Conference Object | 2007 | PROCEEDINGS OF THE 20TH INTERNATIONAL MINING CONGRESS AND EXHIBITION OF TURKEY, NO 132 , pp.207 - 214
20th International Mining Congress and Exhibition of Turkey (IMCET 2007) -- JUN 06-08, 2007 -- Ankara, TURKEY WOS: 000248289300020
Conference Object | 2007 | PROCEEDINGS OF THE 20TH INTERNATIONAL MINING CONGRESS AND EXHIBITION OF TURKEY, NO 132 , pp.217 - 224
In this study, unaxial compressive strength, indirect (Brazilian) tensile strength and dirilling rate index (DRI) have been carried out on the rock samples colected 16 different area. The drilling rate index of rocks was assessed on the basis of two laboratory tets, the brittleness test and Sievers' miniature drill test. Three brittleness concepts, which are used two brittlenes measurements acceppted (B1, 132) in literature, together with a new brittleness concept (B3) were used in order to determine of brittleness of rocks. A meaningful relationships between the measuring brittleness of B1 and B2 and drilling rate index were not fo . . .und. A exponential relationship between brittleness of B3 and drilling rate index was found. The effect of brittleness on drillability can be clearly observationed by the time the third brittleness concept uses in drillability analyses Daha fazlası Daha az
Hacifazlioglu, H. | Toroglu, I.
Conference Object | 2007 | PROCEEDINGS OF THE 20TH INTERNATIONAL MINING CONGRESS AND EXHIBITION OF TURKEY, NO 132 , pp.73 - 79
In this study, the enrichment of the Zonguldak fine coal by using a homemade pilot-scale Jameson flotation cell was investigated. In the result of the experimental studies, a clean coal product ash 12.60% was produced from the 46.70% ash feed with a 77.61% combustible recovery by applying only scavenger stage. Besides, Jameson flotation cell design and operating parameters were optimized for coal flotation. These parameters were the nozzle height Jet length), the immersion depth of the downcomer, the collector amount, the frother amount, the percentage of solids and the rate of wash water.
Korkmaz, T. | Erdogan, E. | Bostanci, A.
Conference Object | 2007 | PROCEEDINGS OF THE 20TH INTERNATIONAL MINING CONGRESS AND EXHIBITION OF TURKEY, NO 132 , pp.281 - 293
All over the world in recent years, energy products are exposed to high price volatility due to the increasing deregulation and liberalization efforts in energy sector, imbalance of supply and demand, increasing needs of energy, storage-delivery problems and etc. Price fluctuations have negative affect on both suppliers and consumers operating in energy markets; as a result, price risk needs to be hedged. One of the effective ways of price risk hedging purposes is using VaR methods. VaR is a generally accepted method that assesses price risk in a single number by using statistical and simulation models. In this study, hypothetical e . . .nergy futures contracts portfolio's daily risk numbers are measured by VaR methods, namely; Historical Simulation and Monte Carlo Simulation. In order to test success of daily VaR numbers, backtesing method is applied. As a result, it is observed that both Historical Simulation and Monte Carlo Simulation methods meet the requirements of Basel Criterion Daha fazlası Daha az
Oezarslan, A. | Genis, M. | Bilir, M. E. | Oezkan, I.
Conference Object | 2007 | PROCEEDINGS OF THE 20TH INTERNATIONAL MINING CONGRESS AND EXHIBITION OF TURKEY, NO 132 , pp.49 - 58
Underground openings should meet the stability requirements conforming with their function during their service life. The design of underground salt caverns requires the analysis of stability of cavern over the planned use (e.g. salt extraction, storage of gas and oil) and operating conditions. The most important parameters to be taken into consideration in the design of a salt cavern are; depth, in situ stresses, cavern geometry, internal pressure conditions, mechanical (strength, deformation and rheological) properties of rock salt. In salt caverns for storage purposes, the internal cavern pressure has to be set at a value such th . . .at failure and fracturing of the surrounding rock, which increases the permeability, can be avoided. Also, the time dependent creep behavior of rock salt must be given consideration when determining the design and operation parameters of salt caverns. In the study, numerical analyses has been performed for determination of dilation and failure zones occurring around modelled oil storage caverns with regard to different operating conditions. Finite difference FLAC(2D) software has been used for the analyses Daha fazlası Daha az