FRAGMENTATION
Graph showing fragmentation results using Dyno Nobel fragmentation model
also noted that the tighter the joint spacing, the finer the overall fragmentation. Additional fragmentation modelling can be employed to continue the refinement for the basalt, but also for the other geological formations. Continued analysis will lead to the optimised blast design for this operation.
EPC assesses blaststs with drones
The Redbird Cloud platform is already being used to host the EPC Premium blasting module developed in partnership between Redbird and the EPC Group. Users include quarrying group Carrières de la Vallée Heureuse( CVH), in Rinxent, in the Nord-Pas-de-Calais. The operator is a long time user of Frontir, EPC’ s blasting plan design software, which it uses because of the multiplicity of its faces with varied chemical quality. In order to save time, it has started to replace a 3D laser for surveying a face with a drone. A drone is also used to overfly completed blasting areas to assess the spread and the block size distribution. Once compiled, all the data can be exported to EPC Premium to help CVH to design safer blasting plans, thus reducing the risks of flying rocks.
In its Marquise quarrying district, between Boulogne-sur-Mer and Calais, CVH has started to use a drone for face surveys. Its objective is to work with drone data captured locally for locating blasted areas using the Frontir software developed by the EPC Group. Photographs taken of the face give the precise location of areas of land or karst, which improves the overall design of the blasting plan.
Another use of the drone, tested in the quarry, is filming the blasted heap and comparing the data obtained with that used to locate the blasting in the Frontir software, in order to view the blasted heap in 3D and understand how the blasting went. The interest is in obtaining profiles
of the shape of the heap, and to view the lines of holes by line of holes while comparing them with the starting massif. This makes it possible to calculate the separation, heap height and length parameters.
All this information is sent over the Redbird Cloud platform and may be accessed from the EPC Premium module. This data, like that for a blast, will be available so that the operator can rate a blast and monitor its settings.
Frontir gives geometric information to visualise in colour critical shading, areas that correspond to the distance to the nearest hole. Once the bench is drilled, it is up to the operator to adjust the charging plan originally planned due to holes that have not been drilled deeply enough or angles that have not been respected. This information will be sent to the Redbird Cloud platform as well. It is of use to the operator and CVH ' s in-house blasting team responsible for checking the quality of the layout, because the first criterion of quality is distribution of the material between the holes.
Based on the distribution, the Chief Blasting Officer then adapts the charging plan: this plan, displayed on screen, shows the theoretical volumes on which the explosives for each hole will act, with the energy distribution for each volume. According to the massif and the parameters determined by EPC, the software helps to determine the necessary energy( megajoules / m 3) to accomplish the desired block size. The software shows whether there are geometric disparities in volume that could cause a poor spread, blocks, production delays, vertical projections, etc.
Since drones have been used, the operator can generate a 3D blasting plan on a photogrammetric model. By opening Frontir, it has access to a georeferenced drone template( the ground targets have been measured by centimetre-accurate GPS). This 3D model is positioned absolutely in the coordinates of the quarry ' s georeference system. With this data, the procedure for laying out a blast is the same as that previously conducted with a laser scanner, but this time in front of a computer screen and no longer opposite the face. On the screen, the user has the impression of being inside the quarry, such is the precision of the image definition.
Each blast is exported to the Redbird Cardinal platform, in the blasting module – EPC Premium – with marking of all blasts carried out. By selecting a blast, a window will appear with different tabs giving the explosive consumption, the charging plan, and the distribution of volumes and results, including performance indicators used to establish statistics over an area of the quarry, over a series of blasts, or over a given period.
According to Ricardo Chavez, the EPC Group ' s Technical Director,“ ultimately it will be possible to centralise data on vibration emissions related to each blasting, as well as on complaints from residents, to observe breaches of emission thresholds, to know the carbon footprint of each blasting, the distribution of thicknesses to calculate the location, drilled lengths, quantities of explosives, etc.” The operator will be able to track this data and will have the opportunity to quantify improvement of the results and the impact on the production line.
The great advantage that the drone provides when overflying a blast is safety; the remote operator is further away from the face than with a laser, and has access to inaccessible areas to monitor places that appear dangerous.
Using Frontir, soon it will suffice to press the button“ export to Redbird Cloud” to populate the platform, review the explosives and obtain performance indicators( BRH times, fine rates, block rates, projections, etc). The data will be centralised on a single server and used to compile statistics over a period to see trends in the fine rate or vibration rate.“ The tool will give quantified data to something that hitherto was merely felt”, says EPC.
Redbird, Airware and Caterpillar
Redbird is now part of US drone services giant Airware, as of September 2016. Airware provides end-to-end solutions that turn aerial data into actionable business intelligence for enterprises, and announced in early February that it has secured a strategic investment from Caterpillar Ventures. The investment allows Airware to accelerate programs that enable dealers to offer solutions and services within the construction, mining, and quarrying industries,“ and highlights Caterpillar’ s commitment in leading the Industrial Internet of Things( IIoT).”
“ This investment is a continuation of Caterpillar’ s commitment to help our customers be more productive and make improved business decisions,” said George Taylor, Caterpillar Chief Marketing Officer & Vice President of the Marketing
16 International Mining | MARCH 2017