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By Lifeng Li, Jhon Silva-Castro

In a previous work, the authors analyzed the overlapping probability of two adjacent charges in a single hole for pyrotechnic and electronic detonators. This document extends such work to a complete mine blast where more than two holes are detonated. In a mine blast, all the blast holes are connected as a network by detonators to follow a given initiation sequence. Such initiation sequence’s performance is based on the adequate timing between charges in the mine blast. The analysis of the reliability of a mine blast based on the timing between charges and the initiation type is presented in this document. For a long-run time and under proposed operating conditions, the reliability of the mine blast can be analyzed based on the network which is treated as a system. The failure of the system is defined as no success between any two delays charges either in a single hole or in between two holes.

Jan 1, 2016

By Alejandro Ferrada Vergara

Most blasting techniques that are designed to improve fragmentation and subsequently improve ore work index to downstream comminution processes, apply powder or energy factor increases, either by stretching the drilling pattern (burden/spacing ratio) implementing faster initiation sequences or using more energetic explosives. The new application will move detonation parameters up, making the blasting process riskier for the surrounding boreholes, explosive column or initiation systems functioning.

Jan 1, 2016

By Peter Richards, Alexander Lewis-Gray, Mark Davies, Nicholas Katsikaros

"Gekko Systems developed the Gekko Resin Exchange Column (G-REX) in order to optimise the recovery of gold in complex leach-to-electrowinning processes, as an intermediate step using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin (Lewis-Gray et al, 2015). Operational experience has been gained at the CGT Ballarat Gold Plant in near continuous operation since 2008, treating unclarified concentrate leach solution. The extension of the technology to higher throughputs and more complex chemistry is discussed.Aurix®100 ResinAuRIX®100 resin is a cross-linked polystyrene alkaline resin developed by Henkel (Virnig et al, 1996). The resin beads are off-white in colour, spherical, with a nominal size of 100% +600µm. This resin is highly selective for gold and silver over many metals, by way of extracting precious metal cyanide complexes from leach solutions with a pH less than 11.5. The higher end of the pH scale produces best selectivity according to the order of preference: Au > Ag > Hg > Zn > Ni > Cu > Co > Fe. Purolite produces the resin and Gekko Systems maintains licensing of AuRIX®100 resin for use in its G-REX column as part of its unique suite of gravity gold handling equipment.Significant cost savings over carbon-in-solution (CIS) systems are realised with AURIX®100 resin, of around 4% to 12% in capital savings and 27% to 40% in operating costs (Virnig et al, 2004). Allied to this is that AuRIX®100 resin is not susceptible to fouling, that is, the resin does not load with inorganic salts or organic compounds which would affect the loading and extraction of precious metals. To counter any potential for fouling by inorganic salts, in service a dilute acid wash is carried out periodically on the resin to unblock resin pores."

Jan 1, 2016

By J. N. Van der Merwe, M. Mathey

"The South African squat coal pillar strength formula, developed by researchers from the Chamber of Mines Research Organization in the 1980s, predicts an exponential increase in coal pillar strength once a critical width-to-height ratio of 5 is exceeded. The arguments that have been proposed in favour of this formula are discussed critically in this paper.Field experience with squat pillars in the USA and evidence from published physical, analytical, and numerical model pillar studies corroborate the fact that a squat effect is unlikely to occur in coal pillars at width-to-height ratios less than 10. Furthermore, an exponential increase in peak strength of coal pillars does not exist. An alternative design criterion for squat pillars in South Africa is therefore suggested. IntroductionFive decades of coal pillar research in South Africa have produced a wealth of information on the mechanisms contributing to the strength and failure of in-situ coal pillars and accompanying phenomena. The relevant knowledge was sourced from, and for, a South African coal mining environment that remained largely unchanged in the second half of the 20th century. The depth of mining seldom exceeded 250 m, with mined seam thicknesses averaging 3 m and typical pillar width-to-height ratios (w/h) of 3–4.It is therefore not surprising that comparatively little research has been directed at the prediction of coal pillar performance in deeper deposits, where squat pillars of larger width-to-height ratios will be required to support the overlying strata. However, a thorough understanding of squat pillar performance will be necessary should the remaining deep coal deposits of the country be extracted in future, for instance in the Waterberg or Ermelo coalfields.A squat coal pillar strength formula has already been proposed in South Africa. The origin of this formula will be discussed in some detail in the following sections and its appropriateness will be critically reviewed against a great amount of evidence from relevant squat coal pillar research conducted internationally."

Jan 1, 2016

By M. Soleymani Shishvan

"Continuous mining systems containing multiple excavators producing multiple products of raw materials are highly complex, exhibiting strong interdependency between constituents. Furthermore, random variables govern the system, which causes uncertainty in the supply of raw materials: uncertainty in knowledge about the reserve, the quantity demanded by the customers, and the breakdown of equipment. This paper presents a stochastic-based mine process simulator capturing different sources of uncertainties. It aims to quantify the effect of geological uncertainty and its impacts on the ability to deliver contractually defined quantities and qualities of coal, and on the system efficiency in terms of utilization of major equipment. Two different areas of research are combined: geostatistical simulation for capturing geological uncertainty, and stochastic process simulation to predict the performance and reliability of a large continuous mining system.The process of modelling and simulation in this specific production environment is discussed in detail. Problem specification and a new integrated simulation approach are presented. A case study in a large coal mine is used to demonstrate the impacts and evaluate the results in terms of reaching optimal production control decisions to increase average equipment utilization and control coal quality and quantity. The new approach is expected to lead to more robust decisions, improved efficiencies, and better coal quality management.IntroductionContinuous coal mining systems containing multiple excavators producing multiple products of raw materials are highly complex and exhibit strong interdependencies between constituents. A network of conveyor belts is used for transportation of the extracted materials to different waste dumps or the coal stockpile.Optimal decision-making in short-term planning and production control are impacted mainly by geological uncertainty associated with incomplete knowledge of the coal deposit represented in the reserve block model. These uncertainties cause deviations from expected process performance. For more robust decision-making, understanding the impacts of these stochastic elements plays a key role."

Jan 1, 2016

By Jun Yang, Zongshan Zou, Mei Qu, Jianjun Zuo

For technical renovation of the thermal plant, one frame structure workshop of 50,000 m2 (59,800 yd2) construction area and one reinforcement concrete chimney of 150m (492 ft) height shall be demolished by blasting at same time. The engineering environment of which is complicated and the accommodation space is limited. Therefore, the collapse sequence, direction, scope of the dismantled building must be accurately controlled to ensure the safe operation of the adjacent generator unit and transformer station. By taking technical measures of theoretical analysis and numerical simulation etc., as well as research on structures collapse method and detailed delay interval, it puts forward the technology of bidirectional folded collapse of the workshop and it uniquely adopts the initiation system that combined with “half-second delay inside drilling” and “millisecond delay outside drilling”. Additionally, by using of the integrated vibration reduction technology in combination of the blasting ruins, buffer ditch and damping ditch, it has safely accomplished the demolition blasting work in high efficiency. Besides the demolition blasting vibration signal is collected and analyzed. The success of the demolition blasting will become valuable reference to other similar works.

Jan 1, 2016

By Yan Germain, Université Laval, Bernard Dallaire, Jocelyn Bouchard, Peter Radziszewski, Gilles LeBlanc, Michelle Levesque, Nicolas Tremblay

"The comminution process is estimated to be only 1% efficient, resulting in waste energy dissipated as heat, noise, and vibration. Energy recovery from grinding circuits has not been implemented mainly because recovering heat from the surface of the grinding mill or from mill slurry can impede operation, increase maintenance requirements, and prolong plant shutdown time (and production). However, currently very little information is available in the public domain regarding the amount of waste energy and that potentially recoverable in the grinding circuit of a mineral processing plant. Availability of such information could drive innovation and improve decision-making regarding opportunities for waste energy recovery. The Canadian Mining Innovation Council (CMIC) has initiated a study with CanmetMINING and mining industry partners to develop a model to map the energy flows in grinding circuits and to quantify the potential for energy recovery. The paper outlines the underlying fundamentals and data requirements for use in the model and then focuses on quantifying the energy recovery potential of the semi-autogenous grinding and ball mill circuits at the Agnico Eagle Goldex Division. Results show that most of the electrical energy (over 75%) is used to heat the slurry, leaving only a relatively small amount of it to achieve mechanical work (~9%). INTRODUCTIONCanmetMINING commissioned a study in 2013 to better understand the barriers for adoption of new technologies in the mining industry (MNP, 2013). The conclusions highlighted the importance of enhancing industry/regulator engagement and communication to raise awareness and improve the industry’s comfort level with new technologies.In November 2014, the Green Mining Innovation Advisory Committee (GMIAC) held a workshop to explore the possibility of accelerating the uptake of green mining technologies by bringing together key stakeholders among the mining value chain to address industry priorities. Participants included representatives from mining companies and associations, academia, provincial governments and federal departments and organizations. Two key priority areas emerged at the workshop: i) energy saving, and ii) water management."

Jan 1, 2016

By Noelia Valencia, Carlos Agreda, Jean Arenales, Juan Llerena

"In this technical paper is reported the several tests and the preliminary results that has been obtained so far. It must be emphasized that this investigation was started several months ago.On the other hand, it is known that acid water exists in some underground mining operations as well as in open pit mining operations all over the world. Taking into account this problem, our work teamdecided to carry out the present investigation. Therefore, it ensures a decrease in blasting costs avoiding this problem and as well as this, it allows to reducing fatal accidents that could occur caused by poor control of acid waters within mining operations."

Jan 1, 2016

By P. M. Solozhenkin, O. I. Ibragimova, I. P. Solozhenkin

Molecular models of complexes of poorly studied bismuth, gold, and arsenic mineral clusters and reagents were created for use in collector activity forecasting using Chem Bio 3D and ChemOffice2005, with optimization by MM2. The density functional theory approach was used to determine HOMO, LUMO, SOMO, and total energies, atomic charges, and s, p, d- populations for various compounds. The structure-based virtual screening (SBVS) and docking technique was proposed to reduce the vast number of compounds to a more manageable number for selection of potential flotation candidates. The prognosis of collector activity evaluation (PCAE) strategy was proposed as a consistent approach to estimate the interaction between a collector and a mineral cluster as the difference between the total energy and sum of cluster energy and collector energy to search the analogue of butyl xanthate. The negative relationship between PCAE and flotability was shown. The combinations of dialkylamino sulfhydryl collectors can be considered as prospective reagents for gold-bearing sulfide ore flotation. These results were confirmed by experimental data in ore flotation. The increase in recovery of gold and bismuth with the aid of a combination of reagents has been established and additional cyanidation of tailings has been avoided.

Jan 1, 2016

By Chulgi Suk, Hoon Park, Hyonsoo Kim, Hakman Kim, Sangho Cho

Dust emission from blast demolition and other construction activities can be a nuisance; it is widely recognized that fine particles less than 10 µm in equivalent diameter (called PM10) may cause health problems. Mist spray systems, such as rain guns, sprinklers, water/surfactant sprays (or foams) etc., are some of the most effective dust suppression methods. A large amount of research has showed that when water droplets are produced in an equal amount to that of dust particles, the airborne dust is suppressed by the agglomeration of dust and mist particles. A method for generating micro-sized mist from water, achieved by the detonation of explosives in the water tube, was suggested and is called the ‘detonationdriven water bag burst system’. There are many experimentally observed limitations of the explosioninduced water break-up process. The water bag explosion tests were simulated using the AUTODYN software, in order to investigate the aerosolization mechanisms of the detonation-driven water and water break-up process into micron-sized droplets. As a result of the numerical analyses, the diffusion direction of water when detonating in the central interior part of water tube was radioactive and significantly stronger than when detonating in the bottom exterior part; this is due to the compressive flow of the volume change inside of the water tube, which resulted from the blasting wave inside of the tube, as well as the reflected pressure on the ground. Blast tests of full-scaled reinforced concrete columns were conducted to verify the effectiveness of the suggested detonation-driven water bag burst system. The water breakdown and dispersion that occurred while blasting the reinforced concrete columns were observed using a high-speed camera, and dust generation was monitored using four density detectors. The suggested detonation-driven water bag burst system showed that the average dust density decreased by up to 7 mg/m3.

Jan 1, 2016

By Ewan Selers, Gary Cavanough

Drilling automation technology is well advanced and automated drill rigs are in use at a number of operating mines. This is not the case for the other drill and blast processes due to significant technical challenges to overcome. These challenges, with regard to the current “on bench” practices, include placing the initiators, loading the explosive and connecting up the initiation system. Although difficult, these challenges will be solved with engineering advances.

Jan 1, 2016

By L. Cáceres, G. Leinenweber, P. Bustamante

"Given the severe scarcity of fresh water sources in Northern Chile the use of seawater has become the only alternative to allow mining expansion. This option however poses several technological challenges as a result of the high concentration of natural salts that promote various forms of metal corrosion. Therefore the steel piping protection has been a constant challenge for design engineers responsible for solving the problems of corrosion. Known protection alternatives are varied and expensive, a few of them are rubber coatings, protection based centrifuged concrete, extra wall thickness of pipes in combination with corrosion inhibitors, extra wall thickness of pipes without using corrosion inhibitors, and the use of highly corrosion resistant steel materials.In this framework the aim was to study the corrosion kinetics of carbon steel pipe API 5L X70 under electrochemical and weight loss testing. The test conditions include a range of seawater velocities between 0.2 to 3.0 m/s.For electrochemical experiments the API 5L X70 steel specimen was a 4 mm diameter disk embedded in an 8 mm diameter Teflon rod and exposed to seawater. Duplicated coupons were placed in a standard test apparatus that was built according to the standard ASTM D 2688 – 94.The main results were: a) corrosion mechanism explained in terms of the counterparts partial processes which are the hydrogen evolution and oxygen reduction reaction; b) for the test specimen a corrosion band like feature that suggest a lateral dispersion of aggressive solutions from corrosion pits; c) a range of corrosion rates between 1 and 1.96 mm/year for flow rates between 0.2 and 3.0 m/s; and d) a convenient inhibitor dose between 20–25 mg/L for optimum inhibition efficiency to obtain a maximum value of 80% for corrosion efficiency."

Jan 1, 2016

"A fire design innovation of the concrete lining of the Ohio River Bridges East End Crossing Tunnel has been developed. As a result from a fire suppression and tunnel ventilation system, the project design Heat Release Rate (HRR) was able to be constrained from 300 MW to about 50 MW. With this reduced HRR, concrete lining without passive fire protection may be acceptable, if the tunnel concrete lining will not result in explosive spalling during the designed fire event. Concrete explosive spalling test was proposed to verify this assumption. Since no standard concrete fire explosive spalling testing procedure exists, a project specific testing procedure was developed and fire tests conducted. From fire test results, it is concluded that the proposed tunnel concrete lining, in conjunction with the proposed fire suppressing and ventilation system, will not experience explosive spalling and does not require a passive fire protection system. INTRODUCTION The Ohio River Bridge East End Crossing Tunnel is part of a Public Private Partnership project, which connects transportation network between Louisville, Kentucky and southern Indiana. Located in Louisville, Kentucky, the twin-tube highway tunnel provides northbound and southbound lanes of the Kentucky approach to a new bridge across the Ohio River. Tunnel lengths are approximately 1,675-ft and 1,685 for the northbound tube and the southbound tube, respectively. Connected by two cross-passages, both tubes have a roadway width of 40-ft, for 3-lane traffic, and a vertical clearance of 26.5-ft.The Tunnel was constructed by drill and blast method with shotcrete and rock dowels as initial ground supports. The final tunnel lining consists of 16 inches cast-in-place concrete lining and 20 inches invert slab, with a waterproofing system around the tunnel perimeter. Two (2) tunnel side drains and one (1) invert drain were provided for each tube. This paper describes the rational in assessing fire design requirements of the tunnel final concrete lining, to answer the question whether a passive fire protection system is needed or not."

Jan 1, 2016

By Cathy Aimone-Martin, Brent Meins

A comprehensive instrumentation program was implemented at the Howland Hook Marine Terminal on Staten Island, NY during proximate underwater rock blasting in 2014. Forty-two blasts took place over a 4-week period to deepen the 1200-ft (366 m) Berth 3 from -45 ft (-14 m) to -50 ft (-15 m) MLW to accommodate Post-Panamax vessels. Approximately 86,000 yd3 (65,752 m3) were blasted 120 to 9 ft (37 to 2.7 m) from the wharf to a total depth of -57 ft (-17.4 m). Pre-blast planning included developing and implementing a comprehensive monitoring plan and setting vibration and strain limits to protect the wharf. The plan outlined methods to measure vibrations on five corners of four concrete deck sections, on five concrete-filled pipe piles just below the pile cap near deck corners, and in bedrock adjacent to pile sockets. Water overpressures were measured near instrumented piles for 19 blasts closest to the wharf. A total of 19 geophones were secured to the wharf structure and buried 12 ft (3.7 m) in drilled holes.

Jan 1, 2016

To meet the energy requirements, hydroelectric projects are planned and executed in many countries. Though these projects requires a high capital investment, the returns are regular with minimum maintenance after commissioning of the project and are ecofriendly. Bhutan is situated in the eastern Himalayas and covers an area of 38,394km2 (14824.01sq. miles. It is bordered by India in East, South and West and by Tibet in the North. The hydropower potential of the country is estimated at 30,000MW, out of which around 5% has been harnessed.

Jan 1, 2016

By S. Bellec, P. Champagne, J. Châteauneuf, A. Berton, S. Fortier

"The start-up of new plants, extending from the commissioning of equipment to the production ramp-up, is a critical period where the processing circuit operation must be done in a structured and well controlled way to enable the gradual, safe and rapid achievement of production targets. The magnitude of the many risks associated with this pivotal period is accentuated in the actual context of low commodity prices. However, the implementation of a method that analyzes risks associated with a start-up, their probability of occurrence and their impacts leads to the identification of a series of preventive actions that can be applied in order to reduce potential negative impacts.Soutex has been involved in numerous start-ups over the last few years and has developed a structured methodology to assess this crucial period, maximize the pre-start-up preparation, ensure a smoother and safer ramp-up period and minimize the time needed before reaching commercial production.This paper describes a method to identify preventive actions to apply in order to reduce risks related to a plant start-up. Then, the various steps of the method are demonstrated using the industrial case study of the Canadian Malartic gold plant situated in Abitibi, Québec. The specific preventive actions, during start-up, the organisational measures and the ramp-up plan are detailed as they were effectively achieved. Finally, the post start-up actions are presented as well as some key results illustrating the achievement of their prior defined objectives.IntroductionPlanning a new plant or new circuit start-up in a mine installation involves various risks, both at the economical and safety levels. Unprepared staff and equipment can lead to safety issues that could threaten plant staff as well as the environment. Moreover, a poorly prepared start-up could often lead to equipment break-down, production stoppages and delays, leading to important economic impacts, delaying commercial production and therefore affecting directly the profitability of mining projects.It is common in the industry to have structured commissioning procedures for major equipment taken separately. Technical personnel from the equipment manufacturing company would usually come on site in order to perform the pre-operation verification, dry runs and the first hours of operations. This kind of assistance is usually focussed on one piece of equipment and neglects the interactions between the various equipment of the production chain. The commissioning phase is usually maintenance oriented and the information given by the manufacturing representative seldomly flows through the operation staff (in the case of this paper, the denomination “staff” refers to both managing and operating employees). The global process is usually not taken into consideration by the technical personnel sent on-site by the manufacturer during the commissioning phase. Many papers can be found describing the commissioning of new equipment focussing on the technology (Côté and Adante (2009), Wells et al (2007)) but without dealing with its integration process in the complete production chain."

Jan 1, 2016

By F. McCarthy, R. McDonald, G. Woodbridge, G. Brock, D. Robinson

"The Direct Nickel process is a hydrometallurgical technology being developed to treat nickel laterite ores by leaching at atmospheric pressure. The leaching process uses nitric acid in a relatively large excess, is thus non-selective, and much of the soluble iron goes into solution. The first stage of solution purification is iron hydrolysis and the Direct Nickel process utilises the colligative properties of the pregnant leach solution (PLS) to enable the removal nitric acid of varying concentrations via distillation. Once sufficient acid has been removed, the boiling point of the solution is increased allowing high temperatures (up to ~170°C) to be achieved under atmospheric pressure. The higher temperatures initiate the precipitation of the iron primarily as hematite and allow the removal of the acid generated by the hydrolysis reaction. The rejection of the iron is near complete with solution tenors typically falling from 65 g/L Fe, or more, to less than 50 mg/L Fe. The separation of clean nitric acid from the PLS at this stage allows for relatively simple acid recycling. A hematite product with iron content above 60% could also provide an extra revenue stream.INTRODUCTION The Direct Nickel (DNi) Process is a novel hydrometallurgical processing route designed to treat all types of nickel laterite ores in a single flow sheet using nitric acid under atmospheric conditions. A simplified flow sheet is shown in Figure 1.Between 2007 and 2012 the process was developed and refined at Direct Nickel’s laboratory within the CSIRO Minerals’ facilities in Perth, Australia, and in 2013 a series of pilot plant trials were run under continuous operating conditions. The process is designed to treat both limonite and saprolite in the same flow sheet, and after comminution, the blended ore is mixed with nitric acid and leached just below boiling point in agitated atmospheric leach tanks. The acid is added in excess, so typically for a blend of limonite and saprolite the acid addition can be in the order of 1.8-2.0 t acid/t dry ore. After a residence time of between 4-6 hours the majority of the soluble metals have leached into solution and the insoluble leach residue is separated from the pregnant leach solution (PLS) via counter-current decantation."

Jan 1, 2016

By N. Katsikaros, N. S. ‘ Yap, B. Adaszynski

"Cyanide is a well proven, effective lixiviant that has been utilised for centuries in gold extraction processes. Despite being used in close to 90% of gold processing plants, cyanide leaching is still being scrutinised due to its toxic nature. With governments tightening the regulations on cyanide management, and recently erected sites situated closer to community and environment, leach waste and tailings treatment has become increasingly important. Gekko Systems has worked with engineering companies and directly with gold producers to provide technical services and supply complete modular cyanide destruction (detox) systems for plants leaching both run-of-mine ore and high sulphide gravity and flotation concentrates. Although similar in principle, the different materials presented unique challenges in design and implementation. Similar to designing any section of a processing plant, the development of the cyanide destruction plant design began with laboratory test work to simulate the full scale operation. This paper focusses on the laboratory test work and how other critical factors such as geographical location, logistics, and local community play a role in the process design and construction. Two design and supply cases are discussed in this paper; one treating intensive cyanidation concentrate leach tails and one treating whole ore CIL tails. Although these plants both use the SO2/O2 process, each presented different challenges in laboratory testing and plant design, resulting in variations in final implementation including reagent choice, oxygen supply, and process control.INTRODUCTIONSince 1887, cyanide has played a large part in the beneficiation of gold from gold bearing ores. Cyanide is used to solubilise gold into solution, and is typically added in excess to maintain the leaching process. Some or all the excess cyanide can often be recovered and reused in the process however chemical destruction of cyanide is often necessary to manage cyanide levels in the tailings storage facility (TSF)."

Jan 1, 2016

"Geoscan is used for multi-elemental analysis of conveyed bulk materials in the minerals industry with proven performance and demonstrated paybacks of weeks or months in iron ore, manganese, copper, zinc-lead and phosphate industries. Geoscan-M measures continuously through the full bed depth and is unaffected by belt speed, particle size, layering, mineralogy and dust levels. Increments of typically two minutes are accurately measured and provide the plant operators with tonnage weighted results of contained elements. Measurement of the composition in real time enables prompt feedback to the mining operators and also feed forward to the process operators. Crushed ore increments can be diverted based on composition, such as diverting waste for disposal or marginal material to a stockpile for separate processing. Bulk sorting allows material to be placed into relevant stockpiles for subsequent blending to achieve consistency for process feed. Parameters used for decisions may be primary metal content, deleterious component content, other process parameter, or a combination of these. Process parameter may be the elemental ratio between critical components, e.g. Cu:S ratio, basicity, or the content of an “indicator” element (such as Si indicating material hardness). Benefits will be discussed based on case studies in copper and iron ore.IntroductionAs operators of process plants strive to remain competitive as capital and operating costs increase and commodity prices fluctuate, more focus has been directed at incremental performance improvements at incremental cost rather than major expansions to increase output. The philosophy of working smarter allows plants to adopt technologies proven in other industry sectors to minimise risk. This paper discusses one such technology that the minerals sector is adopting and has found to be safe, reliable and accurate with paybacks of weeks in most applications. New applications continue to be found and major benefits realised at various stages in the processing and handling of ores and products."

Jan 1, 2016

By Luis Valentim, John E. Wiegand

Highwall or face profiling has long been used to facilitate the design and placement of front row blastholes to ensure optimum burdens. Traditionally, a large number of laser measurement points obtained from the rock face or highwall, were input in profiling software packages. This method can be time consuming and requires access to the rock face with a complete view of the highwall, to be successful. Stereo photography has also been used to generate the rock face surface, but this method also requires access to the highwall (and pit floor in some instances) for measurement of reference targets or points.

Jan 1, 2016