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By Yanxu Shen, Cheng Liu, Zhijie Chen, Hao Chen, Huimin Gao, Zijie Ren

Fluorite, a kind of critical non-metallic minerals, is the primary source of industrial fluorine. Sodium oleate (SO) is commonly used as the collector of fluorite ores. However, because of its some features (such as the low solubility, high solidifying point, and poor dispersion of SO) at low temperatures, it profoundly inhibits its collecting ability as well as the flotation performance. Herein, we have developed a low-temperature-resistant collector for the efficient flotation separation of fluorite from quartz. The advantages and disadvantages of the SO and sodium petroleum sulfonate (SPS) were analyzed by comparing the performance under different temperature conditions. The results of flotation tests suggest that SPS exhibited much better collecting performance than SO under low temperature. The flotation mechanism of the two collecting agents were further analyzed by contact angle measurements, zeta potential measurements, Fourier-transform infrared spectroscopy (FT-IR), and flotation kinetics. The results indicated that both collectors can selectively undergo electrostatic and chemical adsorption with fluorite, with no adsorption on quartz surface. The sulfonic acid group in SPS is a hydrophilic functional group, which has a relatively higher solubility in water. Therefore, the water solubility of SPS is better at low temperatures.

Sep 30, 2021

By T. H. Bagan

The Sixteen-to-One Mine was originally designed and operated using Blasthole Stoping with end slicing as the primary mining method. This method changed to Modified VCR Stoping in response to efforts to control dilution. The new method combines Blasthole Stoping with shrinkage methods, pillars, and reduced sublevel intervals to provide the most practical dilution control avail- able for low cost bulk mining.

Jan 1, 1987

By Thon T. Gin

The lithologic, mineralogic, and magnetic beneficiation characteristics of the iron formation at U. S. Steel's Atlantic City Ore Mine, Fremont County, Wyoming, have been determined. The iron formation averages about 30 percent Fe content, and varies from 125 feet to about 500 feet in thickness. It is composed of interbedded magnetite-rich quartzites, magnetite-quartz-amphibole schists, and amphibole-chlorite schists. Quartz, actinolite-tremolite, chlorite, and magnetite are the essential mineral constituents. These rocks are differentiated into four major ore types on the basis of their relative quartz and amphibole content. The iron content of the magnetic concentrate decreases and the silica content increases with decreasing grain size and increasing amphibole content in each ore type at the same fineness of grind. Criteria were developed to enable the mine operator to recognize the ore types and to blend them to produce a more uniform concentrator feed. This results in less variation in product quality and requires fewer changes in operating conditions-in the concentrator.

Jan 1, 1965

By M. Misra

The processing strategy for the effective separation of bitumen from low grade (< 10 weight percent bitumen) Utah tar sands by a hot water process differs significantly from that used for the processing of high grade (> 10 weight percent bitumen) Utah tar sands. Excellent separations (coefficient of separation = 0.9) can be achieved for high grade Utah tar sands by intense hot water digestion followed by a modified froth flotation step. Such a technique is ineffective for low grade tar sands. In order to change the characteristics of the low grade tar sand an attempt was made to enrich the bitumen content of the feed to greater than 10 weight percent by recycle of bitumen concentrate to the digestion stage. However the quality of the separation was not improved under these circumstances. Similarly feed enrichment by heat treating the low grade feed with recycled concentrate prior to digestion did not improve the separation. More successful separations of low grade Utah tar sands were finally achieved by modification of the viscosity of the low grade bitumen with controlled addition of diluent. These results of the hot water separation tests and variations in the quality of separation are interpreted in terms of the physical properties of the bitumen and the surface bonding forces operative at the bitumen-sand interface.

Jan 1, 1979

By George C. Hawley

Historically, mica usage has been low because of limited availability; as a by-product of many small processors, who have lacked motivation for extensive R & D. The discovery of a 30 million ton deposit of 85-90% pure phlogopite, when existing markets are only 300,000 tonnes annually, forced the search for large volume new markets. Increasing costs of energy, petrochemicals, plastics and glass fibers, and environmental constraints on asbestos usage, have led to new opportunities for mica as a reinforcing filler. Extensive research and developments; in beneficiating, processing and treating mica, has been necessary to satisfy these new markets.

Jan 1, 1981

By P. W. Conrad, C. Todd, N. A. Degerstrom, N. West, R. Kramer

"Surface subsidence caused by underground room-and-pillar mining operations and by solution mining operations have been studied separately but never in combination. In 2008, FMC Minerals began using solution mining at its Westvaco Mine as a secondary extraction method in an area that had been previously mined using the room-and-pillar mining method. Mining regulations require that subsidence associated with underground mining activities be monitored and measured annually. Using Salt_Subsid, a subsidence software package from the Solution Mining Research Institute, and ArcGIS, Esri's mapping platform, researchers at Montana Tech were able to develop a relationship between measured surface mine subsidence and solution mining that can be used at the Westvaco Mine to estimate the production of trona from solution mining operations. Project backgroundFMC Minerals has increased the production of trona from its Westvaco Mine near Green River, WY, using solution mining as a secondary extraction method in an area previously mined using the room-and-pillar method. The area of interest was mined until 2001 with the use of a borer miner at a depth of approximately 488 m (1,600 ft). Currently, FMC determines the amount of trona produced using its solution mining operations by measuring the dissolved solids pumped from the mine. This approach, however, does not account for the location from which the trona was removed.The location from which the trona is removed and the size of the cavern created by the solution mining operations are important to FMC’s mine planning. FMC believed that with proper investigation of the subsidence at the Westvaco test site, a correlation might be found between surface subsidence measurements and the amount and location of trona production from the solution mining activities. The primary goal of this project, conducted by Montana Tech, was to find relationships between the measured subsidence and the solution mining activities. The project attempted to develop an equation that could be used to predict solution trona production based on measured subsidence. The project attempted to model the relationship between the measured surface subsidence and solution mining production using Salt_Subsid, an existing subsidence software package from the Solution Mining Research Institute (SMRI, Clarks Summit, PA) to estimate the location, size and shape of the solution mining cavern. This study would determine the program’s usefulness for locating and developing the cavern created by secondary solution mining activities. The subsidence and production data sets used in this study were collected over a seven-year period from 2008 through 2014."

Jan 4, 2018

By L. D. Boughton

Solution mining projects are conducted through one or more boreholes which penetrate en ore body. Proper drilling, completion and maintenance of the boreholes, therefore, is essential to the success of any solution mining operation. Wells drilled for solution mining encounter problems quite similar to problems encountered by the petroleum industry in drilling, completing and maintaining wells for the production of oil, gas or water. Many of the services developed and much of the experience gained by the petroleum industry is applicable to solution mining wells. As in the petroleum industry, each individual wellbore and ore body in a solution mining project provides its own problems. These vary greatly from well to well, and it is not possible to set down data or outline programs that will apply to all wells. Instead, the design of the drilling, completion, production and maintenance programs should be worked out for each individual well. The purpose of this paper, then, is to generally describe materials, equipment and techniques available for these programs and to discuss the purpose and sequence of their use.

Jan 1, 1971

By George M. Potter

Precious gold and silver markets support substantial activity in the search for and development of improved and unconventional ore and tailing processing methods. The need for such methods 1s strengthened by consideration of increasingly low grade and refractory ores and old tailing reserves. As background for this review of new and unconventional precious metal processing, recent USBM data (1981) show annual world gold production of about 40.8 million troy ounces. In the U.S. about half the 2.8 million ounce consumption was used for jewelry and the arts, 39 percent for industry, and 8 percent for dental purposes. World silver production in 1981 was about 365 million ounces. Domestic usage the same year was about 117 million ounces. More than $ was used for photography and 30 percent for electrical and electronics. By process, about 1 percent of U.S. production of gold came from amalgamation, 66 percent from cyanidation, 31 percent from smelting ores and concentrates, and 2 percent from placers. As for silver, about 11 percent is from cyanidation and 89 percent from smelting ores and concentrates. Evidently the search for innovative and unconventional precious metal processes must include gravity concentration, froth flotation, hydrometallurgical, and electrometallurgical methods. Although smelting processes are equally important, they largely comprise nonferrous metal technology, and are not discussed here.

Jan 1, 1984

By Bobby Michael (Mike) Roberts, G. M. (Mike) Bernard, Ronald R. Kelly

This paper describes Cananea&apos;s successful implementation of the world&apos;s first mobile high angle conveyor (MHAC™) to achieve multiple-lift stacking of their primary crushed (2,500 mtph) low-grade ore. The mobile high angle conveyor answered Cananea&apos;s needs to stack a second lift, 30-meter high, on their Quebalix I pad. The mobile high angle conveyor is a custom unit that was designed by Terra Nova Technologies (TNT) in conjunction with Continental Conveyor and Equipment Company (CCE&apos;s 100th HAC). The stacking system expansion project also includes a rail mounted tripper on the existing overland conveyor and a custom designed "corridor conveyor" to build the corridor for the upper mobile HAC tracks and tail of the existing mobile stacking conveyor. Mexicana de Cananea, part of Grupo Mexico, is a large copper producer in Sonora Mexico and has been in operation continuously for over 100 years.

Jan 1, 2002

By N. Paas

Diesel powered equipment has been operated in underground coal for more than 50 years. According to the Mine Safety and Health Administration (MSHA), there are approximately 3,000 diesel units operating in underground coal mines in the United States. This number is expected to reach 5,000 diesel units in 250 coal mines by the year 2000. Also, there are approximately 5,000 diesel units operating in metal/nonmetal mines such as trona, potash and salt mines: and more than 3,000 diesel units operating in Canada. This increased popularity of diesel powered equipment over trolley wire, electric trailing cable or battery powered equipment is because of improved safety, greater mobility, higher productivity and increased power of diesel equipment.

Jan 1, 1997

By E. A. Sondreal

Requirements of flue gas desulfurization (FGD) for Eastern and Western U.S. coals will not be the same because of differences in coal sulfur content, ash analysis, and beating value. The effects of these differences and of limited availability of water in the West are the subjects of this paper. Eastern and Central bituminous coals are generally high in sulfur and require removal efficiencies in the range of 70 to 90 percent to meet the Federal emission standard of 1.2 lb SO2/MMBtu. Ash in Eastern coals is low in alkali content and is relatively insoluble in scrubber solutions. High sulfur content and market availability make salable product methods more attractive in the fast and Central United States than in the West. Western subbituminous coals and lignites are generally low in sulfur content, however, only a few deposits could reliably meet the Federal emission standard without FGD, Required removal efficiencies generally fall in the range of 0 to 60 percent to meet the 1.2 lb SO2/MMBtu limit. If the standard were raised to 2 lb S02/MMBtu, approximately two-thirds of Western coals could be burned without FGD. Some Western coals contain ash high in alkali, some of which is soluble in scrubber solutions. This complicates scrubber chemistry, but it also provides the meant for displacing some or all of the limestone requirements when only moderate S02 removal is required. Dry areas in the West would benefit from full commercial developement of dry processes of FGD.

Jan 1, 1974

By İbrahim Çınar, Hakan Özşen

Mine workers in heavy and dangerous work are under several physical risk factors, for example temperature, humidity, noise, vibration, lighting and air velocity. Thermal comfort includes parameters such as air temperature, air humidity, air flow rate, radiant heat, metabolic rate and garment insulation. In this study, thermal comfort conditions were evaluated using thermal comfort indices defined as predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) which were determined by measurements taken from an underground coal mine for approximately 100 days. Although the metabolic rate (light work) was kept at 2 met, it was found that predicted mean vote ranged between − 2.58 and 1.68. The predicted percentage dissatisfied index was found to reach 95%. According to the results, it can be seen that thermal comfort may have negative effects on occupational health and safety. The change in thermal comfort index values in the Soma Underground Coal Mine was investigated in detail and the reasons for the changes were determined. Furthermore, determining the optimal working environment for the mine workers was also an aim of this study.

By Raymond K. Will

Computers are becoming increasingly valuable tools in the mining industry as a greater variety of appropriate hardware and software becomes available, combined with greater acceptance by management, Within a given time period an engineering staff can evaluate or design a project to much greater detail and higher accuracy by utilizing computers once suitable programs have been developed. We are all aware that throughout the world the decreasing grade of minerals coupled with increasing waste to ore ratios necessitate larger capacity, longer term mining operations and attendant higher capital costs. Computers can be of assistance in all stages of mineral exploitation, from geologic exploration through mine feasibility studies and design, to marketing and transportation. Because of the high speed with which data can be digested and manipulated by computers, preliminary information from any stage of investigation can be analyzed to assist in further guidance of that stage. By use of preliminary mine feasibility studies, financial forecasts and sensitivity analysis, even information from a far-removed phase such as marine transportation of the product, can help guide the exploration phase to a realistic target.

Jan 1, 1973

By I. Iwasaki

Differential flotation of bulk sulfide concentrates from Duluth gabbro into copper and nickel concentrates could be implemented by first destroying the hydrophobic coating with ozone and then by recovering the copper concentrate with a copper-selective collector. A number of parameters involved in the use of ozone; such as the sequence and the conditioning time of ozone treatment, the pulp pH, and the level of xanthate addition, were investigated.

Jan 1, 1985

By N-h. Mao

We applied kriging (geostatistics) to interpret the structure of basement rock in Yucca Flat, NTS from borehole data. The estimation error for 118 data is 81 m comparable with those based on both gravity and borehole data. Using digitized topographic data, we tested the kriging results and found that the model validation process (Thomas option) on data gave a fair representation of the overall uncertainty of the kriged values.

Jan 1, 1985

By R. H. Weiland

The dewatering of flocculated clay suspensions by compression in a centrifugal field has been investigated. The results are evaluated with regard to both direct applicability to centrifugal dewatering, in solid-bowl centrifuges for example, and indirect applications to gravity sedimentation systems. It is well known that sediment consolidation under gravity depends on structural characteristics such as permeability and on the "self-weight" of overlying sediment layers. An important objective of the study has been to evaluate the self-weight effect using centrifugal forces to simulate consolidation in deep sediments. In this way, small-scale laboratory tests can be used to predict the rates and limits of sediment compression in industrial systems such as thickeners and settling ponds. Experiments have been conducted in which the sediment mass and initial structure were maintained constant while the effective sediment weight was varied by centrifuging at different speeds. The effects of initial structure have also been studied using controlled variations in flocculation conditions.

Jan 1, 1993

By A. L. de Vegt

Hydrogen sulfide is an expensive chemical used in nickel, zinc and copper mining and metallurgical operations for selective recovery and concentration of metals from leach water streams, acid plant blow down streams, refinery electrolyte bleeds and precious metal plant bleeds. Hydrogen sulfide is either produced on site by catalytic reduction of elemental sulfur or transported to the site as liquefied hydrogen sulfide (H2S) or as a sodium sulfide solution (NaHS). Biologically produced hydrogen sulfide has economically very interesting application possibilities in the mining and metallurgical industry. Converting sulfates from waste streams into usable hydrogen sulfide by biological reduction results in operational cost savings in existing lime treatment systems. H2S can be produced biologically for less than $500/ton S. For the past ten years Paques has been engaged in the development and installation of treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. Paques has designed and installed a groundwater treatment system for the Budelco zinc refinery in the Netherlands to remove sulfate and heavy metals. The hydrogen sulfide produced is used for recovery of metals, mainly zinc, from the ground water stream. The system has been operating since May 1992 treating a flow of 5000 m3/d. At Kennecott&apos;s Bingham Canyon Utah copper mine a pilot plant started operation in November 1995 to develop the process for selective recovery of copper from leach water using biologically produced hydrogen sulfide from sulfate containing groundwater. Other pilot plants are operated at DOE&apos;s Pittsburgh Research Center and at Cominco Research focusing on selective recovery of metals.

Jan 1, 1998

By H. B. Miller

Contract Incentives have long been employed in the underground hardrock industry as a tool to influence employee performance, enhance productivity, and control labor costs. While traditionally structured to establish a direct correlation between performance and compensation, many contract programs have evolved into elaborate systems that promote strategies often viewed as independent of productivity. This paper presents the findings of research into these contract incentives and was conducted with the cooperation of 33 mines utilizing a spectrum of employee compensation and incentive programs. Emphasis of this analysis focuses on the types of production contracts observed and their role with respect to employee earnings.

Jan 1, 1994

By E. E. Jones

The lignites of Arkansas, Louisiana and Texas are typically described as muitiseam deposits which contain quantities of day and sand in thin lenses or in admixture with the fuel itself. These materials are often included in the run-of-mine fuel and can have very adverse effects in the end use. Since May of 1982 the Dow Chemical Co. has operated a pilot plant for the beneficiation of lignites. This facility has successfully removed sand, clays and petrified wood from the lignite producing a fuel comparable to or better than the selectively harvested run-of-mine materials. The design, operation and results from this plant were presented by J. H. Everitt at the 1984 Coal Technology Conference.

Jan 1, 1986

By Y. K. Yen

The most serious problem for on-line coarse particle size measurement from a conveyor belt by image analysis is the overlap phenomenon that occurs between adjacent particles. A methodology is developed and described in this paper to estimate the sieve size distribution from the overlapped projected particle images as might be obtained from a conveyor belt. Two aspects of the overlap problem have been taken into consideration. First, several image processing algorithms were studied to find the most suitable technique to separate the projected overlapped particle images for narrow sized particles. These image segmentation algorithms include two-dimensional thresholding, edge detection and Watershed discrimination techniques. The other aspect of the overlap problem is related to the determination of the general kernel function for the partial particle images obtained from the projection of the overlapped particle bed. In this regard, a computer simulation technique was applied to mimic the overlapped particle bed for narrow sized particles, then the general kernel functions of the partial particle images were determined.

Jan 1, 1994