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By N. Damiano, C. Zhou, B. Whisner, M. Reyes

"The industrial Internet of Things (IIoT)—a concept that combines sensor networks and control systems—has been employed in several industries to improve productivity and safety. NIOSH researchers are investigating IIoT applications to identify challenges of and potential solutions for transferability of IIoT from other industries to the mining industry. Specifically, NIOSH has reviewed existing sensors and communications network systems used in U.S. underground coal mines to determine whether they are capable of supporting IIoT systems. The results show that about 40% of the installed post-accident communication systems as of 2014 require minimal or no modification to support IIoT applications. NIOSH researchers also developed an IIoT monitoring and control prototype system based on low-cost microcontroller Wi-Fi boards, to detect a door opening on a refuge alternative, activate fans located inside the Pittsburgh Experimental Mine, and actuate an alarm beacon on the surface. The results of this feasibility study can be used to explore IIoT applications in underground coal mines based on existing communications and tracking infrastructure. INTRODUCTION The nation’s approach to health and safety in mining has historically been reactive in the sense that health and safety regulations and mandates have traditionally been passed as a result of tragic mining accidents. An example of this is the Mine Improvement and New Emergency Response Act (MINER Act) of 2006, which was passed as a result of several mining accidents where tracking of and communications with underground personnel were severely limited. While this reactive approach has led to the development and implementation of highly impactful safety interventions and safety practices, there currently exists a technological revolution that can shift the paradigm toward a proactive approach based on preventative methods: Internet of Things (IoT). IoT is the network of physical objects or ""things"" embedded with electronics, software, sensors, and connectivity to enable that network to achieve greater value and service by exchanging data with the manufacturer, operator, and/or other connected devices [1, 2]. It should be noted that IoT has been defined from various perspectives, and hence numerous definitions exist in the literature. The apparent ambiguity of the IoT definition might be due to the fact that IoT is syntactically composed of two terms: internet and things. The first one pushes towards a network-oriented vision, while the second tends to put the focus on generic objects. The traditional internet can be viewed as an internet of computers —i.e., “things” connected to the internet are computers only. IoT “extends” the internet by allowing other generic things that are commonly found in our daily life, such as refrigerators and cars, to be interconnected via the internet, and thus creates a bridge between the virtual word and the physical world."

Jan 1, 2017

By F. A. Campbell

This paper reports on mineral facies, ore textures, distribution of iron in sphalerites, and fractionation of sulfur isotopes in the Anvil ore body, Yukon Territory, Canada. Because the detailed structure and stratigraphy, both regional and local, are being studied by the geological staff at the mine and members of the Geological Survey of Canada, these topics will be discussed only briefly. The results of our study of the Anvil ore body have implications on theories of the genesis of ore deposits of this type, and these will be discussed. The Anvil ore body is the largest and most significant of three lead-zinc discoveries in an area of the central Yukon where major lead-zinc deposits were unknown only twenty years ago. The Vangorda deposit consisting of 22 million tons was discovered in 1953, followed in 1954 by the Swim Lakes deposit consisting of 10 million tons. The Anvil deposit, which consists of three ore zones, was discovered in 1964. The total reserve at Anvil mine is 63.5 million tons, with an average grade of 3.4% lead, 5.7% zinc, 0.16% copper and 1.2 ounces of silver per ton. This study is concerned primarily with the number one ore body which is about 2,400 feet long, up to 1,100 feet wide and 300 feet thick.

Jan 1, 1973

By K. Ananthpadmanabhan

Hydrolyzable surfactants such as fatty acids and amines undergo, in addition to micellisation and precipitation, various associative interactions in aqueous solutions to form ion molecular complexes such as acid-soap, dimers etc. depending upon the solution conditions such as pH. The interaction of these collector species with the mineral surface and with other dissolved species in solution will play a significant role in determining the interfacial processes such as adsorption and flotation. Marked differences in the hydrophobicity imparted to the mineral surface depending upon the solution conditions such as Ph can be attributed to possible differences in surface activities of the above complexes. This aspect of solution chemistry of flotation systems is discussed here for two widely used collectors namely, oleic acid and dodecylamine. Equilibrium species distribution diagrams based on the available literature .data and on estimates of energy of interactions between molecules, have been obtained for oleic acid and dodecylamine solutions.

Jan 1, 1978

By T. Yue, Z. Gao, X. Tong, R. Liu

"Lead ions (lead nitrate) were introduced to modify the surface properties of scheelite, effectively and selectively improving the flotability of scheelite, with benzohydroxamic acid (BHA) serving as the collector. A series of experiments about the mode of addition and the ratio of lead ion to BHA were conducted and indicated Pb-BHA complexes were the active species responsible for the flotation. And two adsorption models of BHA on the surface of scheelite were established. For both the two adding methods, some kind of complexes formed by lead ions and BHA played a key role in the flotation process. Zeta potential, FTIR, and XPS studies indicated that the adsorption amount and intensity of BHA on the surface of scheetlie were larger by adding the reagents as a mixture. The mixed addition is conducive to form Pb-BHA complexes and improve the adsorption efficiency of BHA on the surface of scheelite, as well as the recovery of scheelite. INTRODUCTION Scheelite, as an important tungsten-bearing mineral, is nowadays utilized mainly by flotation (YIN and WANG, 2014; Sun et al., 2011; Gao et al., 2015; Gao et al., 2015). Flotation separation of scheelite from calcium minerals creates difficulties because of the existence of the same cation in the minerals and similar physico-chemical characteristics such as solubility, hardness, specific gravity, point of zero charge (PZC), etc. (Arnold and Warren, 1974; Deng et al., 2016; Deng et al., 2015; Ozcan and Bulutcu, 1993a; Yongxin and Changgen, 1983). The conventional collectors used in the flotation of scheelite ores are generally fatty acids or fatty acid derivatives (Bo et al., 2015; Oliveira and Sampaio, 1988; Shi et al., 2014; Sivamohan, 1988; Yongxin and Changgen, 1983). It is difficult to separate scheelite, especially from calcite, with these reagents because the adsorption mechanism of these collectors occurs through chemisorption of the oleate ion onto the mineral surface (Atademir et al., 1979; Changgen and Yongxin, 1983; Hiçyìlmaz et al., 1993; Hu et al., 2011). Therefore, it is almost impossible to separate them by fatty acid flotation without using any selective depressant. Although oleoyl sarcosine was used as a selective collector in the flotation of fluorite and siliceous scheelite ores (Ozcan and Bulutcu, 1993b; Ozcan et al., 1994), this selectivity is inadequate for a low-grade calcitic scheelite ore. Unfortunately, reagents such as organic colloids (dextrine, starch), quebracho, sodium phosphates, sodium silicate solutions containing polyvalent cations (hydrosols), etc. (Bo et al., 2015; Schubert et al., 1990; Shi et al., 2014; Yongxin and Changgen, 1983), used for calcite depression also depress scheelite to a large extent. Cationic collectors, such as amine and quarternary ammonium (Yang et al., 2015) and collector mixture (Gao et al., 2015) have been used to improve the scheelite flotation. However they have not been applied in industry due to the poor separation from silicate minerals."

Jan 1, 2017

By B. Arvidson

Computer-controlled machine sorting may, if properly applied, have a dramatic effect on overall economics of a mine operation. Radiometric and photometric sorters have been used for many years and new developments will be reported, such as a sorter for fine particles and a conductivity/magnetic sorter. Application examples with emphasis on precious metals will be given. Economics for some of the projects will be reviewed and discussed. Sorting underground is shown to be particularly attractive, but machine sorting would be profitable in most cases based on savings in transportation and milling/beneficiation costs only.

Jan 1, 1987

By James E. Myers

This study is a survey of the current "state-of-the-art" of commercially-available sonar tools to monitor the true shape of man-made cavities within the Hutchinson Salt of south-central Kansas. The work entailed ferreting out the available information, most of which is proprietary in nature; then examining actual existing conditions and arriving at a reasonable scientific evaluation of the method. Our studies were confined to one LPG field and two brine well operations in south-central Kansas. No field testing of any devices was performed, only questioning user firms, and studying cores, logs, and sonar surveys graciously made available by the companies we have contacted. Since these data are still somewhat proprietary, the company participants have asked that their company names be omitted from this presentation.

Jan 1, 1973

By W. K. Dressel

Over 2 million tons of steel furnace dusts are produced each year in the United States. Recycling of these dusts rather than disposal would conserve mineral resources, reduce land requirements for disposal, and decrease pollution. In addition to the iron content, the dusts contain appreciable amounts of zinc and lead. Removal of lead and zinc with simultaneous reduction of Iron oxide has been achieved by inert atmosphere roasting of carbon-containing pellets prepared from steel furnace wastes. High- and low-carbon wastes were blended to obtain mixtures with sufficient carbon to serve as a reductant during subsequent roasting. The mixtures were pelletized with the addition of bentonite and water, and the dried pellets were roasted in a stream of nitrogen at temperatures ranging from 900" to 1,150° C. Zinc and lead contents were reduced to the 0.1 percent level or less by roasting mixtures containing as little as 7 percent carbon for 1 hour at 1,100° C. ton metallization increases with available carbon content; 50 percent metallization is achieved with 7 percent carbon, 85 percent metallization with 12.5 percent carbon, and over 95 percent metallization when the pelletized mixtures contained in excess of 20 percent carbon.

Jan 1, 1973

By Richard L. Gordon

At almost no time since the end of World War I has the coal industry been free from serious threats to its competitive position. At present, the critical question is whether the industry can maintain its position in the electric power market and this paper reviews the prospects in this area. Our report is part of a study, supported by Resources for the Future Inc., dealing with coal demand in general. Like most elements of coal economics, it has received much less analysis than problems in other energy sectors--a defect we felt worth correcting. We have concentrated on electric power elements of the market. The nature of the coal market makes this the natural choice. Three markets absorb over 80 per cent of coal production and are considered in our overall work. The completely excluded sectors are largely catchall categories in which coal use is declining anyway. Comparing the three markets included in the overall study, we see: modest growth is the most optimistic forecast for metallurgical coke; export growth depends to a large extent on policies of foreign governments. Electric power use, however, has rapidly grown to absorb over half of coal output and coal's prospects depend almost entirely on continued expansion of this market. Throughout the 1960's the demand for coal used to generate electrical power in the United States grew at an average rate of 6.5 per cent annually. This growth rate will be sustained until at least 1976.

Jan 1, 1971

By Robert A. Cummings

A field inventory was made of the mineral, geologic, geothermal, and groundwater resources of three geologically recent lava fields in the desert of Oregon. The term "resource" was applied with care: a "resource" must have particular value or worth, although it need not be economically viable. The spectacular volcanic features of the area have particular scientific and general interest and thus constitute geologic resources. The mineral endowment, mostly occurrences of low unit value such as stone and cinders, in large part are not resources, due to market conditions, regulations, and other factors. These and other conclusions will be used by the Bureau of Land Management in its multiple land use planning process for the area.

Jan 1, 1980

By Tom Learmont

The importance of coal in solving our energy problems has been widely discussed; the world demand for food requires increased fertilizer production and the minerals to produce fertilizer must be mined. We have seen an explosive increase in the demand for large stripping equipment. It is appropriate that we review this equipment and determine what can be done to improve productivity. While we have used coal mining as an example in the study, much of the discussion will apply equally to other forms of stripping.

Jan 1, 1975

By Koichi Nishimura

Japan's coal reserves are estimated at 8,583 million tons (according to the materials on X World Energy Conference,. 1976). Japan is a long island country in the shape of an elongated cashew nut whose top is pointing to the north and its lower tip is pointing to the west. And her major coal fields are located in the two extreme far parts of Hokkaido in the north and Kyushu in the south. On the other hand, Japan's major industrial center are located in the central part of the country far from either coal-producing areas. This fact places coal a great geographical disadvantage in comparison with petroleum whose refining bases are concentrated on the coastal regions virtually next to major industrial centers.

Jan 1, 1982

By Saurav Kumar, Akshay Kumar, Vinayaka R. Kiragi, M. K. Banerjee, Amar Patnaik, Vinod Kumar

Today’s industrial technology offers to optimize and reutilize the resources available in terms of scum that remains after hot rolling in steel rerolling mills in Rajasthan, India. Vast reserves of low-grade coal exist and tons of mill scale are produced everyday after hot rolling in steel rerolling mills in Rajasthan, India. The present research work aimed to optimize the various parameters of solid-state reduction of mill scale using low-grade coal from Rajasthan, India. This study investigates the effect of reduction temperature (850–950 °C in steps of 50 °C), reduction time (60 to 180 min, in step of 60 min), mill scale size (800– 300 μm), and mill scale to coal ratio (1:1, 1:2 and 1:3) on achievable metallic iron percentage and its metallization. A higher percentage of iron content is obtained at a lower particle size of 300 μm. The structural analysis is carried out on 300 μm mill scales using XRD analysis, which shows the percentage of iron is approximately 63%, and metallization above 80% can be obtained under the reduction temperature at 900 °C for 180 min, for 1:3 ratio (mill scale to coal ratio). The chemical composition of the mill scale is obtained using X-ray fluorescence (XRF), and particle sizes as well as distribution of mill scale are determined by scanning electron microscopy (SEM). The elements present in the mill scale are also verified using EDS, which indicates the presence of a major portion of Fe, followed by Fe2O3, Si, and C, respectively.

Aug 14, 2020

By Sunfangze Liu, Xumeng Chen, Yongjun Peng

Efficient separation of naturally hydrophobic gangue, such as talc and carbonaceous materials, from sulphide minerals in flotation is becoming a significant challenge in many processing plants due to the need to process lower grade and more complex ores. Considering the hydrophobic nature of these gangue minerals, prefloating them at the beginning of the flotation circuit in the absence of collectors and rejecting the concentrate is a common practice to remove these gangue minerals. However, sulphide minerals, such as chalcopyrite, can become naturally floatable due to surface oxidation and therefore may float together with naturally hydrophobic gangue. In this study, a new approach was developed to maximize the prefloat of hydrophobic gangue while minimizing the loss of sulphide minerals. The new approach introduced a prefloat cleaner stage where sulphide minerals recovered to the prefloat concentrate was depressed and separated from other hydrophobic gangue minerals at a low pulp potential with the prefloat cleaner tailing fed back to the main sulphide flotation circuit. Flotation tests were conducted using chalcopyrite and organic carbon. The results show that the proposed approach can significantly reduce the loss of valuable minerals in the prefloat flotation without affecting the reject of naturally hydrophobic gangue. Applying pulp potential control at the prefloat cleaner flotation stage also reduces the consumption of reducing agents while minimizing the effect of reducing agents on downstream rougher flotation.

Nov 23, 2020

By Ryan C. Stephan, Zach Agioutantis, Christopher Mark

During the past 15 years, roof fall rates have fallen dramatically in US coal mines, particularly in regions where the roof is weakest. The remarkable reduction in the number of roof falls has been accomplished with more effective roof support systems. The purpose of this paper is to present a design methodology that builds on and quantifies the basic roof support concepts that have been successful in the USA. The methodology starts by defining three modes of roof support, based on the roof strength relative to the stress level: (1) suspension, where roof bolts mainly provide skin control for strong roof; (2) beam building, where moderate strength roof can be supported by roof bolts alone; and (3) supplemental support for weak roof. Next, a large database of roof fall histories at a number of mines is used to define the approximate boundaries of these three regimes based on the coal mine roof rating and the depth of cover. Finally, guidelines are presented for site-specific design of support systems within each regime. The new computer package, analysis of mine roof support (AMRS), implements the design methodology.

Sep 29, 2020

By S. K. Pan, R. Venugopal, L. A. Kumaraswamidhas, Rakesh Prasad, Chandan Pandey

Cold compressive strength (CCS) and apparent porosity (AP) of pellets are essential properties regarding the burden of blast furnaces. The optimal required values for industries are 2.5 KN CCS and 21% AP. Blaine fineness and firing temperature are the decisive parameters analyzed here. During firing, microstructure phases such as silicate, hematite, and pore are formed. The phase’s grain density during induration influences the pellet’s CCS and AP. The influence of the factors over the response is evaluated by I-optimal (response surface methodology) design. Blaine fineness, firing temperature, pore phase grain density (PPGD), silicate phase grain density (SPGD), and hematite phase grain density (HPGD) affect the CCS and AP of pellets. The RSM-I-optimal predicted responses with a coefficient of determination (R2) of 0.89 for CCS and 0.91 for AP of iron ore pellets. Optimal conditions were Blaine no. = 1668 cm2/g, 1250 °C firing temperature, PPGD value 90 no/mm2, SPGD value 250 no/ mm2, and HPGD value 490 no/mm2, with 4.5 KN CCS 27%. The induration processes were investigated through statistical design of experiments for process optimization. Statistical analysis indicated the direct and interactive influence over CCS and AP. In this study, RSM-I-optimal modeling is used for iron ore pellets processing. The I-optimal prediction could be applied to make the process economical because information is obtained through fewer experiments.

Aug 18, 2020

By Keith A. Heasley

Historically, the surface subsidence over underground coal mines has been predicted using empirical profile or influence functions which have little or no connection to the actual mechanics of the subsidence. Without a mechanistic basis, establishing the exact site-specific parameters to use in these empirical methods has been problematic. A practical subsidence predictive method based on mechanics has the appealing capability of allowing the determination of site-specific parameters from fundamental properties of the overburden with minimal field calibration work. This paper presents several case studies where a mechanics-based, boundary-element program is used to back-calculate the surface subsidence associated with various panels at several Northern Appalachian coal mines. The program used in this case study is called LAMODEL, and it incorporates a frictionless, laminated overburden into a general purpose displacement-discontinuity code primarily designed for calculating the stresses and displacements in coal mines or other thin scam or vein type deposits. In this paper, the program is used to calculate both the underground convergence and the resulting surface subsidence at five longwall panels and a room-and-pillar section. The fitted subsidence from the model is compared with the field measurements and analyzed. The results from the case studies in this paper demonstrate that the laminated model with calibrated properties can easily provide moderately accurate subsidence predictions and is fairly flexible for fitting measured subsidence. However, additional subsidence predictive case studies arc recommended in order to ultimately evaluate the potential of the laminated overburden model for practical subsidence prediction

Jan 1, 1999

By Yi Luo, Jianwei Cheng, Mingming Li, Lei Xiao

Concealed thermal events in longwall gobs present safety hazards for underground coal miners and can significantly interrupt mining production. The probable causes for such thermal events range from coal oxidation at slightly above ambient temperature to smoldering fires due to spontaneous combustion of the broken coal left in the gobs. Locating such “hot spots” is the key step for planning and implementing mitigation measures to bring such thermal events under control. If a mine section, or even an entire mine, has to be sealed, understanding the status of the sealed mine atmosphere is important for the decisions guiding subsequent actions. The gas composition data obtained through the tube bundle mine atmospheric monitoring system is firsthand information of great value. Fire ratios proposed by various researchers and derived from gas composition data are useful in determining the fire status and even approximating the source locations (Timko and Derick, 2006). However, the applicability of each of these ratios under particular conditions should be carefully evaluated. The use of properly combined fire ratios can enhance the certainty of analysis. The explosibility of a sealed mine atmosphere deserves primary concern for safety reasons during seal construction, idle time and reopening of the sealed area.Mine atmospheric monitoring data from a longwall mine with flame fire have been analyzed. Efforts have been made to identify the possible causes, locations and statuses of these events using the obtained gas data, as well as other ventilation, geological and mining parameters. The effect of injected inert gas to control the events has also been quantified. The explosibility of the sealed atmosphere has been determined using two methods.

Jan 1, 2012

By W. R. Reed, J. D. Potts

This study tests the ability of a new air nozzle system, located under the drill deck shroud, to improve the dust capture of the drill deck shroud. The system consists of three air nozzles supplied with regulated pressurized air and located midway down the shroud in the off-inlet corners of the shroud. Laboratory testing produced operating curves for the system that showed an optimum operating point of 207 kPa (30 psi) and generated respirable dust reductions of 48% to 52% from the drill deck shroud.

Jan 1, 2009

By D. S. Yantek, C. B. Brown

The mining industry is beginning to implement lithiumion batteries (LIBs) to power mine utility vehicles (MUVs) and rubber-tired mantrips (RTMs). However, the ability of LIBs to withstand the harsh conditions for these applications has not been rigorously evaluated. Concerns with the use of LIBs in the mining environment will be discussed including the effects of mechanical shock and vibration, temperature extremes, and moisture exposure. This paper will discuss adverse effects of the mining environment on LIBs and provide an overview of scientific gaps associated with the environmental susceptibility of LIBs used on MUVs and RTMs.

Feb 1, 2024

By Aldin Ardian, Mustafa Kumral, Jagjit Singh

Risk assessment of mining projects is a requirement in the mineral industries. In this process, many risk variables are timedependent, and the only available data are historical time series. Moreover, in the case of a multivariate scenario, conventional forecasting methods fail to capture conditional dependency across the variables, which is important when there is an underlying causal relationship that needs to be modeled for accurate project evaluation. Thus, we investigated the use of copulas to capture the conditional distribution of the factors involved in a mine risk assessment study. We employed a multivariate copula-based time-series approach to model several uncertain variables. The Autoregressive Fractionally Integrated Moving Average - Generalized Autoregressive Conditional Heteroscedasticity (ARFIMA-GARCH) model was used for the conditional mean and copulas were used to model the error distribution, thus capturing the collective variation and dependence pattern across the variables. The method was implemented to model gold prices, copper prices, and the 10-year US Treasury bond yields and to determine the project’s net present value and probability of being economically feasible. The proposed approach can be used for cases where simulation of multivariate time-series is conducted.

Apr 13, 2021