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Segregation roasting tests were carried out on Zaire cobalt oxide ores assaying about 2% Co and 3.5 to 6.5% Cu. The major parameters tested during the laboratory investigations were temperature, dosage and type of reducing agent, dosage and type of chloridizing agent, and particle size. Results showed that standard conditions suited to the segregation of copper ores, i.e. low temperature and low dosages of reducing and chloridizing agents, resulted in the segregation of copper only, while conditions suited to the segregation of lateritic nickel, i.e. higher temperature and increased dosages of reducing and chloridizing agents, led to a successful segregation of both copper and cobalt. Under the best conditions, 88% of the cobalt and 98% of the copper could be recovered in a concentrate assaying 32.5% Cu and 8.5% Co. Alternatives to process such a concentrate are briefly reviewed.

Jan 1, 1993

By S. T. Murray

The European industrial minerals industry and its markets are largely self-sufficient. The companies who are members of the Industrial Minerals Association (IMA-Europe) number around 150 contributing 5 billion Euros to the EU?s GDP and range in size from global publicly quoted corporations to small family owned private companies. Their means and capability to implement sustainable development vary considerably. However the leading companies provide an excellent set of best practices, which IMA as a trade association with recognised core competencies in the field of sustainable development is ideally placed to promulgate throughout its membership. As an active participant in the EU Voluntary Scheme for SDI reporting IMA is not only working to increase the level of response to the SDI questionnaire but is also developing with its members a new sustainable development charter which its members will voluntarily adopt as a guiding principle for their implementation of sustainable development This work will be a consultative process involving all IMA?s section members as well as other trade associations, NGOs and MEPs. Public awareness of the benefits of minerals and their contribution to sustainable development has been raised by IMA?s awareness campaign now being followed by a more targeted programme aimed at MEPs. Further work in the future will consider product stewardship and life-cycle analysis. IMA is already positioning itself with the help of its members to assimilate the minerals industry of the accession territories in the sustainable development process.

Jan 1, 2003

Spirals have become one of the most popular methods for treating fine coal. Unfortunately, spirals tend to produce an undesirably high specific gravity cut-point and often misplace significant amounts of coal and/or rock. In the present study, a process-engineering tool known as linear circuit analysis was used to identify problems with traditional spiral circuits and to suggest alternative configurations. These analyses indicate that a modified rougher-cleaner circuit incorporating a middlings recycle stream offers the best option for improving performance while maintaining a reasonable circulating load. In light of this finding, a full-scale test circuit was installed and evaluated at an existing preparation plant. Data obtained from the plant tests indicate that the new spiral circuit can simultaneously reduce cut-point and improve separation efficiency. Preliminary economic analyses show that the new circuit provides an attractive payback on the capital investment.

Jan 1, 1998

By Ronald L. Wiegel

In a mineral processing plant there are a number of routine decisions which are based at least in part on the plant's metallurgical performance. Among these are those related to: 1) equipment functioning properly 2) suitable operating conditions 3) reagents achieving desired results 4} determining operating response to changes in ore 5) defining circuits offering potential for improvement A step beyond the routine, are the periodic management evaluations of operating supervision and technical assistance, which are based largely on profit -a direct function of are availability, metallurgical performance and operating costs. The "yardstick", excuse me -"meterstick", by which performance is best measured is the plant metallurgical balance, which tells not only what was produced but how it was produced. Since this metallurgical balance is directly related to both plant profits and individual rewards, it is only reasonable to make that "meterstick" as precise as humanly possible.

Jan 1, 1978

By Christopher J. Vise

Although production operations at mines, representing the extraction and removal of the mined material, often appear to receive the greatest amount of attention, the emphasis given to auxiliary operations is continually increasing. This is due to the changing economic, social, and environmental climate in which modern mines must operate. Auxiliary operations can best be described as those activities that are not directly related to the extraction and removal of the mined material, but must receive proper attention if recovery is to take place in a safe, efficient, and socially responsible manner. In fact, certain mining auxiliary operations, such as strata control and ventilation, are considered to be of such importance that they warrant separate sections in this Handbook. Judging from a mine-personnel standpoint, it is not uncommon for a mine to hire the same number or more individuals responsible for auxiliary operations as the number assigned to production.

Jan 1, 2008

By H. Masuda

The lijima Zinc Refinery started operation in 1972, and has today an annual capacity of 200,000t-Zn. The hematite process was employed for the first time and the ideal of waste-free refinery has been pursued for 30 years. In recent years, however, only half of the hematite produced would be sold to the cement industry and hence a reduction of arsenic level has been necessary in order to sell the entire amount produced. The arsenic cementation process with zinc powder, developed through a long time laboratory research was found among some options as the best for the hematite process. The construction work started in 2000 and the facility was put into operation in 2001, As a result in the same year all hematite were sold to the cement industry. The outline of this project, present operations and technical issue are reported in this paper.

Jan 1, 2003

By C. B. Manula, R. L. Sanford, R. A. Rivell

A - Contains the coordinate pair information for deriving the co¬efficients of the 3rd degree polynomial which approximates the loading station equation. C(N) - Coefficients for third degree approximating polynomial. I - General DO LOOP variable. K - Position in BRANCH of next character. L - Format specification in DEFINE FILE statement. X - Uniform displacement for random uniform number. Y - Load increment At. AO-A3 - Coefficients of approximating polynomial for loading station equation. GR - Grade direction, or grade resistance. IQ - Counts quadruples of distance grade speed and end of route for determining total distance. IT - Intersection counter in XXXDEF. Il - Station number trip is leaving. Jl - Station number for trip destination. J2-J8 - Motor assignments and functions for given trip. KK - Location of starting grade and distance in DISTGR KK - Position of decimal point in real number. KZ - DO LOOP variable for motor assignment check. LL - Location of ending grade and distance in DISTGR. Ll - Position in IECB of station satisfied. L3 - Next available position for IECB sort. MM - Flag for printing the failure of sanding to overcome slippage. NN - Trip destination in MOTSER RR - Rolling Resistance. XK - Station level or type.

Jan 1, 1974

By J. G. Pippenger

Rio Tinto Coal Australia (RTCA) developed Meandu Mine in Queensland, Australia in 1983 to supply thermal coal to the adjacent newly constructed Tarong Power Station (TPS). In designing the mine, RTCA selected Meandu?s best economic reserves for a 25-year life based on station owner Tarong Energy Corporation?s (TEC?s) estimated life for TPS. That 25-year plan changed dramatically in the early 2000s when TEC approved life extensions to TPS?s four existing units plus construction of a fifth unit. After reviewing Meandu?s remaining reserves, RTCA decided the nearby Kunioon reserve offered the more economic option for maintaining deliveries beyond 2010. Those plans changed yet again in 2007 when TEC chose to purchase the Meandu Mine and nearby reserves rather than extend RTCA?s contract. TEC then selected Thiess Pty Ltd (Thiess) to continue operating Meandu until the new mine at Kunioon could be developed.

Jan 1, 2011

By E. Watkins, M. B. Daza

Although there have been great advances regarding the understanding of mine fires in underground mines in the last century, fires remain high risk incidents. During fire scenarios, many crucial decisions and actions can be made that greatly influence the outcomes of these scenarios. Underground worker decisions are mainly based on training and experience, which in some cases can be complemented with previous analysis of fire effects. In order to review the guidelines that should be taken into account for this kind of examination, a numerical analysis of effects produced by a shuttle car fire under five different ventilation conditions was carried out. The analysis provides some insightful recommendations for firefighting personnel such as time for direct attack and best attack position for first responders and fire brigade groups. Also, the most critical parameters for each scenario were determined. Finally, all results were systematically organized and a first approximation of a fire classification based on the tenability limits was provided for first responder and fire brigade groups. The methodology used in this study for the fire classification could allow for the most appropriate decisions by firefighting personnel increasing the probability to put fires out without compromising their health and safety. INTRODUCTION While there have been great advances regarding the causes of mine fires in underground mines in the last century “small fires have occurred and always will occur in underground mines” (Conti, Chasko, Wiehagen, & Lazzara, 2005). The response time and decisions made during an underground mine fire are critical elements that have direct influence on the event outcome. Mine fires can grow in size quickly causing catastrophic consequences, thus rapid and suitable response actions can result in the difference between an minor emergency situation and a disaster. Upon the confirmation of a fire, a decision must be made regarding whether to fight the fire or evacuate the mine. Even though all underground coal mines possess emergency response plans and firefighting personnel are highly trained, decisions can be complemented with previous numerical analyses. Such analyses could contribute with the knowledge of potential fire effects and consequently with fire preparedness in the mine. Preparedness in underground mines is an important element to reduce the probability of the negative consequences of a mine fire. The time elapsed between the detection of the fire and response in the early stage is a serious component since small fires can produce larger and more serious consequences. If a mine fire cannot be put out within the short time after discovery, the chance of getting the system back in balanced or the success of safely controlling and extinguishing a mine fire is reduced (Conti et al., 2005, Conti, Chasko, Wiehagen, & Lazzara, 2000, Trevits, Yuan, Teacoach, Valoski, & Urosek, 2009, Brake, 2013). As confirmed by Conti and others, if a mine fire cannot be controlled by direct firefighting methods the probability of extinguishing the fire, without sealing is greatly reduced (Conti et al., 2005). However, response actions such as direct extinguishment must be carried out without compromising the health and safety of the firefighting personnel (Kim, Lönnermark, & Ingason, 2010).

Jan 1, 2019

By D. L. Paulson

Electric furnace smelting of blister copper directly from copper precipitates (cement copper) was investigated by the Federal Bureau of Mines. Copper concentrations in five different lots of cement copper in the investigation ranged from 62.5 to 82.5 wt-pct. Laboratory-scale smelting tests were made in a 50-kva electric-arc furnace to establish the reductant and flux requirements. Best recoveries were realized by adding 60 pct of the carbon required to combine with the contained oxygen in the cement copper. Operating parameters established during the laboratory-scale smelting tests were used successfully in smelting 20 tons of cement copper during 12 pilot-scale tests in an 800-kva electric-arc furnace. Over 98 pct of the contained copper was recovered as blister-grade metal. The projected energy consumption for a commercial-size furnace was 380 kwhr per ton of cold charge.

Jan 1, 1978

By Paul C. McWilliams

This Bureau of Mines report analyzes data on the physical properties of quartzite rock from the Crescent mine, Coeur d?Alene mining district, Kellogg, Idaho, to demonstrate the use of multivariate techniques. After regression, factor, component, cluster, and discriminant analyses are discussed, these techniques are applied to the Crescent mine data. Three appendixes contain some of the required mathematical and statistical detail plus heuristic examples of three multivariate techniques --component, cluster, and discriminant analysis.

Jan 1, 1978

By C. Thomas Hillman

This Bureau of Mines report describes an investigation of factors influencing economic viability of a proposed system to mine and process manganese nodules. The system consists of hydraulic dredging and ammonia leach processing designed to recover three metals: nickel, copper, and cobalt. A ferromanganese recovery plant is a considered option. Annual capacity is 3 million dry metric tons (t) nodules. Aftertax rates of return (ROR's) of only 7.38 and 6.63 pct are predicted for three-and four-metal base scenarios, respectively. Sensitivity analyses indicate that variations in commodity prices, metal recoveries, and deposit grades produce similar incremental changes in ROR. Estimated cumulative effects of price variations are greatest. While three-metal operations generally yield higher predicted returns, potential increases in manganese price and process recovery could make four-metal operations most profitable. Maximum variations in both capital costs and three-metal operating costs result in ROR changes of about 25 pct. In contrast, four-metal ROR's exhibit variations to 70 pct. Even so only a best case analysis, utilizing favorable variations in all categories tested, generated ROR's approaching a level thought necessary to trigger company interest. Consequently, it is concluded that nodule mining will not take place in the foreseeable future without significant financial incentives.

Jan 1, 1985

By H. Masuda

The lijima Zinc Refinery started operation in 1972, and has today an annual capacity of 200, 000+-Zn. The hematite process was employed for the first time and the ideal of waste-free refinery has been pursued for 30 years. In recent years, however, only half of the hematite produced would be sold to the cement industry and hence a reduction of arsenic level has been necessary in order to sell the entire amount produced, The arsenic cementation process with zinc powder, developed through a long time laboratory research was found among some options as the best for the hematite process. The construction work started in 2000 and the facility was put into operation in 200 I. As a result in the same year all hematite were sold to the cement industry. The outline of this project, present operations and technical issue are reported in this paper.

Jan 1, 2003

By J. P. Cooney

Placer Dome is learning from experience in Latin America, Asia and Africa, as well as in North America, that contributing effectively to sustainable human progress in the areas of its operations presents unending challenges to think creatively, communicate effectively and remain culturally sensitive. People must be better off in terms of their economic circumstances, their social conditions and the quality of their natural environment not only during the life of the mines, but after mines close. Stakeholders, all those who are directly or indirectly affected by a mining project, should be able to participate in decisions which affect them. The development of sustainability strategies, the monitoring of sustainability performance and the implementation of sustainability programs are best done in partnerships with governments, communities, nongovernmental organizations and multilateral development institutions. Ultimately, the success, if not the survival of mining, will depend on our ability to get the sustainability equation correct.

Jan 1, 2000

By Luc Morin

What you don't know won't hurt you! This attitude can get you into trouble when considering your process! When trying to extract the most and the best possible performance from a mineral processing circuit this should be reworded to say: What you don't know about your process will hurt your profits! Today, with the popularity of joint ventures, custom milling contracts and process audits by specialists, not knowing is a formula for trouble! Good Sampling Systems are no longer considered a luxury' Not too long ago the practice of grab sampling was considered acceptable and became the norm. Today, it is rare to hear metallurgists say, "All I need is a trend not a good representative sample. so I'll just grab a sample every few hours." Buyers and sellers of quality products have found that grab sampling leads to poor partnerships'

Jan 1, 1999

An incremental-analysis-based stope design and cutoff grade calculation method was developed for an underground metal mine project. Traditional stope design methods are typically very time consuming and lack consistency and accuracy by manually drawing stope shapes. For quick reserve calculation and economic analysis, a new method named "3D incremental analysis based stope design" was created for mine-wide stope designs. The key idea of this method is to replace engineers' manual checking of each incremental ring with one calculation of all the rings, and to build the final stope shape with the maximum values. This process was realized through a 3D ring grid setup and proper naming conventions for rapid calculations. With this unique but practical method, multiple options for a mine design were completed within a short time before the final selection of optimal cutoff grade and best stope designs for the project.

Jan 1, 2012

Mineral processing plant operators are faced with the necessity to choose between many different possibilities for plant improvement. Only a few such possibilities, however, can be tested on the industrial site. Steady-state simulators make it possible to assess the effects of several different flowsheet modifications in a few days, thus helping the process engineer to make his choice implement the solution that seems the most appropriate and check it. The example described here is the crushing and grinding circuit of the Shila Gold Mine, jointly owned by CEDIMIN SA and BUENAVENTURA SA, in Peru. Several possible modifications for the purpose of increasing capacity have been simulated and the results assessed in terms of technical quality, investment costs and energy consumption. The best solution indicated by the USIM PAC simulator was implemented and gave a 20% increase in capacity with a pay-back time of two months.

Jan 1, 1993

By P. Meyers, F. DeSilva, L. Gottlieb

A number of tests looking at lead removal using ion exchange resins of various types from various aqueous streams have been undertaken. The tests focused on strong acid cation (SAC) and weak acid cation 0N AC) resins. It was found that the mechanism of lead removal is partly by lead filtration rather than solely by ion exchange in a large portion of the applications studied. This is not surprising since lead carbonate is essentially insoluble and almost all water supplies contain at least some carbonate alkalinity. Regeneration of lead from exhausted resins containing significant amounts of lead may not be practical in some cases because of the large chemical and waste volumes involved. Since lead, .·along with many other very insoluble metals, is often present as a suspended solid rather than in ionic form, ion exchange is probably not always the best technology for bulk lead removal.

Jan 1, 2000

By C. W. Owings

Available literature published or abstracted in 1953 and 1954 relating to dust prevention and suppression has been summarized and reviewed in this report, and un-published information also is included to outline current practice for those interested in dust control in and around mines, tunnels, and quarries. More and more companies are realizing the value of controlling dust by incorporating suitable methods and devices in the planning stage. In preparation and crushing plants preliminary tests have been made of the fine materials to determine the best type of dust-control equipment to use, and the details of the quantities of air, the number of sprays, the dust-allaying fluids, and the location of hoods or enclosures have been determined in advance. Such planning has paid for itself in more effective control. Similar planning in a tunnel resulted in healthful conditions and low dust concentrations.

Jan 1, 1956

By Gilbert M. Farrior

Tests of resistance to molten metals , to oxidation at elevated temperatures , and to various chemical reagents were made for a series of compositions in the TiB₂ - CrB₂ subsystem . In reaction with molten metals , there was no noticeable difference in reaction of the various compositions in the ( Ti , Cr ) B₂ series . The oxidation tests were ( 1 ) a rising - temperature test in which the specimen temperature was increased 4° per minute to 1,200 ° C and ( 2 ) a constanttemperature test in which the specimen temperature was held constant at 1,000 ° C. Compositions near Tio.6 Cro.4 B2 had the best oxidation resistance . Ti。.6 The chromium- rich alloys showed marked superiority to the titanium- rich alloys in resistance to corrosion by the chemical agents investigated . The chemical reagents used were sulfuric , nitric , and hydrochloric acids and sodium hydroxide of different concentrations .

Jan 1, 1964