Eti Maden Kırka Sarıkaya Ocağında Patlatma Kaynaklı Parçalanmanın Değerlendirilmesi Ve Çok Sıralı Patlatma Tasarımı

Abstract

Patlatma açık ocak madenciliğinde en sık uygulanan üretim yöntemlerinin başında gelir. Bu amaçla kullanılan patlayıcı maddeler ile kazılması zor kayaç gevşetilir veya parçalanır. Patlatma sonrası oluşan parçalanmış kayacın boyutları çalışma verimliliği açısından önem taşır. İyi parçalanmamış zeminler için ikinci bir atım yapılması gerekebilir. Bu açıdan kayaç parçalanma analizlerinin dikkatle yapılması gerekmektedir. Patlayıcı maddelerin ateşlenmesi ile ortama büyük çaplı bir enerji salınımı gerçekleşir. Bu salınımlar sonucu başlıca yer sarsıntısı ve hava şoku olmak üzere çevresel olumsuz etkiler ortaya çıkmaktadır. Yer sarsıntısı ve hava şoku değerlerinin titizlikle ölçülmesi ve minimum seviyeye çekilmesi gereklidir. Bu tez kapsamında, saha çalışmaları Eti Maden Kırka Bor İşletmesi Sarıkaya açık ocağında gerçekleştirilmiştir. Sahanın jeolojik yapısına değinildikten sonra işletmedeki üretim yöntemleri hakkında bilgi verilmiş ve patlatma tasarım parametreleri, kullanılan patlayıcılar, ateşleme elemanları ve özelliklerinden bahsedilmiştir. Bu kapsamda işletme için teorik bir patlatma tasarımı hazırlanmış ve sahada uygulanan fiili parametreler ile kıyaslanmıştır. İşletmede atımlar sonrası yağının parça boyut dağılımı görüntü işleme yoluyla analiz edilmiştir. Ayrıca KuzRam ve KCO modelleri ile her bir yığının boyut dağılımı tahmin edilmiş ve ortalama parçalanma boyutu, karakteristik boyut ve uniformite katsayıları hesaplanmıştır. Görüntü işleme ile elde edilen sonuçlar ile parçalanma tahmin modelleri karşılaştırılmış; KuzRam ve KCO modellerinin Sarıkaya ocağında pratik olarak kullanılabilirliği araştırılmıştır. Sahada yapılan atımlar sonucu oluşan çevresel etkilerin tespiti için, yer sarsıntısı ve hava şoku ölçümleri gerçekleştirilmiştir. Burada ölçülen değerler çeşitli standartlar ve hasar kriterleri kullanılarak değerlendirilmiştir. Uzaklık, maksimum parcacık hızı, ölçekli mesafe ve frekans değerleri kullanılarak ölçümler analiz edilmiş ve atımların oluşturduğu çevresel etkiler irdelenmiştir. Son olarak Sarıkaya ocağı için açık ocak patlatma tasarım programı ile işletmede uygulanan atım parametrelerine sadık kalınarak çok sıralı patlatma tasarımları oluşturulmuştur. Oluşturulan bu tasarımlar ile yapılacak atımların enerji dağılımları, atımların yığılma yönleri gösterilmiş ve program yardımıyla parça boyut dağılım grafikleri oluşturulmuştur. Ayrıca yazılım yoluyla yer sarsıntısı analizleri gerçekleştirilmiştir.

Blasting is the most common rock excavation and production method that is applied in both surface and underground mines. Size distribution of muckpile affects all downstream processes such as, loading, transportation, crushing etc. Optimum fragmentation also eliminates secondary blasting needs. Therefore, analysis of blast fragmentation should be performed for an efficient mining operation. Some of the explosive energy is used for rock breakage. Some of the explosive energy creates environmental adverse effects. Main environmental effects of blasting are ground vibration and airblast. Ground vibration and airblast measurements should be performed regularly and environmental effect of rock blasting should be kept a minimum level. The purpose of this thesis is evaluation of blast fragmentation by site measurements and the fragmentation models. Also, ground vibration and airblast levels were measured and analyzed. The other target of this study is the creation of a multi-row blast design using computer aided design technique. In this thesis, all data were collected in Eti Mining Kırka Boron Works Sarikaya open pit mine. Rock formation, production method, blast design, explosives used and explosive properties were investigated in detail. A theoretical blast design was calculated for Eti Mining Sarikaya Mine. Sarikaya mine contains borate formation in central parts and it contains clay, carbonate, silica and tuffaceous rocks. Center of the unit is relatively flat and at the north it has quite rugged terrain and at the north-east and south-west it is observed as erosion remains high on the hill. The thickness of the unit ranges between 150-300 m and the thickness diminishes from central of area which includes borate to sides and different types of minerals are observed in borate zone. Borate zone in Sarikaya formation are covered with Tincal (Borax), a sodium borate mineral. Tincal zone is approximately 3500 m from north to south and it is about 800 m width from east to west. It has 50 m overburden thickness and about 70 m ore. The grade of Tincal is rich at the north side of mine, 26-29% B2O3. Low grade ore contains 20-23% B2O3. In this thesis, totally 18 bench blasts were observed. All the blast design parameters, bench height, burden, spacing between holes, stemming length, subdrilling, were strictly measured for each blast. Rock mass condition was examined for each bench. Hole diameter was 160 mm and hole length was 11m in Sarikaya mine. Holes are generally drilled as a single row. Numbers of the holes are determined according to production rate. Measured burden was 4.5-5 m. Spacing between holes was 5.5-6 m. Stemming length was 3 m. Blast holes were generally drilled as single row. Theoretical blast design was calculated by Olofssson’s approach. The measured and calculated blast design parameters were compared. In the mine, ANFO is charged for dry holes and emulsion type explosive is used for wet holes. In this study, image analysis software was used to determine size distribution of blast muckpile. Additionally, most applied fragmentation models, KuzRam and KCO, were used to predict size distribution of muckpile. The results of KuzRam and KCO models were compared. KuzRam model was established 1973 by combining Kuznetsov’s mean particle size prediction formula and Rosin Rammler size distribution curve. Also, a uniformity index is calculated using blast design parameters. Kuznetsov-Cunningham- Ouchterlony (KCO) model was created in recent years by Ouchterlony. The researcher proposed KCO model especially to define the fine size fraction of size distribution curve more precisely. KCO model utilizes Kuznetsov’s mean particle size prediction formula. However, KCO model uses a different curve equation to represent particle size distribution. First phase of image analysis is taking photograph from muckpile for rock fragmentation analysis on computer. Photographs were captured from different parts of muckpiles for an efficient analysis. Image sampling is done in two ways: Surface to be measured may be perpendicular to the line of observation or tilt images is captured. A scale should be replaced on the muckpile during image sampling. One scale might be enough for vertical images. Tilt images need at least two scales. First scale is replaced lower part of muckpile, second scale is replaced upper part of muckpile. All photographs are transferred to digital media after image sampling is done. Image analysis software creates a net for each image automatically. Then size of each rock fragments is determined based on the size of the scale. Software draw particle size distribution curve and calculates uniformity index, average size, sphericity etc. In this study, several images were captured from different parts of the muckpile. The results of the each analysis were combined and a single merged size distribution curve was created for each muckpile. A rock factor is needed to determine average particle size for KuzRam and KCO fragmentation models. In this thesis, measured particle size distribution curve was used to determine optimum rock factor value. The effect of the variation in rock factor on the mean particle size was also investigated. According to image analysis results, mean fragment size varies between 30.63 and 49.21 cm. Characteristic size is 38.03-61.66 cm. Uniformity index is between 1.57 and 1.98 cm. Size distribution curves obtained by KuzRam, KCO and image analysis technique are in accordance with each other. Calculated mean fragment size, characteristic size and uniformity index values by fragmentation models are close to the measured values. Especially, KuzRam model made successful predictions for size distribution. Mean deviation between measured and predicted mean fragment size is 3.81 cm. Mean uniformity index value calculated by KuzRam model is 1.52. Uniformity index values calculated by KuzRam model are lower than measured uniformity index by image analysis. Generally KCO model overestimates the fine size. It is very important to minimize the environmental effects of rock blasting. Optimum blast design should be created considering environmental adverse effects. Ground vibrations and airblast levels are measured by blasting seismograph in Sarikaya Boron mine. Blasting seismograph can measure vertical, horizontal and transverse components of ground vibration. Airblast levels are measured by a linear microphone. Measured values were analyzed by Blastware 8 software. Blast vibration was evaluated considering several vibration damage criteria. The measured frequencies were also examined and peak particle velocity versus frequency graphs were created based on US Bureau of Mines and DIN norms. The measured ground vibration were under limit values. Scaled distance approach was explained. Vibration prediction equations were created using five different scaled distance approach. Efficiency of vibration prediction equations was compared by absolute error. In this thesis, JKSimblast computer software is used to create multi−row blast designs. The software parameters were taken same as used in the field and explosives were chosen according to blast hole condition. Different delay patterns were applied and face displacement direction was investigated using the initiation time contours. Maximum instantaneous charge and total detonation duration were determined. Non-electric detonators were used as initiation system. Energy distributions were calculated for each blast and energy densities for cross sections are determined. The software was also used to create KuzRam Fragmentation Model. The site constants obtained by on-site ground vibration measurements were used to predict ground vibration. It is concluded that blast design software will be helpful for site engineers.