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By P. Hickey, J. Spenceley, T. J. DeMull

Development of the Batu Hijau Project was successfully completed in the fourth quarter of 1999 with the final handover and start-up of ore processing facilities. The development project had started more than three years earlier, in August 1996, when the Owner, PT. Newmont Nusa Tenggara (PTNNT), awarded an EPC contract to Fluor Daniel (FD) for design and construction of the project including: copper concentrator, port, power plant, town site, and infrastructure. PTNNT managed the development of the mine and procurement of mine equipment with its own forces. Bringing the Batu Hijau copper deposit into production was the largest mining project ever undertaken. Development of Batu Hijau was a complex project involving the work of tens of thousands of people in all parts of the world to complete engineering, manufacture and deliver equipment, supply materials, and build the plant. The ore deposit is located on the tropical island of Sumbawa in a remote and undeveloped section of Indonesia. The location and environment presented challenges for all phases and aspects of the project. To meet the challenges, the project team combined good planning and teamwork to best utilize the resources available. This approach assured continuity of personnel through construction to operations and minimized cost, resulting in completion of the project ahead of schedule and under budget.

Jan 1, 2001

By Sang Han Son

The vapor pressures of FeCL2 and ZnCL2 in the FeCL2?ZnCL2 system were measured by the transpiration method at 873K and 9I7K, The vapor pressure data were interpreted to indicate the formation of complex ions in the FeCL2?ZnCL2 melts, It is presumed that the complex molecule FeZnCl4 as well as FeCL2 and ZnCL2 exists in the vapors in equilibrium with molten FeCL2-ZnCL2 mixtures, The activities in the FeCL2-ZnCL2 system are shown a negative deviation from Raoult's law. These results suggest the formation of complex ions such as ZnCL14 in molten FeCI2?ZnCL2 mixtures.

Jan 1, 2003

By William A. Faust

At Gold Fields' Chimney Creek Mine, major reviews of the reclamation and closure plans are done concurrently with the annual mine planning required for budget preparation. This review includes identifying and scheduling reclamation work that can be done within the next few years and development of associated costs. Longer term mine, leach pad and waste dump development are examined to take advantage of any design changes that can reduce ongoing reclamation or closure requirements and reduce costs. The success and cost effectiveness of past efforts are continually evaluated to determine the best methods for reclamation.

Jan 1, 1992

Today’s world relies upon advanced green technologies that are made of critical elements with unique properties. Examples include rare earth elements (REEs) that are critical in the manufacturing of wind turbines and electric/hybrid vehicle batteries, key components of a greener future that face supply uncertainty and near zero recycling. To tackle their supply challenges, activities have begun for urban mining from waste electrical and electronic equipment (WEEE) that contain considerable amount of REEs, but their current level of recycling is less than 1%. Current recycling practices use either pyrometallurgy, which is energy intensive, or hydrometallurgy that utilizes large volumes of acids and solvents and generates large volumes of hazardous waste. In this study, we developed a novel and sustainable process to recycle REEs from WEEE, NiMH batteries in particular. The developed process relies on supercritical fluid extraction (SCFE) utilizing CO2 as the solvent, which is abundant, safe, cost effective, and inert. The effect of seven operating parameters, namely temperature, pressure, residence time, sample to chelating agent ratio, agitation rate, complex formulation, and methanol addition on REE extraction efficiency was investigated, and optimum operating conditions were determined. This work is the first to utilize a very efficient and safe process that runs at low temperature to extract metals from postconsumer products with minimum hazardous waste generation, while offering about 90% leaching efficiency for REEs. We expect our process to find widespread applicability in urban mining of REEs using green chemistry.

By Y. F. Bulgakov, Y. V. Melnikova, V. S. Zakharov

A new technology of atmosphere in inertization of fire section with the help of gazeous nitrogen is presented in the report. This technology is based on membrane air subdivision into two streams, concentrated with nitrogen (up to 99%) and with oxygen correspondently with subsequent giving them into the place of fire. This technology belongs to environmentally friendly ones and it has a great number of technical, mobile and economic advantages comparing with the rest of well-known methods of fire extinguishing. This technology application in Ukrainian coal mines allowed to reduce the member of isolated places of fire at the expense of their extinguishing efficiency.

Jan 1, 2003

By W. Rodríguez

Ante los recientes estudios sobre la relación del impacto ambiental con las operaciones minero metalúrgicas, se ejecutaron acciones legales que contrarresten los efectos detrimentales de los efluentes líquidos, gaseosos y sólidos de las plantas metalúrgicas. En este sentido, el presente texto plantea el uso intensivo de las aguas del drenaje de la mina Cerro de Pasco a través de la planta de extración por solventes y electrodeposición en la recuperación de cobre cadótico, con la finalidad de reducir los costos de producción y la contaminación ambiental. Así también se plantea el reemplazo del proceso de neutralización clásica con óxido de calcio por el método de la bioxidación, neutralización y precipitación de los elementos contaminantes en los efluentes mineros metalúrgicos de la cuenca de Yanamate, transformando el desarrollo de la minera Cerro de Pasco.

Apr 1, 1991

By Anthony P. Makuch

Dynatec Corporation is an integrated mining services company, providing mine development, operations management, engineering, drilling and metallurgical services to the North American mining industry. Dynatec was the contract operator of the Ken Snyder Mine in Midas, Nevada from start of production in January 1999 to September 2001. This paper summarizes Dynatec?s experience and approach to the use of longhole stoping methods for mining to widths of 1.3 to 2 metres in a steeply dipping narrow vein orebody.

Oct 1, 2001

By Nigel Pearson, Malcolm J. McPherson

In the Grasberg Mine, a series of orepasses of diameter 2 to 4m are being constructed, each one to carry as much as 10,000 tlhour of copper- and gold-bearing ore through single stage vertical drops of over 500m. At the base of each orepass, the fragmented rock falls into an orebin of diameter 1 Om and 100m deep. Long before the planned tonnages were reached on the early orepasses, a problem arose that was both serious and intriguing. Pressurization of air in the orebins caused by the falling rock reached such levels that when the feed to the top of an orpass was interrupted, a massive surge of air ascended rapidly and produced a dangerous backblast accompanied by dust; grit and rock fragments from the top of the orepass. Backblasts lasted for about one minute and were not only hazardous to the health and safety of personnel but also required time-consuming clean-up operations. The paper describes the aerodynamic analyses that were con- ducted in order to understand fully the mechanisms involved in the phenomenum, and the development of a procedure that al- lows the effects of falling material to be incorporated into existing ventilation network software.

Jan 1, 1997

By Farhang Hedjazi

Anglo Asian Mining have recently installed an industrial-scale UF/RO plant to treat process liquors from the integrated heap leach/agitation leach/ resin-in-pulp gold ore treatment facilities at their Gedabek gold-copper mine in Azerbaijan. The UF/RO plant is designed to treat 60 m3/h of leach solution to produce discharge quality water. The RO concentrate, which contains elevated concentrations of copper, silver and cyanide, is sent to the company’s SART plant for the recovery of the metal values as a precipitated sulphide concentrate and the cyanide, which is recycled to leaching. The new water treatment plant improves the sustainability of the operations at Gedabek by enabling replacement of fresh water input with RO permeate and safe discharge of permeate to the environment, during periods of excess water balance. The paper includes pilot plant data and early results from the full-scale plant.

By Robert M. Valentine, Randall L. Lentell

Interpretive geotechnical investigations were performed for the construction of approximately 15,250 m (50,000 ft) of wastewater interceptor tunnels in Austin, Texas. Subsurface materials consist of claystone (or clay shale), siltstone, altered volcanic tuffs, chalk and limestone. Special conditions include multiple crossings of Onion Creek with cover ranging from about 1/2 to 3 m (2 to 10 ft.), and the potential for mixed-face conditions consisting of water-bearing gravels overlying clay shale or siltstone. The methods and results of the geotechnical investigations are discussed and the inferred construction conditions are compared to those encountered during tunneling. A suggested format is presented for interpretive geotechnical reports for underground construction projects.

Jan 1, 1985

By Arif Emre Dursun, Ali Aras, Hakan Özşen

Specific energy (SE) is defined as the amount of work required to cut a unit volume of rock and is used to estimate the performance of excavation machines. Generally, the SE value is produced from full-scale or small-scale rock cutting tests. However, these tests require expensive equipment and experienced personnel, and the testing procedure is time consuming and impractical. Therefore, for estimation of SE, this study aimed to find a solution to estimate SE using rock mechanics test results and Bond work index values (BWi), which can be produced in a more practical, less time-consuming manner and with inexpensive test equipment. Small-scale rock cutting, rock mechanics and Bond work index tests were carried out on seven rock samples, which can be grouped into two different type of rocks: marble and travertine. In addition, the instantaneous cutting rates (ICR) of a selected roadheader were calculated using SE values. Rock mechanics tests performed in this study were uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), ultrasonic velocity (Vp), Schmidt rebound hardness (RL), corrected point load index (Is(50)) and density (ρ). The simple regression method was used to estimate SE from rock properties and BWi. As a result of this simple regression, a significant and highest correlation was found between SE vs. UCS and Is(50). A good correlation was found between SE vs. BTS, RL and BWi values. A moderate correlation was found between SE vs. Vp and ρ.

Jul 28, 2021

The preamble to the mining Act sets out that such Act is to provide for the encouragement and regulation of mining within the State of Queensland. This paper will attempt to follow the legislative path of such aim and in particular to show what part Mining Wardens play in the administration of the Mining Act.The Mining Act empowers the Governor in Council to constitute Mining Districts and Mining Fields and to appoint any duly qualified officer of the Public Service of Queensland to be a Warden or a Mining Registrar. As a matter of practice Stipendiary Magistrates who hold office in the major centre within a Mining District are appointed Wardens and Clerks of the Court are appointed Mining Registrars. In some districts where there is no Stipendiary Magistrate the Clerk of the Court is appointed an Acting Warden with all the powers of a Warden. Every Warden so appointed is a Warden for the whole State.To achieve impartiality Section 74 of the Mining Act provides that a Warden shall not hold or be entitled (directly or indirectly) to the benefits of any share or interest in a mining tenement or mining venture and provides a penalty of $1000 or imprisonment for six months or both, for contravention of such section.

Jan 1, 1986

By E. G. Kelly, D. E. Walsh

The behavior of gold particles on a spiral was studied using radioactive gold tracers. The method allowed the effects of particle size, particle shape, pulp density, feed rate and splitter settings to be studied. Although the method has been successfully applied to other gravity concentrators, it was found that reliable results were more difficult to obtain on the spiral. However, these preliminary results show that, with suitable precautions, the technique is capable of providing valuable information, unobtainable from conventional studies, that could be used to better optimize spiral performance.

Jan 1, 1993

By John P. Gooch

The Bureau of Mines wrote a computer program which calculates the saturation curves and condensation characteristics of gaseous mixtures consisting of binary organic vapor and air. The program employs an algorithm which assumes an equilibrium mechanism for condensation, and the degree of fractionation obtained is predicted on the basis of relative volatility. The program incorporates a feature which allows the user to examine the fractionation resulting from condensation as a function of the size of the temperature increments over which condensation is assumed to occur. If a single. temperature interval between the dewpoint of the mixture and the outlet temperature of the condenser is assumed for the calculation, the results obtained will be those resulting from a single equilibrium condensation. If the condensation is assumed to occur over a number of temperature increments, the results obtained will approach those predicted by the Rayleigh equation as the magnitude of the temperature increments approaches zero. The results from calculations performed on vapor mixtures from organic heavy liquid solutions used in beneficiating potash and brucite ores are presented. The liquids are solutions of dibromomethane in trichloroethylene or perchloroethylene. The results show the degree of liquid recovery which is possible by cooling mixtures of organic vapor in air. Compositions of the vapor range from 10 to 95 percent air, and assumed condenser exit temperatures range from 110° to 50° F.

Jan 1, 1971

By R J. Goldie

The Monty Copper Gold Deposit is an ultra-high grade mine in Sandfire Resource’s Doolgunna region which was completely drilled out and developed within two years of commencing mine development. During this period, a total of 986 grade control diamond drill holes were completed, assayed, and validated, 15 levels developed, and 3136 faces mapped. The aggressive schedule meant a high flow of geological data was produced, validated, and incorporated into regular geological model updates. To process this data at a rate which allowed for timely use, more robust data processing methodologies needed to be generated. A new validation system was implemented which required two levels of validation being applied to any diamond drilling update. Step one was the validation of initial physical data including survey pick-ups and logging. This was done prior to new drill data being added to the geological model. Step two was the validation of assay data which was required prior to resource estimation. The implementation of Seequent’s Leapfrog Geo modelling software also allowed for a more seamless and efficient modelling workflow. The use of the Leapfrog Geo vein systems allowed for more rapid generation of geological models which then afforded more time for stringent assessment of the mineralisation system. An example of this was the introduction of cross-shift peer reviews in which opposing rosters of geologists would rigorously evaluate the previous rosters work prior to reporting. This additional level of validation resulted in more robust geological models and the identification of new ore trends. This presentation will detail the evolution of the Monty Geological model from a simple tabular indicated resource into a complex highly refined measured resource. Themes will include how the model was produced using workflows developed and optimised to meet key deliverables.

Mar 22, 2022

By Douglas W. Fuerstenau

This report presents the results of an investigation of comminution in tumbling mills. Five different topics involved with ball mill and rod mill grinding kinetics were studied and the results analyzed in terms of phenomenological size reduction and transport models. Continuous rod mill grinding was found to be characterized by high Peclet numbers which permit simulation to be carried out by several methods. The dry batch ball mill grinding of mineral mixtures showed that the breakage rates of the components were composition-dependent but time-independent and were normalizable with specific energy. Locked-cycle tests on mineral mixtures showed that a grinding circuit may take a long time to attain steady-state, during which time the composition of the mill holdings, and hence the breakage rates of the components, continuously changed. This study revealed that under plant conditions, grinding circuits can be in transience perpetually. The transport of mineral mixtures through drums was found to exhibit complex size and/or density-dependent segregation. However, the grinding media in a ball mill can eliminate such segregation, thereby simplifying the modeling of the continuous grinding of complex feeds. Wet batch rod mill grinding on single minerals divulged that the normalizability of breakage kinetics is valid for slurries of constant pulp density at different hold-ups but cannot be extended to slurries varying in pulp density.

Jan 1, 1983

By A. J. Bowie

The discovery of the auriferous cement gravel deposits in and near Deadwood Gulch, Lawrence County, Dakota Territory, in 1876, created a mining excitement, and rush to the Black Hills. Numerous ten and twenty-stamp mills were built on Deadwood Gulch; Central City and the town of Deadwood sprang into existence, and became the centres of the mining industry of the Hills. Gold quartz deposits were subsequently discovered and located on a so-called mineral belt, extending from Whitewood Creek on the south, to Deadwood Gulch on the north. A northerly group of these quartz locations was purchased in December, 1877, by parties in San Francisco, who formed a company, incorporated under the name of the Father de Smet Consolidated Gold Mining Company. This company immediately commenced the work of exploration The deposits were proved to be extensive, and easily mined, but it was found that the ore, on an average, would not yield more than $10.00 per ton* of 2000 pounds. • At this trine the cost of supplies and materials in the Hills was high. Miners' wages were $3.50 per diem, and custom mills charged $6.00 per ton. The successful working of mines on "the belt" necessitated cheap milling. The ores being of so low grade,f this could be accomplished only with large and economically running mills. To insure the greatest possible economy, the Father de Smet mill

Jan 1, 1882

By J. H. Clemes

The process of leaching silver ores with sodium hyposulphite is comparatively new, and published accounts of the details and losses of the process are as yet very few. The following account of a careful series of experiments to determine the actual loss in this process may therefore be acceptable to members of the Institute. The ore treated was highly calcareous, and the principal sulphide present was iron pyrites. Following is an analysis by Professor Price, of San Francisco, of the ore treated : Per cent. Silica,..........15.13 Sulphur,.........13.31 Arsenic,.......... 9.82 Iron............ 17.33 Alumina,..........1.35 Zinc,...........4.92 Lead,..........1.78 Carbonate of lime,..33.78 Magnesia,.......... 2.58 100.00 Ten tons were crushed dry with a 30 X 30 screen = 900 holes per square inch. In order to feel our way with this ore, two experimental or "pilot" charges were roasted. Pilot Charge No. 1. Treated 1000 pounds in a four-hearth reverberatory. 8.30 p.m.—Entered fourth hearth, remaining there one and onehalf hours; sulphur began to burn. 10 p.m.—Changed to third hearth; ore became red-hot half an hour after entering; the fireplace was kept almost destitute of fuel. 2.30 A.M.—Changed to second hearth. Charge continued, giving off a large quantity of sulphurous fume; the fireplace was kept dark.

Jan 1, 1884

By T. Yeomans

NVI Mining’s Myra Falls operation is a forty-year-old underground mining operation feeding a 4,000 metric tonnes per day concentrator. The current mill, built in 1985, was designed to process a massive sulphide ore-body. This orebody, known as the HW, contains about 50% pyrite. Minerals of value are chalcopyrite and sphalerite, with precious metals occurring in all mineral types. By 1997, mining of a new ore-body, known as Battle-Gap, commenced. Mineralogically complex, the new orebody contains about 15% pyrite copper minerals, including primary chalcopyrite and secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite. Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected. Following significant metallurgical test-work, a new, fully sequential copper-lead-zinc flotation flow sheet and reagent scheme was developed. This sequential flow sheet was progressively installed and commissioned during 2006. Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, while increasing copper recovery by 10%.

Jan 1, 2009

By V. Bruned, K. Mohamed, A. Michaut

Orano Mining Somaïr uranium treatment plant (Niger) uses a pugging-curing process to leach uranium. Sulfuric acid, nitrates and water are added to the finely grinded ore in a rotary drum to leach uranium bearing minerals and solubilize uranyl sulfate ions. Reagents, sulfuric acid and nitrates, are the main OpEx of this process step. The economical optimization of their addition requires a thorough knowledge of the ore behavior in solution with these reagents. Orano Mining technical direction and Somaïr laboratories developed a model to predict the curing process uranium recovery surface with a limited number of parameters. Experimental laboratory work to fit the model needs to be done for each type of ore which can require a lot of metallurgical tests and would be time consuming. In order to optimize the required number of tests, an innovative experience plan was designed in parallel to the development of this model reducing the required number of tests to only eight. Once the parameters of the models are correctly fit, the comparison between the estimated values and the actual values for the uranium recovery is excellent (less than 0.5% error in average). Associated with an updated cost model of the curing process, this new recovery model helps the plant operator find the best set of reagents to maximize curing process profitability in the Somaïr plant day after day.

Jan 1, 2020