Coal Mine Site Research Articles

Application and characterization of new polymer dust suppression foam in coal mine and tunnel construction space

Severe dust pollution is common in tunnel, coal mine, and other construction sites. Dust suppression foam is a feasible method for dust suppression, but its single function makes it difficult to adapt to complex construction sites. Driving by reconstructing the molecular structure of ecological raw materials and strengthening the network function, a new method of SPI based gel foam dust suppression was proposed in this study. This method was realized through improving the performance of soy protein isolate (SPI) gel by glycosylation and further enhancing the fluidity and foaming performance of SPI by enzymatic hydrolysis. Afterwards, its reaction mechanism and dust suppression mechanism were analyzed. It was found that after the glycosylation of 0.4% SPI with 0.2% xanthan gum (XG) and the subsequent addition of 0.15% transglutaminase (TGase), a relatively stable double reinforcement network structure was generated. This structure was confirmed by Fourier transform infrared spectroscopy and other experiments; to be specific, its viscosity was reduced to 28.3mPa·s, and the foaming multiple was improved by 16.8% than SPI. The particle size of foam was observed to reduce to 20-60μm through a three-dimensional microscope, which is more conducive to wetting and capturing coal dust. Then, the prepared solution was compounded with 1.0% dodecyl dimethyl Amine oxide (OA-12) to develop a dust suppression gel foam and it was sprayed on the coal dust. Through experiments on the mine airflow-dust environment simulation platform, the dust suppression gel foam reached a PM10 suppression efficiency of 98.42%, and remained a total dust suppression efficiency of above 98% after 75 days. Moreover, the validity of the molecular model was confirmed by X-ray photoelectron spectroscopy. The molecular dynamics simulation showed that coal molecules with negative potential attract positively charged OA-12 molecules, and the tail group of OA-12 contacts the hydrophobic sites of the coal at an inclined angle, allowing water molecules to fully contact the coal molecules and improving the wettability; while gel molecules are adsorbed on the surface of coal molecules to play the role of bonding and filling. This research provides a theoretical support for the application of SPI based gel in the field of dust suppression, and develops an environmentally friendly and efficient feasible scheme for dust control in the construction site.

Bio-transfer and bioaccumulation patterns of heavy metals in mine site-inhabiting ants and grasshoppers, across mine site restoration chronosequence.

Soil is known to serve as a significant sink for heavy metals in coal mine sites, thus also influence the plant and other organisms of that area. Hence, the presence of heavy metals in coal mine soil is of concern to land managers. Insects occupy different trophic positions in the food chains, thus many insect species accumulate large amounts of heavy metals in their bodies and this is a matter of concern. In the present study, we investigated biotransfer and bioaccumulation of heavy metals from soil, grass species Cynodon dactylon, Vetiveria zizanioides, grasshopper species Gastrimargus africanus, Choroedocus robustus, ant species Cataglyphis longipedem and Camponotus compressus in six different ages (2, 4, 6, 8, 10 and 12 year old) of coal mine sites. Our study revealed that at some extent the heavy metal content and BAF patterns of heavy metals along different pathways (from soil to grass, soil to grasshoppers and from grass to grasshoppers) were not consistent and did not reflect the soil pollution status for all the metals, related to the mine spoil dump age. However, in contrast, ants successfully reflected a consistent pattern in the bioaccumulation of heavy metals via soil, thereby indicating the pollution status of the soil along with the restoration age of mine spoil dumps. Our study showed that ant species can successfully forecast the presence of heavy metals of coal mine spoils along with their restoration.

Carbon and nitrogen sequestration during primary succession in granodiorite quarries

AbstractStudies assessing the potential of mining areas for carbon sequestration focused mainly on areas after the extraction of energy raw materials, especially coal or oil shale, but little attention was paid to stone quarries and quarries of other non‐energy raw materials. We investigated carbon and nitrogen pools (stocks) along a chronosequence in the organic horizon and to a depth of 20 cm of the mineral soil in granodiorite quarries. We compared these pools and sequestration rates with other mining sites. The advantage of this study is that several differently aged quarries in a small area have the same rock chemistry and climate. Thus, the rate of pedogenesis is purely a function of time and vegetation. It is not affected by fossil organic matter or organic matter and nutrients in the topsoil used for reclamation. The vegetation succession tends towards tree cover dominated by Pine (Pinus sylvestris), Birch (Betula pendula), Willow (Salix caprea), Aspen (Populus tremula) and Alder (Alnus glutinosa). Analysis of soils from granodiorite quarries showed a natural accumulation of carbon and nitrogen in the soil to a depth of 20 cm during about 60 years of natural succession. The total soil organic carbon and nitrogen pools to a 20 cm depth average of 2482.4 g C m−2 and 179.1 g N m−2, respectively, in the oldest plots >50 years old. These values are for carbon 2.6 and nitrogen 2.4 times lower compared to pools in the same depth on control plots. Carbon and nitrogen stocks and sequestration rates are lower than in compared coal mining sites and spoils. The sequestration rates of the total sampled soil profile decreased with time from 57 g C m−2 year−1 and 4 g N m−2 year−1 for sites younger than 25 years to 46 g C m−2 year−1 and 3 g N m−2 year−1 for sites older than 50 years.

Slope stability analysis at coal mining sites in Central Kalimantan

Slope stability is an important factor in the planning and operation of open pits and mines. Currently the company has been mining up to a height of 20 meters. In the implementation of mining activities, the potential for landslides on the side walls of the slopes of sector X occurs on one of the slopes, namely at an elevation of +70 masl. The company made two design choices, one of which was confirmed by researchers in overcoming the potential for landslides. In carrying out slope analysis, information about the general properties of rock mass consists of testing the physical properties of rocks and testing the mechanical properties of rocks. The results of the safety factor analysis of the A-A cross-section with 2.476 saturated MAT (Stable) and dry MAT 3.159 (Stable), while the B-B cross-section with saturated MAT 2.161 (Stable) and dry MAT MAT is 2.771 (Stable). Meanwhile, for the two segments, A-A’ with saturated MAT of 2,459 (Stable) and dry MAT of 3,131 (Stable), while the B-B’ section with saturated MAT of 1,653 (Stable) and dry MAT of 2,464 (Stable). The researcher recommends using option 1 based on the safety factor value which shows a higher value.

Firms are planning clean ammonia

Yara Clean Ammonia has signed a letter of intent to develop a clean ammonia project in Texas with the energy firm Enbridge. The plant, which would be at Enbridge’s site near Corpus Christi, would have between 1.2 million and 1.4 million metric tons (t) of ammonia capacity per year and use carbon capture and storage to sequester 95% of its CO 2 output. The partners expect the complex to cost between $2.6 billion and $2.9 billion and start up by 2028. Separately, Adams Fork Energy and the Flandreau Santee Sioux Tribe are planning a clean ammonia facility for Mingo County, West Virginia. The plant, to be on a reclaimed coal mining site, would have 2.2 million t of ammonia output per year and would also use carbon capture and storage.

Spontaneously growing plants on revegetation sites of former coal mine in South Kalimantan Province, Indonesia

Abstract. Soendjoto MA, Riefani MK, Triwibowo D, Wahyudi F, Choirun D, Perdana YP. 2023. Spontaneously growing plants on revegetation sites of former coal mine in South Kalimantan Province, Indonesia. Biodiversitas 24: 1610-1620. Plants that grow and develop on the revegetation sites of post-coal mining are not only plant species that are intentionally planted, but also those that grow spontaneously. The aim of the research was to inventory plant species that grow spontaneously on revegetation sites of former coal mine sites in South Kalimantan Province and to analyze their presence mechanism and maintenance practices. Vegetation sampling was conducted on the plots established along the path with the size of each plot was 2 x 2 m2. All plants herbs (except grasses) and seedlings (shrubs, bushes, lianas and trees) within the plots were recorded and the vegetation composition was analyzed using Important Value Index as the parameter. Vegetation was monitored for 5 periods from 2018 to 2022 at the revegetation sites of two different planting years, i.e. 2016 and 2017. At Site-2016, 60 species belonging to 22 plant families were found and 71.67% of them grew spontaneously, while at Site-2017 there were 58 species belonging to 22 plant families and 70.69% of them were plants that grew spontaneously. Spontaneously growing species varied not only by location, but also by monitoring period. They are present at revegetation sites through seed dispersal mechanisms facilitated by natural activities (such as animals, wind, and water) as well as human activities. There are several management practices to facilitate vegetation succession, one of which is through spraying herbicides of weeds and invasive understorey species.

Anomalous concentrations of rare earth elements in acid mine drainage and implications for rare earth resources from late Permian coal seams in northern Guizhou

Rare earth elements (REEs) have attracted much attention in recent decades due to their growing applications in high-tech industries. Coal and acid mine drainage (AMD) are considered promising alternative sources due to their high concentrations of REEs. Here, AMD with anomalous REEs concentrations was reported in a coal-mine area in northern Guizhou, China. The AMD had a total concentration as high as 22.3 mg/l, suggesting that regional coal seams may be enriched with REEs. Five segments from borehole samples, which contained coal, rocks from the roof and floor of the coal seam were collected from the coal mine site to investigate the abundance, enrichment, and occurrence of REE-bearing minerals. Elemental analysis showed that the REE contents in the coal, mudstone and limestone from the coal seam roof, and claystone from the floor (all dating to the late Permian) varied greatly, with averages of 388, 549, 60.1 mg/kg and 2030 mg/kg, respectively. Encouragingly, the REEs content in the claystone is over an order of magnitude higher than the average content reported in most other coal-based materials. The enrichment of REEs resources in regional coal seams is particularly associated with the contribution of REEs in the claystone that comprises the coal seam floor, rather than just the coal, as considered in previous studies. The minerals in these claystone samples were dominated by kaolinite, pyrite, quartz and anatase. Two types of REE-bearing minerals, bastnaesite and monazite, were detected in the claystone samples by SEM–EDS analysis, and they were found to be adsorbed by a large amount of clay minerals, mainly kaolinite. Additionally, the results of chemical sequential extraction also confirmed that the majority of the REEs in the claystone samples are mainly in their ion-exchangeable, metal oxide and acid-soluble forms, which are viable prospects for REE extraction. Therefore, the anomalous concentrations of REEs and most of them are in extractable phases, which demonstrates that the claystone from the floor of the late Permian coal seam should be a potential secondary source of REEs. Future studies will further consider the extraction model and the economic benefits of REEs from the floor claystone samples.

Detection and mapping of vegetation stress using AVIRIS-NG hyperspectral imagery in coal mining sites

This paper primarily focuses on identifying and mapping vegetation stress caused by the impact of coal mining using airborne hyperspectral image (AVIRIS-NG) at a fine scale level and is validated using spectroscopic field data. In this work, we have calculated and tested vegetation stress-affected narrow banded vegetation indices (VIs) based on Separability (S) and Coefficient of discrimination (R2) statistical tests for the identification of suitable vegetation stress indices. We have considered the highest S and R2 values of stress indices for weighted and vegetation combined pixels’ analysis. The final weighted combination index has been used for vegetation stress detection and mapping in coal mining sites. The outcome has been validated using field-based healthy and stress-affected plant spectral data and compared to ENVI software's agriculture stress tool (AST) based vegetation stress result. Some indices exhibited higher performance for vegetation stress analysis (NDVI, NSI-2, SR-1, SWST-3, SRWI, NWI-2, CSVI, HMSSI, and ARI-1), according to statistical results (S and R2) of VIs. Based on the vegetation stress index, high-stress zones are located in and around the mines whilelow-stress regions are positioned farther from the mines. The findings additionally demonstrated that the VIs-based stress result (AUC-0.69) fits the data more accurately than the ENVI's AST result (AUC-0.61). The VI’s-based stress index had a clearly negative correlation with the distance of vegetation from the mines, which could be verified using the on-field NIR spectral measurements. Therefore, effective vegetation health monitoring and planning in coal mining sites might benefit from these results .

Estimation of in-situ rock strength from borehole geophysical logs in Australian coal mine sites

This study aims to improve the conventional empirical rock strength estimation method that is widely adopted in the Australian coal mining industry and provide more accurate rock uniaxial compression strength (UCS) predictions based on artificial neural network (ANN) models. 274 laboratory-measured UCS data (sample dimension: 60 mm (diameter) × 150 mm (height)) were collected from two longwall coal mines in Australia, along with the four geophysical logs (sonic, gamma, neutron, and porosity logs) and rock density of the tested core specimens. A two-layer ANN model was developed from these data based on the Levenberg–Marquardt algorithm as a base model. As compared to conventional sonic-UCS fitting equations, the mean percentage error, root mean squared error and maximum absolute error of the proposed ANN model were reduced from 34.27%, 15.23 MPa and 70.66 MPa to 20.67%, 11.02 MPa and 47.66 MPa, respectively. Further investigations were conducted by splitting the dataset based on rock lithology and mine locations, and separate ANN models were developed based on the divided subsets. Both lithology-specific and site-specific models exhibited improved estimation accuracy in comparison to the base model, indicating lithology and local geological conditions could considerably affect the estimation accuracy. Among the three types of models, the lithology-specific models yielded the most accurate predictions over the 274 data (MPE: 17.55%; RMSE: 8.84 MPa), followed by the site-specific models and the base model in descending order. Overall, all three models significantly outperformed the current empirical methods adopted in the studied mine sites. The outcomes of this study could provide more accurate UCS predictions for further geotechnical analysis in underground constructions, such as tunnel stability analysis and estimating in-situ stresses based on borehole breakout.

Applied Methodological Approach for the Assessment of Soil Contamination by Trace Elements around Abandoned Coal Mines—A Case Study of the Jerada Coal Mine, Morocco

Previously conducted studies have established that soil contamination by trace elements (TEs) around coal mines affects ecological biodiversity and human health. One of the ways to protect the health of the surrounding population of coal mine sites is through the assessment of contamination impacts by accurate procedures for the establishment of relevant reclamation plan. The aim of the study is to develop an applied methodological approach to easily assess and quantify the impact of coal mining on the surrounding soils. To achieve this goal, a set of relevant geochemical indexes (enrichment factor—EF, geochemical background—GB, and geoaccumulation index—Igeo) and a geostatistical interpolation for mapping soil contamination were applied. It is experimentally established that the process of combining these techniques can be of great interest in highlighting the anomalous areas and revealing the contamination sources. A case study has been carried out on of the abandoned coal Jerada mine site in Morocco. Soils and coal mine waste rocks (CMWR) samples were collected from this site. Soil and CMWR samples were analyzed for their geochemical content. CMWRs were characterized further for their mineralogical composition and environmental behavior. Based on the EF, three TEs (As, Pb, and Zn) were targeted. The results of GB and Igeo calculations have established an evident relationship between the CMWR dump and the occurred soil contamination. TEs distribution pattern has been revealed using the obtained geochemical maps. The developed methodological approach may be in high demand when assessing soil contamination in most of abandoned coal mine sites around the word.

A Study on Physico Chemical Properties of the Soil in the Gautham Khani Open Cast Mine Kothagudem Coal Fields Region, Telangana

The soil quality refers to a broad range of physical, chemical, and biological characteristics that maintain environmental quality, productivity, and microbial proliferation, the soil samples are collected from Gautham Khani Open Cast Mine it was located in Goutampur Village, Chunchupalli Madal, Badradri Kothagudem District in Telanagan State. The texture of the soil sample, physical properties like bulk density, porosity, water holding capacity as well as chemical properties like pH, electrical conductivity, organic carbon and macronutrients like N, P, K are analysed in the soil samples, As a result, the study analyzed soil samples and observed that study area soils need the restoration to improve the soil quality In order to evaluate the condition of the soil in coal mining sites for reclamation methods.

Diversity and Heavy Metal Tolerance of Fungi Associated with Different Coal Overburden Strata of Tikak Colliery, Assam.

Coal mine overburdens are generally highly acidic and contaminated with toxic heavy metals. Here, we studied the culturable fungal diversity associated with different coal overburden strata (OBS) of Assam, India, and assessed their heavy metal tolerance ability against five different heavy metals viz., As3+, Cd2+, Cr6+, Cu2+, and Ni2+. Among 15 distinct coal OBS considered in this study which spans a depth of ~ 35m from the ground surface, the isolation of fungi was successful only from 11 OBS samples and the colony-forming unit (CFU) counts were highly variable among the samples. A total of 66 fungal pure cultures were isolated which belong to 18 genera (17 known and 1 unknown) under 15 families and two divisions i.e., Ascomycota (89.4%) and Basidiomycota (10.6%). Acidiella bohemica was found relatively the most abundant species followed by Rhodotorula toruloides. A good number of fungal isolates was found tolerant to the test heavy metals at concentrations ≥ 1mM. Findings of some multi-metallotolerant fungal isolates along with a tolerance up to 5mM concentration of As3+, and up to 10mM each of Cu2+, Cr6+, Ni2+ and Cd2+ were noteworthy in the present study that could be useful in the management of heavy metal pollution or stress. Cultivable fungal diversity of coal mine overburden strata of Tikak colliery, Margherita, Assam, India. It shows a photograph of the coal mining site as the background, front view of the fungal colonies in the upper section, and a graphical representation of heavy metal tolerance of the isolates at different concentrations of As, Cd, Cr, Cu, and Ni in the lower section.

Plant nutrient contents and spatial distribution patterns of toxic element concentrations in mine site soils

Open-pit coal mining causes land and soil degradation and negatively affects soil properties. It is of great importance to determine variabilities in soil properties of the abandoned area after the mine is closed and to bring it back to nature by implementing appropriate rehabilitation programs. The aim of this study was to evaluate plant nutrient availability and toxic element pollution in an abandoned coal mine site. The results indicated that the amounts of plant-available P and K are quite low (<90 kg P2O5 ha-1) and low to moderate (<170 kg K2O ha-1), respectively. The concentrations of plant available Fe (>4.5 mg kg-1) and Cu (>0.2 mg kg-1) are too high in the whole study site. Soils in the study area generally have low organic matter content with ranging from 0.42% to 3.67%. Toxic element concentrations, especially Ni (>75 mg kg-1) and Cr (>100 mg kg-1), are extremely above the optimum levels, posing a great risk in the open-pit area (abandoned), the dump sites and the coal storage area.

Impact of Kara-Keche lignite mining on the Kara-Keche River water composition and properties

On the evidence of the earlier research findings, as well as the full-scale and lab-scale test data of 2019&ndash;2020, this article describes the ecological situation at Kara-Keche lignite field being developed by five mining companies in the Jumgal district of the Naryn Region in the Kyrgyz Republic. It is found that the field development proceeds with insufficient adherence to legal documents and has a considerable adverse influence on the environment and water bodies. Many large-volume refuse dumps have no isolation from natural water bodies, which ends with acute pollution of the latter. Contamination of local rivers exists both below the coal mining sites and above them, because of winnowing of coal dust. The river water has the increased pollution indexes&mdash;the coliform indexes are 55&ndash;70, even in winter, and in summer, these indexes reach a few thousands units. The solid residue, suspended matters, chemical oxygen demand as well as the carbonate and total hardnesses at the points below the major pollution sources as against the averaged values at the points located above the pollution sources have very high values: 14% for the chemical oxygen demand; 43 for the dry residue; 86 and 35 for the carbonate and total hardness, respectively; 108 % for the suspended matter. The concentrations of all macro elements&ndash;cations (and anions) grow at a relatively small distance (~5 km) below the major pollution sources: by 11.2 % for sodium; 22 % for potassium 42.2 % for calcium and 79.9 % for magnesium. The analyses revealed no one of 22 trace elements (Ag, As, B, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, P, Pb, S, Sb, Se, Sn, Ti, U, V, W, Zn) in the Kara-Keche river water, supposedly, because of low sensitivity of the spectrometer. The concentrations of some trace elements (aluminum and barium) are noticeably lower (almost by 2 times) below the major pollution sources. The concentrations of the other trace elements at the points below the major pollution sources are higher than the averaged values at the points above the pollution sources: by 2.2 % for silicon; by 28.3 % for iron; by 76 % for strontium and by 83.4 % for lithium.

Designation of Batu Arang, Selangor as the coal mining and Geological Heritage Site: issues and challenges

PurposeThe paper explores the roles of involved organizations in the designation of Batu Arang in Gombak, Selangor, Malaysia, as the Coal Mining and Geological Heritage Site, the heritage significance selected as the elements of its designation and the challenges faced by the involved stakeholders during the designation process.Design/methodology/approachThe primary research material is derived from the documentation review on the final draft of the Special Area Plan (RKK) of Batu Arang and the final draft of the Geopark Management Plan, field investigation on the heritage significances and interviews with the involved organizations: the Selayang Municipal Council (MPS), the State of Selangor Malay Custom and Heritage Corporation (PADAT) and the Village Community Management Council (MPKK) of Batu Arang.FindingsThis paper found that Batu Arang has the potential to be developed as an important heritage mining site and heritage tourism destination; however, many of the heritage significances are being demolished, invaded and abandoned due to human aggression or effects of nature. In addition, it reveals the roles of each involved organization, issues that occurred and challenges faced by the organizations during the designation process as a heritage site, namely in terms of management, property ownership and promotion.Originality/valueThe paper outlines that a heritage mining site like Batu Arang should be considered an important heritage as well as other heritage sites in Malaysia, and issues and challenges faced during the designation process should be discussed critically to ensure that these heritage significances will not be neglected and abandoned.

Effects of recultivation on soil organic carbon sequestration in abandoned coal mining sites: a meta-analysis

Opencast coal mining results in high loss of soil organic carbon (SOC), which may be restored via recultivation. Common strategies include liming, topsoil application, and phytoremediation. It remains unclear, however, which parameters determine the effectiveness of these varying recultivation strategies especially regarding SOC sequestration. This meta-analysis analyses the effect of varying recultivation strategies on SOC sequestration under different climate and soil conditions (pH, texture, depth) as well as in relation to time, based on 404 data entries from 51 studies. All included climatic regions recorded increases in SOC stocks, with tropical soils showing the highest potential for relative gains at up to 637%. We demonstrate that loamy soils sequester twice as much newly introduced SOC than sand. Strategy-wise, the highest mean rate of SOC sequestration is achieved by forest after topsoil application (3.9 Mg ha−1 a−1), agriculture after topsoil application (2.3 Mg ha−1 a−1), and agriculture with topsoil and fertiliser application (1.9 Mg ha−1 a−1) with a response ratio of 304%, 281%, and 218%, respectively. Soils analysed to less then 40 cm depth show higher SOC sequestration rates (< 10 cm: 0.6 Mg ha−1 a−1, < 20 cm: 1.0 Mg ha−1 a−1, and 20–40 cm: 0.4 Mg ha−1 a−1; response ratio of 123%, 68%, and 73%, respectively) than those analysed to a depth of 41–80 cm (0.1 Mg ha−1 a−1; response ratio of 6%). In terms of pH, strongly acidic soils (pH < 4.5) and alkaline conditions (pH > 7) offer the most beneficial environment for SOC sequestration at 0.4 Mg ha−1 a−1 and 0.8 Mg ha−1 a−1, respectively (185% and 273% response). Given comparable SOC sequestration potentials of forest after topsoil application, agriculture without amendments, and forest without amendments, we recommend to weigh these strategies against each other. Potentially decisive aspects are short- vs. long-term economic gains, food security concerns, and—in case of agriculture—the risk of overintensification leading to losses in SOC. Our data suggests that amendments exert considerable influence on SOC sequestration and need to be introduced under careful consideration.

Performance analysis and socio-enviro-economic feasibility study of a new hybrid energy system-based decarbonization approach for coal mine sites

The mining sector contributes to 4–7 % of global GHG emissions, of which 1 % are from scope 1 and scope 2 emissions, caused by operations such as electricity consumption used for the mining process. China heavily relies on coal for power generation, and the energy demand for coal production in the country is primarily met by fossil-based electricity. In addition, the transportation of the mined coal to various destinations within the supply chain is achieved by fossil fuel-powered transport systems. These daily activities of the Chinese coal sector further compound foreign and domestic pressure on China to limit its carbon emissions. The current study attempts to provide a solution to the situation by investigating the feasibility of adopting renewable energy sources for the process of coal mining in Northern China. The selected coal mine is one out of 643 coal mines in Shanxi Province, with a combined production capacity of ∼1 billion tonnes of coal per annum. In addition, the excess electricity generated has been designated to produce hydrogen on-site as a refueling source for hydrogen fuelled-trucks to replace diesel fuelled-trucks in transporting coal. The analysis has been completed using HOMER Pro software, and the key contributions are summarized as follows. 4 different scenarios comprising of standalone solar photovoltaic, wind turbine, and diesel generator have been designed in the current study to serve a daily load of 215 MWh and 2.4 t of electricity for coal mining and hydrogen for transport of 100 % of the mined coal by road using hydrogen fuel cell trucks, respectively. A technical, economic, environmental, and social feasibility analysis have been investigated in the present work. A grid-tied system is subsequently added to the base scenario and the results are compared against the base system in an attempt to identify the more feasible option between the two systems. Also, a sensitivity analysis has been conducted to reveal the performance of the base system amidst future uncertainties. The findings in the current work could prove beneficial to China's quest to reach carbon peak by 2030 and achieve carbon neutrality by 2060.

Monitoring as a tool to evaluate preservation possibilities. Results from the CULTCOAST project

The CULTCOAST research project has installed environmental monitoring equipment at two cultural heritage sites in northern Norway: one at the coal mine site of Hiorthhamn on Svalbard, one at the settlement mound site Sjåberget on Andøya in Nordland County. Both these coastal heritage sites are situated north of the Arctic circle, in the areas most impacted by climate change. Whereas the global temperature increase since 1970 is just above 1°C, in Svalbard the increase is now 4°C. This is the first example of using this specific type of sensors to monitor the ongoing changes and their possible impacts on preservation of heritage sites.

Prospects of carbon fiber composites applications in hydraulic supports

This paper briefly analyzes the current development of lightweight design and applications for hydraulic support in the coal mines. Specifically, the comparative investigations of lightweight design demonstrate the potential application for carbon fiber reinforced composites (CFRP) in the production and manufacturing process of hydraulic support. After analyzing the major industrial applications of CFRP in the three main parts, hydraulic structure, cylinder and special frames, it demonstrated the feasibility of the potential CFRP exploitations in the future research of hydraulic support for coal mining sites.

Porous Blasting Morphology and Resistivity Response Characteristics of Soft Coal Seam

The fracturing characteristics of multi-holes blasting in soft coal seam were analyzed quantitatively by using the multi-holes model blasting experiment of soft coal seam and digital image processing (DIP) and electrical resistivity tomography (ERT) techniques, and the electrical resistivity response rules before and after blasting were obtained. The results show the following: (1) At the same time as the formation of blasting-induced cracks, the coal inside the control hole presents two kinds of displacement phenomena: crack and noncrack, partially offsetting the extrusion effect caused by the expansion of the blasting hole. (2) The comprehensive value (S) of blasting-induced cracks, control hole, and blasting hole area change is proposed to analyze the blasting effect. When single-hole blasting is performed, S &lt; 0, the fractal dimension change rate of coal seam crack is only 5%, the control area presents a compaction phenomenon, and the resistivity decreases by about 20%. When multi-hole blasting is performed, the blasting cracks are abundant and the coal displaces sufficiently. The fractal dimension of cracks reaches 21.28%, the negative effect of the blast holes cavity is offset (S &gt; 0), and the resistivity in the controlled area generally increases by 1 to 30 times. (3) Compared with the single-hole blasting model, the multi-hole blasting is more in line with the coal mine site, and can effectively increase the permeability in the control area, and the resistivity generally increases.