Environmentally friendly concrete admixture for recycling industrial waste residue and preparation method thereof

Abstract

The present invention relates to an environmentally friendly concrete admixture that recycles industrial waste slag and its preparation method. The method first modifies domestic waste incineration slag, significantly improving its strength and reducing its porosity while also reducing the leaching of heavy metal ions. The modified slag is then ground with lithium slag, phosphorus slag, titanium slag, and other materials to produce an environmentally friendly concrete admixture that recycles industrial waste slag with excellent performance. This environmentally friendly concrete admixture fully utilizes the synergistic and complementary effects of different types of slag and raw materials, achieving excellent shrinkage resistance from early to late stages of the composite admixture.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, in particular to an environmentally friendly concrete admixture that recycles industrial waste residue and a preparation method thereof. Background Art

[0002] In the concrete industry, admixtures, in addition to cement, have become an indispensable component of concrete. Commonly used admixtures are primarily based on high-quality slag powder and first-grade fly ash. However, due to the rapid development of infrastructure, the use of concrete is increasing, and higher crack resistance is required. High-quality admixtures such as fly ash and slag powder can no longer meet current demand. To reduce costs, expand the source of raw materials for admixtures, and protect the environment, the resource utilization of waste materials such as industrial waste and slag has become extremely urgent.

[0003] With the rapid development of urbanization in my country, the output of urban domestic waste is increasing day by day. How to deal with these long-accumulated domestic waste has become a major problem for the healthy development of cities. Incineration and comprehensive utilization of domestic waste are currently effective means to achieve waste reduction, harmlessness and resource utilization, with good social and environmental benefits. However, as the amount of domestic waste incineration increases, a large amount of solid waste incineration slag will be generated. Previous studies have found that the engineering properties of domestic waste incineration ash are similar to those of natural aggregates. It is mainly composed of slag, ferrous and non-ferrous metals, ceramic fragments, glass and some other non-combustible inorganic substances and incompletely burned organic matter. The main components are Ca, Si, Na, K, Fe, Al and some heavy metals.

[0004] While there are reports that municipal solid waste incineration slag can be used as a building material, unmodified municipal solid waste incineration slag has significant porosity and contains approximately 5% unburned organic matter, severely limiting its engineering properties as a building material. Furthermore, the high concentration of heavy metals in municipal solid waste incineration slag limits its efficient use. Therefore, converting municipal solid waste incineration slag into a recyclable, environmentally friendly concrete admixture has become a key research topic. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and provide an environmentally friendly concrete admixture that recycles industrial waste slag and a preparation method thereof, thereby turning waste into treasure, recycling resources, reducing production costs, expanding the source of raw materials for admixtures, and protecting the environment.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] The environmentally friendly concrete admixture made by recycling industrial waste slag is characterized in that the raw materials of the environmentally friendly concrete admixture made by recycling industrial waste slag include the following raw materials: lithium slag, phosphorus slag, titanium slag and modified domestic waste incineration slag;

[0008] Furthermore, the lithium slag includes but is not limited to lithium slag produced during the preparation of lithium carbonate by sulfuric acid method;

[0009] Furthermore, the titanium slag includes waste slag obtained by cooling the slag discharged during the smelting of vanadium-titanium magnetite in a blast furnace;

[0010] Furthermore, the phosphorus slag includes solid waste residue produced by preparing yellow phosphorus by electric furnace method;

[0011] Furthermore, the environmentally friendly concrete admixture made from recycled industrial waste residues comprises, by weight, 30-70 parts of modified domestic waste incineration slag, 10-20 parts of lithium slag, 15-30 parts of phosphorus slag, and 10-20 parts of titanium slag;

[0012] Furthermore, the environmentally friendly concrete admixture made by recycling industrial waste residues includes 40-60 parts of modified domestic waste incineration slag, 10-20 parts of lithium slag, 15-30 parts of phosphorus slag, 12-18 parts of titanium slag,

[0013] Furthermore, the environmentally friendly concrete admixture recycled from industrial waste residues comprises 50 kg of modified domestic waste incineration slag, 10 kg of lithium slag, 25 kg of phosphorus slag, and 15 kg of titanium slag;

[0014] Furthermore, the environmentally friendly concrete admixture that recycles industrial waste residues also includes a composite abrasive; the raw materials of the composite abrasive include triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone and water;

[0015] Furthermore, the weight ratio of triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone and water is 12-16:6-10:3-7:60-70, preferably 14:8:5:65;

[0016] Furthermore, the environmentally friendly concrete admixture made from recycled industrial waste residues comprises, by weight, 30-70 parts of modified domestic waste incineration slag, 10-20 parts of lithium slag, 15-30 parts of phosphorus slag, 10-20 parts of titanium slag, and 0.8-1.2 parts of a composite abrasive;

[0017] Furthermore, the preparation method of the modified domestic waste incineration slag includes:

[0018] Step S1: drying the domestic waste incineration slag, then feeding the dried domestic waste incineration slag into a grinder for grinding, and then feeding the ground domestic waste incineration slag into a rotary drum screen for screening, and screening the obtained slag;

[0019] Step S2: taking the screened material, sodium sulfide, light-burned magnesium oxide, and magnesium chloride and feeding them into a high-temperature calcining furnace for calcining; after the screened material is completely melted, dispersing them into water for rapid cooling; and then drying the product obtained after rapid cooling again to obtain modified domestic waste incineration slag;

[0020] Furthermore, in step S1, the specific conditions for drying are: drying at 105-115° C. for 6-10 hours;

[0021] Furthermore, the pore size of the sieve is 0.5-1.5 mm;

[0022] Furthermore, in step S2, the screened material is 80-120 parts, the sodium sulfide is 1-3 parts, the light-burned magnesium oxide is 3-7 parts, and the magnesium chloride is 3-7 parts, by weight;

[0023] Furthermore, the calcination temperature is 750-850°C;

[0024] Furthermore, the specific conditions for drying are: drying at 105-115° C. for 6-10 hours.

[0025] Furthermore, in step S2, the screened material is 90-110 parts, the sodium sulfide is 1-3 parts, the light-burned magnesium oxide is 4-6 parts, and the magnesium chloride is 4-6 parts in parts by weight.

[0026] Furthermore, the method comprises the following steps: placing lithium slag, phosphorus slag, titanium ore slag and modified domestic waste incineration slag in a ball mill, adding a composite grinding agent and ball milling the ball milled product until the specific surface area of ​​the ball milled product is 550 to 600 m 2 / kg, an environmentally friendly concrete admixture is obtained.

[0027] Beneficial effects:

[0028] The present invention first modifies municipal solid waste incineration slag, significantly improving its strength and reducing the leaching of heavy metal ions. This slag is then ground with lithium slag, phosphorus slag, titanium slag, and other materials to produce an environmentally friendly concrete admixture that utilizes recycled industrial waste. This environmentally friendly concrete admixture leverages the synergistic and complementary effects of different types of slag and raw materials, achieving excellent shrinkage resistance from early to late stages of the composite admixture. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the following embodiments. Obviously, the embodiments described are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0030] Example 1

[0031] This embodiment provides an environmentally friendly concrete admixture that recycles industrial waste residue and a preparation method thereof. The specific steps are as follows:

[0032] Step S1: drying the domestic waste incineration slag at 110° C. for 8 hours, then feeding the dried domestic waste incineration slag into a grinder for grinding, and then feeding the ground domestic waste incineration slag into a rotary screen for screening, wherein the aperture of the screen is 1 mm, and screening to obtain an undersize product A;

[0033] Step S2: 100 kg of the screened material A, 2 kg of sodium sulfide, 5 kg of light-burned magnesium oxide, and 5 kg of magnesium chloride are placed in a high-temperature calcining furnace for calcination at 800° C. After the screened material is completely melted, it is immediately dispersed into ice water for rapid cooling. The product obtained after rapid cooling is then dried again at 110° C. for 8 hours to obtain modified domestic waste incineration slag;

[0034] Step S3: triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone (K30, produced by Tianjin Hainachuan Technology Development Co., Ltd.) and water are stirred and dissolved at room temperature in a weight ratio of 14:8:5:65 to obtain a composite grinding aid; then 50 kg of modified domestic waste incineration slag, 10 kg of lithium slag, 25 kg of phosphorus slag, 15 kg of titanium slag and 1 kg of the composite grinding aid are put into a ball mill for ball milling, and the specific surface area is controlled at 550 to 600 m 2 / kg, and you get an environmentally friendly concrete admixture.

[0035] Example 2

[0036] This embodiment provides an environmentally friendly concrete admixture that recycles industrial waste and a preparation method thereof, and the specific steps are as follows:

[0037] Step S1: drying the domestic waste incineration slag at 110±5°C for 8 hours, then feeding the dried domestic waste incineration slag into a grinder for grinding, and then feeding the ground domestic waste incineration slag into a rotary screen for screening, wherein the aperture of the screen is 1 mm, and screening to obtain an undersize product A;

[0038] Step S2: 100 kg of the screened material A, 2 kg of sodium sulfide, 5 kg of light-burned magnesium oxide, and 5 kg of magnesium chloride are placed in a high-temperature calcining furnace for calcination at 800° C. After the screened material is completely melted, it is immediately dispersed into ice water for rapid cooling. The product obtained after rapid cooling is then dried again at 110±5° C. for 8 hours to obtain modified domestic waste incineration slag;

[0039] Step S3: triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone (K30, produced by Tianjin Hainachuan Technology Development Co., Ltd.) and water are stirred and dissolved at room temperature in a weight ratio of 14:8:5:65 to obtain a composite grinding aid; then 40 kg of modified domestic waste incineration slag, 20 kg of lithium slag, 25 kg of phosphorus slag, 15 kg of titanium slag and 1 kg of the composite grinding aid are put into a ball mill for ball milling, and the specific surface area is controlled at 550 to 600 m 2 / kg, and you get an environmentally friendly concrete admixture.

[0040] Example 3

[0041] This embodiment provides an environmentally friendly concrete admixture that recycles industrial waste and a preparation method thereof, and the specific steps are as follows:

[0042] Step S1: drying the domestic waste incineration slag at 110±5°C for 8 hours, then feeding the dried domestic waste incineration slag into a grinder for grinding, and then feeding the ground domestic waste incineration slag into a rotary screen for screening, wherein the aperture of the screen is 1 mm, and screening to obtain an undersize product A;

[0043] Step S2: 100 kg of the screened material A, 2 kg of sodium sulfide, 5 kg of light-burned magnesium oxide, and 5 kg of magnesium chloride are placed in a high-temperature calcining furnace for calcination at 800° C. After the screened material is completely melted, it is immediately dispersed into ice water for rapid cooling. The product obtained after rapid cooling is then dried again at 110±5° C. for 8 hours to obtain modified domestic waste incineration slag;

[0044] Step S3: triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone (K30, produced by Tianjin Hainachuan Technology Development Co., Ltd.) and water are stirred and dissolved at room temperature in a weight ratio of 14:8:5:65 to obtain a composite grinding aid; then 60 kg of modified domestic waste incineration slag, 10 kg of lithium slag, 15 kg of phosphorus slag, 15 kg of titanium slag and 1 kg of the composite grinding aid are put into a ball mill for ball milling, and the specific surface area is controlled at 550 to 600 m 2 / kg, and you get an environmentally friendly concrete admixture.

[0045] Comparative Example 1:

[0046] Compared with Example 1, the only difference is that "5 kg of light-burned magnesia" is not added in step S2.

[0047] Comparative Example 2:

[0048] Compared with Example 1, the only difference is that: step S2 does not add "5 kg of magnesium chloride".

[0049] Comparative Example 3:

[0050] Triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone (K30, produced by Tianjin Hainachuan Technology Development Co., Ltd.) and water are stirred and dissolved at room temperature in a weight ratio of 14:8:5:65 to obtain a composite grinding aid; 10 kg of lithium slag, 15 kg of phosphorus slag, 15 kg of titanium slag and 1 kg of composite grinding aid are put into a ball mill for ball milling, and the specific surface area is controlled at 550-600 m 2 / kg, and obtain environmentally friendly concrete admixture.

[0051] Application Examples

[0052] According to Appendix A of Composite Admixtures for Concrete JG / T 486-2015, the 7d activity index, 28d activity index and fluidity ratio of the composite mineral admixture were tested at a mass ratio of 8:2 between cement and the environmentally friendly concrete admixtures in Examples 1-3 and Comparative Example 1. The results are shown in Table 1.

[0053] According to GB / T 17671-2021, the mortar specimens were molded in a 7:3 mass ratio of cement to the environmentally friendly concrete admixtures in Examples 1-3 and Comparative Example 1. A 40mm×40mm×160mm triple steel mold was used to form the mortar specimens. The two end plates of the mold had three 6mm blind holes. Before molding, a round-headed copper rod probe with a length of 2.5cm and a diameter of 6mm was placed. After molding, the surface was covered with a layer of plastic wrap and placed in a standard curing room at a curing temperature of (20±3)℃ and a relative humidity of more than 90%. The mold was removed after curing for 1 day. The initial value of the specimen length was measured with a screw micrometer (unit: mm, accurate to 0.001mm); the specimen was moved into a constant temperature and humidity chamber (curing temperature (20±2)℃, relative humidity 60%±5%) to test the length of the specimen at the beginning of curing and 28 days, respectively, and its shrinkage rate was tested. The results are shown in Table 1.

[0054] Table 1 Test results

[0055] 7d activity index / % 28d activity index / % Mobility ratio 28d shrinkage Example 1 88 97 105 97 Example 2 82 94 103 94 Example 3 79 93 101 92 Comparative Example 1 73 88 92 115 Comparative Example 2 70 84 90 120 Comparative Example 3 58 69 82 137

[0056] The mineral composite mineral admixture prepared according to the present invention can meet the requirements of 7d activity index ≥79%, 28d activity index ≥93%, and fluidity ratio ≥101%, which are all better than those of comparative examples 1-3. At the same time, its 28d shrinkage rate is also significantly reduced compared with the sample of comparative example 1 (without mineral admixture), which can effectively reduce the shrinkage of the matrix material and is beneficial to improving the ability of cement-based materials to resist shrinkage cracking.

[0057] The above is a detailed introduction to the environmentally friendly concrete admixture that recycles industrial waste slag and its preparation method provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scopes. However, any equivalent modifications or changes made by ordinary technical personnel in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. An environmentally friendly concrete admixture that recycles industrial waste residue, characterized in that: The raw materials include lithium slag, phosphorus slag, titanium slag and modified domestic waste incineration slag; the preparation method of the modified domestic waste incineration slag includes: Step S1: drying the domestic waste incineration slag, then feeding the dried domestic waste incineration slag into a grinder for grinding, and then feeding the ground domestic waste incineration slag into a rotary drum screen for screening, and screening the obtained slag; Step S2: taking the screened material, sodium sulfide, light-burned magnesium oxide, and magnesium chloride and feeding them into a high-temperature calcining furnace for calcining; after the screened material is completely melted, dispersing them into water for rapid cooling; and then drying the product obtained after rapid cooling again to obtain modified domestic waste incineration slag; The environmentally friendly concrete admixture recycled from industrial waste also includes a composite abrasive; the raw materials of the composite abrasive include triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone and water; the weight ratio of the triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone and water is 12-16:6-10:3-7:60-70; The raw materials of the environmentally friendly concrete admixture made by recycling industrial waste slag include 30-70 parts of modified domestic waste incineration slag, 10-20 parts of lithium slag, 15-30 parts of phosphorus slag, 10-20 parts of titanium slag and 0.8-1.2 parts of composite abrasive in parts by weight.

2. The environmentally friendly concrete admixture made by recycling industrial waste according to claim 1, characterized in that: The weight ratio of the triethanolamine, sodium tripolyphosphate, polyvinyl pyrrolidone and water is 14:8:5:

65.

3. The environmentally friendly concrete admixture made from recycled industrial waste according to claim 1, characterized in that: In step S1, the specific conditions for drying are: drying at 105-115° C. for 6-10 hours; and / or the aperture of the sieve is 0.5-1.5 mm.

4. The environmentally friendly concrete admixture made from recycled industrial waste according to claim 1, characterized in that: In step S2, the screened material is 80-120 parts, the sodium sulfide is 1-3 parts, the light-burned magnesium oxide is 3-7 parts, and the magnesium chloride is 3-7 parts, by weight; and / or, the calcination temperature is 750-850° C.; And / or, the specific conditions of drying are: drying at 105-115° C. for 6-10 hours.

5. The environmentally friendly concrete admixture made by recycling industrial waste according to claim 1 is characterized by: In the step S2, the screened material is 90-110 parts, the sodium sulfide is 1-3 parts, the light-burned magnesium oxide is 4-6 parts, and the magnesium chloride is 4-6 parts by weight.

6. The method for preparing an environmentally friendly concrete admixture by recycling industrial waste according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: placing lithium slag, phosphorus slag, titanium ore slag and modified domestic waste incineration slag in a ball mill, adding a composite grinding agent and performing ball milling, and the specific surface area of ​​the product after ball milling is 550-600m 2 / kg, an environmentally friendly concrete admixture is obtained.