A high-volume smelting slag-based supersulfate cement for highways and its preparation method

Abstract

The present invention relates to the technical field of cement, and specifically to a high-volume smelting slag-based supersulfate cement for highways and a preparation method thereof. Industrial solid wastes such as smelting slag, alkali slag, desulfurized gypsum, and fly ash are selected as cement base materials. The smelting slag is pretreated and then co-ground with an auxiliary agent to obtain modified smelting slag. The lignosulfonate is modified. First, it undergoes a hydroxymethylation reaction with formaldehyde, and then a chloro intermediate prepared by grafting isopentenyl polyethylene glycol ether and epichlorohydrin is used to obtain a lignosulfonate-based polyether monomer. Then, it replaces a certain proportion of isopentenyl polyethylene glycol ether and undergoes free radical polymerization with acrylic acid to prepare a lignosulfonate-based branched modified polycarboxylic acid as a composite lignosulfonate. Furthermore, carboxyl-hydroxy esterification is utilized to graft a bio-based ultraviolet absorber polyhydroxy epicatechin derivative.

Description

Technical Field

[0001] The present invention relates to the technical field of cement, and specifically to a high-bleed smelting slag-based supersulfate cement for highways and a preparation method thereof. Background Art

[0002] In road engineering construction, cement is the main cementitious material for roadbeds, bases, concrete, etc. However, the production of traditional cement involves high carbon emissions and is not conducive to environmental protection.

[0003] Smelting slag is an industrial by-product of industrial iron and steelmaking, generally including blast furnace slag, converter slag, electric arc furnace slag, etc. It mostly contains a large amount of heavy metal ions and has poor hydration activity. Directly used as a cementitious material for road engineering, it has low strength. Under the action of water, temperature, and load, the dissolved heavy metal ions are likely to affect the surrounding area of the road. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-bleed smelting slag-based supersulfate cement for highways and a preparation method thereof to solve the problems in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A high-bleed smelting slag-based supersulfate cement for highways, calculated by mass, the raw material components of the cement are: 100 parts of modified smelting slag powder, 15 - 35 parts of composite alkali slag powder, 5 - 10 parts of desulfurized gypsum, 3 - 10 parts of fly ash, 10 - 25 parts of iron tailing sand, and 1 - 2 parts of water reducer.

[0007] Further, the preparation of the composite alkali slag powder includes the following steps:

[0008] Centrifuge, dry, disperse, and grind the alkali slag sand to obtain alkali slag sand particles, and then mix them with white mud and salt mud that have been pressure-filtered and dried in a mass ratio of (5 - 10):(65 - 85):(10 - 25), ball mill for 30 - 90 min, and perform powder selection to obtain the composite alkali slag powder.

[0009] Further, the preparation of the modified smelting slag powder includes the following steps:

[0010] Grind and crush blast furnace slag and converter slag powder, sieve to obtain blast furnace slag particles and converter slag particles, compound the blast furnace slag particles and converter slag particles in a mass ratio of (60 - 85):(15 - 40) to obtain smelting slag particles; mix the smelting slag particles, grinding aid, and weak acid regulator, ball mill for 3 - 6 h to obtain smelting slag powder; mix the smelting slag powder and additives, ball mill at 80 - 140 °C for 15 - 30 min, and cool down to obtain the modified smelting slag powder.

[0011] Further, by mass parts, the composition of the smelting slag powder is: 100 parts of smelting slag particles, 0.03 - 0.1 part of grinding aid, and 0.5 - 0.9 part of weak acid regulator.

[0012] Further, the grinding aid is one of triethanolamine, ethylene glycol, glycerol, triisopropanolamine, diethanol monoisopropanolamine, and monoisopropanolamine.

[0013] Further, the weak acid regulator is one of formic acid, acetic acid, oxalic acid, citric acid, and tartaric acid.

[0014] Further, by mass parts, the composition of the modified smelting slag powder is: 100 parts of smelting slag powder and 0.1 - 0.2 part of auxiliary agent.

[0015] Further, the auxiliary agent is obtained by compounding polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxydiethylamine in a mass ratio of (10 - 25):(15 - 25):(10 - 30):(30 - 50).

[0016] Further, the water reducer is obtained by compounding lignosulfonate and aliphatic hydroxyl sulfonate polymer in a mass ratio of 1:1.

[0017] Further, the water reducer is modified lignosulfonate, and the preparation includes the following steps:

[0018] (1) Mix lignosulfonate and deionized water, add formaldehyde solution, adjust the pH of the solution to 10, keep it warm at 99 - 101 °C for 170 - 190 min, cool, concentrate, and dry to obtain hydroxymethylated lignosulfonate;

[0019] (2) Heat isopentenyl polyoxyethylene ether to melting, add boron trifluoride etherate and epichlorohydrin, keep it warm at 63 - 67 °C for 110 - 130 min, and perform vacuum distillation to obtain a chloro intermediate; mix hydroxymethylated lignosulfonate and deionized water, adjust the pH to 13, add the chloro intermediate, keep it warm at 75 - 85 °C for 2 - 3 h, add it to ethanol, concentrate, wash, and dry to obtain a lignosulfonate - based polyether monomer;

[0020] (3) Mix the lignosulfonate - based polyether monomer, isopentenyl polyoxyethylene ether, and deionized water, heat to 78 - 82 °C, add ammonium persulfate, stir for 10 - 15 min, add a mixed solution of acrylic acid, ascorbic acid, mercaptoethanol, and deionized water, keep it warm for 3 - 4 h, and adjust the pH of the solution to 7 to obtain a composite lignosulfonate.

[0021] (4) Mix the polyhydroxy epicatechin derivative and dimethyl sulfoxide, add a mixed solution of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, dimethyl sulfoxide, and compound lignosulfonate, perform ultrasonic treatment for 50 - 60 min, keep warm at 55 - 65 °C for 22 - 24 h, filter and wash with methanol 3 - 5 times, and dry to obtain the modified lignosulfonate.

[0022] Further, the auxiliary agent is obtained by compounding modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine in a mass ratio of (10 - 25) : (15 - 25) : (10 - 30) : (30 - 50).

[0023] Further, the preparation of the modified polydimethylsiloxane includes the following steps:

[0024] 1) Under a nitrogen atmosphere, mix 1,2-epoxy-4-vinylcyclohexane, Karstedt catalyst, and toluene, heat up to 78 - 82 °C, add a mixed solution of terminal hydrogen poly(dimethylsiloxane) and toluene, heat up to 98 - 102 °C and keep warm for 11 - 12 h, and perform vacuum distillation to obtain alicyclic epoxy group-containing polydimethylsiloxane;

[0025] 2) Mix the polyhydroxy epicatechin derivative and dimethyl sulfoxide, heat up to 65 - 75 °C, add alicyclic epoxy group-containing polydimethylsiloxane and diethyl tetrafluoroborate, keep warm for 2 - 3 h, add sodium carbonate, perform extraction and vacuum distillation to obtain the modified polydimethylsiloxane.

[0026] Further, the preparation of the polyhydroxy epicatechin derivative includes the following steps: Mix epicatechin, p-hydroxybenzoic acid, and methanesulfonic acid, transfer to a water bath at 38 - 42 °C and keep warm for 110 - 130 min, cool, pour into an ice-water mixture, perform vacuum filtration, wash successively with sodium bicarbonate solution and deionized water until the pH is neutral, perform vacuum filtration and freeze-dry, use a silica gel column for separation and purification with a petroleum ether and ethyl acetate eluent with a volume ratio of 3:1, and perform rotary evaporation to obtain the polyhydroxy epicatechin derivative.

[0027] Further, a preparation method of a high-amount-smelting-slag-based supersulfate cement for roads includes the following steps: Mix the modified smelting slag powder, compound alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand, and water reducer, and perform ball milling to obtain a high-amount-smelting-slag-based supersulfate cement for roads.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The present invention provides a high-volume smelting slag-based supersulfate cement for highways and a preparation method. Through composition and process limitations, a high-volume smelting slag-based supersulfate cement with the properties of sealing heavy metal ions, good crack resistance, excellent ultraviolet resistance, and resistance to deicing salt erosion is prepared, contributing to the low-carbon construction of road projects.

[0030] In the present invention, industrial solid wastes such as smelting slag, alkali slag, desulfurized gypsum, and fly ash are selected as cement base materials, which turns waste into treasure, achieves the purpose of cost reduction and efficiency increase, and has important environmental, economic, and social benefits. In the present invention, the smelting slag is first pretreated and then co-ground with additives to obtain modified smelting slag. The gelling activity of the smelting slag is activated by alkali and salt, and the heavy metal ions in the smelting slag are sealed by ion chelation and polyester modification to avoid environmental pollution caused by the dissolution of heavy metals, which is conducive to the large-scale utilization of smelting slag solid waste and alleviates the pressure of solid waste storage.

[0031] In the present invention, lignosulfonate and aliphatic hydroxy sulfonate polymer are compounded as water reducers. In order to improve the compatibility of the water reducer with other admixtures and gel materials and avoid phenomena such as bleeding and segregation in application, the lignosulfonate is modified to optimize its function. First, it reacts with formaldehyde for hydroxymethylation reaction to prepare hydroxymethylated lignosulfonate. The increase in hydroxyl content improves its water solubility, and then it grafts the chloro intermediate prepared from isopentenyl polyethylene glycol ether and epichlorohydrin to obtain lignosulfonate-based polyether monomer. Then, it replaces a certain proportion of isopentenyl polyethylene glycol ether and undergoes free radical polymerization with acrylic acid to prepare lignosulfonate-based branched modified polycarboxylic acid as a composite lignosulfonate, endowing the water reducer with stronger dispersibility and dispersion stability. Then, carboxyl-hydroxy esterification is used to graft the bio-based ultraviolet absorber polyhydroxy epicatechin derivative, which improves the durability of the cement while enhancing the dispersibility of the water reducer. The polyhydroxy epicatechin derivative is prepared from the bio-based raw material epicatechin and p-hydroxybenzoic acid.

[0032] In the process of modifying the smelting slag in the present invention, co-grinding with additives is adopted for modification, and modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine are compounded as additives. In order to improve the reaction activity of polydimethylsiloxane, the polydimethylsiloxane is modified. First, alicyclic epoxy polydimethylsiloxane is prepared from 1,2-epoxy-4-vinylcyclohexane and terminal hydrogen poly(dimethylsiloxane), and then it grafts the polyhydroxy epicatechin derivative under the catalysis of the catalyst diethyl borofluoride, synergistically improving the ultraviolet resistance of the cement, enhancing the durability of the sealing of heavy metal ions in the smelting slag, and improving the safety of cement use. Specific embodiments

[0033] The following will clearly and completely describe the technical solutions in the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0034] It should be noted that if there are directional indications such as up, down, left, right, front, and back in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] The following further elaborates on the technical solutions of the present invention in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0036] Embodiment 1: A preparation method of a high-volume smelting slag-based supersulfate cement for highways, comprising the following steps: mixing modified smelting slag powder, composite alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand, and water reducer, and then ball milling to obtain a high-volume smelting slag-based supersulfate cement for highways;

[0037] By mass, the raw material components of the cement are: 100 parts of modified smelting slag powder, 35 parts of composite alkali slag powder, 10 parts of desulfurized gypsum, 10 parts of fly ash, 25 parts of iron tailings sand, and 1.8 parts of water reducer;

[0038] The preparation of the composite alkali slag powder includes the following steps:

[0039] Centrifuging, drying, dispersing, and grinding the alkali slag sand to obtain alkali slag sand particles, and then mixing them with white mud and salt mud that have been pressure-filtered and dried in a mass ratio of 10:65:25, ball milling for 90 min, and then separating powder to obtain the composite alkali slag powder;

[0040] The preparation of the modified smelting slag powder includes the following steps:

[0041] Grinding and crushing blast furnace slag and converter slag powder, screening to obtain blast furnace slag particles and converter slag particles, compounding the blast furnace slag particles and converter slag particles in a mass ratio of 75:25 to obtain smelting slag particles; mixing the smelting slag particles, grinding aid, and weak acid regulator, ball milling for 5 h to obtain smelting slag powder; mixing the smelting slag powder and additives, ball milling at 100 °C for 20 min, and then cooling to obtain the modified smelting slag powder;

[0042] In terms of parts by mass, the composition of the smelting slag powder is: 100 parts of smelting slag particles, 0.05 part of grinding aid, and 0.6 part of weak acid regulator; the grinding aid is triethanolamine; the weak acid regulator is acetic acid; in terms of parts by mass, the composition of the modified smelting slag powder is: 100 parts of smelting slag powder and 0.2 part of auxiliary agent;

[0043] The auxiliary agent is obtained by compounding polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine in a mass ratio of 10:20:25:45;

[0044] The water reducing agent is obtained by compounding lignosulfonate and aliphatic hydroxy sulfonate polymer in a mass ratio of 1:1.

[0045] Example 2: A preparation method of a high-volume smelting slag-based supersulfate cement for roads, comprising the following steps: mixing modified smelting slag powder, composite alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand, and water reducing agent, and ball milling to obtain a high-volume smelting slag-based supersulfate cement for roads;

[0046] In terms of parts by mass, the raw material components of the cement are: 100 parts of modified smelting slag powder, 15 parts of composite alkali slag powder, 5 parts of desulfurized gypsum, 3 parts of fly ash, 10 parts of iron tailings sand, and 1 part of water reducing agent;

[0047] The preparation of the composite alkali slag powder includes the following steps:

[0048] Centrifuging, drying, dispersing, and grinding the alkali slag sand to obtain alkali slag sand particles, and then mixing the alkali slag sand particles with white mud and salt mud that have been pressure filtered and dried in a mass ratio of 10:65:25, ball milling for 30 min, and separating powder to obtain the composite alkali slag powder;

[0049] The preparation of the modified smelting slag powder includes the following steps:

[0050] Grinding and crushing blast furnace slag and converter slag powder, sieving to obtain blast furnace slag particles and converter slag particles, compounding the blast furnace slag particles and converter slag particles in a mass ratio of 60:40 to obtain smelting slag particles; mixing the smelting slag particles, grinding aid, and weak acid regulator, ball milling for 3 h to obtain smelting slag powder; mixing the smelting slag powder and auxiliary agent, ball milling at 80 °C for 30 min, and cooling to obtain the modified smelting slag powder;

[0051] In terms of parts by mass, the composition of the smelting slag powder is: 100 parts of smelting slag particles, 0.03 part of grinding aid, and 0.5 part of weak acid regulator; the grinding aid is triethanolamine; the weak acid regulator is acetic acid; in terms of parts by mass, the composition of the modified smelting slag powder is: 100 parts of smelting slag powder and 0.1 part of auxiliary agent;

[0052] The water reducing agent is modified lignosulfonate, and its preparation includes the following steps:

[0053] (1) Mix 3.2 g of lignosulfonate with 20 mL of deionized water, add 2 mL of formaldehyde solution with a mass concentration of 37%, adjust the pH of the solution to 10, keep it warm at 99 °C for 190 min, cool, concentrate, and dry to obtain hydroxymethylated lignosulfonate;

[0054] (2) Heat 1 mmol of isopentenyl polyoxyethylene ether until it melts, add 0.02 g of boron trifluoride etherate and 1.2 mmol of epichlorohydrin, keep it warm at 63 °C for 130 min, and carry out vacuum distillation to obtain a chloro intermediate; Mix 2 g of hydroxymethylated lignosulfonate with 50 mL of deionized water, adjust the pH to 13, add 1.2 g of the chloro intermediate, keep it warm at 75 °C for 3 h, add it to 500 mL of ethanol, concentrate, wash, and dry to obtain a lignosulfonate-based polyether monomer;

[0055] (3) Mix 2 g of lignosulfonate-based polyether monomer, 8 g of isopentenyl polyoxyethylene ether, and 90 mL of deionized water, heat to 78 °C, add 1 g of ammonium persulfate, stir for 10 min, and successively add a mixture of 6 g of acrylic acid and 20 mL of deionized water, a mixture of 2 g of ascorbic acid, 3 g of mercaptoethanol, and 18 mL of deionized water, keep it warm for 3 h, and adjust the pH of the solution to 7 to obtain a composite lignosulfonate;

[0056] (4) Mix 1.8 g of polyhydroxy epicatechin derivative with 47 mL of dimethyl sulfoxide, add a mixture of 4 mL of N,N'-dicyclohexylcarbodiimide, 4 mL of 4-dimethylaminopyridine, 24 mL of dimethyl sulfoxide, and 4.6 g of composite lignosulfonate, carry out ultrasonic treatment for 50 min, keep it warm at 55 °C for 24 h, filter and wash with methanol 3 times, and dry to obtain a modified lignosulfonate;

[0057] The auxiliary agent is obtained by compounding modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine in a mass ratio of 10:20:25:45. The preparation of the modified polydimethylsiloxane includes the following steps:

[0058] 1) Under a nitrogen atmosphere, mix 22 g of 1,2-epoxy-4-vinylcyclohexane, 8 μL of Karstedt catalyst, and 13 mL of toluene, heat to 78 °C, add a mixture of 16 g of terminal hydrogen poly(dimethylsiloxane) and 13 mL of toluene, heat to 98 °C and keep it warm for 12 h, and carry out vacuum distillation to obtain an alicyclic epoxy group-containing polydimethylsiloxane;

[0059] 2) Mix 2.5 g of polyhydroxy epicatechin derivative with 50 mL of dimethyl sulfoxide, heat to 65 °C, add 4.2 g of alicyclic epoxy group-containing polydimethylsiloxane and 67 mg of diethylboron tetrafluoride, keep it warm for 2 h, add 0.1 g of sodium carbonate, extract and carry out vacuum distillation to obtain a modified polydimethylsiloxane;

[0060] The preparation of the polyhydroxy epicatechin derivative comprises the following steps: Mix 2.5 mmol of epicatechin, 3 mmol of p-hydroxybenzoic acid, and 35 mmol of methanesulfonic acid, transfer the mixture to a water bath at 38 °C for heat preservation for 130 min, cool it, pour it into 5 mL of an ice-water mixture, perform vacuum filtration, wash it successively with a sodium bicarbonate solution and deionized water until the pH is neutral, perform vacuum filtration and freeze-drying, and separate and purify it by silica gel column using petroleum ether and ethyl acetate with a volume ratio of 3:1 as the eluent, and perform rotary evaporation to obtain the polyhydroxy epicatechin derivative.

[0061] Example 3: A preparation method of a high-bleed slag-based supersulfate cement for roads comprises the following steps: Mix modified slag powder, composite alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand, and water reducer, and perform ball milling to obtain a high-bleed slag-based supersulfate cement for roads;

[0062] By mass, the raw material components of the cement are: 100 parts of modified slag powder, 25 parts of composite alkali slag powder, 6 parts of desulfurized gypsum, 8 parts of fly ash, 20 parts of iron tailings sand, and 1.8 parts of water reducer;

[0063] The preparation of the composite alkali slag powder comprises the following steps:

[0064] Centrifuge, dry, disperse, and grind the alkali slag sand to obtain alkali slag sand particles, and then mix them with white mud and salt mud that have been pressure-filtered and dried in a mass ratio of 5:70:25, perform ball milling for 60 min, and perform powder selection to obtain the composite alkali slag powder;

[0065] The preparation of the modified slag powder comprises the following steps:

[0066] Grind and crush blast furnace slag and converter slag powder, sieve them to obtain blast furnace slag particles and converter slag particles, compound the blast furnace slag particles and converter slag particles in a mass ratio of 75:25 to obtain slag particles; Mix the slag particles, grinding aid, and weak acid regulator, perform ball milling for 4 h to obtain slag powder; Mix the slag powder and additives, perform ball milling at 100 °C for 20 min, and cool down to obtain the modified slag powder;

[0067] By mass, the composition of the slag powder is: 100 parts of slag particles, 0.05 part of grinding aid, and 0.6 part of weak acid regulator; The grinding aid is triethanolamine; The weak acid regulator is acetic acid; By mass, the composition of the modified slag powder is: 100 parts of slag powder and 0.2 part of additive;

[0068] The water reducer is a modified lignosulfonate, and its preparation comprises the following steps:

[0069] (1) Mix 3.2 g of lignosulfonate with 20 mL of deionized water, add 2 mL of formaldehyde solution with a mass concentration of 37%, adjust the pH of the solution to 10, keep it warm at 100 °C for 180 min, cool, concentrate, and dry to obtain hydroxymethylated lignosulfonate;

[0070] (2) Heat 1 mmol of isopentenyl polyoxyethylene ether until it melts, add 0.02 g of boron trifluoride etherate and 1.2 mmol of epichlorohydrin, keep it warm at 65 °C for 120 min, and perform vacuum distillation to obtain a chloro intermediate; Mix 2 g of hydroxymethylated lignosulfonate with 50 mL of deionized water, adjust the pH to 13, add 1.2 g of the chloro intermediate, keep it warm at 80 °C for 2.5 h, add it to 500 mL of ethanol, concentrate, wash, and dry to obtain a lignosulfonate-based polyether monomer;

[0071] (3) Mix 2 g of lignosulfonate-based polyether monomer, 8 g of isopentenyl polyoxyethylene ether, and 90 mL of deionized water, heat to 80 °C, add 1 g of ammonium persulfate, stir for 13 min, and sequentially add a mixture of 6 g of acrylic acid and 20 mL of deionized water, a mixture of 2 g of ascorbic acid, 3 g of mercaptoethanol, and 18 mL of deionized water, keep it warm for 3.5 h, and adjust the pH of the solution to 7 to obtain a composite lignosulfonate;

[0072] (4) Mix 1.8 g of polyhydroxy epicatechin derivative with 47 mL of dimethyl sulfoxide, add a mixture of 4 mL of N,N'-dicyclohexylcarbodiimide, 4 mL of 4-dimethylaminopyridine, 24 mL of dimethyl sulfoxide, and 4.6 g of composite lignosulfonate, perform ultrasonic treatment for 55 min, keep it warm at 60 °C for 23 h, filter and wash with methanol 4 times, and dry to obtain a modified lignosulfonate;

[0073] The auxiliary agent is prepared by compounding modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine in a mass ratio of 10:20:25:45. The preparation of the modified polydimethylsiloxane includes the following steps:

[0074] 1) Under a nitrogen atmosphere, mix 22 g of 1,2-epoxy-4-vinylcyclohexane, 8 μL of Karstedt catalyst, and 13 mL of toluene, heat to 80 °C, add a mixture of 16 g of terminal hydrogen poly(dimethylsiloxane) and 13 mL of toluene, heat to 100 °C and keep it warm for 11.5 h, and perform vacuum distillation to obtain an alicyclic epoxy group-containing polydimethylsiloxane;

[0075] 2) Mix 2.5 g of polyhydroxy epicatechin derivative with 50 mL of dimethyl sulfoxide, heat to 70 °C, add 4.2 g of alicyclic epoxy group-containing polydimethylsiloxane and 67 mg of diethyl borofluoride, keep it warm for 2.5 h, add 0.1 g of sodium carbonate, extract and perform vacuum distillation to obtain a modified polydimethylsiloxane;

[0076] The preparation of the polyhydroxy epicatechin derivative comprises the following steps: Mix 2.5 mmol of epicatechin, 3 mmol of p-hydroxybenzoic acid, and 35 mmol of methanesulfonic acid, transfer the mixture to a water bath at 40 °C and keep it warm for 120 min, cool it, pour it into 5 mL of an ice-water mixture, perform vacuum filtration, wash it successively with a sodium bicarbonate solution and deionized water until the pH is neutral, perform vacuum filtration again, freeze-dry it, separate and purify it by silica gel column chromatography using a petroleum ether and ethyl acetate eluent with a volume ratio of 3:1, and perform rotary evaporation to obtain the polyhydroxy epicatechin derivative.

[0077] Example 4: A preparation method of a high-amount-smelting-slag-based supersulfate cement for roads comprises the following steps: Mix modified smelting slag powder, composite alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand, and a water reducer, and perform ball milling to obtain a high-amount-smelting-slag-based supersulfate cement for roads;

[0078] By mass, the raw material components of the cement are: 100 parts of modified smelting slag powder, 35 parts of composite alkali slag powder, 10 parts of desulfurized gypsum, 10 parts of fly ash, 25 parts of iron tailings sand, and 2 parts of water reducer;

[0079] The preparation of the composite alkali slag powder comprises the following steps:

[0080] Centrifuge, dry, disperse, and grind the alkali slag sand to obtain alkali slag sand particles, then mix them with white mud and salt mud that have been pressure-filtered and dried in a mass ratio of 8:70:22, perform ball milling for 90 min, and perform powder selection to obtain the composite alkali slag powder;

[0081] The preparation of the modified smelting slag powder comprises the following steps:

[0082] Grind and crush blast furnace slag and converter slag powder, sieve them to obtain blast furnace slag particles and converter slag particles, compound the blast furnace slag particles and converter slag particles in a mass ratio of 85:15 to obtain smelting slag particles; Mix the smelting slag particles, grinding aid, and weak acid regulator, perform ball milling for 6 h to obtain smelting slag powder; Mix the smelting slag powder and an auxiliary agent, perform ball milling at 140 °C for 15 min, and cool down to obtain the modified smelting slag powder;

[0083] By mass, the composition of the smelting slag powder is: 100 parts of smelting slag particles, 0.1 part of grinding aid, and 0.9 part of weak acid regulator; The grinding aid is triethanolamine; The weak acid regulator is acetic acid; By mass, the composition of the modified smelting slag powder is: 100 parts of smelting slag powder, 0.15 part of auxiliary agent;

[0084] The water reducer is a modified lignosulfonate, and its preparation comprises the following steps:

[0085] (1) Mix 3.2 g of lignosulfonate with 20 mL of deionized water, add 2 mL of formaldehyde solution with a mass concentration of 37%, adjust the pH of the solution to 10, keep it warm at 101 °C for 170 min, cool, concentrate, and dry to obtain hydroxymethylated lignosulfonate;

[0086] (2) Heat 1 mmol of isopentenyl polyoxyethylene ether until it melts, add 0.02 g of boron trifluoride etherate and 1.2 mmol of epichlorohydrin, keep it warm at 67 °C for 110 min, and carry out vacuum distillation to obtain a chloro intermediate; Mix 2 g of hydroxymethylated lignosulfonate with 50 mL of deionized water, adjust the pH to 13, add 1.2 g of the chloro intermediate, keep it warm at 85 °C for 2 h, add it to 500 mL of ethanol, concentrate, wash, and dry to obtain a lignosulfonate-based polyether monomer;

[0087] (3) Mix 2 g of lignosulfonate-based polyether monomer, 8 g of isopentenyl polyoxyethylene ether, and 90 mL of deionized water, heat to 82 °C, add 1 g of ammonium persulfate, stir for 15 min, and successively add a mixture of 6 g of acrylic acid and 20 mL of deionized water, and a mixture of 2 g of ascorbic acid, 3 g of mercaptoethanol, and 18 mL of deionized water, keep it warm for 4 h, and adjust the pH of the solution to 7 to obtain a composite lignosulfonate;

[0088] (4) Mix 1.8 g of polyhydroxy epicatechin derivative with 47 mL of dimethyl sulfoxide, add a mixture of 4 mL of N,N'-dicyclohexylcarbodiimide, 4 mL of 4-dimethylaminopyridine, 24 mL of dimethyl sulfoxide, and 4.6 g of composite lignosulfonate, perform ultrasonic treatment for 60 min, keep it warm at 65 °C for 22 h, filter and wash 5 times with methanol, and dry to obtain a modified lignosulfonate;

[0089] The auxiliary agent is obtained by compounding modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxy diethylamine in a mass ratio of 10:20:25:45. The preparation of the modified polydimethylsiloxane includes the following steps:

[0090] 1) Under a nitrogen atmosphere, mix 22 g of 1,2-epoxy-4-vinylcyclohexane, 8 μL of Karstedt catalyst, and 13 mL of toluene, heat to 82 °C, add a mixture of 16 g of terminal hydrogen poly(dimethylsiloxane) and 13 mL of toluene, heat to 102 °C and keep it warm for 11 h, and carry out vacuum distillation to obtain an alicyclic epoxy group-containing polydimethylsiloxane;

[0091] 2) Mix 2.5 g of polyhydroxy epicatechin derivative with 50 mL of dimethyl sulfoxide, heat to 75 °C, add 4.2 g of alicyclic epoxy group-containing polydimethylsiloxane and 67 mg of diethylboron tetrafluoride, keep it warm for 3 h, add 0.1 g of sodium carbonate, extract and carry out vacuum distillation to obtain a modified polydimethylsiloxane;

[0092] The preparation of the polyhydroxy epicatechin derivative comprises the following steps: Mix 2.5 mmol of epicatechin, 3 mmol of p-hydroxybenzoic acid, and 35 mmol of methanesulfonic acid, transfer them to a water bath at 42 °C and keep warm for 110 min, cool, pour into 5 mL of ice-water mixture, perform vacuum filtration, wash successively with sodium bicarbonate solution and deionized water until the pH is neutral, perform vacuum filtration and freeze-drying, separate and purify with silica gel column using petroleum ether and ethyl acetate with a volume ratio of 3:1 as the eluent, and perform rotary evaporation to obtain the polyhydroxy epicatechin derivative.

[0093] Comparative Example 1: Taking Example 1 as the control group, replace the modified smelting slag powder with smelting slag powder, and other processes are normal.

[0094] Comparative Example 2: Taking Example 3 as the control group, replace the modified lignosulfonate with sodium lignosulfonate, and other processes are normal.

[0095] Comparative Example 3: Taking Example 3 as the control group, replace the modified polydimethylsiloxane with hydrogen-terminated poly(dimethylsiloxane), and other processes are normal.

[0096] Sources of the raw materials used (only as a demonstration example):

[0097] Blast furnace slag: By mass fraction, the main chemical components are 45% calcium oxide, 30% silicon dioxide, 14% aluminum oxide, 8% magnesium oxide, and 3% iron oxide; Converter slag: By mass fraction, the main chemical components are 55% calcium oxide, 15% iron oxide, 15% silicon dioxide, 10% aluminum oxide, and 5% magnesium oxide; The main components of white mud are 20% sodium chloride, 20% calcium carbonate, 20% calcium hydroxide, and 40% calcium sulfate dihydrate; Salt mud: By mass fraction, the main components are 80% calcium sulfate dihydrate, 10% magnesium hydroxide, 3% sodium chloride, and 1% calcium chloride; Alkali residue sand: By mass fraction, the main components are 40% calcium hydroxide, 58% calcium carbonate, and 2% sodium chloride; Desulfurized gypsum (99%): Hubei Dongcao Chemical Technology Co., Ltd.; Fly ash A01085: Wuhan Jiyesheng Chemical Co., Ltd.; Isoamylenyl polyoxyethylene ether DY-YL-330: Nantong Deyi Chemical Co., Ltd.; Iron tailings sand (fineness modulus is 0.58): By mass fraction, the main components are 56.5% oxygen, 6.9% magnesium, 8.4% aluminum, 17.5% silicon, 2.6% potassium, 1.7% calcium, 4.6% iron, and 0.7% titanium; Terminal hydrogen poly(dimethylsiloxane) 0213: Hubei Shiteng Chemical Technology Co., Ltd.; Triethanolamine T108151, Lignosulfonate (sodium lignosulfonate) S140863, Boron trifluoride etherate B431395, Epichlorohydrin E108182, Acrylic acid A615488, Ascorbic acid A103533, Mercaptoethanol M301573, Dimethyl sulfoxide D103274, N,N'-Dicyclohexylcarbodiimide N420184, 4-Dimethylaminopyridine D109207, Isooctyl acrylate I303355, Tributyl phosphate T100707, Diethanolamine D110466, 1,2-Epoxy-4-vinylcyclohexane V102412, Karstedt catalyst K131673, Diethyl tetrafluoroborate T498340, Epicatechin E130023, p-Hydroxybenzoic acid H108508, Methanesulfonic acid M108501: Aladdin reagent; Acetic acid, Formaldehyde, Ammonium persulfate, Methanol, Toluene, Sodium carbonate, Sodium bicarbonate, Petroleum ether, Ethyl acetate, Analytically pure: Reagents of Sinopharm Group.

[0098] Performance test: The cement prepared in the examples and comparative examples was tested:

[0099] Compressive strength: The sample size was 40 mm × 40 mm × 160 mm. The sample was prepared according to 450 g of cement, 225 g of deionized water, and 1350 g of standard sand, and cured for 28 d under standard curing conditions. The compressive strength test was carried out with reference to GB / T 17671-2021.

[0100] Ultraviolet resistance: After the samples cured for 28 days are irradiated with ultraviolet light at 365 nm for 72 hours, the compressive strength is measured again. When the change rate of the compressive strength of the samples is within 0 - 1% (including 1%), it is considered qualified; otherwise, it is unqualified.

[0101] Pt 2+ , Cr 3+ , Cl - Leaching: The determination is carried out successively with reference to HJ 557–2010 "Horizontal Oscillation Method for Toxicity Leaching of Solid Waste", GB 5085.3-2007 "Identification Standard for Hazardous Wastes - Identification of Toxicity Characteristic Leaching Procedure" and GB / T 14848 "Groundwater Quality Standard". When the leaching concentration of Pt 2+ (mg / L) ≤ 0.01, it is considered qualified; when the leaching concentration of Pt 2+ ≤ 0.005, it is excellent; when the leaching concentration of Cr 3+ (mg / L) ≤ 0.005, it is considered qualified; when the leaching concentration of Cr 3+ ≤ 0.002, it is excellent; when the concentration of Cl - (mg / L) ≤ 250, it is considered qualified; when the concentration of Cl - ≤ 125, it is excellent. The results are shown in Table 1;

[0102] Table 1

[0103]

[0104] The present invention provides a high-volume smelting slag-based supersulfate cement for highways and a preparation method. Through composition and process limitations, a high-volume smelting slag-based supersulfate cement with the properties of sealing heavy metal ions, good crack resistance, excellent ultraviolet resistance, and resistance to deicing salt erosion is prepared, contributing to the low-carbon construction of road engineering.

[0105] Comparing Example 1 with Comparative Example 1, it can be seen that by pre-treating the smelting slag first and then co-grinding it with additives, the modified smelting slag is obtained, thereby improving the various properties of the cement.

[0106] Comparing Example 3 with Comparative Example 2, it can be seen that in order to improve the compatibility of the water reducer and other admixtures with the gel material and avoid phenomena such as bleeding and segregation in application, the lignosulfonate is modified to optimize its action efficiency. First, it reacts with formaldehyde for hydroxymethylation to prepare hydroxymethylated lignosulfonate. The increased hydroxyl content improves its water solubility. Then, it grafts the chloro intermediate prepared from isopentenyl polyethylene glycol ether and epichlorohydrin to obtain a lignosulfonate-based polyether monomer. Then, it replaces a certain proportion of isopentenyl polyethylene glycol ether and undergoes free radical polymerization with acrylic acid to prepare a lignosulfonate-based branched modified polycarboxylic acid as a composite lignosulfonate, endowing the water reducer with stronger dispersibility and dispersion stability. Then, carboxyl-hydroxy esterification is used to graft the bio-based ultraviolet absorber polyhydroxy epicatechin derivative, which improves the durability of cement while improving the dispersibility of the water reducer; among them, the polyhydroxy epicatechin derivative is prepared from the bio-based raw material epicatechin and p-hydroxybenzoic acid.

[0107] Comparing Example 3 with Comparative Example 3, it can be seen that in the process of modifying the smelting slag in the present invention, co-grinding with an auxiliary agent is adopted for modification, and a compound of modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxydiethylamine is selected as the auxiliary agent; in order to improve the reaction activity of polydimethylsiloxane, the polydimethylsiloxane is modified. First, using 1,2-epoxy-4-vinylcyclohexane and hydrogen-terminated poly(dimethylsiloxane) as raw materials, alicyclic epoxy group-containing polydimethylsiloxane is prepared. Then, under the catalysis of the catalyst diethyl borate tetrafluoride, it grafts the polyhydroxy epicatechin derivative to synergistically improve the anti-ultraviolet property of the cement, improve the durability of the encapsulation of heavy metal ions in the smelting slag, and improve the durability of the cement.

[0108] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made using the specification of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A high-dosage smelting slag-based supersulfate cement for highway use, characterized in that: The raw material components of cement are: 100 parts of modified smelting slag powder, 15-35 parts of composite alkali slag powder, 5-10 parts of desulfurized gypsum, 3-10 parts of fly ash, 10-25 parts of iron tailings sand, and 1-2 parts of water reducing agent by weight. The preparation of the modified smelting slag powder comprises the following steps: Grind and crush blast furnace slag and converter slag, sieve to obtain blast furnace slag particles and converter slag particles, mix the blast furnace slag particles and converter slag particles in a mass ratio of (60-85): (15-40) to obtain smelting slag particles; mix the smelting slag particles, a grinding aid, and a weak acid regulator, and ball mill for 3-6 hours to obtain smelting slag powder; mix the smelting slag powder and the additive, ball mill at 80-140° C. for 15-30 minutes, and cool to obtain modified smelting slag powder; The auxiliary agent is prepared by mixing polydimethylsiloxane, isooctyl acrylate, tributyl phosphate and dihydroxydiethylamine in a mass ratio of (10-25): (15-25): (10-30): (30-50).

2. The high-dosage smelting slag-based super-sulfated cement for highway use according to claim 1, characterized in that: The preparation of the composite alkali slag powder comprises the following steps: The alkali slag sand is centrifuged, dried, broken up and ground to obtain alkali slag sand particles, which are then mixed with the white mud and salt mud that have been filtered and dried in a mass ratio of (5-10): (65-85): (10-25), ball-milled for 30-90 minutes, and powdered to obtain composite alkali slag powder.

3. The high-dosage smelting slag-based super-sulfated cement for highway use according to claim 1, characterized in that: In the preparation of the modified smelting slag powder, the composition of the smelting slag powder is, by weight, 100 parts of smelting slag particles, 0.03-0.1 parts of grinding aids, and 0.5-0.9 parts of weak acid regulators; the grinding aid is one of triethanolamine, ethylene glycol, propylene glycol, triisopropanolamine, diethanol monoisopropanolamine, and monoisopropanolamine; the weak acid regulator is one of formic acid, acetic acid, oxalic acid, citric acid, and tartaric acid; the composition of the modified smelting slag powder is, by weight, 100 parts of smelting slag powder and 0.1-0.2 parts of additives.

4. The high-dosage smelting slag-based supersulfated cement for highway use according to claim 1, characterized in that: The water reducing agent is obtained by compounding lignin sulfonate and aliphatic hydroxy sulfonate polymer in a mass ratio of 1:

1.

5. The high-dosage smelting slag-based super-sulfated cement for highway use according to claim 1, characterized in that: The water reducing agent is a modified lignin sulfonate, and the preparation thereof comprises the following steps: (1) Mixing lignin sulfonate and deionized water, adding formaldehyde solution, adjusting the pH of the solution to 10, keeping the temperature at 99-101° C. for 170-190 minutes, cooling, concentrating, and drying to obtain hydroxymethylated lignin sulfonate; (2) heating the isopentyl polyoxyethylene ether until it is melted, adding boron trifluoride etherate and epichlorohydrin, keeping the temperature at 63-67°C for 110-130 minutes, and distilling under reduced pressure to obtain a chlorinated intermediate; mixing hydroxymethylated lignin sulfonate and deionized water, adjusting the pH to 13, adding the chlorinated intermediate, keeping the temperature at 75-85°C for 2-3 hours, adding to ethanol, concentrating, washing, and drying to obtain a lignin sulfonate-based polyether monomer; (3) Mixing lignin sulfonate-based polyether monomer, isopentyl polyoxyethylene ether, and deionized water, heating to 78-82° C., adding ammonium persulfate, stirring for 10-15 min, adding a mixed solution of acrylic acid, ascorbic acid, mercaptoethanol, and deionized water, keeping warm for 3-4 h, and adjusting the pH of the solution to 7 to obtain a composite lignin sulfonate; (4) Mix a polyhydroxy epicatechin derivative and dimethyl sulfoxide, add a mixed solution of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, dimethyl sulfoxide and composite lignin sulfonate, ultrasonically treat for 50-60 minutes, keep warm at 55-65°C for 22-24 hours, filter and wash with methanol for 3-5 times, and dry to obtain modified lignin sulfonate.

6. The high-dosage smelter slag-based super-sulfated cement for highway use according to claim 1, characterized in that: In the preparation of modified smelting slag powder, the auxiliary agent is modified polydimethylsiloxane, isooctyl acrylate, tributyl phosphate, and dihydroxydiethylamine in a mass ratio of (10-25): (15-25): (10-30): (30-50). The preparation of the modified polydimethylsiloxane includes the following steps: 1) Under nitrogen atmosphere, 1,2-epoxy-4-vinylcyclohexane, Karstedt catalyst and toluene are mixed, heated to 78-82°C, a mixture of hydrogen-terminated poly(dimethylsiloxane) and toluene is added, the temperature is raised to 98-102°C and kept for 11-12 hours, and vacuum distilled to obtain alicyclic epoxy polydimethylsiloxane; 2) Mix the polyhydroxy epicatechin derivative and dimethyl sulfoxide, raise the temperature to 65-75°C, add alicyclic epoxy polydimethylsiloxane and diethyl tetrafluoroborate, keep the temperature for 2-3 hours, add sodium carbonate, extract, and distill under reduced pressure to obtain modified polydimethylsiloxane.

7. A high-dosage smelting slag-based super-sulfated cement for highway use according to claim 5 or 6, characterized in that: The preparation of the polyhydroxy epicatechin derivative comprises the following steps: mixing epicatechin, p-hydroxybenzoic acid and methanesulfonic acid, transferring to a water bath at 38-42° C. and keeping warm for 110-130 minutes, cooling, pouring into an ice-water mixture, vacuum filtering, washing with a sodium bicarbonate solution and deionized water in sequence until the pH value is neutral, vacuum filtering, freeze drying, separating and purifying on a silica gel column using petroleum ether and ethyl acetate in a volume ratio of 3:1 as eluents, and rotary evaporating to obtain the polyhydroxy epicatechin derivative.

8. A method for preparing a high-dosage smelting slag-based supersulfated cement for highway use according to any one of claims 1 to 6, characterized in that: The following steps are involved: Modified smelting slag powder, composite alkali slag powder, desulfurized gypsum, fly ash, iron tailings sand and water reducing agent are mixed and ball-milled to obtain a high-dosage smelting slag-based super-sulfate cement for highways.

Images