Total station survey monitoring through an observation window: a systematic error correction to remove the effects of glass properties

Total stations are used extensively for taking geodetic and engineering survey measurements. These measurements are made possible by accurate observation of targeted points. One example is deformation surveys, slope stability monitoring, in mines. Continuous monitoring necessitates sheltering or housing the instrument to protect it against harsh weather conditions that are characteristic of mining environments. Previous studies carried out by Afeni and Cawood (2012) revealed that the properties of the glass material matters when using a total station to take observations through a glass window of a structure that houses the total station at a mine. This study briefly discusses total station survey monitoring and developed systematic error correction formula to reduce the effect of glass properties, such as thickness and colour, on distance measurements through a shelter window glass in a surface mine environment. Each developed formula is combined with the atmospheric corrections formula given by Leica Geosystem, who is the manufacturer of the total station used in this research, to form a combined atmospheric and glass correction formula. The formula performed well when tested on two sets of observations

Design and Fabrication of ANFO Mixing Machine for Safety and Proper Homogenization

The project is focused on the design and fabrication of ANFO mixing machine for safety and proper homogenization of ammonium nitrate and fuel oil in order to increase its production rate. The ANFO mixing machine is a replacement for the manual mixing of fuel oil (Diesel) and ammonium nitrates in bays or on concrete floors which is the common method of mixing ANFO in Nigeria. But the ANFO mixing machine designed is easy to operate, safe to use, increases production and reduces number of laborers. Keywords: Explosive, ANFO, Design, Fabrication, and Performance Evaluatio

Microsoft paint imaging system – a photogrammetric approach to fragmentation measurement in rock and aggregate production

Purpose. To evaluate the fragment sizes of blasted material using Microsoft paint imaging system. It focuses on digital imaging fragmentation analysis of rocks and aggregates using the Microsoft paint, putting into consideration, the camera’s specifications to define the fragment size. Methods. Five blast tests were conducted in the field to examine the effectiveness of this method of fragmentation analysis and also investigate the influence of burden, spacing and specific charge on degree of fragmentation. Findings. The particle size distribution obtained from Microsoft-paint imaging analysis shows that the mean run-off-mine sizes are 0.6, 0.58, 0.42, 0.36 and 0.54 m, and the average boulder sizes of fragmented particles are 1.19, 1.11, 0.93, 0.81 and 1.03 m, for blast test 1, blast test 2, blast test 3, blast test 4 and blast test 5 respectively. Blast test 1 produced the highest boulder size of 1.15 m followed by blast test 2 while blast test 4 has the minimum boulder size. The results also shows that with increasing burden and spacing distances, the mean run-off-mine size, average boulder particle size increased. As expected, the mean run-off-mine size, average boulder size also decreased as specific charge increases. Originality. The results of this research can be compared to fragmentation analysis using analytical software such as Wipfrag, Blastfrag, Fragscan, Powersieve, e.t.c. Practical implications. Microsoft paint imaging system can be used as a fragmentation analytical tool. Thus, results of the fragmentation analysis can be used for better decision making in future blast designs of a mine.Мета. Оцінка гранулометричного складу зруйнованої вибухом гірської породи із використанням системи створення зображень зображення Microsoft. Методика. Були проведені п’ять вибухових випробувань в польових умовах гранітного кар’єру для підтвердження ефективності даного методу гранулометричного аналізу та вивчення впливу лінії найменшого опору (ЛНО), відстані між шпурами і певного заряду на ступінь дроблення. Гранулометричний склад визначався із використанням сервісу Microsoft за авторською методикою. Гранулометричний аналіз цифрового зображення породи та щебню із використанням сервісу Microsoft здійснено з урахуванням технічних характеристик камери, які дозволяють визначати розмір шматків. Результати. Розподіл обсягів частинок, отриманий за допомогою аналізу зображень Microsoft, показує, що середній розмір частинок, що розлетілися, дорівнює 0.60, 0.57, 0.43, 0.39 і 0.55 м, при цьому середній розмір великих уламків дорівнює 1.15, 1.07, 0.97, 0.83 і 1.02 м для 1, 2, 3, 4 і 5 вибуху відповідно. Визначено, що при першому вибуху були отримані найбільші уламки розміром 1.15 м, трохи менші – під час третього вибуху, і найменші – під час четвертого вибуху. Результати випробувань свідчать, що при збільшенні ЛНО та відстані між шпурами середній розмір частинок, що розлетілися, і середній розмір великих уламків збільшується, і зменшується при збільшенні окремо взятого заряду. Наукова новизна. Надано оцінку гранулометричного складу підірваної породи із використанням сервісу Microsoft і встановлено, що метод можна порівняти з гранулометричним аналізом, виконаним за допомогою Wipfrag, Blastfrag, Fragscan, Powersieve, та характеризується достатньою достовірністю. Практична значимість. Система створення зображень Microsoft може бути використана як інструмент гранулометричного аналізу. Результати гранулометричного аналізу будуть сприяти прийняттю більш ефективних рішень при проектуванні вибухових робіт на шахтах в майбутньому.Цель. Оценка гранулометрического состава горной породы с использованием системы создания изображений Microsoft. Методика. Были проведены пять взрывных испытаний в полевых условиях гранитного карьера для подтверждения эффективности данного метода гранулометрического анализа и изучения влияния линии наименьшего сопротивления (ЛНС), расстояния между шпурами и определенного заряда на степень дробления. Гранулометрический анализ цифрового изображения породы и щебня с использованием сервиса Microsoft произведен с учетом технических характеристик камеры, которые позволяют определять размер кусков. Результаты. Распределение размеров частиц, полученное при помощи анализа изображений Microsoft, показывает, что средний размер разлетевшихся частиц равен 0.60, 0.57, 0.43, 0.39 и 0.55 м, при этом средний размер крупных обломков равен 1.15, 1.07, 0.97, 0.8 и 1.02 м для 1, 2, 3, 4 и 5 взрыва соответственно. Определено, что при первом взрыве были получены самые крупные обломки размером 1.15 м, немного меньшие – во время третьего взрыва, и наименьшие – во время четвертого взрыва. Результаты испытаний свидетельствуют, что при увеличении ЛНС и расстояния между шпурами средний размер разлетевшихся частиц и средний размер крупных обломков увеличивается, и уменьшается при увеличении отдельно взятого заряда. Научная новизна. Дана оценка гранулометрического состава взорванной породы с использованием сервиса Microsoft и установлено, что метод сопоставим с гранулометрическим анализом, выполненным при помощи Wipfrag, Blastfrag, Fragscan, Powersieve, и характеризуется достаточной достоверностью. Практическая значимость. Система создания изображений Microsoft может быть использована как инструмент гранулометрического анализа. Результаты гранулометрического анализа будут способствовать принятию более эффективных решений при проектировании взрывных работ на шахтах в будущем.The authors appreciate staff and management of ZIBO-FM quarry, Akure, Ondo state, Nigeria, for their cooperation during data collection for this research

INVESTIGATION OF THE SPATIAL VARIABILITY IN OYO-IWA LIMESTONE DEPOSIT FOR QUALITY CONTROL

The continuing expansion of Nigeria construction industries coupled with the large importation of cement despite huge limestone deposits scattered all over the country is of great concern. This study investigates the spatial variability of Oyo- Iwa limestone deposit using the cement raw materials variables (such as Calcite) as well as cement quality parameters (Lime Standard, Silica Modulus and Alumina Modulus). In order to achieve this objective, exploratory borehole data were obtained, processed and analysed to examine the spatial pattern of the selected variables within the deposit. Statistical studies indicated that all the variables used in this research came from the same parent population. Due to skewness of the plotted histograms of the variables, normal transformation was applied to the variables. Also, the correlation matrix obtained showed that the considered variables shared low correlation with each other. The omni-directional variogram of each of the limestone variables were later constructed and systematically fitted both in the vertical and horizontal planes. Moreover, the directional variograms were also developed and this show neither severe geometric nor strong zonal anisotropy exist in the limestone deposit. The models were verified through cross validation and proved to be valid with the variance of the standard error, varying from 0.9796 to 1.0250 between the estimated and real data of the limestone variables. Also, the mean of the standard error of the cross validation varies from -0.0079 to 0.0336.The result of this research work will be informative and beneficial especially in the characterisation with modelling as well as reserve estimation of Oyo-Iwa limestone deposit

A comparative study of geometric and geostatistical methods for qualitative reserve estimation of limestone deposit

Abstract Mining projects especially relating to limestone deposits require an accurate knowledge of tonnage and grade, for both short and long-term planning. This is often difficult to establish as detailed exploration operations, which are required to get the accurate description of the deposit, are costly and time consuming. Geologists and mining engineers usually make use of geometric and geostatistical methods, for estimating the tonnage and grade of ore reserves. However, explicit assessments into the differences between these methods have not been reported in literature. To bridge this research gap, a comparative study is carried out to compare the qualitative reserve of Oyo-Iwa limestone deposit located in Nigeria, using geometric and geostatistical methods. The geometric method computes the reserve of the limestone deposit as 74,536,820 ​t (mean calcite, CaO grade ​= ​52.15) and 99,674,793 ​t (mean calcite, CaO grade ​= ​52.32), for the Northern and Southern zones of the deposit, respectively. On the other hand, the geostatistical method calculates the reserve as 81,626,729.65 ​t (mean calcite, CaO grade ​= ​53.36) and 100,098,697.46 ​t (mean calcite, CaO grade ​= ​52.96), for the two zones, respectively. The small relative difference in tonnage estimation between the two methods (i.e., 9.51% and 0.43%), proves that the geometric method is effective for tonnage estimation. In contrast, the relative difference in grade estimation between the two methods (i.e., 2.32% and 1.26%) is not negligible, and could be crucial in maintaining the profitability of the project. The geostatistical method is, therefore, more suitable, reliable and preferable for grade estimation, since it involves the use of spatial modelling and cross-validated interpolation. In addition, the geostatistical method is used to produce quality maps and three-dimensional (3-D) perspective view of the limestone deposit. The quality maps and 3-D view of the limestone deposit reveal the variability of the limestone grade within the deposit, and it is useful for operational management of the limestone raw materials. The qualitative mapping of the limestone deposit is key to effective production scheduling and accurate projection of raw materials for cement production