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By David M. Spatz

Team, as defined by Katzenbach and Smith (1993), is a small number of people with complementary skills who are committed to a common purpose, performance goals and approach for which they hold themselves mutually accountable. As the mining industry searches for new ore discoveries increasingly under post-mineral cover, the process of mineral exploration has taken us from prospector to geologist to multidisciplined explorer to multi-disciplinary team. Multidisciplinary exploration techniques have improved in terms of sensitivities and penetration and more than ever before each technique requires specialists with appropriate training and skills to process data and interpret results. To produce a quality product, specialists must collaborate openly and honestly in an atmosphere where the collective result takes into account the knowledge and expertise of each individual and the relationships between all pertinent data sets.

Jan 1, 1998

By Kenneth J. Reid, Marian S. Stachowicz

A preliminary evaluation of a new in-stream particle size analyzer has been carried out using materials obtained from a taconite plant in Northern Minnesota. Results are reported for bench scale, pilot scale and full scale tests, the latter being carried out in a taconite plant concentrator. The unit employs a novel scanning laser microscopy principle and details of the equipment configuration and operating principles are presented and discussed. Data acquisition is via an eight channel digital electronic system and particle counts are collected on the basis of reflected light pulse time intervals which are a direct measure of particle size. Output is available as an eight point individual or cumulative size distribution or as computed averages. The practical aspects of sample point location and flow requirements for reproducible results are outlined and discussed.

Jan 1, 1990

By K. A. Natarajan, K. Karthiga Devi

"A biodegradable flocculant was produced during growth of Bacillus megaterium. The major component of the bioflocculant was found to be a polysaccharide composed of some proteins. Fourier transform infrared (FTIR) spectra analysis revealed the presence of carboxyl and hydroxyl groups in the bioflocculant, and thermal characterization by differential scanning calorimetry (DSC) showed the transition and crystalline melting point at 90-105°C. The effects of bioflocculant dosage and pH on the flocculation of mineral suspensions were evaluated. The bioflocculant exhibited good flocculating capability on mineral suspensions and achieved flocculating efficiencies of 90 percent for kaolinite and 85 percent for hematite suspensions at a dosage of only 5 mL/L. The maximum arsenite removal was found to be 90 percent at a bioflocculant dosage of 2 g/L, which is better than traditional chemical flocculants. This study demonstrates that microbial bioflocculants have potential for application in environmental cleanup, such as in the flocculation of mineral fines and in the remediation of solutions that contain toxic heavy metals.IntroductionBioflocculants are biopolymers produced by microorganisms during their growths. The predominant components of a bioflocculant are extracellular polymeric substances such as glycoprotein, protein, cellulose and nucleic acid (Salehizadeh and Shojaosadati, 2001). Bioflocculants have gained much wider attention due to their biodegradability and safety. In recent years, the study of bioflocculants has attracted wide attention. Bioflocculants can be nontoxic, harmless and eco-friendly. Normally, they exhibit different functional properties, serving as stabilizer, dispersant or thickener. Among these properties, flocculation is of major interest. For example, Phormidium sp. strain J-1, isolated from a drainage channel, exhibited excellent flocculation activity for bentonite particles in liquid suspension (Fattom and Shilo, 1984). A protein bioflocculant produced by Rhodococcus erythropolis could efficiently flocculate suspended solids while losing their flocculating activity by enzymatic digestion (Kurane et al., 1994, Takeda et al., 1991). Klebsiella sp. strain S11 screened from activated sludge was unable to flocculate without the addition of calcium chloride (Dermlim et al., 1999)."

Jan 1, 2015

By D. N. Madge

A survey is given of production scheduling systems currently in use or contemplated for future use in Cominco operations. Emphasis in this presentation is made on the chain of decisions that are made with the help of mathematical programming models. Some attention is devoted to the structural properties of the models.

Jan 1, 1966

By Allan J. Breitenbach

Heap leach operations provide a low-cost method for recovering gold, silver, and copper metals from low grade ore materials. The processed ore materials are stacked in controlled lifts on a lined pad facility for heap leaching. A controlled barren solution is applied to the heap ore surface by sprinkler or drip emitter irrigation, and ore metals are leached into the solution for collection and extraction in plant process facilities. The leach pad and solution collection facilities are lined with impervious materials for containment of all process solutions. The liner system typically includes a composite geomembrane and clayey soil liner with a protective drain cover fill to maximize solution recovery and protect the underlying groundwater conditions. This paper discusses the types of pad liner systems currently used by the mining industry and the "good, bad, and ugly" lessons learned in engineering practice over the last 10 years in the design and construction of heap leach pads.

Jan 1, 1999

By Richard J. Leary

At the 1976 Annual Meeting of AIDE, Alan Merson reminded his audience that economic' success comes to those who understand things as they are, rather than as they have been or what ideology says they should be (1). He went on to say that, measured by this standard, the mining industry is in trouble. The mining firms had recognized long ago the importance of effective lobbying in Washington and the state capitals. But, he pointed out, those methods are nearly worthless anymore in coping with many land use problems because the critical decisions are likely to be made at the local level. There the tactics are far different as are the relations of the decisionmakers to the parties before then. Furthermore, in his estimation the trend is to leave land use regulation largely to the local level of government. All who are concerned for access to land for mineral development will be benefited by reading Professor Merson's paper lie is speaking effectively about the context of decisionmaking for specific cases, the shape of things in the here and now. There is, however, a longer-tern set of considerations that if pursued will be likely to foster the creation of public support for mining developments. At that sane meeting I spoke on two foundations of the long-term relationships: namely, the growth in requirements for minerals implied by projections of increasing consumption; and a rationale for fostering mineral exploration and development. I mentioned in passing the social decisionmaking process for public uses of land (2). This paper is intended as a complement. The growth of requirements for Minerals and the rationale for development based on the Entropy Law will be only mentioned. The main concern will be on the process of social decisionmaking in the context of access to land for mineral development.

Jan 1, 1976

The strength of anchorage of various types of roof bolts in permafrost depends on the types of rock in which they are installed. Variation in the mine thermal regime results in weakening of the roof and walls, and at times total loss of ice cement bonds takes place in the surrounding rockmass. In mines with positive ventilation air temperature, the wedge or expansion types of bolts may become weakened due to the transfer of heat into the anchorage through the metal rod and subsequent thawing of rocks. Effective operation and evaluation of roof bolt systems for mine workings in permafrost require predictions of the dynamics of wall thawing by warm ventilation air. This paper presents an analysis of the temperature distribution in the frozen host ground surrounding roof bolts, the area of interest being the vicinity of the anchors for point anchored bolt and the entire length for split set bolt

Jan 1, 1994

By M. J. Zdunczyk

Located approximately 50 miles northeast of Knoxville, Tennessee, Short Mountain Silica mines the Clinch Formation, an orthoquarzite, for silica sand. In 1980, a Knoxville resident and area contractor visualized mining Short Mountain for silica sand. Because APG Industries, the main market for the glass sand product, was only 48 kilometers from the site, many silica sand companies became interested in the property. In 1986, J.D. Nicewonder began to develop the site, and in May of 1988, APG Industries received the first sand shipment.

Jan 1, 1992

By Robert Stefanko

The importance of underground stress instrumentation cannot be minimized. It was Lord Kelvin who said that unless you can assign a number to a quantity,, you know very little about it. Most engineers will agree although this kind of statement is resented by our friends in non-technical fields. Mining is undergoing a revolution from art to science. But how can mining methods be optimized if there is no way of measuring the effectiveness of a given mining method? Do we know how effective a' support is unless we can determine its reaction to the mine structure? How do we assess the need for modifications to existing systems and supports, and how do we measure the effectiveness of such changes? Cut and try techniques are too wasteful of time and energy, and rarely provide solutions to a given problem. The purpose of underground stress instrumentation is to provide answers to some of the above questions -- answers that cannot be obtained otherwise This does not mean that laboratory studies are not valuable -on the contrary. Laboratory and underground studies supplement one another. Rock mechanics had its conception with the study of stresses in homogeneous, isotropic, and elastic models subjected to various force systems. These analyses were valuable inasmuch as they pinpointed possible sources of trouble due to stress concentrations. If the results observed underground did not always agree with the experimental analysis, it was not an indictment of the latter. More probably, the discrepancy could be attributed to the lack of similitude between model and prototype. The more nearly one can simulate underground conditions in a model, the more apt one is to produce results which correlate well-with underground observations. It is impossible to completely simulate underground conditions because all of the significant design parameters have not been recognized and evaluated. What better way can one evaluate these parameters than by underground stress instrumentation?

Jan 1, 1963

By Rodolfo V. de la Cruz

Abstract. The Hoskold mineral valuation method was critically examined. The original derivation was presented and found to contain a number cf erroneous assumptions as follows: the sinking fund must be available for reinvestment in another property; the series of reinvestment of the sinking fund results in a perpetual annuity to the investor, and; evaluation of the present value of the net cash flows at the speculative rate of interest. The proper procedure of deriving the Hoskhold mineral valuation formula was discussed and illustrated with a cumulative cash position diagram, a useful tool in economic evaluation and investment decision methods.

Jan 1, 1980

By Yuting Xue, Khaled Mohamed

The failure of coal ribs is a major hazard in underground coal mines. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have been working on the development of an engineering-based rib control method. A user-friendly standalone application, called Design of Rib Support (DORS), is being developed to ease the calculations of rib support. DORS can estimate the Primary Rib Support Density (PRSD, ton/ft2) for development loading. However, it still needs to take account of another key factor, bolt length, in rib support design. The bolt length can be estimated from the rib fracture depth, and this study focuses on the coal rib fracture depth analysis with numerical modeling and artificial neural network. A total of 331 FLAC3D simulations with different mining scenarios and rib conditions were conducted for this study. Machine learning was then used to predict coal rib fracture depth under different conditions. Based on the numerical simulations, the parameters for mining scenarios and rib conditions were collected as features for machine learning, and coal rib fracture depths were collected as the target to predict. Good data correlation (r-square) was obtained with the use of an artificial neural network. The

By R. H. King

The Deserado Mine of Western Fuels- Utah Inc. installed a micro-computer based mine wide monitoring and control system for mine environment, beltway fire protection, belt operating parameters, and equipment power utilization. The Colorado School of Mines was funded by the U.S. Bureau of Mines to document, evaluate, and report on the system design, procurement, installation, tests, and operation. This paper results from that project. The paper compares planned activities such as installation and start up, procurement contract specifications and system layout with actual performance to develop recommendations for future installations by mine operators.

Jan 1, 1987

By Gerald P. Kelton

Over the past quarter of a century, the success of the hydrocyclone as a classifier in closed circuit grinding installations has permitted the introduction of the cyclone into virtually all fields of wet industrial processing. Research and experience gained in these applications have established the optimum cyclone sizes and designs necessary to provide the required performance. Although cyclones are used in widely diverse liquid-solid applications, their use for ultrafine separation clearly demonstrates the importance of a familiarity with previous case studies. Krebs Engineers is firmly dedicated to serving the process industry and has acquired the unsurpassed knowledge and experience to handle all types of separations and classification problems. Cyclones have been used for a number of applications to make what might be considered fine separations. A typical example is in an iron ore grinding circuit where a 381 mm diameter cyclone will classify an overflow product to 85% -44 micron. There is no question that this is a fine separation, but still finer separations are possible, and these are known as ultrafine separations.

Jan 1, 1983

By Marcel Laflamme, Sebastián Ibarra‑Gutiérrez

Improvement on controlling the stope limits has enabled the assessment of technical performance in several underground mining operations. Technical performance, integrated to stope geotechnical and geomorphological parameters, constitutes the basis which guides mining engineers in the Mineral Reserves Estimation process. Moreover, there are established definitions to report this information in Canada, incorporated in NI 43–101, which stipulates that “A Mineral Reserve includes diluting materials and allowances for losses that may occur when the material is mined” [1]. However, some loopholes have been identified regarding practical standards followed to specify the way to include and report ore losses when the lost material was blasted and must be left behind unrecovered inside the stope. In fact, general efforts to estimate and quantify the negative effects of operational ore losses only consider under-break ore loss. However, mining engineers frequently confront situations requesting the anticipated closure of a stope. Therefore, reconciliation process should reflect the amount of unrecovered Mineral Reserve. This work presents a discussion of possible practices to integrate adequately operational ore losses consisting of blasted but not recovered material and focuses on how different approaches regarding the material constitution could severely affect the stope technical performance interpretation.

Aug 9, 2021

By M. A. Alan

The Bellavista Gold Deposit lies 75 Kms north west of San Jose, the capital of Costa Rica, Central America and 3 Kms north east of Miramar, in the Province of Puntarenas. The total road distance from San Jose to the deposit is 120 Kms all paved road except for a 2.5 Km graded, gravel road on the property (Figure 1). Infrastructure services in the Miramar-Puntarenas area are well developed with electrical power distribution, a modern port facility and community services being available. The deposit lies on the south west flank of the Tilaran Mountain Range between an elevation of 550 and 800 meters above sea level. The local topography is steep, originally covered with pre-montaine, tropical wet forest vegetation which has been largely destroyed due to clearing for cattle grazing. The annual rainfall is approximately 2,950 mms, 90% of which occurs between May and October.

Jan 1, 1992

By Clyde N. Garman

Historically, Vanadium and Uranium have been precipitated together in carbonate sill circuits. A separation of the salts of the two metals was then made on the basis of the fact that the reduced, salts of vanadium are more solo to and those of uranium lose soluble than the respective salts of higher valence. In practice this was carried out by fusing the precipitated combined concentrate with salt, sodium carbonate and sodium hydroxide with oil soaked sawdust mixed into the charge as the reducing agent. Generally the fusion was carried out batch wise and the resulting slag or glass leached in water. A good, fusion and three or four decantation washes resulted in almost complete recovery of the vanadium in the liquid phase and a very high recovery of the uranium as a dense black U02 solid.

Jan 1, 1962

By R. C. Runvick

Gypsum resources are significant in the midwestern United States, with specific deposits varying in "place value" relative to the major markets served. Underground and surface mining operations produce gypsum from sedimentary rocks ranging in age from Silurian through. Jurassic. Although reserves tend to be limited at individual operating properties, potential resources are vast and future development will hinge principally on market growth and changing economic conditions. Most critical of the variables affecting the industry in both the short and long term will be the availability, type and cost of energy and both processing and distribution.

Jan 1, 1980

By Edmundo Tulcanaza

Increasing exploration costs and the need to reduce the time-frame from exploration to production presently demand formalized procedures to assist exploration planning and reserve analysis. Exploration planning is basically required to select the most cost-effective drilling/sampling program, and to flag the needs for data of greater relevance and reliability. Reserve analysis is necessary to determine the sensitivity of grade-tonnage relations, and to clarify the economic implications of mining when alternative technical choices are to be considered.

Jan 1, 1982

By R. L. Teseneer

Pyrite samples from twenty-one locations in the North Carolina Slate Belt were analyzed for cobalt, gold, mercury, and nickel by atomic absorption spectrophotometry. The geographic distribution of relatively high values of certain trace elements in pyrite suggests that, in addition to gold, cobalt and nickel metallogenetic provinces are possible in the slate belt. Northwest trends of province boundaries may be genetically related to subsurface features rather than to surface geology. Within province boundaries gold and nickel exploration programs should be concentrated in areas containing intermediate to mafic tuffs, while cobalt may be more concentrated in argillites and phyllites.

Jan 1, 1979

By C. Milne, T. M. Dyhr, T. E. Wilson

As time progresses, new concerns regarding long-term post-mining effects are identified, increasing mine closure costs. Regulators responding to public interest must take a “worst case” view and require post-closure monitoring or remediation processes. Although closure costs depend on the size and type of operation, general cost categories are defined, and median values (per acre, or per unit of production) are identified. Closure cost categories, as well as amounts, have increased with time. Except for increased efficiency in earth-moving and water management (surface or subsurface), there are no apparent offsets to a steady rise in closure costs. When the historical trend of closure costs is considered, it is probable that additional cost categories will come into being. For mine operators, the challenge will be to anticipate them and devise cost-effective remedies.

Jan 1, 2003