Kaolin Mining Research Articles

The impact of kaolin mining activities on bacterial diversity and community structure in the rhizosphere soil of three local plants.

Thus far, the impact of kaolin mining activities on the surrounding native plants and rhizosphere microecology has not been fully understood. In this study, we used 16S rRNA high-throughput sequencing to examine the impact of kaolin mining on the rhizosphere bacterial communities and functions of three local plant species: Conyza bonariensis, Artemisia annua, and Dodonaea viscosa. The results showed that kaolin mining significantly reduced the diversity of rhizosphere bacteria in these plants, as indicated by the Shannon, Simpson, Chao1, and observed species indices (p < 0.05). Kaolin mining had an impact on the recruitment of three rhizosphere bacteria native to the area: Actinoplanes, RB41, and Mycobacterium. These bacteria were found to be more abundant in the rhizosphere soil of three local plants than in bulk soil, yet the mining of kaolin caused a decrease in their abundance (p < 0.05). Interestingly, Ralstonia was enriched in the rhizosphere of these plants found in kaolin mining areas, suggesting its resilience to environmental stress. Furthermore, the three plants had different dominant rhizosphere bacterial populations in kaolin mining areas, such as Nocardioides, Pseudarthrobacter, and Sphingomonas, likely due to the unique microecology of the plant rhizosphere. Kaolin mining activities also caused a shift in the functional diversity of rhizosphere bacteria in the three local plants, with each plant displaying different functions to cope with kaolin mining-induced stress, such as increased abundance of the GlpM family and glucan-binding domain. This study is the first to investigate the effects of kaolin mining on the rhizosphere microecology of local plants, thus contributing to the establishment of soil microecological health monitoring indicators to better control soil pollution in kaolin mining areas.

Facilitating the Critical Mineral Future: Valorization of Kaolin Mining Waste through Partnerships

Facilitating the Critical Mineral Future: Valorization of Kaolin Mining Waste through Partnerships

The Diversity and Community Composition of Three Plants' Rhizosphere Fungi in Kaolin Mining Areas.

Mining activities in the kaolin mining area have led to the disruption of the ecological health of the mining area and nearby soils, but the effects on the fungal communities in the rhizosphere soils of the plants are not clear. Three common plants (Conyza bonariensis, Artemisia annua, and Dodonaea viscosa) in kaolin mining areas were selected and analyzed their rhizosphere soil fungal communities using ITS sequencing. The alpha diversity indices (Chao1, Shannon, Simpson, observed-species, pielou-e) of the fungal communities decreased to different extents in different plants compared to the non-kauri mining area. The β-diversity (PCoA, NMDS) analysis showed that the rhizosphere soil fungal communities of the three plants in the kaolin mine area were significantly differentiated from those of the control plants grown in the non-kaolin mine area, and the extent of this differentiation varied among the plants. The analysis of fungal community composition showed that the dominant fungi in the rhizosphere fungi of C. bonariensis and A. annua changed, with an increase in the proportion of Mycosphaerella (genus) by about 20% in C. bonariensis and A. annua. An increase in the proportion of Didymella (genus) by 40% in D. viscosa was observed. At the same time, three plant rhizosphere soils were affected by kaolin mining activities with the appearance of new fungal genera Ochrocladosporium and Plenodomus. Predictive functional potential analysis of the samples revealed that a significant decrease in the potential of functions such as biosynthesis and glycolysis occurred in the rhizosphere fungal communities of kaolin-mined plants compared to non-kaolin-mined areas. The results show that heavy metals and plant species are the key factors influencing these changes, which suggests that selecting plants that can bring more abundant fungi can adapt to heavy metal contamination to restore soil ecology in the kaolin mining area.

Radiological Safety Assessment of Tailings Extracted from Kaolin Mining Sites in Katsina State

This research was carried out to sufficiently justify the recent increased awareness and concern for the potential hazards associated NORMs in the environment of the research around Kankara and Dutsin-ma Kaolin mining sites Katsina State; Nine (09) Kaolin samples were collected randomly from the mining sites for the study. The radioactivity analysis was done experimentally using NaI(TI) gamma spectrometer at Center for energy research and training, Ahmadu Bello University Zaria. The health hazards were evaluated using numerous radiological, Statistical and USEPA models. The overall hazard index (HI) was found to be 1.496609 for children found in third sampling point of Yar-goje are; it is the only possibility of a children to be affected while 0.799486 for adults, this value was below the USEPA threshold limit for non-carcinogenic risks of 1.0 indicating that the exposed population ages are unlikely to experience any adverse non-carcinogenic risks. The radiological parameters obtained are 226Ra (238U), 232Th and 40K of a NORMs with activity concentration of is 100.889, 0.129 and 224.040 (Bqkg-1) in the soil samples, at the studied area. Absorbed frequency in air measured in nGy/h by one-meter directly above the crushed, was considered, since the forbidding radioactivity concentrations is obtained as 77.575 while the total annual effective dose (AED) in mSv/y had average value of 0.099 in soil. The values obtained for external and internal radiological hazard indices Hext and Hint are 0.471 and 0.741 in soil; which were lower than the UNSCEAR suggested boundary limit of unity. Lastly, the overall excess lifetime cancer menace owed to NORMs, stood as 5.63E-06 and 4.15E-06 for whole populations indicating that (a maximum of 6 people/1 million may be affected) for adults while (a maximum of 4 people /1 million may be affected) for children. These values were within the USEPA threshold of 1E-04.

Natural Radionuclide Concentration in Kaolin Deposits and Dose Assessment Within Delta State, Nigeria

The assessment of natural radionuclide concentration in kaolin deposits and dose rate within Delta state, Nigeria has been carried out. Four kaolin mining sites within four Local Government Areas in the state were studied. Background Ionizing Radiation levels of each of the mining site was measured using a Gamma Scout handheld radiation meter and a GPS meter used to obtain the actual positions where the BIR levels were taken around each kaolin site. A total of twenty-five (25) samples were collected for Gamma spectrometry analysis at National Institute of Radiation Protection and Research, University of Ibadan. The mean BIR exposure rates for Ukwuani, Aniocha South, Ughelli North and Ughelli South LGAs were 0.01mRh -1 , 0.013mRh -1 , 0.013mRh -1 and 0.014mRh -1 respectively and were within the world’s recommended permissible limit of 0.013mRh -1 given by UNSCEAR. The mean activity concentrations of 238 U, 232 Th and 40 K in kaolin samples were estimated to be 137.028 ± 7.194, 13.532 ± 1.568 and 6.724 ± 0.396 Bqkg -1 respectively for Ukwuani; 425.494 ± 22.16, 18.63 ± 2.17 and 11.955 ± 0.71 Bqkg -1 respectively for Ughelli South; 596 ± 30.772, 18.728 ± 2.124 and 8.912 ± 0.526 Bqkg -1 respectively for Ughelli North and finally, 120.026 ± 6.235, 10.533 ± 1.182 and 15.024 ± 0.879 Bqkg -1 respectively for Aniocha South. These results compare quite well with the world’s average value of activity concentrations for natural radionuclides reported by UNSCEAR, except for 40 K which is higher than the world’s average at Ughelli North and South. The values of all the radiological hazard parameters for all the mining sites are less than the recommended limits. The calculated Excess Lifetime Cancer Risk also reveal that the values are all within the recommended limits, therefore, the risk of cancer inducement due to radiation exposure is within the acceptable limits for all the mining sites.

Assessment of Elemental Composition of Kaolin from Kankara and Dutsinma Mine Sites, Katsina State, Nigeria

This research aimed to assess the health hazards associated with heavy metals contamination around Kankara and Dutsinma Kaolin mining sites. The analysis was done by using Energy Dispersive X-ray Fluorescence (EDXRF) at the Central Laboratory, Umaru Musa Yar-adua University, Katsina. In which health hazards were evaluated. using numerous Statistical and United States Environmental Protection Agency (USEPA) models. Thirty nine (39) different elements were analyzed using the most associated environmental and health risk of priority in which seven (07) of them are heavy metals of interest; Among them are: Nickel (Ni), Copper (Cu), Zink (Zn), Thallium (Ti), Chromium (Cr), Lead (Pb), and Arsenic (As), with an average concentrations of 20.02, 12.59, 54.03, 1344.4, 21.94, 140.00, and Not Available Value (NA) in the studied area. The Values obtained for overall hazard index (HI) are within the accepted values by (USEPA) which indicates no cancer risk for both adults and Children. While the overall excess lifetime cancer risk for a heavy metal was 8.5555E-06 (a maximum of 9 people per 1 million may be affected) for children and 7.5773E-05 (a maximum of 8 people per 1 million may be affected) for adults.

Rare-Earth Minerals in Kaolin Ore, Mine Tailings, and Sands – Central Georgia, Upper Coastal Plain

AbstractThe total concentrations of rare-earth elements (REE) in the mined kaolin (0.02–0.06 wt.%), kaolin mine tailings (0.03–1.9 wt.%), and the kaolin-associated Marion Member sand lithology (0.03–4.6 wt.%) opened questions regarding the modes of occurrence of the REE and the role(s) of chemical weathering and secondary processes to explain the presence of REE in these materials. The REE were hosted primarily by phosphate minerals (monazite, xenotime) based on mineralogic analyses (scanning electron microscopy, X-ray diffraction). Enrichments in the light rare-earth elements (LREE: La–Gd) and the high correlation coefficient values were noted between P and the total REE concentrations (r2 = 0.99) for the sands and the mine tailings. Lower correlation coefficient values were noted between total REE concentrations and Zr (r2 = 0.31). The coarse fractions of the mined kaolins were enriched in the heavy rare-earth elements (HREE: Y, Tb–Lu) relative to the kaolin-associated sand lithologies. The REE inventory cannot be explained solely by mineral inheritance within the mined kaolins. Lower correlation coefficient values between P and total REE, positive Eu/Eu* anomalies, and the presence of xenotime overgrowths on zircon showed the importance of the role of chemical weathering of the detrital minerals during post-depositional processes (such as diagenesis) leading to redistributed and fractionated REE within the mined kaolin. The possibility of adsorption of the REE to kaolin mineral surfaces in the fine fraction of the mined kaolins remains open and permits further study to characterize fully the multi-modal fractionation of REE possible in the Georgia kaolin deposits.

Evaluation of Kaolin Mineral Emplacement at Amaihe-Ukpor, Anambra Basin, Southeastern Nigeria Using Spatial Layer Electrical Resistivity Tomography

Spatial layer Resistivity tomography was carried out at a Kaolin Mining site in Amaihe-Ukpor of Anambra Basin, southeastern Nigeria. The tomograms were obtained at various depths with the aim of assessing the depths of emplacement of the Kaolin at the site. Firstly, apparent resistivity data Schlumberger-B electrode configuration was obtained from Seventy-five (75) Vertical Electrical Tomography (VES) along 6 transverses at the site. Using the VES data, tomographic plots of spatial distribution of the Kaolin minerals at depths were obtained. Interpreted tomograms showed the occurrence of Kaolin minerals bearing apparent resistivity values in the range of about (900 - 28,900 Ωm) occurrence within the depth range of 0.5 m at layer 2 to 115 m at layer 4 of the site. The tomograms show that layers 2 to 5 indicate traces of the occurrence of Kaolin, layers 2, 3 and 4 particularly showed prominence of the Kaolin. Layers 1 and 6 show no trace of the Kaolin formation enrichment on them. The spatial layer tomograms showed that the prominence of the Kaolin remains at the site occur mostly at the northern and southern zones of the surveyed site. Further mining at the site could lead to tertiary exploitation of the mineral. The site is therefore in threat of gross depletion of the environment. Hence, there is need for suspension of the ongoing extraction of the Kaolin at the site to give room for deposition and sufficient formation of the target mineral.

Influences of digitalization on sustaining marine minerals: A path toward sustainable blue economy

This study's target is to experimentally discover the influence of the digital revolution, both for the public and private industries, on the sustainable development of marine mineral resources. As part of this initiative, it aims to demonstrate its influence on the development of a sustainable blue economy. Several measures are used to measure the blue economy sustainability of European countries. These measures include value added at the factor costs of crude oil extraction; gas extraction; activities related to oil and gas production; crushed stone or rock mining, clay or kaolin mining; salt extraction; as well as supporting activities engaged in the mining and quarry operations. We also use various indicators to capture digitalization performance in both the private and public sectors. During the 2009–2020 period, the European region will benefit from digital transformation in terms of improving marine minerals sustainability. Nevertheless, this effect is likely to be more apparent over the long term. Particularly, over a longer period, some aspects of digitalization in public services do have an empirically measurable effect on any components of marine minerals.

Assessment of Nickel and Arsenic Poisoning and Estimation of Cancer Risk from Kaolin Mining Sites in Dutsin-Ma and Kankara, Katsina State

This research was carried out to assess how poisonous are Nickel and Arsenic as heavy metals contaminated around Kankara and Dutsinma Kaolin mining sites. Nine (09) samples were collected randomly from the mining sites for the study. The analysis of such elements was done using Energy Dispersive X-ray Fluorescence {EDXRF} at Central Laboratory, Umaru Musa Yar-adua Universitty, Katsina, and The health hazards were evaluated using numerous Statistical and USEPA models. The result obtained was used to calculate the risk assessment of Nickel and Arsenic in the body via inhalation, ingestion, and body contact. In which the most associated environmental and health risk of priority have Their average concentrations as 20.02, 12.59, 54.03, 1344.4, 21.94, 140.00, and NA which is not identified element in the studied area. All results were below the USEPA threshold limit for non-carcinogenic risks of 1.0 indicating that the exposed population ages are unlikely to experience any adverse non-carcinogenic risks. The overall total excess lifetime cancer risk for heavy metals was 8.5555E-06 (a maximum of 9 people/1 million may be affected) for children and 7.5773E-05 (a maximum of 8 people /1 million may be affected) for adults. These values were within the USEPA threshold of 1E-04.

Optimum Fleet Selection Using Machine Learning Algorithms—Case Study: Zenouz Kaolin Mine

This paper presents the machine learning (ML) method, a novel approach that could be a profitable idea to optimize fleet management and achieve a sufficient output to reduce operational costs, by diminishing trucks’ queuing time and excavators’ idle time, based on the best selection of the fleet. The performance of this method was studied at the Zenouz kaolin mine to optimize the type of loader and the number of trucks used to supply the processing plant’s ore demands. Accordingly, five years’ data, such as dates, weather conditions, number of trucks, routes, loader types, and daily hauled ore, were collected, adapted, and processed to train the following five practical algorithms: linear regression, decision tree, K-nearest neighbour, random forest, and gradient boosting algorithm. By comparing the results of the algorithms, the gradient boosting decision tree algorithm was determined to be the best fit and predicted test data values with 85% accuracy. Subsequently, 11,322 data were imported into the machine as various scenarios and daily hauled minerals as output results were predicted for each working zone individually. Finally, the data which had the minimum variation from the selected required scheduled value, and its related data concerning loader type and the number of demanded trucks, were indicated for each day of the working year.

A study of environmental radioactivity measurement of selected Kaolin mining fields in Kwara, Nigeria

A study of environmental radioactivity measurement of selected Kaolin mining fields in Kwara, Nigeria

Are liming and pit size determining for tree species establishment in degraded areas by kaolin mining?

Mining contributes to the global economy on different scales and plays a fundamental role in the development of the goods and services sectors. However, the negative impacts caused by the activity are unavoidable, as they intensely degrade soil structures and modify landscapes. The use of native tree species has been effective in restoring the structure and functions of post-mining ecosystems in the Amazon. Thus, the objective of this work was to evaluate chemical indicators of soil quality, survival and initial growth of six tree species planted in degraded ecosystem by kaolin mining under the effects of liming in three pit volumes in the Eastern Amazon. The initial conditions indicated highly degraded soil, with acidic pH, low content of OM, P and K. Liming significantly reduced the level of toxic Al in the soil and provided Ca and Mg for the plants. Through Principal Component Analysis (PCA), we found that the two first components explained 69.30% of the variance of 13 functional indicators of soil quality. PC1 was positively correlated with Ca, Mg, K, SB, CEC and V% and negatively correlated with H+Al and Al saturation. Survival was higher than 80% for Clitoria fairchildiana in all treatments. Liming and pit volume were determining in growth, with high growth rates in height of Inga edulis, Inga cayennensis, Clitoria fairchildiana and Tachigali vulgaris. The species used in this study presented good initial development in restoring ecosystems after kaolin mining.

ECO FRIENDLY HIGH EARLY STRENGTH SELF COMPACTING CONCRETE USING KAOLIN AND WASTE MARBLE DUST

The growth and development of infrastructure in Indonesia is currently growing very rapidly, and the cement production process produces the second largest amount of carbon dioxide after waste, which plays an important role in the current global warming. Self compacting concrete is one of the biggest innovations in the field of construction, Self compacting concrete is one of the biggest innovations in the construction field, where this concrete has high workability but does not ignore compressive strength. Therefore, new, sustainable materials are needed to replace cement production, but they are also required for the workability required to make self-compacting concrete. Green concrete concept, the use of kaolin, and marble dust waste, can be a solution to replace some cement. This innovation research uses XRF or X-ray fluorescence methods to identify and analyze the constituent elements of self-compacting concrete innovations. In this study, self-compacting concrete was obtained using (marble dust waste) which replaced 15% cement, and kaolin which replaced 10% concrete waste. with the main element calcium oxide (CaO) and containing (SiO) can be used as an additive or partial replacement of cement in the manufacture of concrete and kaolin can be obtained from kaolin mines spread across Indonesia, and waste marble dust can be obtained from marble processing, for information 25% of the mass of marble will be lost in the cutting process obtained from marble companies in Solo Raya, the slump flow test measurement is carried out with reference to according to the rules of SNI 1972-2008 and the workability of self-compacting concrete also meets the required requirements. So it can be concluded that it can be a reference source by utilizing waste in Indonesia, easy to obtain, and effective.&#x0D; &#x0D; Keywords: Self-compacting concrete, waste marble dust, kaolin

Marketing Activities of Extractive Industry Enterprises in Ukraine in Overcoming the Consequences of the Corona Crisis

The study evaluated the state of international activities of extractive industry enterprises of Ukraine in the conditions of overcoming the consequences of corona crisis. The system of indicators to assess the effectiveness of their marketing activities in conditions caused by the pandemic coronavirus COVID-19 was developed. The evaluation system proposed in the study includes the analysis of indicators of production volume of the main types of extractive industry products, the dynamics of kaolin mining volumes in Ukraine and the dynamics of sales volumes of extractive industry products by Ukrainian enterprises on international markets. Also the structure of sales volumes of extractive industry products by Ukrainian enterprises on international markets was determined. An important stage of the proposed research methodology is the assessment of indicators of convergence of international markets in the conditions of overcoming the consequences of corona crisis. In the process of the study a comprehensive assessment of the convergence of Ukrainian enterprises of extractive industry in the conditions of overcoming the consequences of corona crisis was carried out. The approach is based on the application of ranks summation method for rating international markets by the system of dynamic indicators. The results of the study made it possible to determine the marketing attractiveness of markets of Belgium, Canada, Netherlands, Bangladesh, Hong Kong China, Pakistan for the activities of domestic enterprises of extractive industry at them, and assess their convergence. The last stage of the research was an expert assessment of convergence indicators of international markets in the conditions of overcoming the consequences of the coronocrisis. As a result of such assessment four international convergent markets were identified - Belgium, Canada, the Netherlands, Hong Kong, which demonstrate favorable conditions for doing business at them, and which indicates the existence of convergent conditions for domestic mining companies to sell the commodity group "2507 Kaolin and other kaolin clays" at the markets".

Sustainable conversion of Brazilian Amazon kaolin mining waste to zinc-based Linde Type A zeolites with antibacterial activity

Kaolin is a clay mineral with several applications, especially as filler in the paper industry. Brazil has the largest kaolin processing plant in the world located in the Amazon region. Kaolin mining activities generate high volumes of waste, resulting in additional costs and environmental impacts, and therefore, new approaches for their reduction are necessary. This work elucidates, for the first time, the technological valorization of abundant Amazon Brazilian kaolin mining waste to synthesize pure-phase zeolitic material with the antibacterial application. For the synthesis optimization, it was evaluated the influence of the type of kaolin (natural or thermally treated at 600 °C), the crystallization period (4, 6 and 24 h), the suppression of aluminum source (sodium aluminate) and the zinc ion-exchanging procedure. The materials were characterized by various techniques including powder X-ray diffraction (XRD), aluminum nuclear magnetic resonance with magic-angle spinning (27Al MAS NMR) and X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption isotherms, chemical analysis, thermogravimetric analysis (TGA), infrared spectroscopy (IR) and scanning electron microscopy (SEM). The results reveal that it is possible to direct the synthesis to the different zeolite structure with simple thermal treatment of the raw material, obtaining crystalline Linde Type A (LTA) or sodalite (SOD) zeolites using thermally treated or natural kaolin, respectively. Under the optimized synthesis conditions, the LTA zeolite was obtained after rapid crystallization in 6 h and without commercial aluminum supplementation. The Zn-exchanged LTA zeolites containing 4 and 7 wt% of Zn were applied as antibacterial materials. They presented growth inhibition zones between 7 and 8 mm for Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Salmonella enterica) while pure kaolin and LTA zeolite without Zn did not show antibacterial activity. These results offer new opportunities on the way that kaolin-mining industries manage their wastes.

Investigating Changes Driving Cumulative Impacts on Native Vegetation in Mining Regions in the Northeastern Brazilian Amazon

Developing conservation strategies to mitigate cumulative impacts requires the understanding of historic land use and land cover changes at the regional scale. By using a multisensory and multitemporal approach, we identified the major changes driving cumulative impacts on native vegetation in northeastern Amazon. Comparing two regions, one with mining as the key driver and another where mining is associated with other industrial activities (cellulose), we explore the land use and land cover historic dynamics and derive implications for the assessment of cumulative impacts. Transitions of forest cover to pastureland, silviculture, and urban expansion were mapped in detail over a 20-year period, revealing that silviculture growth cleared more forests than pastureland expansion when associated with pulp mill activities and kaolin mining. In contrast, in a region with gold and iron mining, pastureland expansion was more relevant, clearing mainly areas surrounding new roads. This research shows that the interplay of major mining and industrial investments can produce cumulative losses of native vegetation, depending on the associated industries and infrastructure required for the project development. Our findings emphasize that the definition of spatial and temporal boundaries for the assessment of cumulative impacts must consider different trends in impact accumulation and changes in their spatial distribution over time.

ОБҐРУНТУВАННЯ ДОЦІЛЬНОСТІ ЗАСТОСУВАННЯ МЕТОДУ ЗВОРОТНІХ ЗВАЖЕНИХ ВІДСТАНЕЙ ДЛЯ КЛАСТЕРИЗАЦІЇ ЙОСИПІВСЬКОГО РОДОВИЩА КАОЛІНУ

Purpose. To describe the procedure for performing kaolin deposit clustering in order to determine the regularities of the distribution of quality indicators, to distinguish promising areas and to calculate the volumes of minerals of different conditions. Methodology. Implementation of systematization, analysis and statistical processing of the results of geological research of the deposit. Identification of criteria for evaluating the qualitative properties of a mineral. Performing interpolation based on the results of geological studies in order to establish the qualitative indicators of the mineral and the regularities of their distribution within the deposit. Justification of the feasibility of using the method of inverse distances weighting to achieve the set goals. Performing deposit clustering and calculating the volume of reserves of different conditions. Results. The main result of deposit clustering is the direct identification of areas within which the secondary conditions of the mineral are located. The results of clustering allow: to display the content of constituent components in the contours of the deposit; identify promising areas for development; to determine the optimal direction of expansion of the mining operations front; determine the optimal location of overburden mining; calculate the volumes of minerals within the deposit under different trademarks; average the mining mass in order to improve its quality. Scientific novelty. The systematization and review of the existing methods of geometrization of mineral deposits has been carried out. The expediency of using the interpolation method to geometrize the complex structure of the Yosypiv deposit of primary kaolin has been investigated empirically. The expediency of using such a method has been substantiated, and the relevance of the obtained results has been assessed. Practical significance. The results obtained during the research make it possible to optimize the design process of a kaolin mining enterprise by obtaining a detailed and visual distribution of the deposit into clusters in accordance with the desired qualitative indicators: mineral composition, chemical composition, physical and mechanical indicators, etc. At the same time, the obtained results make it possible to predict the patterns of distribution of various types of properties within the deposit and to estimate the overall economic effect of its development with a higher degree of accuracy.

Kaolin mining waste to produce geopolymers: Physicomechanical properties and susceptibility to efflorescence formation

The kaolin mining waste (KW) is a residue generated during the purification process of extracting high purity kaolin used in different industries. KW is mainly constituted by kaolinite-rich clay and other secondary minerals such as anatase and quartz. With the appropriated and controlled process, calcined kaolin mining waste (CKW). It can be thermally activated by calcination to obtain a highly reactive metakaolinite rich material, which exhibits interesting pozzolanic properties. According to its chemical composition and high reactivity, this material is used as an aluminosilicate precursor in the production of geopolymers. One of the negative effects may be the formation of efflorescence. This paper evaluated geopolymer produced with CKW at different activation conditions (alkali concentration and sodium silicate content). The leaching of alkalis was studied through the development of efflorescence on the surface of hardened samples exposed to efflorescence formation conditions (contact with air and water). The results indicated that a larger activator provided a higher compressive strength and reduced the capillary absorption and the efflorescence formation. The data showed that the efflorescence formation can be appropriately controlled by adjusting the mix design parameters, especially the sodium silicate content.

Analysis of Controlled Blasting Technology in Coal Measure Kaolin Mining

Analysis of Controlled Blasting Technology in Coal Measure Kaolin Mining