Harbor industry solid waste-based cargo storage yard pavement base material and preparation method thereof

Abstract

The invention relates to a road surface base material for a harbor industry solid waste-based cargo storage yard and a preparation method of the road surface base material, and belongs to the technical field of road engineering. The storage yard pavement base material is mainly composed of dredged mud and sand, broken stones, activated iron smelting waste residues, water, a solid waste-based cementing material and cement. The invention also provides a preparation method of the storage yard pavement base material. According to the method, solid waste resources in the port-near industrial park can be effectively utilized, and environmental pollution caused by solid waste stacking is reduced. And the low-value solid waste can be effectively utilized for green building material production, so that the green building material production cost is reduced. The carbon emission can be effectively reduced, and the development of green and low-carbon economy of the harbor industry is assisted.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and in particular to a pavement base material for a port-side industrial solid waste-based cargo yard and a preparation method thereof. Background Art

[0002] Port-related industries (such as waterway dredging, port construction, steelmaking, and shipbuilding) generate massive amounts of solid waste annually (such as steel slag, fly ash, marine dredged sand, and waste concrete) due to their extensive industrial activities. Traditional landfills or stockpiles pose challenges in land occupation, environmental pollution, and resource waste. In recent years, an increasing number of solid wastes have been utilized for higher-value applications. However, due to the complex composition (including salt, alkali, and heavy metals) and regional concentration of port-related solid waste, direct resource utilization presents technical bottlenecks. For example, salt corrosion and poor volume stability restrict its application in building materials.

[0003] Port yards are the core areas within port areas for storing and handling bulk cargo, including containers, and other open-air cargo. They primarily handle cargo turnover and loading and unloading. Due to the heavy loads, high-frequency vibrations, and salt spray corrosion, port yards require higher strength (≥6MPa), durability, and deformation resistance than typical pavement base materials.

[0004] Existing technologies mostly focus on the modification and application of a single solid waste. Few research results have been found for the coordinated disposal of multi-source solid waste near ports, or for adapting port yard base materials to the dual requirements of strength and environmental protection. There is an urgent need to develop low-cost pretreatment processes and stability control technologies to achieve the deep integration of large-scale solid waste disposal and green infrastructure. Existing traditional sand and gravel bases are expensive and non-renewable. However, bulk solid waste materials from port industries (such as iron smelting waste and dredged mud and sand) have lower crushing values ​​and higher wear resistance than traditional sand and gravel materials. As basic materials for port yard base construction, they are more effective than natural sand and gravel, and their application cost is lower. How to rationally utilize bulk solid waste materials from port industries is an urgent issue that needs to be addressed. Summary of the Invention

[0005] In view of the technical problem that the existing bulk solid waste materials of port-based industries cannot be reasonably utilized, the present invention provides a port-based industry solid waste-based cargo yard pavement base material and a preparation method thereof to solve the above problem.

[0006] The technical solutions of the present invention are as follows: In the first aspect, the present invention provides a solid waste-based cargo yard pavement base material for port industries, wherein the yard pavement base material is mainly composed of dredged mud and sand, gravel, activated iron smelting waste slag, water, solid waste-based cementitious material, and cement.

[0007] Furthermore, the base material for the storage yard pavement includes the following components per cubic meter by weight: 1,000-1,300 kg of dredged mud and sand, 200-500 kg of crushed stone, 700-1,000 kg of activated iron smelting waste slag, 100-150 kg of water, 50-70 kg of solid waste-based cementitious material, 50-70 kg of cement-1, and 10-20 kg of anti-expansion densifier. The solid waste-based cementitious material contains the following components per 100 kg by weight: 5-20 kg of cement-2, 10-20 kg of desulfurization ash, 5-20 kg of industrial by-product gypsum, 40-60 kg of cold-extracted furnace slag, 10-20 kg of activated iron smelting waste slag powder, 0-2 kg of activator, and 1-2 kg of alkali residue.

[0008] Iron smelting waste slag is soaked in seawater for 30 days and then screened. Slag with a particle size (D90) of 5 mm to 30 mm is activated and used as coarse aggregate in the yard pavement base material. Slag with a particle size (D90) less than 5 mm is dried at 100°C for 6 hours and then mechanically ground to form iron smelting slag powder in the solid waste-based cementitious material. This method utilizes the weak alkalinity of seawater to destroy the complete solid solution on the surface of the iron smelting waste slag and react with the free MgO and CaO that affect the stability of the iron smelting waste slag. Tidal fluctuations are then used to erode the surface of the stored iron smelting waste slag.

[0009] Furthermore, a grinding aid is added during mechanical grinding, wherein the grinding aid is at least one of triethanolamine, polycarboxylic acid-based grinding aid or triisopropanolamine, the grinding time is ≥70 min, and the specific surface area of ​​the iron smelting waste slag powder is ≥400 m 2 / kg.

[0010] Furthermore, the dredged mud and sand is a mixture of medium sea sand and fine sand, with a fineness modulus of 1.8~2.8, a mud content of <40%, a crushing value of <20%, and a mud block content of <5%.

[0011] Furthermore, the crushed stone is made of granite with a particle size of 10 to 30 mm and continuous grading.

[0012] Furthermore, the iron smelting waste slag is a crushed stone-like material obtained after crushing and sorting the iron smelting furnace slag, with a particle size of 10 to 25 mm and continuous grading.

[0013] Furthermore, the water is tap water, recycled water or sea water, with a salt content of less than 5%.

[0014] Furthermore, the alkali residue is chlor-alkali waste residue, wherein the alkali content in the alkali residue is not less than 40% in terms of sodium hydroxide.

[0015] Furthermore, the cement 1 and cement 2 are ordinary 42.5 silicate cement.

[0016] Furthermore, the activator is one or more of sodium sulfate, hydrated sodium silicate, sodium hydroxide, sodium carbonate, triethanolamine, triisopropanolamine, and sodium metabisulfite, which can stimulate the mechanical strength of the solid waste cementitious material and adjust the setting time. The anti-swelling densifier is one or more of tailings, bentonite, fly ash, and silica fume, which can densify the material structure to a certain extent and give the material self-repairing properties after expansion and cracking.

[0017] In a second aspect, the present invention provides a method for preparing the above-mentioned pavement base material, comprising the following steps: (1) Pretreatment of iron smelting waste slag Seawater immersion is used to accelerate the aging of iron smelting waste slag. The slag is immersed in seawater at a water-to-solids ratio of 2:1. The weak alkalinity of seawater destroys the complete solid solution on the slag surface and reacts with free MgO and CaO, which affect the slag's stability. Tidal fluctuations are used to erode the surface of the stockpiled slag. A single slag pretreatment cycle lasts 20-30 days.

[0018] (2) Screen the eroded iron smelting waste slag and retain the waste slag with a particle size of 5 to 30 mm for use as coarse aggregate in the base material of the yard pavement; retain the waste slag with a particle size of less than 5 mm and dry it at 100 ° C for 6 hours, then grind it mechanically and use it as the iron smelting slag powder in the solid waste-based cementitious material. The grinding time should be no less than 70 minutes, and the specific surface area of ​​the waste slag powder should be no less than 400 m 2 During the grinding process, a grinding aid may be added, wherein the grinding aid is at least one of triethanolamine, a polycarboxylic acid grinding aid or triisopropanolamine.

[0019] (3) Raw material measurement and batching After weighing each component, transfer it to a mixer and mix it evenly to obtain the pavement base material.

[0020] The beneficial effects of the present invention are: This invention can effectively utilize solid waste resources in Lingang Industrial Park, reducing environmental pollution caused by solid waste accumulation. It can also effectively utilize low-value solid waste to produce green building materials, thereby reducing the production cost of green building materials. It can effectively reduce carbon emissions and contribute to the development of a green, low-carbon economy in Lingang industries. DETAILED DESCRIPTION

[0021] In order to make the technical scheme in the present application better understood by the person skilled in the art, the technical scheme in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should fall within the protection scope of the present application.

[0022] Pretreatment of iron smelting slag The iron smelting slag is subjected to accelerated aging pretreatment by seawater soaking, and the soaking is performed at a water-solid volume ratio of 2:1. The single iron smelting slag pretreatment cycle is 30 days. After the soaking treatment, the iron smelting slag is subjected to baking treatment. The treated iron smelting slag is screened, and the iron smelting slag with a particle size of 5 mm to 30 mm is reserved for the preparation of the stockyard pavement base materials in Examples 3 to 8. The iron smelting slag with a particle size of <5 mm is reserved for the preparation of Samples One to Four in Example 1.

[0023] Example 1 The iron smelting slag with a particle size of <5 mm is dried at 100°C for 6 hours, and then mechanically ground to obtain Samples One to Four.

[0024] (1) Sample One: After baking, the iron smelting slag is placed in a ball mill, 0.04% triethanolamine by mass of the iron smelting slag is added as a grinding aid, the grinding time is set to 70 min, and after grinding, the specific surface area of the iron smelting slag is measured.

[0025] (2) Sample Two: After baking, the iron smelting slag is placed in a ball mill, 0.04% (triethanolamine + triisopropanolamine, ratio 1:1) by mass of the iron smelting slag is added as a grinding aid, the grinding time is set to 70 min, and after grinding, the specific surface area of the iron smelting slag is measured.

[0026] (3) Sample Three: After baking, the iron smelting slag is placed in a ball mill, 0.04% triisopropanolamine by mass of the iron smelting slag is added as a grinding aid, the grinding time is set to 70 min, and after grinding, the specific surface area of the iron smelting slag is measured.

[0027] (4) Sample Four: After baking, the iron smelting slag is placed in a ball mill, 0.04% polycarboxylate grinding aid by mass of the iron smelting slag is added as a grinding aid, the grinding time is set to 70 min, and after grinding, the specific surface area of the iron smelting slag is measured.

[0028] The specific surface areas of Samples One to Four are detected, and the specific detection results are shown in Table 1. Table 1 - Specific surface area detection results

[0029] Example 2 Preparation of solid waste-based cementitious material Sample one: the solid waste-based cementitious material contains the following components by weight per 1000 kg: cement II 200 kg, desulfurization ash 100 kg, industrial by-product gypsum 90 kg, cold leaching slag 400 kg, and activated ferrous slag powder (sample two of example 1) 190 kg. The mixing ratio of alkali residue and activator is 1:1, and the dosage is 20 kg.

[0030] Sample two: the solid waste-based cementitious material contains the following components by weight per 1000 kg: cement II 200 kg, desulfurization ash 100 kg, industrial by-product gypsum 190 kg, cold leaching slag 400 kg, and activated ferrous slag powder (sample two of example 1) 90 kg. The mixing ratio of alkali residue and activator is 1:1, and the dosage is 20 kg.

[0031] Sample three: the solid waste-based cementitious material contains the following components by weight per 1000 kg: cement II 200 kg, desulfurization ash 200 kg, industrial by-product gypsum 90 kg, cold leaching slag 400 kg, and activated ferrous slag powder (sample two of example 1) 90 kg. The mixing ratio of alkali residue and activator is 1:1, and the dosage is 20 kg.

[0032] Sample four: the solid waste-based cementitious material contains the following components by weight per 1000 kg: cement II 200 kg, desulfurization ash 100 kg, industrial by-product gypsum 90 kg, cold leaching slag 500 kg, and activated ferrous slag powder (sample two of example 1) 90 kg. The mixing ratio of alkali residue and activator is 1:1, and the dosage is 20 kg.

[0033] Sample five: the solid waste-based cementitious material contains the following components by weight per 1000 kg: cement II 100 kg, desulfurization ash 100 kg, industrial by-product gypsum 90 kg, cold leaching slag 600 kg, and activated ferrous slag powder (sample two of example 1) 90 kg. The mixing ratio of alkali residue and activator is 1:1, and the dosage is 20 kg.

[0034] Samples one to five are mixed uniformly to obtain solid waste-based cementitious material. The mechanical strength of the solid waste-based cementitious material is evaluated according to “GB / T 17671-2021 Cement Strength Test Methods (ISO Method)”, and the setting time of the solid waste-based cementitious material is evaluated according to “GB / T 1346-2011 Cement Standard Consistency Water Content, Setting Time, and Stability Test Methods”. The specific test results are shown in Table 2: Table 2 - Test results of solid waste-based cementitious material

[0035] Example 3 A method for preparing the above-mentioned road base material comprises the following steps: The yard pavement base material contains the following components by weight per cubic meter: 1100 kg of dredged sand, 800 kg of crushed stone, 400 kg of iron smelting waste, 120 kg of water, 60 kg of solid waste-based cementitious material (Sample 4 of Example 2), 60 kg of cement, and 15 kg of anti-expansion densifier. The materials are weighed using an electronic scale and then fed into a mixer for a controlled mixing time of 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0036] Example 4 A method for preparing the above-mentioned road base material comprises the following steps: The yard pavement base material contains the following components by weight per cubic meter: 1100 kg of dredged sand, 600 kg of crushed stone, 600 kg of iron smelting waste slag, 120 kg of water, 60 kg of solid waste-based cementitious material (Sample 4 of Example 2), 60 kg of cement, and 15 kg of anti-expansion densifier. The materials are weighed using an electronic scale and then transferred to a mixer for a controlled mixing time of 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0037] Example 5 A method for preparing the above-mentioned road base material comprises the following steps: The yard pavement base material contains the following components by weight per cubic meter: 1100 kg of dredged sand, 400 kg of crushed stone, 800 kg of iron smelting waste, 120 kg of water, 60 kg of solid waste-based cementitious material (Sample 4 of Example 2), 60 kg of cement, and 15 kg of anti-expansion densifier. The materials are weighed using an electronic scale and then fed into a mixer for a controlled mixing time of 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0038] Example 6 A method for preparing the above-mentioned road base material comprises the following steps: The yard pavement base material contains the following components by weight per cubic meter: 1100 kg of dredged sand, 200 kg of crushed stone, 1000 kg of iron smelting waste, 120 kg of water, 60 kg of solid waste-based cementitious material (Sample 4 of Example 2), 60 kg of cement, and 15 kg of anti-expansion densifier. The materials are weighed using an electronic scale and then transferred to a mixer for a controlled mixing time of 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0039] Example 7 A method for preparing the above-mentioned road base material comprises the following steps: Each cubic meter of the yard pavement base material contains the following components by weight: 1100 kg of dredged sand, 1200 kg of iron smelting waste, 120 kg of water, 60 kg of solid waste-based cementitious material (Sample 4 of Example 2), 60 kg of cement, and 15 kg of an anti-swelling densifier. The materials are weighed using an electronic scale and then fed into a mixer for 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0040] Example 8 A method for preparing the above-mentioned road base material comprises the following steps: The yard pavement base material contains the following components by weight per cubic meter: 1100 kg of dredged sand, 400 kg of crushed stone, 800 kg of iron smelting waste slag, 120 kg of water, 80 kg of solid waste-based cementitious material (Sample 4 of Example 2), 40 kg of cement, and 15 kg of anti-expansion densifier. The materials are weighed using an electronic scale and then transferred to a mixer for a controlled mixing time of 45 seconds. After uniform mixing, the mixture is discharged and transported to the construction site for construction.

[0041] Test Case According to the requirements of the standards "JTG 3441-2024 Test Procedure for Stabilized Materials of Inorganic Binders for Highway Engineering" and "JTG / T F20-2015 Technical Specifications for Construction of Highway Pavement Base", the pavement base materials prepared in Examples 3 to 8 were sampled twice at the construction site, and the average values ​​of the experimental results are shown in Table 3 below: Table 3-Pavement base material test results

[0042] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be readily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A base material for the pavement of a cargo yard based on solid waste from a port industry, characterized in that: The base material of the storage yard pavement is mainly composed of dredged mud and sand, crushed stone, activated iron smelting waste slag, water, solid waste-based cementitious materials, and cement.

2. The port industrial solid waste-based cargo yard pavement base material according to claim 1, characterized in that: The base material of the storage yard road surface comprises the following components by weight per cubic meter: 1000-1300 kg of dredged mud and sand, 200-500 kg of crushed stone, 700-1000 kg of activated iron smelting waste slag, 100-150 kg of water, 50-70 kg of solid waste-based cementitious material, 50-70 kg of cement-1, and 10-20 kg of anti-expansion densifier; wherein each 100 kg of solid waste-based cementitious material comprises the following components by weight: 5-20 kg of cement-2, 10-20 kg of desulfurization ash, 5-20 kg of industrial by-product gypsum, 40-60 kg of cold-extracted furnace slag, 10-20 kg of activated iron smelting waste slag powder, 0-2 kg of activator, and 1-2 kg of alkali residue; Among them, the iron smelting waste slag is soaked in seawater for 30 days and then screened. The iron smelting waste slag with a particle size of D90 = 5 mm ~ 30 mm is activated iron smelting waste slag and used as coarse aggregate in the base material of the yard pavement; the iron smelting waste slag with a particle size of D90 < 5 mm is dried at 100 ° C for 6 hours and then mechanically ground to be used as activated iron smelting waste slag powder in solid waste-based cementitious materials.

3. The port-side industrial solid waste-based cargo yard pavement base material according to claim 2, characterized in that: Grinding aids are added during mechanical grinding. The grinding aid is at least one of triethanolamine, polycarboxylic acid grinding aids or triisopropanolamine. The grinding time is ≥70 min, and the specific surface area of ​​the activated iron smelting waste slag powder is ≥400 m 2 / kg.

4. A port-side industrial solid waste-based cargo yard pavement base material according to claim 1 or 2, characterized in that: The dredged mud and sand is a mixture of medium sea sand and fine sand, with a fineness modulus of 1.8~2.8, a mud content of <40%, a crushing value of <20%, and a mud block content of <5%.

5. A port-side industrial solid waste-based cargo yard pavement base material according to claim 1 or 2, characterized in that: The crushed stone is made of granite with a particle size of 10 to 30 mm and continuous grading.

6. A port-side industrial solid waste-based cargo yard pavement base material according to claim 1 or 2, characterized in that: The activated iron smelting waste slag is a crushed stone-like material obtained after the iron smelting furnace slag is crushed and sorted, with a particle size of 10 to 25 mm and continuous grading.

7. A port-side industrial solid waste-based cargo yard pavement base material according to claim 1 or 2, characterized in that: The water is tap water, recycled water or sea water, and the salt content is less than 5%.

8. The base material for the pavement of a port-side industrial solid waste cargo yard according to claim 2, characterized in that: The alkali residue is chlor-alkali waste residue, wherein the alkali content in the alkali residue is not less than 40% calculated as sodium hydroxide.

9. The port-side industrial solid waste-based cargo yard pavement base material according to claim 2, characterized in that: The activator is one or more of sodium sulfate, hydrated sodium silicate, sodium hydroxide, sodium carbonate, triethanolamine, triisopropanolamine, and sodium metabisulfite. The activator can stimulate the mechanical strength of the solid waste agent cementitious material and adjust the setting time; the anti-expansion densifier is one or more of tailings, bentonite, fly ash, and silica fume.

10. A method for preparing a pavement base material according to claim 1 or 2, characterized in that: The following steps are involved: (1) Pretreatment of iron smelting waste slag The iron smelting waste slag is pretreated by immersing it in seawater at a water-solid volume ratio of 2:

1. The pretreatment cycle of a single iron smelting waste slag is 20 to 30 days. (2) Screen the eroded iron smelting waste slag and retain the iron smelting waste slag with a particle size of 5 to 30 mm for use as coarse aggregate in the base material of the yard road; retain the iron smelting waste slag with a particle size of less than 5 mm and dry it at 100 °C for 6 hours, then grind it mechanically to use it as activated iron smelting slag powder in solid waste-based cementitious materials; the grinding time should be no less than 70 min, and the specific surface area of ​​the iron smelting waste slag powder should be no less than 400 m 2 / kg; (3) Raw material measurement and batching After weighing each component, transfer it to a mixer and mix it evenly to obtain the pavement base material.

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