Grade control geological mapping in underground gold vein operations article pdf available in applied earth science imm transactions section b 1212. The drilling will be conducted on a 25m x 25m grid. Notice how a steepening penetration curve decreases the number of drilling days. Grade control for dozers trimble civil engineering and. A total of 21 air core drill holes are planned over altechs 100%owned tenement e703923, which is located approximately km east from perth, western australia. The asymmetry of the leading edge creates a steering bias while the nonrotating aspect of the drill string allows the steering bias to be held in. A dedicated team of grade control operators undertake blast hole sampling, spot grade perimeters in the openpit and control loading and dumping of material to and from low, medium and highgrade ore stockpile destinations. Use a single laser and laser receiver to measure the lift and tilt of the blade. Downhole surveys with multishot electronic or gyro surveying when drilling both straight and deviated holes, the position of the wellbore beneath the surface must be determined as the well is. During exploration, grade control is a mining process to quality check and control the grade and variability of an ore. Optimisation grade control procedures at the open pit. Optimisation of the grade control procedures at the yandi.
Interaction with other heavy equipment and site specific safety requirements are considered in swps and competent staff ensure safety and cohesion. Makabingui gold project as previously reported, phase 1. Underground mining focus with major rc drilling campaign at was cannon gold mine. The grade control drilling targeted the near surface portion of the modelled mineralisation as defined by the broad spaced resource definition drilling. Figure 3 shows the experience of exco resources in the haynesville shale over time and graphically illustrates a progression of improving efficiency in drilling days days to depth. Optimal grade control sampling practice in openpit. Any inaccuracies at this stage can cause major setbacks to operational and business performance. The planned infrastructure includes 143km of rail and a 30mtpa dry ore processing. Conventional blasthole sampling for grade control has acquired an extremely bad reputation for the last 50 years. Machine control trimble civil engineering and construction. In fact, it can produce the opposite effect, significantly increasing the. The most economical method to carry out grade control is reverse circulation drilling for mineral grade control. This is a dedicated grade control rig that when possible also drills piezometers and water wells. In some mining operations, one of the most important roles played by the geologist is the supervision of grade control.
Pilot hole directional drilling pilot hole directional control is achieved by using a nonrotating drill string with an asymmetrical leading edge. Integrating the theory of sampling into underground mine. The grade control data must be available in time to inform and be integrated into the mining plan if it does not do that, it is too late. Dominy synopsis geologists in some underground gold mines collect grab samples from broken ore piles or trucks as a method of grade control. Prior to mining the ore bodies, wallis drilling operate a fleet of tracked and wheeled grade control rigs including atlas copco l8 rigs, sandvik dr580 and. During this time frame, the driller starts actually drilling the well and the supervisor level 4 candidate is actually out of the simulator room. As expected, the openpit mining operations will shortly be accessing the higher grade part of the ore body. Blasthole sampling for grade control the many problems.
A plan view of the preblast ore control block model. Grab sampling for underground gold j mine grade control. Pdf underground reverse circulation grade control drilling in a. The grade control drilling program is designed to be suited to the style of mineralization and ore shape complexity. Our fleet is truck and track mounted dependant on the application. The grade control drilling will also allow the practical application of potential selective mining and high grading strategies in the first four years of production. Gain a competitive edge and streamline your operations with the next generation of grade control systems from trimble, the company that invented grade control. Mine geology, grade control, and reconciliation srk. Eliwana project package 751ewc0001 grade control reverse circulation drilling scope of works 751ewc0000tead0001 eliwana project. Trimble offers a complete line of grade control systemsfrom laser or sonicbased through to 3d, these rugged systems are easy to use, fully upgradeable and flexible enough to meet a wide range of application and jobsite requirements. Asx atc commences grade control drilling at meckering. The programme was designed to define the grade distribution to be exploited in the first stage of open cut mining approximately 20m vertical and concentrated on the.
A consistent record of poor reconciliation is an indication that this variance has not been adequately managed. The first 40 minutes or so of the exam was going over the instructions to the driller as well taking the slow pump rates spr and choke line friction clf values. Rc rigs used open pit production grade control geology. We have a progradex sampling system and a blowdown valve for wet drilling rod changes to keep the samples dry.
Grade control programs aim to deliver economic tonnes to the mill via accurate definition of ore and waste. Sample quality and productivity are paramount to any grade control operation. Pdf improved grade control using reverse circulation drilling at. Carswell and others published underground reverse circulation grade control drilling in a high nugget gold deposit.
Ranger have a fleet of rc grade control drill rigs suited to multiple commodities and operations. Fmg solomon is developing a new mine and associated infrastructure at its eliwana site eliwana project. In practical terms, the answer will relate to the vertical rate of advance of mining, overall pit geometry and the grade controlmine planning cycle time. However, the total costs for rc drill sampling are significantly more than for manual bh sampling. Pdf grade control geological mapping in underground gold. Castle drilling company has extensive experience in open pit grade control drilling situations, drilling infill holes accurately at high rates of production without compromising sample quality. At present, pit sampling employs ditchwitching, blast holes, and inclined rc and percussion drilling, depend ing on the situation and cost. A 2d trimble gcs900 grade control system is an excellent first investment for contractors new to construction technology. Geodrill provides reverse circulation, diamond core, deep directional drilling, aircore, grade control, geotech and water borehole drilling services to major, intermediate and junior mining companies and operates the largest most modern fleet of multipurpose rigs on the african continent. Once a face or stockpile sample is collected, the operation has already spent money and committed to develop infrastructure and development. Pdf grade control practices at the big gossan stope mine. Spotlight ongradecontrol theaustralian institute ofgeoscientists aigheld theirfifthsuccessiveannualseminaratobservationcity, scarborough, inperthon15thnovember,1990. Grade control systems allow machinery to operate at a continuous pace, rather than having to stop for a grade checker to come and measure the excavation, as with conventional equipment a process that often needs reworking. Underground sampling methods include linear chip and channel, grab broken rock, and drillbased samples.
Grade control is critical to practical excavation plans. New exploration rig from atlas copco makes grade control. Statistics of the ore control block model ore type cutoff gt. Such improvement may be leveraged from existing resource drilling data which are typically less numerous but better quality than the grade control data. Drilling designed to extend high grade 5gt au continuity over a 100m interval below the open pit. Grade control drilling program commenced at the 100% owned boorara gold project, 10km east of kalgoorlieboulder in the western australian goldfields program comprises 18,000m of drilling at the regal, royal and crown jewel lodes on an average 10m by 5m drill pattern to a maximum depth of 60m. Optimizing gradecontrol drillhole spacing with conditional. Searching for world class high grade gold and silver. Mine geology, grade control, and reconciliation optimize mine planning and profitability by understanding the geological controls on orebodies an appreciation of the geological spatial controls to mineralization is fundamental to mine operation optimization, nearmine exploration, resource estimation, geotechnical engineering, and mineral. Appropriate drilling methods rab early exploration first pass and infill drilling rc intermediate exploration delineate ore body grade control diamond late stage structural controls.
Reverse circulation is the most commonly used drilling method for grade control in open pit mining operations. The grade control process a complex system is in place that is capable of a high degree of control and selectivity. Grade control is an important value add to any ore reserve. The similarities and differences of the procedures are first discussed in the light of an example. The foundation of a successful program is high quality sampling supported by geology and.
They are usually excluded from grade control estimates termed the base case approach here because of the differences in quality. Integrating the theory of sampling into underground mine grade. Grade control drilling grade control in mining ranger. It was estimated by the difference between actually used blast hole sampling protocol and its optimized version. The essence of ore grade reconciliation is to identify, analyse and manage variance between planned and actual results in a way that highlights opportunities. Rc grade control drilling open pit rccq drilling open pit reverse circulation drilling rc and coal quality drilling is a specialised drilling technique were the drilled aggregate travels up through the centre of the drilling string and into a splitter box where samples can be collected and passed onto the laboratory for further assessment. The second round of grade control drilling has provided further strong confidence in the geological model being used for pennys find. In other cases, the decisions based on grade control samples are not critical. Black is very high grade ore vhg, dark grey is high grade hg, medium grey is medium grademg, and light grey is low grade lg ore type. The introduction of many sources of bias is a structural reality. Groundbreaking innovation at the forefront of local drilling company master drilling, a jselisted drilling solutions provider is advancing and developing in this evergrowing, everdiversifying landscape with its new, innovative technology a mechanised blind shaft boring system. Add another laser receiver or a slope sensor to measure the slope of the blade.
Grade control drilling affirms current resource model for. Grade control technology improves efficiency, increasing the productivity and profitability of an operation. Grade control is used to define the ore grades and ore blocks in the pit and also provide knowledge for mine planning and blasting. The grade control drilling program is to assist the company in planning its future meckering mining. How to pass the iwcf supervisor well control exam the. Utilising the same techniques as reverse circulation drilling, grade control drilling is done at shallow depths and with close drill patterns to map out the ore reserves. This would inevitably result in significant economic impact on mining companies. The initial grade control drilling intercepts included high grade gold intercepts including 102 grams per tonne gold gpt over 1. Get elevation and slope guidance to get to grade quickly and. Weighting biases aggravate an already bad situation. Optimal grade control sampling practice in openpit mining a full. Any proven application of these strategies is expected to lead to further improvements in the.
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