In the evolving landscape of environmental science and sustainable resource management, the recovery and reuse of underground spaces have garnered intense attention. A groundbreaking study by Li and Chen introduces a novel approach to enhance mine water reinjection through acidizing dissolution and permeability improvement, combined with an innovative proposal for CO₂-water co-storage. This pioneering work not only addresses long-standing challenges related to permeability restoration in fractured rock formations but also presents new avenues for carbon dioxide sequestration, offering dual environmental and operational benefits.
The core of this research revolves around the intricate chemistry and physics that govern acidizing processes in subsurface environments. Acidizing, traditionally applied in petroleum and geothermal industries, involves the injection of acid to dissolve rock minerals, thereby increasing the permeability of the formation. Li and Chen take this mechanism further by investigating its application under mine water reinjection scenarios, where water—often contaminated and rich in dissolved gases—is reintroduced into mining voids or fractured rock networks for environmental management and mine stabilization.
One of the paramount challenges in mine water reinjection systems is maintaining or enhancing the permeability of the formation to ensure efficient fluid flow and containment. Over time, mineral precipitation and clogging can severely reduce permeability, leading to operational inefficiencies and increased environmental risks. The study meticulously details how acidizing agents, when correctly formulated and controlled, can dissolve specific mineral phases within the fractures, effectively clearing pathways for water movement and improving the overall hydraulic conductivity of the rock.
Crucially, the researchers incorporate the role of CO₂ in this process, not merely as a byproduct or contaminant but as a strategic co-agent for storage. Injecting a mixture of CO₂ and water into fractured formations leverages the natural chemistry of carbonic acid formation, which further assists in mineral dissolution. This synergistic interaction enables enhanced permeability while simultaneously providing a means to sequester CO₂ underground—a critical factor in global climate mitigation strategies.
The experimental setup and simulation models outlined in the paper demonstrate a comprehensive approach, combining laboratory acid dissolution tests with advanced numerical modeling of multi-phase fluid flow and reactive transport. These sophisticated simulations elucidate how acid diffusion and CO₂ concentration gradients influence dissolution rates and patterns, revealing the dynamic interplay between chemical reactivity and physical transport in complex fracture networks.
One remarkable finding from their results is the identification of threshold conditions under which dissolution shifts from uniform to highly localized patterns, known as wormholing. This phenomenon, characterized by the development of preferential flow channels, drastically increases permeability but comes with the challenge of controlling it to avoid over-dissolution or structural weakening. Li and Chen’s analysis provides critical insights into balancing acid volume, injection rates, and CO₂ concentration to optimize this effect for practical engineering applications.
Beyond the purely mechanistic understanding, the study delves into the environmental implications of such interventions. The co-storage of CO₂ with mine water reinjection addresses two problems simultaneously: mitigating the ecological impact of mine water disposal and contributing to carbon capture and storage (CCS) efforts. By turning traditional reinjection from a remediation task into a carbon management opportunity, this approach exemplifies a paradigm shift in subsurface engineering.
Furthermore, the study highlights the potential for tailored acidizing solutions adapted to specific mineralogical characteristics of mine sites. Since mineral compositions vary widely between different geological settings, the customization of acid formulas can maximize dissolution efficiency while minimizing unwanted side reactions and secondary mineral precipitation. This adaptability is crucial for scaling the technology across diverse mining operations globally.
The implications of enhanced permeability through acidizing dissolution extend beyond mine water reinjection. Improved hydraulic connectivity can facilitate enhanced resource recovery, such as in geothermal energy extraction or subsurface hydrological management. Additionally, by improving the injectivity and containment properties of fractured formations, this technique paves the way for safer and more effective underground CO₂ sequestration projects.
Li and Chen also address the operational challenges involved in implementing acidizing with CO₂ water mixtures in active mines. Managing reaction kinetics, ensuring precise control over injection parameters, and monitoring the evolving subsurface chemistry require advanced instrumentation and real-time data analytics—areas that are rapidly progressing with modern sensing technologies.
The visualization presented in their study captures the essence of the process, illustrating how injected acid and CO₂ fluids interact within the fracture system, creating dissolution channels that facilitate fluid transport and gas storage. This depiction underscores the complexity and potential of engineered subsurface interventions, marrying chemistry, geology, and engineering disciplines.
In summary, this pioneering research opens new frontiers in the sustainable management of mine environments and CO₂ emissions, presenting a multifaceted solution that benefits both environmental protection and resource utilization. As the global community intensifies efforts towards climate change mitigation, innovations like those introduced by Li and Chen will play critical roles in transforming underground spaces into active components of our clean energy and environmental strategies.
The promise of this technology lies in its ability to marry the enhancement of permeability—a traditionally challenging technical problem—with climate action goals, creating a dual-purpose strategy that could revolutionize how mines manage their water and emissions. The future applications may even extend to other industrial subsurface operations, making acidizing dissolution under CO₂-water co-storage a versatile and vital tool in the green engineering toolkit.
As research continues, the integration of real-world pilot studies, long-term monitoring, and lifecycle impact assessments will be essential to verify theoretical models and laboratory findings. The scalability and economic feasibility of this technology in various mining contexts remain to be fully demonstrated, but the pathway laid out by this study is unquestionably promising.
In closing, the study by Li and Chen vividly demonstrates how innovative scientific inquiry can unlock hidden synergies in environmental management. By rethinking the role of acidizing in mine water reinjection and coupling it with CO₂ sequestration, they chart a course that aligns technical possibility with ecological necessity, inspiring further innovation in subsurface science.
Subject of Research: Acidizing dissolution and permeability enhancement mechanisms during mine water reinjection, with a focus on CO₂-water co-storage for environmental remediation and carbon sequestration.
Article Title: Acidizing dissolution and permeability enhancement mechanisms under mine water reinjection: CO₂-water Co-storage propose.
Article References:
Li, X., Chen, G. Acidizing dissolution and permeability enhancement mechanisms under mine water reinjection: CO₂-water Co-storage propose. Environ Earth Sci 84, 545 (2025). https://doi.org/10.1007/s12665-025-12588-4
Image Credits: AI Generated
