Carsten Drebenstedt

Application of PCA, SVR, and ANFIS for modeling of rock fragmentation

Fragmentation has direct effects not only on the drilling and blasting costs but also on the economy of subsequent operations. In the present study, two soft computing-based models, so called “support vector machines (SVM)” and “adaptive neuro-fuzzy inference system (ANFIS)” were used and compared with Kuz-Ram method. In this regard, six effective parameters including specific charge, stemming length, total delays per number of rows ratio, hole diameter, spacing to burden ratio, and blastability index were considered as input parameters containing a database of 80 variables from the blasting operation of the Chadormalu iron mine of Iran. Principal component analysis (PCA) was performed to clarify the effective parameters on the fragmentation. As statistical indices, root mean square error (RMSE), correlation coefficient (R2), bias, variance account for (VAF), and mean absolute percentage error (MAPE) were used to evaluate the efficiency of the addressed models between measured and predicted values of rock fragmentation. The results confirmed the ANFIS and SVM as accurate predictive tools for rock fragmentation in open-pit mines. Correlation coefficient, bias, VAF, and MAPE generated by the ANFIS model (respectively 0.89, 0.257, 88.19, and 10.37) were higher than referred values for the SVM model (0.83, 1.87, 75.24, and 16.25, respectively) as well as Kuz-Ram inference.

Planungsgrundlagen der Wiedernutzbarmachung

Rohstoffe sind raumlich an die konkreten Lagerstatten gebunden. Im Gegensatz zu anderen Industriezweigen kann der Produktionsstandort nicht frei gewahlt werden. Entschliest man sich zur Gewinnung der Rohstoffe im Tagebaugebiet, bedeutet das einen tiefgreifenden Einschnitt in die bestehenden natur-, wirtschafts- und sozialraumlichen sowie kommunikativen und kulturellen Beziehungen in der betroffenen Region.

Hydro-geochemical paths of multi-layer groundwater system in coal mining regions — Using multivariate statistics and geochemical modeling approaches

Groundwater is an important drinking water resource that requires protection in North China. Coal mining industry in the area may influence the water quality evolution. To provide primary characterization of the hydrogeochemical processes and paths that control the water quality evolution, a complex multi-layer groundwater system in a coal mining area is investigated. Multivariate statistical methods involving hierarchical cluster analysis (HCA) and principal component analysis (PCA) are applied, 6 zones and 3 new principal components are classified as major reaction zones and reaction factors. By integrating HCA and PCA with hydrogeochemical correlations analysis, potential phases, reactions and connections between various zones are presented. Carbonates minerals, gypsum, clay minerals as well as atmosphere gases - CO2, H2O and NH3 are recognized as major reactants. Mixtures, evaporation, dissolution/precipitation of minerals and cation exchange are potential reactions. Inverse modeling is finally used, and it verifies the detailed processes and diverse paths. Consequently, 4 major paths are found controlling the variations of groundwater chemical properties. Shallow and deep groundwater is connected primarily by the flow of deep groundwater up through fractures and faults into the shallow aquifers. Mining does not impact the underlying aquifers that represent the most critical groundwater resource. But controls should be taken to block the mixing processes from highly polluted mine water. The paper highlights the complex hydrogeochemical evolution of a multi-layer groundwater system under mining impact, which could be applied to further groundwater quality management in the study area, as well as most of the other coalfields in North China.

A Prototype Decision Making Tool of Coal Mine Planning Using System Dynamics Model

The decision on investment in mining, particularly coal mining project is a complex decision system. Because of coal mining systems has many variables connected, and respond to each other such as production rate planning, mine life, stripping ratio, cost and income of mining, etc. So, it is not easy to know in mining time scale with automatic calculation responding, when some value of variables in coal mine planning change, what will happen with others. Moreover, if a variable change or multiple variables change, may give the different results. Thus, the complex variable system like in coal mine planning, cannot be solved easily in the general way, for example, calculates cover all possibility result, or discovering the optimal solution in the site condition criteria.

Mechanochemical Activation of the Ore and Coal Tailings in the Desintegrators

Russia have a world lead in the reserves of ores of ferrous metals, zinc, nickel titanium, tantalum, ranks second in the reserves of tungsten, niobium, gold and platinum-group metals, and ranks third in the reserves of copper, lead, molybdenum and rare metals. But the slump of production when export developing of strategic sorts of mineral raw materials has rebounded Russia to the level of the developing countries. The most rough passage has the production of the strategically important metals: tungsten, molybdenum, tin, lead and zinc.

Approaches for a Quality-Controlled Selective Mining in German Opencast Lignite Mines Using Different Sensor Technologies

Only a small part of the German lignite is used for material applications. Therefore the Technical University Bergakademie Freiberg is working with partners from the industry at a project called “ibi” (innovative brown-coal integration). The aim of the project is the interdisciplinary research on the material use of lignite. The main development goals are an operating diagram for selective mining of quality lignite as well as the development of sensor technology for material and boundary layer detection. The article gives an introduction how different sensors can be used to achieve these goals. Therefore the main working principles of these sensors will be explained as well as the idea how to attach one measuring device directly at the boom of a bucket-wheel excavator to measure and recognize the underneath lying surfaces or guiding layers. The consideration how the technology could work as an aid and the dividing layer recognition should occur is also further examined.

Gewässer in der Bergbaufolgelandschaft

Wie das gesamte Norddeutsche Flachland, so verdanken auch weite Gebiete der Lausitz die Pragung ihres landschaftlichen und geologischen Charakters in besonderem Mase den Inlandeis- und Schmelzwassermassen der quartaren Vereisungen. Demzufolge sind an ihrer Oberflachengestaltung uberwiegend Ablagerungen des Quartars beteiligt. In der Lausitz finden wir die gesamte glaziale Folge von Endmorane, Grundmorane, Sander und Urstromtal. Entsprechend vielseitig sind die wasserwirtschaftlichen Rahmenbedingungen wahrend der bergbaulichen Nutzung und der nachfolgenden Sanierung der Abbauraume von Braunkohle in der Lausitz. Nachfolgend soll — beginnend mit den pramontanen Ausgangsbedingungen — die jetzige hydrologische Situation und darauf aufbauend der notwendige Handlungsrahmen fur die anstehende Rekultivierung umrissen werden.

Indonesia economic output and employment impact of low rank coal utilization: An input output analysis

Indonesia is the largest exporter of steam coal. Domestic coal utilization still limited, and even for low rank coal (LRC) has not been used. On the other hand, the need for energy is increasing and now, Indonesia is an oil importer. Through Presidential Decree No. 5/2006 on National Energy Policy, Indonesia will take advantage of 33% coal and coal liquefaction by 2% of the total energy required in 2025. This policy will also reduce the use of oil to only 20%. In government policies, the LRC utilization is used as a source of energy for domestic purposes. Based on economic calculations, the LRC can be used as briquettes, electricity, coal water mixture or even LRC liquefaction. Nevertheless, the calculation of the economic benefits of widespread the utilization of the LRC has not been done. This paper aims to evaluate the economic impact of output and employment from the LRC utilization using input-output analysis by the latest data of The Indonesian Input Output Table 2008. The calculations show, all types of LRC utilization give high output effect among 9 other economic sectors. While the use of briquettes will provide the output, income and employment effects for the highest compared with the utilization of the power plant, brown coal liquefaction and coal water mixture.

The Responsible Mining Concept – Contributions on the Interface between Science and Practical Needs

The term “sustainable development” is today often pointed out like the main guideline for the development of the modern society.

Challenges in Modern Lignite Mining – Mass Management to Protect the Environment and the Budget

The densely populated Central German region in the south of Berlin is rich in lignite. In addition to an energetic use of the lignite, the material use of lignite will become more important in the future. Due to the annual excavation of 1 billion m3 of sediments, valuable land will be lost. Therefore, it is important to use edited dumps for the generation of reclamation areas. These dumps should have good geotechnical as well as geochemical conditions, considering the surrounding waters and to protect the receiving waters. Unfortunately, the overburden above the coal includes pyrite, which causes problems such as groundwater acidification and the discharge of sulfate, iron and trace metals. As the groundwater level in the future tipping of the open pits will rerise, it is important to investigate the influence of weathering of pyrite depositions (acid mine drainage), buffering by glacial till and of the resulting solutes on the surrounding water body. By superposing geochemistry and geology it is possible to mark main problem areas, improve buffer potentials by changing the technology and implement suitable technological countermeasures. In the future, this will significantly reduce the impact to the surrounding waters by material loads from the dump bodies. The optimal use of the existing buffering potentials can save a large amount of money, that otherwise would be necessary for the subsequent rehabilitation. The public authorities annually pay millions of € on remediation. The private mining operators are now responsible for bearing the costs by their own. Hence it is beneficial to invest technological know-how for mining operation to obtain significantly lower cost in the aftercare. The client MIBRAG mbH wants to turn from unstructured to a structured dump bodies with existing equipment of excavators, spreaders and conveyor belt systems only by the change of technology.