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By Chao Yang, Liguo Tian, Yan Yang

"The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year.This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant.Major modifications and improvements on the SABC circuit are described in the paper, including:1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball.2. Effect of milling operation parameters on milling efficiency.3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput.4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput.With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed."

Jan 1, 2012

By Geoffrey Gilbert

Rossland is in the West Kootenay district; 5 miles north of the International boundary and 4 miles west of Columbia River at Trail. The first claim in the district was located in 1887; but there was little activity until 1890; when the showings that later became important were staked and development began. Production increased rapidly from 1; 800 tons in 1894 to a peak of 360; 000 tons in 1903; and averaged 286; 000 tons for the next 13 years. It declined sharply in 1917; and continued to decline until the closing of the main mines in 1928. Between 1933 and 1941 leasers mined a further 137; 000 tons. Total output has been about 6; 200; 000 tons; with average recovery of 0.47 oz. gold; 0.6 oz. silver; and 1 per cent copper. The total value was $82; 500; 000; of which aboµt three-quarters was in gold; the camp still leads the province in total gold produced. Ninety-eight per cent of the tonnage came from a small compact area worked by four inter-connected mines : the Le Roi (39 per cent); Centre Star (25 per cent); War Eagle (24 per cent); and Josie (10 per cent); all now owned by the Consolidated Mining and Smdting Company of Canada; Limited.

Jan 1, 1954

By E. G. Parker

"Sherritt's zinc pressure leaching process converts zinc sulphide concentrates directly to zinc sulphate solutions and elemental sulphur. Thus, one pressure process step replaces both the roasting and leaching operations of the conventional roast-leach route. In addition, high single-pass extractions eliminate the need for residue treatments to recover unleached zinc. Because pressure leaching produces elemental sulphur, rather than sulphur dioxide, acid plants and smoke stacks are not required, and air pollution control and work-place hygiene are greatly improved. .In 1977, Cominco Ltd. and Sherritt Gordon Mines Limited jointly operated a three-tonne-per-day pilot plant to demonstrate pressure oxidative leaching of Sullivan zinc concentrate and the subsequent separation of elemental sulphur. The process consisted of regrinding the concentrate, continuous leaching at 150°C at elevated oxygen pressures in a four compartment autoclave and the subsequent recovery of elemental sulphur, either in the molten liquid form from a decantation autoclave or as a flotation concentrate. Of the zinc contained in the concentrate, 97% was extracted in 90 minutes, and 96% of the sulphur was converted to the elemental form.Following the successful pilot campaign, Cominco began building the world's first commercial zinc pressure leaching plant. This plant, which was in operation by late 1980, will eventually treat about 25% of Cominco's planned zinc capacity of270,000 tonnes per year.This paper describes the general process principles, the results obtained from the pilot plant and the integration of the process into Cominco's operations at Trail. The application of pressure leaching to a ""grass-roots"" plant is also discussed, and compared with conventional roast-leaching."

Jan 1, 1981

By Linruo Zhao, Qi Yang, Akihiro Sato

TiN coating has a wide range of tribological applications from wear reduction of cutting tools to erosion protection of gas turbine engine compressor components. The performance of TiN coating depends on its microstructure, mechanical properties and adhesion strength which are influenced by the coating deposition process. In this study the effects of cathodic arc deposition conditions on the microstructure, hardness, adhesion and erosion resistance of TiN coating were investigated experimentally. It was found that varying deposition temperature, substrate bias and N2 pressure could derive a processing window in which TiN coating with superior erosion performance can be fabricated.

Jan 1, 2010

By K. Aziz

The solutions to unsteady-state gas flow in a radial system have been reviewed in order to aid in the interpretation of drawdown data. It has been the practice to evaluate the time and rate conversion constants, directly or indirectly, by using reservoir data. This paper presents a method of determining these constants from drawdown data. A simplified approach to the de-termination for the various boundary conditions is presented. An example of a problem which illustrates the use of this theory appears in the appendix. UNSTEADY-STATE FLOW EQUATION The solution of any unsteady-state flow problem involves (1) the continuity equation, (2) the equation of state of the fluid, (3) the equation of fluid motion and (4) the boundary conditions. For the Darcy flow of a gas in the horizontal radial plane, the equation is when the viscosity, compressibility and permeability to gas flow may be assumed constant and the medium

Jan 1, 1963

By G. T. Lapidus, O. J. Solis-Marcial

Currently, ores with high-grades of copper oxides and secondary sulfides have become increasingly scarce, which has encouraged industry to look for alternative raw materials to obtain copper. The problem is that primary sulfides are difficult to dissolve at near ambient conditions. Proposed hydrometallurgical processes have not been implemented beyond a pilot or demonstration scale. One of the principal disadvantages is that the majority of these processes are not viable with ores that contain less than 4% copper. One of the more recently proposed techniques involves the use of organic solvents in the dissolution of copper concentrates with a chalcopyrite content of between 20 and 30%, which has shown high efficiency. The present research explores the ability of this process to leach copper from low grade chalcopyritic ores (<4% Cu) at different temperatures ranging from 20 to 50°C. It was found that depending on the temperature, high percentages of copper were extracted in 40 to 100 minutes, using different oxidants. Additionally, distinct leaching behavior was observed with each oxidizing agent. In some cases, the extraction kinetics adjusted to the diffusion controlled shrinking core model.

Jan 1, 2014

By William A. Price

The objective of this paper is to outline the approaches used in British Columbia to address the challenges posed by metal leaching and acid rock drainage (ML/ARD). Challenges include the large financial costs, the need for site-specific assessments, the large information requirements, the need for mitigation measures to be designed and financed in a manner that permits long-term performance, the lack of long-term operating experience, the ongoing changes in many important processes, the need for pro-active detection and resolution of concerns, difficulties in predicting the potential for ARD or significant metal leaching, the need for new tools, and the multidisciplinary, highly specialized nature of the work. Consequently, mines must be planned, operated and closed in a manner that permits regular review, detailed monitoring and adaptive management. Proper consideration of the challenges involved, including a plan of how all outstanding concerns will be addressed, studies to address areas of significant uncertainty and caution in the absence of the required understanding, should ensure environmentally safe practices in the future.

Nov 1, 2002

By M. J. Brodie

"The decision to proceed with mine decommissioning, generally involves a number of complex and independent factors. These factors, including potential for re-opening, legal requirements, contingent liability, asset depreciation, due diligence, and public relations are discussed in the context of the financial implications on a net-present- value basis. It is concluded that the decision to delay mine decommissioning is commonly not in the best financial interests of the mine operator. Some measures to reduce decommissioning costs and expedite the process are presented.IntroductionThe primary audience for this paper is mining executives, although it should be of interest to all professionals involved in the planning and carrying out of mine decommissioning. Historically, mines were abandoned, not decommissioned. Then, as decommissioning became required, it was assumed that salvage revenue would pay for decommissioning. During the I980s, it became apparent that mine decommissioning costs would exceed salvage revenue for nearly all sites, and that a substantial net cost for decommissioning would be realized for some sites. Throughout this period, the approach to decommissioning has evolved through the sequential addition of measures to meet the increasing regulatory burden. This has resulted in a process in which the elements of decommissioning may not be optimized with respect to each other for the most favourable net present value to the corporation. Additional considerations which are not specific to mine decommissioning, such as environmental policy, due diligence and public relations, may now come to bear on the decision-making process.This paper addresses the issue of mine decommissioning as a three-step process. The first step involves identification and evaluation of all of the issues that relate to mine closure, the most importantof which is the potential for re-opening of a mine. Assuming that it is decided that a mine is unlikely to re-open, the second step is to determine when to carry out the decommissioning work. This aspect is examined through a net present value (NPV) approach. Finally, details regarding who does the work and how the various tasks are divided up must be resolved.Every mine is a unique concentration of minerals at some specific location, hence the development, operation and closure of a given mine must be regarded as a special case. Superimposed on the site-specific considerations are the size, history and financial status of the associated corporation."

Jan 1, 1995

By A. Mellek, M. Pischtschan, M. Perrucci

ABB has received an order for one of the most challenging mill drive projects in its history. With one SAG mill and one ball mill to be added at an iron ore mine in Sweden, the customer’s plant managers wanted to have the most efficient solution for driving their mills but had the budget limitations typically faced by the majority of mining companies during periods of market downturn. To find the best balance between cost of acquisition and highest performance throughout the lifetime of the plant, ABB was selected to deploy a synchronized bypass solution, in which only one drive system is used for two different mills in series. However, being one of the first grinding mills in the world with such a solution was not the only challenge the ABB team faced: The inclusion of some mill application functions - e.g., frozen charge protection, automatic positioning and creeping mode - brought the demands on the engineers to another level. With only one frequency converter and one mill application controller available, the configuration logic and interlocks had to be meticulously designed and thoroughly tested to ensure a smooth and safe startup. The solution offers a footprint reduction and more operator flexibility at a reduced investment as each mill can be run in both directions, and wear on the mechanical components can be greatly reduced due to ABB’s premium ring-geared mill drive (RMD). This paper will describe the details of the project, the configuration developed and the tests performed to guarantee correct software functionality. Mill startup is scheduled for January 2016.

Jan 1, 2016

By H. Hejny

Given the current status of political discussion in Europe about raw materials issues, the sustainable development of the extractive industry and the reduction of its environmental and societal footprint are among the key topics in this discussion. In this context, the European Commission approved the EO-MINERS project (Earth Observation for Monitoring and Observing Environmental and Societal Impacts of Mineral Resources Exploration and Exploitation). The overall aim of EO-MINERS is to bring into play EO-based methods and tools to facilitate and improve interaction between the mineral extractive industry, authorities, and the society in view of its sustainable development while improving its societal acceptability. Developing generic, standardised and reliable EO-based products to monitor the environmental and societal footprint of mining projects is the way chosen by EO-MINERS to improve this interaction, along with the organisation of tripartite meetings gathering all relevant stakeholders. The project uses existing EO knowledge and carries out new developments on three demonstration sites (Sokolov lignite mining area, Czech Republic, Witbank coal field, South Africa, Makmal gold mine, Kyrgyzstan) to further evaluate and demonstrate the capabilities of integrated EObased methods and tools in monitoring the environmental and societal footprints of the extractive industry during all phases of a mining project, from the exploration to the exploitation and closure stages. It contributes providing reliable and objective information about affected ecosystems, populations and societies, to serve as a basis for a sound ?trialogue? between corporate stakeholders, governmental organisations and societal stakeholders. The project already developed a set of consolidated indicators based upon previous knowledge about mining-related issues along with interviews of national, regional, and local stakeholders. These indicators reflect known environmental and societal issues at mining sites as well as the interest of various relevant stakeholder groups. The process described in the EO-MINERS project ? policy assessment > indicator identification > choice of suitable EO tools able to serve monitoring task > monitoring by EO tools > making available objective information for fair dialogue among stakeholders ? is generally applicable to all stages of a mining project. The key to success will be the right choice of indicators addressing the problem and subsequently the right choice of suitable EO tools and finally the willingness of all stakeholders to find a common solution. To this end, the EO-MINERS project organises site-specific ?trialogue? workshops at each demonstrations site, which aim to provide relevant information in adequate quality to the stakeholders as common ground for discussions. Local stakeholders, including mining companies, regulatory bodies, and community representatives are invited to participate in these workshops where the relevance of the developed EO-based products to environmental and societal impact assessment will be discussed. The presentation will discuss results obtained during these trialogue workshops, as well as the success and difficulties and reluctances encountered. The project will further indicate ways and means how the EO products and other project results may be used for monitoring purposes in all phases of a mine.

Aug 1, 2013

By Pierre Antoine Dhaiti, Gilbert Sergerie, Michel Dagbert, Jean-Maurice Brodeur

"Quality of iron ore is generally determined by several factors which can be correlated or independent. Among these f actors, we generally find per cent iron, silica, magnetite or hardness. Forecasting the short- and long-term fluctuations of these f actors in the future pit is an important feature of mine planning in these deposits. Computer simulation provides a realistic answer to these questions. It allows to generate values for the most important quality features of each shovel load with the proper correlations between them as well as between one load and the next being fully reproduced. Then different sampling schemes f or grade control or blending facilities can be examined on the simulated data. The mechanics of the simulation procedure and its potential applications are described in an example.IntroductionThe purpose of this paper is to illustrate the use of in-situ grade simulation in the planning o f the grade control in an iron ore min e. More precisely, given a production unit of given size, we need to know how many samples have to be collected in that unit so that we ca n recognize its grade with a reasonable precision. Conclusions that we would like to arrive at are of the type: with 4 blasthole samples we ca n get the iron grade of a 10,000 ton bloc k with less than a ± 2% Fe error 95% of the time.The approach t hat we take to solve this problem is simulation. We simulate the grade of samples and the grade of the block that contains these samples. We repeat the simulation for hundred s o f blocks. By comparing the sample grade with the block grade in each case, we determine the actual number o f blocks where the difference sample-bloc k is less than a given limit."

Jan 1, 1983

By B. Hoare, H. M. Hill

"SYNOPSISTailings volumes, disposal systems, effects of dam failures, construction materials, and concentrator process water volumes are discussed. Earth dams and tailings dams are discussed in detail. Some of the fundamentals of soil mechanics relating to earth dams are presented. Brief notes on optimization are presented. The development of a triplex meter for earth dam instrumentation is described. The advantages of the hydro-cycloned dam over the spigotted dam are outlined. INTRODUCTIONThe realistic and responsible recognition of the pollution problem, combined with the grossly increased volumes of waste material from large modern mining operations, has emphasized the demand for safe tailings dams at minimum cost.Tailings may be defined as the waste material from a mining operation after the process of concentration in which the minerals have been extracted for commercial use. The present revenue from the Canadian Mining Industry is slightly over $4,000,000,000 per year and it is estimated that the quantity of tailings produced exceeds 300,000,000 tons annually. In many instances, the volume of tailings from a mining operation is greater than the volume of crude ore mined on account of the small quantity of valuable mineral recovered during concentration, and on account of the ""swell factor"" resulting from the processes of drilling and blasting, crushing, and grinding of the crude ore. Some of the larger mine tailings deposits contain over 200,000,000 cubic yards and the associated tailings dams are among the largest man-ma.de structures in the world."

Jan 1, 1970

By S. Eckert, M. Reuter, O. Keplinger, D. Obiso, N. Shevchenko, M. Akashi

We report on laboratory experiments focusing on bubbling phenomena arising from gas injection through a top submerged lance (TSL) in a liquid metal layer. The objective of this study is to reveal the characteristics of the formation and behaviour of the particular bubbles at different gas flow rates and submergence depths of lance. Visualization was performed in the eutectic alloy GaInSn using X-ray radiography. Argon bubbles were injected through the injection positions at three different submergence depths. Essential parameters such as the bubble size, bubble shape, detachment frequency and the two- dimensional gas distribution in the flat vessel were obtained by image processing. The results show that the deep position of the submerged lance causes an asymmetric large-scale circulation inside the fluid vessel. Bubble detachment frequencies were calculated by Fast Fourier Transformation from fluctuations of the image intensity in the vicinity of the nozzle injection point. This frequency does not show strong variations with respect to changes of the gas flow rate and the submergence depth of the nozzle. An increasing gas flow rate results in an increasing two-dimensional projected bubble area and the occurrence of a significant number of small bubbles being trapped by the strong fluid flow in the liquid metal layer. INTRODUCTION The Top Submerged Lance (TSL) process has been an essential component of the metallurgical industry since the emergence of first concepts about 50 years ago (Floyd, 2005). The process, which is characterized by blowing reactive gas through the submerged lance into a liquid bath, was developed mainly for improving the tin smelting process and has been applied for waste treatment or the production of several metals such as copper, lead, nickel and zinc. The productivity of the reactor is determined mainly by the efficiency of the chemical reaction between the gas or solid particles and the liquid. To achieve a high efficiency requires good exchange between the gas-liquid phase and therefore a large interface area. The efficiency changes greatly with the number and size of bubbles injected from the nozzle and the extent of splashing on the free surface. The degree of turbulence in the bath plays a decisive role here. For the reason, the design of an efficient TSL process requires a profound knowledge of the fluid dynamics especially for complex multiphase flows.

Jan 1, 2019

By Michael R. Brown

A facilities success or failure of doing well during a regulatory inspection is typically measured by the number and type of citations that result, and financial liability resulting from those citations. The success of a facility during an inspection depends on several factors including, the preparation prior to an inspection, behavior and activities during and inspection, and finally, action taken following the inspection. This paper contains suggestions for improving inspection results and establishing an attitude of compliance at manufacturing and mining facilities.

May 1, 2002

By J. B. Mawdsley

"The Red Lake Gold Shore mine is 4/5 mile west of the town of Red Lake, Ontario, and a mile northwest of the Howey mine. It came into production in August 1936, and in a little over 2 years produced 21,099.58 oz. gold from 83,949 tons milled.An investigation of this deposit was made by the writer during parts of September and October, 1937t. The geology of the deposit is also discussed by H. C. Horwood(2) , and the characteristics of the ore were investigated by the Bureau of Mines, Ottawa (1).The orebodies are pipe like and close together, in a north-northwesterly trending zone of dykes, veins, and shear zones in a granodiorite stock, just south of a pronounced valley with a trend of N.65°E. believed to lie along a strong shear zone and fault . The dykes, veins, and mineralization are believed to have been successively emplaced along structures having three general trends and that were due to compressive stresses that alternated, at least four times, from west of north to east of north. In common with many other gold deposits, the gold mineralization here occurred late and followed the last east-of-north stresses.WALL-ROCKSThe mine is within the Dome stock, % mile from its southeast margin. Near the mine the rock is a pink hornblende-biotite granodiorite, grading within short distances, but not abruptly, into a dark grey variety. Near the workings at least, scattered small inclusions form about ½ to 5 per cent of this body. Most of them are fine-grained, angular, or partly rounded, greenstone fragments, but some have been partly granitized and feldspar has been developed in them."

Jan 1, 1954

By D. Satish Kumar, D. Mazumdar

"95% bulk mixing times in three different size water model ladles of a 140 T cylindrical shaped , dual plug ( located diametrically opposite at mid bath radius position) stirred, industrial ladle were determined experimentally with and without an upper buoyant phase. Based on dimensional analysis and a regression of the experimental data and, it was shown that in the inertial and gravitational force dominated flow regimes, 95% bulk mixing times for a slag-less situation can be described via:[equation]Parallel to this, a large number of experiments were also carried out in one of the water models (D=0.30m) to quantify the influence of an upper buoyant phase on mixing. These indicated that mixing time, operating variables and thermo-physical properties of the upper phase liquid can be correlated via a dimensionless relationship of the type:[equation]in which, Q is the ambient gas flow rate, L is the depth of liquid , (AL) is the slag layer thickness and 6 and t are respectively the surface tension and viscosity of the upper phase fluid The dimensional analysis, regression of experimental data as well as the adequacy of the proposed correlations are discussed in the text."

Jan 1, 2004

By G. R. Peeling

The Mining Association of Canada launched the Towards Sustainable Mining initiative in 2004. TSM&apos;s goal is to improve the mining industry&apos;s performance by aligning its actions with the priorities and values of Canadians. The initiative currently includes performance indicators for four areas: tailings management, energy use and greenhouse gas management, external outreach and corporate crisis management planning. Over the past year, the association has been designing a performance assessment and verification system for these performance areas, as its members prepare to move external verification of their performance in 2007. The initiative and its evolution, as well as the challenges faced in developing a verification system applicable to an entire sector will be examined.

Jan 1, 2007

By D. K. Sarkar, Ying Huang

"Superhydrophobic thin films were fabricated on aluminum alloy substrates by chemical etching followed by passivation with organic acid molecules; (ii) electrophoretic deposition (EPD) of functionalized ZnO nanoparticles and (iii) electrodeposition of organic-inorganic composite materials. The physical and compositional analyses of the deposited thin films were characterized by SEM, FTIR, XRD as well as contact angle goniometer. The contact angle and surface roughness of the superhydrophobic surfaces prepared by the chemical etching process were found to be 156° and 2.29 µm, (ii) by the EPD process were found to be 155° and 4.54 µm and (iii) by the electrodeposition process were found to be 159° and 7.11 µm, respectively.The corrosion properties were analyzed with both polarization and electrochemical impedance spectroscopy (EIS) in NaCl aqueous solutions. The results demonstrate that the superhydrophobic thin films on aluminum alloy substrates display better anti-corrosion behavior than the as-received aluminum substrate. The comparison of results pertaining to the compositional and corrosion properties of these thin films on aluminum will be discussed in this work.INTRODUCTIONSuperhydrophobicity is defined as a surface property which provides non-wetting characteristics with a water contact angle larger than 150°. It is observed that the creation of certain micro-nanoroughness structures promotes the entrapment of air in the spaces of the rough surface morphology. In addition, lowering the surface energy helps to reduce the affinity of water drops to the surface, thereby weakening the water-surface interaction. Recently, various fabrication methods for superhydrophobic surfaces have been explored (Sarkar, 2010, Huang, 2010, 2011, 2013, 2015a, 2015b), such as the sol-gel process (Brassard, 2011), plasma treatment (Marchand, 2013), chemical vapor deposition (Zheng, 2009), chemical etching (Saleema, 2011), electrodeposition (Ying, 2011) and electrophoretic deposition (EPD; Huang et al., 2015b)."

Jan 1, 2016

By Akihiko Nishiyama

Unmanned construction technology used for remote control operation of construction machines has some problems to solve compared with manned operation of construction machines, such as fatigue due to long-term operation or decreases in operational efficiency. To solve these problems, we recorded the viewpoints of operators in both manned and remote control operation and analyzed the differences. This paper reports on our discussion of improving the operability of remote control operation based on the analysis results.

Aug 1, 2013

By Zainelabdin Khalid Zainelabdin Elfaki

The influence of partially replacing cement with marble waste on the workability and compressive strength of concrete bricks was investigated. Three replacement percentages, 10%, 20% and 30% weight marble waste, were used with different curing times of 7, 14 and 28 days. Two specimens were prepared for each percentage and curing time. For this study, marble powder from the Mining House Company in Saudi Arabia was used. It was observed that the replacement of cement in Concrete brick with marble waste enhanced the loading strength and the workability of the prepared concrete bricks. It was also observed that 20% replacement of cement with marble waste was the best replacement percentage compared to the other replacement percentages tested. Marble waste from manufacturing companies, either in powder, sludge or slab form, has negative impacts on the environment. In contrast, reusing marble waste has both economic benefits (i.e., selling the marble waste) and lessening the need for raw resources.

Jan 1, 2014