DRILLING AND LOADING
below OEM operating maximums to prevent overextending the drill’ s capabilities and causing damage or premature wear to the machine and ground engaging tools. Fully Autonomous utilises the same Dynamic Hole Quality Algorithm as One-Touch but allows one operator to run up to four drills from a remote Command Centre. Unlike remote control that requires full operator intervention for each drill, ARDVARC Fully Autonomous allows the drill operator to enter a drilling plan into the system to include hole collar coordinates, the order in which the holes are drilled, and bottom hole elevation. The drill will execute the plan without operator intervention. Haz-Cam Object Detection technology prevents collisions with persons or equipment working in the area and disables the drill if the hazard zone is breached.
Finally, the Multi-Pass Option allows for the semi-autonomous changing of steels. It is available for One-Touch and Fully Autonomous. Once the end of a steel is reached, ARDVARC runs a step-by-step process of the assembly or breakdown of additional drill steel.
Machine Health Data collected by ARDVARC shows information on 28 monitored systems on the drill.
The paper also included a case study from an open pit iron ore mine that produces approximately 44.9 Mt of ore annually with a stripping ratio of 3.5 t of waste per tonne of ore. The dominant ore body is haematite with a specific gravity of 3.25 g / cc and compressive strength of 40,000 psi.
The mine drills a 9 7 / 8” hole on a typical 20 x 21 pattern to a bench height of 41 ft. Their drill fleet consists of six diesel powered Cat 6420C machines. Automation of their drill fleet began in June 2015 with the installation of a One-Touch style system on one drill to test the efficacy of the technology. Two more drills were added in August 2015, one in September 2015, and the final two in November 2015. The mine is in the process of implementing fully autonomous drilling for the entire fleet.
The percentage of holes drilled using automation has increased over time as operators are trained and gain confidence in the technology. By the end of the study period, 85 % of the holes were drilled using automation.
Productivity is an average measure of various efficiencies whose inputs include mechanical availability and the actual drilling activities of the machine. The mechanical availability of this fleet was between 85 % and 90 % through the last few months of study data. The individual drilling activities analysed were: a) Drill Accuracy – Planned Hole Location X, Y, and Z versus Actual Drilled Location b) Penetration Rate c) Drill Metres per Month d) Number of Holes Drilled Per Month e) Drill Productivity f) Tonnage and Feet Drilled Plan vs. Actual
“ Probably one of the more interesting changes in drilling activity using automation is how the entire fleet’ s performance becomes uniform with very little variation. This offers tremendous advantages in planning and forecasting.”
Accuracy of drill hole placement is measured on three planes – X axis( burden), Y axis( spacing), and Z axis( bottom hole elevation / depth). At this operation, surveyors mark the collar locations prior to drilling. The drillers tram the machine using a targeting device on their One Touch System to align the drill over the hole. When the drill bit contacts the ground the system records the elevation and coordinates of the collar. Comparing the surveyed coordinates pre-drilling and the actual drilled coordinates illustrates drilling accuracy.
Prior to automation of the fleet anywhere from 10 % to as high as 30 % of the holes were“ out of spec” – meaning off by at least one hole diameter in one or all of the three planes. The introduction of automation saw more than 90 % of the holes being on plan in the last three months of the study period.
Hole to hole penetration rates show the metres drilled / hole over the drill cycle time. The drill cycle time includes time to tram to the hole collar, level the drill, collaring the hole, drilling the hole, retracting the drill string, retracting the jacks, and beginning the move to the next hole. At the start of implementation, the average drill cycle penetration rate was approximately 13 m / hour. The level after automation averaged 17.76 m per hour, an increase of 27 %.
“ For costing purposes, most mine operations typically assign an operating cost against some measure of machine productivity, such as the number of metres drilled. By this measure in the last six months as the utilisation of automated drilling increased by approximately 18 %, the metres drilled increased by 46 %.”
The productivity of a drill is measured as the average drilling time per hole versus the available drilling hours. The baseline for this mine prior to automation was 40 % and the data suggests that four of the drills are maintaining a pretty consistent level of productivity well above this, while two are lagging behind the rest of the fleet due to downtime issues. The productivity rate as a fleet has increased by over 50 % since automation was implemented.
Introducing the Joy P & H 77XD
Responding to customer requests for versatility in surface drilling, Joy Global in 2016 introduced its P & H 77XD blasthole drill, which can be configured for rotary or hammer drilling, diesel or electric power, and single- or multi-pass drilling.
The new Joy P & H 77XD is compatible with Joy Global’ s new high-precision GPS tele-remote operation console and automation solution
This new machine, which debuted at MINExpo 2016,“ is designed to deliver an up to 10 % maintenance and repair cost advantage, and an up to 5 % availability advantage. The drill’ s name reflects its 77,000 lbs of max bit loading capacity.”
Following its debut, the first machine was shipped to operate at Kinross Gold Corporation’ s Bald Mountain gold mine in Nevada. With a focus on solving today’ s toughest mining challenges, Joy Global equipped the first of its next generation of P & H drills with features to help extend equipment life, reduce costs and improve safety, including: n Robust solid boxer style mast construction with a simple rack and pinion pulldown design to reduce maintenance effort while increasing drilling forces n Innovative automatic bit handling and pipe handling functions to improve safety and increase machine utilisation n Intelligent compressor control, which manages power consumption and associated bailing velocity, to lower operating costs Several other smart features are available for the drill to facilitate improved cycle times, including enhanced auto drill and electronic load sense control. The 77XD is compatible with Joy Global’ s new high-precision GPS tele-remote operation console and automation solution, which includes features such as geo fencing, auto navigation, auto level, auto drill, obstacle detection and mitigation, Hawkeye 360 ° camera system, and more.
Joy Global states:“ Drill automation features help our customers improve drill utilisation. Higher utilisation leads to additional holes drilled, higher production rates and, ultimately, greater potential customer revenue.”
In more detail, the automation solution is
60 International Mining | APRIL 2017