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By Hairong Zeng, Shahram Tafazoli, Edmond Chow

Blast fragmentation is one of the main parameters for optimizing mineral processing, but reliable data is difficult to acquire, resulting in unpredictable performance and efficiency. Crusher and grinder circuits are designed to process specific rock size ranges. Oversized rocks require extra energy to reduce before feeding into the process, and undersized rocks indicate that the process is not used to its full extent. Blast design is the key to controlling the blast fragmentation, so the ability to accurately monitor the particle sizes is imperative.

Jan 1, 2011

Jan 1, 1885

By M I. Pownceby, J Manuel, S Suthers, A Poliakov, E Donskoi, N Ware

"The mining industry is constantly seeking methods for optimising the exploitation of mineral resources, such as iron ore, in a sustainable and eco-efficient manner for economic and social benefit. When faced with resources that have mineralogical or textural complexity, poorer grades or geological variability, it is particularly important to apply a comprehensive geometallurgical approach to the development of the mining operation, from resource definition through to processed product. Integral to this approach is the quantitative characterisation of representative samples across the whole orebody.A key factor that associates the geological characteristics of iron ores to their processing response is ore texture. While the classification of samples on the basis of chemical or physical properties alone is often not sufficient to predict their processing behaviour, classification and quantification of texture types can be effectively correlated to metallurgical performance in processes such as blending, beneficiation, pellet making, sintering and ironmaking. This paper describes some of the research conducted by CSIRO pertaining to the design and rationale of a texture-based classification system for Australian iron ores; some of the tools developed and used to apply such classification; and the application of the generated data to quantifying, modelling and predicting sintering behaviour and performance in the blast furnace.CITATION:Suthers, S, Pownceby, M I, Manuel, J, Ware, N, Donskoi, E and Poliakov, A, 2016. Geometallurgical Characterisation of Australian Iron Ores – from Ore to Processed Product, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 351–360 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Chao Li, Lim Hongxu, Yuyue Wang, Xie Yang

"A intergrated process of sulfuric acid leaching, sodium chloride leaching, lead chloride crystallization, lead hydroxide synthesis and roasting was carried out for the recovery of lead, cadmium, copper and zinc from lead smelting dust containing various metals. The results showed that the separation of cadmium, zinc and copper from dust could be obtained after sulfuric acid leaching and corresponding leaching rate were 92.12%, 90.25% and 88.26% respectively. The subsequent sodium chloride leaching carried out for lead with optimized parameters as: sodium chloride concentration 250g/L, leaching temperature 90°C, leaching time 2h, pulp density 33g/L, 0.12mol/L CaCh; The lead compounds crystallization rate reached 86.67%, and then transferred into mPbO·nH2O, the product of 98.66% ß-PbO could be obtained through roasting under 502°C. In the end, a feasible method of ß-PbO preparation from lead containing dust was put forward.IntroductionThe pyro-metallurgy flue dust from smelting lead activities are often stockpiled and pose potential environmental risks due to the heavy toxic elements, such as Pb, Cd, As, Cu, Cl, and Zn which are contained in the dust. With the rapid depletion of rich ore resources in recent years, it has become increasingly more financially attractive to recover valuable metals from previously stockpiled dust, while simultaneously reducing the potential of environmental pollution from toxic elements contained in the dust. Nowadays, pyro-metallurgical and hydrometallurgical routes or both combined methods can be developed to treat secondary materials such as lead ash, leach residues etc. By comparison the hydrometallurgical processes are often considered more eco-friendly.Some chloride leaching processes for recovering lead have been employed using either NaCl, or MgC2 and CaCl2, or FeCl3 [1] The effectiveness of the brine leaching method is based on the formation of complex metal chlorides in concentrated chloride solutions [2] Similarly, Other metals such as zinc, cadmium and copper contained in the flue dust are often treated with sulfuric acid, hydrochloric acid, ammonium solution and sodium hydroxide etc. as lixiviants [3] The metals from leach solutions thus has been obtained by precipitation, ion exchange, solvent extraction or replacement [4]"

Jan 1, 2014

By Leonardo Mota, Lucas L. da Costa, Milton B. Filho, Sergio N. Monteiro, Helion Vargas, Tammy G. R. Portela da Silva

"A natural biofoam extracted from the buriti palm tree has shown characteristics for potential substitution of synthetic foams. In the present work, a photoacoustic thermal characterization was performed on buriti biofoam samples. An open photoacoustic cell technique and a photothermal rise method performed under continuous laser illumination were employed in order to determine the thermal diffusivity and the specific heat capacity of such material. In addition to their intrinsic values (finger print), these physical parameters represent the light-into-heat conversion efficiency and the amount of heat stored per unit volume, respectively. The results showed that the buriti biofoam presents thermal properties that permit its use as an effective insulation material.IntroductionSolid foams are very light materials with increasing engineering applications [1]. A natural biofoam obtained from the petiole of the buriti palm tree (Mauritia flexuosa) has been recently investigated [2-4]. The evaluation of the buriti biofoam properties and the characterization of its microstructural aspects have shown that this biofoam has a potential as a new engineering material with very low density. Additionally, its reduced open porosity and low absorbed humidity revealed a promising material for packing and floating applications. In fact, this buriti biofoam, extracted from the palm tree natural of the north region of Brazil, is being used by the low income population as a modest substitute for Styrofoam® [1].As a potential insulating material, the buriti foam needs to be characterized in terms of its thermal and acoustic properties. A preliminary investigation [3] on the thermal behavior of this natural biofoam by thermogravimetric analysis, TGA, and its derivative, DTG, as well as differential scanning calorimetry, DSC, revealed parametric conditions associated with water loss and structural decomposition. Both the surface humidity and the release of hydration water were determined. Different decomposition events were attributed to both, more rigid as well as to more flexible molecular segments. Table 1 depicts technical data obtained so far for the buriti biofoam. These data are compared to those corresponding to Styrofoam®."

Jan 1, 2011

By Anderson José Beber

O trabalho apresenta os resultados da aplicação de um novo oxidante moderado em uma grande torre de resfriamento utilizada em sistema de geração de energia de uma grande usina no sul do Brasil. Esta torre de refrigeração utiliza água de efluente tratado (tratamento terciário Esgoto doméstico) como fonte de reposição. Com aplicação desta nova tecnologia, houve uma melhoria tanto no controle microbiológico como na taxa de corrosão. Além disso, a planta foi capaz de aumentar o ciclo de concentração, resultando em economia de água, produtos químicos e menor geração de efluente, possibilitando economia superior a R$ 500.000/Ano, aplicando conceito de reuso.

Oct 30, 2017

By Michael Forrest, John Roadifer, Glen Gorski

"The Calaveras Dam Replacement Project (CDRP) requires large disposal sites to store excess excavated materials that could not be utilized for dam construction. Because of access restrictions during design, the disposal site rockfill toe dike area at the edge of the reservoir could not be explored to evaluate soil conditions. As such, the site had to be explored as part of the construction contract. Exploration revealed very soft clay and loose silty sand up to 40 feet thick that would not be able to support the rockfill dike at the toe of a large disposal site fill. Several alternatives were evaluated to stabilize these soils. Based on constructability, cost and risk considerations, cement deep soil mixing (CDSM) was selected as the preferred method of soil stabilization. The challenge was to design and construct the CDSM stabilization to minimize construction delays. A joint effort by the design engineer, construction manager and contractor achieved CDSM stabilization in about three months, from design through completion of construction. A rigorous quality control program included compression testing of both wet grab and cored soil cement samples to demonstrate that specified strength requirements were being achieved.INTRODUCTIONDisposal Site 3 (Figure 1) is one of the primary CDRP disposal sites having a height of 240 feet and a storage capacity of about 2,500,000 cubic yards. An approximately 40-foot-high rockfill dike at the base of the disposal site provides an erosion resistant toe for the disposal site. The rectangular foundation area shown in red was not able to be investigated during design because of access restrictions."

Jan 1, 2015

By VAN. H. MANNING

Probably no year in the history of the United States showed greater progress in the mineral industries than 1916. Although this progress was undoubtedly stimulated by the war in Europe, which caused extremely high prices for some of the metals, yet the fact remains that mining is being regarded more as a business and less as a speculation, and the benefits of business methods are becoming evident. Practices that were almost universal a few years ago have been largely abolished, the mining public has been brought to recognize the folly of wasteful and dangerous methods, and there is a gratifying unanimity of opinion in regard to the conservation of life and health, as well as of our mineral resources. The people of the United States realize more fully than ever before the extent and value of the country's mineral resources and the possibilities that await intelligent and well-directed efforts at utilization. In the past, economic reasons caused deposits of valuable metals and industrial materials to lie idle; commercial reasons, many of them not truly economic, led to the waste of valuable constituents in many ores; the recovery of minerals from the ground was too often incomplete and accompanied by uncalculated loss; and the treatment of ores in mills and smelters saved altogether too Iowa proportion of the metals sought. Now better methods are being tried on every hand, and the unparalleled record of the year is largely due to the success of these efforts. According to the preliminary estimates of the United States Geological Survey the output of metals and minerals in this country in the calendar year 1916 had a total gross value of slightly more than $3,000,000,000. For many metals and minerals the figures broke all previous records, the new records of some products, as compared with 1915 figures, being as follows:

Jan 1, 1917

By J. G. Cullain

Inco Limited is an integrated mining, smelting, refining and manufacturing company with operations located worldwide. The Ontario Division operations consist of 13 mines and 10 processing facilities located in Sudbury, Port Colborne and Shebandowan. The scope of our utilization of energy in the Ontario Division in 1976 included in excess of 2.2 billion kilowatt hours of electric power, 12 billion cubic feet of natural gas, 60 million Imperial gallons of residual oil and smaller quantities of other fuels. In addition to the primary energy consumption, waste-heat energy is recovered in various operations throughout the Division, thereby reducing our primary energy requirements. Total expenditures for primary energy alone in 1976 exceeded 60 million dollars. Energy management studies were initiated by Inco's Utilities Department in late 1972, and resulted initially in a program of electric power cost reduction. This program produced significant results by improving the use of the water available for our hydraulic generation facilities and by a comprehensive peak reduction program. Our experience showed that a program of peak power control creates an awareness of both peak and energy costs, and thereby encourages a general reduction in the electric energy consumption as well as lowering the peak demand. Energy management is a continuing program at Inco and, recently, a formal energy management policy and program was instituted. Energy management committees were formed in each plant or mine area to identify the major areas for energy; consumption, thereby isolating areas with large potential energy losses, and determining immediate action which will improve the energy efficiency or reduce the energy waste within their respective areas. A decentralized program with good cross-communication between all committees was felt to be the best method of providing an on-going effective energy management program. In the future, the projections of dwindling fossil-fuel supplies in Canada and the resultant spiralling energy costs will further emphasize the need of sound energy management practices for all Canadian industry.

Jan 1, 1977

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 Barrie A. Wigmore

There are two aspects of financing western coal development -- whether there is going to be enough money to finance the prospective large development of the industry, and the specific techniques of raising money for that development. To take the first question of whether there is going to be enough money around to finance your industry, I think it is quite clear that the restrictions on the development of western coal are going to be non- financial. Environmental impact problems are creating the greatest delay in coal mine development, at the moment; but getting enough personnel, mining equipment, railroad equipment, and failure of the Department of Interior to act on leasing federal coal lands all appear likely to create significant bottle- necks in the development of western coal -- larger bottlenecks than financing. Financing appears straightforward for the industry. There are many projections of the financing required to meet Project Independence goals. The National Academy of Engineers estimated that development of 500 million tons per annum of western coal would be necessary by 1985 to meet the Project Independence goals which might require $20 billion of capital spending. It is generally agreed that 500 million tons a year is not a realistic possibility. Carl Bagge?s estimate of production of 250 million tons a year by 1983 appears a more reasonable projection. Development

Jan 1, 1976

By J. E. Tress

The Bureau of Mines prepared submicron tungsten powder by reducing tungsten hexachloride with hydrogen. The particle diameters of the resulting tungsten powders ranged from 0.015 to 0.046 micron. Within the limits of the variables investigated, no clear-cut correlation was found between process conditions and final size of the powder. Oxygen was the major contaminant in the product; being present both as an adsorbed gas and as suboxides of tungsten. Studies showed that the powder yielded compacts of approximately 45 per-cent of theoretical density when compacted mechanically. Low-temperature sintering produced more rapid densification in these compacts than in compacts prepared from conventional powders. Adding up to 20 percent ultrafine powder to conventional tungsten powder caused an increase in density upon compaction with maximum densification occurring at approximately 12 percent ultrafine powder.

Jan 1, 1966

By G. T. Lineberry

Horsepower requirement is recognized as a most important equipment characteristic. Other critical equipment characteristics will be isolated and analyzed by traditional operations research techniques, using off-highway trucks as an archetype. A computer search technique has been developed, employing various production and cost analyses. With this model, the optimum combination of horsepower, capacity, and velocity can be found, minimizing handling cost per ton. An example of the program's use and interpretation of its results will conclude the paper.

Jan 1, 1984

By J. E. Danoczi

Shore Gold Inc. (Shore) is presently designing a diamond processing plant for the Star and the Orion South kimberlite deposits in the Fort à la Corne (FalC) area in central Saskatchewan. The first step in the plant is diamond liberation and occurs in the comminution section. Diamond liberation is the process of breaking up the kimberlite rock, as gently as possible so as not to damage the diamonds. Autogenous grinding mills (AG mills) use a combination of impact crushing, abrasion and attrition to break up the kimberlite. The forces that occur during the actions of abrasion and attrition cause the kimberlites to break up preferentially along lines of weaknesses which offers a ?diamond friendly? method of comminution. Hard competent kimberlite is commonly found in the diatreme zone as well as the root zone of the volcanic pipe and is the source of kimberlite for most of the Southern African diamond mines. Softer kimberlite is typically found in and around the crater area of a volcanic pipe and it is this kimberlite that makes up the majority of kimberlite for both the Star and Orion South deposits. These softer kimberlites can be readily broken up using abrasion and attrition imparted by AG mills. In order for Shore to benefit from the softer kimberlite found in the Star - Orion South diamond project, two large (10.97 m diameter x 7.10 m long) AG mills were designed for the comminution section based on extensive test work and simulations by Metso Minerals (Metso).

Jan 1, 2012

By Diana K. Schimmelpfennig

Assessment of revegetation success on mined lands is a difficult, time consuming task and has been the subject of a number of controversies. Present regulations require that both plant cover and aboveground plant biomass be measured for use in making that assessment. Of these two variables, biomass is the most time consuming to measure and requires destructive sampling, a most undesirable requirement on fragile, recently revegetated areas. On the other hand, plant cover can be estimated using the point-frame method which is relatively nondestructive. In addition, vegetation can be sampled more uniformly with the point frame and in less time if species composition measures are to be made. A study was done to evaluate the predictability of aboveground biomass production on revegetated mined sites and adjacent native prairies using plant cover estimates made with the point frame method. The predictability of biomass production by cover estimates bears on the need for both measurements in assessing revegetation success. In general, a positive, statistically, significant correlation was demonstrated between plant cover (estimated by the point frame) and aboveground biomass (estimated by the harvest method) regardless of community type (mined or native), species composition, diversity or level of biomass production. However, the latter did have their effects on the relationship and must be accounted for in any predictive equations (that is to say, the predictive equations must be considered site-specific). Considering the relationship observed between the two parameters, cover estimation may be a sufficient indicator of revegetation success, especially where time and minimization of disturbance are critical.

Jan 1, 1982

By Matt Kilburn, Liming Lu, Steve Suthers, Alexander Edenton, Rodney Smyth, Matt Adam

"Magnetite concentrate is naturally good for pelletising. However, due to the depletion of reserves of traditional high grade hematite iron ore worldwide, the usage of magnetite concentrate in sintering is expected to increase substantially. Magnetite concentrate is typically high in Fe grade and releases extra heat when oxidised to hematite. This will not only improve the quality of agglomerates produced, but also have a potential beneficial impact on the fuel consumption of the agglomeration process. There are an increasing number of magnetite projects currently being considered and developed. However the concentrates from some of these projects are too coarse as pellet feeds and much finer and denser than normal sinter feeds. Accordingly, special strategies are required in order to utilise the coarse magnetite concentrates at high proportions in pelletising and sintering. This paper discusses various raw material preparation technologies and blending optimization methods demonstrated to be effective for improving the sintering and pelletising performance of coarse magnetite concentrates. Pre-granulation and addition of binders, such as hydrated lime, were found to be particularly efficient in recovering the sintering productivity of sinter blends containing magnetite concentrates. In pelletising, HPGR (High Pressure Grinding Rolls) grinding enabled production of good quality pellets from 100% magnetite concentrates and optimized blends containing up to 70% magnetite concentrates also formed good pellets.INTRODUCTION Magnetite concentrates are often used as feed materials for pellet plants or sinter plants depending on their grades and grain sizes. To achieve the required quality of green and fired pellets, the concentrates often need to be ground very fine (80% passing 38- 45 m), which inevitably consumes a great amount of energy. Therefore, efficient grinding processes are required to reduce the amount of energy consumption needed to achieve the sizing and chemical specification of pellet feeds. The use of magnetite concentrates in sintering has the potential to improve sinter chemistry, which is deteriorating over time due to the slowly decreasing grade of direct shipping iron ores around the world (Yang and Mathews, 1997; Yang and Witchard, 1998, Yang and Davis, 1999; Yang 2005). However, methods are required to allow the utilisation of high levels of concentrates in sintering while maintaining productivity and sinter quality (Han and Lu, 2017)."

Jan 1, 2018

By Alaina Mallard, Katie Schumacher, Jannette Chorney, Grant C. Wallace, Jerome P. Downey

Commercial ceramic carbide operations require large thermal and mechanical energy inputs in order to produce a powder product. A process that could reduce the energy requirements needed to make these materials would allow for these materials to be implemented in a greater number of industrial applications. In this study, silicon carbide (SiC), tungsten carbide (WC), and molybdenum carbide (Mo2C) were synthesized via the carbothermal reduction of activated carbon loaded with silicate, tungstate, and molybdate anions adsorbed from aqueous solutions. Carburization was carried out under reducing and inert gas atmospheres, at temperatures lower than those utilized by commercial operations. Silicon carbide “whiskers” were synthesized under H2 at 1400 °C, while molybdenum carbide and mixed crystals of WC, W2C, and W were synthesized at temperatures below 1000 °C. X-ray diffraction and scanning electron microscopy were used to characterize the carburization products, and inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to determine the degree of adsorption onto the activated carbon matrix.

Mar 1, 2018

By Surendra Kumar Biswal, Sachida Nanda Sahu, B. C. Meikap

The unutilized iron ore fines (IOF, − 10 mm, 45% to < 60% Fe(T)) left at various mine sites during blasting and processing are rich in goethetic-hematite associated with high clay and considered a potential iron ore resource. The variation of loss on ignition (LOI) from mines to mines is based on the goethite and clay mineral content. The clay containing below 45 μm is mostly brittle, causing beneficiation problems. The IOF has an LOI of 7.83%, with high silica (5.52%) and alumina (4.57%), and 57.17% of Fe(T) subjected to both conventional deep beneficiation (CDB) and magnetization roasting using high-ash non-coking coal to adopt the suitable upgradation process. The CDB and magnetization roasting concentrate has 62.61% and 67.58% Fe(T) with 64.69% and 85.19% yield, respectively. However, the presence of 6.40% LOI in CDB makes the ore challenging for pelletization. Characterization like X-ray diffraction(XRD), scanning electron microscope(SEM), and chemical analysis was used to assess the concentrate quality and potential industrial application.

Jun 4, 2022

By William Gleason

While a fleet of 100 t (110 st) haul trucks were busy removing overburden from the open pit mine in the distance, a host of dignitaries, including congressmen and California state representatives, gathered for Molycorp?s official groundbreaking ceremony at the Mountain Pass Mine on April 20. The mine, recognized as arguably one of the richest rare earths deposits in the world, is at the center of Molycorps? strategic ?Mine to Magnets? plan. It aims to secure America?s future supply of rare-earth-dependent technologies by developing a strong domestic rare earth industry. Molycorp identifies rare-earth-dependent technologies as those that cannot be produced without rare earth materials. The list of these technologies is long and growing. It encompasses everything from personal electronics and batteries for hybrid cars to permanent magnet generator wind turbines and national defense applications.

Jan 1, 2011

By A J. Weston

Block or panel caving technology is far removed from that of the top slicing and block caving of the late nineteenth or early twentieth centuries. The rapid mechanisation and expansion of these methods in the late twentieth century was as much a result of the change of the technology of the unit operations of development, ground support, drilling and blasting and transport as it was of the advances in geotechnical understanding and practice. The small footprint gravity and scraper block caving mines with boundary weakening, rail transport and shaft hoisting of the early to mid-twentieth century have been replaced by massive high lift panel caves using preconditioning of the ore, large load-haul-dump units, adjacent crushers and conveyors to surface. The technology changes in the unit operations are described and the drivers for these changes examined.CITATION:Weston, A J, 2016. The evolution of block caving technology, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 265–274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016