Transforming Zeolite Tuff and Cigarette Waste into Eco-Friendly Ceramic Bricks for Sustainable Construction

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

After a major revision, the text began to look better, the authors did quite a lot of work. The work may be published

Author Response

Thank you for considering our revised version and for your efforts. 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The reviewer acknowledges the authors' dedication to material characterization and data analysis; however, it appears imperative for the authors to prioritize meticulousness in data acquisition and analysis. From the reviewer's standpoint, the data analysis presented in this manuscript falls short of meeting the expected standards within the discipline. Consequently, regrettably, the reviewer finds it necessary to decline publication of this manuscript in Buildings.

Lines 65-72: The reviewer contends that the extensive listing of literature is irrelevant and unnecessary. The authors have previously expounded upon the characteristics of cigarette waste and its utilization in brickmaking. Enumerating a multitude of other waste materials incompatible with the utilized raw material in this manuscript appears illogical.

Lines 124-126: According to the reviewer's perspective, milling for a duration of 15 minutes appears improper, potentially resulting in the reduction of all particles to micro-scale dimensions. Practical brickmaking clay mixes typically comprise a combination of millimeter-sized and micro-sized particles. A substantiated argument or declaration is requested.

Lines 171-174: The XRD-based phase identification methodology employed in this study is deemed inadequate. Firstly, the confirmation of montmorillonite solely based on powder XRD lacks substantiation; examination of air-dried and glycol-treated clay slides is imperative. Furthermore, the sharp reflection at ~15 appears unlikely to be associated with montmorillonite. Secondly, although cristobalite is indicated, the principal reflection of this phase, demonstrating an interlayer distance of ~4.04 Angstrom, has not been delineated in Fig.2. Thirdly, discerning between illite and mica solely through XRD search/match is exceedingly challenging; therefore, the reference to illite in the manuscript should be revised to encompass illite/mica.

Table 2: The oxide composition and phase content of zeolite tuff, as obtained from XRD and XRF analyses, prompt doubts from the reviewer regarding the authenticity of XRF analysis on the zeolite tuff. The assertion that XRF can accurately delineate the chemical compositions of individual phases, along with the total weight percentage of each element in the zeolite tuff precisely equating to the sum of corresponding elements in individual phases, raises skepticism. The methodology employed by the authors to achieve this remains undisclosed, including the process for obtaining quantitative phase analysis results.

Author Response

Thank you for considering our revised version and for your efforts. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript deals with a relevant and topical issue such as the development of new building materials with the incorporation of wastes that are currently an environmental problem. In general, the paper is well structured although some sections need to be expanded/improved as detailed below. The document lacks references to support the observed results and the results need to be discussed in a systematic and clear way.

Incorporate in the introduction final results achieved by other research where raw materials used separately in the manufacture of building materials have been incorporated.

The methodology needs to be thoroughly expanded:

Line 123: Specify equipment and methodology used for primary milling of the waste. What total amount of material was milled to obtain the test specimens?

Table 1: Specify in the table that the numbers refer to percentages. Also indicate in the text how it could be ensured that each of the test specimens contains the indicated amount of residue since the % of cigarette residue is very low.

Line 127: Specify that the moulds were cylindrical with the indicated dimensions.

Line 128: Specify how the pressure of 55 MPa was exerted on the specimens (equipment, methodology).

Include photographs of the raw material used.

Line 129: Indicate whether the specimens were introduced into the electric kiln after demoulding or not.

Explain in more detail and more clearly the process of obtaining the specimens (are there any series of specimens without heat treatment, how many specimens were produced for each of the temperatures, were the specimens introduced at room temperature...).

Figure 1: Heating rate does not match what is stated in the text.

Line 147: Explain the equipment and method used to perform the XRF analysis.

Line 162: indicate the speed of application of the press force.

Line 170: XRD and XRF analysis should appear in the title.

Line 183-186: This sentence is not related to the paragraph.

Sections 3.1.1. and 3.1.2. simply describe the test results. Include some discussion.

Place section 3.1.2. after 3.1.3., and specify in Figure 5 where the EDS analyses have been carried out, especially in the case of tobacco as it is a more heterogeneous material.

Section 3.1.5. Thermal properties of initial raw materials: Revise this section completely as many of the values described in the text do not coincide with Figure 7. Include in this section as part of the discussion, the relationship between the ATG results and the temperatures reached during the thermal treatment.

Line 230: The first mass variation is up to approx. 300°C according to Fig. 7, not 200°C.

Line 236: Specify whether the observed endothermic peak leads to any loss of mass or not.

Line 239-240: Place at the beginning of the paragraph.

Line 246: Mass loss does not coincide with figure 7.

Line 248: Peak temperature does not agree with figure 7.

Line 249: Mass loss does not agree with figure 7.

Line 251: does not agree with figure 7.

Figure 7: The indicated values are not well understood, use another graph to indicate the mass loss.

Line 265: How is noticeable volume shrinkage demonstrated (tests, measurement methods...)?

Line 267-268: Relate to the elementary analyses made at the beginning.

Line 283-287: Incorporate reference to justify the statement.

Line 277: Incorporate the analysis of the rest of the dosages.

Figure 9: The blue line refers to the compound without heat? specify because it seems to refer to the raw material.

Figure 10: The compound ZCW12 is missing. Incorporate images of the unheated composites to make a comparison of the internal processes that the material undergoes.

Incorporate in section 3.2.3. SEM identification of the fired ceramic bricks, a discussion on the influence of increased cigarette residue.

Line 298: Incorporate reference to justify the statement.

Line 314: density values do not match Figure 11

Figure 11: Are there any series without fired temperatures? Add

Line 320: Inconsistent with SEM results, where it was indicated that density was reduced.

Line 330: Incorporate reference that justifies the statement.

Line 333: Which compound is considered a reference.

Line 341: Inconsistent with what is stated in the SEM section.

349-352: Incorporate reference to justify the statement.

In all figures the values must have the same number of decimal places.

Line 359-361: Incorporate reference to justify the statement.

Line 355 states: "the inclusion of 12% cigarette waste results in increased shrinkage, ranging from 13.1% to 30.9%", and in line 361 "Samples containing cigarette waste exhibit reduced shrinkage". The final conclusion of the inclusion of cigarette waste should be consistent with the results.

Line 409: Only the composite with 12% cigarette waste and temperature 950 does not reach 7 MPa (does not match the values in the figure).

Line 420: Only one of the compounds is referenced at a specific temperature, what about the other temperatures? The results of the different compounds do not compare well, it is not ordered or clear.

Line 424: what aspect do other studies refer to, develop.

Future lines of work and limitations of the study are missing.

A large number of self-references have been detected, so it is requested that each of them be adequately justified.

Author Response

Thank you for considering our revised version and for your efforts. 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors may lack expertise in mineralogy; however, in Fig. 2:

11)      Replace "Illite" with "Illite/Mica" as distinguishing between illite and mica via XRD alone is impractical. To confirm, one can use PDF cards of muscovite or biotite to match the XRD pattern of the sample.

22)      Consider replacing "Montmorillonite" with "Smectite" for similar reasons, depending on the authors' discretion.

Regarding Table 2, clarification is required on how the chemical composition, determined by XRF, precisely aligns with quantitative phase analysis (QPA) using Rietveld refinement in conjunction with the chemical formula of various phases. Key queries include:

11)      Montmorillonite (PDF 00-003-0010) does not have its .cif file in the ICDD; how do the authors run Rietveld refinement without this file?

22)      Requested is a refinement result showing the comparison between the simulated and collected XRD patterns.

33)      There must be a certain amount of amorphous phase in ZT that can not be detected by XRD. Since the authors didn’t use an internal standard during the Rietveld refinement, this part cannot be demonstrated. However, the XRF data reflects both crystal phase and amorphous phases. In this regard, why the chemical composition by XRF can exactly match the QPA through Rietveld refinement combined with the chemical formula? It makes no sense. In addition, even if the amorphous phase is considered, the Rietveld refinement has limited accuracy, so the chemical compositions by XRF and QPA + chemical formula of different phases should present some degree of inconsistency. Furthermore, please note that the chemical formula in the PDF card may be ideal but not equal to the actual ones in ZT.

Lines 236-250: To reinforce the interpretation of ZT's TGA-DTA data, the inclusion of pertinent references such as https://doi.org/10.1016/j.clay.2019.105419 and https://doi.org/10.1016/j.jobe.2022.105802 is recommended.

Regarding Fig. 9, the alteration in fired bricks' color at different temperatures prompts a query that necessitates clarification from the authors.

Lines 325-326 “The decrease in density observed in the bricks containing cigarette waste can be assigned to the higher porosity observed in these samples”

The reduced density is attributable not only to increased porosity but also to the heightened volume shrinkage of the brick body following waste addition (refer to Figure 14). Amend the description accordingly.

Author Response

We appreciate the time and effort that you have dedicated to providing your valuable feedback on our manuscript. We are very grateful to you for your careful review and constructive suggestions

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have made all the changes proposed by the reviewer. The article has been significantly improved and is suitable for publication in the journal.

Author Response

We appreciate the time and effort that you have dedicated to providing your valuable feedback on our manuscript. We are very grateful to you for your careful review and constructive suggestions