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By Jean-Marc Simard, Richard Genest

"La mine Agnico-Eagle, localisée près de Joutel, a été découverte en 1962 par le forage d'anomalies électromagnétiques. Exploitée à partir de 1974, elle a déjà produit près de 30 tonnes d’or à partir de 2 puits, le puits Eagle et le puits Telbel, distants de 1,3 km.Le gisement est situé entre le sommet du complexe volcanique de Joutel, à dominante felsique, et la base de l'ensemble sédimentaire de la rivière Harricana. Ces deux unités ont une extension régionale; elles sont orientées NW-SE avec une polarité NE et des pendages subverticaux. Une faille majeure, la faille Harricana, passe de façon subconcordante au contact de ces deux ensembles.La minéralisation aurifère, de 2 à 5 m d’épaisseur moyenne, est liée a une zone carbonatée, comprise entre des tufs felsiques, argilites et sédiments chimiques (éponte inferieure) et des argilites carbonatées (éponte supérieure). Le minerai est constitué habituellement de 20% de fine pyrite disséminée. L’or est en fines particules associées directement à ces grains de pyrite de texture cataclastique.Deux modelés ont été for mules jusqu' a présent pour expliquer la genèse du gisement: une thèse syngenetique (Barnett et a/.1982) et une thèse épigénétique (Wyman et al. 1986). Cette dernière apparalt comme la plus probable du fait de la présence de la minéralisation dans les zones cisaillées a carbonates secondaires et pyrite cataclastique."

Jan 1, 1990

By K. Lillkung, J. Kourunen, M. Latva-Kokko

"Carbon-in-leach (CIL) and carbon-in-pulp (CIP) processes utilize activated carbon to adsorb solubilized gold for recovery. Due to carbon attrition and non-ideal carbon management, however, some of the gold is lost in carbon fines and to the solution. The carbon attrition mechanism inside CIL/CIP reactors is mainly abrasion-related. This is critical to gold loss since gold loading takes place predominantly in the outer shell of the carbon particles. Thus fine carbon dust has a relatively high gold content and such a small particle size that it cannot be captured with safety screens. The attrition rate depends on ore and carbon characteristics, but it is always proportional to the mixing power intensity. This rate can be minimized by continuous suspension level measurement and control of agitation speed. In addition, a novel tank bottom structure can significantly reduce the required mixing power input compared to a flat bottom tank. A major challenge in carbon management is infrequent and inaccurate measurement of carbon concentration in the reactors. In order to reduce soluble gold losses by means of improved carbon management, Outotec has been developing a continuous in-situ measurement for carbon concentration that is tolerant to changes in slurry density.INTRODUCTION Cyanide leaching has been utilized since the late 19th century as a standard technology for hydrometallurgical gold production. Since then, gold and silver recovery rates have increased due to technological development, but very similar recovery methods are still being used. The original recovery method was to use zinc precipitation – similar to the Merrill-Crowe process, which is still common for feed materials with low throughput and high silver content. However, in most cases, activated carbon recovery is preferred due to its improved efficiency. The carbon-in-pulp process (CIP) and its modification, carbon-in-leach (CIL), have a lower residual soluble gold level and are not similarly affected by soluble base metals. The main alternative for the use of carbon is ion exchange resins. The principle of resin processes is similar to the CIL/CIP processes, with a different type of adsorbent material. Carbon processes are usually preferred over resin processes due to the significantly higher cost of resin material and the possibility to use simpler, well-established technology with carbon processes."

Jan 1, 2017

By Gurupraveen Ramanathan

Slot raises are relief holes within a stope in longhole stoping methods, designed to provide a free face that facilitates the expansion of the blasted rock during blasting, ultimately achieving the desired fragmentation. Various methods are employed to produce these slot raises, like conventional drop raise drilling, raisebore & V30 drilling. However, slot drilling is generally characterized by high costs and limitations in precision, resulting in unplanned ore losses and dilution. This paper introduces a novel alternative to slot drilling referred to as the "paste slot", designed specifically for paste backfill operations in underground mining. This new method emphasizes considerations in cured paste strength, paste wall removal, and stope dimensions and employs modified drop raises or dumped rings to optimize blast gas effectiveness and material flow. The paste slot method eliminates the need for reamers and reduces the total slot drill meters an average from 650m to only 300m for narrow stopes (3-4m wide). This significantly reduces the stope cycle time, leading to substantial cost savings and increased productivity. This new method was successfully implemented at the underground mines in Canada and Australia, resulting in a 20% reduction in stope cycle time and cost savings of 53,000 USD per slot compared to the conventional slot. This paper discusses the design and execution strategy of the paste slot method in underground paste backfill operations. It highlights the advantages of the method, shares operational insights gained during implementation, and showcases its potential applicability to other mines across Canada and globally.

Oct 1, 2024

By S P. Giambra

The 50,000-ton-per-day Concentrator and Crushing Plant, complete with its related water supply, tailings disposal and concentrate handling systems, was started up in a five-month period, with the entire plant obtaining its design capacity six months after the first mill became operational. Individual mill lines, with their spiral circuits, achieved design capacities within a week after the first treatment of ore through each mill. Construction and start-up proceeded together in many areas of the plant, and considerable organization and cooperation between the Owner, the Engineer and the Contractors permitted a smooth transition from construction to operation. PLANT DESCRIPTION THE Carol Lake Plant of the Iron Ore Company of Canada l1as been well described in various technical magazines. The purpose of this paper is to present a brief outline of the start-up of the con-centration complex. This start-up was accomplished in a period of five months, with the plant producing one million tons of concentrate and achieving its design-rated tonnage less than six months after the first ore was treated.

Jan 1, 1963

By Adrian Dance

Newmont Mining Corporation?s Carlin (?Carlin?) operation processes roaster feed through a double rotator, dry grinding mill following secondary crushing. Metso Process Technology & Innovation (?PTI?) was involved in a review of crushing and dry grinding circuit operations in August 2009. A number of opportunities for increased throughput were identified in the PTI study. Extended plant trials were conducted in July 2010 to provide justification for possible circuit modifications and if needed, additional equipment. The trials confirmed that a finer crusher product would reduce the build-up of material ahead of the coarse grinding chamber in the double-rotator. Also revealed were material transport and airflow restrictions in the dry grinding circuit that resulted in a high circulating load. The secondary crushing plant demonstrated it was capable of reducing the amount of +¾? material in the mill feed thus increasing dry grinding throughput. However, wet and sticky feed affected screening efficiency resulting in low utilisation of the existing crusher capacity. The open circuit configuration also made it difficult to control crushing circuit product size. For the dry grinding circuit, changes in grinding media size, transfer grate design and increased airflow were recommended to reduce circulating load issues and increase circuit capacity. This paper summarises the crushing and grinding circuit review, the extended site trials performed by PTI and the improvements in dry grinding operation that resulted from this study.

Jan 1, 2012

By Luke Meers

Roadway development rates in Australian underground coal mines are failing to keep pace with modern longwall systems and are unlikely to sustain further improvements in longwall productivity into the future unless step change improvements to roadway development equipment and practices are made. Bottlenecks which limit and constrain improved production and impact the safety of operators have been identified through a series of industry surveys, with the manual installation of strata support materials, consumables delivery, coal haulage and monorail installation being highlighted as major areas to improve development performance. This paper looks at research being carried out at the University of Wollongong in designing an integrated system approach for the fully automated handling and installing of development consumables, and the systems required to support these activities. A series of hard automation manipulation devices have been demonstrated in surface trials and the results indicate that rapid roadway development can be achieved.

Aug 1, 2013

By S. Hill

For a mining operation, the determination of the best place to build haul roads is typically done by hand, or with the assistance of rudimentary shortest path optimisation algorithms. Straight line, point to point, modelling of costs is often used with distances multiplied by constants that are based on rise of the road between the points. Failings of this approach are that straight line approximations are notoriously poor as they do not take into account areas where a truck cannot travel. In addition, the rise and fall of the road may vary considerably over the truck journey meaning acceleration/deceleration and varying truck speeds are not taken into account. Lastly, the use of rudimentary optimisation algorithms means properties a truck must obey such as minimum turning circles, line of sight restrictions or even that the truck must travel forward at all times are not taken into account. Thus solutions generated may not be feasible, let alone optimal. In this paper we discuss a state of the art parallel Artificial Intelligence tree search technique for solving haul road location problems. As well as the above properties, factors such as road utilisation, cut and fill, and construction costs are taken into account. The combination of advanced modelling and fast computing and optimisation techniques produces significant benefits both in terms of time to generate roads and cost savings. Preliminary results where this method has been used are discussed.

Aug 1, 2013

By P. A. Peach, W. H. Gross

The modern economic geologist in Canada is well equipped to apply geological, geochemical or geophysical techniques in the exploration for ore. Recently, great advances have been made in geophysics and geochemistry, and a large number of new orebodies have been discovered by these methods. An attempt is made in this paper to show that there has also been a considerable advancement in geological knowledge and that the most effective application of geophysics and geochemistry often occurs in areas already considered geologically favourable for the occurrence of ore. Ali exploration methods sooner or later suffer from diminishing returns. Therefore, as time goes on, one can expect to see the application of some of the more subtle or refined geological techniques that are presently being developed.

Jan 1, 1967

By A. Manouchehrian, M. Cai

"Rockburst, which often occurs around underground openings in highly stressed hard rocks, is a sudden and violent unstable rock failure and is associated with energy release. Rockburst is very dangerous to workers and mining equipment, and it has been a major concern for deep underground construction and mining. Before excavation, rocks are loaded under a true-triaxial condition. Upon excavation, the rocks at the excavation boundaries are loaded in the maximum principal stress direction and unloaded in the minimum principal stress direction and this provides a necessary condition for unstable rock failure to occur. Understanding rock behavior under true-triaxial unloading condition is critical for developing measures to control unstable rock failure in underground construction.In this article, an explicit FEM tool is used to simulate rock behavior under true-triaxial unloading condition, with a focus on analyzing stable and unstable failure and the released energy during failure. Firstly, a uniaxial compression test was simulated. The results indicated that the adopted numerical tool was able to simulate stable and unstable failure by varying the Loading System Stiffness (LSS). In this research, Loading System Reaction Intensity (LSRI) was proposed as an indicator to identify stable and unstable failure. Secondly, unstable rock failure under true-triaxial unloading condition was simulated. A rock specimen was loaded in three directions; the lateral pressures (s3 and s2) were kept constant and the vertical stress (s1) was increased to a pre-defined stress. The specimen was suddenly unloaded in the minimum principal stress direction (s3) and loading in the s1 direction was continued until failure occurred. Different LSS values were considered and the results showed that the LSS influenced the failure mode; a soft loading system resulted in more violent failure and released more energy than that in a stiff loading system. The influence of specimen height to width ratio on rock failure was also investigated. It was found that failure in taller specimens was more violent than that in shorter specimens. Insights gained from the simulation are useful for better understanding of the influencing factors on the released kinetic energy during unstable rock failure and to find means to control rockburst damage in engineering practice."

Jan 1, 2015

By M. Santaluce

"The revamp of critical process assets that require a significant plant outage (shutdown) presents a unique and demanding set of challenges for plant operators. They are executed in a more complex Brownfield environment, typically with limited working space and often involve unknown conditions or scope. For plant operators, such a project is often a high cost event both in terms of opportunity cost of lost production and the resource cost of labor and materials. It can also be a high risk event in terms safety, environment, and future plant reliability/availability. This impacts current and future performance or Overall Equipment Effectiveness (OEE). In our experience, the sequential nature of the EPCM approach does not provide the proper framework to facilitate the level of coordination, stakeholder cooperation and detailed planning required to adequately address the construction and shutdown complexity of a critical asset revamp projects. This paper proposes a more integrated approach to handling shutdown revamps of critical assets. Its main thesis is to involve the key performing stakeholder groups early in the project lifecycle (engineering team, procurement team, construction team and plant operations) to form an integrated shutdown management team that is focused on ensuring delivered results are aligned with project objectives. In this model, the construction team executing the shutdown/construction is preparing the detailed shutdown/construction planning concurrently with detailed engineering and procurement planning. This allows construction/shutdown requirements to influence engineering and procurement, with the desire to optimize safety, speed, quality and cost. The paper also discusses how to overcome the procurement hurdle in applying such an approach. The outcome of this integrated approach is better planning, coordination, communication and alignment between the project stakeholders, a shutdown/construction driven planning approach that more fully addresses the challenges of these projects and delivered results that are aligned with project objectives."

Jan 1, 2015

By H. Lazreg

This paper presents an evaluation of surface resistivity techniques as a tool for delineating salt-water intrusion in Shippegan, N.B. The study consisted of resistivity profiling, resistivity soundings and a limited number of induced polarization soundings in selected areas in the Province of New Brunwick. The results from resistivity profiling indicate that when seawater intrusion occurs in a sandstone formation the resistivity contrast is sufficiently large to allow a precise delineation of the intrusion. A formula is then derived to convert resistivity values to chloride concentration in the "cone of intrusion". The results from resistivity soundings showed that shaly formations may have resistivities as low as seawater-contaminated sandstone. An indeterminacy has resulted from this resistivity overlap. A limited number of IP soundings were performed in an effort to resolve it. The results showed that IP can be of appreciable help in resistivity interpretation.

Jan 1, 1972

By O. Babak, J. G. Manchuk

ABSTRACT A significant factor in evaluating bitumen recovery from an oil sands mine is the particle size distribution (PSD). Increased understanding of mined ore quality and improvement in predictions of recovery can be achieved through PSD modeling. This paper addresses PSD modeling using geostatistics. PSDs may be described using many discrete particle sizes, making this a challenge. The approach parameterizes PSDs with a few statistics. A lookup table is used to reconstruct the PSDs based on models of the statistics. The workflow is applied to Total E&P Canada’s Joslyn Lease and yields good results that reproduce input statistics without introducing artifacts.

Jan 1, 2013

By D. Purdie

"This paper aims to remind researchers, designers, operators, and managers about the benefits of seeding in the design of precipitation stages in their flowsheet. Including a high density solids (HDS™) process encourages the precipitating solids to form on the surface of existing precipitated particles. This paper discusses the application of the HDS technology at Kennecott Smelter, where the authors have witnessed significant improvements in settling and filtration rates. The authors have also applied this technology at various smelter bleed treatment plants worldwide with similar improvements in precipitation and filtration rates. HDS is a registered trademark of De Nora Water Technologies. RÉSUMÉ Cet article a pour objectif de rappeler aux chercheurs, aux concepteurs, aux exploitants et aux administrateurs les avantages de l’ensemencement dans la conception des étapes de précipitation de leur schéma de traitement. L’introduction d’un procédé des boues haute densité (procédé HDS™, de l’anglais high density sludge) encourage la formation de substances solides précipitantes à la surface des particules précipitées existantes. Cet article porte sur l’application de la technologie HDS à la fonderie Kennecott, où les auteurs ont observé des améliorations importantes au niveau de la vitesse de sédimentation et de filtration. Ils ont également appliqué cette technologie à diverses usines de traitement des rejets liquides des fonderies dans le monde entier, et ont constaté des améliorations similaires en termes de vitesse de précipitation et de filtration. Le procédé HDS est une marque de commerce déposée du fabricant De Nora Water Technologies.INTRODUCTION In 1966, the lead author worked as an assistant smelting metallurgist for the Tsumeb Corporation Limited copper and lead smelter in Tsumeb, Namibia. The smelter produced copper and lead, as well as cadmium and arsenic trioxide as byproducts. The cadmium was concentrated in the lead blast furnace off gas dust, and was collected by a baghouse. The baghouse dust was leached with dilute sulfuric acid (H2SO4) in a batch process. The iron and arsenic in the solution were oxidized with potassium permanganate (KMnO4) and basic ferric arsenate (BFAS; Fe(AsO4)x(SO4)y(OH)z·wH2O) was precipitated using milk of lime. The cadmium was cemented from the purified solution using zinc dust."

Jan 1, 2018

By D. Hu, L. Matzar, J. Hampton, M. Gutierrez

Nanodarcy permeability is common in many oil- and gas-bearing formations requiring unconventional stimulation technologies, such as hydraulic fracturing (HF), which can connect the isolated hydrocarbon-rich pores with a wellbore through induced fracture networks. Even though a dense induced fracture network is capable of accessing economic amounts of hydrocarbons, much of the rock between and very close to the fracture network is still un-accessed and contains extremely low permeability. Inducing fracture networks into brittle rock can create large amounts of micro failures in surrounding regions that are not connected to the wellbore, as can be seen in Fig. 1(a) from the very wide acoustic emissions (AEs) cloud associated with a narrow fracture generation. It is possible in certain types of rock to increase the effective matrix permeability in localized regions based on the damage associated with the surrounding hydraulic fractures and subsequent high stress concentrations along localized pre-existing potential failure zones. To study this problem, laboratory HF tests were performed at true-triaxial stress state in brittle crystalline rock while monitoring AEs. The AE associated with HF was analyzed for source parameters using the moment tensor inversion method called Simplified Green’s Functions for Moment Tensor Analysis (SiGMA). Using the moment tensor for each individual AE event, the mode of failure was determined. Crack slip directions and crack face normal directions were also found, along with the relative volume of individual micro failures as well as a damage parameter. The associated source parameters were used to classify differing regions of damage in the sample induced from HF and correlate these regions of differing damage to the effective drainage region. Shown in Fig. 1(b) is a near-wellbore (NWB) region that contained three times larger average relative volumetric deformation of individual tensile AE events than the average tensile AE event volume from the entire sample. Because of the large difference in micro fracture volumetric deformation for the NWB region compared to the entire sample, predictions of HF induced damage must be included in reservoir drainage predictions.

Jan 1, 2015

By B. Daniels, A. Tieu, W. Yan, B. Ren, M. Vijay

"Plasma or thermal sprayed coatings are becoming more widely used in a wide range of industrial applications. The preference to use thermal sprayed coatings is mainly attributed to its superior wear, and corrosion resistant properties akin to hard chrome but without the harmful health implications of chrome in the coating process. Specifically, High Velocity Oxygen Fuel (HVOF) plasma sprayed Tungsten Carbide & Cobalt (WC/Co) coatings are presently being tested on aircraft landing gear. This coating can be efficiently applied and is highly resistant to corrosion and wear. However, HVOF coating's durability also makes it difficult to be stripped for inspection and overhaul. Current coating removal methods usually involve a multi-step process whereby the coating must undergo diamond wheel grinding, chemical dipping, grit blasting, ultrahigh pressure (UHP) 380 MPa (55 Kpsi) water blasting, and subsequent chemical dipping, depending on the type and thickness of the coating. As explained by Yan, et al [l]"" a unique method has been developed for removing HVOF coatings with the use of only water. The method consists of modulating a stream of water at a pressure of only 69 MPa (10 Kpsi) with ultrasonic waves to generate a forced pulsed waterjet. The resulting cyclic loading of the hard coating due to the impact of the water pulses easily causes it to flake off the substrate. This paper will briefly describe the fundamentals of the forced pulsed waterjet technique with an emphasis on insitu applications of the removal of various plasma and HVOF coatings."

Jan 1, 2006

By J A. Gilliand

Mineralogical cross sections of orebodies on the 300-,600- and 900-foot levels of the Coronation mine have been interpreted in terms of centers of mineralization. The maximum concentration of chalcopyrite occurs closest to these centers, with pyrite and pyrrhotite concentrated some distance away. The magnetite concentrations are farthest removed from the centers. A hydrous halide fluid model is established. Attempts to explain the observed mineralogy by the action of temperature gradients on the fluid model were unsuccessful. Likewise, the action of diffusion alone on the fluid model cannot explain the observed mineral distribution. The concept of attenuation is introduced-i.e., the rate of diffusion of a particle species is related to the product r2 I/ M, the attenuation coefficient, where r is the particle radius and M its molecular weight. Attenuation, acting on the fluid model alone, will not produce the observed mineral distribution, but, when considered together with the action of temperature gradients, the observed mineralogy can be well explained by the combined effects of these two processes on the assumed fluid model.

Jan 1, 1965

By A. R. Harrington

BEFORE discussing some of the technical aspects of the steam generating plants of Nova Scotia Light and Power Company, Limited, it might be of interest to go back through history and see the development of steam generation in this public utility. Back around 1902 Nova Scotia Light and Power Company, Limited, had three slide-valve engines in-stalled at its Water Street, Halifax, generating station for a total capacity of 1,800 kilowatts. The plant remained at about this size until 1910 and in 1911 a 2,000 kilowatt steam turbine was installed to raise the total capacity of the plant to 3,800 kilowatts. In 1916, a 3,000 kilowatt turbine was installed and one of the slide-valve engines was removed to make a total plant capacity of 6,200 kilowatts. The total demand in the Company's service 8rea was at that time 4,000 kilo-watts.

Jan 1, 1958

By L. Zeng, Q. Feng, Z. Qiu, L. Ou, Central South University

It is well-known that the use of nanobubbles can significantly improve the flotation efficiency of ultra-fine particles. However, this is mainly focused on coal and phosphate rock flotation. In the field of nonferrous metal processing, the related research is few. In this paper, a small laboratory mechanical cell associated with a specially-designed nanobubbles generator was used to investigate the effects of nanobubbles on enhancing ultra-fine scheelite flotation. Nanobubbles were created and based on the hydrodynamic cavitation principle through Venturi tubes. Comparative flotation tests were performed using different tubes to evaluate the nanobubbles impact on the ultra-fine scheelite particle flotation recovery. In order to better understand the nanobubbles enhanced ultra-fine scheelite flotation, nanobubbles potential and size distribution were measured. The effect of nanobubbles on the particle aggregation and scheelite particles potential were also studied through the turbidity tests, microscope tests and zeta potential measurements. According to the results, the mean size of nanobubbles was about several hundred nanometers, and the surface of nanobubbles was of highly negative charge in alkaline conditions. The flotation recovery of ultra-fine scheelite particles was increased in the presence of nanobubbles. The zeta potential measurements indicated that the repulsive forces between scheelite particles decreased when nanobubbles existed. Through the turbidity tests and microscope tests, the promotion effect of nanobubbles on particle coagulation could be verified more directly. The existence of nanobubbles in flotation system promotes the particle aggregation, thus increasing particles apparent size and particles capture by bubbles, which may be the fundamental reason why nanobubbles enhance ultra-fine scheelite flotation.

Jan 1, 2016

By H. G. Wang

The production process of a coal mine can often be interrupted by all kinds of events scheduled or unscheduled and thus often needs gas drainage for a temporary or long-term sealed area. Gas drainage has a relatively high risk, therefore attention must be paid to its design to keep the process safe. Based on the conservation laws of mass and constituents, and under the conditions of the allowable gas concentration limit in the return air route, the relationship between gas concentration and gas drainage flow rate as a function of time during the drainage process is discussed in detail to build a mathematical model of gas drainage from a sealed area. With respect to the gas drainage process, two different conditions need to be considered: one with a methane free fresh air supply, the other with a low gas concentration. This paper presents the derived mathematical models for these situations and then shows that they can be incorporated into one model with some modification. This combined model can be employed to determine the optimum gas drainage flow rate with the shortest drainage time. The application is coded using the C# programming language within the .NET framework. Finally, the application program developed by the author is used to validate the mathematical model through an example of gas drainage with varying rate.

Aug 1, 2013

By J. G. Stevens, S. W. Colley

"Selective separations of metals and ions in mineral extraction and refining are becoming more challenging as ore bodies become more complex and environmental pressures increase. The separation and containment of mercury produced in gold mining are a factor in the profitability and operability of mines. This paper will discuss the development and implementation of the Johnson Matthey HgFree selective mercury removal process. The process is designed to selectively recover co-leached mercury from either heap leach pregnant solutions at ambient temperature and low mercury concentrations, or electrowinning pregnant solutions at elevated temperature and high mercury concentration, without affecting gold or silver recovery. The process utilizes a highly selective adsorption-desorption step in which mercury is removed quantitatively by the HgFree adsorbent without adsorption of gold, silver or other metals present. Development of the original HgFree adsorbent has resulted in a process whereby mercury can be recovered as an inert salt and is never present as the free metal. The HgFree adsorbent can be regenerated and recycled in situ, and is capable of being reused multiple times. The overall process is compatible with existing gold mining and recovery practices and offers significant environmental and sustainability benefits, including reduction or elimination of the need to retort mercury with a subsequent reduction in potential mercury air emissions. Development of the HgFree adsorbent and process will be discussed along with a pilot operation at two operating mines.INTRODUCTIONMany gold ore bodies contain high concentrations of mercury which when extracted with cyanide, co-extract with the gold and other metals. This mercury is carried through the process with the gold, posing environmental and technical issues when it is separated from the doré. This paper describes a method to selectively adsorb mercury from the gold recovery circuit while it is in a soluble form, leaving gold to be processed as normal. The removal of mercury from the circuit eliminates the need for mercury retorting of doré and so reduces the potential environmental impact of fugitive emissions of elemental mercury."

Jan 1, 2016