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By T. A. Rickard

The function of a preposition is to show the relation of one thing to another; it is necessary therefore for the writer to select the preposition that indicates the particular relation, otherwise he will fail to express himself clearly. Is it against common sense' to suggest that a Government is justified, morally as well as constitutionally, in preventing the decay of an industry by insisting upon the amalgamation of the prosperous with the needy? All these seven prepositions are used correctly. With the first dredge introduced in Russia, of Werf Conrad, Haarlem, make, this method of alluvial dining became important. Here the prepositions "with", "in", and "of" are used wrongly. He means: "This method of a1lu;ial mining sprang into importance shortly after the first dredge, made at the Werf Conrad, Haarlem, was introduced into ;Russia." The statement itself ii not true, but for that I am not responsible. Once, while I was serving with him, we were frozen in out of sight of land in the Gulf of Pichili in the North of China. Admiral Fisher wrote thus. He has used nine prepositions in making this brief statement. The sequence of three prepositions "in out of" is particularly awkward.

Jan 1, 1931

By Arthur Grounds

Historical In the course of a paper which is necessarily limited in length, such as the present one, it is obviously impossible to describe in detail the history, development, and present position of coal preparation in Western Europe. Great Britain has been blessed with large deposits of excellent coal of nearly every type, ranging from the high-grade anthracites of South Wales, which are characterised by their very low ash and volatile con-tents, to the superb coking coals of South Wales and Durham -probably the finest in the world -with their low ash and sulphur contents, the latter constituent often well be-low l per cent. Gas coals abound in Lancashire and Yorkshire, while coals from the East Midlands, Northumberland, and Scotland are excellent for steam-raising and other industrial purposes. The excellent quality of these various coals has, in years gone by, ensured ready .sales abroad and it is not surprising, therefore; that methods of coal preparation were largely developed on the Continent in an endeavour to upgrade the inferior fuels found there, so that the prepared product could compete with British coals on the European market.

Jan 1, 1951

By A. J. Brown

This paper presents an economic evaluation of resin ion exchange and solvent extraction for the purification and concentration of uraniferous solutions derived from sulphuric acid leaching operations. Capital and operating costs are related to the uranium tenors of pregnant solutions. The conclusions drawn herein apply only to cases where resin and liquid ion exchange are technically feasible process alternatives. It is shown that solvent extraction is economically favoured for pregnant solutions at tenors greater than 0.90 gpl U3O8. Pregnant solutions with tenors below 0.35 gpl U3O8 are best treated by resin ion exchange. Between these concentrations, the economics are marginal and the favoured process is indistinguishable within the limits of accuracy of this study.

Jan 1, 1979

By F. Rosenblum, P. Spira

A laboratory test has been developed for assessing the patential hazard from self-heating of sulphides. The technique consists in measuring the rate of self-heating, from near ambient temperature, of a 1-kg sample in an insulated chamber controlled at standard atmospheric conditions. The rate of oxygen consumption is monitored simultaneously. The paper describes the apparatus and test procedure, and reports data on various ores and mill products. Tailings known to have caused problems underground when used as backfill have shown heating rates of over 3°C/h. A preliminary hazard rating guide for backfill based on the known behaviour of several sulphide materials is presented.

Jan 1, 1981

By M. S. Moholwa, J. D. Steenkamp, H. L. Rutto

Manganese ores are the major source of manganese for the production of manganese ferroalloys. There is a gap in the knowledge of the decrepitation behaviour of manganese ores, which presents a problem in the operation of smelters. Decrepitation, which is the breakage of the ore particles upon heating, is an important quality parameter for these ores. The purpose of this investigation was to determine the extent to which South African manganese ores decrepitate during preheating in a rotary kiln. The effects of temperature, rotational speed, and particle size decrepitation were investigated. Manganese ores were heated in a laboratory-scale rotary kiln at temperatures of 600, 800, and 1000°C, and rotational speeds of 3, 6, and 12 r/min. The size ranges were +6-20, +20-40, and +40-75 mm and the residence time was constant at 30 minutes. The decrepitation index (DI) is quantified as the ratio of the mass of <6 mm particles after pre-heating to the total mass of the sample. It was found that the DIs for all ores used were proportional to the temperature and the rotational speed and inversely proportional to the particle size range with temperature being the most important parameter. Ore A was the most susceptible to decrepitation followed by ore C and ore B; this was mainly to the decomposition of kutnohorite, the content of which was the highest in ore A and the lowest in ore B.

Nov 30, 2022

By D Pienaar, B McFadzean, C T. O’Connor

Collector and frother molecules in sulfide mineral flotation are thought to have separate roles in the flotation process, where the collector selectively hydrophobizes the mineral surface and the frother adsorbs onto the bubble surface, inhibiting bubble coalescence. Molecular interactions have been observed between these molecules which allow them to co-adsorb at each of the respective interfaces, improving pulp phase recovery. This study investigated the molecular interactions between sodium diethyl dithiophosphate (SDEDTP) and hexanol, and the mechanism by which these interactions improve the recovery of galena. In this study each of the respective interfaces were investigated for the adsorption of SDEDTP. The adsorption of SDEDTP on galena was measured by UV-Vis spectrophotometry and isothermal titration calorimetry. At the air-water interface foam stability and pulp bubble coalescence was used to quantitatively discern if there are interactions between SDEDTP and hexanol. Microflotation and induction time experiments were performed to determine the effect of SDEDTP, hexanol and their mixtures on mineral recovery and bubble-particle attachment. The results of all these tests were collated to determine if SDEDTP-hexanol mixtures synergistically improve sulfide mineral recovery. It was found that SDEDTP reduced bubble coalescence in the pulp demonstrating activity at the airwater interface. Together SDEDTP and hexanol synergistically enhanced foam stability. This indicated that there are attractive molecular interactions between these reagents. Even though DTP did not adsorb onto galena, DTP-frother mixtures synergistically improved the recovery and attachment probability of this mineral. Adsorption studies with aeration showed that DTP in the presence of a frother transfers from the air-water interface to the galena mineral-water interface during bubble-particle collision. It was proposed that the transfer of hexanol through the thin film enhanced the kinetics of film thinning between the bubble and the particle by destabilising the thin film thus improving pulp phase mineral recovery.

Aug 24, 2022

By Larry G. Twidwell

The removal of dissolved arsenic from mine waste waters utilizing a lime/phosphate precipitation technique has been studied on a laboratory scale at Montana Tech of The University of Montana and on a pilot scale at MSE Technology Applications as a wastewater treatment process potentially capable of removing dissolved arsenic to <50 µg/L. Arsenic bearing lime and lime/phosphate slurries were subjected to laboratory extended-time air-sparged aging for over four years. The lime slurries released their arsenic back into solution in a relatively short period of time, whereas the lime/phosphate slurries showed limited release of arsenic. The developed process has been pilot scale tested by MSE-TA for the EPA Mine Waste Technology Program on three waters, ASARCO smelter blowdown water, ASARCO thickener overflow water, and Mineral Hill Mine groundwater. The laboratory study results will be presented and discussed in this presentation. The pilot scale results will be presented and discussed in a companion presentation. Stability, Aging, Apatite, Johnbaumite

Jan 1, 2005

By Juan Estrada, Mirtha Frómeta, Rubén Alcalá, Emilio Montejo, José Castellanos, Juan Berto, María Rivas

"The oxidized nickel ores from San Felipe deposit are composed mainly Smectites which gives to the pulps very unfavorable rheological .properties (cinematic viscosity and high shearing strength) for transportation processes (pumping), very low settling velocities and very low thickened pulps. These properties do not allow the preparation of high % solids, which affects the economic efficiency if a high pressure acid leach (HPAL) process is used. Pulps of close to 30% solids have very high BYS making pumping impossible. CIPIMM developed three technologies to solve these problems and to substantially increase the % solids in the pulps to be leached without a thickening step. These technologies are: • CIPIMM 2. At Preparation of pulps using additives. This method is based on the effect of some additives (inorganic salts) to improve the pulp’s properties. The use of this method allows increasing the % solids in the pulp up to 40% with good rheological properties • CIPIMM 2B. Preparation of pulps by thermal treatment of the ore previous to the preparation of the pulps. This method is based on the thermal destruction of the clays structure. Its use allows to obtain pulps with 50 - 60 % solids with excellent rheological characteristics. As a collateral effect, the Ni and Co grades increases by 10 - 15%. • CIPIMM 2C. Pulp preparation by chemical treatment. This method is based on the chemical transformation of clays, to obtain without thickening, pulps with 43- 45% solids and excellent rheological properties. The use of one of the three technologies depends on the chemical and mineralogical composition of the ores and the results of technical-economical evaluations to determine which one is the best alternative before running higher scale tests."

Jan 1, 2014

By G. van Eck, H. Smit, L. Meyer

The Cook Islands (CI) possesses within its Exclusive Economic Zone (EEZ) a massive field of polymetallic nodules representing one of the world’s largest undeveloped cobalt deposits, along with large quantities of other metals critical to achieving global energy transition targets. In February of 2022 the Seabed Minerals Authority (SBMA) of the CI granted Moana Minerals a license to conduct our nodule exploration program. This paper describes how Moana Minerals chose to approach conducting exploration activities, one of the greatest challenges to Deep Sea Mining (DSM) development and the securing of the social license to advance to eventual mining of the resources, in an unconventional manner. The remote location of the project poses logistical challenges in mobilizing to and operating in the region and is a significant cost driver. Historically, exploration campaigns mobilized large vessels from mainland Europe, the Americas, and Asia as this model works well when contemplating long duration and widely temporally spaced campaigns without the need to revisit. Moana Minerals, when considering these challenges determined a multi-year deep sea mining (DSM) exploration program conducted in such a remote location can be better optimized by the deployment of a smaller yet highly capable “exploration optimized” vessel that is dedicated to the task and is based full time in the Cook Islands. INTRODUCTION The paper describes the challenges of exploration in remote regions including the South Pacific, and how an unconventional consideration of the problem led to the solution. Completion of an Environmental and Social Impact Assessment begins with a detailed environmental scoping study, resource update sampling requirements, and engineering data and sample requirements, which identifies the exploration goals of the project and technology needed to accomplish those goals. The method walks the reader through vessel and technology selection, discusses the challenges of equipment selection considering size and capability, describes the final arrangement, and provides results from the initial exploration campaigns. We followed the project from conception through the shipyard conversion, mobilization, and initial operations in the Cook Islands. The result shows how a smaller vessel with limited budget makes a large impact on the exploration capabilities in the region while building public trust. The Anuanua Moana is the first dedicated deep sea minerals exploration vessel modified with a suite of technologies that allow it to compete technically with existing ships but operate locally in the smaller ports of the South Pacific. The unique combination of size and technical capability gives the Anuanua Moana advantages over other vessels. This paper shows the importance of the Anuanua Moana in the development of offshore exploration strategies in the emerging deep sea minerals space.

Feb 22, 2026

By H. J. van Antwerpen

AngloGold Ashanti operates the world`s deepest mine, Mponeng gold mine, in South Africa. A vast refrigeration and ventilation system provides acceptable working conditions 3800m below surface at 60°C rock temperature. In such a system, optimisation and assessment of modifications becomes very difficult. With that in mind, a research project was launched to determine whether recently developed system simulation technology can be applied to a mine as vast and complex as Mponeng. Using the techniques and methods as implemented in FLOWNEX software, it was indeed proven to be possible to do a mine-wide combined simulation of compressed air flow, ventilation air psychrometry and refrigeration water systems. Interactions between the various streams included heat transfer, pressure drop, evaporation and condensation. The simulation model was used in a parametric study to test various water flow and temperature operating points for the refrigeration system. It was found that, given current limitations, the mine refrigeration system is running fairly close to optimal but with some opportunities for improvement. The simulation model also provided useful insight for future changes or extensions to the system.

Feb 23, 2014

By W. I. Nelson

This paper which describes the milling practice of the Engels Copper Mining Co., is one of a series on milling methods being prepared for and published by the United States Bureau of Mines. ACKNOWLEDGMENTS Acknowledgment is made of the assistance rendered by J. Casagrande, mill foreman of the Engels concentrator, in collecting much of the data presented in this paper.

Jan 1, 1932

By Edo Engel

Hot Blast Stove Technology has been developed to such an extent that low cost hot metal production for over 30 years without major repairs has become achievable, making the decision for a campaign length between 5 to over 30 years a design choice for the plant owner/operator. Some of the earlier examples of designs capable of such long campaign lengths are currently close to the 50th year of their running campaign. These examples are found especially in Europe and North America. Along the duration of these campaigns, repairs to subsystems such as burners, hot blast outlets etc. may be required. Depending on a plant’s up and down stream production capacities, the repairs may have to take place in the shortest possible time frame to minimize production loss. This article discusses an approach for intermediate repairs, executed while keeping the majority of the system at operating temperature.

Oct 30, 2017

By David Harrison

Exxon Minerals Company uses geostatistical techniques for ore resource evaluation of its mineral projects. These techniques provide the most reliable estimates of recoverable tonnage and grade and uniform and realistic confidence limits. A schema has been developed which categorizes the company&apos;s successive evaluation phases. Clear separation is intended between geostatistical estimates and other factors in project evaluation such as mining, metallurgy, and economics. Company management seeks consistent and reliable estimates for investment decision-making and to meet growing demands for disclosure of mineral assets.

Jan 1, 1983

By P. Quinn

"The Venturi-aerated flotation column (VAC) is based on a reactor and separator design for a new generation of flotation machines. The reactor is a Venturi tube, where the air/slurry contact takes place with intensive aeration for efficient particle collection. The separator is a column of 1-3 m length that provides quiescent hydrodynamic conditions for effective separation of bubble-particle aggregates from the remaining slurry.Aeration in the Venturi tube occurs via two mechanisms: air dispersion and nucleation (cavitation). By forcing air through a restricted passage with a fast flowing slurry stream, air is dispersed into fine bubbles. Bubble formation due to cavitation occurs on the surface of particles in the low-pressure section of the Venturi, from dissolved air contained in the liquid.Size-by-size recovery and flotation rate constants were determined for a small-scale laboratory Venturi-aerated flotation column. The results were compared to those obtained in a laboratory 2.2 L Denver cell. It is shown that the Venturi-aerated flotation column has slightly slower flotation kinetics to the Denver cell, but with much higher flotation selectivity. A portable Venturi-aerated flotation column can effectively be used to investigate process or equipment problems in operating plants.INTRODUCTIONFlotation processes can generally be divided into two sub-processes: 1) selective collection of hydrophobic particles by air bubbles and 2) separation of bubble-particle aggregates from hydrophilic particles that remain in the pulp. The methods of aeration, or bubble generation, control the mechanism of particle collection by either collision with, and subsequent attachment to bubbles, or by in situ bubble formation on the surfaces of hydrophobic particles. A flotation device should provide optimal aeration conditions for efficient particle collection and a suitable hydrodynamic environment for effective removal of bubble-particle aggregates from the remaining pulp."

Jan 1, 2002

By John C. Machisak

INJURY experience and employment data for the nonmetal mining industry in the United States are presented for the calendar year 1958. Statistical tables 6 to 12 give detailed information on injuries and employment at nonmetal mines. Data for nonmetal mines are presented separately from those for nonmetal mills, tables 23 29. The Bureau is authorized to send questionnaires to the nonmetal industry for their voluntary submission on of injury and employment experience at their operations. As this information contributes to the promotion of safety in the nonmetal mining industry, every effort has been made to make these questionnaires as complete as possible.

Jan 1, 1962

By James S. Goff, Stephen J. Navin, Wesley W. Moulton

The White River Shale Oil Corporation (WRSOC), as agent for Phillips Petroleum Company, Sohio Shale Oil Company, and Sun Shale Oil Company, is developing a prototype oil shale facility on Federal Lease Tracts Ua and Ub, located in northeastern Utah and known as the White River Shale Project (WRSP). The Ralph M. Parsons Company (Parsons) has been retained as the design engineer/constructor for the project. This paper covers the successful pregrouting of the Bird&apos;s Nest Aquifer in conjunction with the sinking of a 9.2-m (30-ft)-diameter shaft and driving of a 3.89-m by 5.64-m (18.5-ft by 12.75-ft) decline. The Bird&apos;s Nest Aquifer derives its name from the ellipsidal solution cavities caused by leaching of random-size nacholite nodules. The sodium bicarbonate nodules occur as persistent bands within a matrix of siltstone and marlstone. The team, made up of the owner, engineer/contractor, and subcontractor successfully grouted the shaft down to an inflow of less than 0.06 lps (1 gmp) and the decline down to less than 0.12 lps (2 gpm) by injecting a total of 213.190 kg (470,000 lb) of Celtite Terraseal, 113,400 kg (250,000 lb) of limestone dust, and 41,730 kg (92,000 lb) of cement into the formation.

Jan 1, 1985

By Herry Poernomo, Agus Prasetya, Iga Trisnawati, Himawan Tri Bayu Murti Petrus, Gyan Prameswara, Panut Mulyono

We studied yttrium extraction from untreated zircon sand processing waste tailings. Xenotime mineral as the rare earth element source with an abundance of yttrium (REY) was detected in sufficient grade for extraction. As much as 9.03% yttrium exists in zircon tailings (analysed by X-ray fluorescence spectrometry). The presence of yttrium was confirmed by X-ray diffractometry in xenotime minerals, which are yttrium carriers (Y-PO4). The purpose of this research was to determine the effect of leaching conditions on yttrium recovery from zircon sand after alkaline fusion treatment. Alkaline fusion was chosen to decompose phosphate into hydroxide in the xenotimemineral,which will reduce further required hydrometallurgical processing.Alkaline fusionwas carried out for 3 h at 450 °C, with a ratio of sodium hydroxide to zircon tailings sand of ~ 1:1. The alkaline fusion product was leached with water, followed by hydrochloric acid treatment to leach the yttrium. Yttrium recovery reached 87% under optimum conditions (60 °C, 1MHCl, and solid-to-liquid ratio = 1/10 for 7.5 min). A suitable model for yttrium dissolution with hydrochloric acid was diffusion through a solid particle ash layer. The calculated activation energy (EA) for this model was 20.21 kJ/mol.

May 26, 2020

By R. T. MacMillan

Many bench-scale tests and studies have been conducted in developing and testing a chloride-volatilization procedure Ear treating low-grade manganese ore from the Maple Mountain-Hovey Mountain deposit of Aroostook County, Maine. The ore, averaging 10 to 12 percent Mn, contains manganese in several forms and is resistant to concentration or extraction by usual physical and chemical procedures. Over 90 percent of the manganese, content of the ore has been recovered using a chloridizing roast in which the ore was heated at 950°-9b0&apos; C. in a circulating stream of hydrochloric acid gas. Chlorides of manganese and iron were volatilized and swept to a fume collector, where they were condensed and separated from the [as] stream. Operation of a small, 1-pound-per-hour shaft Furnace produced enough chlorides for studying other factors in an integrated process such as: (1) Conversion of the chlorides to oxides; (2) recovery of HC1 gas of suitable concentration Ear recycling to the chloridizer; and (3) control of the Mn-Fe ratio in the oxide product to produce a suitable feed for ferromanganese production.

Jan 1, 1956

By Negin Khalili-Motlagh-Kasmaei, Paul O'Leary, Christopher J. Rothsiedl, Dimitar Ninesvski, Alexander Zöhrer, Vincent Winter

This paper presents the implementation of a digital twin for the vibro-replacement ground improvement process, as part of a digital construction site. The goal is to implement an evidence-based quality assurance for each produced element (column or point). The system uses a combination of planning data and real-time machine data collected automatically from construction equipment. In addition to the quality assurance, feedback is provided in a number of areas, e.g., condition monitoring of the equipment. The digital twin builds upon the real-time sensor and machine data, fused with metadata, to implement a digital model for the process. A hierarchical data evaluation, using rule-based Key Performance Indicators (KPIs), permits viewing of the spatial variation of data over the construction site. This permits the modelling of systematic variations in subsurface properties across the site, enabling the detection of anomalous individual elements, the diagnosis of their cause and the prediction of properties as construction proceeds over the site. All time-series data and KPIs are represented by standard classes of objects, leading to a generic coding of the data analysis; this minimizes the effort required to add additional sites and/or new KPIs. Examples are presented for a number of sites, where the system was used to identify anomalous columns.

May 1, 2022

By Thang V. Nguyen, Lisheng Shao, Gary E. Taylor

"The Community Memorial Hospital of Ventura, California, proposed to build a new state-of-the-art Cancer Treatment Center with radiation shielding walls and roof. The loose silty soils at the site had the potential to liquefy during an earthquake, which would result in significant settlement under the heavy footing loads. Treatment options included various deep foundation alternatives, as well as several ground improvement methods. The choice of wet soil mixing minimized the disturbance to the adjacent hospital during construction and potential settlement. Wet soil mixing allowed the structure to be supported on a raft foundation, meeting the stringent building total and differential settlement criteria. The authors also performed unit cell 3-D finite element analyses to evaluate the behavior of the wet soil mixing system in seismic loading conditions. This paper highlights the ground improvement design, construction, QA/QC, and the research related to evaluating the effectiveness of soil mixing for liquefaction mitigation.INTRODUCTIONThe Ventura Community Memorial Hospital proposed the construction of a new Cancer Treatment Center to replace the existing structure, which was built in 1901. The hospital complex is located in a wellestablished residential neighborhood. The soil conditions at the site of the proposed structure required ground modification to support the very heavy radiation treatment section of the building and limit settlement. Originally, 90-foot-long precast piles were considered for foundation support. Based on supplemental Cone Penetration Tests (CPTs) performed, the deepest CPT did not encounter competent pile bearing strata at a depth exceeding 30.5 m (100 ft). This could result in failure of the piles under long-term conditions, especially if hydro-consolidation occurs. The more realistic pile penetration depth would have been 36.6 to 45.7 m (120 to 150 ft). In addition, the excessive noise in association with pile driving would have been unacceptable to the community, patients, and staff of the hospital, so an alternative ground improvement solution was required.The specialty geotechnical contractor recommended wet soil mixing, an economical solution of creating a soil-cement product known as soilcrete that would significantly reduce the construction related noise and provide a more complete deep foundation for the structure.SOIL CONDITIONS AND SETTLEMENT CONCERNSThe subsurface soils were interbedded (Fig. 1) consisting of loose to medium dense silty sands, and soft to medium stiff silty clays to a depth of 30.5 m (100 ft). Groundwater was encountered at depths of 9.1 m (30 ft) and historical high groundwater was at 8.5 m (28 ft) below the ground surface."

Jan 1, 2015