Component proportion design method and production system for all-solid waste slag-based cementing material

Abstract

The invention discloses a component proportion design method and a production system of an all-solid waste slag-based cementing material, and relates to the technical field of concrete mix proportion. The method comprises the following steps: firstly, determining main chemical components of solid waste raw materials such as slag, a sulfate donor and an alkali activator through XRF spectrum analysis; then deriving a main chemical reaction equation of the system according to the target hydration product, and determining an optimal molar ratio of each key chemical component; converting the molar ratio relation into the optimal mass mixing ratio of the slag, the sulfate donor and the alkali activator by combining with the purity of the raw materials; and finally, doping a small amount of early strength agent (such as alkali metal or sulfate series) to meet different engineering requirements. The corresponding production system integrates online component detection, intelligent proportion calculation and automatic control functions, the proportion can be optimized in real time according to fluctuation of raw material components, and efficient, accurate and automatic production of materials is achieved. According to the invention, resource utilization of all solid waste raw materials is realized, and the design process is scientific and controllable.

Description

Technical Field

[0001] This invention relates to the field of concrete mix design technology, specifically to a method and production system for designing the mix proportions of a solid waste slag-based cementitious material. Background Technology

[0002] Traditional silicate cement is the most widely used cementitious material today, but its production process is energy-intensive and generates large carbon emissions. Utilizing industrial solid waste (such as slag, steel slag, and desulfurized gypsum) to replace or partially replace cement is an important way for the building materials industry to achieve green and low-carbon transformation. Among these, alkali-activated slag cementitious materials have become a research hotspot due to their excellent mechanical properties and low-carbon characteristics.

[0003] However, existing methods for designing mix proportions of alkali-activated or all-solid-waste cementitious materials have significant limitations. Currently widely used methods are mostly based on empirical trial mixing, heavily reliant on researchers' experience and numerous repetitive experiments, resulting in long development cycles and high costs. More importantly, industrial solid waste has a wide range of sources and its chemical composition fluctuates dramatically. Such empirical methods struggle to adapt to changes in raw material composition, leading to unstable product quality, unpredictable performance, and hindering large-scale reliable industrial applications. Furthermore, traditional methods typically use a single macroscopic parameter (such as alkali equivalent or water-cement ratio) as the core design indicator, neglecting the fact that hydration in cementitious systems is essentially a complex chemical reaction process involving multiple chemical oxides. They fail to reveal the synergistic effects between components from a stoichiometric perspective and cannot achieve precise control over the types of hydration products. This prevents the maximization of material performance potential and restricts the development of specific functions (such as early strength).

[0004] Therefore, there is an urgent need in this field for a scientific, precise, and universally applicable method for mix design that can guide the synergistic utilization of multi-source solid waste from the perspective of the nature of chemical reactions, solve the problem of performance instability caused by component fluctuations, and achieve on-demand design of material properties. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and production system for designing the component proportions of a solid waste slag-based cementitious material. By utilizing a highly generalized quantitative mathematical model, parallel reactions are integrated into a unified metrological framework to precisely design and control the distribution of a complex multi-component solid waste system.

[0006] To achieve the above objectives, this invention discloses a method for designing the composition ratio of a solid waste slag-based cementitious material, comprising the following steps: (1) The components of the solid waste early-strength slag-based cementitious material are classified according to slag, sulfate donor, alkali activator and early-strength agent; (2) XRF spectroscopy was used to determine the types and mass contents of the main chemical oxides in the slag, sulfate donor, and alkali activator; (3) Determine the target hydration products of the cementitious material system based on the main chemical components in the slag, sulfate donor, and alkali activator; (4) Based on the target hydration products and the main chemical components in slag, sulfate donor and alkali activator, derive the main chemical reaction equations of the system and determine the optimal molar ratio between the main chemical components required to achieve the reaction; (5) Based on the content of each raw material component measured in step (2), the optimal molar ratio relationship described in step (4) is converted into the optimal mass ratio between slag, sulfate donor and alkali activator. (6) Add different types of early strength agents to the basic mix proportion obtained in step (5) to obtain a solid waste early strength slag-based cementitious material suitable for different engineering requirements.

[0007] Preferably, in step (1), the slag is blast furnace slag, whose main chemical components are SiO2, Al2O3, CaO and MgO, which will activate gelling activity in an alkaline environment. Preferably, the sulfate donor is a solid waste material containing sulfate ions, which is one or a mixture of desulfurized gypsum, desulfurized ash, phosphogypsum, and fluorogypsum, with the main chemical component being CaSO4·2H2O, and is a good sulfate donor. Alkaline activators are calcium-containing alkaline solid waste materials, such as carbide slag, whose main chemical component is Ca(OH)2, which is strongly alkaline and provides calcium.

[0008] Preferably, in step (2), the mass fractions of SiO2, Al2O3, CaO, and MgO in the slag are respectively a % , b % , c % and d % The mass fraction of CaSO4·2H2O in the sulfate donor is: e % The mass fraction of Ca(OH)2 in the alkaline activator is f % .

[0009] Preferably, the target hydration products in step (3) are 3CaO·2SiO2·3H2O, 4CaO·Al2O3·13H2O, 3CaO·Al2O3·3CaSO4·32H2O, and 5MgO·Al2O3·13H2O, wherein CSH is the final hydration product of SiO2 in the slag under alkaline conditions, and C4AH 13 AFt is the final hydration product of Al2O3 in slag under alkaline conditions and in the absence of sulfate donors, while M5AH is the final hydration product of Al2O3 in slag under alkaline conditions and in the presence of sufficient sulfate donors.13 This is the final hydration product of MgO in slag under alkaline conditions. The final hydration product of Al2O3 is mainly AFt, which promotes the early strength development of cementitious materials.

[0010] Preferably, in step (4), the main chemical reaction equation is: 2 x SiO2+( y+z+u Al2O3+5 u MgO+(3 x +4 y +3 z Ca(OH)2+3 z CaSO4+(9 y +29 z +13 u H2O→ x CSH+ y C4AH 13 + z AFt+ u M5AH 13 in, x、y、z、u The balancing coefficients in the chemical reaction equations are CSH and C4AH. 13 The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O.

[0011] Preferably, in step (4), the optimal molar ratio is 2 among SiO2, Al2O3, MgO, Ca(OH)2, and CaSO4. x :( y+z+u ): 5 u :(3 x +4 y +3 z ): 3 z .

[0012] Preferably, in step (5), the optimal mass ratio of slag, sulfate donor, and alkali activator in the all-solid-waste early-strength slag-based cementitious material can be determined by the content of each major chemical component in the slag, sulfate donor, and alkali activator, as shown below: S1. Establish calculation benchmark: Use 1g of slag as the benchmark unit for calculation; S2, Molar conversion: Based on the content of each raw material component in step (2), calculate the number of moles of each reactant that 1g of slag can provide; S3. Set targets for hydration products; S4. Calculate the external raw material requirements: Based on the optimal molar ratio in step (4), calculate the molar amounts of calcium sulfate and calcium hydroxide required to completely react with 1 gram of slag components. S5. Deduct the portion of slag self-supply: Since slag itself contains CaO, this portion needs to be subtracted from the total demand to obtain the net demand for Ca(OH)2 that must be provided by an external alkali activator. S6. Mass Conversion and Raw Material Conversion: Convert the required quantity of pure chemical substances into mass, and then perform the final conversion based on the purity of the actual raw materials. S7. Obtain the final mass ratio: After the above steps, the mass of sulfate donor and alkali activator precisely matched to 1 gram of slag is obtained, and the optimal mass ratio calculation formula is derived: Slag : Sulfate donor : Alkali activator = eff : f ( 5.06 b -2.58 d ): e (1.85 a +2.18 b -1.11 d -1.32 c ).

[0013] Preferably, in step (6), the early strength agent is an alkali metal-based early strength agent, and its dosage is 0.01%-0.07% of the slag mass. The alkali metal-based early strength agent contains Li... + Since plasma does not participate in the hydration reaction and does not change the types of hydration products, it does not change the chemical reaction equation, and the optimal mass ratio of slag, sulfate donor, and alkali activator remains unchanged. eff : f ( 5.06 b -2.58 d ): e (1.85 a +2.18 b -1.11 d -1.32 c LiOH·H2O can better promote the early strength development of cementitious materials with high Al phase content, and is suitable for use in slag where the Al2O3 content is higher than the SiO2 content and the seepage prevention requirements are generally low.

[0014] Preferably, in step (6), the early-strength agent is a sulfate-based early-strength agent, wherein SO4 in the sulfate-based early-strength agent... 2- It will react with the base activator. In step (4), the main chemical reaction equation is: 4 x SiO2+2( y+z+u Al2O3+10 u MgO+ (6 x+8 y+ 6 z+v )Ca(OH)2+(6 zv CaSO4+ v Na2SO4+ (18) y +58 z +26 UV H2O→2 x CSH+2 y C4AH 13 +2 z AFt+2 u M5AH 13 +2 v NaOH in, x、y、z、u、v —Balancing coefficients in chemical reaction equations, CSH is 3CaO2·2SiO2·3H2O, C4AH 13 The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O.

[0015] Preferably, in step (4), the optimal molar ratio is 4:1 among SiO2, Al2O3, MgO, Ca(OH)2, CaSO4, and Na2SO4. x :2( y + z + u ): 10 u :(6 x +8 y +6 z + v ):(6 z - v ): v .

[0016] Preferably, in step (5), the actual dosage of the sulfate-based early-strength agent is [amount]% of the slag mass. i The optimal mass mix ratio is calculated as: slag : sulfate donor : alkali activator = eff : f ( 5.06 b -2.58 d -1.21 i ): e (1.85 a +2.18 b -1.11 d +0.52 i -1.32 cNa2SO4 early strength agent can simultaneously promote the reaction of Al2O3 and SiO2, improve the hardened strength and permeability of cementitious materials, and resist the erosion of corrosive sulfates. It is suitable for use in slag where the Al2O3 content is less than or equal to the SiO2 content and the anti-seepage requirements are high.

[0017] This invention also provides a production system for all-solid waste slag-based cementitious materials, including an XRF online detection element, an intelligent proportioning calculation and control center, a raw material fine pretreatment and conveying unit, and a high uniformity mixing and stirring unit. The intelligent proportioning calculation and control center is used to implement the above-mentioned all-solid waste slag-based cementitious material composition proportioning design method, receive real-time raw material chemical composition data fed back from the XRF online detection element in the raw material silo, automatically calculate the optimal mass proportion of the current batch of raw materials, determine the required early strength agent type based on the real-time mass ratio of Al2O3 to SiO2 in the slag, and generate control commands to regulate the feeding rate of each raw material conveying unit and the feeding amount of the metering scale. The high-uniformity mixing unit is a twin-shaft paddle-type zero-gravity mixer. Its mixing speed and time are dynamically adjusted according to the fineness and moisture content of the raw materials to be mixed. The specific control formula is as follows: N = k 1×( SSA ) -1 / 2 ×(1+ ω ) -1 / 3 t = k 2×( SSA ) ×(1+ ω ) In the formula: N Optimized speed for the mixer, RPM; t The optimal mixing time is expressed in seconds (s); SSA represents the specific surface area of ​​the slag, in meters (m²). 2 / kg; ω The mass-weighted average moisture content of all materials in the system, % / 100; k 1, k 2 is an empirical coefficient.

[0018] Therefore, the present invention, employing the above-mentioned method for designing the composition ratio of a solid waste slag-based cementitious material and its production system, has the following beneficial effects: 1. The design method of this invention utilizes various bulk industrial solid wastes such as slag, desulfurization gypsum, and carbide slag to prepare high-efficiency cementitious materials, promoting the high-value synergistic utilization of multi-source solid wastes, with significant economic and environmental benefits; 2. The production system of this invention, based on the real-time dynamic adjustment capability of the proportioning design model and the refined and intelligent control of the entire process, effectively solves the problem of performance instability caused by fluctuations in the composition of solid waste raw materials, and ensures the reliability of cementitious materials. 3. It reduces reliance on traditional cement clinker, thereby reducing carbon emissions and energy consumption in the cement production process, and has the advantages of being green, low-carbon, and sustainable. 4. The corresponding production system integrates online component detection, intelligent proportion calculation and automatic control functions, which can optimize the proportion in real time according to the fluctuation of raw material composition, and realize efficient, accurate and automated production of materials. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for designing the component proportions of a solid waste slag-based cementitious material according to the present invention; Figure 2 This invention relates to a production system for early-strength slag-based cementitious materials made entirely from solid waste. Detailed Implementation

[0020] like Figure 1 As shown, this invention provides a method for designing the component proportions of a solid waste slag-based cementitious material, comprising the following steps: (1) The components of the solid waste early strength slag-based cementitious materials are classified according to slag, sulfate donor, alkali activator and early strength agent.

[0021] (2) XRF spectroscopy was used to determine the types and mass content of the main chemical oxides in the slag, sulfate donor, and alkali activator.

[0022] (3) Determine the target hydration products of the cementitious material system based on the main chemical components in the slag, sulfate donor, and alkali activator.

[0023] (4) Based on the target hydration products and the main chemical components in slag, sulfate donor and alkali activator, derive the main chemical reaction equation of the system and determine the optimal molar ratio between the main chemical components required to achieve the reaction.

[0024] (5) Based on the content of each raw material component measured in step (2), the optimal molar ratio described in step (4) is converted into the optimal mass ratio between slag, sulfate donor and alkali activator.

[0025] (6) Add different types of early strength agents to the basic mix proportion obtained in step (5) to obtain a solid waste early strength slag-based cementitious material suitable for different engineering requirements.

[0026] In step (1), the slag is blast furnace slag, whose main chemical components are SiO2, Al2O3, CaO and MgO, which will activate gelation activity in an alkaline environment.

[0027] The sulfate donor is a solid waste material containing sulfate ions, which is one or a mixture of desulfurized gypsum, desulfurized ash, phosphogypsum, and fluorogypsum. Its main chemical component is CaSO4·2H2O, and it is a good sulfate donor.

[0028] Alkaline activators are calcium-containing alkaline solid waste materials, such as carbide slag, whose main chemical component is Ca(OH)2, which is strongly alkaline and provides calcium.

[0029] In step (2), the mass fractions of SiO2, Al2O3, CaO, and MgO in the slag are respectively a % , b % , c % and d % The mass fraction of CaSO4·2H2O in the sulfate donor is: e % The mass fraction of Ca(OH)2 in the alkaline activator is f % .

[0030] In step (3), the target hydration products are 3CaO·2SiO2·3H2O, 4CaO·Al2O3·13H2O, 3CaO·Al2O3·3CaSO4·32H2O, and 5MgO·Al2O3·13H2O, where CSH is the final hydration product of SiO2 in the slag under alkaline conditions, and C4AH 13 AFt is the final hydration product of Al2O3 in slag under alkaline conditions and in the absence of sulfate donors, while M5AH is the final hydration product of Al2O3 in slag under alkaline conditions and in the presence of sufficient sulfate donors. 13 This is the final hydration product of MgO in slag under alkaline conditions. The final hydration product of Al2O3 is mainly AFt, which promotes the early strength development of cementitious materials.

[0031] In step (4), the main chemical reaction equation is: 2 x SiO2+( y+z+u Al2O3+5 u MgO+(3 x +4 y +3 z Ca(OH)2+3 z CaSO4+(9 y +29 z +13 u H2O→ x CSH+ y C4AH 13 + z AFt+ u M5AH 13 in, x、y、z、u The balancing coefficients in the chemical reaction equations are CSH and C4AH. 13 The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O.

[0032] Based on the above main chemical reaction equations, the optimal molar ratio among the components is determined to be 2:1. x :( y+z+u ): 5 u :(3 x +4 y +3 z ): 3 z .

[0033] In step (5), the contents of each major chemical component in slag, sulfate donor, and alkali activator are shown in Table 1. The optimal mass ratio of slag, sulfate donor, and alkali activator in the all-solid-waste early-strength slag-based cementitious material can be determined. The calculation process is as follows: Table 1 Content

[0034] but: x = a / 12000; u = d / 20000; y + z = b / 10200- d / 20000; Since the hydration product is mainly AFt, we can obtain z = b / 10200- d / 20000.

[0035] Therefore: CaSO4: 3 z =3( b / 10200- d / 20000) mol; Ca(OH)2:3 x +4 y +3 z =3 a / 12000+3( b / 10200- d / 20000) mol.

[0036] Among them, since 1g of slag already containsc / 5600 mol Ca(OH)2 (CaO), then the Ca(OH)2 provided by the alkali activator is [3 a / 12000+3( b / 10200- d / 20000)- c

[5600] mol. Therefore, we can obtain: CaSO4·2H2O: 516 ( b / 10200- d / 20000) g; Ca(OH)2: 222 a / 12000+222( b / 10200- d / 20000) -74 c / 5600 g.

[0037] The mass fraction of CaSO4·2H2O in the sulfate donor is e % The mass fraction of Ca(OH)2 in the alkaline activator is f % Then we can obtain: Sulfate donor: [516( b / 10200- d / 20000)] / e % =(5.06 b -2.58 d ) / e ; Alkali activator:

[222] a / 12000+222( b / 10200- d / 20000)-74 c / 5600] / f % =(1.85 a +2.18 b -1.11 d -1.32 c ) / f。

[0038] In summary: Slag : Sulfate donor : Alkali activator = 1 : (5.06) b -2.58 d ) / e :(1.85 a +2.18 b -1.11 d -1.32 c ) / f = ef:f ( 5.06 b-2.58 d ): e (1.85 a +2.18 b -1.11 d -1.32 c ).

[0039] In step (6), the early strength agent is an alkali metal-based early strength agent, and its dosage is 0.01%-0.07% of the slag mass. The Li in the alkali metal-based early strength agent... + Since plasma does not participate in the hydration reaction and does not change the types of hydration products, it does not change the chemical reaction equation, and the optimal mass ratio of slag, sulfate donor, and alkali activator remains unchanged. eff : f (5.06 b -2.58 d ) : e (1.85 a +2.18 b -1.11 d -1.32 c LiOH·H2O can better promote the early strength development of cementitious materials with high Al phase content, and is suitable for use in slag where the Al2O3 content is higher than the SiO2 content and the seepage prevention requirements are generally low.

[0040] In step (6), when the early-strength agent is a sulfate-based early-strength agent, SO4 in the sulfate-based early-strength agent... 2- It will react with the base activator. In step (4), the main chemical reaction equation is: 4 x SiO2+2( y+z+u Al2O3+10 u MgO+ (6 x+ 8 y+ 6 z+v )Ca(OH)2+(6 zv CaSO4+ v Na2SO4+ (18) y +58 z +26 UV H2O→2 x CSH+2 y C4AH 13 +2 z AFt+2 u M5AH 13 +2 v NaOH in, x、y、z、u、v —Balancing coefficients in chemical reaction equations, CSH is 3CaO2·2SiO2·3H2O, C4AH 13The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O.

[0041] Based on the above main chemical reaction equations, the optimal molar ratio among the components is determined to be 4:1. x :2( y + z + u ): 10 u :(6 x +8 y +6 z + v ):(6 z - v ): v .

[0042] Based on the above equations, and with the components shown in Table 2, the optimal mass ratio of slag, sulfate donor, and alkali activator is derived as follows: Table 2 Content

[0043] but, x = a / 24000; u = d / 40000; v = i / 14200; y + z = b / 20400- d / 40000.

[0044] Since the hydration product is mainly AFt, it can be obtained z = b / 20400- d / 40000.

[0045] Therefore: CaSO4: 6 z - v =6( b / 20400- d / 40000)- i / 14200 mol; Ca(OH)2: 6 x +8 y +6 z + v =6 a / 24000+6(b / 20400- d / 40000)+ i / 14200 mol; Among them, since 1g of slag already contains c / 5600 mol Ca(OH)2 (CaO), then the Ca(OH)2 provided by the alkali activator is [6 a / 24000+6( b / 20400- d / 40000)+ i / 14200- c

[5600] mol. Therefore, we can obtain: CaSO4·2H2O: 1032 ( b / 20400- d / 40000)-172 i / 14200 g; Ca(OH)2: 444 a / 24000+444( b / 20400- d / 40000) +74 i / 14200-74 c / 5600g; The mass fraction of CaSO4·2H2O in the sulfate donor is e % The content (mass fraction) of Ca(OH)2 in the alkali activator is: f % Then we can obtain: Sulfate donor: [1032( b / 20400- d / 40000)-172 i / 14200] / e % =(5.06 b -2.58 d -1.21 i ) / e ; Alkali activator:

[444] a / 24000+444( b / 20400- d / 40000)+74 i / 14200-74 c / 5600] / f % =(1.85 a +2.18 b -1.11 d +0.52 i -1.32 c ) / f ; In summary: Slag : Sulfate donor : Alkali activator = 1 : (5.06) b -2.58 d -1.21 i ) / e :(1.85 a +2.18 b -1.11 d +0.52 i -1.32 c ) / f = eff : f ( 5.06 b -2.58 d -1.21 i ): e (1.85 a +2.18 b -1.11 d +0.52 i -1.32 c ).

[0046] In the formula i This refers to the actual dosage of Na2SO4 early-strength agent, i.e., the mass of slag added. i %. Na2SO4 early strength agent can simultaneously promote the reaction of Al2O3 and SiO2, improve the hardened strength and permeability of cementitious materials, and resist the erosion of corrosive sulfates. It is suitable for use in slag where the Al2O3 content is less than or equal to the SiO2 content and the anti-seepage requirements are high.

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0049] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. These other embodiments are also covered within the scope of protection of this invention.

[0050] Example 1 This embodiment uses S95 grade slag from Hebei Jianshi New Material Technology Co., Ltd., desulfurized gypsum from Huzhou Changxing Powder Materials Co., Ltd., and carbide slag from Nanjing Jinjiali New Material Technology Co., Ltd. as examples. The main components of the slag are SiO2, Al2O3, CaO, and MgO, with contents of 30.73%, 14.36%, 40.39%, and 7.71%, respectively; the main component of the desulfurized gypsum is CaSO4·2H2O, with a content of 93.17%; and the main component of the carbide slag is Ca(OH)2, with a content of 92.68%.

[0051] The chemical reaction equations determined based on the main chemical components of the raw materials and the corresponding final hydration products are as follows: 2 x SiO2+( y+z+u Al2O3+5 u MgO+(3 x +4 y +3 z Ca(OH)2+3 z CaSO4+(9 y +29 z +13 u H2O→ x CSH+ y C4AH 13 + z AFt+ u M5AH 13 Taking 100g of slag as an example, the contents of SiO2, Al2O3, CaO, and MgO in this 100g of slag are 30.73g, 14.36g, 40.39g, and 7.71g, respectively, corresponding to amounts of 0.512mol, 0.141mol, 0.721mol, and 0.193mol. Specifically, 0.512mol of SiO2 requires 0.768mol of CaO (Ca(OH)2) to form CSH, and 0.193mol of MgO requires 0.193mol of MgO to form M5AH. 13 If 0.0386 mol of Al2O3 is needed, then the remaining 0.102 mol of Al2O3 will be used to generate C4AH. 13 And AFt. Because the all-solid waste cementitious material of this invention is characterized by early strength, Al2O3 mainly generates AFt, and C4AH is generated when sulfate donors are insufficient. 13Therefore, the formation of AFt from 0.102 mol Al2O3 requires 0.306 mol CaSO4·2H2O and 0.306 mol Ca(OH)2. In summary, the hydration reaction of 0.512 mol SiO2, 0.141 mol Al2O3, and 0.193 mol MgO requires 1.074 mol Ca(OH)2 and 0.306 mol CaSO4·2H2O.

[0052] 1.074 mol Ca(OH)₂: 100g of slag already provides 0.721 mol CaO (Ca(OH)₂), so only 0.353 mol Ca(OH)₂ needs to be provided by the carbide slag. The mass corresponding to 0.353 mol Ca(OH)₂ is 26.12g. Since the Ca(OH)₂ content in the carbide slag is 92.68%, 28.18g of carbide slag is required.

[0053] 0.306 mol of CaSO4·2H2O: Sulfate ions can only be provided by desulfurized gypsum. The mass corresponding to 0.306 mol of CaSO4·2H2O is 52.63 g. Since the content of CaSO4·2H2O in desulfurized gypsum is 93.17%, 56.49 g of desulfurized gypsum is required.

[0054] In summary, 100g of slag should be mixed with 56.49g of desulfurized gypsum and 28.18g of calcium carbide slag, i.e., slag : desulfurized gypsum : calcium carbide slag = 100 : 56.49 : 28.18 = 93.17 × 92.68 : 92.68 × (5.06 × 14.36 - 2.58 × 7.71) : 93.17 × (1.85 × 30.73 + 2.18 × 14.36 - 1.11 × 7.71 - 1.32 × 40.39) = 8634.996 : 4890.705 : 2448.731 = 100 : 56.64 : 28.36.

[0055] Example 2 The materials used in this embodiment are basically the same as those in Example 1, except that sodium sulfate is used as the early strength agent. This sodium sulfate is produced by Sinopharm Chemical Reagent Co., Ltd., and the amount added is 2% of the slag mass. The formulation is as follows: 4 x SiO2+2( y+z+u Al2O3+10 u MgO+ (6 x+ 8 y+ 6 z+v )Ca(OH)2+(6 zv CaSO4+ v Na2SO4+ (18) y +58 z +26 UV H2O→2 x CSH+2 y C4AH 13 +2 z AFt+2 u M5AH 13 +2 v NaOH Taking 100g of slag as an example, the contents of SiO2, Al2O3, CaO, and MgO in this 100g of slag are 30.73g, 14.36g, 40.39g, and 7.71g, respectively, corresponding to amounts of 0.512mol, 0.141mol, 0.721mol, and 0.193mol. Specifically, 0.512mol of SiO2 requires 0.768mol of CaO (Ca(OH)2) to form CSH, and 0.193mol of MgO requires 0.193mol of MgO to form M5AH. 13 If 0.0386 mol of Al2O3 is needed, then the remaining 0.102 mol of Al2O3 will be used to generate C4AH. 13 And AFt. Because the all-solid waste cementitious material of this invention is characterized by early strength, Al2O3 mainly generates AFt, and C4AH is generated when sulfate donors are insufficient. 13 Therefore, the formation of AFt from 0.102 mol Al2O3 requires 0.306 mol CaSO4·2H2O and 0.306 mol Ca(OH)2. In summary, the hydration reaction of 0.512 mol SiO2, 0.141 mol Al2O3, and 0.193 mol MgO requires 1.074 mol Ca(OH)2 and 0.306 mol CaSO4·2H2O.

[0056] 0.306 mol of CaSO4·2H2O: The addition of Na2SO4 provides SO42-. 2- If 2% of the slag mass contains Na₂SO₄, which is 2g, the corresponding amount of substance is 0.014mol. Therefore, only 0.292mol of CaSO₄·2H₂O needs to be provided by desulfurization gypsum. The mass of 0.292mol of CaSO₄·2H₂O is 50.22g. Since the content of CaSO₄·2H₂O in desulfurization gypsum is 93.17%, 53.91g of desulfurization gypsum is required.

[0057] 1.074 mol Ca(OH)2: 100 g of slag already provides 0.721 mol CaO (Ca(OH)2), but Na2SO4 will consume OH... -Therefore, 0.014 mol of Na₂SO₄ requires 0.014 mol of Ca(OH)₂. In summary, 0.367 mol of Ca(OH)₂ needs to be provided by carbide slag. The mass of 0.367 mol of Ca(OH)₂ is 27.16 g. Since the Ca(OH)₂ content in carbide slag is 92.68%, 29.30 g of carbide slag is required.

[0058] In summary, 100g of slag should be mixed with 53.91g of desulfurized gypsum and 29.30g of calcium carbide slag, i.e., slag : desulfurized gypsum : calcium carbide slag = 100 : 53.91 : 29.30 = 93.17×92.68 : 92.68×(5.06×14.36-2.58×7.71-1.21×2) : 93.17×(1.85×30.73+2.18×14.36-1.11×7.71+0.52×2-1.32×40.39) = 8634.996 : 4666.419 : 2545.628 = 100 : 54.04 : 29.48.

[0059] Example 3 like Figure 2 As shown, this embodiment provides a production system for early-strength slag-based cementitious materials made entirely from solid waste, including an XRF online detection element, an intelligent proportioning calculation and control center, a raw material fine pretreatment and conveying unit, and a high-uniformity mixing unit. All components in this production system are existing models.

[0060] The XRF online detection element integrates a high-power miniature X-ray tube, an ultra-large area silicon drift detector, and a dedicated vacuum / helium purger, overcoming the challenge of signal attenuation and accurate measurement difficulties caused by light elements such as silicon, aluminum, calcium, and sulfur in air. The XRF online detection element incorporates an advanced fundamental parameter (FP) algorithm and an adaptive matrix compensation model to overcome the challenge of analyzing the mutual influence of light elements in the slag matrix. The FP fundamental parameter method is used to analyze and process experimental data and is suitable for complex systems involving multiple variables and parameters. Adaptive matrix compensation is a fault-tolerant control method in information science for actuator failures in multi-input multi-output (MIMO) nonlinear systems. It achieves reference model tracking through the design of adaptive control laws, simultaneously handling system uncertainties and actuator failures without relying on a fault diagnosis unit.

[0061] The intelligent proportioning calculation and control center is used to realize the proportioning design method of solid waste slag-based cementitious materials. It can receive real-time raw material chemical composition data from the XRF online detection element in the raw material silo, automatically calculate the optimal mass proportion of the current batch of raw materials, and determine the required early strength agent type based on the real-time mass ratio of Al2O3 to SiO2 in the slag. Then, it generates control commands to precisely regulate the feeding rate of each raw material conveying unit and the feeding amount of the metering scale.

[0062] The raw material fine pretreatment and conveying unit mainly includes a slag powder grinding device, a raw material silo, and a closed screw conveyor. The slag powder grinding device adopts a closed-loop system of a vertical roller mill and a high-efficiency air classifier, and grinds the slag to a specific surface area of ​​not less than 450 m² by adjusting the roller pressure and air speed. 2 / kg, to fully activate its potential gelling activity; the raw material bins are slag bins, sulfate donor bins, alkali activator bins, and early strength agent bins, all of which are equipped with XRF online detection elements; the closed screw conveyor can receive control commands from the intelligent proportioning calculation and control center, and adjust the motor frequency of the precision star feeder and metering screw scale under each raw material bin in real time through the PID controller, and send it into the mixing bin through the fully enclosed tubular chain conveyor, so as to realize the feeding feedback regulation and eliminate secondary pollution of raw materials during transportation.

[0063] The high uniformity mixing unit is a twin-shaft paddle-type zero-gravity mixer. Its mixing speed and time are dynamically adjusted according to the fineness and moisture content of the raw materials to be mixed. The specific control formula is as follows to ensure that the components are mixed evenly. N = k 1×( SSA ) -1 / 2 ×(1+ ω ) -1 / 3 t = k 2×( SSA ) ×(1+ ω ) In the formula: N It refers to the optimized speed of the mixer, in RPM; t SSA is the optimized mixing time, in seconds; SSA is the specific surface area of ​​the slag, in meters. 2 / kg represents fineness; ω It is the mass-weighted average moisture content of all materials in the mixed system, expressed as % / 100, i.e., in decimal form. For example, if the moisture content is 2%, then... ω =0.02; k 1, k 2 is a system-specific empirical coefficient that needs to be determined through equipment calibration.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and does not limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing the component proportions of a solid waste slag-based cementitious material, characterized in that, Includes the following steps: (1) The components of the solid waste early-strength slag-based cementitious material are classified according to slag, sulfate donor, alkali activator and early-strength agent; (2) XRF spectroscopy was used to determine the types and mass contents of the main chemical oxides in the slag, sulfate donor, and alkali activator; (3) Determine the target hydration products of the cementitious material system based on the main chemical components in the slag, sulfate donor, and alkali activator; (4) Based on the target hydration products and the main chemical components in slag, sulfate donor and alkali activator, derive the main chemical reaction equations of the system and determine the optimal molar ratio between the main chemical components required to achieve the reaction; (5) Based on the content of each raw material component measured in step (2), the optimal molar ratio relationship described in step (4) is converted into the optimal mass ratio between slag, sulfate donor and alkali activator. (6) Add different types of early strength agents to the basic mix proportion obtained in step (5) to obtain a solid waste early strength slag-based cementitious material suitable for different engineering requirements.

2. The method for designing the composition ratio of a solid waste slag-based cementitious material according to claim 1, characterized in that, In step (1), the slag is blast furnace slag, and its main chemical components are SiO2, Al2O3, CaO and MgO; The sulfate donor is a solid waste material containing sulfate ions, which is one or a mixture of desulfurized gypsum, desulfurized ash, phosphogypsum, and fluorogypsum, and its main chemical component is CaSO4·2H2O. The alkaline activator is a calcium-containing alkaline solid waste material, and its main chemical component is Ca(OH)2.

3. The method for designing the composition ratio of a solid waste slag-based cementitious material according to claim 1, characterized in that, In step (2), the mass fractions of SiO2, Al2O3, CaO, and MgO in the slag are respectively a % , b % , c % and d % The mass fraction of CaSO4·2H2O in the sulfate donor is: e % The mass fraction of Ca(OH)2 in the alkaline activator is f % .

4. The method for designing the component proportions of a solid waste slag-based cementitious material according to claim 1, characterized in that, The target hydration products in step (3) are 3CaO·2SiO2·3H2O, 4CaO·Al2O3·13H2O, 3CaO·Al2O3·3CaSO4·32H2O, and 5MgO·Al2O3·13H2O.

5. The method for designing the composition ratio of a solid waste slag-based cementitious material according to claim 1, characterized in that, In step (4), the main chemical reaction equation is: 2 x SiO2+( y+z+u )Al2O3+5 u MgO+(3 x +4 y +3 z )Ca(OH)2+3 z CaSO4+(9 y +29 z +13 u )H2O→ x CSH+ y C4AH 13 + z AFt+ u M5AH 13 in, x, y, z, u The balancing coefficients in the chemical reaction equations are CSH and C4AH. 13 The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O; The optimal molar ratio among SiO2, Al2O3, MgO, Ca(OH)2, and CaSO4 is 2. x :( y+z+u ): 5 u :(3 x +4 y +3 z ): 3 z .

6. The method for designing the component proportions of a solid waste slag-based cementitious material according to claim 5, characterized in that, Step (5) includes the following steps: S1. Establish calculation benchmark: Use 1g of slag as the benchmark unit for calculation; S2, Molar conversion: Based on the content of each raw material component in step (2), calculate the number of moles of each reactant that 1g of slag can provide; S3. Set targets for hydration products; S4. Calculate the external raw material requirements: Based on the optimal molar ratio in step (4), calculate the molar amounts of calcium sulfate and calcium hydroxide required to completely react with 1 gram of slag components. S5. Deduct the portion of slag self-supply: Since slag itself contains CaO, this portion needs to be subtracted from the total demand to obtain the net demand for Ca(OH)2 that must be provided by an external alkali activator. S6. Mass Conversion and Raw Material Conversion: Convert the required quantity of pure chemical substances into mass, and then perform the final conversion based on the purity of the actual raw materials. S7. Obtain the final mass ratio: After the above steps, the mass of sulfate donor and alkali activator precisely matched to 1 gram of slag is obtained, and the optimal mass ratio calculation formula is derived: Slag : Sulfate donor : Alkali activator = ef : f ( 5.06 b -2.58 d ): e (1.85 a +2.18 b -1.11 d -1.32 c ).

7. The method for designing the composition ratio of a solid waste slag-based cementitious material according to claim 1, characterized in that, In step (6), the early strength agent is an alkali metal early strength agent, and its dosage is 0.01%-0.07% of the slag mass.

8. The method for designing the composition ratio of a solid waste slag-based cementitious material according to claim 1, characterized in that, In step (6), the early-strength agent is a sulfate-based early-strength agent. In step (4), the main chemical reaction equation is: 4 x SiO2+2( y+z+u )Al2O3+10 u MgO+(6 x+ 8 y+ 6 z+v )Ca(OH)2+(6 zv )CaSO4+ v Na2SO4+(18 y +58 z +26 UV )H2O→2 x CSH+2 y C4AH 13 +2 z AFt+2 u M5AH 13 +2 v NaOH in, x, y, z, u, v —Balancing coefficients in chemical reaction equations, CSH is 3CaO2·2SiO2·3H2O, C4AH 13 The value is 4CaO·Al₂O₃·13H₂O, AFt is 3CaO·Al₂O₃·3CaSO₄·32H₂O, M₅AH 13 It is 5MgO·Al2O3·13H2O; The optimal molar ratio among SiO2, Al2O3, MgO, Ca(OH)2, CaSO4, and Na2SO4 is 4. x :2( y + z + u ): 10 u :(6 x +8 y +6 z + v ):(6 z - v ): v .

9. The method for designing the component proportions of a solid waste slag-based cementitious material according to claim 8, characterized in that, In step (5), the actual dosage of the sulfate-based early-strength agent is [amount]% of the slag mass. i The optimal mass mix ratio is calculated as: slag : sulfate donor : alkali activator = ef : f ( 5.06 b -2.58 d -1.21 i ): e (1.85 a +2.18 b -1.11 d +0.52 i -1.32 c ).

10. A production system for all-solid waste slag-based cementitious materials, comprising an XRF online detection element, an intelligent proportioning calculation and control center, a raw material fine pretreatment and conveying unit, and a high-uniformity mixing unit, characterized in that, The intelligent proportioning calculation and control center is used to implement the composition proportioning design method of the all-solid waste slag-based cementitious material as described in any one of claims 1-9. It receives real-time raw material chemical composition data fed back from the XRF online detection element of the raw material silo, automatically calculates the optimal mass proportion of the current batch of raw materials, and determines the required early strength agent type based on the real-time mass ratio of Al2O3 to SiO2 in the slag. It generates control commands to regulate the feeding rate of each raw material conveying unit and the feeding amount of the metering scale. The high-uniformity mixing unit is a twin-shaft paddle-type zero-gravity mixer. Its mixing speed and time are dynamically adjusted according to the fineness and moisture content of the raw materials to be mixed. The specific control formula is as follows: N = k 1×( SSA ) -1 / 2 ×(1+ ω ) -1 / 3 t = k 2 ×( SSA ) ×(1+ ω ) In the formula: N Optimized speed for the mixer, RPM; t For optimized mixing time, s; SSA is the specific surface area of ​​slag, in m². 2 / kg; ω The mass-weighted average moisture content of all materials in the system, % / 100; k 1, k 2 is an empirical coefficient.

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