The development of sustainable grouting materials is essential for enhancing underground strata stability while reducing the environmental impact associated with ordinary Portland cement (OPC). This review summarizes previously published studies on alkali-activated grouting materials (AAGMs) prepared using fly ash (FA) and ground granulated blast furnace slag (GGBFS), activated by sodium hydroxide and sodium silicate solutions. A comprehensive literature-based analysis was conducted to evaluate both fresh and hardened properties, including fluidity, setting time, yield stress, compressive strength, and durability-related performance. Particular attention was given to the influence of FA-GGBFS proportions and activator composition on rheological behaviour, mechanical performance, and engineering applicability. The reviewed studies indicate that increasing GGBFS content significantly accelerates geo-polymerization and setting behaviour and enhances early-age strength development due to its higher calcium reactivity. In contrast, FA contributes to improved workability and flowability, attributed owing to its spherical particle morphology and slower reaction kinetics. The reviewed literature further suggests that balanced FA–GGBFS alkali-activated systems can provide a favourable combination of fluidity, injectability, setting behaviour, and mechanical performance, making them particularly suitable for underground grouting and rock mass reinforcement applications. Compared with conventional OPC-based grouts, AAGMs demonstrate superior mechanical performance together reduced environmental impact through the utilization of industrial by-products and reduced clinker consumption. However, several critical challenges still hinder the large-scale implementation of alkali-activated grouting materials in underground mining, particularly with respect to field-scale validation, shrinkage mitigation, safe handling of alkaline activators, and the current lack of standardized specifications and design guidelines for underground grouting applications. These findings provide a robust scientific basis for the design and application of eco-efficient grouting materials in deep underground mining environments and support the advancement of sustainable practices in underground engineering.

Underground coal gasification (UCG) requires rigorous geological suitability evaluation to reduce project risks, and scientific site selection is critical for success. Taking the No. 15 coal seam in the Yushe–Wuxiang Block (Qinshui Basin) as the focus, this study evaluates the feasibility of deep UCG using a multi-criteria decision-making framework. A hierarchical evaluation model comprising four primary and 10 secondary geological indicators (e.g., coal thickness, parting coefficient, fault fractal dimension, roof lithology) was constructed. Subjective weights were derived from the Analytic Hierarchy Process (AHP) and combined with objective weights from the coefficient of variation method. The TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method was then applied to rank seven development units. Results indicate that the No. 15 coal seam has reasonable potential for UCG implementation. The most favorable areas (Blocks II and VII) are characterized by thick coal seams (>5 m), low parting coefficients (<8%), simple fault networks (fractal dimension ≤0.5–1.05), and competent mudstone roofs. Blocks III, V, and VI are moderately favorable, while Blocks I and IV are marginally favorable. These findings provide a prioritized roadmap for pilot-scale UCG testing in the Yushe–Wuxiang Block.

To investigate the interaction between mine ventilation and the thermal en-vironment in a fully mechanized longwall face, a Computational Fluid Dy-namics (CFD) model was developed for the 11-3107 working face of Menkeqing Coal Mine based on field-measured data. The model was used to analyze the effects of ventilation mode, electromechanical equipment layout, roadway length, airflow velocity, and inlet air temperature on the thermal environment of the working face. The results show that changing the ventilation mode alone has only a limited effect on reducing the maximum face temperature, although the U-shaped system provides a comparatively practical ventilation arrange-ment under the studied conditions. Locating major electromechanical equipment in the return airway helps reduce the temperature in the intake airway and working face. Shorter ventilation routes, higher airflow velocity, and lower inlet air temperature all contribute to improved thermal conditions. Considering both simulation results and operational constraints, cooling equipment should be installed near the intake airway to effectively lower the working-face temper-ature. Based on psychrometric analysis and ventilation parameters, the required cooling load for the 11-3107 fully mechanized working face was determined to be 2417 kW under normal conditions and 3082 kW under critical conditions, in-cluding a 20% safety margin. The study provides a numerical basis for venti-lation optimization, cooling-system design, and heat-hazard control in deep underground coal mines.

Purpose: The present research aims to establish the involvement of nanotechnology in increasing the rate of oil recovery and the management of reservoirs in the oil and gas business. However, there is still a gap within the state of knowledge on what the practical form of nanotechnologies is, how effective they are in the actual practical context, and how nanotechnologies are viewed by practical practitioners. The study is geared towards establishing the extent to which practising professionals in the petroleum engineering field know about nanotechnology and its applicability, as well as how they appraise the effectiveness of the concept.Objective: In this study; the specific aim will be to indicate the level of knowledge on nanotechnology among professionals working in the petroleum industries, establish their perception of the effectiveness of nanotechnology in enhancing oil recovery and managing hydrocarbon reservoirs, and lastly determine the challenges owing to cost factors, technical considerations and environmental impacts that hinder full adoption of nanotechnology in the petroleum industries.Methodology: A descriptive research design was conducted using a structured questionnaire from 200 professionals working in the petroleum industry. Authorized through another set of close-ended questions with emphasis on awareness, familiarity, and perceived effectiveness of nanotechnology. Statistical analysis was performed by using chi-square tests, Mann-Whitney U tests, ordinal regression, and Spearman correlation coefficients. Descriptive data was presented with graphs and tables and bar charts and box plots were used in displaying the data.Results: The significant value of the chi-square test is 2.34 and its p-value is 0.674. Hence no significant relationship between the variables of awareness of nanotechnology and perceived oil recovery effectiveness can be concluded. The Mann-Whitney U test described no significant difference in the perceived reservoir management effectiveness by participants who applied nanotechnology (U = 5133.00, p = 0.647) and those who did not. The ordinal logistic regression model results did not reveal any significant predictors of the effectiveness of oil recovery about awareness (coefficient = 0.2, p = 0.330) or familiarity (coefficient = -0.5, p = 0.330) had a log-likelihood of - 319.24. After conducting the Spearman correlation coefficient test, it was noted that the relationship between awareness and effectiveness of oil recovery is negative and weak and the results are statistically insignificant (r = -0.063, p = 0.372). These results imply that awareness and familiarity with nanotechnology do not significantly determine their perception of the effectiveness of nanotechnology.Practical Implications: This thesis underlines the necessity of collecting proofs of nanotechnology usage to promote the application of such technology across the world. Education and awareness promotion efforts will not be adequate; instead, stakeholders of the industry should concentrate on actual proof of nanotechnology in large-scale field tests. The current study also suggests the call to reduce the cost of production because the cost is still prohibitive and there is an urgent need to evaluate environmental effects when it comes to the application of nanotechnology in the petroleum industry.Novelty: The present work offers a perspective on the use of nanotechnology in petroleum engineering by focusing the analysis on the practitioners’ point of view, rather than presenting more or less contrived practical examples and equations of filtration theories. In this respect, the study adds to the practicality of existing literature, which is essential for further investigations of nanotechnology applications in oil recovery and reservoir management. Conclusion: The present research also suggests that concerning its applicability in the field of petroleum engineering, awareness and familiarity do not necessarily lead to a positive perception of its effectiveness. From the present study, it is noted that adequate efforts should be made to show the usefulness of nanotechnology for general applications through field applications and explore the challenges associated with its implementation, including cost and environmental aspects. More research should be directed toward following up the effects of this technology in enhanced recovery of oil and the development of guidelines to govern nanotechnology’s use.