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By G. Robert Moorehead, Peter T. Luckie, Harold L. Lovell, David J. Akers, James K. Kindig

Jigging is a process of particle stratification in which the particle re- arrangement results from an alternate expansion and compaction of a bed of particles by pulsating fluid flow. The vertical direction of fluid flow is reversed periodically. The rearrangement results in layers of particles that are arranged by increasing density from top to bottom of the bed. This response, developed from the many and continuously varying forces acting upon the particles, permits a solid-solid separation more related to particle density and less to particle size than any other "hydraulic-type" process. The stratification is usually carried out in a rectangular, open-top container called a jig, in which the mass of particles (termed a "bed") is supported on a perforated base through which the water flows in alternating directions. The coal particles, in addition to the vertically expanded and compacted bed motion, move continuously, horizontally across the supporting screen. Following the particle stratification, the particle bed is physically "cut" at a desired horizontal particle density plane to separate the desired clean coal product from the more dense refuse. The jig system includes means for continuously introducing the raw coal and for moving the water through the coal bed in a controllable manner, as well as for separating and removing the stratified particles from the system as two or more product streams. In coal preparation, this highly versatile unit operation is applied preferably to a wide size range of particles with top sizes up to 8 in. (20 cm) rather than to a closely sized fraction. In gravity ranges, the process has been applied to gold particles with a density of 19.3 and to coal particles having densities less than 1.30. Single jig washers have capacities from 5 (4.6) to greater than 700 tph (637 t/h) of feed coal. The separation results attainable by jigging have favored this unit operation as optimum for creating a clean coal product as required by steam coal specifications. Al- though the jig is used in preparing coals which are difficult to separate, its limitations to achieve both quality products and high recovery are being recognized in comparison with heavy media-based processes which make sharper separations from feeds having high "near-gravity" contents. The accu- racy of the densimetric stratification in the upper portions of the jig bed are less precise. It follows that coals with more than 10% near-gravity material

Jan 1, 1991

By E. K. Albert

Computer oriented simulation techniques can be effective in the design and analysis of complex mining systems. In fact, a number of computer software products are available for mine systems simulation. While providing a useful tool for the investigation of mine planning problems, the availability of graphic output was limited or non-existent. Computer graphics is a natural extension of mine simulation methods and provides a more dramatic level of understanding and interface with an engineer. With today's high cost of venture development, the need for an easy to use but complete systems model which includes the major elements of mine planning with an interactive graphics interface has never been more apparent. In this paper, the underlying philosophy of design of an interactive interface to a complete surface mining simulation model is described. The basic structures of the surface mining system and the simulation model are discussed. The methods and algorithms used to implement the various subsystems are presented. Practical considerations of the design of displays and user interaction are illustrated, especially as they apply to the application of the package by a mining engineer. A simple example is provided to demonstrate the concepts embodied in the model and to show how a simulation is built from mine data.

Jan 1, 1984

By C. J. Hunter

Prior to the commissioning of the Sansu Sulphide Treatment Plant (STP), Ashanti Goldfields' treatment facilities were capable of producing some 700 000 ounces of gold per annum. Ore sources were underground refractory sulphides, surface oxides and old tailings dams. In order to increase the mines production to 1 million ounces per annum and to accommodate the change in ore sources as surface mining moved into fresh sulphides, a part of the strategy adopted was -the construction of a new sulphide treatment plant with a capacity to mill 2.2 million tonnes per annum and produce 400 000 ounces of gold. The STP has been designed, built and commissioned. and has been in operation since February 1994. The Plant boasts the world's largest Bio-oxidation facility which is capable of treating 790 tonnes of sulphide concentrate per day at a grade of 11.4% sulphur and is currently undergoing an expansion to increase its capacity to 1050 tonnes per day. The following sections describe the reasons for selecting the BioX® Process, the plant design, the commissioning experience and the plant performance to date.

Jan 1, 1996

By John S. Cummings

In this paper the phrase "exploration for blind metal deposits" refers to exploration activities geared to the discovery of metal deposits which cannot be located by visual surface inspection. The word "system" refers to all of the components (people, money, corporations, techniques, etc.) which collectively result in an exploration process. The details of the system or systems which I have employed in exploration will not be discussed because of client relationships. However, some of the more severe problems in exploration result from how the system's components interact and our attitudes as to what exploration data is telling us, if anything. It is these items which will be discussed. Exploration for blind metal deposits, which has been relatively intense over the last 2S years compared to rather minor outlays prior to World War II has often been an uncoordinated assortment of various specialists employing various techniques (see Dickerson -1). In a program geared to the location of blind deposits, the lack of outcropping deposits or occurrences should not be a deterrent to a well conceived and well planned program. The severe cyclical swings in exploration activity, although often coinciding with depressed metal prices, by and large result from the failure of exploration operators to present a coherent and realistic program to management. It is my opinion that the stream of complaints criticizing management for cyclical exploration support are mostly unwarranted, as many of the programs and goals are ill defined. Although depressed market conditions may serve as the catalyst for exploration cuts, the underlying cause is that when the "chips are down", the non-directional, non-specific nature of many programs is revealed. Thus management should not be castigated for eliminating such programs during bad times, but rather they should be castigated for supporting them during boom periods.

Jan 1, 1978

By S. J. Schatzel, J. D. Addis, V. Gangrade, L. L. Chasko, C. A. Hollerich

A ventilation study using tracer gas was conducted at a western US coal mine. The objective of the study was to evaluate the movement of longwall face air exchanges between the face and worked-out area and to document the presence or absence of face airflow pathways between these locations. The mine operator uses a bleederless longwall ventilation system with a back return and a blowing mine ventilation system. The study was conducted on an active panel and included both underground and surface monitoring sites. The study used sulfur hexafluoride (SF6) released as a slug on the longwall face and in the front of the gob inby the face. The velocity of the tracer gas movement in the gob was 0.019 m/s (3.7 fpm). The rate of movement for the overall tracer gas slug averaged about 0.0091 m/s (1.8 fpm). A separate tracer gas test initiated with the release of SF6 into the legs of the first shield showed the existence of more than one pathway of face air in the general direction from the headgate towards the tailgate corner. Maintaining adequate ventilation air on longwall faces is important for worker safety and for the dilution of methane emitted from the face and caved gob. A more detailed characterization of longwall system air and gas movement allows a mine to better assess its ventilation design for controlling gas on the face and in the gob.

By B. J. Huls

The commissioning of a Distributed Digital Control. System for the grinding circuit at Cuajone, was completed by mid August, 1985. Development of a successful strategy, excellent operator acceptability and the visual aspects offered by the display of the central console, improved mill throughput significantly. The inherent features of a digital system enhanced the flexibility in grinding control and allowed the mills and classifiers to be operated at maximum capacity. This paper discusses in detail the strategy development, the production restrictions encountered, and evaluates the overall performance of the digital control system. 1.0 Introduction In November 1976, the Cuajone Concentrator, located on the western slope of the Andes in Southern Peru, was commissioned to treat a nominal 41,000 TPD of ore. A systematic elimination of production restrictions has resulted in a continual increase of concentrator throughput to 48,700 TPD before the grinding control was in- stalled.

Jan 1, 1986

SOLUTION MINING Solution mining techniques present a means of extracting soluble ores, particularly such materials as salt and potash, from horizons which are not accessible by conventional mining. In the process of dissolving materials, it is evident that solution may be complete or partial. In general, the solution mining operations described in the following section relate to complete solution of the desired compound. Even though the solution of material is complete, there may be instances in which insoluble material is present to a large extent either as granular separated particles or as insoluble layers. The process required for obtaining the desired product involves access wells to reach the deposits, sufficient water supply to yield the production goals, and the development of an underground cavity. The process of solution mining, therefore, depends to a great extent on three factors: availability of a relatively pure strata or formation of salt or potash to be mined, access well or wells, and adequate control of the solutioning process so that enlargement of underground cavities can be fairly well delineated. Since halites represent the most general ores mined by this procedure, the considerations which follow are based primarily on the production of sodium or potassium chloride. The producing formations may be in the form of bedded evc~porites wherein the salt member may be some 30 to 500 ft thick or from salt domes in which great depths of salt occur. Solution mining has been carried out to depths of nearly 10,000 ft. The recovery of saturated brine from wells drilled to effect the solution-mining process leads to further processing. In many instances, the procedures are relatively simple and involve simple recrystallieation or fractional crystallieation, while in others more complex flow systems are required before a final product is obtained. The intent of this section is to provide information relative to the basic procedures for obtaining materials which are soluble in water and to acquaint the engineer with the various aspects of the overall problem which in many instances, may become quite complex and present numerous difficulties. The storage of fluids, particularly hydrocarbons, underground has proven to be a very important part of industry operations. Cavities formed in salt provide excellent storage facilities. The formation of well-defined controlled configurations of such cavities has been possible because of better understanding of the solution process, wide experience gained over nearly 30 yr, and improved technology in drilling and completing wells, surveying caverns, and the operation of numerous types of systems. Solution mining techniques will improve in the future. Many facets of the simple operation of pumping solvents and extracting valuable minerals require further study. Developments undoubtedly will occur to further the processes of mining by solution. In addition to those whose names appear in connection with the individual subjections which follow, a major role in assembling and processing the material in this section was played by Dr. D. A. Shock, Central Research, Continental Oil Co., Ponca City, Okla.

Jan 1, 1973

By N. Edmonson

An examination of the statistics of the world phosphate fertilizer industry since 1980 reveals an increasing tendency for fertilizer manufacturing activity to concentrate in phosphate rock mining areas. The economic justification for this resource-oriented strategy is clear. The choice between shipping phosphate rock, a comparatively low-value product, and shipping more valuable finished fertilizers will always be resolved in favor of the latter if cost considerations control the decision. The historical existence of substantial phosphate fertilizer manufacturing capacity oriented toward fertilizer-consuming activities and dependent on imported phosphate rock shows that narrow cost considerations have not always determined the industry's location. One is entitled to ask what conditions have changed to precipitate the observed relocations, and how permanent these changes are. These questions are the subject of this investigation.

Jan 1, 1995

By Evan J. Owen, Virginia T. McLemore

of high specific gravity, resistant minerals that form from mechanical concentration by waves, currents, and winds in marginal-marine environments. These sediments are enriched in critical minerals such as titanium, zirconium, and REE. Cretaceous beach-placer sandstones are found in the Colorado Plateau of northwestern New Mexico. Originally discovered by airborne radiometric surveys for uranium in the 1950s, these beach-placer sandstones are being re-examined with modern methods as potential sources for critical minerals. Selected beach-placer sandstones have been sampled, mapped with ground radiometric surveys, and analyzed with whole-rock and trace element geochemical methods. Mineralogy is being determined with optical methods, XRD, and EMPA. Zircon, rutile, ilmenite, and monazite are the primary heavy minerals of interest found in the studied deposits. Initial results show that the sandstones contain up to 1.4% total REE, 29.4% TiO2, and an estimated 4.9% ZrO2. Chondrite-normalized REE diagrams show distinct light REE and minor heavy REE enrichment, as well as pronounced negative Eu anomalies for each deposit.

Feb 1, 2024

By T. van Sandwijk, G. Van Weert, E. Molleman

This paper reports on test work that explored the dissolution/precipitation reaction: ZnS + 2HCl - ZnC12 + H2S, which is part of a process used in the production of pure ZnS. The research focused on the influence of proton activity on the dissolution of zinc concentrates obtained from the Brunswick Mine No. 12 in Canada (Brunswick Mining & Smelting); the Red Dog deposit in Alaska (Cominco Ltd.); and the Tara deposit in Ireland (Outukumpu Zinc). A comparison between the results of the experimental dissolution as a function of pH and the dissolution predicted by thermodynamics suggest that the three concentrates contained sig¬nificant amounts of the more reactive mineral wurtzite, although XRD analysis showed mainly the presence of the mineral sphalerite.

Jan 1, 1999

By Katerina Adam

During wet grinding the electrochemical interactions between grinding media and pyrrhotite not only accelerate the media wear but also adversely affect the flotation response of the sulfide mineral. A possibility of remedying the adverse effect on its floatability by applying electric potentials to grinding media was examined. Flotation tests, Auger electron spectroscopy and x-ray photoelectron spectroscopy were used to study the surface properties of pyrrhotite. Although anodic polarization of the steels increased the metal loss by corrosion, the flotation recovery of pyrrhotite was increased. In the case of cathodic polarization, the flotation recovery improved in a narrow range of overpotentials. At higher cathodic overpotentials, however, the floatability of the mineral was progressively lowered although the corrosive wear of grinding media might be reduced.

Jan 1, 1984

By Klaydison Silva, Pedro Silva, Letícia Damet

The current situation of the global mining economy is increasingly focused on the utilization of materials previously discarded in the mining process. The waste from the past, through new processing routes, is gaining new contours for use as high-value-added products. The strategic mine planning process has consequently had to adapt to the new economic reality. In standard scenarios, the focus was primarily on mine sequencing aimed at the highest economic return, with all infrastructure allocated as a necessity of mining. This work aims, in strategic planning, to configure and select the best composition of mining structures. The entire Mine-Plant-Waste-Tailings-Products chain will be considered as a factor in the sequencing of a multimine complex, to achieve the most sustainable utilization of the current mines’ waste. The sequencing is based on concurrent flows of process configurations and capacities, structure sharing, and flexibility of feed types. These factors will guide the sequencing, which will be constrained by components such as waste and tailings disposal rates, lithology feed relationships, and especially product composition through market specifications, all while respecting product shipping capacities.

Feb 22, 2026

By G. W. Poling

Chemical and physical properties of thiol collectors are reexamined to compare the prospects of heavy metal-thiolate or disulphide surface reaction products acting as actual collector species. Recent evidences for the existence and importance of each of these types of adsorbed species on sulphide minerals are also discussed. A conclusion is reached that partial coverage by chemisorbed heavy metal thiolate is often sufficient to confer practical levels of hydrophobicity and floatability. Only on a few highly conducting and "noble" sulphides does adsorbed disulphide-type collector oxidation product appear to be significant.

Jan 1, 1976

By Lee R. Martin, Michael R. Taber

Bird Balls™, the latest development in the ongoing battle at mine sites across North America, help to eliminate accidental avian mortality caused by birds ingesting cyanide leachate. Bird Balls™ are a 4-inch sphere made of high-density polyeth­ ylene (HDPE). They weigh 40 grams and are black in color to provide optimum life in UV intense environments. A floating blanket of bird balls totally excludes birds from a liquid surface. Federal agencies that enforce the Migratory Bird Treaty Act do not specify how to keep migratory birds out of leachate basins. Some state agencies, however, specify that a physical barrier must be in place to exclude migratory birds if cyanide levels are high enough to cause mortality. Industry standards for protecting waterfowl now include Bird Balls™ as well as net­ting, detoxification, and heap leach systems designed in such a manner that no exposed solution ponds or channels exist. Hazing is no longer an option. A bold statement to make? Perhaps, but W. R. Jeffress (1990) covers the subject well when he stated that, "Hazing techniques as a whole have not been effective in excluding waterfowl or other species of wildlife from toxic heap leach solution ponds or tailings impoundments. Research and devel­opment of the new 'Star Wars' hazing techniques, such as laser netting and radar systems, are interesting concepts and will pos­sibly offer an alternative to total physical exclusion or neutral­ization in the future. All of these methods are going to have to be thoroughly tested." For those who may want further docu­mentation, we have included a special reference section cover­ing hazing. R. J. Hallock (1990) stated that, "The Fish and Wildlife Service is particularly interested in migratory birds. In fact, a large portion of our effort, nationwide, is focused on migratory birds. Bird habitats are managed directly through the National Wildlife Refuge System and indirectly through other agency programs. We also have a responsibility to protect birds under the Migratory Bird Treaty Act. Most birds attracted to mine ponds are covered under this Act. The only migratory birds not protected under the Migratory Bird Treaty Act are English Sparrows, Starlings, and Pigeons. Since this is a treaty with five nations, the concept of acceptable losses does not apply. It is not a negotiable situation. There are a few exceptions noted in the Act, including prescribed hunting of selected waterfowl, scien­tific collection, and game bird farming. There is no exception for the loss of migratory birds exposed to solutions of cyanide."

Jan 1, 1996

By H. Y. Yang, L. L. Tong

Semicontinuous-flow, multistage biooxidation experiments of a Chinese refractory, high-sulfur gold concentrate were conducted with different pulp densities for gold recovery. The maximum iron, sulfur and arsenic oxidation rates of 90.0, 88.8 and 96.4 percent, respectively, were obtained in the experiments with 5 percent pulp density. The highest gold and silver recoveries of 96.1 and 68.9 percent, respectively, were achieved by cyanidation. The negative effect of high pulp density on biooxidation was related to the decrease of free and adsorbed cell concentrations with increasing pulp density. The data of iron oxidation from the semicontinuous biooxidation experiments were best fitted by a shrinking core model in which the chemical reaction controlled the rate. The dissolution kinetics of sulfur and arsenic were therefore analyzed by a shrinking core model in which the internal diffusion controlled the bioleaching rates. For the quantitative description of biooxidation efficiency, two parameters — mass dissolution rate and volume dissolution rate — were proposed. In the first stage, the mass dissolution rates of minerals were negatively correlated while the volume dissolution rates were positively correlated with the actual pulp density. The iron and sulfur mass dissolution rates decreased with increasing actual pulp densities in the third and fourth stage, while linear increasing relationships between the volume dissolution rates of minerals and the actual pulp density were observed from the second to fourth stage. The highest mass dissolution rates of minerals were obtained in the first stage with 5 percent pulp density. The highest volume dissolution rates of minerals were obtained in the first stage with 15 percent pulp density. Compared to the volume dissolution rate, the mass dissolution rate was more intuitive to reflect the negative effect of high pulp density on biooxidation efficiency.

By Joseph M. Chelini

Today, the two major operating costs of rubber tired off-road equipment are diesel fuel and tires. Mine Management has minimal control over the ever accelerating diesel fuel costs. However, they can exercise control over abnormal tire costs. Fortunately, with available technology and cost analysis methods, experience shows us the outlook for controlling tire costs is encouraging. Most earthmoving operations using off-road, rubber tired haulage and support equipment have abnormally high total tire costs. These costs, utilizing Tire Information Management, have been reduced more than 30%; 20% can often be guaranteed. Management Apathy on the subject of tires in a complex mining operation perhaps can be understood, but management apathy applied to an abnormally high operating cost, of which tires are, begs for a solution.' Tires have been professionally neglected for many years in most mine operations. This is exemplified in the January, 1982 issue of Mining Engineering by Charlie Son in his article Reducing Earthmoving Tire Costs. He compared the efforts to improve diesel engine costs to the same efforts given to earthmover tires.

Jan 1, 1983

Caterpillar recently held two, two-day demonstration programs for its mining customers. The event, billed as MineDemo by Caterpillar, consisted of two sessions held on consecutive weeks at the company's Tinaja Hills proving ground south of Tucson, AZ. The program included several classroom sessions that focused on Caterpillar equipment applications, including the VIMS (vital information management system) and the CAES (computer-aided earthmoving system). Also included were field demonstrations and the opportunity to test drive mining-related heavy equipment, including dozers, trucks, graders, shovels and loaders. Featured at the event were the recently upgraded 785, 789 and 793 C-Series trucks. Caterpillar recently announced the availability of the 136-t (150-st) 785C and the 177-t (195-st) 789C. The upgraded haulers have replaced the respective B-Series models. The 218-t (240-st) 793C was introduced in 1996. It, too, has been upgraded but retains the C-Series designation. While attending the press event, the author had the opportunity to test drive the 793C at the Tinaja Hills test site. It was amazing how well the machine handled. The operation was smooth and the braking system was precise. The cab was extremely comfortable. To see a C-Series truck in action, the author also visited Newmont Mining's Mesquite Mine, located in Cali¬fornia, across the border from Yuma, AZ. The Mesquite Mine operates a new model 785C truck. At the mine, temperatures have been measured as high as 58° C (138° F) in the pit. Needless to say, the ability to operate dependably in extreme heat is an important consideration for the mine operators. An interview with the driver and later with management confirmed that the 785C has worked out well. The driver praised the comfort of the cab and the ease of operation. Management reported significant fuel savings and was impressed by the truck's maintenance features.

Jan 1, 1999

By C. R. DeGennaro, Yongjun Zhang, J. Bickson, J. L. Carr, Chenming Zhou, J. R. Srednicki, B. Lambie, M. Girman, J. A. Galanko

Between 2005 and 2021, surface mining haul trucks were involved in 54 fatal incidents in the United States [1]. Collision warning and avoidance systems (CXS) can help haul truck operators navigate their route safely. The evaluation of CXS object detection performance for surface mining haul trucks relies on the positional accuracy of the ground truth instrument. As part of a holistic approach, researchers from the National Institute for Occupational Safety and Health (NIOSH) characterized the accuracy of a global navigation satellite system (GNSS) that serves as the ground truth instrument to determine object position and velocity in CXS object detection performance testing. We used precision surveying equipment to establish ground truth points for comparison with GNSS data collected for static positional measurements and reduced-scale straightline vehicle dynamic tests. We conducted these tests with real-time kinematics (RTK) and then satellite-based augmentation systems (SBAS). For the dynamic tests, we measured a distance error of 1.34 m (4.40 ft) using RTK and 1.50 m (4.92 ft) using an SBAS. This research will provide CXS manufacturers and CXS researchers a basis for evaluating the positional accuracy of CXS. Note that we did not evaluate any CXS in this experiment.

Feb 1, 2024

By Shinzaburo Kato

In 1977 Kawasaki Steel Corporation (KSC) built No. 6 BF (Blast Furnace) with an inner volume of 4 500m3 as part of our program to produce 8.5 million tons of crude steel a year at Chiba Works. As the primary raw material to be used in No. 6 BF, we decided to use sintered ore, because we were confident in the obvious advantages of our technology developed by that time on sintering and BF operation using sintered ore. At Chiba Works, however, we had no space for the construction of a sinter plant, so we decided to build it abroad. Sintered ore is easily crushed and degradated. Producing sintered ore at a point far away from the blast furnace and transporting it across the ocean was the world's first attempt. To successfully realize it, we conducted a series of fundamental surveys and studies with special stress on the real aspects of degradation of sintered ore caused by long-distance transportation and handling and the ways and means to prevent the degradation. As a result, we decided to build a plant on the Mindanao of the Philippines.

Jan 1, 1982

By S. G. Malghan

Flotation is the primary method for copper minerals separation from porphyry ores. The need to process difficult-to-float porphyry copper ores presents challenges to engineers and scientists in several areas. This paper is concerned with summarizing generalized problems faced in the processing of porphyry ores and treatment methods to overcome the specific problems. Though some of the problems are interrelated the problems have been classified into three broad catagories. The case studies of some of the successful applications of innovative methods to solve problems related to ore mineralogy, metallurgical aspects of ore treatment and process variables show that quite often the problems are solvable by a judicious choice of flotation variables.

Jan 1, 1984