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By Jean Robitaille

La découverte du gisement du puits Penna a nécessité une révision complète de tous les circuits du concentrateur Laronde pour permettre, premièrement, l?adaptation du procédé à la nouvelle minéralogie et deuxièmement, l'accroissement du tonnage de 1800* à 4500 t/j. Aux circuits existants de broyage, de flottation du cuivre, de cyanuration et du charbon en pulpe, les circuits suivants furent greffés : broyage semi-autogène, flottation du zinc, manutention des concentrés (épaississage, filtration, entreposage et chargement automatisé), décantation à contrecourant et précipitation au zinc, destruction des cyanures et remblai en pâte. Cet article se veut une revue des différentes étapes du projet d'agrandissement du concentrateur qui se sont effectuées par phases progressives de 1997 à 2000. De plus, une description des nouvelles technologies sélectionnées et implantées est présentée.

May 1, 2001

By P. Plante

Contaminated neutral drainage (CND) is characterized by the presence of metal concentrations above regulatory requirements at circumneutral pH in mine drainage. The generation of CND by tailings and waste rocks is a growing concern for the mining industry due to increasingly restrictive regulatory requirements. Difficulties in CND prediction arise from the low oxidation rates of sulfide minerals and from the metal retention potential within the wastes. In fact, sorption phenomena may induce an important delay in the development of CND. For now, it is not possible to adequately consider this delay using the prediction tools developed for acid-mine drainage, such as humidity cells, columns and lysimeters. This work aims to present the new approaches currently under study for CND prediction, particularly the use of a chelating agent in kinetic tests. The main challenge of CND prediction is to quantify the metal retention potential of mine wastes, especially when sorption phenomena are involved in metal retention. Three approaches are currently used to overcome this difficulty. Firstly, the sorption potential is estimated using batch sorption studies. The second approach consists of artificially saturating the sorption potential of the mine waste by contact with a contaminated leachate in sorption-enabling conditions until saturation of the retention potential. These approaches both require that the possible metals involved in CND are known (as well as their chemical speciation) prior to the tests, which require an exhaustive material characterization. Although the two methods enable a qualitative estimation of the retention potential of mine wastes, their results are difficult to scale up from the laboratory to the field since some important parameters are not taken into account. A third proposed approach consists of inhibiting metal sorption at the source using chelating agents. The hypothesis is that chelating the metals immediately upon their release from the oxidation of sulfide minerals will inhibit all geochemical interactions (sorption, complexation, secondary mineral precipitation, ion exchange, etc.) between the metal and its environment. The ideal chelating agent will inhibit geochemical interactions after metal release in the drainage waters without having any impact on the sulfide oxidation and acid neutralisation rates. These approaches were tested over a waste rock sample that is known to naturally generate CND after a few decades of weathering. Results show that kinetic testing (weathering cell, ± 70 g samples) using a chelating agent (EDTA) in the leaching water renders higher metal concentrations in the leachates than a control sample without EDTA, suggesting that sorption (and possibly other geochemical interactions) is inhibited. These results suggest that the combination of these approaches can be efficiently used for more precise CND prediction from mine wastes. Future work will be done using the chelating agent approach over larger scale tests such as columns (± 80 kg samples) and field cells (± 100 tons) in order to propose an integrated approach for CND prediction.

Aug 1, 2013

By A. M. Simons

Cyanide destruction by Caro’s acid is one process commonly employed by gold operations to meet regulatory requirements and/or the International Cyanide Management Code compliance for weak acid dissociable (WAD) cyanide in cyanidation tails or waste water from such operations. Typically smallscale bench tests to evaluate and assess the suitability of the Caro’s acid destruction process are conducted. Additionally, the experimental procedure used during these preliminary investigations may also differ from that implemented at the full-scale. This paper presents the results from a fundamental investigation of the Caro’s acid process to establish a more detailed understanding of the impact that the experimental procedure has on the destruction of cyanide. In particular, it was found that the control of pH was important to avoid copper(I) cyanide precipitation at low pH and maximise WAD cyanide destruction. Residual peroxide in the preparation of Caro’s acid has the potential for subsequent cyanide destruction and could be exploited.

Jan 1, 2014

By I. Thobadi, C. Pawlik, K. Bisaka, S. Mokoena, M. Erwee

The PyEarth™ process developed at Mintek has been demonstrated successfully at pilot scale. Nine tons of ore containing 2.3 mass % of total rare earth oxides (TREO) from a dormant mineralogically complex iron-rich ore deposit, was subjected to a concentrating smelting step in a 200 kW DC open-arc pilot furnace and the rare earths from the resulting slag were extracted via a hydrometallurgical route. This ore deposit is practically not amenable to extraction by conventional methods. The testwork results proved that the PyEarth™ process was able to optimize the extraction of rare earths while minimizing waste through the removal of iron as a saleable iron alloy. Reduction of iron to the alloy in the smelting step was found flexible, efficient, and controllable, while rare earths were left virtually unreduced in the slag phase. The slag chemistry is selected to optimize both the smelting and leaching performances as well as the alloy composition. Leaching of the resulting slag was found possible and most efficient in hydrochloric acid amongst other lixiviants tested.

Jan 1, 2017

By C. V. Corless

1. Introductory Some members may recall that at the Annual Meeting two years ago I read a paper, 'The Future of the Mining Industry in Canada." Discussing this large subject it was possible only to outline the facts and inferences leading to ?the conclusion that Canada is a country endowed with enormous mineral wealth, of which the fringes are yet scarcely touched. In the present paper, I wish to examine in somewhat fuller detail the evidence, both direct and inferential, concerning the mineral wealth of the greatest physical and geological feature of Canada-the Precambrian Shield. Many, if not most, of these facts are already familiar to you. But, since they will form the basis of the reasoning employed, they will be recalled for explicit reference. First, let us review very briefly the position and extent of the Shield. The area of the entire Shield is given in textbooks as 2,000,000 square miles, of which perhaps 10 or 12 per cent. is exposed in the south-easterly part of Canada's Arctic islands. The remainder occupies roughly two-thirds of the North-west Territory; the north-east corner of Alberta; one-third of Saskatchewan ;two-thirds of Manitoba; three-fourths of Ontario; and nearly ninety-five per cent. of Quebec.

Jan 1, 1924

By George Rice

Foreword Following the explosion in the Hillcrest mine, which occurred in the evening of Sunday, September 19th, 1926, and in which two men lost their lives, the writer was invited by the Hon. J.E. Brownlee, Premier of Alberta, to conduct an investigation into the causes of the disaster, and to make such recommendations as seemed advisable with a view to minimizing as far as possible the chance of future explosions in this and similar Alberta coal mines. Accordingly, the mine was visited, and extensive investigations were made underground on October 21st, 2.2.nd, and 25th, in company with Mr. John T. Stirling, Chief Inspector of Mines for Alberta, Mr. Moses Johnson, District Inspector for the Crowsnest Pass District, Mr. J as. A. Richards, Inspector of Mines, Edmonton, and also Mr. Thomas Davies, manager, and other officials of the Hillcrest mine. Hearings of the coroner's inquest were also attended on October 20th and 23rd, when testimony regarding the explosion was given by various witnesses. The following paper summarizes my general observations in tracing the place of origin of the explosion, and my efforts to determine the cause of ignition. Certain recommendations arc also made, and the writer invites discussion on these and the other matters dealt with in the paper.

Jan 1, 1928

By Wallace R. Horn

"MR. CHAIRMAN AND GENTLEMEN :I begin this talk by making a couple of comments which are of the nature of disclaimers.Firstly, and as the Chairman has otherwise indicated, I was neither ""born into"" nor have I spent more than a few years of my professional life in the mining industry. I mention this because many might, and perhaps rightly, consider that an added qualification in presenting a report of what the industry has accomplished. Indeed, I am not here to blindly defend all of its actions and inactions in respect to environmental control over the years. Nor am I here to seek absolution of the industry's past transgressions - if indeed that is the word. Mistakes might be a better one. I concluded some time ago that the effects of those mistakes are too difficult to assess against the sea of errors of our total society. I should mention too that I am not an environmental engineer or specialist - only a portion of my interest is involved with this field. Perhaps this permits a perspective which allows a more accurate and objective view.One further comment here. My job today, as I understand it, is to generally report upon the nature and extent of the response of the metals mining industry to control of the environment. In the case of an industry operating at more than a hundred locations and for various reasons at various stages of progress, it is not an easy job. On the other hand, I wanted to avoid the use of generalities because, especially within the context of environmental or ecological opinion and of the practice of condemnation of industrial segments, I think we've had about enough of generalities until we know far more than we do.Finally, I am quite aware that a statement of future plans to achieve environmental control does not impress or satisfy as many people as it may have done some years ago. Public opinion demands to know what is currently underway, today."

Jan 1, 1972

By F. H. Samuel, H. Tahiri, S. Valtierra, H. W. Doty, A. M. Samuel

L'affinage des grains dans les alliages d'aluminium consiste à augmenter le nombre de sites de cristallisation de la phase a-Al afin d'obtenir une structure fine. Les alliages mères de type Al-Ti-B sont largement utilisés comme raffineurs des grains. Cette étude a pour but d'établir des mécanismes convenables d'affinage des grains dans l'alliage A356 en utilisant cinq alliages mères et deux températures de coulée (750°C et 950°C). Les résultats montrent que la phase a-Al prend une forme selon l'alliage mère ajoute; les échantillons coules a haute température montrent une taille de grain plus grosse; les températures de germination et de croissance augmentent avec I' augmentation du Ti ou du B et la taille des grains diminue. L'alliage mère Al-4%B montre une puissance remarquable en comparaison d'autres alliages mères. Pour cet alliage mère, le titane résiduel dans l'alliage A356 réagit avec le bore pour former TiB2 qui, par la suite, agit comme un germe actif pour la phase a-Al.

Jan 1, 2006

By H. A. Oaks

FROM 1921 to 1939, the aeroplane played an increasingly important role in Canadian prospecting and mine development. This service has been interrupted by the war, but undoubtedly it will be accelerated in the postwar years, if suitable aircraft are available. The purpose of this paper will be to review the uses to which the aeroplane has been put in prospecting and development in the past, and its future possibilities as an aid in prospecting. If by review, and deduction, we get a clear picture of what we expect the prospecting plane to do, we may be able to arrive at a very close approximation of its required characteristics and, from this, an idea of costs. 'Function' is defined as the mode of action by which it (the aeroplane) fulfills its purpose. We will endeavour, therefore, first to find what this purpose is, or should be, so that our expectations will not be too limited nor too great-and then find, by analysis, what performance we require in an aeroplane to meet our reasonable expectations at an economic price.

Jan 1, 1945

By E. Sharifi, B. Komishke, R. Heffel, D. Schwartz

"The oil sands resources in Canada are one of the world’s largest hydrocarbon deposits. Processing of oil sands uses hot water to extract bitumen. The process generates tailings slurry that must be settled for final deposition. The tailings contain fine material, with poor water release characteristics which makes water recovery challenging. Polymer flocculants are added to assist in settling and dewatering the fine tailings. The amount of polymer addition is dependent on tailings characteristics, including the particle size distribution (PSD). If the PSD of the tailings is unknown, an excess amount of polymer needs to be added in the dewatering stage to flocculate the particles. Over flocculation also has a detrimental effect on the water release characteristics. Measuring the particle size distribution using an on-line analyzer could have major benefits over common laboratory methods as it provides online and fast insight into the process enabling the operators to implement required changes to minimize the reagent consumption, while achieving optimal flocculation. Online measurement of PSD using laser diffraction has long been used in base metals beneficiation processes. A series of test work using Outotec PSI500® particle size analyzer on oil sands samples from different operations have been conducted. Tests were performed by recirculating the slurry in closed circuit to simulate real plant conditions. This paper presents a summary of the results.INTRODUCTION Canada’s oil sands are the third largest reserves of crude oil in the world, with an estimated 165.4 billion barrels of recoverable oil (Government of Alberta 2016). Oil sands are a mixture of sand, water, clay and bitumen. Bitumen is a form of oil that is too heavy or thick to flow or be pumped without being diluted or heated. About 20% of bitumen reserves are close enough to surface to be mined. In mining methods, oil sand is transported from an open pit mine to the processing plant and bitumen is separated from solids and water. The separation process involves ore preparation, such as addition of hot water, steam and caustic (NaOH), followed by gravity separation and froth treatment (Masliyah et al. 2004). A general scheme of the extraction process is presented in Figure 1."

Jan 1, 2018

By J. E. Amadi-Echendu, F. Stober, J. Ndlovu, L. R. Nelson

The Polokwane Smelter Complex (PSC) relies on a single 68MW high-intensity six-in-line furnace to smelt a planned 650 000 t/a dry concentrate to produce a platinum group metals (PGM)-bearing matte. As typical of a greenfields venture, considerable attention was paid to the project development and implementation stages of design, engineering, construction and commissioning. Somewhat unusual though, was the role of a dedicated multi-disciplinary "Operational Readiness" and support team, comprising the owners team and specialists from the furnace designer, HATCH, to effect a safe and rapid ramp-up to the design smelter capacity of 68MW. The challenges encountered in developing an effective partnership will be discussed. The modus operandi and roles of the "Operational Readiness" team during the design, procurement, construction and commissioning stages as well as that of the operational support team within the overall ramp-up objective will be presented. The "Operational Readiness" team was responsible for:

Jan 1, 2005

By R. W. Lawrence

"The management of acid rock drainage( ARD) to prevent impact when tailings are disposed of in the environment requires understanding of the phenomena giving rise to acidic drainage, a rigorous evaluation of the weathering characteristics of the tailings, and the successful implementation of control measures that will be effective in the long term. This paper provides a brief theoretical background to the complex reactions taking place in mill tailings containing residual sulfide minerals which must be appreciated to enable waste characterization program to be effective in predicting the future behavior of the tailings and in designing control methods which will work. The principals and practice of prediction and control as part of an ARD management strategy will then be discussed.Paper Not Available at Time of Publication"

Jan 1, 1997

By Karl J. C. Harries

"8.1. INTRODUCTIONThe purpose of this chapter is not to provide precedents or examples of provisions, but rather to offer some comments that may be worth considering in the negotiation or review of an agreement. These comments are not intended to be exhaustive. It must also be noted that, although the chapter is written in the context of a common law joint venture, the concepts and concerns for the most part apply equally to a corporation that is owned by only a few shareholders for the purpose of participating in the project held by the corporation.The corporation has the advantage of having much of its organization established by local corporate law, but the particular wishes of the shareholders will appear in a shareholders’ agreement. The principal differences will be surprisingly small, save for the acquisition provisions that appear in a farm-in agreement1 and the substantial portion of the joint venture agreement devoted to creating and organizing the joint venture entity. Where the joint venture agreement refers to venturers and committees, the shareholders’ agreement will refer to shareholders and the board of directors, but both will have to deal with such basic matters as decision-making, default, dispute resolution, first refusals, funding, and carrying out work on the project. For convenience, this chapter usually refers to “venturers”, which may be taken to include shareholders.Negotiations give rise to many varying circumstances and concerns, and the main asset of the negotiator is an open and flexible mind. A desired result can often be accomplished indirectly in circumstances where the other side has adopted an inflexible position on a suggested approach. As precedents and standard forms tend to focus a negotiator’s thinking, they can be counterproductive. It is after the deal has been agreed to that a precedent can be of great assistance to the draftsman.The concepts are arranged in alphabetical order for convenience, not to suggest their sequence or position in an agreement or their relative importance. An agreement should adopt a progression of subjects in what the parties consider a logical sequence to read and work with. However, experience has indicated that it is best to set out in a single article the substance of the deal (i.e. the terms relating to the farm-in and what the acquiring party has to do to acquire his interest), preferably near the beginning of an agreement. The acquisition of the interest is, after all, the first order of business. The joint venture provisions will then follow in a reasonable sequence. It is also worthwhile to devote a single article to any special provisions that may apply during the earn-in period. For example, it may be provided that, although all work is to be done by the acquiring party as operator (with the duty of care, liability, and reporting requirements as set out in the joint venture sections of the agreement), but during the acquisition period, the acquiring party, acting as operator, may be at liberty to do such work as he wishes, without the need for any committee or other approvals, and committee meetings may be suspended.2An agreement is divided into paragraphs and articles to make it easier for the parties to read and understand, and to assist a party in finding “that provision” when the need arises. A comprehensive table of contents will also assist the parties who must work under an agreement. An added benefit of a table of contents is that in preparing it, the draftsman sees the overall structure of the agreement and will often catch and correct flaws."

Jan 1, 2003

By Fred C. Delabbio

The successful implementation of a new technology in an underground production mine requires many challenges to be overcome. These challenges include mine hardening of new technology, mitigation of safety risks and hazards, mine operation support, and technology transfer to mine staff. In the end, the majority of these challenges relate to the human aspects of implementation. The approach selected to overcome these challenges must be customized and appropriate for each unique situation. This paper outlines the approach used to address these challenges as part of successful implementation and resulting demonstration of the hydrogen fuel cell locomotive at the Placer Dome (CLA) Limited, Campbell Mine. This technology demonstration at Campbell Mine is critical for determining technical, regulatory and implementation aspects to be incorporated into future fuel cell prototypes such as the LHD project.

May 1, 2003

By Magnus Evertsson, Johannes Quist

HPGRs have since introduced in the 1980s (Kellerwessel, 1993; Schönert, 1988), now become integral comminution units at several minerals processing plants around the world. Even though a lot of the initial issues concerning performance, availability and wear have been addressed and solved there are still phenomena and aspects which can be improved and understood further. Schönert and Sander (2002) presented experimental results and a mechanistic model including the internal force dynamics between the rollers and the compacted bed. They derived expressions for the pressure distribution involving most of the influencing terms and effects. However, in order to solve the differential equations several of the terms vanish by assumptions. The Schönert and Sander model reflects the experimental data in many aspects but the predicted shear force distinctly deviates from the experimental results at the angular position of the peak pressure level. This finding suggests that the particle to particle interaction and breakage process in the different zones seen in Figure 1 are complex and difficult to model using analytical models. A numerical modelling approach using DEM does not require the same amount of assumptions and simplifications of boundary conditions. Hence such modelling may provide further knowledge and vital understanding. In this paper the breakage process is simulated in order to investigate the shear slip behaviour and how it relates to different operating variables. A laboratory scale HPGR corresponding to the experimental setup used by Schönert (2002) have been modelled in EDEM (DEM-Solutions). The bonded particle model (BPM) is used for modelling quartz particles (Potyondy, 2004). The breakage model strength parameters are calibrated against interparticle breakage experiments in an Instron 400RD compression device. The contact model parameters are calibrated using calibration methods developed by Quist (2015). The floating roller dynamics are modelled using a spring-damper system. Results present insights regarding the interparticle slip behaviour as well as the frictional tangential force distribution on the rollers. The simulated roller pressure distribution shows good correspondence with previously reported findings in the literature.

Jan 1, 2016

By Robert B. Parsons

"1984 was an eventful year in the courthouse f or observers 0/ the mining tax scene in Canada. For the first time in a number of years, the Federal Court heard several important tax cases which pertain directly to the resource industries. Tax Notes discusses/our cases that could affect the taxation 0/ operations and investment in the mining sector.Capital Gain or Income?Ever since tax reform, risk-takers in the exploration business have maintained that the taxation of capital gain s is a significant impediment to raising risk capital. It must be akin to rubbing salt in the wound, then, when an entrepreneur sells shares and the Court upholds Revenue Ca nada taxing the gain as ordinary income instead of capital gain. But, this is precisely what happened in the case of The Estate of Murray Watts, et al. v. The Queen.The issue that had to be decided by the Federal Court, Tri al Division, in this case was whether or not the profit from the sale of shares in Hearne Coppermine Exploration s Limited in 1968 was a capital gain, or income subject to tax.Hearne was incorporated in July, 1967. At that time, the three plaintiff s, together with seven other individuals, subscribed for 400,000 shares at 10 a share. The plaintiff subsequently subscribed for an additional 500,000 shares at $1.A pooling agreement was entered into by all ten shareholders regulating the disposition of any o f their shares; any sale required approval of seven of the ten initial sub scribers. It also provided for the sale of their shares 30 days after any public offering."

Jan 1, 1985

By Robert B. Parsons

"Originally intended to be implemented in 1977, but actually introduced effective May 6, 1974, the earned depletion regulations have been substantially refined and modified since their appearance on the Canadian tax scene, so that this important legislation now consists of a highly complicated set of rules which even the most astute follower of tax law has considerable difficulty sorting out!This month, Tax Notes attempts to cut through this bewildering array oj regulations, in reviewing the main features of the earned depletion allowance applicable to mining operations. Despite the phase-out of earned depletion allowances for most oil and gas operations as part of the federal government's new National Energy Program, earned depletion provisions are still alive and well for the mining sector, although they might well be slowly strangling to death in their own entanglement of complexity!"

Jan 1, 1981

By Roger Lacroix

L?arrivée de nouvelles technologies sur le marché des foreuses portables combinée au besoin des mines à mieux consommer l?énergie électrique ont permis d?identifier le potentiel de deux nouveaux type de foreuses présentement utilisées en Afrique du Sud, à savoir les foreuses électriques et les foreuses hydrauliques actionnées à l?eau. Grâce à la collaboration de mines Niobec et Géant Dormant de Cambior Inc., ainsi que d?Hydro-Québec, le potentiel réel d?économie énergétique des foreuses portables hydrauliques et électriques par rapport aux foreuses conventionnelles à air comprimé a été évalué pour des roches dures et moles. Ainsi, cet article a pour objectif d faire ressortir ces potentiels d?économie énergétiques. En outre, les résultats pour une mine mécanisée et une autre mine de type filonien, dans lesquelles on retrouve des conditions de terrain différentes, seront présentés. Les résultats montrent un potentiel d?économie énergétique d?environ 70% pour la foreuse électrique et d?environ 50% pour la foreuse actionnée à l?eau. Ces résultats montrent qu?il est possible d?obtenir une meilleure efficacité énergétique par mètre foré. Ainsi, il apparaît maintenant intéressant de poursuivre les travaux de développement des deux technologies pour les applications de forage vertical et de tensionnement des boulons, et de viser à accroitre le taux de pénétration de la foreuse électrique pour le rendre équivalent à celui de la foreuse à air comprimé.

May 1, 2007

By James A. Robertson

"This paper is the result of a continuing investigation begun in 1953 by government geologists and mining companies. Previous work is reviewed and the development of several stratigraphic nomenclatures and correlation schemes is traced, culminating with the interim report of the Federal-Provincial Committee on Huronian Stratigraphy formed in 1966.The stratigraphy, structure and correlation of the Huronian rocks of the Blind River area and the region between Sault Ste. Marie and Sudbury are reviewed. The area is underlain by three Precambrian units: (1) the Archean greenstones and granites, (2) the Huronian sedimentary and volcanic rocks and (3) the post-Huronian intrusive rocks. The Huronian rocks, largely quartzite and conglomerate with greywackes, argillites and carbonates, were laid down in shallow water transgressing over the eroded Archean basement. Thickness and facies changes indicate a northwesterly source, northerly overlap and deposition controlled by basement topography. Polymictic conglomerates, occurring at least at three horizons, represent tillites and are associated with varvites with dropped clasts. These are best developed in the Gowganda formation, which varies from a continental glacial environment in the north to a marine glacial environment in the southeast.There were at least three phases of post-Huronian igneous activity, probably related to several periods or phases of late Precambrian deformation and metamorphism: (1) sills of Nipissing diabase and rather younger diabase dikes; (2) the Cutler Granite and Croker Island Complex; and (3) dikes of Keweenawan olivine diabase.Copper mineralization is associated with the Nipissing diabase. The uranium ores are found in pyritic quartz-pebble conglomerate near the Huronian Archean unconformity, particularly in ancient valleys; they are considered to be placer deposits modified by later events. Uranium production from the Blind River camp to the end of 1966 was 128,160,096 pounds U308 valued at $1,203,840,848 derived from 56,077,179 tons of ore grading 0.11 per cent U308.Within the Blind River and adjacent areas, future discoveries will probably be the result of costly systematic deep-drilling programs accompanied by detailed geologic studies of the type carried out by oil companies and probably computer-oriented."

Jan 1, 1969

The Curtin University Gold Technology Group has been involved in surveying, modelling and optimisation of batch centrifugal concentrator type gravity circuits and CIP/CIL circuits for nearly two decades. The most commonly asked question regarding gravity recovery is, “What is the benefit of a gravity circuit”, which can be hard, if not impossible, to quantify. With the help of the AMIRA P420 Project’s Integrated Liberation Leach Model (ILLM) it is now possible to evaluate the effect of gravity recovery on total gold recovery when changes are made to the grind size, gravity and/or leach/adsorption circuits. This paper demonstrates how the ILLM can be used to determine the net benefit of introducing or modifying a gravity circuit and assess the effect of operating conditions (grind size, coarse gold size distribution, leach residence time, carbon activity, etc.) on plant performance.

Jan 1, 2017