Search Documents

By Mark C. Holton

The mining industry has recently been. - experiencing a difficult period. Escalating costs, lower grades and deeper level mining, are a few of .the reasons' why interactive graphics or CADD (computer aided design and draughting) systems are increasingly being used. CADD systems which support powerful and flexible mining applications have great potential for making all forms of mining more efficient and effective. There are many application programs which address almost every aspect of mining. Most of these programs originated to satisfy a particular need. Graphics and other features were added until they, reached a point where they were commercially viable as a mining package. Because of their evolution these packages, lack many CADD-type features. Today there are powerful personal computers (PC's) and engineering workstations running the best CADD systems available. These systems, support hundreds of applications in almost every discipline. Mining was until recently not well supported by interactive graphics vendors because of the highly variable nature of mining and the lack of common standards. Users of CADD systems have experienced the benefits of CADD and come to expect similar features from graphic mining packages. Several developers of mining packagers have either attempted to include some CADD features or make their packages compatible with one or other CADD system. Mining can benefit greatly From a combination of interactive graphics (or CADD) and the right mining application software.

Jan 1, 1989

By Reed S. C. Rogers

The breakage parameters of phosphate ore were determined by batch first-order grinding studies in a laboratory ball mill according to the procedures described in the text by Austin, Klimpel and Luckie, using a slurry density of 70 weight percent. The results were scaled to five larger mills of 0.56 m diameter by 0.91 m length (2 ft. by 3 ft.), 0.82 m by 1.52 m (3 ft. by 5 ft.), 3.36 m by 7.90 m (11.5 ft. by 25 ft.), 4.41 m by 9.10 m (14.5 ft. by 30 ft.), and 5 m by 11.1 m (17 ft. by 36 ft.), assuming equilibrium ball charges for the full-scale mills. The results were used to predict product size distribustions and capacities for batch grinding in the 0.56 m and 0.82 m diameter mills and open circuit grinding in the 0.82 m diameter and larger mills using a one-large/two-small reactors in series model fitted to the residence time distribution measured in the 4.41 m diameter mill. The simulated results were compared to plant data for ranges of mill capacities. It was found that the simulated product size distributions were in good agreement with the experimental values below the 70% passing sizes, but did not agree so well in the top sizes. The predicted capacities were in approximate agreement with experimental values for the pilot-scale mills, were about 7 percent too high for the 3.36 m and 4.41 m diameter mills and about 25 percent high for the 5 m diameter mill. Use of the Bond method with the measured Work Index of the phosphate ore gave capacity predictions that were 45 to 150 percent too high.

Jan 1, 1985

By John E. Litz, Charles W. Kenney, Wayne Carter

Refractory gold ore pretreatment processes continue to receive much attention. This paper compares the relative economics of treating ores by oxygen pressure oxidation, roasting and bacterial oxidation with or without preconcentration by froth flotation. Capital and operating cost estimates for each method of pretreatment were prepared and these estimated costs and ore sulfide grades then are used to compare the process economics. The study indicates that the most significant item affecting the economics is the amenability of the ore to flotation. The cost benefits of flotation are $10-13 per tonne ore processed (2%-4% s=, 10:1 ratio of concentration). In most cases bacterial oxidation has the lowest overall cost, especially if less than complete oxidation of the sulfides will give acceptable recovery, however bacterial oxidation has yet to be practiced on a large scale. In all situations pressure oxidation shows the highest cost. However, the cost differences between the treatments are small, less than $7 per tonne.

Jan 1, 1990

Fundamental results obtained from research on the properties of the edge surfaces of kaolinite particles (~500 nm) are reported. Of particular significance was the development of the experimental protocol. Well-ordered kaolinite edge surfaces were prepared as an epoxy resin sandwich structure having layered kaolinite particles in the center of the epoxy resin sandwich. Images of the sectioned kaolinite edge surfaces were examined by atomic force microscopy (AFM), and the average thickness of kaolinite particles in this study was determined to be 38.3 nm ± 11.7 nm. Furthermore, the surface charge of the kaolinite edge surfaces was evaluated with a super sharp Si tip. The point of zero charge (PZC) of the kaolinite edge surface was determined to be below pH 4, in contrast to the traditional view that the edge surfaces of kaolinite particles may carry a positive charge at pH 4. This lower PZC of the kaolinite edge surface was attributed to the lack of isomorphous substitution in the silica tetrahedral layer when compared to the PZC for the muscovite edge surface. Our results are consistent with the particle aggregation and flotation behavior of kaolinite, and should provide the basis for improved flotation strategies leading to the efficient recovery and utilization of mineral and energy resources.

Feb 23, 2014

By Yi Yang, CHENGLONG XU, HAORAN LI, YALI FENG, JINRONG JU

Steel slag is an industrial byproduct of steelmaking that is mainly composed of calcium, iron, silicon and magnesium. In addition, depending on the different raw materials entering the furnace, steel slag contains a certain amount of vanadium that is the main source of vanadium production, accounting for 69 percent of the species of the total vanadium raw material [1]. From experience, the production of one ton of steel will generate 1.0 to 1.5 tons of steel slag [2]. However, the utilization efficiency of steel slag is less than 30 percent, and a large amount of steel slag is identified as waste and stacked in tailings. The random stacking of steel slag not only wastes large amounts of limited steel and land resources but also exerts pressure on the environment [3], making it imperative to research the effective utilization of steel slag and recycling of metal resources.

By K. R. Price, M. Gauna

Jim Walter Resources No. 4 mine produces coal through retreat longwall mining at 610 to 670 m (2000 to 2200 ft) of depth. A three entry, total yield pillar, longwall development experimental region was established for three adjacent longwall panels utilizing 6.1 m (20 ft) wide gate section pillars. Presently, the first longwall panel is completed with roadway deformational behavior monitored for a ground control assessment of the mining system. Data illustrate that the total yield pillar gate section design at No. 4 mine is presently comparable to gate section designs having large equal size chain pillars. Ground conditions will continue to be monitored during the mining of subsequent longwall panels in order to determine the ground control implications from multiple panel extraction.

Jan 1, 1986

By L. A. Roe

The year 1867 marks the first year of commercial production of phosphate rock in the United States. South Carolina produced almost all of the domestic output of mineral phosphate until phosphate mining began in Florida in 1888. During the period 1868 to 1949 the total marketed production of domestic phosphate rock was about 186 million long tons of which 71.5 percent was produced in Florida, 18 percent in Tennessee and 7 percent in South Carolina (1). From 1949 through 1960, Florida phosphate rock production has ranged Prom 71 to 77 percent of the total domestic production. Since three-fourths of the domestic phosphate production is from the Florida field, and since most of the phosphate from the Tennessee and Western fields is not processed, but used directly as electric furnace burden, this paper will concern itself almost entirely with water requirements for mining and processing ore from Florida. Figure 1 summarizes phosphate rock production for Florida vs. total United States production over the period 1947-1960.

Jan 1, 1962

By John A. Lombardi

The HW Process Technologies Engineered Membrane Separation (EMS"') technology is a patented system for the removal of multivalent base metal cyanide complexes from cyanide process streams, and EMSni permeate, concentrate and recovery terminology is explained. Specifically, use of the EMS™ system for the removal of Cu(CN)i- and Cu(CN)43- cop­per from cyanide process streams is discussed. The historical "Copper-Gold" processing paradigm of copper related cyanide consumption and complexation and methods to recover copper and copper complexed cyanide from Cu-Au process solutions are summarized. An advanced stage R&D sequential Cu-Au leaching circuit is proposed wherein two PLS streams are generated, i.e., a high copper tenor "first flush" Cu-PLS and low Cu tenor "second flush" Au-PLS. Copper and cyanide recovery from the EMS"' concentrate generated by Cu-PLS EMSTI,f processing by well known acidification processes and lesser developed, but techni­cally feasible, electrowinning processes are projected to be lower cost than similar dilute solution treatments. Gold is described as Merrill-Crowe plant recoverable from the EMS™ permeate stream coming from the Cu-PLS EMS"' process. Gold is also recovered from the EMSTI,f permeate generated by the processing of an Au-PLS bleedstream. The economics of the proposed Cu-Au-EMS"' circuits are estimated as $2/ gpd capital cost for large systems and $1- $3/ l 000 gallons treated operating cost plus royalty.

Jan 1, 1998

By S. C. Bandis, N. Barton

During drilling of deep boreholes, local mechanical failures of the wellbore walls may occur due to the inability of the incompetent overburden and reservoir rocks to withstand drilling-induced changes of the stress environment. At present, borehole failure mechanisms in three-dimensional stress fields are poorly understood. Our experimental investigations based on 3-D physical models demonstrate the stabilizing effect of the intermediate principal stress. The latter may play a dominant role in maintaining the integrity of the stress relieving failure zone around the borehole. However, this will depend on the stress anisotropy, the angle of hole deviation and on the angle of internal friction. Our tests also indicate that the failure zone can accomodate high extensional strains. Finally, relations between the physical models and closed-form elasto-plastic solutions are discussed.

Jan 1, 1986

By Carl E. Williams

During the past two years a computer program called "COPOR," Computerized Open Pit Optimization Routine, has been developed and used for mine planning of several base metal deposits. This routine utilizes a three dimensional computerized block model of an orebody, some economic parameters and operating constraints to locate the mineable or economic limits of the deposit schedule the yearly production from the mine and produce bench by bench ore reserve summaries and maps of the yearly and ultimate pit configurations. The moving cone method is used to perform these functions with a conventional block model. This model is conventional in the sense that each block is assumed to be homogenous; i.e., either ore or waste but not a mixture of the two. Due to the nature of a seam type deposit this approach is not realistic; therefore, revisions have been made to form a new version of the COPOR program. This version has been named "COALOR," Coal Optimization Routine. COALOR contains all of the power of the COPOR program but is equipped to handle the intricacies of coal seam type deposits. The deposit can be composed of a single seam or multiple seams which are horizontal or dipping at any angle. The numerous coal quality values can be incorporated to aid the optimization of the economic pit limits and yearly scheduling.

Jan 1, 1978

By Dapeng Zhang, Brij Moudgil, Shibo Zheng, Chunhui Feng, Wenyi Song, Wending Xiao, Patrick Zhang

Separation of dolomite from phosphate is the most challenging problem in phosphate mineral processing. Over 50% of the future phosphate reserve in Florida contains too much dolomite to process using the current industry practice. The current phosphoric acid production practice requires less than 1% MgO in the phosphate concentrate as the feed material. The Florida Industrial and Phosphate (FIPR) Institute has collaborated with worldwide experts in the field to address this issue. As a result, the industry is now offered three feasible options. Option 1 offers three methods for reducing MgO content in the concentrate from the Crago process, including adding a dolomite depressant in the rougher flotation step, dolomite flotation of the cleaner concentrate, and scrubbing the cleaner concentrate in quartz sand. These methods could reduce MgO content in the final concentrate by 20–40%. Option 2 involves crushing and grinding of high-dolomite phosphate pebbles followed by dolomite flotation at slightly acidic pH using a new collector that does not require phosphoric acid as a phosphate depressant, achieving a final concentrate analyzing less than 0.9% MgO at about 87% P2O5 recovery. Option 3 is a gravity separation technique using an innovative separation jig, and its full potential remains to be demonstrated.

By R. E. Musgrove

At the present time Climax Uranium Company recovers vanadium oxide from carnotite type uranium ores in the mill at Grand Junction, Colorado, The flowsheet of this mill is shown in Figure I. Vanadium is solubilized by a salt roast of the slime fraction of the ore and dissolution is accomplished by a water leach. The metal is precipitated from the pregnant liquor as sodium polyvanadate by heating to boiling and adjusting the pH to 3 with sulfuric acid. The sodium polyvanadate, commonly called, "red caken, is filtered, melted, and cast into thin flakes. This fused flaked vanadium oxide is the material which is packaged for sale. Fused vanadium oxide, marketed by Climax, contains approximately 87% V205, 7% alkali oxide, 0.08% sulfur, 0.03% phosphorus, and less than 0.5% Insoluble. This material is of a lower grade and has a higher alkali oxide content than other vanadium products offered for sale at this time. A typical analysis of a high grade vanadium oxide currently offered for sale by another company is 98% V205, 1 - 2% alkali oxide, less than 0.05% sulfur and less than 0.2% Insoluble. The only reagent consumed in the precipitation of the sodium polyvanadate is sulphuric acid. The total reagent cost is 0.58 cents per pound of vanadium oxide produced.

Jan 1, 1958

By Rob Herr, Irwan Halim, Heather Marsh

This project will expand sanitary sewer within the City of Columbus. It consists of 2.5 mile long, 72-inch finished diameter pipe grouted inside 10.8-foot diameter tunnel excavation in shale. This paper describes the multi-faceted geotechnical exploration to minimize the underground risks. The tunnel will cross below a buried valley with minimum cover of highly weathered rock. The risk mitigation to cross the valley includes contingencies and cost allowances. Provisions to prevent impact on adjacent groundwater resources will be described. Latest construction updates will be provided including contractor alternate shaft support and pre-excavation probing to mitigate tunneling risk below the valley.

Jun 23, 2024

By Robert E. Hershey

The phosphate industry is the fourth-ranking mineral industry in Tennessee; it has an annual value of 13,000,000 and a yearly production of almost 2,000,000 tons of phosphate ore. Tennessee, at present, is second in rank of phosphate production in the United States. In accord with the importance of this mineral commodity, the Tennessee Division of Geology, is conducting a continuing study of the industry' and the raw s, materials upon which it is dependent. Of the three type's of phosphate found in Tennessee, the brown phosphate rock of the Bigby faces of the Bigby-Cannon limestone is by far the most extensive in occurrence and is the only type being mined at the present time. Because of the importance of the brown phosphate ores, our Division has mapped , in detail the outcrop pattern of the Bigby facies of the Bigby-Cannon limestone. The geologic mapping was done by Dr C. W. Wilson, Jr. and others under his super-vision and the geology plotted on 7 1/2-minute topographic maps, with scale of 1 to 24,000 or 1 inch equals 2,000 feet. These maps will be available for use in the near future and will be published later-with complete geologic coverage.

Jan 1, 1960

By M. J. Sapko

The US Bureau of Mines conducted, through joint funding with the Colorado Mining Association, large scale oil shale rubble fire tests to investigate flammability characteristics and different methods of extinguishment. Ignition of large rubble piles was easily accomplished. Foam blankets could he used to control surface flames. The results of these large scale tests confirmed that water was effective but not particularly efficient in extinguishing deep seated oil shale fires. It took up to 1.7 times as much water to extinguish afire as anticipated on the basis of a simple cooling model, assuming 100% utilization.

Jan 1, 1990

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4)-air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway. Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) measured thermal-runaway pressures of lithium iron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 4260 psia (294 bar) of pressure during a thermal runaway, far exceeding minimum pressure containment specifications for conventional explosion-proof enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce thermal-runaway pressures to levels below that expected for CH4-air ignitions. Measured thermal-runaway temperatures were below the minimum autoignition temperature of CH4-air.

By N. B. Greninger, M. J. Sapko

The US Bureau of Mines conducted, through joint funding with the Colorado Mining Association, large scale oil shale rubble fire tests to investigate flammability characteristics and different methods of extinguishment. Ignition of large rubble piles was easily accomplished. Foam blankets could be used to control surface flames. The results of these large scale tests confirmed that water was effective but not particularly efficient in extinguishing deep seated oil shale fires. It took up to 1.7 times as much water to extinguish afire as anticipated on the basis of a simple cooling model, assuming 100% utiliza-

Jan 1, 1991

By F. F. Peng

For a given flotation system, the rate-controlling step in fine coal flotation can be the attachment of bubble to the fine coal particles. The probability of attachment depends upon the surface characteristics and the collector adsorption on the coal particle surfaces. Thus, to further improve the flotation rate and selectivity is to alter the distribution of hydrophobicity on coal particles efficiently by applying the effective means of collector dispersion. In order to enhance the combustible recovery and selectivity of fine coal flotation, and lower the amount of collector used in the fine coal flotation processes, four modes collector dispersion/addition techniques are tested. They are direct liquid addition in pulp (mechanical agitation), ultrasonic energy dispersed collector into pulp, atomized collector into pulp and gasified collector transported by air and formation of collector-air bubbles in pulp. The effect of four collector dispersion/addition methods on the floatability of -600 µ m (-30 mesh US sieve) coal samples from four ranks of coals were studied. The ultrasonic energy dispersed collector and atomized collector flotation processes enhance flotation yield and most significantly improve the kinetics of fine coal flotation. The gasified flotation process can increase the selectivity of separation and decrease the collector consumption due to starvation flotation is achieved in this process. The flotation efficiency of gasified collector process is as high as that of conventional flotation. It is because that the effect of the decrease in the combustible recovery is offset by the increase of selectivity. In addition to flotation experiments, induction times of bubble attachment to the bed of fine coal particles for four ranks of coals are measured.

Jan 1, 1992

By J. Wallace Gwynn

Salt from Great Salt Lake was probably used by the Native Americans prior to the Jim Bridger Expedition to the lake in 1824-25, and was used by the region's early explorers and trappers after that time. From the arrival of the Mormon pioneers in 1847, salt has been produced from Great Salt Lake, starting first with the collection of crude salt from along its shores, and later by boiling down the lake's brine to obtain crystalline salt. Since these early beginnings, salt production from the lake has become a substantial commercial enterprise. Since the early 1960s, research and development have led to the economic production of potassium sulfate, magnesium metal, chlorine gas, magnesium chloride products, and nutritional supplements. Many of the salt-production techniques and equipment that were developed prior to 1964 are still being used today. Sodium sulfate has been produced, but is no longer marketed. Morton Salt, Cargill Salt, and IMC Salt currently extract sodium chloride, which is precipitated during the early stages of evaporation when the brine concentration reaches saturation, or about 26 to 27 percent total dissolved solids. Magnesium Corporation of America produces magnesium metal and chlorine gas, and IMC Kalium Ogden Corporation produces potassium sulfate, as well as magnesium chloride brine and flake products. These salt, gaseous, and metallic products are processed from the sodium-chloride-saturated, high-magnesium-chloride brines, and from the potassium and magnesium salts that are precipitated from the lake brine after it has been further concentrated. One obstacle to salt production is the fluctuating level of Great Salt Lake. In 1983, the lake level began a dramatic rise from an elevation of 4,200 feet (1,280.16 m) to its historic high of 4.211.85 feet (1,283.77 m) in 1986-87 (uncorrected USGS provisional lake-level records). The State of Utah employed flood-control measures, including breaching the Southern Pacific Railroad causeway in 1984, and pumping lake water to a shallow basin west of the lake in 1987. During the high-water years, the lake's mineral-extraction industries faced many challenges including the need to raise dikes to prevent flooding of facilities, broken dikes which resulted in the inundation of solar ponds, and dealing with the lake's greatly reduced brine salinities which resulted in lower annual salt and concentrated-brine production. The years following the record-high lake levels have been a time of adaptation, innovation, and change for Great Salt Lake industries. After its solar ponds were flooded in 1986, AMAX, Inc. built a new solar-pond complex near Knolls, and used the concentrated brines from the West Pond, generated by the State's West Desert Pumping Project. Great Salt Lake Minerals built a 21-mile-long (33.8 km) open, underwater canal, called the Behrens Trench, to convey concentrated brines from a new, remote solar pond on the west side of the lake to the east side of the lake, to help increase its production of sulfate-of-potash. There were also numerous changes in corporate ownership and production-facility locations.

Jan 1, 2001

By David Wright, Jerome Chamfray, Anthony Harding, Brian Boye

Conway’s Law states that unless we intentionally design automation tools around what we need, we will simply replicate our existing processes. While we may achieve some savings this way, there is an opportunity for greater benefits if we re-imagine the way we, as an industry, perform design. This paper examines current technology and shows how even small departures from merely encoding what we currently do could reap significant benefits. From these examples a framework is developed for a new and innovative approach tvo automation that will allow us to design more quickly, to a higher quality, and communicate outcomes more effectively.

Dec 1, 2022