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By M. O?Driscoll

The tide has turned. Developments in China that have continued to unfold over the last four years or so have now reached a point where the supply market dynamics of certain industrial minerals have changed significantly. No more is this sea change better exemplified than by the supply market for magnesite, and in particular, its processed derivative grades of dead burned magnesia (DBM), caustic calcined magnesia (CCM), and fused magnesia (FM). But what has compounded the barrage of influencing factors impacting this sector, which include the widespread effects of energy and freight cost increases, has been rising demand from certain end use markets. Clearly, the magnesia market is experiencing bittersweet conditions. But those western producers which have monitored and responded to this market transformation, stand to taste success in the near and medium future. REVOLUTION IN WORLD SUPPLY STATUS In essence, while China, as host to a wealth of magnesite resources in Liaoning province, remains a huge producer of magnesia, its supply dominance on the global magnesia market has been considerably weakened. In future, it will mainly aim to supply domestic, and to some extent east Asian markets. Magnesia consumers outside China are now scrabbling for alternative, ?western? sources of supply. At the same time, magnesia producers outside China that weathered the storm of low cost Chinese DBM and FM imports flooding their regional markets for the last 20 years (and many did not), are busy investing in production capacity increases to meet not just demand from falling Chinese supply, but also demand from end use markets which is picking up. And it is not just a matter of expanding capacity of existing magnesia product lines. In the face of plentiful lower cost DBM and FM substitutes from China over the last couple of decades, many western magnesia producers started to switch their focus to the non-refractory markets (eg. environmental, specialities) which promised lucrative opportunities (and still do) and crucially, a lessening of sales revenue dependence on the DBM refractories market. Now we have the likes of Baymag (Canada), Bommag (Serbia/Turkey), and Kumas (Turkey) not only expanding capacities but seriously considering diversifying into DBM and FM production. Perhaps DSP (Israel), having ceased its famous high purity DBM activity as recently as 2005, might even reconsider a return to the ?other side?. But it?s not all DBM and FM. The CCM and specialities markets are also demanding a response, and so Baymag, DSP, Martin Marietta (USA), Premier Chemicals (USA), Qmag (Australia), MGR (Spain), and Magnifin (Austria) are also stepping up to the market on the non-refractory side. From most accounts, the situation with regard to Chinese supply has been described as one of turmoil, with prices rising, leading to improving opportunities for western producers. The majors are conducting huge expansion programmes, such as Qmag, Magnezit (Russia), and the new look Magnesita (Brazil). Even smaller players such as Causmag (Australia) and Dalmia (India) are looking to increase production. In short, the western magnesia supply sector is witnessing a landmark event in capacity investment and market share penetration as China?s previously dominant role begins to weaken (for a review of western capacity expansions see Industrial Minerals, September 2008, p.28). MERGER & ACQUISITION ACTIVITY Another response of course has been a raft of mergers and acquisitions in order to secure resources and supply outside China. These have included private equity groups taking over Magnesita and Qmag; Imerys entering the FM business through UCM; Peñoles further consolidating the electrical grade FM market by acquiring Minco; Martin Marietta acquiring Morton Salt?s Specialty Magnesia Group; Bomex entering the market through Calmag (now Bommag); LWB acquiring Magnesita; and Magnezit?s pursuit of Slovakian magnesia, with Slovmag aboard while currently wooing SMZ. Interestingly, RHI has gone ?the other way?, and has invested in a state of the art joint venture operation at Dashiqiao, Liaoning, with which it aims to secure high quality feedstock for its Chinese refractory plants. Tata Refractories Ltd has announced intentions to follow suit, and other majors, such as Qmag are known to be interested in seeking options. Naturally, there is now renewed interest from several parties in the idled 50,000 tpa DBM/10,000 CCM Jormag facility, Jordan, and the commercially undeveloped Zhargat project, Saudi Arabia. Elsewhere, there will no doubt be suitors for stakes in SMZ, in Slovakia, and Magnohrom, in Serbia, whose respective ownerships are on the block. THE ?CHINA FACTOR? The ?China factor? has been key to magnesia?s market change, and has significantly influenced prices and availability of material to global markets. Resources & production China hosts the largest share of the world?s magnesite deposits, accounting for 26% or 3,319m. tonnes of predominantly sparry magnesite (followed by North Korea, 24%, and Russia, 22%; Wilson 2008). China accounts for 44% of total world magnesite mined (19m. tonnes in 2007) and 50% of the total world magnesia produced (8.2m. tonnes CCM, DBM, FM; Wilson 2008). Russia follows China at 13% of magnesia supply, illustrating China?s dominance of magnesia production. Apart from one producer in Shandong province, central eastern China, the country?s magnesite resources and production are concentrated around the cities of Haicheng and Dashiqiao in Liaoning province, north-east China. Although there are also producers in the Xiuyan district of south-east Liaoning, the Haicheng-Dashiqiao Magnesite Belt hosts the majority of producers. In total these may number 200-300 of large,

Jan 1, 2009

By J. W. Craven, M. Katom, K. M. McCaffery

At Ok Tedi, ore type and SAG feed size distribution vary widely and frequently. This makes control of the SAG mills by application of the power/pressure relationship difficult. Power logic has traditionally been conservative due to power spikes associated with rapid size distribution changes. A new expert system was installed in early 2000. The system incorporates multiple state fuzzy logic to deal with frequent and radical ore type and size variations, along with monitoring of motor temperatures. A short term power spike no longer warrants immediate radical action. This has resulted in increased mill throughput and improved circuit stability.

Jan 1, 2001

By J. Brooks

The use and application of shotcrete for ground support in the Asia Pacific Region is as diverse as the countries that make up this region. This paper will attempt to describe the many methods used on selected projects within that region. The project description(s) will include project logistics, equipment, mix design, products and application methods utilized along with specifications and performance results (where available). The author will attempt to reach a conclusive opinion on the success, or nonsuccess, of the various shotcrete methods employed and the development of shotcrete within the Asia Pacific Region.

Jan 1, 1999

By J. F. Mack, P. R. Michael, J. M. Shapaka, S. J. Self, M. W. Richmond

"On October 11, 2000, an estimated 306 million gallons of water and coal waste slurry drained from an impoundment in Martin County, eastern Kentucky into an adjacent underground mine. Approximately 230 million gallons of the water and slurry discharged from two underground mine portals and affected over 75 miles of streams in Kentucky and West Virginia. In response to this and several other similar events, the U.S. Office of Surface Mining Reclamation and Enforcement (OSMRE) commissioned an oversight study that evaluates how well state and federal regulatory programs established under the Surface Mining Control and Enforcement Act are ensuring that impoundment operators are minimizing the potential for impoundment-basin breakthroughs. The study focuses on slurry impoundments constructed in the hollows of Appalachia where numerous coal seams and steep topography combine to result in a large number of mined seams intersecting and underlying impounding facilities. Factors under consideration include: (1) full accounting of all mineable coal seams intersecting and underlying the impoundment; (2) identification and accurate location of underground mines close enough to the impoundment to potentially affect its stability; (3) assessment of the stability of coal barriers between the impoundment basin and adjacent mines, and stability of roof rock and pillars in mines subjacent to the structure; (4) determination of the flowability of the impounded slurry when expanding or undermining the facility are being considered; and (5) measures undertaken to reduce breakthrough potential when necessary. The oversight study began in 2012 after program-evaluation criteria were defined in an OSMRE technical position paper. The study is scheduled to be completed in 2017. BACKGROUND The Surface Mining Control and Reclamation Act (SMCRA) authorizes the disposal of coal mine waste by constructing a coarse coal mine waste embankment across a valley and pumping the fine coal mine waste (slurry) into the resulting basin (Figure 1). A concern shared by many engineers, geologists, and mine inspectors familiar with coal mine waste slurry impoundments is related to the common occurrence of underground mine workings adjacent to or beneath the impoundment: the potential for slurry “breakthroughs” into mine works and subsequent breakouts into the surface waterways (Figure 2). On October 11, 2000 a combination of coal refuse slurry and water from the Big Branch impoundment in Martin County, Kentucky broke through into an underground mine and subsequently discharged into the receiving streams. The location of the point of breakthrough, pathways of slurry/water flow within the mine workings, and two points where the liquid exited the mine are shown in Figure 3. An estimated 306 million gallons of water and coal refuse slurry drained from the impoundment into the adjacent underground mine. Approximately 230 million gallons subsequently discharged from the underground mine at two portals."

Jan 1, 2015

Like the Summer Olympics and U.S. presidental elections, MINExpo comes along once every four years. More than 35,000 people attended the last MINExpo and there is talk that there will be more this time. Just about every company that has anything to do with mining, 1,822 to be exact, will exhibit their wares at the show, but it is the ones rolling in the massive equipment that make MINExpo the show that it is. The following is a glimpse at some of the companies and equipment that you can expect to see at this year?s MINExpo.

Jan 1, 2012

By Ross Glanville

The Optimum Production Rate (OPR) is one of the most important parameters in the evaluation of a mineral deposit. The OPR cam also be expressed as the Optimum Mime Life (OML) in years since the expected mime life is determined by dividing the OPR per year into the estimated ore reserves. Unfortunately, very little time and effort has been directed towards the determination of the OPR. Instead, "rules of thumb" are often applied to select a mime life without due consideration of the economic implications of such a selection. A "justification" for a particular production rate is often based on a pre-conceived arbitrary requirement for a mime life of 5, 10, or 15 years, for example. In this paper it is demonstrated that such arbitrary selections for high-grade/low¬-tonnage mines (such as many underground gold/silver deposits) often lead to sub¬optimal results. In fact, am apparently uneconomic deposit at am arbitrary production rate may be economic at the OPR. Consequently, investment opportunities may be overlooked if one analyzes mime' properties based on arbitrary production rates.

Jan 1, 1984

By R. Todd Swinderman

"Higher production demands across all bulk handling segments require increased efficiency at the lowest cost of operation, in the safest and most effective manner possible. As conveyor systems become wider, faster and longer, more energy output and more controlled throughput will be needed. Add an increasingly stringent regulatory environment and cost-conscious plant managers must closely review which new equipment and design options align with their long-term goals for the best return on investment (ROI).There are primarily two separate market segments using conveyor belts. One is in process industries such as food, chemicals, paper and powders. Handled in relatively low volumes, the bulk materials that enter these processes are generally of a consistent size and quality. The other market includes mining, coal handling and cement, where the bulk material’s quality and size vary, and the volumes are typically much greater. While both segments face similar issues with safety and environmental control, the properties of the materials handled and the volumes transferred suggest different approaches, with one thing in common: increased belt speeds requiring modern equipment upgrades.Safety at higher belt speedsWith companies recognizing that safety does indeed pay, safety is likely to become a new source of cost reduction. The percentage of mines and processing facilities with a robust safety culture are likely to increase over the next 30 years to the point where it is the norm, not the exception. In most cases, with only a marginal adjustment to the belt speed, operators quickly discover unanticipated problems in existing equipment and workplace safety. These problems are commonly indicated by the larger volume of spillage, increased dust emissions, belt misalignment and more frequent equipment wear or failures."

Jan 11, 2018

By Steven W. Hunt, Isabelle Lamb, Steven B. Fradkin

Groundwater control is generally an important consideration and significant source of risk during most tunneling projects. Proper baselining of groundwater conditions requires: 1) a thorough understanding of the geological environment; 2) a focused site investigation; 3) identification of construction and adjacent property damage risks associated with inflows and short and long term piezometric level changes; and 4) consideration of contractual issues including restrictions on means and methods and pay items for associated work. This paper provides an overview of groundwater baselining issues and risks based on selected design studies and construction case histories.

Jan 1, 2005

By D. M. Jepsen

One of the first things we tell a potential new client is that they have only one chance to make a first impression with an Aboriginal community; all future communications and engagement will be predicated on that first impression. The key components of this most critical meeting are not your power point, your maps, or your draft plan for development ? they are instead a genuine, evident and clear demonstration of a sincere desire to develop a positive relationship that is based upon respect, and consideration and understanding of local communities and their interests, needs and desires. Relationship building is the foundation of proactive and positive consultation and accommodation with Aboriginal communities and the tone is set with the first meeting. C3 has refused more clients than we have accepted due most often to the fact that relationships between the company and the Aboriginal community have already devolved into a tense and toxic scenario. Land access and tenure certainty for exploration and mine development is critical to the foundation of a healthy, sustainable and environmentally and economically sound mineral exploration and mining sector. Without certainty confidence to invest in mineral exploration will be severely eroded. We all understand that substantive investments in exploration are required to increase the possibility of discovering, defining and developing new mines. The development of positive relationships based on a shared commitment of understanding, mutual respect and trust by Aboriginal Peoples and the mineral sector can provide the required business certainty and deliver social and economic benefits for local Aboriginal communities.

Jan 1, 2012

By B. Oraee

Tunnels as any other structures are affected by different loads and stresses. Generally, the loads on tunnels consist of both static and dynamic loads. These loads must both be considered in the tunnel design process. In this paper, the stability state of Jiroft water-transform tunnel is evaluated. Firstly, the in-situ stresses and then using Kirsch?s equations the induced stresses due to static loads in walls and crown of tunnel are calculated. Consequently, the strain caused by probable earthquake without considering the interaction between the concrete lining of tunnel and rock mass using seismic analysis is calculated based on free-field deformation. When the strain is determined, the simplified method of closed-form solution, Wang?s equations and Penzien?s equations are used to estimate the applied forces on the tunnel due to earthquake such as axial force and bending moment on a tunnel section taking into account the interaction of the tunnel concrete lining and rock mass. Results of this study show that the loads applied to the tunnel as a result of earthquake waves can be affect the stability of underground structures, especially long structures such as tunnels.

Jan 1, 2011

By Colin Lawrence

The Port of New York and New Jersey is one of the most heavily used transportation arteries in the world, handling nearly 40 per-cent of the North Atlantic shipping trade and directly providing nearly 230,000 jobs to the local economy. In 2004, $100 billion worth of consumer goods moved through the port. To accommodate future cargo volumes in the port, which are expected to double over the next decade and possibly quadruple in 40 years, deeper shipping channels are needed to provide access for a new generation of cargo mega-ships with drafts exceeding 13.7-m (45-ft) when loaded. Current channels within the harbor range in depths up to 13.7-m (45-ft), thus preventing carriers from using these larger ships, or requiring significant reductions in cargo to achieve lesser drafts to operate safely within the harbor. As part of the Harbor Deepening Project, the Anchor-age Channel would be deepened to 15.2 m (50 ft) below mean low water (MLW), for a length of 5,790 m (19,000 ft). The New York City Department of Environmental Protection (NYCDEP) owns, operates and maintains two existing water siphons in the harbor. Due to their shallow depth, both existing siphons must be relocated before dredging of the Anchorage Channel can be completed. Tom Costanzo, manager of capital programs for the Port Authority of New York and New Jersey (PANYNJ), says that ?While the re-location of the existing siphons under the Anchorage Channel is vital to the success of the deepening program, it is also a story of cooperation among key agencies at different levels of government resulting in improvements that will benefit the people of this region greatly.?

Jun 1, 2010

By N. L. Dorset, K. L. Heasley

Unfortunately, mining and mining accidents have gone hand-in-hand since man first started to extract ore from the ground. In the first published treatise on mining, De Re Metallica, Georgius Agricola (1556) stated that cold, water, dust, stagnant and foul air, roof falls, falls from ladders and demons all caused injury and death in the mines of his day. Although demons are no longer considered a cause of accidents in modern mining, the other factors remain with us still. The United States government started keeping track of fatalities with the establishment of the federal Bureau of Mines in 1910. Successor agencies, such as the U.S. Mine Safety and Health Administration (MSHA) continue to track fatalities today. Looking at the records, it can be seen that coal mine fatalities dropped from 2821 in 1910 to only 27 in 2004. The reduction in fatalities and injuries didn’t “just happen.” It took concentrated effort from the entire mining industry: miners, supervisors, safety officials, mining inspectors and mining researchers. But first, specific hazards must be identified before they can be corrected. In past, coal mining accidents have been analyzed by: type (roof fall, electrical, etc), mine attribute (location, seam height, etc.), and aspects of the mineworker (work experience, job classification, etc). Much of this research helped to direct the industry’s attention to where additional vigilance and safety training was needed. No doubt this directed effort has led, at least in part, to the decrease in coal mining fatalities. This paper takes a novel look at coal mining fatalities: it examines the risk of fatalities based on how long the mine has been open.

Jan 1, 2006

By J. H. Tu

The technical paper correctly points out that the kriging variance is not a good measure of the uncertainty of the estimated (i.e., kriged) value of individual blocks. The authors claim that their proposed jack-knife method, which is a rekriging of each block by eliminating, in turn, one sample from m the original sample set and then taking the average of the rekriged estimates, not only gives good block estimates, but the resulting jackknife kriging standard deviation is a useful indicator of the "true uncertainty associated with block estimates." However, they immediately abandon the idea of using the block-by-block standard deviations, reasoning that these standard deviations are not independent and that there is no easy way to utilize them. There may be another reason for not using them. The jackknife standard deviations for individual blocks given in their example are mostly in the range of 0.004 to 0.005 oz/st (0.14 to 0.17 g/t) with only one block having a high value of 0.012 oz/st (0.41 g/ t). These individual block standard deviations are as low as the jackknife standard deviation for the mean grade of the entire shape, i.e., 0.0041 oz/st (0.14 g/t). Do they represent the "true uncertainty" .of the individual block estimates? Could the authors explain this? In a global shape consisting of a large number of blocks, any given sample will affect the kriged estimate of only those few blocks within its vicinity. This is the rationale for the authors' selective rekriging, making the jackknife algorithm more efficient. On second thought, why not do away with jackknifing altogether? Just cumulate and normalize, if necessary, the kriging weights of each sample used during the ordinary block kriging process, and then compute the global variance from these kriging weights and their respective sample grades? After all, isn't the global mean grade nothing but the weighted average of the samples used in the estimation? Reply by G.S. Adisoma and M.G. Hester The jackknife is one of the many tools in a practitioner's toolbox to solve estimation problems. The strengths of the technique lies in its simplicity, i.e., it uses the concept of mean and standard deviation and the fact that it can be easily combined with other tools, in this case kriging. Because the jackknife kriging (JK) estimate is also the mean of the pseudovalues, the JK standard deviation is attractive just as the standard deviation of the mean explains the variability of the data. The difference is that the pseudovalue calculation in jackknife kriging uses the ordinary kriging (OK) weighting scheme instead of simple arithmetic averaging. The data used to illustrate the jackknife technique in the paper con¬sist of high values that are roughly three times the low values. The resulting JK estimate of the block grades show that the highest estimate is roughly twice the grade of the lowest estimate. The contrast between the low and the high estimate is more evident in the JK estimate than in the OK estimate, even though the mean grades of the blocks for the two estimates are very similar. Nonetheless, in this paper, we are concentrating more on the need for a more realistic measure of uncertainty, or precision, for the estimate. Unlike its OK counterpart, the JK standard deviation of the blocks clearly reflects the original data variation. The highest JK standard deviation of the blocks is three times its lowest value. This follows our intuition that, when the samples used to estimate a block is more variable, the resulting estimation variance (or standard deviation) should be higher than the case where the samples are more uniformly valued. However, block-by-block standard deviation or variance is of little practical value in reserve estimation and classification, as well as in mine planning. One is usually more interested in quantifying not the variance of the individual block estimate, but the uncertainties associated with a much larger dimension, such as the minable reserve. Thus, the thrust of the paper is to find a simple way to obtain a single estimation variance or standard deviation associated with the reserve grade estimate. The discussion by J.H. Tu did not mention how one would obtain the global variance from the OK weights and the sample grades. As a technique that offers a data value-based measure of uncertainty for its estimate, the "leave-one-out" jackknife fills this need nicely through the block kriging shortcut approach described in the paper. Note: The first column and the last two columns of Table 3 in the paper should have contained a single number each, namely, an OK estimate of 0.0317, a JK estimate of 0.0333 and a JK standard deviation of 0.0041 oz/st, respectively, for the shape, as are obvious from the text.

Jan 1, 1997

By Satya Harpalani

The four most important parameters controlling the flow of gas in coal are the gas content, permeability, diffusion coefficient and cleat characteristics. Estimates of these and, more importantly, a knowledge about the variation in their values over time are required for simulation of long-term gas production. This paper describes experimental techniques to determine each of these, along with their time dependency, under simulated in situ conditions. It is shown that the permeability, diffusion coefficient and the cleat aperture values are not constant as usually assumed to be. There is a significant variation in their values as a result of changes in the microstructure of coal associated with release and flow of gas.

Jan 1, 1995

By J. Weng

The equations of heat conduction are numerically solved for two kinds of artificial freezing- mechanical freezing and liquid nitrogen freezing. A two dimensional finite difference model simulating the freezing field is developed. The procedure introduces a way to simulate the effect of latent heat released when water transforms from liquid to solid. The procedure also produces a way to calculate the harmonic mean of heat conductivity used when dealing with heterogeneous material. The theoretically derived temperature distributions in frozen soil are given and compared with measured data. An analysis is made on the thermal design in shaft freezing. The average temperature of frozen soil is calculated by using numerical integration. The regularity of development of frozen soil radius is revealed and given in an appropriate mathematical model.

Jan 2, 1984

Invensys’ recently introduced Field Device Manager for Foxboro I/A Series distributed control systems provides the industry’s first solution that takes advantage of both the latest Enhanced Electronic Device Description Language (Enhanced EDDL) and FDT technologies. This combination provides comprehensive lifecycle support to configure, calibrate, commission, diagnose and optimize the performance of any vendors’ foundation fieldbus device. The I/A Series Field Device Manager enables users to take advantage of any EDDL, Enhanced EDDL and/or FDT host deliverables supplied by the device vendor.

Jan 1, 2007

By D. H. Horswill

Red Dog, the world’s largest zinc mine, is located ninety miles north of the Arctic Circle in northwest Alaska on lands owned by the Inupiat Eskimo organization called NANA. NANA received a subsurface title over this resource as part of their settlement lands under the Alaska Native Claims Settlement Act and subsequently entered into a Lease Agreement with Cominco in 1982. Cominco, an international mining company focused on zinc, built and operated the mine. NANA’s principle objective in the development of the mine was to have it contribute to the development of sustainable communities within their traditional region. This meant creating job opportunities in a modern economy while preserving the traditional subsistence lifestyles. Preservation of their culture, language, and traditions are as important to the NANA people today as they were through ages past. The principles of sustainable development – matching economic, environmental, and social goals through continuous communications and high commitment to efficient and effective operations – have been core values for the Red Dog Mine from the beginning. This paper will describe how a large mining operation in a remote corner of the world has been able to contribute toward sustainable development in that region.

Jan 1, 2000

By G. T. Lineberry, L. Adler

Due to safety-imposed constraints on clearances for mobile bulk handling equipment, it is necessary to optimally select a unit based on speed and size. The unit cannot be both large and fast. Since output is proportional to both size (or capacity) and speed, the combination must be carefully examined to maximize output. A simple graphical procedure and a calculus-based solution are presented to accomplish this. While the procedure applies to all mobile bulk handlers, as an example of the solution technique, attention is focused on shuttle cars. Background Major variables To fully define a bulk handling problem, the conditions, equipment, and activities must be characterized. The conditions and activities, when lumped together, are termed "encumbered space," since they "act to impede motion, as with a burden" (Lineberry, 1979). The insertion of mobile bulk handling equipment into what is already a difficult set of conditions and activities compounds the state of encumbrance, as limited space is competed for by many normal and life support systems. Long (1972) recognized the effects of design criteria, including road width, on haulage vehicle speed and, therefore, on production. Velocity -clearance curves Velocity-clearance curves are either available or can be constructed in the field. A preliminary set of curves for average conditions and activities is shown in Fig. 1, where clearances are only for the side of the vehicle (Lineberry and Adler, 1984). These curves set the safe speed limits for a vehicle operating at given clearances, under given conditions and activities. When feasible, velocity-clearance curves should be constructed through field measurement and observation. Curve construction should also consider haulway roughness, distances, and operator skill, as well as loading and dumping characteristics. It should be noted that haulage capacity determination is a total systems problem, not one just dependent on velocity and clearances. Production requirements and company capabilities also influence capacity determination.

Jan 10, 1985

By John W. Shield

Oxide gold reserves are being rapidly depleted, especially in regions with long histories of gold mining, such as the Black Hills of South Dakota. However, these districts often have substantial additional deposits, where gold is refractory. It is not amenable to traditional cyanide extraction due to the presence of sulfide minerals that encapsulate or otherwise preclude the economic extraction of the gold. Several technologies have been developed to render refractory sulfide deposits amenable to traditional cyanide processing. These include roasting and pressure autoclaving. Unfortunately, these oxidation processes require substantial capital investment and incur significant operating costs. Microorganisms that obtain energy for their life processes by the oxidation of iron sulfides can be used to treat gold-bearing refractory sulfide minerals. As the bacteria convert the sulfide to sulfate, they expose any gold associated with the sulfide matrix. This makes the gold amenable to cyanide extraction.

Jan 1, 1996

By D. L. Watson

In spite of the deflationary state of the minerals business today, there will be opportunities for those who can fulfill future needs. Since there are abundant supplies of ores and fuels to keep prices down, at least in peacetime scenarios, future needs may be as much political and social as technical and economic. Engineers and economists will develop new and innovative ways to find, mine, process and pay for mineral deposits. Pressure from governments and non-governmental organizations and the public will combine with market forces to provide opportunities for highly competitive, risk-taking enterprises who can leverage the qualities of their orebodies and employees by being good neighbors and partners.

Jan 1, 2000