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CN-122024875-A - Quantitative evaluation method for reactive components and in-situ reaction degree of precursor in alkali excitation reaction

CN122024875ACN 122024875 ACN122024875 ACN 122024875ACN-122024875-A

Abstract

The invention discloses a quantitative evaluation method for the reactive components and in-situ reaction degree of a precursor in an alkali excitation reaction, which aims to solve the problem that the conventional reactive components and in-situ reaction degree of the precursor are difficult to accurately test and quantify. The quantitative evaluation method comprises the steps of firstly, ① calculating the total content of the reactive components through a theoretical prediction model, ② calculating the content of the reactive components through an alkali solution dissolution test, ③ calculating the result, secondly, evaluating the in-situ reaction degree to obtain the in-situ reaction degree RD 0 , and thirdly, calculating each reactive component participating in the reaction in the precursor through the in-situ reaction degree. The idealized assumption that the total oxide content or amorphous phase content of the precursor is simply equal to the reactable components is avoided, the reaction behavior of the precursor under the real alkali excitation condition is reflected, the accurate quantification of the effective components of the precursor under the in-situ reaction condition is realized, and a reliable basis is provided for the cooperative utilization of the multi-source industrial solid waste precursor and the accurate proportioning design of the alkali excitation material.

Inventors

  • YE WANLI
  • TAN YIQIU

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. The quantitative evaluation method for the degree of the in-situ reaction of the reactive components of the precursor in the alkali excitation reaction is characterized by comprising the following steps: Step one, evaluation of the reactive components: ① Calculating the total content of the reactive components by a theoretical prediction model: a. grinding the precursor to obtain a ground precursor; b. Carrying out chemical analysis on the grinded precursor to respectively obtain total t-CaO of equivalent oxides CaO, total t-SiO 2 of SiO 2 and total t-Al 2 O 3 of Al 2 O 3 ; c. Quantitatively analyzing the ground precursor, dissolving the precursor in an alkaline solution at normal temperature to obtain the amorphous phase content amor-CaO, the active crystalline phase content crya-CaO and the inert crystalline phase content cryi-CaO of oxide CaO, the amorphous phase content amor-SiO 2 , the active crystalline phase content crya-SiO 2 and the inert crystalline phase content cryi-SiO 2 of oxide SiO 2 , the amorphous phase content amor-Al 2 O 3 , the active crystalline phase content crya-Al 2 O 3 and the inert crystalline phase content cryi-Al 2 O 3 of oxide Al 2 O 3 by taking the dissolved crystalline phase as an active crystalline phase and taking the insoluble crystalline phase as an inert crystalline phase; d. calculating according to the steps (9) - (11) to obtain the content of each reactive component in the precursor of the theoretical model method: (9) (10) (11) Wherein the method comprises the steps of Represents the content of the components capable of reacting CaO in the precursor by a theoretical model method, Represents the content of the components of the reactive SiO 2 in the precursor by a theoretical model method, Representing the content of a reactive Al 2 O 3 component in a precursor by a theoretical model method; ② The content of the reactive components is calculated by alkali lye dissolution test: e. Adding a precursor with initial mass of m 0 into NaOH solution, preparing to obtain suspension, stirring, performing solid-liquid separation to obtain supernatant and residual solid phase, repeatedly adding the NaOH solution into the residual solid phase, performing solid-liquid separation until the mass of the residual solid phase is constant, and performing test calculation to obtain the mass fraction w Ca of the reactable CaO component, the mass fraction w Si of the reactable SiO 2 component and the mass fraction w Al of the reactable Al 2 O 3 component in the supernatant; f. adding the residual solid phase into pure water for ultrasonic cleaning, and separating to obtain a cleaned residual solid phase; g. drying the cleaned residual solid phase to constant weight, wherein the mass of the precursor dissolved in the NaOH solution part is delta m, and the total content test value of the reactive components of the precursor is RP A ; and then calculating the content of each reactive component in the precursor of the dissolution test method according to formulas (14) - (16): (14) (15) (16) In the middle of -The content of the reactable CaO component in the precursor of the dissolution test method; -the content of the reactive SiO 2 component in the dissolution test precursor; -the content of the reactive Al 2 O 3 component in the dissolution test precursor; ③ Result calculation Taking the content of each reactive component in the precursor by a theoretical model method, the content of each reactive component in the precursor by a dissolution test method or the average value of the two as the content of the reactive components of the precursor, namely the content of a-CaO in the precursor, namely the content of a-SiO 2 in the precursor, the content of a-SiO 2 in the precursor and the content of a-Al 2 O 3 in the precursor, namely the content of a-Al 2 O 3 in the precursor; Step two, in-situ reaction degree evaluation: ① Under an application scene, mixing a precursor and an alkaline solution to construct an alkali excitation reaction system, and calculating to obtain an in-situ reaction degree RD 0 under the reaction system through formulas (1), (2) and (3); (1) (2) (3) RD 0 -degree of in situ reaction; -the ideal degree of reaction; α (T) -reduction factor; t-reaction temperature; D 50 —precursor median particle diameter μm; C Na —alkali content wt.% in the reaction system, i.e. Na 2 O/（Na 2 O+H 2 O); t f -reaction time d; ② Mixing a precursor and an alkaline solution to construct an alkali excitation reaction system, and constructing a relation curve of the reaction degree RD-reaction thickness delta according to formulas (4) - (5) based on the particle size distribution condition of the precursor, so as to determine the in-situ reaction degree RD 0 under the alkali excitation reaction system by utilizing the in-situ reaction thickness delta 0 ; (4) (5) RD-extent of reaction in the formula; RD d -extent of reaction of precursor particles of diameter d μm; p d -the proportion of precursor particles having a diameter d μm; m DRP ,m RP -the total mass of the reactive components involved in the reaction and the total mass kg of the reactive components, respectively; V DRP ,V RP -the total volume of the reactive components involved in the reaction and the total volume of the reactive components m 3 , respectively; d-particle diameter μm; d, the maximum value of particle diameter is mu m; Delta-reaction thickness μm; Step three, effective component evaluation: in-situ reaction degree RD 0 of the precursor is determined by step ① or step ② of the second step under the alkali excitation reaction system, and each reactive component participating in the reaction in the precursor is obtained and calculated according to the following formulas (17) - (19): (17) (18) (19) Wherein a-CaO diss is a reactive CaO component participating in the reaction in the precursor; a-SiO 2 diss -a reactive SiO 2 component in the precursor which participates in the reaction; a-Al 2 O 3 diss -a reactive Al 2 O 3 component in the precursor that participates in the reaction; thus completing the quantitative evaluation method of the reactive components and the in-situ reaction degree of the precursor in the alkali excitation reaction.
  2. 2. The method for quantitatively evaluating the degree of in-situ reaction of the reactive components of the precursor in the alkali-activated reaction according to claim 1, wherein the precursor is one or more of fly ash, slag, red mud, steel slag and biomass ash.
  3. 3. The method for quantitatively evaluating the degree of in-situ reaction of a reactive component of a precursor in an alkali-activated reaction according to claim 1, wherein the precursor is milled to <10 μm in step a.
  4. 4. The method for quantitatively evaluating the degree of in-situ reaction of a reactive component of a precursor in an alkali-activated reaction according to claim 1, wherein the milled precursor is subjected to X-ray fluorescence spectroscopy in step b.
  5. 5. The method for quantitatively evaluating the degree of in-situ reaction of a reactive component of a precursor in an alkali-activated reaction according to claim 1, wherein the precursor is quantitatively analyzed by an X-ray diffractometer in step c.
  6. 6. The method for quantitatively evaluating the degree of in-situ reaction between the reactive components of the precursor in the alkali-activated reaction according to claim 1, wherein the calculation formula of the predicted value RP T of the total content of the reactive components of the precursor in the step d is as follows: 。
  7. 7. The method for quantitatively evaluating the extent of the in-situ reaction of a reactive component of a precursor in an alkali-activated reaction according to claim 1, wherein the molar concentration of the NaOH solution in step e is 12mol/L.
  8. 8. The method for quantitatively evaluating the degree of in-situ reaction and the reactive components of a precursor in an alkali-activated reaction according to claim 1, wherein in the step e, an inductively coupled plasma emission spectrometer or an inductively coupled plasma mass spectrometry is used to test the mass fraction w Ca of the reactive CaO in the supernatant, the mass fraction w Si of the reactive SiO 2 and the mass fraction w Al of the reactive Al 2 O 3 .
  9. 9. The method for quantitatively evaluating the degree of in-situ reaction of a reactive component of a precursor in an alkali-activated reaction according to claim 1, wherein the drying temperature in step g is 250 ℃.
  10. 10. The method for quantitatively evaluating the degree of in-situ reaction and the reactive components of a precursor in an alkali-activated reaction according to claim 1, wherein the step three is to divide the reactive components in the precursor into reactive components a-CaO diss 、a-SiO 2 diss and a-Al 2 O 3 diss participating in the reaction and reactive components a-CaO und 、a-SiO 2 und and a-Al 2 O 3 und not participating in the reaction.

Description

Quantitative evaluation method for reactive components and in-situ reaction degree of precursor in alkali excitation reaction Technical Field The invention belongs to the technical field of alkali-activated materials, and particularly relates to a quantitative evaluation method for the degree of a reaction in situ and a reactive component of a precursor in alkali-activated reaction. Background In the existing alkali-activated material system, various industrial solid wastes such as fly ash, slag, red mud, steel slag, biomass ash and the like are widely used as precursors. These materials generally have the characteristics of complex composition, multiphase structure, obvious activity difference and the like. The prior art generally relies on chemical component analysis (e.g., XRF) to obtain the elements as a quantification as "total chemical composition" or mineral composition analysis (e.g., XRD, microscopic observation) to obtain "mineral phase composition" for guiding the proportioning design. However, such methods cannot accurately characterize the "reactive components" of the precursor having reaction potential under the alkali excitation condition, and neglect the in-situ reaction degree of these reactive components, so that the "reactive components participating in reaction" which actually dissolve, rearrange and participate in gel formation cannot be accurately quantified, and it is difficult to provide a direct basis for the design of the refined proportioning of the alkali excitation material. Another common method is to evaluate the precursor activity indirectly according to mechanical properties or gelation properties, for example, by means of compressive strength development, activity index, standard mortar trial, etc., and compare precursors from different materials or under different process conditions. The posterior method has long experimental period and large workload, is seriously dependent on the specific proportion of a gel system, maintenance conditions and test piece preparation process, and the test result is often influenced by multiple factors, so that the instruction of the result on the proportion design of the alkali-activated material is limited. Therefore, a quantitative evaluation method for the types and the contents of the reactive components participating in the reaction in the precursor is not available at present, so that the proportion design of the alkali-activated material depends on experience, and the comprehensive utilization of the multi-source solid waste precursor is difficult to realize. Disclosure of Invention The invention aims to solve the problem that the existing precursor reactive components and in-situ reaction degree are difficult to accurately test and quantify, and provides a quantitative evaluation method for the precursor reactive components and in-situ reaction degree in alkali excitation reaction. The quantitative evaluation method of the reactive components and the in-situ reaction degree of the precursor in the alkali excitation reaction is realized according to the following steps: Step one, evaluation of the reactive components: ① Calculating the total content of the reactive components by a theoretical prediction model: a. grinding the precursor to obtain a ground precursor; b. Subjecting the ground precursor to chemical analysis to obtain the total amount t-CaO (wt.%), the total amount t-SiO 2 (wt.%) of SiO 2 and the total amount t-Al 2O3 (wt.%) of Al 2O3 of equivalent oxide CaO respectively; c. Quantitatively analyzing the ground precursor, dissolving the precursor in an alkaline solution at normal temperature to obtain an amorphous phase content amor-CaO (wt.%), an active phase content crya-CaO (wt.%) and an inert phase content cryi-CaO (wt.%), an amorphous phase content amor-SiO 2 (wt.%), an active phase content crya-SiO 2 (wt.%) and an inert phase content cryi-SiO 2 (wt.%), an amorphous phase content amor-Al 2O3 (wt.%), an active phase content crya-Al 2O3 (wt.%) and an inert phase content cryi-Al 2O3 (wt.%) of oxide Al 2O3 respectively by taking the dissolved crystalline phase as an active crystalline phase and an insoluble crystalline phase as inert crystalline phases; d. calculating according to the steps (9) - (11) to obtain the content of each reactive component in the precursor of the theoretical model method: (9) (10) (11) Wherein the method comprises the steps of Representing the content (wt.%) of the reactive CaO component in the precursor by the theoretical modeling method,Representing the content (wt.%) of the reactive SiO 2 component in the precursor by the theoretical model method,Representing the content (wt.%) of a reactive Al 2O3 component in the precursor of the theoretical model method; ② The content of the reactive components is calculated by alkali lye dissolution test: e. Adding a precursor with initial mass of m 0 into NaOH solution, preparing to obtain suspension, carrying out solid-liquid separation after stirring