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By Eduardo Pimenta de Melo, Rambabu Pothina, Rajive Ganguli

Sensors are everywhere in the mining industry, with sensor information being used to monitor and operate processes. Therefore, when sensor information is wrong, economic losses can occur. Unfortunately, sensor errors are usually not detected till they become large. This is problematic as most calibrate their sensors no more than once a year (Beamex, n.d.). Using principles of data mining, where all relevant information is tapped to glean hidden information, Pothina [8] designed an algorithm to detect errors in temperature sensors in gold stripping circuit in Pogo mine, Alaska. This paper continued his work by analyzing the behavior of the algorithm on baseline data and testing the algorithm in new data and under more rigorous conditions. It also made a change to the algorithm. The modified algorithm performed very well in the new data. It also worked well under the new error conditions. Three types of errors were seeded, a fixed additive error (+ 2%), a fixed subtractive error (− 2%), and a noisy, normally distributed error, with a mean value of + 2%. Artificially seeded errors were detected within about 20 gold stripping cycles. Inherent bias in operation impacted algorithm performance by increasing the number of cycles needed to detect errors. This paper reinforced Pothina’s [8] conclusion that when data mining approach is used, sensor errors can be detected even when they are pretty low. Significant economic losses can thus be minimized.

By T. E. Gray

This report describes the preparation characteristics of the more significant coalbeds in Butler County, Pa. It is one of a series planned to determine which coals are suitable for producing metallurgical coke, either as mined or after beneficiation. More than 2 million tons of coal was produced in Butler County in 1958, of which about 25 percent was cleaned mechanically in four cleaning plants. Updating the 1942 coal-reserve estimates made by Ashley to December 31, 1958, more than 1,266 million tons of recoverable coal reserves remain in the county in beds that arc 24 inches or more thick. The Upper and Lower Freeport, Upper, Middle, and Lower Kittanning, Clarion, and Brookville beds were selected on the basis of production and estimated minable reserves. Sample locations were chosen after a study of the literature, conferences with mining engineers and mining company officials in the field, and examination of the available sites. Four samples each were collected from the Upper Freeport and Middle Kittanning beds, three samples from the Brookville bed, two, samples from the Upper Kittanning bed, and one sample each from the Lower Freeport, Lower Kittanning, and Clarion beds.

Jan 1, 1960

By Mark A. Williams

Topography and geology greatly impact the decision of how to plan and operate a surface mine. To extract coal, five primary surface mrning methods are practiced in the United States. These include contour strip. mountamtop removal, area, modified area, and open pit mining methods. The first four approaches are commonly associated with coal mining while open pit techniques, although used in the mining of coal, are more commonly applied to the mining of hard rock, metals, and aggregates. Various sub-routines of the primary surface mining methods are likewrse applied rn the industry.

Jan 1, 1991

By L. L. Tavlarides, N. V. Deorkar

"Recovery/Recycling of metal ions from industrial process waste streams is a preferred alternative to disposal by conventional techniques. This paper presents methods for preparation of inorganic chemically active adsorbents to be used in fixed bed adsorbers. Methods for immobilization of chelating agents on the inorganic supports are discussed. The prepared adsorbents are characterized to determine coverage density of functional groups, effect of pH on metal ion removal efficiency, regeneration efficiency and uptake capacity. Results from the laboratory scale and bench scale experiments are presented here.IntroductionRemoval of heavy metal ions from processing wastes in various industries is an important problem. Waste streams in electroplating, electronic, catalyst preparation and hydrometallurgical industries contain metal ions such as copper, nickel, chromium, lead, tin, cadmium, silver, gold and platinum. One major concern for the non-ferrous metal industry is secondary recovery of precious metals and cyanide from cyanide leachate from smelter residue and hydrometallurgical waste streams.Recovery methods recently considered include evaporation, electrolyte metal recovery, reverse osmosis (1), adsorption, ion exchange (2,3), membrane separation (4,5) and Solvent extraction. These processes have met with various levels of limited success. The use of liquid ion exchange molecules to selectively extract metal ions for on-site treatment of these waste streams is currently receiving substantial interest (6,7). This interest seems from an awareness of the advances made in the development of commercial extractants for metal ion separation in hydrometallurgical industries (8). However, separation by solvent extraction processes is generally considered to be economical in the range of aqueous metal ion concentrations from 0.01 to 1.0 mol/lit (9). In order to exploit the selectivity of chelating agents, the idea of immobilizing chelating agent into a solid matrix has attracted growing attention in recent years. Many supports such as inorganic oxides, organic polymers, cellulose powder and polyurethane foam can be used for immobilization of chelating agents. Over the last decade, considerable efforts have been directed toward attachment/introduction of chelating agents into a polymer matrix (10,11). Inorganic supports as compared to polymer supports provide high mechanical strength, chemical and thermal stability, and high reaction rates due to open pore structure. On the contrary, organic resins shrink and swell, thus affecting mass transfer (12). Many of the disadvantages of polymer supports can be excluded by the use of inorganic supports. Innovative use of immobilization techniques can produce inorganic chemically active adsorbents with comparable capacity, stability and reaction rates. Consequently, the objective of our program is the development of inorganic chemically active adsorbents to be used in a fixed-bed unit operation as an alternative heavy metal ion recovery process. Methods of preparation of inorganic chemically active adsorbents, (ICAAs) characterization and applications are discussed in this paper. A brief summary of the results from laboratory scale studies and bench scale studies is presented."

Jan 1, 1996

By Marco Olper

After two years of extensive research a new and innovative modification to the CX-EW process has been exploited. This process, called CX-EWS, avoids completely all the critical aspects of the previous process which affected the cost of the energy, of the chemicals and of The maintenance of the insoluble anodes. All these benefits reflect a saving of about 30% of The operating costs compared to the present traditional production and allow for a total operating costs of less than 6.5 cts/lb. lead (net of raw material cost). With this new technology it is allowed for the first time the treatment in the same plant facilities of both primary lead sulphide concentrate and spent batteries. The paper describes the technical and economical aspect of the new process with a feasibility study for 150,000 t/y spent battery facility throughput.

Jan 1, 1995

By H. C. Roland Kammel

Stannous sulfate electrolytes are widely used nowadays in electrolytic tin production. Characteristic features of this electrolysis process are that dense cathode deposits can only be obtained by additions of organic additives and that so called ?black mud is formed on the anode surface which leads to an increase in cell-voltage. In order to prevent excessive cell-voltages or oxygen evolution the black mud has to be removed periodically. Studies in laboratory scale have been performed about the effect of different organic additives on electrolytic tin deposition and the formation of surface layers on pure and industrial tin anodes. Results reveal that organic addition agents are effective in reducing cathode roughening as well as extending the covering time of the anode ?by black muds.

Jan 1, 1985

By G. E. Rencken, J. H. Potgieter, A. Narain, J. Smith

To conserve fresh water resources and comply with environmental regulations, DRDGOLD, a South African gold producer re-treating surface tailings, has transitioned to a fully closed water circulation system. Consequently, the accumulation of contaminants, as well as addition of reagents, has led to changes in water composition that have compromised leach performance and overall gold recovery. A two-sample t-test confirmed a significant difference in gold recoveries between the use of Rand Water, which was used as a benchmark, and untreated process water. Atomic absorption analysis of ERGO’s process water, confirmed the presence of iron, nickel, zinc, and manganese. A study of the effect of the identified contaminants on gold recovery showed that iron, nickel, and zinc have the largest negative effect on gold recovery, with iron and nickel being more detrimental than zinc. Sulphates were shown to have a possible passivation effect, which also influenced gold recoveries, although to a lesser extent than the heavy metals. Calcium, when present in excess, had a positive influence on gold recovery indicating the possible formation of a calcium aurocyanide complex. Lime softening successfully reduced the heavy metal and sulphate concentrations, and the gold recoveries obtained with the treated process water were similar to those as achieved with Rand Water.

Jul 1, 2021

By J-P Franzidis, E V. Manlap

Froth transportation characteristics have a significant impact on the flotation recovery especially in large flotation cells. The probability of an attached particle being recovered into the concentrate depends strongly on the location where it enters the froth phase. A mathematical model for froth transportation in industrial flotation cells was proposed (Zheng et al, 2004). The model has been tested on the experimental data obtained from testwork conducted at the Western Metals Hellyer lead/zinc concentrator. The results show that the model fits the experimental data well, especially when the froth is well developed (ie for a deep froth). The model fitting can be significantly improved by incorporating an air dispersion factor. However, the models encounter some limitation, ie inconsistent prediction at different froth heights, due to change in froth viscosity which cannot be modelled at the present time.

Jan 1, 2005

By Éder Domingos Oliveira, Carlos Antonio Morais, Ruberlan Gomes Silva

The objective of this study is to assess the impact of different reagents, such as limestone, lime, magnesium oxide, and sodium hydroxide, in experiments carried out in the single purification step and in two consecutive purification steps by raising the pH of a rare earth sulfuric liquor with the aim to remove or reduce the impurity concentrations in the rare earth sulfuric liquor. The choice for the best purification condition was made based on the minimum loss of rare earth elements (REEs), reagent consumption, and residue generation. The exploratory experiments show that it takes place in the two consecutive purification steps, the first one consists in dosing the limestone pulp until it reaches a pH of 3.5 followed by an addition of a lime pulp reaching a pH of 5.0. Under this condition, the results were a total removal of Fe3+, PO4 3− , and Th4+ ions and a reduction of 99%, 87%, and 37% w/w in the Al3+, UO2 2+, and SO4 2− concentrations, respectively, in the purified rare earth liquor. Furthermore, the lowest REE losses (8.3% w/w) and reagent consumption (4.3 kg/m3 ) and also a low residue generation (7.5 kg/m3 ) were observed in this condition. Despite reaching similar results regarding impurity removal, the experiments done with the addition of limestone, lime, magnesium oxide pulps, and sodium hydroxide solution in the single purification step, where the pH was raised to 5.0, presented higher REE losses (64.9%, 42.5%, 44.8%, and 60.9% w/w, respectively) and a higher residue generation (43.2, 25.1, 11.1, and 13.6 kg/m3 , respectively). This occurred due to the co-precipitation of salts containing rare earth elements in their composition. The experiments conducted with limestone, lime, and MgO resulted in a higher consumption of reagents, while the same result was observed when NaOH was used (4.3 kg/m3 ). In the experiments carried out with the addition of magnesium oxide and sodium hydroxide, the respective purified rare earth liquors presented a high concentration of magnesium, sulfate, or sodium, which could impact the quality of the marketable rare earth salts, whereas the salts obtained under the best condition observed in this study seem to be amenable for use as raw material in an attempt to obtain rare earth products with an acceptable chemical quality.

By M. Z. A. Bakar

A series of full scale laboratory linear rock cutting tests was carried out with a long bladed single disc cutter (292 mm diameter, 11mm wide constant cross-section blade) on dry and water saturated sandstone blocks using a linear rock cutting machine (LRCM). The muck collected from the cutting tests has been analyzed to establish a link with the specific energy (SE) of the operation. Coarseness index (CI), a non dimensional parameter, has been found to be a useful indicator of the relative efficiency of the cutting operation. An inverse relationship of the form SE = k CI-n is observed between SE and CI with very high CI usually corresponding with the lowest values of SE. The power n of the relationship for both dry and saturated rock tests is much less than the values found in the previous studies using constant cross section disc cutters and is believed to be dependent on the strength of the rock and the cutter type used. Although the average CI is found to be lower for saturated rock than for dry rock, at the same time saturated rock cutting is found to be less energy intensive (in terms of SE) than dry rock cutting. Moderate correlation exists between the production rate or yield and the SE of the cutting operation for both dry and saturated rock, which can provide some useful information about the field production rate discounting the effect of discontinuities in the rock mass.

Jan 1, 2012

By Knut H. Hubert

The GRATE-KILN System plant at Svappavaara, Sweden, was constructed for LKAB by Allis-Chalmers under a turnkey contract and commissioned in 1969. The plant was designed to produce iron ore pellets from magnetite concentrate at 6100 mtpd using imported fuel oil. It represented the state of the art for plants of its type at the time. Fuel rated capacity was attained within one week of start-up. Product quality, power usage, fuel consumption and machine wear were within warranty limits during sustained production thereafter. As operator skills improved and gas handling system reserve capability was utilized, the plant frequently produced acceptable product at up to 115% of design capacity. During the period 1969 to 1976, market demands increased for high-quality pellets while energy costs rose steadily. At the same time, important advances in the design of GRATE-KILN Systems were being made in other plants constructed by Allis-Chalmers.

Jan 1, 1980

By Scott Ellenbecker

The formation in Newmont Mining?s Phoenix Mine near Battle Mountain, NV contains high levels of abrasive quartzite as well as gold, copper and silver. Newmont started mining operations at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geological formation. But as it turned out, it was more challenging than anticipated. Mine manager Mark Evatz said, ?Anything that touches Phoenix rock wears fast. The rock fights back here.? To contend with the hard conditions, Newmont uses Atlas Copco?s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses Atlas Copco TD65 hammers with 171 mm (6.75 in.) bits. The mine?s PV-271?s are outfitted with a single 41 m3/min (1450 cfm), 2.4 MPa (350 psi), oil-flooded air compressor. Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine?s goal is to keep 3.6 Mt (4 million st) of muck in inventory to stay ahead of the shovels and support needed operational flexibility (ore control related). Drilling efficiency has been a continuous point of improvement since operations began at the mine. The single-pass depth capability of 16.5 m (55 ft) on the PV-271 helped with that. Originally, the plans called for 6-m (20-ft) bench heights, supported by 7-m (23-ft) drill depths, and time spent moving from hole to hole was eating up productivity. Drilling on that plan resulted in drilling an average of 14 m/h (47 ft/hour). When depths were changed to 13-m (44-ft) drill depth, supporting blasting of 12-m (40-ft) benches, they were able to use the single pass capacity of the PV-271. Performance increased to more than 18 m/h (60-ft/hour) an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with improved knowledge of the Pit Viper drills helped as well.

Jan 1, 2009

By D. Michael Holloway

The realignment of Interstate 880 replaces the double-decked (Cypress) viaduct collapsed in Oakland, California during the 1989 Loma Prieta Earthquake. The California Department of Transportation (CALTRANS) evaluated several pile foundation schemes for supporting the proposed structures. Structural support demands led to the selection of steel pipe piles (16-, 24-, and 42-inch-(406-, 610- and 1067-mm-)diameter), filled with concrete and steel reinforcement. Deep penetrations required through layers of very dense/cemented sands in some locations, caused serious drivability and pile integrity concerns. The need for large pile driving hammers and large diameter steel pipe piles pushed the engineers and prospective contractors well beyond the limits of local experience. Such questions as the feasibility of driving the pipes closed-ended through dense upper strata, and quantifying the effects of installation on the long-term capacities of the piles, led CALTRANS to develop a comprehensive pile test program to address the design and construction issues effectively. The results were furnished to prospective bidders on the production stages of the ensuing contracts.

Jan 1, 1996

By T. Lindstad, J. Kaczorowski

The Boudouard reactivity of single cokes produced from selected bituminous coals and commercial cokes has been investigated in a thermo gravimetric furnace. The effect of potassium as a catalyst for this reaction was studied, as it is known to accumulate in ferromanganese furnaces. A gaseous impregnation technique using K2CO3 as the potassium source was applied to impregnate the coke samples. The reactivity experiments were designed to simulate conditions occurring in an industrial furnace, as used for production of Mn-alloys. The coke particle size varied from 3.35 to 6.63 mm, while the temperature was maintained between 800- 1100oC with a gas composition from 50 to 75% CO2 in a CO/CO2 mixture. To determine the catalytic effect of potassium, the concentration varied from a fraction of a percent up to 15%wt. The results show that single chars vary significantly in reactivity, depending on the properties of the parent coal, while commercial cokes exhibit similar reaction rates. Temperature and partial pressure of CO2 have the strongest influence on the reactivity, while the influence of gas flow rate and coke particle size were found to be negligible. The catalytic studies revealed that the relative reactivity of non-impregnated samples are preserved after the impregnation, so the least reactive coke is still the least reactive after the impregnation for the whole range of potassium loads. Also, it has been confirmed that the Boudouard reactivity reaches a plateau at potassium concentration of 4%wt.

Jan 1, 2007

By Ping Yang, Tian-bin Li, Min-hui Wu

"The process of filtrate loss of low solid-phase drilling fluid at different content of polyanionic cellulose is investigated by the standard filtration test. The test results showed that when time of filtration is same, the filtrate volume decreases linearly with the increase of content of polyanionic cellulose. When content of polyanionic cellulose is same, the velocity of filter loss decreases nonlinearly with the increase of time and the velocity of filter loss will reach a stable value. The filtrate volume in 7 to 8 minutes can reach half of the total filtrate volume. At the same time, the velocity of filter loss of drilling fluid decreases nonlinearly with the increase of viscosity. When apparent viscosity is between 3.5~4.15 mPa.s, decrease speed of velocity of filter loss is quick. The results are helpful for characteristics evaluation of filtrate loss of drilling fluid and control of filtrate loss.IntroductionDuring the process of drilling, water of drilling fluid can leakage into stratum, the water can result in instability and collapse of borehole wall. At the same time, the original ratio of drilling fluid will change. The density of drilling fluid will increase, the performance of the drilling fluid will change. Controlling amount of filtration is important to drill successfully. The additives of controlling filtrate loss are mainly two types, particle materials and polymer materials. High-molecular polymer is a kind of high-molecular material, has the adsorption effect, high polymer protection, can improve the advantages of slurry viscosity (Xu,2004 and Dehghanpour,2001). Some scholars carried out some study on the polymer material fluid loss agent in recent years, these study mainly focused on CMC, HEC, MHEC, CMHEC, starch and its derivatives(Zhang,2005 and Chevron,2009).About PAC (polyanionic cellulose) as drilling mud additives, a few of scholars carried out some relevant work. Plank (1992) applied PAC into ordinary freshwater drilling fluid and analyzed temperature stability of freshwater drilling fluid. Bennion (2000) applied PAC into drilling fluid and analyzed effect of polyanionic cellulose on strata inhibitory. Huang (2011) analyzed effect of PAC on properties of the high-density water-based drilling fluid. Mahto (2004) applied PAC into fresh water and salt-water drilling fluid and analyzed effect of PAC on rheological properties of the drilling fluid. Wang (2008) applied PAC into alkaline drilling fluid to study various performance of drilling fluid. PAC is a renewable resource and has good application prospect (Ankara, 2005). So it is very important to understand the effect of PAC on filtration process of drilling fluid.The test was conducted by changing the content of the PAC in drilling fluid. The object of this paper is to understand effect of polyanionic cellulose on filtration process of the low solid-phase drilling fluid."

Jan 1, 2017

By Joel Chipana, Roberto Laredo, Benjamin Cebrian

Ring blasting is a common production method in underground metal mines. As a drill and blast process, it presents particular features that do not correspond with bench blasting in open pit or underground mining.

Jan 1, 2017

By Milan Lj. Stamatovic

The hydrometallurgical recovery of zinc from recycled blast furnace dust from a steel plant (Smederevo Metallurgical Company, Yugoslavia) was investigated. The dust contained 22% Fe, 17% Zn and 0.2% Pb. X-Ray diffractometry showed that the main components were hematite and magnetite, in combination with zinc oxide. Individual particles were generally spherical and ranged in size from 10 to 150 microns; 63% were less than 33 microns in diameter. An effective hydrometallurgical approach proved to be by caustic leaching and electrowinning. Recovery of zinc in the form of zinc powder was over 90%; this material can be used for the cementation of impurities in the conventional hydrometallurgical process for zinc production.

Jan 1, 1994

By W. D. Mcmillan

Preliminary examination of the north-central Kansas clay deposits was made by the junior author during March 1943. He was accompanied by Norman Plummer, ceramist of the State Geological Survey of Kansas. Three areas Nacre selected for further investigation. Detailed field investigation by the Bureau, consisting of hand auger drilling, trenching, anti. test pitting to obtain representative samples of the clays was carried on from April to June 1943. Field .work was under the direction of Edgar B. Butte and Richard L. Schumacher, former Bureau of Mines engineers. The samples taken were analyzed at the Bureau of Mines laboratory at Rolla, Mo. Factual data obtained from the field investigation and laboratory work are set forth in this report.

Jan 1, 1948

By J. R. Sims

Gold assays from production blastholes in the Mercur Hill Pit were used to delineate known ore zones and to determine how well previous exploration drilling defined these zones. The most important factors causing inadequate ore zone definition were: 1) inappropriate location of drill holes relative to the ore zones, 2) presence of stopes from previous mining, 3) sampling and assaying errors, and 4) smoothing of the ore zone boundaries during ore reserve estimation. Infill drilling strategies were evaluated to determine the efficiency with which a given drill pattern defined the known ore zones. A drilling strategy was developed which improved ore zone delineation when compared to techniques which maintained uniform drill spacing.

Jan 1, 1992

By The Staff

FOR forty years cyanide men have been intensively engaged on the treatment of sulpho-telluride ores. So far as we know, the processes used today were-with the important exception of the concentration plus high-lime process at the Victor mill (1915)-in use, or had been tried, in the earl y years of the century. Roasting, bromocyanide, ordinary cyanide, table and vanner concentration, floating and treating the concentrate, roasting con-centrates prior to treatment, etc., all were used at Kalgoorlie in 1904 or earlier. Flotation, followed by shipment of the concentrate to the Golden Cycle mill, was the practice at the Vindicator mine, Cripple Creek, for some years prior to 1917. Similar practice was employed in the Portland Independence mill at Victor, Colorado, and was lacer superseded by the table concentration, high-lime cyanide treatment of rails of the older Portland Victor mill. During all this time, an immense amount of research was being clone on these ores by the staffs of numberless companies. Conclusions were drawn and mills built. But if the results of one per cent of this research were ever published in sufficient detail for intelligent use by others, the Lake Shore staff has been unable to discover them, or does not recall having clone so. Government laboratories-as for instance chose of the Mines Branch, Ottawa, in or about 1927-have touched upon certain methods in their publications, but they simply have not had the time to finish the job. The paper by W. E. Johnston, Tellurides-Problem or Alibi? (E. & M.]., Aug., 1933), aroused wide interest and comment. It published conclusions, some right and some wrong, and gave the evidence adduced by the author i:n support thereof. Conclusions published without supporting evidence are to most of us worse than no conclusions at all. We suggest chat, if even one-tenth of the operators had published full, detailed results of their laboratory work, ad vance in the treatment of sulpho-telluride ores would have been very much accelerated. Therefore, we venture to inflict upon the Institute a compendium of the results of laboratory work performed during the past few years at the Lake Shore mill. It is really a summary of the more interesting results to date, prepared by the mill staff for their own use and benefit. But we hope chat the discussion under any heading is so detailed chat it will be intelligible to anyone interested in that phase of the subject.

Jan 1, 1936