutes allows the glass powder to fully melt and bond, enhancing particle strength (cylinder crushing rate 20%-23%) while retaining porosity.

[0068] In some embodiments, the particles formed by the granulation are spherical or irregularly diamond-shaped. The spherical or irregularly diamond-shaped particles (0.5-2 mm) increase the contact area between particles, improve the stability of the matrix, and prevent the plant from falling over.

[0069] In some embodiments, the particle size distribution is controlled to be 0.5-2 mm by adjusting the amount of water added. The particle size distribution can be precisely controlled by adjusting the amount of water added to meet the cultivation needs of different plants.

[0070] A third aspect of an embodiment of the present application provides an application of steel slag fine powder planting sand, wherein the planting sand is used for soilless cultivation of orchid plants, including Dendrobium officinale and Phalaenopsis.

[0071] The application of the steel slag fine powder planting sand provided in the third aspect of the embodiment of the present application, because the provided planting sand has high air permeability and moderate water retention, can perfectly match the root requirements of orchid plants such as Dendrobium officinale and Phalaenopsis, and significantly improve the survival rate and growth rate; at the same time, it can replace traditional substrates such as peat and vermiculite, solve their problems of easy pulverization and uneven quality, and is conducive to soilless cultivation and promotes the development of green agriculture.

[0072] In some embodiments, the planting sand needs to be regularly supplemented with fertilizer or nutrient solution during use to maintain the nutrients required for plant growth; and the planting sand can be reused multiple times, and the overall cost is lower than that of peat substrate.

[0073] The following describes the details in conjunction with specific embodiments.

[0074] Example 1

[0075] A kind of steel slag fine powder planting sand and its preparation method and application

[0076] (1) Weigh 100 parts of steel slag fine powder, 10 parts of bentonite, 5 parts of glass powder, 5 parts of phosphate rock powder, 5 parts of pore-forming agent, 5 parts of potassium chloride and 1 part of sodium lignin sulfonate, and mix them in a blender until ready for use;

[0077] (2) pouring the mixture obtained in step (1) into a ceramic sand granulator, and weighing 15 parts of water into the granulator, and granulating at a speed of 2000 r / min;

[0078] (3) Place the prepared granules in a drying oven at 70°C for drying;

[0079] (4) The dried particles were sintered at 900°C for 20 minutes to obtain planting sand. The prepared planting sand had a crushing rate of 22% under a cylinder pressure strength of 28 MPa, a particle size of 0.5-1 mm, a water retention rate of 63%, and a bulk density of 1150 kg / m 3 .

[0080] (5) Take 400 g of the above-prepared planting sand and spread it in two 500 mL flower pots, transplant Dendrobium officinale and Phalaenopsis into the planting sand respectively, add 150 mL of water every 3 days, and observe and record the growth of Dendrobium officinale and Phalaenopsis.

[0081] Example 2

[0082] A kind of steel slag fine powder planting sand and its preparation method and application

[0083] (1) Weigh 100 parts of steel slag fine powder, 5 parts of kaolin, 10 parts of glass powder, 5 parts of phosphate rock powder, 15 parts of pore-forming agent, 5 parts of potassium chloride and 1.5 parts of polycarboxylate water-reducing agent, and mix them in a blender until ready for use;

[0084] (2) pouring the mixture obtained in step (1) into a ceramic sand granulator, and weighing 20 parts of water into the granulator, and granulating at a speed of 2500 r / min;

[0085] (3) Place the prepared granules in a drying oven at 100°C for drying;

[0086] (4) The dried particles were sintered at 850°C for 30 min to obtain planting sand. The prepared planting sand was tested to have a crushing rate of 20% under a cylinder pressure strength of 28 MPa, a particle size of 1-1.5 mm, a water retention rate of 65%, and a pressure of 1200 kg / m 3 .

[0087] (5) Take 400 g of the above-prepared planting sand and spread it in two 500 mL flower pots, transplant the Dendrobium officinale and Phalaenopsis into the planting sand, add 150 mL of water every 3 days, and observe and record the growth of Dendrobium officinale and Phalaenopsis.

[0088] Example 3

[0089] A kind of steel slag fine powder planting sand and its preparation method and application

[0090] (1) Weigh 100 parts of steel slag fine powder, 15 parts of glass powder, 0.5 parts of naphthalene-based high-efficiency water reducer, 5 parts of phosphate rock powder, 10 parts of potassium chloride, and 10 parts of pore-forming agent, and mix them in a blender until ready for use;

[0091] (2) pouring the mixture obtained in step (1) into a ceramic sand granulator, and weighing 25 parts of water into the granulator, and granulating at a speed of 3000 r / min;

[0092] (3) Place the prepared granules in a drying oven at 120°C for drying;

[0093] (4) The dried particles were sintered at 800°C for 40 minutes to obtain planting sand. The prepared planting sand was tested to have a crushing rate of 23% under a cylinder pressure strength of 28 MPa, a particle size of 1.5-2 mm, a water retention rate of 61%, and a water content of 1100 kg / m 3 .

[0094] (5) Take 400 g of the above-prepared planting sand and spread it in two 500 mL flower pots, transplant the Dendrobium officinale and Phalaenopsis into the planting sand, add 150 mL of water every 3 days, and observe and record the growth of Dendrobium officinale and Phalaenopsis.

[0095] Comparative Example 1

[0096] Place 400g of peat in a 500mL pot and transplant each Dendrobium officinale into the soil. Add 150mL of water every three days and observe and record the growth of the Dendrobium officinale under the same conditions. Plant height is the distance from the stem base to the highest point of its natural extension, and stem diameter is the stem diameter 10cm above the stem base.

[0097] Comparative Example 2

[0098] Place 400g of peat in a 500mL pot, transplant the Phalaenopsis orchid into the soil, and add 150mL of water every three days. Observe and record the growth of the orchid under the same conditions. Plant height is the distance from the base of the stem to the highest point of its natural extension, and stem diameter is the stem diameter 10cm above the base.

[0099] Property Test

[0100] (1) The planting sand obtained in Examples 1 to 3 was tested for particle size, capacity, water retention rate and 28 MPa cylinder pressure strength crushing rate.

[0101] (2) The growth conditions of the Dendrobium officinale of Examples 1 to 3 and Comparative Example 1 were analyzed.

[0102] (3) The growth conditions of the Phalaenopsis orchids of Examples 1 to 3 and Comparative Example 2 were analyzed.

[0103] Result Analysis

[0104] (1) The planting sands obtained in Examples 1 to 3 were tested for particle size, capacity, water retention rate, and 28 MPa cylinder pressure strength crushing rate. As shown in Table 1, the properties of the planting sands obtained in Examples 1 to 3 are all very beneficial. Specifically, the comprehensive performance of Example 2 is the best, with a bulk density (1200 kg / m 3 ) was the highest, water retention was the best (65%), and breakage was the lowest (20%), indicating that medium-sized particles (1-1.5 mm) achieved the best balance between density, pore structure, and compressive strength. High bulk density indicates closer contact between particles and a stable structure, which is beneficial for anchoring plant roots. High water retention and uniform surface pore distribution retain water while preventing water accumulation, meeting the needs of orchids. High compressive strength indicates an optimized sintering process, reducing internal defects in the particles.

[0105] Table 1

[0106]

[0107] (2) The growth of the Dendrobium officinale of Examples 1 to 3 and Comparative Example 1 was analyzed. As shown in Table 2, it can be seen that the plant height of the Dendrobium officinale in the planting sand prepared in each embodiment increased by 9-10 cm 35 days before and after transplanting, and the stem diameter increased by 0.5-0.51 cm 35 days before and after transplanting. The plant height of the Dendrobium officinale in Comparative Example 1 increased by 3 cm 35 days before and after transplanting, and the stem diameter increased by 0.24 cm 35 days before and after transplanting. This shows that the planting sand prepared in the present invention is more effective in planting Dendrobium officinale than peat, and can be used as a soilless culture medium for planting Dendrobium officinale.

[0108] Table 2

[0109]

[0110] (3) The growth of the Phalaenopsis orchids of Examples 1 to 3 and Comparative Example 2 was analyzed. As shown in Table 3, it can be seen that the Phalaenopsis orchids in the planting sand prepared in each embodiment increased in plant height by 19-21 cm 30 days before and after transplanting, and increased in stem diameter by 1.51-1.69 cm 30 days before and after transplanting. The Phalaenopsis orchids in Comparative Example 2 increased in plant height by 13 cm 30 days before and after transplanting, and increased in stem diameter by 0.43 cm 30 days before and after transplanting. This shows that the planting sand prepared in the present invention is better than peat in planting Phalaenopsis orchids, and can be used as a soilless culture medium for planting Phalaenopsis orchids.

[0111] Table 3

[0112]

[0113] In summary, the steel slag fine powder planting sand provided in the embodiment of the present application uses steel slag fine powder as the main raw material, effectively utilizes steelmaking by-products, reduces environmental pollution, and reduces raw material costs. By adding pore-forming agents and glass powder to form a uniform porous structure, it has both high air permeability and water and fertilizer retention capabilities, meeting the strict air permeability requirements of the roots of orchid plants; in addition, it also includes phosphate rock powder and potassium chloride to provide the phosphorus and potassium elements necessary for plants, reduce initial nutrient solution dependence, and promote plant growth; the provided planting sand is more suitable for planting orchid plants with high requirements for air permeability of the root system, and as a soilless cultivation substrate to replace peat, its advantages of large pores and not easy to pulverize are more obvious, and the planting effect is better; and, because the steel slag fine powder planting sand has good hardness and can be reused many times, the comprehensive cost of the steel slag fine powder planting sand is lower than that of most soilless planting substrates such as peat, which is conducive to wide application.

[0114] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A steel slag fine powder seeding sand, characterized in that: The composition comprises the following components in parts by weight: 100 parts of steel slag fine powder, 5-20 parts of glass powder, Plasticizer 0-10 parts, 0.5-2 parts of water reducing agent, 15-30 parts water, 5-30 parts of pore-forming agent, 5-10 parts of phosphate rock powder, 5-10 parts of potassium chloride.

2. The steel slag fine powder seeding sand according to claim 1, characterized in that: The particle size of the steel slag fine powder is 50 to 100 μm; The particle size of the glass powder is 10 to 20 μm; The particle size of the phosphate rock powder and potassium chloride is 50-100 μm.

3. The steel slag fine powder seeding sand according to claim 1, characterized in that: The plasticizer is selected from one or more of calcined kaolin, bentonite, white clay or ball clay; The water reducer is selected from one or more of lignin sulfonate water reducers, naphthalene water reducers, and melamine water reducers; The pore-forming agent is selected from one or more of graphite, carbon powder, starch and organic fiber.

4. The steel slag fine powder seeding sand according to claim 1, characterized in that: The steel slag fine powder seeding sand has a porous structure, a particle size of 0.1 to 2 mm, and a bulk density of 1100 to 1200 kg / m 3 , the water retention rate is 61% to 65%.

5. A method for preparing steel slag fine powder seeding sand according to any one of claims 1 to 4, characterized in that: The following steps are involved: Weigh steel slag powder, glass powder, plasticizer, phosphate rock powder, potassium chloride, pore former and water reducer according to the formula and mix them evenly; The mixture is poured into a granulator, and a prescribed amount of water is added, and granulation is performed at a speed of 1500-3500 r / min; the granulated particles are dried and sintered, and then cooled to obtain steel slag fine powder seeding sand.

6. The method for preparing steel slag fine powder seeding sand according to claim 5, characterized in that: The drying temperature is 50-120° C. and the drying time is 30 minutes.

7. The method for preparing steel slag fine powder seeding sand according to claim 5, characterized in that: The sintering process includes: heating from room temperature to 600-620°C at 20-40°C / min, then heating to 700-900°C at 10-30°C / min, and keeping the temperature for 10-30 minutes.

8. The method for preparing steel slag fine powder seeding sand according to claim 5, characterized in that: The particles formed by the granulation are spherical or irregular rhombus-shaped, and the particle size distribution is controlled to be 0.5-2 mm by adjusting the amount of water added.

9. An application of the steel slag fine powder seeding sand according to any one of claims 1 to 4, characterized in that: The planting sand is used for soilless cultivation of orchid plants, including Dendrobium officinale and Phalaenopsis.

10. The use according to claim 9, characterized in that The planting sand needs to be regularly supplemented with fertilizer or nutrient solution during use to maintain the nutrients required for plant growth; and the planting sand can be reused multiple times, and the overall cost is lower than that of peat substrate.

Images