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By M. S. Celik

Beneficiation of boron minerals by flotation with well defined systems has been very little investigated in the literature. The difficulty arises from the fact that boron minerals cover a spectrum of solubilities. Colemanite, a calcium containing relatively insoluble boron mineral, and borax, a highly soluble boron mineral have been used to exemplify the flotation of boron minerals. The floatability of both minerals using sodium dodecylsulfonate and dodecylamine hydrochloride exhibits considerable differences in their response to flotation. This has been ascribed to variations in the solubilities 0f boron minerals and the presence of the cations in the lattice structure. Flotation tests along with zeta potential measurements are used to elucidate the mechanisms involved in the flotation of boron minerals.

Jan 1, 1992

By Xun Luo, Yi Duan

A field trial of by distributed optical fiber sensing (DOFS) technique was conducted at a longwall coal mine in Australia. This investigation was designed to assess the applicability of DOFS for microseismic monitoring in mining. The experiments used commercially available optic fiber cables, geophones and associated data acquisition instruments – a fiber interrogator and a seismic recorder. The fiber cable was deployed in a 300m deep hole and in trenches of approximately 3.5 km long on the ground surface around and across the longwall panel being mined. The results obtained from the experiments have shown that DOFS is able to acquire microseismic data with quality that is comparable to geophones. It has been proven that DOFS can achieve higher spatial resolution for seismicity sensing and higher accuracy for locating events than a geophone network. These characteristics are particularly useful for using DOFS to monitor ground vibrations associated with ground caving processes and rock fracturing events induced by mining and civil engineering. It was also found that far more additional seismic events were recorded by the fibers than by the geophones. Automated data discrimination and processing methods must be developed in order to utilize DOFS for real-time applications.

Apr 26, 2022

By J. Kretschmann, R. Amiri

"The Sangan iron ore mines (SIOM) in Iran are located in a remote area near the Afghanistan border. The SIOM deposit contains a geological resource of 1.1 Gt (1.2 billion st) of mostly magnetite with an iron (Fe) grade ranging from 27 to 61 percent. The Iranian government plans a stepwise development of SIOM in cooperation with private companies to satisfy the growing demand of the Iranian steel industry. Sustainable development is an influential ethical concept in mining all around the world. However, a successful realization of a sustainable development plan is not possible without a foundation on the core values and regarding the specific circumstances of the individual mining country. This paper introduces SIOM and describes sustainable development activities undertaken during its development. From the early stages, these activities have been realized to secure the acceptance of the stakeholders in the region. To evaluate their effects, indicators were filtered to the ones with the highest priority for the stakeholders. Moreover, Islamic values and Iranian regulations and their influences on SIOM were analyzed.Mining industry in Iran The Islamic Republic of Iran holds 68 types of minerals, including salt, sand and gravel, gypsum, chrome, lead, zinc, copper, coal, gold, iron, etc., with 33.5 Gt (37 billion st) of proven reserves and more than 51.7 Gt (57 billion st) of potential resources. Iran is ranked among the 15 major mineral rich countries (1). In accordance with the statistics published by Statistical Center of Iran (SCI), there were 5,316 active mines and 84,922 employees in the whole country in 2012-2013 (2) and, according to the statistics published by Central Bank of Iran (CBI) in 2011, the share of this sector in the gross domestic product (GDP) of the country was 1.2 percent (3)."

Jun 1, 2016

By M. J. Virnig

A flowsheet for the recovery of nickel and cobalt from laterite ores has been developed which involves acid leaching followed by hydroxide precipitation of the metal values and then releaching of the hydroxide cake with ammonia. Investigations of the chemistry of extraction of nickel by LIX® 84-1 and a developmental reagent, XI-84-IT, along with the physical properties of the organic phases are described. Based on these investigations, suggestions with regard to design of a solvent extraction plant and operating conditions are made.

Jan 1, 1999

By Raymond E. Zimmerman

The use of standard dense-media cyclones is well known, as they have been in use for many years. They are especially well suited for operating at low separating densities and for treating difficult coals containing a high percentage of near-gravity at the point of separation. Very few modifications of the basic design have ever been made. The author recently, however, has been interested in the development of a new type of dense-media cyclone that has been produced in Japan. He has observed the testing of this unit and has collected much data which he feels should be of considerable interest to coal preparation engineers. He feels that this unit, called the Swirl Cyclone, may be of substantial value as an alternate to the standard cyclones. It is certainly worthy of further investigation. There has been relatively little written in English-language publications on the Swirl Cyclone. It was briefly described at the Fifth International Coal Preparation Congress. I It has been described in a general manner by the author in two prior publications. 2, 3 This paper proposes to describe this device in more detail and at the same time submit technical data illustrating its wide characteristics.

Jan 1, 1977

By Y. J. Wang

This paper deals with the application of linear programming to the solution of mine ventilation network problems which involve only the controlled splitting of air. An airway whose air quantity is to be controlled to a prescribed value is called a "fixed-quantity" airway. In a network where the fixed-quantity airways are increased in number and are distributed such that the air quantities for the remaining airways are uniquely determined by Kirchhoff's first law, the problem reduces to determining the head losses and locations for air regulators and fans. This is one of the network problems encountered most often in underground coal mines. By formulating Kirchhoff's second law as a set of linear constraints and the total air horsepower supplied by fans as a linear objective function which is to be minimized, the problem is analyzed through the technique of linear programming. Some important properties of the problem are discussed and examples are presented.

Jan 1, 1971

By O. M. Johnson

Barite and bentonite are the two principal components of drilling fluid systems used in the petroleum industry for oil and gas well drilling with rotary-type rigs. Approximately 87 percent of the world's annual production of barite is used in drilling applications. Of the worldwide production of bentonite, an estimated 30 percent is used. The drilling fluid, or drilling mud, to which barite and bentonite are added, performs five distinct functions: Lubrication-The liquid phase of the drilling mud lubricates the drill bit, preventing premature failure of the cutting edges and bearings. it also helps to soften the formation being drilled. Cuttings Removal-A mud system must be able to carry rock cuttings broken loose by the bit up to the surface where they can be removed by mechanical or chemical methods. The fluid's ability to perform this function depends upon maintaining a proper balance between the rate of circulation of the fluid and the colloidal properties required to entrain the cuttings in the mud to prevent their settling to the bottom of the hole. Hole Stability-The pressure exerted by the mud against the wall of the bore hole prevents the collapse of the uncased portions of the hole. Downhole Information-The fluid characteristics of the mud should be such that good cuttings samples, cores and electric logs may be obtained to help evaluate a well's productive zones and potential. Control Oil, Gas and Water Flows-It is essential that a drilling fluid offset any pressure from naturally occurring formation fluids in order to prevent a potentially wasteful and dangerous blowout.

Jan 1, 1980

By J. S. Chung

As part of ongoing deep-ocean mining research, hydraulic transport systems as well as status of deep-ocean mining systems are reviewed in the aspects of manganese nodules and crusts from 800-6,000-m depth. The emphasis of the investigation of hydraulic transport is placed on the shape effect of particles on the pressure gradients and flowrates. Series of tests are being conducted to study the lift characteristics of a 2-phase vertically upward hydraulic transport of 2 types of small solid particles in a PVC pipe of 1-in (2.54 cm) diameter: irregular-shaped silica sands and equivalent spherical glass beads. Pressure drops and mass as well as volumetric flow rates were measured by electromagnetic (EM) flowmeter and mass flowmeter. The particle sizes used are 8-10 mesh. The results in turbulent flow range of 104 < Re < 105 show that pressure gradients or friction factors are smaller for the spherical beads than the sands. The larger the concentration of the particles are, the larger the pressure gradients become. The larger the particle concentration is, the less the effect of particle shape on pressure gradients becomes. The shape effect is greater for the minimum particle transport velocities than for the settling velocities.

Jan 1, 1999

By R. A. Jankowski

Although the number of operating longwall mining systems has remained relatively consistent over the past five years, longwall production levels have increased significantly during this period. Longwall production currently accounts for approximately 50% of U.S. underground coal production. While longwalls are highly productive and offer other advantages, operations employing this method of mining continue to experience dust compliance problems. This increased longwall productivity has meant that far more dust is being produced. An improved understanding of the longwall face ventilation system and advancement of face ventilation technologies are necessary to ensure all face personnel are allowed to work in an environment that is free of excessive levels of airborne respirable coal mine dust. The Dust and Toxic Substances Control Branch of the National Institute for Occupational Safety and Health&apos;s Pittsburgh Research Laboratory has examined several basic principles of the longwall face ventilation system, and has evaluated the effectiveness of numerous improved face ventilation techniques for longwall mining systems. These include identifying improved techniques for measuring face ventilation parameters on longwall mining sections and investigating the fundamental relationship between face air flow and the entrainment and dilution of respirable coal mine dust. Studies have been completed to determine the impact on face dust levels from using belt entry air to ventilate the longwall. Novel methods have been identified to increase the amount of face air flow and to manage face air flow to most effectively minimize face workers&apos; dust exposure. Unique systems of auxiliary face ventilation have been developed and evaluated at full-scale, simulated longwall test facilities. The theoretical and applied aspects of each of these principles and technologies are discussed. Application of these results, throughout the longwall mining industry, as documented from surveys conducted in the early 1980&apos;s and 1990&apos;s, have reduced the health hazard associated with excessive exposure to respirable coal mine dust.

Jan 1, 1998

By K. A. Perry, R. Q. Eades

The University of Kentucky conducted inerting tests and angle of ejection tests on three types of rock dust. A newly developed hydrophobic dust was compared against typical dry and wet dust applications. This new product is designed to alleviate respirable dust concerns for dry dusting and caking issues with wet dusting. Samples for both test types were prepared in a laboratory and subjected to temperature and humidity cycles that are typical of an underground coal mine. Inerting tests were conducted in a 38-L chamber with a 5-kJ Sobbe igniter. Angle of ejection testing was conducted at the University of Kentucky Explosives Research Team’s laboratory in Georgetown, KY. The results of these tests indicate that the newly developed dust has improved results for flame suppression and ejection compared with typical wet dust applications. The significance of these results is discussed with regard to existing respirable dust regulations and the issues associated with caking.

Jan 1, 2016

By Dr. Jack M. Gillette

A system of models which simulate surface coal mining operations has been developed for use in mine planning and economic evaluations. Micromodels simulate individual mine operations for equipment selection and mine planning. Macromodels simulate all operations in the complete mine for economic evaluation of reserves. A cash flow analysis model makes a complete discounted cash flow analysis to deter-mine a required coal sales price or return on investment for evaluation of any mining project.

Jan 1, 1978

By G. Castillo, J. Mortensen

"INTRODUCTION Molybdenite is typically produced as a co-product in the copper ore flotation process. At the Rio Tinto Kennecott Concentrator (RTKC) in Copperton, Utah, the molybdenite is initially floated with copper sulfides and other value minerals producing a Cu-Mo concentrate. This is then separated in the molybdenum plant by depressing copper sulfides and pyrite and floating only molybdenite. The molybdenum plant in RTKC comprises the rougher circuit and several stages of cleaning to achieve a certain grade requirement of Mo. The rougher circuit is where the first stage of separation occurs. Cu sulfides and pyrite are depressed in the rougher circuit by adding NaSH under nitrogen and in the cleaner circuit by adding NaSH under air. The depression of Cu sulfides (and pyrite) by NaSH is related to the redox activity1. It is important therefore to maintain a reducing potential in the circuit in order to achieve effective Cu-Mo separation. If the rougher circuit is under air, like RTKC’s molybdenum cleaner circuits, it is harder to maintain the target redox potential because NaSH oxidizes rapidly in the presence of air thereby increasing NaSH consumption significantly. CU-MO SEPARATION AND ROLE OF PULP POTENTIAL The collector adsorption on copper sulfide minerals is through an electrochemical mechanism2. The collector changes the surface chemistry of the Cu mineral allowing it to float. Molybdenite, or MoS2, on the other hand, floats readily in the presence of a frother as it is naturally hydrophobic. Usually, hydrocarbon oil extenders such as diesel or burner oil are added to enhance Mo recovery. In order to effectively separate Cu from Mo, the collector complex on the copper surface needs to be destabilized or desorbed using a reducing agent such as NaSH or Nokes. As long as the circuit is under highly reducing conditions, the collector remains detached from the sulfide mineral surface allowing Cu sulfide depression. Therefore, it is important to measure the oxidation-reduction potential (ORP) continually and maintain the reducing condition with addition of NaSH. For a given collector each mineral will have a characteristic potential or electrochemical window for flotation to occur3, therefore, it is necessary to reduce the potential outside of this window in order to effectively separate Cu and Fe sulfides from MoS2 minerals2. In RTKC plant, the target reducing condition is between -450 to -550 mV to effectively destabilize the collector and depress Cu and Fe minerals. Typically the dosage of NaSH used in the molybdenum plant could range from 6 to 30 gallons/min (gpm). The high dosage of NaSH could pose risk of H2S exposure. RTKC wanted to evaluate alternatives to NaSH in order to reduce its consumption and minimize risk of H2S gas generation."

Jan 1, 2016

By Staff

"In 2014, the estimated value of total mine production of nonfuel minerals in the United States increased. The quantity of production increased for most mineral commodities mined in the United States, as did prices. Notable exceptions were the declines in prices for most precious metals. Minerals remained fundamental to the U.S. economy, contributing to the real gross domestic product (GDP) at several levels, including mining, processing and manufacturing finished products. Following the reduction in construction activity associated with the 2008- 2009 recession that continued through 2011, the construction industry continued to expand in 2014, with increased production and consumption of cement, construction sand and gravel, crushed stone and gypsum, mineral commodities that are used almost exclusively in construction. Other segments of the nonfuel minerals industries increased as well. Trends in other sectors of the domestic economy were similar to those for industrial mineral production (Table 1).Discussion of mine production is frequently segmented according to the type of materials produced within the broad categories of metals and industrial minerals. Industrial minerals can be further subdivided as construction aggregates and other industrial minerals. The materials with the highest unit values, usually metals, tend to have very low production rates compared with those of many low-valued materials, such as crushed stone or construction sand and gravel. Therefore, for discussion and analysis of the performance of the minerals industry in general, the value of production is used rather than tonnage produced. Although the value of metals and industrial minerals mined in the United States are similar, if tonnages are compared, construction aggregates dominate, dwarfing the production of all other minerals combined.Mineral industry performanceThe estimated value of nonfuel mineral raw materials, including metals and industrial minerals, produced at mines in the United States in 2014 was $77.6 billion, a 3.5-percent increase from $75 billion in 2013 (Table 2). Net exports of mineral raw materials and old scrap were $15 billion (Fig. 2). Domestic raw materials, along with domestically recycled materials, were used to process mineral materials worth $697 billion. These mineral materials, including aluminum, brick, copper, fertilizers and steel, and net imports of processed materials (worth about $41 billion) were, in turn, consumed by downstream industries with a value added estimated to be $2,530 billion in 2014.In the United States in 2014, mine production of each of 14 mineral commodities was worth more than $1 billion. These were, in decreasing order of value, crushed stone, copper, gold, cement, construction sand and gravel, iron ore (shipped), industrial sand and gravel, molybdenum concentrates, phosphate rock, lime, salt, zinc, soda ash and clays (all types)."

Jan 1, 2014

By Yubo Tu, Lianqi Wei, Tianyi Zhao, Peiwei Han, Zhengchen Li, Shufeng Ye

The effect of oxygen partial pressure on the volatilization percentages of valuable metals from iron-rich pyrite cinder by chlorination-volatilization method using CaCl2 as chlorinating agent was investigated in this study. The volatile products were collected directly and analyzed by X-ray diffraction. It was found that there were CuCl2, CuCl, PbCl2, and ZnCl2 existed in the volatile products. Au and Pb volatilization percentages were almost not affected by oxygen partial pressure. Both Cu and Zn volatilization percentages were negatively correlated with oxygen partial pressure when CaCl2 dosage was no more than 4 wt%, and almost uncorrelated with oxygen partial pressure with a CaCl2 dosage of 6 wt%.

Dec 19, 2023

By G. E. Sreedhar, R. Kumar

The pockets of high silica blue dust across the entire high grade hematite deposits in the Bailadila sector bothers the excavation activity due their iron content, which is higher than the threshold value specified by the Indian Bureau of Mines and the agony of stacking them separately due to their fragile & powdery nature. The physical nature of blue dust and its negligible alumina content makes these a potential source of hematite, which is a blessing in disguise. As most of the particles are in the form of an independent grain making it appropriately suitable feed for dry magnetic separation and thus the dry beneficiation has turned a bane into boon by enabling to produce concentrate either suitable for using as DSO or amenable for blending. The emphasis on carrying out dry beneficiation studies in the present context serves the purpose of mineral conservation, mitigates the issues of excavation and stacking as well as conservation of water resource. This paper describes the laboratory and pilot scale dry beneficiation studies carried out on blue dust of 48 – 60%Fe and Silica up to 30% at 25 Kg/hour to 400 Kg/hour, resulting in production of concentrate assaying 60 – 65%Fe. INTRODUCTION High silica blue dust (HSBD) is associated with Banded Hematite Quartzite (BHQ) and is available in abundance in various pockets across the Iron ore body in the Bailadila region of Chhattisgarh state. High Silica Blue dust occurs in the form of free granular particles and also as friable lumps. The chemical quality of this falls under sub-grade category (45 – 55%Fe) and as per the guidelines of Indian Bureau of Mines, these are to be stacked and conserved as future resources of Iron if it can’t be utilized in the present circumstances. Due to its friable nature, stacking of HSBD is a challenge and it is also compounding the problem by polluting the air under high velocity wind conditions. Because of its physical nature and occurrence in pockets pose challenge to systematic mining. The existing processing set up of the operating mines is designed to treat either Direct Shipping ore (DSO) or Run-of-Mine (ROM) have grade >60% Fe. The present practice of beneficiating iron ore fines (<1 mm) comprise combination of two or more processes such as desliming, hydraulic classification, magnetic separation and flotation apart from requirement of grinding depending on liberation characteristics. The HSBD which is predominantly occur as free granular particles, is significantly low in its alumina content. This gives us an opportunity to utilize them by exploring a suitable beneficiation process so that the concentrate produced can be used as a sweetener for alumina rich iron ore/concentrate. Thus, in the present study, an attempt has been made to adopt dry high intensity magnetic separation technique to explore the amenability of the high silica blue dust for beneficiation.

Jan 1, 2019

By George M. Anderson

The extraction of industrial minerals is usually confined to relatively small mining operations. The recent COSMAR (Committee on Surface Mining and Reclamation) report found that 93% of all mines in the United States were of the small unit variety. Also, of the total number of mines in the U.S. (15,279) 96% were in the industrial minerals (non-metals excluding coal) category. To break it down further, 86% were sand and gravel, and crushed stone operations. Therefore, we are talking about a very large number of small mining operations. If these small miners can afford to hire a college graduate, what kind of training should this person have beyond the normal mining engineering curriculum to best serve the problems that he or she will encounter?

Jan 1, 1981

By J. Carr

Ring gear and pinions used as the final drive on large metallurgical grinding mills are expected to transmit their rated horsepower reliably for long periods of time. Duty is 24 hrs./ day. Life expectancy of such gear sets is of the order of 20 years; that is, each gear and pinion flank is expected to resist failure by pitting for 10 years. This means that for a dual pinion gear set having a ratio of 18.42:1.0 and a mill speed of 10 RPM, every gear tooth will see 105.12 x 106 surface contact stress cycles and every pinion tooth will see 968.15 x 106 surface contact stress cycles in a 10 year period. The allowable surface contact stress on the gear and pinion is determined by the material hardnesses. The rule being the higher the hardness, the higher the allowable surface contact stress may be.

Jan 1, 1985

By J. A. Bartnik

Flocculation, the process of coagulation or coalescence of finely divided particles, is commonly used in separating fine solids from fluids. Forces disposing of the particles to flocculate include: ionic forces of attraction, secondary entropic forces, and magnetism. Magnetic flocculation is due to a physical magnetizing process which affects suspended ferromagnetic particles. Such particles, after exposure to magnetic fields strong enough to cause reorientation of the particles and alignment of the induced magnetic poles, tend strongly to retain this induced magnetism, as the magnetic retentivity of ferromagnetic particles is a linear function of its specific surface.1 Thus, because they become small magnets with high residual magnetism, the particles become and remain attracted to one another, forming large agglomerates. Fine magnetic particles close to domain size can exhibit energies of the magnetization of the order of 105 ergs/cm3,2 which is many times greater than the energy affected by chemical flocculents. Therefore magnetic flocculation can be used to agglomerate particles having surfaces ionized with like charges and only a minute quantity of ferromagnetic material will be necessary to develop sufficient force to overcome the repulsive ionic forces and hold together relatively large masses of fine solid agglomerates suspended in fluids. Since flocculation occurs after the fine suspension passes through a magnetic field generated by magnets surrounding a pipe section, the simplicity of the process and economic advantage makes magnetic flocculation very attractive.

Jan 1, 1971

By A. R. Rule

As part of the Federal effort to help maintain an adequate supply of fertilizer minerals, the Bureau of Mines is conducting research to characterize complex, low-grade western phosphate rock and to develop methods for economic recovery of phosphate. The rock varies from soft, friable, altered phosphatic shale to hard, tightly cemented, unaltered phosphate rock. To supplement current beneficiation by sizing, a flotation procedure was devised that included depression of phosphate minerals with H2SiF6 and anionic flotation of carbonate minerals, followed immediately by cationic flotation of silicate minerals. Application of the procedure to several different ores resulted in phosphate concentrates that ranged from 28 to 31 pct P20S in grade and from 60 to 70 pct in phosphate recovery.

Jan 1, 1977

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.