Study of Methods and Development of Technological Scheme for Heat Removal from Rock Waste Dump

The aim of this paper is to study the methods and develop technological scheme for thermal energy removal from coal mine rock waste dumps. The prospects of renewable energy sources development in Ukraine are analyzed. A number of available ways for using the sources of waste heat of mining enterprises, namely: outlet ventilation flow, mine water and other rock waste dumps, are investigated. The technological scheme of heat recovery from rock waste dump using heat pumps, which are component segments of the heat pump geosystem on the basis of borehole underground coal gasification, is developed

Overburden Dump Slope Stability: A Case Study At Coal Mine

Slope stability of overburden dumps plays as integral part of opencast mine project throughout the operation process. Waste dumps always have steep angled slopes as the waste has been tipped over from the top of the dump in a continuous and progressive manner. For new landfill it is often desirable to design steep slopes as it can accommodate the maximum amount of waste possible. The heavy machinery implanted for the extraction and transportation of wastes in the opencast mine whose management is of prime importance. The problems relating to overburden dump slope stability is catching attention for safe working in adverse natural constraints. This paper examines the influence of various parameters such as slope height, slope inclination, interfacial shearing resistance on the dump deposit. The analysis cover analysis of various sections of the waste dumps from the mine including material properties, strength values, bench height and angle. The evaluation of slope stability analyses in geotechnical analyses in geotechnical engineering has followed closely developments in soil and rock mechanics as a whole. Most of the design methods are purely based on field experience, followed by sound engineering judgment. During the last few decades, the concepts of slope stability analysis have emerged within the domain of rock and geotechnical engineering to address the problems of design and stability of dump slopes

Environmental Improvement Of Opencast Mining

Existing classifications of waste dumps in the quarries are given and their phenomenological nature is clarified. The need to identify the essence of the term "dump" is shown as well as the idea of "dump" as an artificial formation with everted and mixed rocks distanced from the quarry. Essential classification of man-made rock formations in quarries is developed. Characteristic of variations of man-made waste formations in quarries is developed. To reduce harmful effects of open-pit mining, dumps should be substituted with strat-lays - man-made structures relevant to natural stratification of litho-substances. Construction of strat-lays would improve ecological and technological culture of open cast mining

Hydro and geomechanical stability assessment of the bund wall bottom slope of the Dniprovsk tailing dump

Purpose. The objective is to assess the stability of bund wall components of a hydro-technical structure under the conditions of a tailing dump which hydrodynamic mode has been disrupted during operation. The specified data on the geomechanical state, physical and mechanical properties have been used of both the bund wall material and that of the soil base. Methods. Mathematical modeling by means of finite element method has been used to assess the hydro and geomechanical stability of bund wall components of a tailing dump (flood-breaking dam). The most reliable software Phase 2 v.8.0 was used for simulating. The modeling takes into consideration the influence of hydrostatic weighing forces and hydrodynamic pressure as well as nonstabilized state of water-logged rocks in the bund wall body. Findings. Based on the results of assessments, geomechanical stability margin of the bund wall components of a tailing dump has been determined. It has been shown that on an equal height of the bund wall, the areas with insigni-ficant angles of bottom slopes horizontal equivalent are characterized by the greater stability margin, and their resistance to shear deformation factor is comparable to the strength of alluvial sands shear in the base of a dam. In this context, stability margin is connected with the controlling influence on the bund wall state of water-logged soils, located above the ground water table in the dam body. Originality. It has been determined that the hydro and geomechanical state of the bund wall components of the hydro and technical structure is influenced by the occurrence within the bounds of the tailing dump bund wall of alternately water-logged rock material intervals located above the ground water fixed position. Practical implications. The results of modeling the tailing dump hydro and geomechanical state, which consider the multifactor conditioning of hydrodynamic and deformation processes in a body of the bund wall components, are the basis to substantiate a complex of engineering measures directed at the ensuring further safe operation of the hydro and technical structure.Мета. Оцінка стійкості огороджувальних елементів гідротехнічної споруди в умовах порушеного експлуатацією хвостосховища гідродинамічного режиму на підставі уточнених даних про геомаханічний стан і фізико-механічні властивості матеріалу огороджувальної дамби та ґрунтової основи. Методика. Для оцінки гідрогеомеханічної стійкості огороджувальних елементів хвостосховища (дамби обвалування) використано математичне моделювання методом кінцевих елементів за допомогою програмного пакету Phase 2 v.8.0, що враховує вплив сил гідростатичного зважування й гідродинамічного тиску, а також нестабілізованого стану водонасичених порід у тілі огороджувальної дамби. Результати. За результатами виконаних оцінок встановлено запас геомеханічної стійкості огороджувальних елементів хвостосховища “Дніпровське”. Виявлено, що при рівній висоті огороджувальної дамби великим запасом стійкості характеризуються ділянки з малими кутами закладення низових укосів, а їх опір розвитку зсувних деформацій можна порівняти з опором зрушення алювіальних пісків у основі дамби, при цьому, запас стійкості пов’язаний з визначальним впливом на стан огороджувальної дамби водонасичених ґрунтів, розташованих вище рівня ґрунтових вод у тілі дамби. Наукова новизна. Встановлено вплив на гідрогеомеханічний стан огороджувальних елементів гідротехнічної споруди наявності в межах огороджувальної дамби хвостосховища інтервалів змінно водонасиченого породного матеріалу, розташованого вище фіксованого положення рівня ґрунтових вод. Практична значимість. Результати моделювання гідрогеомеханіческого стану дамби хвостосховища, що враховують багатофакторну обумовленість гідродинамічних і деформаційних процесів у тілі огороджуючих елементів, складають основу для обґрунтування комплексу інженерних заходів, спрямованих на забезпечення подальшої безпечної експлуатації гідротехнічної споруди.Цель. Оценка устойчивости ограждающих элементов гидротехнического сооружения в условиях нарушенного эксплуатацией хвостохранилища гидродинамического режима на основании уточненных данных о геомеханическом состоянии и физико-механических свойствах материала ограждающей дамбы и грунтового основания. Методика. Для оценки гидрогеомеханической устойчивости ограждающих элементов хвостохранилища (дамбы обвалования) использовано математическое моделирование методом конечных элементов с помощью программного пакета Phase 2 v.8.0, учитывающее влияние сил гидростатического взвешивания и гидродинамического давления, а также нестабилизированного состояния водонасыщенных пород в теле ограждающей дамбы. Результаты. По результатам выполненных оценок установлен запас геомеханической устойчивости ограждающих элементов хвостохранилища “Днепровское”. Выявлено, что при равной высоте ограждающей дамбы большим запасом устойчивости характеризуются участки с малыми углами заложения низовых откосов, а их сопротивление развитию сдвиговых деформаций сопоставимо с сопротивлением сдвигу аллювиальных песков в основании дамбы, при этом, запас устойчивости связан с определяющим влиянием на состояние ограждающей дамбы водонасыщенных грунтов, расположенных выше уровня грунтовых воды в теле дамбы. Научная новизна. Установлено влияние на гидрогеомеханическое состояние ограждающих элементов гидротехнического сооружения наличия в пределах ограждающей дамбы хвостохранилища интервалов переменно водонасыщенного породного материала, расположенного выше фиксируемого положения уровня грунтовых вод. Практическая значимость. Результаты моделирования гидрогеомеханического состояния дамбы хвостохранилища, учитывающие многофакторную обусловленность гидродинамических и деформационных процессов в теле ограждающих элементов, составляют основу для обоснования комплекса инженерных мероприятий, направленных на обеспечение дальнейшей безопасной эксплуатации гидротехнического сооружения.The authors express particular gratitude to Oleksandr Boboshko, Chief Engineer of the state enterprise “Barier” for his help while carrying out the research and discussing the results

Case studies on the use of LiveLink for MATLAB for evaluation and optimization of the heat sources in experimental borehole

In the Czech part of the Upper Silesian Coal Basin (Moravian-Silesian region, Czech Republic), there are many deposits of endogenous combustion (e.g., localized burning soil bodies, landfills containing industrial waste, or slag rocks caused by mining processes). The Hedwig mining dump represents such an example of these sites where, besides the temperature and the concentrations of toxic gases, electric and non-electric quantities are also monitored within the frame of experimentally proposed and patented technology for heat collection (the so-called "Pershing" system). Based on these quantities, this paper deals with the determination and evaluation of negative heat sources and the optimization of the positive heat source dependent on measured temperatures within evaluation points or on a thermal profile. The optimization problem is defined based on a balance of the heat sources in the steady state while searching for a local minimum of the objective function for the heat source. From an implementation point of view, it is the interconnection of the numerical model of the heat collector in COMSOL with a user optimization algorithm in MATLAB using the LiveLink for MATLAB. The results are elaborated in five case studies based on the susceptibility testing of the numerical model by input data from the evaluation points. The tests were focused on the model behavior in terms of preprocessing for measurement data from each chamber of the heat collector and for the estimated value of temperature differences at 90% and 110% of the nominal value. It turned out that the numerical model is more sensitive to the estimates in comparison with the measured data of the chambers, and this finding does not depend on the type optimization algorithm. The validation of the model by the use of the mean-square error led to the finding of optimal value, also valid with respect to the other evaluation.Web of Science205art. no. 129

Особливості формування техногенних родовищ вапняку

Segregation laws become important in the formation of man-made deposits. The theoretical basis of the physical mechanism of the phenomenon of segregation of the rock mass in the formation of dumps and the storage of minerals or finished products in the embankments allow to take into account the initial distribution of the fractional composition of the rock mass, which has important practical application in the development of man-made deposits or shipments of finished products to the customer

Environmental Improvement Of Opencast Mining

Existing classifications of waste dumps in the quarries are given and their phenomenological nature is clarified. The need to identify the essence of the term "dump" is shown as well as the idea of "dump" as an artificial formation with everted and mixed rocks distanced from the quarry. Essential classification of man-made rock formations in quarries is developed. Characteristic of variations of man-made waste formations in quarries is developed. To reduce harmful effects of open-pit mining, dumps should be substituted with strat-lays - man-made structures relevant to natural stratification of litho-substances. Construction of strat-lays would improve ecological and technological culture of open cast mining

Ecological modelling of a wetland for phytoremediating Cu, Zn and Mn in a gold–copper mine site using Typha domingensis (Poales: Typhaceae) near Orange, NSW, Australia

Abstract: An artificial wetland was computationally modelled using STELLA®, a graphical programming tool for an Au–Cu mine site in Central-west NSW, the aim of which was to offer a predictive analysis of a proposed wetland for Cu, Zn and Mn removal using Typha domingensis as the agent. The model considers the important factors that impact phytoremediation of Cu, Zn and Mn. Simulations were performed to optimise the area of the wetland; concentration of Cu, Zn and Mn released from mine (AMD); and flow rates of water for maximum absorption of the metals. A scenario analysis indicates that at AMD = 0.75mg/L for Cu, Zn and Mn, 12.5, 8.6, and 357.9 kg of Cu, Zn and Mn, respectively, will be assimilated by the wetland in 35 years, which would be equivalent to 61 mg of Cu/kg, 70 mg of Zn/kg and 2,886 mg of Mn/kg of T. domingensis, respectively. However, should Cu, Zn and Mn in AMD increase to 3 mg/L, then 18.6 kg of Cu and 11.8 kg of Zn, respectively, will be assimilated in 35 years, whereas no substantial increase in absorption for Mn would occur. This indicates that 91 mg of Cu, 96 mg of Zn and 2917 mg of Mn will be assimilated for every kg of T. domingensis in the wetland. The best option for Cu storage would be to construct a wetland of 50,000 m2 area (AMD = 0.367 mg/L of Cu), which would capture 14.1 kg of Cu in 43 years, eventually releasing only 3.9 kg of Cu downstream. Simulations performed for a WA of 30,000 m2 indicate that for AMD = 0.367 mg/L of Zn, the wetland captures 6.2 kg, releasing only 3.5 kg downstream after 43 years; the concentration of Zn in the leachate would be 10.2 kg, making this the most efficient wetland amongst the options considered for phytoremediating Zn. This work will help mine managers and environmental researchers in developing an effective environmental management plan by focusing on phytoremediation, with a view at extracting Cu, Zn and Mn from the contaminated sites

Influence of vibrations on structures

One type of occasional structural load is a seismic load. Earthquakes and blasts are typical sources of vibrations, but vibration generated during urban tunnel construction can represent a significant problem. Evaluation of the harmful impact of vibrations transmitted through rock massif into buildings is solved using experimental measurements, detailed analyses of measured signals, knowledge of geological pattern and constructional analysis. Seismic load of structures due to earthquakes is solved using the EUROCODE 8 standard. The earthquake movements at a certain location on the surface are determined by an elastic response spectrum to the ground acceleration. Eurocode 8 puts emphasis especially on the robust foundations and simplicity of construction systems. It is also mentioned vibration effect on historical buildings and effect under the surface, for example, in mine spaces. Historical structures are usually even more prone to vibration damage than, for example, typical wood-frame homes. The greater concerns over historic structures arise from the design, structure age, building materials and building methods used. The peak values of vibration generated by earthquake decrease with depth; the decrease is faster in shallow layers compared with the deeper part. Technical vibrations differ from natural earthquakes, for a comparable value of maximum vibration amplitudes, especially in the frequency range of the signal and mostly its duration. Evaluation of technical seismicity is more complicated because there are usually used national standards. To document some common information about vibration effects on structures, some experimental measurements are presented. Examples of real wave patterns document common shapes and also signals with significant resonant vibrations. Very interesting is an example of resonant vibration that was generated as the influence of basin structures on the shape of wave patterns due to quarry blasts. To obtain complete information, measurement system has to keep sufficient parameters, especially the frequency range of the whole seismic channel, sampling frequency, and proper anchoring of the sensor. The basic methodology for evaluation of vibration on structures is outlined.Web of Science23331129