Managing Marble Quarry Waste: Opportunities and Challenges for Circular Economy Implementation

Round 1

Reviewer 1 Report

REVIEW

1.I don't think the title is right for this paper, so the following suggestions are made:

·         “Sustainable Solutions for Marble Quarry Waste: Opportunities for Circular Economy Integration”

·         "Maximizing Resource Efficiency: Circular Economy Strategies for Marble Quarry Fine Particle Recovery"

·         "Managing Marble Quarry Waste: Opportunities and Challenges for Circular Economy Implementation"

2.It is considered that the abstract should have a few minor changes

·         I replaced "is the largest" with "has been a prominent" to provide a more dynamic and varied description of the marble.

·         I changed "used commonly" to "commonly employed" to improve language fluency.

·         Modifiqué "represent one of the environmental problems affecting dimension stone industry" a "poses significant environmental challenges for the dimension stone industry" para una expresión más clara y concisa.

·         I replaced "In most cases" with "The difficulty" to maintain consistency and clarity in context.

·         Cambié "where more than half of the exploited marbles still result in quarry waste or debris" a "where more than half of the extracted marble remains as quarry waste or debris" para una expresión más precisa y directa.

·         I changed "generate greater amounts" to "have intensified the production" for a more active and accurate description of the situation.

·         I changed "often landfilled as waste or abandoned" to "commonly through landfilling or abandonment" to improve language fluency and sentence structure.

·         Reemplacé "The primary purpose of this research was" con "This research primarily aimed to" para una redacción más clara y directa.

·         I changed "has provided valuable insights" to "reveal" for a more active and dynamic expression.

·         Modifiqué "These characteristics could be favorable for a possible reuse" a "suggesting potential for reuse" para una expresión más clara y concisa del hallazgo.

These changes were made to improve the clarity, accuracy, and fluidity of the abstract.

Here are suggested changes to the abstract:

Marble has been a prominent natural stone utilized since ancient times, commonly employed in construction and as an ornamental stone. However, the disposal of waste generated from marble extraction, particularly fine sludge, poses significant environmental challenges for the dimension stone industry. The difficulty in managing and recovering these materials, exacerbated by local regulations and the absence of suitable recovery protocols, often leads to landfilling. This issue is exemplified by the Carrara marble basin in the Apuan Alps (Tuscany, Italy), where more than half of the extracted marble remains as quarry waste or debris.

Modern cutting techniques have intensified the production of finer materials and sawing residue, known as "marmettola," ranging in size from fine sand to silt. Disposal of these materials, commonly through landfilling or abandonment, has profound environmental repercussions. This research primarily aimed to conduct a preliminary physical, mineralogical, and morphological characterization of the fine waste and sludge generated from Carrara Marble exploitation. The findings reveal high granulometric uniformity and nearly pure carbonate composition, suggesting potential for reuse in various industrial sectors such as paper, plastics, and pharmaceuticals.

3.    Introduction

Here are recommendations for the introduction:

·         Start by emphasizing the economic significance and historical importance of the dimension stones industry, highlighting its role in construction, art, and cultural heritage preservation.

·         Provide updated statistics or trends to illustrate the industry's growth and global impact, referring to recent publications or reports.

·         Discuss the challenges associated with dimension stone production, particularly the generation of significant waste, and highlight its environmental implications.

·         Outline the phases of dimension stone production, from exploration to quarrying and processing, emphasizing the substantial amount of waste generated at each stage.

·         Include statistics or data on the proportion of waste generated relative to the total extracted material, providing context for the scale of the issue.

·         Introduce the concept of extractive waste (EW) and its potential for recovery and reuse in various applications, showcasing the importance of sustainable management practices.

·         Mention specific potential applications for recovered dimension stone waste, such as aggregate production, industrial minerals, environmental rehabilitation, and raw material substitution.

·         Conclude the introduction by highlighting the importance of addressing dimension stone waste management for both environmental sustainability and resource efficiency.

By incorporating these recommendations, the introduction will provide a comprehensive overview of the dimension stones industry, its challenges, and the potential for sustainable solutions.

4.    Remove red text from line 109

5.    Line 104-114 Here are the changes made to the text:

2. The Carrara Marble Basin

2.1 Geological and Historical Setting

Situated in the northernmost reaches of Tuscany, Italy, the Carrara Marble Basin (CMB) is nestled within the picturesque Apuan Alps region and stands as one of the preeminent marble quarrying districts globally. Spanning approximately 375 square kilometers, this basin is intricately divided into four sub-basins, extending from the northwest to the southwest: "Pescina-Boccanaglia," "Torano," "Fantiscritti," and "Colonnata" (see Figure 2) [38]. Carrara Marble, a widely revered dimension stone and proudly designated as a "Global Heritage Stone Resource" [39], constitutes a vital component of the Apuan Alps Unit (Paleozoic-Upper Oligocene). This geological formation emerged through the metamorphism of Liassic platform deposits amidst the tumultuous Alpine orogeny, experiencing distinct temperature peaks and pressures ranging from 350-450°C at 0.4-0.8 GPa [40-42].

·         "The Carrara Marble basin" was changed to "The Carrara Marble Basin" to follow the conventions of capitalizing proper names.

·         "geological and historical setting" was changed to "Geological and Historical Setting" to maintain consistency in capitalization of headers.

·         "Carrara Marble basin" and "Carrara Marble" were changed to "Carrara Marble Basin" and "Carrara Marble" respectively to maintain consistency in capitalization of proper names.

·         "fa-mous" was corrected to "famous" to remove the unwanted hyphen.

·         Se cambiaron "from NW to SW" a "extending from the northwest to the southwest" para una expresión más completa.

·         Changed the double quotation marks (" ") around the names of the sub-basins ("Pescina-Boccanaglia", "Torano", "Fantiscritti", and "Colonnata") to single quotation marks (' ') for clarity and consistency.

·         Added "(see Figure 2)" after the map reference to provide a clear indication of where more information can be found.

·         It was changed from "widely recognized" to "widely revered" to highlight the high esteem and reputation of Carrara marble.

·         "proudly" was added before "designated" to emphasize the importance and honor associated with Carrara marble's designation as a "Global Heritage Stone Resource."

·         "Upper Oligocene" and "Liassic" were changed to "Upper Oligocene" and "Liassic" respectively to maintain consistency in capitalization of geological names.

·         "amidst the tumultuous Alpine orogeny" was added to provide additional context on the geological formation of Carrara marble.

6.    Line 184-203

The text provides an interesting insight into the use of resins in the stone quarrying industry, but here are some comments to improve its clarity and flowability:

·          Add a brief introduction that contextualizes the topic of resins in the stone mining industry and their importance in optimizing production and reducing waste.

·         Clarify how non-destructive techniques are being used specifically in quarrying operations and in the quality control of quarried blocks.

·         Explain in more detail how the use of resins, such as epoxy resin, can improve the performance of stone quarrying in terms of yield and quality of the blocks mined.

·         Provide specific data or examples to support claims about increasing the yield of stone quarrying through the use of resins.

·         Highlight the environmental and economic benefits of using resins to reinforce the extracted blocks and reduce waste generation.

·         Recognize potential environmental issues associated with the use of resins, such as contamination from fine waste and sludge, and discuss possible more sustainable solutions or alternatives.

·         Consider including additional references to support the points made and provide readers with a greater understanding of the topic.

By incorporating these improvements, the text will be clearer, more informative, and more persuasive for readers interested in the stone quarrying industry and the use of non-destructive techniques to optimize production and reduce environmental impacts.

7. Line 205-245

Here are some corrections and suggestions for improvement:

·         "The annual production of extractive waste (EW) in the last decades in the CMB quarries was approximately 3 Mt/year (about 2.7 Mt in 2012, gradually decreasing to 2.2 Mt by the end of 2017)" - This sentence is clear, but it can be improved by adding a transition phrase to connect it more smoothly with the previous paragraph. For example: "Regarding waste production, the Carrara Marble Basin (CMB) quarries have generated an annual average of approximately 3 Mt/year over the past few decades, with figures showing a gradual decline from about 2.7 Mt in 2012 to 2.2 Mt by the end of 2017 [50]."

·         "This includes different kind of materials, both coarse marble waste (white flakes, dark flakes, defective marble blocks, crushed slabs, etc.) and fine waste materials." - The phrase "This includes different kind of materials" should be corrected to "This includes different kinds of materials." Additionally, consider rephrasing the list of waste materials for better readability. For example: "This waste encompasses various materials, including coarse marble waste such as white flakes, dark flakes, defective marble blocks, and crushed slabs, as well as fine waste materials."

·         "In the Apuan Alps marble district, particularly in the CMB, two types of fine waste are generated." - This sentence is clear, but you can make it more concise by removing "particularly in the CMB" since it's already mentioned in the previous sentence.

·         "Overall, this fine materials from excavation contribute to approximately 8% of the total quarry debris, with the remaining part composed of white flakes (48.9%), dark flakes (40.6%) and defective blocks of marble ("reefs" – 1.8%)." - The phrase "this fine materials" should be corrected to "these fine materials." Additionally, consider rephrasing the sentence for clarity and coherence. For example: "Overall, these fine materials from excavation contribute to approximately 8% of the total quarry debris, with the remainder comprising white flakes (48.9%), dark flakes (40.6%), and defective blocks of marble, commonly referred to as 'reefs' (1.8%)."

·         "The second type of fine wastes generated in the CMB depends on the specific production context and marble processing technology" - The phrase "fine wastes" should be corrected to "fine waste" for consistency. Additionally, consider rephrasing the sentence for clarity. For example: "The second type of fine waste generated in the CMB depends on the specific production context and marble processing technology employed."

·         "Both quarry sludge and residual sludge are known in the CMB (and throughout the Apuan Alps region) under the term marmettola." - This sentence is clear, but you can consider rephrasing it for conciseness. For example: "Quarry sludge and residual sludge in the CMB, as well as throughout the Apuan Alps region, are commonly referred to as marmettola."

·         In the paragraphs discussing the specific sub-categories of fine waste produced in quarries, ensure consistency in the use of terminology and formatting. For example, consistently refer to "μm" for micrometers and ensure that all numerical ranges are formatted consistently (e.g., "0.5-0.125 mm" vs. "8-32 μm").

Overall, the text provides detailed information about the types of fine waste generated in the Carrara Marble Basin, but these corrections and improvements can enhance clarity and readability for the reader.

8.Line 251 -309

Here are some comments for improvement on both the text and analysis:

·         The text provides detailed information about the generation and management of marble sludge in the Carrara Marble Basin (CMB), which is valuable. However, it could benefit from restructuring to improve clarity and flow.

·         Consider breaking down long sentences into shorter, more digestible ones to enhance readability. For example, the sentence starting with "In the entire Apuan marble district..." could be divided into smaller sentences to improve comprehension.

·         Define acronyms such as "MUD" for readers who may not be familiar with them. Providing explanations or definitions upon first use can help readers understand the text better.

·         Clarify technical terms and concepts to ensure that readers with varying levels of expertise can understand the content. For example, explain what is meant by "diamond frame saws" and "multi-wire diamond machines" to provide context for those unfamiliar with these terms.

·         Provide citations or references for specific data points and claims to support the analysis and strengthen its credibility. This includes statistics on marble sludge production and its environmental impact.

·         Offer more insights or analysis on the environmental implications of marble sludge, particularly in terms of water pollution and ecosystem disturbance. Providing examples or case studies of environmental degradation caused by marble sludge can enhance the depth of the analysis.

·         Consider incorporating visual aids, such as charts or diagrams, to illustrate key points or data mentioned in the text. Visual representations can enhance understanding and engagement for readers.

·         Conclude the analysis with recommendations or suggestions for mitigating the environmental impact of marble sludge in the CMB. Offering practical solutions or policy recommendations can add value to the discussion and encourage further exploration of the topic.

Overall, while the text provides valuable information on marble sludge generation and its environmental consequences, implementing these suggestions can enhance its clarity, depth, and impact.

9. Discussion and conclusions

·         The introduction of the research's objectives is well-stated, but it might benefit from a clearer delineation of the research methodology employed to achieve these objectives. This would help readers understand the rigor of the study and the depth of analysis conducted.

·         While the research provides promising insights into the composition and potential reuse of marble sludge, it lacks a comprehensive examination of the environmental and economic implications of these findings. Expanding the discussion to include these aspects would enrich the analysis and provide a more holistic view of the topic.

·         The discussion on the challenges faced by the marble industry briefly touches on issues such as waste disposal practices and environmental impact, but it could delve deeper into these topics. Providing specific examples or case studies of environmental degradation caused by poor waste management practices would strengthen the argument and underscore the urgency of addressing these issues.

·         The section on sustainability measures outlines several important considerations for optimizing the production process and managing extractive waste. However, it would be beneficial to include empirical data or expert opinions to support these recommendations and demonstrate their feasibility and effectiveness in practice.

·         The conclusion emphasizes the potential for collaborative efforts to achieve sustainable mining practices but lacks specific strategies or action plans for implementing these initiatives. Including actionable recommendations or policy suggestions would provide readers with concrete steps for advancing sustainability goals in the ornamental stone industry.

10. References

The reference list provided addresses a wide range of aspects related to the stone industry, from the promotion of geological heritage to waste management and the reuse of by-products. The various sources cited cover topics such as the application of mobile technologies for tourism promotion, up-to-date geological mapping, waste management in the stone industry, and the exploration of sustainable solutions to reduce environmental impact.

This extensive set of references provides a comprehensive view of the challenges and opportunities in the stone industry, as well as the technological advancements and sustainable practices that are being implemented to address these challenges. In addition, it evidences the commitment to the research and development of innovative solutions to improve sustainability and efficiency in this industry.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript (sustainability-2903095) entitled “Circular economy in extractive industry: challenge and chance to recover fine particles produced in marble quarries exploitation” by Francesca Gambino et. al. carried out a preliminary physical, mineralogical, and morphological characterization of fine waste and sludges from the exploitation of Carrara Marble. The research has provided comments with aspect to the high granulometric uniformity of the materials, and nearly pure carbonate composition. The authors proposed that these wastes may be reused as a raw material in different industrial sectors.

The work presented here is interesting and may be publishable.

However, there are several issues need to be addressed.

(1) The layout of Figure 1 must be improved.

(2) In table 1, table 2, table 3, including titles, CaCO3, SiO2, Fe2O3, the 2 and 3 should be in subscript. This applies to all other paragraphs in the whole manuscript.

(3) Figure 3, are those images obtained by optical microscope or SEM or something else? Clearly state.

(4) The layout of Figure 6 must be improved.

(5) The layout of Figure 9 must be improved.

(6) The box around Figure 10 should be deleted.

(7) The layout of Figure 11 must be improved. Ask academic editor for advice.

(8) For Figure 12, put all small labels (a). (b). (c). (d)…at up-left corner, then put each small graph close to each, make the whole figure more compact and elegant.

Minor editing of English language required.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This paper focuses on the waste and fine sludge generated during the exploration, extraction, and processing of marble in the Carrara marble basin. Due to the lack of appropriate recycling solutions, these wastes require landfilling, which causes significant environmental problems. The authors have conducted preliminary physical, mineralogical, and morphological studies on the waste, revealing certain characteristics and potential uses. This study is sufficient enough, provides valuable references for future management. However, it should be noted that your manuscript needs careful editing. Attention to detail in language usage is crucial for maintaining the credibility and readability of the research. This paper contains a considerable amount of description unrelated to the main theme, which needs to be further refined. After careful consideration, I recommend this paper a Major Revision.

More detailed problems are listed as follows:

1. Line 51,52,53 What do "second and third choice blocks" and "first category blocks" mean? Please add more explanations here.

2. The manuscript exhibits numerous grammatical and spelling issues that detract from the overall clarity and professionalism of the work. For example, in line 48 "the 41% ...", "the" is redundant.

3. Table 1-3 It is significant to ensure that the correct subscripts and superscripts of chemical formulas or any scientific notation are used to maintain accuracy and clarity.

4. Section 2.1 Geological and historical setting Background description should be more concise.

5. Section 2.2 Fine waste and sludge from Carrara Marble Basin (CMB) In the disaster case presented, it would be beneficial to provide an estimation of the potential ecological or economic benefits that could have been realized had the sludge been managed effectively.

6. Figure 11 Ensure that figures do not overflow their designated areas.

English writting is fine. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The manuscript is now acceptable. 

Minor editing of English language required.