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By Peter F. Howard

The lower Middle Cambrian phosphorite deposits of the Georgina Basin shown in Figure 1 were found in the period 1966-1968 by three companies, namely, International Minerals and Chemical Corporation, Continental Oil Corporation and Broken Hill South Limited. Of these deposits the significant ones are Duchess, Sherrin Creek, D Tree, Lady Annie, Lady Jane, and Wonarah which together aggregate several billion tons reserves of phosphate. Due to the economic factors of freight costs to the coast and softening of the world market price for rock phosphate, none of them is in production, nor is any in the development stage. This paper reviews the historical background to the discovery of these deposits and then deals principally with the discovery of non-outcropping phosphorites in the Barkly Tablelands of Northern Territory by the interpretation of gamma radiation logs of abandoned water bores.

Jan 1, 1971

By D. J. Tooker

For the next few minutes, I will be discussing a product and category that many people laughed at for years. The product is cat box filiers or commonly referred to by the brand name KITTY LITTER. This product was introduced in 1947 by Ed Lowe using the name KITTY LITTER. From 1947 to 1964 the product was sold mainly through pet shops. Starting in 1964, the grocery trade began to carry cat litters. From that point, the cate gory began a solid growth trend. Particularly in the '7O's, cat litter has experienced the same kind of explosive growth that has characterized the entire pet market. For example, in the twelve months ending 9/21/79, cat litter unit volume grew by 15% versus the previous twelve months. The basis for this explosive growth is easy to comprehend. The cat population itself is rapidly expanding, reflecting the changing life- styles of Americans. As famiiies grow smaller, there is room for a pet. As apartment and con dominim living shrinks living space, a cat fills the human need for animal companionship more efficiently. Table I illustrates current cat litter market factors and projects major trends into the future to conclude that the cat litter market will equal $205MM in 1985. With this dynamic growth defined, it was imperative that a company such as Lowe's that was totally devoted to the commodity-priced products, evaluate the opportunities for added- value product differentiation. This process was started approximately four years ago with a search for new cat litter products and other new product opportunities.

Jan 1, 1980

Coal that meets customer specifications is often stored in silos before being loaded into cars. It is often found that coal in a particular car does not meet customer specifications due to the mixing of coal inside the silo. Some new contracts require meeting specifications on a per car basis. Silo flow models are used to predict quality in such cases. However, coming up with an accurate silo flow model for each case is very difficult and time consuming. This paper examines the viability of using an online analyzer at the loading end of the silo in conjunction with a feedback circuit, to optimize the quality of the coal being loaded into trains, so that each car meets quality specifications.

Jan 1, 2000

By L. B. Phelps

The nation is confronted with thousands of acres of abandoned coal lands. In Pennsylvania alone, these lands have been estimated to cost $15 billion to reclaim (Pennsylvania Bulletin, 1985). One way to deal with this problem is to provide a mechanism by which the active mining industry can undertake to remine certain of these abandoned mine areas. Remining is classified as reaffecting previously mined areas in order td extract the remaining coal reserves while improving the environmental quality of these lands through land restogation and abatement of pollutional discharges. However, there currently is a disincentive for operators to plan to extract reserves on these abandoned mine lands which have preexisting pollutional discharges. Therefore, they presently avoid them. This is because of the "potentially unlimited liability of post- mining treatment for any discharges that would remain after mining? (Pennsylvania Bulletin, 1985).

Jan 1, 1987

By D. Rucker

Flow models are used to predict the extraction efficiency of metals in rock piles. These models typically use hydraulic parameters obtained through column studies, which assume that the material in the column wholly represents the entire pile and the parameters can be upscaled several orders of magnitude for model evaluation. This assumption fails for parameters that are spatially variable or scale dependent. To overcome these issues, measurements made directly on the heap at the appropriate model scale can be made with the electrical resistivity method. The method aims to map the variations in the electrical resistivity, which can be associated with moisture content, degree of fines, metal content, and leachate concentration. We present an example of calibrating the resistivity with borehole measurements of moisture using geostatistics to show how the resistivity method can be used to obtain a spatial moisture distribution. It was shown that cokriging the resistivity and moisture together gives a more reliable distribution.

Jan 1, 2010

Several years ago, North American mining companies began to realize they needed to expand their spheres to remain viable. This strategy has been successful, according to Robert W. Schafer. Today, companies from other continents have also recognized the need for an international view for long-term growth and viability, he said. Schafer is vice president for exploration with Kinross Gold. He was the program chairman and moderator of the keynote session at the 1997 SME annual meeting, held in Denver, CO, Feb. 23-27. The theme of the meeting was "Minerals - Serving the Global Community." A record attendance of more than 6,000 people participated in the meeting, which featured 415 exhibitors occupying 582 booths. The title of the keynote session was "Corporate Perspectives on a Global Minerals Industry." Each of the three keynote speakers discussed a different perspective of a global minerals industry.

Jan 1, 1997

By K. Fountain

In Novemeber of last year I visited a mica mine in Hunan Province, China. For nine months , we had been trying to sell Chinese mica to a customer in Belgium. Talking to the customer was like negotitating with a stone wall. The buyer refused to communicate any -thing other than his steadfast refusal to consider Chinese mica. He would not advise us what he wanted, what specifications or grades. He would give no indication if our price at market, or reasonable, or totally out to lunch. He would not even accept samples. It took no genius to guess that the mica buyer had at some time in the past bought a shipment of Chinese mica and had received a disaster. I invited the mica mine in Hunan in order to see for myself what could be done - without massive investment in equipment and instruments - to upgrade the quality of the mica for export. We had seen this type of customer reaction before. One disgruntled customer who had pur¬chased pigment grade barites direct from China ranted and raved about unreliable and inconsistent quality. It did no good to explain to him that China is a big country, with hundreds of mines scattered throughout many areas, each producing a different product. Our further explanation that Chinese export organizations also varied in degree and efficiency of customer service fell on deaf ears. Samples had no effect on his perception. Eventually we showed him photoraphs of two mountains of pigment grade barites. One lot was our sales of pigment barites to a major European minerals processor. Our Chinese barites stood proudly white and beautiful next to a hill of other material which now appeared at best mediocre and dull by comparison, and which the buyer had decided to reject after he received our Chinese barites. Finally the customer was sufficiently impressed to look seriously at our guaranteed specification and the outturn analysis performed by our other customer.

Jan 1, 1987

By C. H. Bucknam

Principles of Green Chemistry provide useful guidance for sustainable mineral process development. Laboratory bench scale testing was carried out using pregnant cyanide leach solutions, and a number of commercially available mercury precipitation reagents were compared using jar testing to determine the most efficient and selective reagents for mercury precipitation. The most efficient reagent identified was sodium polymeric thiocarbonate (NaPTC).Coagulation experiments with fine diatomaceous earth resulted in a stable precipitate, with good settling properties. On line monitoring of the mercury in solution is recommended for process implementation to conserve reagent removing approximately 90-95% of the mercury with minimal silver and negligible gold losses.

Jan 1, 2004

By E. Cho

Illinois No. 6 coals of IBC 101 and IBC 112 were treated in solution with sodium hypochlorite to remove their sulfur contents, especially organic sulfur. The lab experiments were conducted in two steps of leaching at room temperature and hydrolysis at 90oC. The removal of organic sulfur from IBC 101 was by 37.8% while that from IBC 112 was only 13.7% under their respective optimum conditions. This large difference in organic sulfur removal is considered to be due to difference in concentration of surface total acid group, 3.14 vs. 0.88 mmol/g of coal.

Jan 1, 2007

By Vincent T. Ricca

Acid mine drainage is a serious water pollution problem, for its contaminants will eventually effect the quality of the receiving streams. According to the Appalachian Regional Commission (1969)1, 10, 500 miles of streams have been polluted by mine drainage, and 70 percent of this acid pollution is accounted for by underground mines. Due to the severe damage to aquatic life, to recreational and industrial use, and to domestic water supply, more stringent mining and anti-pollution laws have been legislated and coal mine operators are required to treat the mine water discharges to meet the minimum standards. For years now, abatement and treatment methods have been extensively studied. Progress reports presented in the Fourth Symposium on Coal Mine Drainage Research, 1972 1 suggest that a thorough investigation and understanding of the basin discharge is necessary in order to cope with the mine drainage problem. The extent of mine water discharge contamination can be considered as a function of the basin streamflow and acid generation load.' A conservative treatment cost estimation these days is $0.40 per 1, 000 gallons for water with 100 ppm iron, 500 ppm acidity. These figures need not include collection and pumping costs nor the cost of dispersing of chemical waste by-products. To achieve optimal abatement and treatment of mine drainage, predictions of the quantity and quality of mine water discharges are needed. Basin discharge is a continuous process and it can be considered as a. macro-system. This system can be subdivided into micro-systems to describe the various mine discharge .types in the basin. The mining activities could produce acid water discharges from deep mines, stripmines, or associated gob piles. A total study entitled ?Resource Allocation to Optimize Mining Pollution Abatement Programs?* will consider all of these sources. However, this paper will discuss only one micro-system, the drift (deep) mine type. We will look at a single mine and its watershed. The total research project considers a multiple mining complex in an extensive stream basin.

Jan 1, 1973

"Metallurgical process development in greenfield projects must define the comminution flowsheet and establish the equipment sizes that are required to deliver the project design criteria. These are critical steps that heavily influence the financial performance of the project, requiring a detailed understanding of the ore properties of the project resources and the best practice methods to size comminution machines. This paper reviews current practices for determining the ore characteristics relevant to comminution circuit design. Particular attention is given to the design of sampling and testing programs, and the methods commonly applied to size crushers and mills for conventional size reduction applications in mineral processing. IntroductionMetallurgical process development in greenfield projects requires the selection of a comminution flow sheet and must establish the equipment sizes required to deliver the project design criteria. This necessitates a detailed understanding of the ore properties that define the project resource. For brownfield projects the same objectives may apply for plant expansions, or the project objective may be simply to define the capacity and operating cost of an existing facility for a new ore source. The process development phase in either instance will typically comprise the following key activities:• Geometallurgical classification and sampling of the ore deposit or deposits.• Determination of comminution energy requirements.• Benchmarking similar projects.• Identification of flow sheet options.• Equipment selection and sizing.This paper is concerned specifically with process development testing and will as such focus on the first two activities on the list: sampling and testing of the deposit. The discussion will focus on testwork programs to support the design of comminution circuits commonly in use in mineral processing today, specifically crusher, tumbling mill and stirred mill technologies.It is important that any testwork program is designed giving consideration to the types of flow sheets that are viable for the project, and the data that will need to be generated to support the final equipment sizing. Designing a testwork program to only provide information about one particular type of flow sheet will not allow sufficient information to be generated for a rigorous trade-off analysis of options, and may therefore preclude financial optimization of the project. Testing programs should be designed to collect sufficient data to ensure that any backtracking at a later stage to fill in missing information is minimal."

Jan 1, 2016

By Donald E. Stump

Subsidence from underground coal mining alters surface water discharge and availability. The magnitude and areal extent of these impacts are dependent on many factors, including the amount of subsidence, topography, geology, climate, surface water - ground water interactions, and fractures in the overburden. These alterations may have positive and/or negative impacts. One of the most significant surface water impacts occurred in July 1957 near West Pittston, Pennsylvania. Subsidence in the Knox Mine under the Coxton Yards of the Lehigh Valley Railroad allowed pan of the discharge in the Susquehanna River to flow into the mine and create a crater 200 feet in diameter and 300 feet deep. Fourteen railroad gondola cars fell into the hole which was eventually filled with rock, sand, and gravel. Other surface water impacts from subsidence may include the loss of water to the ground water system, the gaining of water from the ground water system, the creation of flooded subsidence troughs, the increasing of impoundment storage capacity, the relocation of water sources (springs), and the alteration of surface drainage patterns.

Jan 1, 1986

By L. Gertsch, R. Gertsch

Mechanical mining is steadily gaining usage in the mining industry. A variety of machines currently finds employment: tunnel boring machines, roadheaders, continuous miners, surface miners, and augers. These machines have advantages compared to drill and blast mining methods, including increased safety, lower cost, uniform muck size, and accurately sized openings. A century of experience with mechanical methods has already paid dividends to the coal industry. Current trends guarantee eventual development of true general-purpose hardrock mechanical mining machines. Mechanical miners will become integrated mining systems and will determine the design of mines, when several significant challenges have been met.

Jan 1, 2001

By E. Iasillo, R. R. Carneiro

Independent of the method chosen to forecast production, an accurate method to project metal extraction is needed in order to accommodate leach cycles that exceed leach data on hand and thus be able to accurately forecast production. Metal extraction data must be developed for each ore type identified in the deposit in order to apply the correct rate of leaching when a specific ore is being treated. Curve fitting is used to model the rate of disengagement of metal into the pregnant solution. This paper provides a description of a curve fitting algorithm developed by Mr. John T. Bartlett, inventor of the METSIM™ process simulation program. A methodology is provided by which the metallurgical data developed is evaluated to determine if accurate projections may be made from the data. A criteria has been developed to help determine when a column experiment may be terminated.

Jan 1, 2001

By A. Bhattacherjee

Industries in general and the mining industry in particular have become more safe than ever before. However, there is a need to increase the search for the causes of mining work-related injuries and to contribute to their reduction through job design, work procedures, and worker training. Mine accident and hazard control has to be practiced in a manner which is consistent with the overall objectives of the mine management, among which are the optimum allocation and effective utilization of the resources. The purposes of this paper are to (i) review the role risk analysis in safety management with references from mining and other industries; (ii) discuss the risk measures appropriate for injury analysis; (iii) present a set of analytical tools to injury experience data in under-ground coal mines; (i v) apply these tools on case study example; (v) discuss the results of the case study; and (vi) amplify the application limitations and the future research needs.

Jan 1, 1991

By J. R. Kunkel, V. Lishnevsky

At mine sites, the operational and required storage volumes of solution and water storage ponds and reservoirs are usually calculated based upon a water-balance approach. Many climatological variables including precipitation, air temperature, solar radiation, pan evaporation and relative humidity along with operating parameters, are used in the water-balance model. The water-balance model often seeks to find a “critical period” of wet or dry climatological sequences which result in a “maximum” pond storage volume or water demand. The problem with this approach is that the designer usually does not know when the project will come on line in relation to the historical record. To avoid this pitfall, we use a more robust approach. In the more robust method, the water-balance calculations begin in each year of the historic climatological record. This method results in the same number of water-balance runs (or realizations) as the number of years of climatological record. Results of this type of analysis guarantee that the critical period or maximum required pond volume will be found if it is assumed that the historical climatological record repeats itself or if a synthetic time series is used. In addition, this method permits calculation of the likelihood (probability) that a given pond volume will be equaled or exceeded in any given month of the operational life of the facility. In this paper, the results of the sizing of a heap leach pad solution pond are presented along with the probabilities of a given solution pond size being equaled or exceeded based on the robust water-balance approach.

Jan 1, 2002

By Donald R. Simon

Money... not many subjects are as personal or as emotional. Hessiod said it well in 700 B.C. "Money is life to us wretched mortals". Are you getting paid enough? Does your company reward its top people? Does coal or copper pay more? Production or engineering? How is the synfuels industry going to influence mining salaries? Do high salaries attract and retain the best people? Do modern compensation systems ensure fairness or destroy entrepreneurial spirit? With our tax system and high standard of living why are we so salary conscious? Salary is not only important for what it can purchase but it is also a yardstick, measuring how well we are doing. We all need money to pay the bills and maintain our standard-of-living, but once we reach a certain point the psychological ramifications become more important than the purely practical side. Even necessary payments like the mortgage and the car are a function of our egos. Are our choices of cars and homes based on simple transportation and shelter?

Jan 1, 1980

By T. Panhorst

Evaluation of through-deck blasthole sample reliability at the Lone Tree gold mine revealed a non-systematic bias in the sampling system. Ore is primarily hosted within the Powerline fault zone. Clay gouge, present in the fault zone and typically enriched in gold content, forms agglomerates during blasthole drilling leading to a segregation error during sampling. Replicated samples split from blasthole cuttings piles show through-deck samples to be either significantly enriched or depleted by 1.5 standard deviations or more from the mean gold content of their respective cuttings pile quality of through-deck samples correlates strongly with quantity of clay present.

Jan 1, 1999

By Bodo Peinemann

For more than 35 years Lurgi has been providing its fluid bed roasters on a world­wide basis. The current total annual capaci­ty of the 250 Lurgi roasters approaches 26 million mt of sulphide minerals, including gold-bearing flotation pyrite concentrates. While the stationary fluid bed has been uti­lized for roasting exclusively, Lurgi has now commercially introduced its Circulating Fluid Bed (CFB) technology for gold roasting in a successful effort to maximize gold re­covery.

Jan 1, 1990

By R. A. Jankowsi, S. K. Ruggieri

Airborne respirable dust levels on longwalls can be reduced if operators approach the dust control problem in a logical and fundamental manner. This can be accomplished through the proper application and continued use of effective dust control techniques. The Bureau of Mines is currently assessing the effectiveness of longwall dust control techniques in use today to provide mine operators with guidelines for selecting the most appropriate control technology. This paper presents a fundamental approach to the problem of shearer dust control. Three dust control techniques to be discussed are: deep cutting/increased pick penetration for reducing the amount of respirable dust generated; drum water sprays/improved water supply system to suppress the amount of airborne respirable dust; and improved external water spray system, the "shearer-clearer," to push the dust close to the face. The techniques have been evaluated in field trials and have been shown to be both practical and effective in applications to control shearer generated dust.

Jan 6, 1985