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By A. F. Klebanov, K. N. Trubetskoy, M. Yu Khoudine, V. L. Postnikov

The information system of monitoring of mine receive layouts is being created In the "ROSUGOL" Company for the prompt analysis of the state-of-the-art of mining operations at under- ground and open cast mines of the Company, rapid and effective decision-making and elaboration of recommendations on the basic directions of enterprise development. The data bank storing the digital mapping and attributive information describing the actual background of mining operations at the enterprises of the Company is the core of the system. The Oracle database management system and the ARC1 INFO geographic information system have been chosen as basic software packages for the Project realisation. The updating of the information will be performed on a regular basis via the transmission of actual digital data on under- ground and open cast mine layouts In ARCIINFO conversion to the central office of the "ROSUGOL" in Moscow. Centralised storage of digital mapping and attributive data, database administration and navigation is effected with the Oracle software package. Access to the data in the operation mode with an interactive display map will be effected with the use of the local computer net of the "ROSUGOL."

Jan 1, 1996

Computer applications in mine 'production' planning and control are concerned with the here and now. In production planning and control we are dealing with tactics as opposed to strategy. Our objective is to make the best of the situation in the short term, i.e., in a relatively fixed environment with relatively fixed plant, equipment, and labor. Environmental factors include not only the geology of the deposit but also market factors (such as price) and governmental constraints and regulations. Mine production planning systems are applied at the interface between concept and execution. Mine production control systems are applied at the interface between execution and revised operating practices or a revised concept. Fig. 1 shows the information flow that takes place regardless of whether the planning and control systems are manual or automatic. The feedback that results depends on the feedback mechanism that has been established, and this feedback can be enhanced by careful systems analysis and design. Chronologically, production planning and control activities support the last in the series of line functions that are ordinarily performed by mining companies. The first of these is exploration, the second is evaluation and development, and the third and final function is production.

Jan 1, 1979

By Mahesh C. Jha, Frank J. Smit

Column flotation and selective agglomeration are promising advanced physical cleaning processes that can be developed for preparing premium quality coal-water slurry fuel from coal fines. Such a fuel could either replace oil or natural gas in certain industrial and utility boilers or else could be burned in advanced combustors currently under development. These applications require coal cleaned to sulfur and ash contents below 258 g/GJ and 430 - 860 g/GJ (0.6 lb/million Btu and 1 - 2 lb/million Btu), respectively, to meet clean air emission requirements. A highly loaded slurry must be produced in order to avoid derating the boilers, and the total cost of the fuel must be below $2.37/GJ ($2.50/million Btu) in order to penetrate the market by the turn of the century. Achieving these technical and economic goals depend critically on the selection of suitable feed coals. This paper describes the identification and evaluation of 18 coals and final selection of six coals from different regions of the United States as potential feedstock for preparation of premium fuel. The work is being performed under a cost-shared DOE project.

Jan 1, 1995

By Roderick K. Davey

The objective is to develop a short-range mining plan which satisfies management and operating criteria and also "dovetails" with the long-range mining plan. In the past years, this objective was accomplished entirely by manual methods. Today, the computer is used to assist the engineer with this task. The results provided by these programs usually are incomplete and require further manual manipulation. The advantage of using the computer programs is that the program can be used to evaluate alternative plans on a first-cut basis minimizing the manual work. Subsequently, the most promising alternatives can be analyzed in more detail, commencing with the first-cut results. In this specific case history, one technique for using computer programs to assist with short-range mine planning will be discussed. Some of the basic operating and management criteria considered directly and indirectly are as follows: (1) operating criteria which include minimum and maximum shovel cut size, equipment performance, haulage roads, requirements for blending, and plant capacities; and (2) management criteria which consist of production requirements, cash flow requirements, return on investment, market demands, and availability of capital.

Jan 1, 1979

By D. R. Spears, D. A. Stanley

The US Bureau of Mines investigated the fundamental aspects of shear-flocculation using a rapid, in-situ particle size analyzer. Silica was stirred in the presence of an aliphatic amine to determine the effects of collector coverage, stirring speed and solids concentration on the kinetics of shear-flocculation. The results showed that shear flocculation is a two-stage process. In the first stage, which occurs during the first 1-2 min. of the reaction, the mean particle size increases rapidly, and in the second stage, an equilibrium is set up between the rates of floc growth and floc decay. Collector dosage affected the position of the equilibrium by altering the number of surface sites for particle-particle attachment. A minimum stirring speed was necessary for shear flocculation, which was dependent on solids concentration and collector dosage. This stirring speed was the minimum necessary for particles to overcome the electrostatic energy barrier, and that results in keeping the conditioned particles dispersed. Larger particles flocculated more rapidly. At very high stirring speeds, large flocs became unstable, resulting in a narrowed particle size distribution in the slurry.

Jan 1, 1995

By Wang Yingmin, Xu Zhuyun

There are 3 steps in the process of forming a mine ventilation system, (1) selecting a reasonable ventilation pattern (included pit shaft arrangement); (2) optimizing of the ventilation network and (3) computing and outputting the flow splitting results of the network with the optimal ventilating equipments selected. In the past, the first step was relied on artificial decision-making. In order to design a common ventilation system, some ventilation experts were needed to participate or do some examinations. Even so, the design made was reasonable only for those experts. If there is a mistake in the first step, then even the followed 2 steps are best done, the losses are very difficult to retrieve. So that, the first step is very important. The development of expert systems provided an efficient means and tool for all engineering fields. This paper presents an expert system of selecting mine ventilation pattern and pit shaft arrangement. After testing many times, it is shown that the system can perform the first step of designing a mine ventilation system, and can help the experts doing their study works more efficiently.

Jan 1, 1991

By G. E. S. Valadão

This paper is concerned with studying the dewatering behavior of three samples of iron ore products. The objective is to improve the industrial filtration performance by taking into account the laboratory results. Mineral samples came from the Iron Ore Quadrangle in the state of Minas Gerais, Brazil. These samples represent products from the industrial processing of hematitic ores. The samples have almost the same chemical and mineralogical compositions, but they have different size distributions and different specific surface areas. The filtration tests were performed using a modified Büchner funnel apparatus. The results indicate that size distribution and specific surface area have significant influences on dewatering behavior. For Sample 1, the addition of flocculant and/or surfactant was not essential to improving filtration performance. For Sample 3, the cake porosity and the cake thickness were influenced by the addition of the flocculant. On the other hand, the simultaneous addition of flocculant/surfactant decreased the cake formation time and reduced the cake moisture. For Samples 2 and 3, it was also observed that the industrial operation could be improved by taking into account these laboratory results. Key words: Dewatering, Iron ore, Hematite, Filtration, Flocculation, Surfactant

Jan 1, 2003

By Peter J. Tarkoy

The art of predicting rock excavating machine performance has become increasingly detailed and refined. Researchers using laboratory experiments and machine manufacturers using field observations have identified and defined mechanisms of failure, rock and tool interaction, and relevant design principles affecting them. Concurrently, practitioners have developed index tests which reflect rock properties relevant to machine performance. Empirical relationships between index properties and machine performance (penetration rate, cutter consumption, and machine utilization) have been established from past experience and are currently used throughout the industry. Contractors have used such relationships for estimating throughout the world. The detail in which geological, geotechnical, test, and project data, empirical relationships, and construction experience are utilized, is limited by time constraints imposed by the bidding period. To fully utilize all available data, methods of analysis, and construction experience, a simple computer program was developed for a microcomputer costing less than $7500. As a result, 1. machine performance predictions are detailed & reliable, 2. construction alternatives may be examined, 3. anticipated conditions & performance are graphically, documented & easily comparable to those encountered, and 4. results include a listing of assumptions & results of performance analyses & a graphic performance summary.

Jan 1, 1979

By F. Chavan

1. Introduction The new Cleuson-Dixence development project in the Valais region of the Swiss Alps, involves the construction of a new link between the Grande-Dixence dam (still world recordholder with a height of 300 m) and a power house on the banks of the Rhone consisting of approximately 20 km tunnels and shafts, and involving a fall of about 1900 m. This 1200 MW project will replace an existing 900 MW structure built in the 1960s, no longer considered efficient. The new project comprises a head race drift about 15.8 km long, a surge tank, an inclined cascade shaft 4,2 km long, and an underground power station. The work for lots C and D (head race drift from Tortin to Tracouet, surge tank, six adits ans the complete inclined shaft) was awarded to our group (Prader, Locher, SELL, Losinger, Evéquoz, Dénériaz, Imboden and Bouygues). The geological conditions are: Lower part of the shaft (300 m) : sedimentary - sandstone and soft tertiary sandstone. Middle and upper part (2600 m) : metamorphic - upper and lower carboniferous, interrupted by triasic chipping. The horizontal section (7 km) consists of mica

Jan 1, 1995

By Marcel Haffen, Jean Janin

The purpose of grouting is to modify the permeability and strength characteristics of the subsoil in such a way that the planned structure can be efficiently constructed at a given location. This technique, which originally underwent considerable development in the field of dams construction is constantly evolving and it becomes more and more important in urban zones of intensive underground development for projects such as transport tunnels, stations, car parks, ect. Grouting becomes more and more indispensable whatever the natural characteristics of that subsoil ; such is the case particularly when the planned work runs through cohesionless granular soils, usually water-bearing such as alluvium, sands, disturbed ground, fill material, etc. The selection of the grouting method and the extent of treatment required at depends on two fundamental factors. 1º) nature and behaviour of subsoil to be treated. There is no need to stress the necessary of a good knowledge of geotechnical, hydrological and chemical characteristics of the ground to be treated. At the present time the specialists in these fields have available numerous methods of analysis, either laboratory or field tests, which enable to evolve a suitable treatment.

Jan 1, 1997

By Robert S. Saunders

Cast iron tubbing for two centuries was the only practical watertight shaft lining for deep waterbearing formations. However, since World War II composite welded steel and concrete lining has gained favor and today is often preferred. While tubbing may not be applicable in all cases, a good argument can still be made for this time-honored method. Watertight linings are complex structures designed to withstand both hydrostatic fluid pressure, non-uniform loading created by ground forces, and vertical bending caused by subsidence. Resulting stresses in the lining can be high. To date linings have been designed that withstand hydrostatic pressures as high as 1,500 psi. Watertight linings must be robust, constructed of the highest quality materials, and manufactured and installed with precision. Therefore, such linings are expensive. Today's ductile cast iron tubbing is greatly superior to gray iron formerly used for tubbing, and is stronger, and more resistant to corrosion than welded steel lining. Tubbing, unlike steel linings, can be installed in wet conditions and used to control water inflow and stabilize unconsolidated ground as the shaft is deepened. Steel lining requires absolutely dry conditions for welding, which often necessitates expensive ground freezing and a primary lining.

Jan 1, 1985

By Sean E. Armstrong, Deepak Malhotra

Gold extraction from refractory ores as a percentage of total gold production is increasing. The processing technology options for treating difficult-to-process refractory ores are also increasing. The best processing option is dependent on many factors including feed grade and the cause for ore refractoriness. The causes for ore refractoriness are many foldCpreg-rob­bing, encapsulation in pyrite, arsenopyrite or silica, presence of cyanocides, presence of cyanide-insoluble gold compounds, etc.1. The first step in the process development of a refractory gold deposit is to determine the cause for ore refractoriness. The traditional approach of undertaking detailed mineralogical examination of ore types, major and minor mineral constituents and their association does not necessarily provide the metallur­gist all the information needed for characterization of gold-bear­ing ores. For process development programs it is desirable to complement traditional mineralogical methods with diagnostic leach testing, which attempts to quantify the deportation of gold in various mineral matrices. This paper briefly reviews the diagnostic leaching proce­dures and its applications for a wide range of gold-bearing refractory ores, both primary and by-product.

Jan 1, 1996

By Richard H. Johnson

The Castle Mountain Mine (CMM) is located in the eastern por­tion of San Bernardino County, Southern California, 70 miles south of Las Vegas. The CMM is a joint venture between Viceroy Gold Corp. (75% and operator) and MK Gold (25%). The CMM initially started gold production with an 8,000 tpd cyanide heap leach operation in February, 1992 when the first ore was crushed and delivered to the leach pads. Even during construction and commissioning, design work was under way to engineer and construct a 1,200 tpd Mill circuit to process the higher grade fraction of the ore through use of pulp agglomera­tion. The need for a grinding circuit became evident with the quantity of high grade material delineated during drilling and the amount of visible gold that the geologists were finding in the drill core and R.C. cuttings. Viceroy did not want to stack the higher grade ore on the heap, and it was clear that permitting a tailings pond would, at best, be a long drawn-out affair. An alternative to a tailings facility had to be found.

Jan 1, 1996

By Hans von Michaelis

The revolution in development of new technology and practices in the gold mining and metallurgy industry continues unabated despite the ups and downs in the gold price. Some of the new cutting edge technologies are listed in Table 1 overleaf. There is room to discuss just a few of these here, but many more are identified and described in RANDOL (1992). Cutting edge advancements in gold recuperation, can be sorted into three categories. The first category includes fundamental advances that offer major improvement with significant economic benefits. Second would include evolutionary developments that offer smaller, but nonetheless commercially valuable improvements. Finally there are those "advances" that are interesting but of trivial or question­able economic benefit to industry. It is essential to adopt a "systems approach" philosophy towards developing and applying new technology. Practical innovation often comes about as a result of having to solve a problem. Innovation for innovation sake is an ego trip. Environmental management has become an important part of the system and the environmental implications of new processes and practices in the mine and mill have to be carefully considered for potential benefits and/or liabilities.

Jan 1, 1993

By R. M. Ocampo-Franco

The line seven, as part of the development of the Subway Master Plan in Mexico City, will tunnel under different subsoil conditions of clay with high water content and low shear resistance located between 8 and 12m beneath the surface. Boulders in silty sand and gravel to a 40m depth underlay this stratum. Economics, scheduled time of construction, and the obligated interconnection with existing lines one and two determined the construction of the tunnels to have an overburden of 1.0 to 2.2 times the diameter. In the north part of line seven there is a track of 251m length that was decided to attack with an open shield of 9.14m of diameter due to the characteristics of the sub-soil, minimum section needed as well as a minimal overburden, of 10.41m. The paper explains the construction procedure from the excavation stage to the reinforcement of the final lining obligated for the ground subsidence as a result of volumetric changes of a stratum of 4m thick of clay overlying the crown of the shield. Manuscript not received in time for publication.

Jan 1, 1983

By Edward J. Miller

Explosions and fires are without a doubt two of the most feared occurrences in modern underground mines. When they result in loss of life or substantial property damage, they usually gain world-wide media attention and have, on occasion, provided the impetus for legislative action. The very involvement of the Federal Government in mining was the result of a series of explosions which resulted in the loss of hundreds of lives. Fortunately, explosions of this magnitude are rare. Fires and explosions of lesser consequence are, however, more common and their severity may be more a matter of luck than anything else. The publicity which these events receive is usually restricted to the area immediately surrounding the mine and a1 though MSHA and sometimes the state prepare reports of their investigations, the general mining community is quite often aware of the circumstances surrounding these occurrences. This paper will discuss some of these "lesser" explosions which have occurred recently. These explosions have sometimes occurred in sealed or otherwise inaccessible areas of the mine involved, where conventional ignition sources such as electrical power were not present.

Jan 1, 1987

By J. R. Hindman

The vermiculite review arrived too late for the June issue. In 1992, production of commercial vermiculite in the United States increased 1 % to 170 kt (187,000 st), according to the US Bureau of Mines. The estimated value of vermiculite concentrate was $13.6 million, yielding an average value of $80/t ($72.50/st). Vermiculite is used in several physical forms. Use of the thermally exfoliated product include light weight aggregates, horticultural growth media, thermal insulation applications and absorbents for spill control and liquid waste containment. The untreated commercial concentrates are used as intumescent fillers in plaster board, gaskets and paints. Several chemically modified vermiculite products include clay-sized dispersions and granules for treating flue gas. South Africa was the only major foreign source of vermiculite used in the United States. It exported about 40 kt (44,000 st) to the United States last year. In 1992, Palabora Mining Co. began processing vermiculite in a new beneficiation mill at Phalabowra. It produced about 164 kt (181,000 st). Minor sources of foreign vermiculite concentrates consumed in the United States included about 140 kt (154,000 st) from China. Brazil also exports some concentrate to the United States.

Jan 1, 1993

By James T. Furey, Laurence D. Hartzog, Graham A. Karklin

A pilot plant study was conducted to evaluate the performance of column flotation in the recovery of gold from the gold/tellurides bearing sulphide ore of the Kensington deposit (Echo Bay Mines and Coeur d'Alene Mines), and to compare the performance of column flotation to conventional "mechanically agitated" flotation, Tests were conducted in a 150 mm diameter, 60 liter glass column with ground flotation feed split from a concurrently operating conventional pilot plant, thus permitting direct comparison between the two processes. During the test program, the effects of wash water rate, gas holdup, froth depth, residence time and flow bias were examined in detail. The bulk metallurgical ore sample had an average "as tested" feed grade of about 5 git gold and 1 % sulphur, with the gold occurring primarily as inclusions of montbrayite (Au2Te3) in pyrite, with minor amounts of native gold. Conventional flotation using 60 minutes residence time across four roughing stages recovered about 97% of the gold into concentrates grading about 50 g/t Au. A single stage of column flotation roughing using 25 minutes residence time matched the conventional circuit recovery of97%, but produced grades of +150 git Au.

Jan 1, 1992

By Darryl J. Butcher

The Akjoujt Project is operated by MORAK SA, a company incorporated in the Islamic Republic of Mauritania. MORAK is jointly owned by General Gold International SA (A wholly owned subsidiary of General Gold Resources NL.), SAMIN, and the International Finance Corporation. The project was devel­oped to treat approximately 2.1 million tonnes of TORCO (Treatment of Refractory Copper Ores) tailings containing an average 3.2gAu/t, and 0.75%Cu/t. The process involves the use of ammoniacal cyanidation for gold extraction, and conventional carbon adsorption, and eventual desorption, of gold values. This is believed to be only the second commercial application of this leach chemistry in the world. The other being a small vat leach operation on the Paris Mine Dumps. (This operation was described by Mr M Ruane in a paper to a previous Randol Forum.) Initial work on the process, and the Akjoujt process design assumed that the reaction involved was anaerobic. This paper describes the operating experience, plant trial, and eventual installation which has lead MORAK to the conclusion that the process is not anaerobic, but requires oxygen, or an oxidant to proceed.

Jan 1, 1995

By Blake M. Paterson

The increasing global demand and lower price of gold has resulted in more advanced gold extraction techniques. One trend is the use of oxygen in place of air in the leaching process, which is proven to significantly enhance recovery of gold ore refractory in such techniques as CIP and CIL. This has resulted in a search for more reliable and cost efficient paradigms of oxygen supply. Many gold mines already realize the heightened recovery rate achieved with oxygen. Previously this benefit had only been available to the largest consumers of oxygen, near oxygen production facilities. Requirements of (1) to (20) metric tons per day have traditionally been supplied with expensive, delivered, liquid oxygen. Since many mines are located in remote areas, it is difficult to secure cost effective and continuous supply of liquid oxygen. However, the benefits of On-Site Oxygen Production combined with a self-generated bulk reserve supply are now available to mine sites. This paper explains and discusses the use of on site Pressure Swing Adsorption (PSA) oxygen production, coupled with a cryogenerator to liquefy oxygen for storage. This package offers continuous oxygen supply to mining sites in even the most remote corners of the world.

Jan 1, 1997