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By D. R. Wilburn

his summary of international mineral exploration activities for the year 2011 draws upon available information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents [ ] analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia; 2) regional and site-specific exploration activities that took place in 2011 as compiled by the USGS and 3) regional events including economic, social and political conditions that affected exploration activities, which were derived from published sources and unpublished discussions with USGS and industry specialists.

Jan 1, 2012

By Yuanhong Qi, Xun Fu Wang, Tao Fu, Kunkun Cui, Yingyi Zhang, Jie Wang, Junmao Qie

With the sharp decrease of sulfide nickel resources, the nickel laterite is becoming more attractive as nickel oxide, nickel matte, and nickel-iron. This study investigated the mineral phase structure, chemical analysis, thermal properties, and element distribution characteristics of the rotten rock layer deposited in the Southeast Sulawesi Ophiolite Belt. The results show that the nickel laterite deposited in Southeast Sulawesi Island, Indonesia, belongs to the typical high-nickel and low-iron garnierite-type laterite. The concentrations of nickel and iron of the nickel laterite are 1.99 wt% and 17.55 wt%, respectively. The serpentine, olivine, clay, chlorite, hematite, and magnetite are the major minerals, and the pyroxene, actinolite, limonite, and chromite are the minor minerals in the nickel laterite in Southeast Sulawesi, Indonesia. Serpentine and olivine are the main nickel minerals with an average nickel concentration of 3.65 wt% and 1.73 wt%, respectively. The Fe and Ni have homogeneity and symbiosis in the serpentine and olivine, and their concentrations are often positively correlated.

By J. Diao

In order to understand the flotation kinetic behavior of coal and associated mineral matter, a detailed investigation was conducted in a 2-liter Denver flotation cell using three high sulfur coals at three feed sizes, minus 28. 100 and 200 mesh. Subsequently. the flotation products were sieved into different size fractions and analyzed for their ash and pyritic sulfur content in order to delineate the effect of particle size on the rate at which each constituent floats. The results were tested with several different flotation kinetic models and the best model for coal was then chosen. The flotation rate constant and the ultimate recovery calculated from a kinetic model were used to delineate the effect of particle size, collector (dodecane) and frother (MIBC) dosages on the flotation kinetics of coal, ash and pyrite.

Jan 1, 1992

By R. R. Klimpel

This paper describes a series of mechanical flotation cell results run with various chemical reagent schemes designed to economically improve the flotation performance associated with selected industrially available coals. The emphasis is on the identification of practical flotation methods of processing coals containing unusually coarse and/or fine feed sizes, of increasing the recovery of oxidized and/or difficult to float coal, and of increasing the selectivity of coal over pyrite in high sulfur coals.

Jan 1, 1991

By L. A. Baker

The presence of goethite in a hematite ore has been shown to strongly affect the time of heating to the firing temperature. The investigation of spalling of single pellets and of packed beds has enabled free water and goethite spalling to be identified as separate phenomena. In addition, it has been shown that even for an 18 inch deep bed of green balls the free water and goethite drying periods can be considered separately. Based on this observation, a method of predicting production rate and hood temperature profile is presented. The method required knowledge of the ore goethite content, ore grind and the green pellet bulk density. Laboratory results were found to be in good agreement with actual plant practice and have led to improved process performance.

Jan 1, 1972

By Hongsheng He, Xiaofang Lv, Jianfeng Wang

This paper provided an overview of characteristics of limonite ores as well as their influence on sintering performance. Evaluation experiments focusing on basic characteristics, granulation characteristics, and high temperature sintering characteristics had been conducted by using two types of limonite ores, then the principles of high effective utilization technology of limonite ores were discussed, and the sintering pot tests were conducted. Limonite ores possessed low total iron content, high combined water content, high SiO2 content, large average particle size, low adhering particles proportion, high porosity, high water absorption rate, short water absorbing time, poor granulation ability, high melt formation ability, low melt fluidity ability, low melt penetration ability, high melt absorption ability, low bonding phase strength, and high forming ability of SFCA. By taking the technical measures of ore-proportioning optimization, increasing the proportion of burntlime and segmentation granulation, the usage of limonite ores could reach 50% in sintering.

Aug 27, 2021

By Miles L. Silberman

Three major suites of igneous rocks were erupted in the Great Basin in middle and late Cenozoic time. The first, most likely, resulted from sub- duction of a Pacific plate (Farallon plate) beneath the North American plate, resulting in eruption of andesitic rocks in the northern Great Basin between 42 and 43 m.y. ago. Between 34 and 17 m.y. ago, igneous activity migrated to the southwest, largely as eruption of volumincus rhyolite-quartz latite ash-flow sheets, ending about 17 a.y. ago with the onset of crustal extension and north-south-trending Basin and Range (rift) faulting. The second volcanic suite erupted between 17 and 8 m.y. ago in the northern Great Basin; is mostly basaltic or bimodal basalt-rhyolite. The third volcanic suite consists of andesitic and rhyolitic lavas and some basalt erupted between about 22 to 6 m.y. ago in the western Great Basin along the northwest-trending Walker Lane fault zone. Hydrothermal ore deposits are associated with all suites of igneous rocks, but the largest production has come from mines associated with andesitic rocks of the third (western Great Basin) suite. The oldest (34 to 42 m.y.) andesitic rocks (first suite) of the northern Great Basin have produced some large deposits; slightly younger silicic rocks of this suite are mostly barren. Many small ore deposits are associated with the 17- to 8-m.y.-old basalts (second suite) of northern Nevada.

Jan 1, 1976

By John A. L. Campbell

Surface dependent processes, such as froth flotation and flocculation, are important or potentially important techniques for combating some of the current major problems in coal preparation. In order to correctly apply or imporve a surface dependent process, it is of paramount importance to understand the interfacial phenomenon, especially the double layer properties, exhibited by the solid. The specific objective of this research was to determine the properties of the bituminous coal/liquid interface by an electrokinetic method, streaming potential, and to relate the findings, wherever possible, to the existing unit operations of froth flotation and flocculation. The electrokinetic properties of both the whole coal and its lithotypes were investigated. As part of the total investigation, the role played in the double layer by the reagents commonly employed in the surface dependent process was also established (1). These data will be presented at a latter date.

Jan 1, 1969

By MARK J. VANARELLI

Estimating groundwater inflows in rock deep tunnels is critical to the safety of personnel constructing the tunnel and the cost of construction. This paper presents two case studies for estimating steady-state groundwater inflows into deep rock tunnels. The case studies included the Chattahoochee and Nancy Creek tunnels. In this paper, statistical methods were applied to packer test data obtained from exploratory borings during geotechnical site investigations. A semi-empirical procedure was utilized for estimating groundwater inflows into these deep rock tunnels. The Chattahoochee and Nancy Creek tunnels are deep rock tunnels which exhibit radial flow conditions. For the radial flow condition, a statistical analysis presented in this paper indicates that the semi-empirical procedure works well; however, variations in the procedure and/or an insufficient amount of testing could lead to underestimations of the inflow quantities. Packer test data plotted in histograms were observed in all cases to be log-normally distributed for the radial flow condition. Modeling using Monte Carlo simulations was observed to be an effective tool for removing irregularities in the distribution of the data and incorporating high-end permeability data to derive reasonable groundwater inflow estimates.

Jun 13, 2021

By T. E. Masoner

The struggle to get the minerals industry seriously interested in high intensity wet magnetic separation* has been difficult. The high capital cost of the equipment, the lack of basic research, the lack of operating information, and the diverse characteristics associated with different minerals and ores have prevented the development and use of HIMS-W on a wide scale. The Climax Molybdenum Company, a Division of American Metal Climax, Inc., located at Climax, Colorado, was among the first companies in the Americas in recent years to support the development of HIMS-W to recover weakly magnetic minerals on a large scale. The Climax Molybdenum Company, one of the world's largest underground mines, processes about 40,000 tons per day of ore, from which about fifty million pounds of molybdenum disulfide are produced each year. By-products include tungsten, iron pyrite, tin, and some monazite.

Jan 1, 1968

By G. Wang, L. R. Moore, Y. Xiong, J. Gu

"Quartz is the second most abundant mineral in the earth’s crust. Not only does quartz have many valuable industrial applications, it is also one of the most concentrated gangue minerals encountered in the processing of other minerals. Minerals such as hematite, apatite, calcite, feldspar, barite, and many more. Numerous applications of industrial minerals are sensitive to the hardness and abrasiveness encountered with quartz minerals, while other applications may lead to processing challenges for the end user. Therefore, process and chemistry optimization must be applied to ensure optimal grade is obtained for these valued industrial minerals. Extensive studies have been conducted in processing various industrial minerals, thus achieving a range of quality specifications, which entailed the application of ArrMaz’s CustoFloat and CustAmine collectors towards the separation of quartz from other minerals. INTRODUCTION Industrial minerals often have the misfortune of the gangue mineral being very similar in surface charge, and coordination properties, to that of the mineral of interest. An example is seen in phosphate beneficiation, when dolomite can be a gangue minerals (Table 1). Therefore, the development of processing reagents are quite complicated. Some minerals, like clays, may be washed away. However, most require the manipulation of the pH, in efforts to fine tune the system to the narrow difference in isoelectric points of the different minerals, as well as the knowledge, and resources that are necessary to exploit the differences to yield and an optimal grade/recovery. In some cases, the application of a depressant may be required, such as the phosphoric acid commonly applied to achieve the optimal balance of grade/recovery for phosphate from a mineral with elevated concentrations of dolomite (Wang, 2016), or the application of hydrofluoric acid to assist in producing feldspar product from a mineral rich in quartz (Heyes, 2012).ArrMaz's CustoFloat and CustAmine product lines have successfully been applied to the processing of industrial minerals for more than 50 years. Applications include, but not limited to phosphate, sand (glass, foundry & high purity quartz), clays (feldspar, kaolin, etc.), and many carbonaceous and sulfate minerals. The successes of these 50 years are largely due to ArrMaz's ability to tailor make the processing chemistries to fit the ever changing and declining mineral feed grade and variations in water quality (Moore, 2015; Moore, 2016). This technical knowledge of mineral processing is strongly complimented by the intimate service programs in place at many of the beneficiation plants."

Jan 1, 2018

By G. A. Kordosky

LIX® 34 liquid ion exchange reagent, one of a totally new class of metal extractants, is discussed in terms of its properties. Specifically, these properties include improved selectivity for copper and greater recovery. Some comparisons to the well known General Mills' LIX® 64N have been made. Particular emphasis is given to treating solutions containing very low copper values and high impurity levels.

Jan 1, 1976

By R. Yang

This paper presents a kinematic approach for blast modeling with examples of blast models that were developed previously. A kinematic approach was applied successfully in developing blasting models that can simulate all blast design parameters for field applications. Several applied blasting models have been developed and applied widely in the world. A kinematic approach to blast modeling refers to using measurements of kinematic quantities such as the velocity, strain, or displacement and well-established assumptions to model blasting phenomena, rather than being restricted to use first principal of physics, such as, the stress- and material-constitutive relations. The kinematic quantities are easy to measure in the field. Due to the complexity and inhomogeneity of rock mass properties, using first principles of physics, many parameters of rock and explosive properties must be involved, which are hard or impossible to quantify. This creates a major impediment when trying to simulate the total process of blasting based upon first principles of physics. The 3D kinematic model for muckpile formation was developed and applied to open pit blasts. The multiple blasthole fragmentation model developed during recent years has been applied successfully to many mine sites around the globe. These models are typical examples of blast modeling using the kinematic approach, which enables the models to catch major trends of the blasting process and explicitly simulate full blast design parameters and complex geometries. Blast modeling using the kinematic approach results in easy model calibration and validation against field measurements and effective applications to practical problems. Using kinematic models of the muckpile formation and the multiple blasthole fragmentation model, this paper demonstrates the merits of the kinematic approach for blast modeling. New developments of the models were also presented in the paper, which illustrate the potential of the kinematic modelling approach.

Mar 2, 2022

Thermal pretreatment can significantly improve industrial comminution operations by reducing energy requirements and increasing mineral liberation. The effect of pretreatment using conventional and dielectric heating followed by quenching on the fracture properties of a number single and multiphase brittle materials has been investigated. The reduction in the impact fracture energies and particle strengths with and without pretreatment has been measured in precise single-particle experiments using the Ultrafast Load Cell. Variations in the fragmentation pattern caused by different pretreatments were assessed by measurements of the progeny size distributions. The differences in the effect of thermal treatment on single and multiphase materials are discussed based on the experimental results.

Jan 1, 1995

By Gordon M. Bell

Water has received little attention as a variable in flotation, even though it is a known fact that water hardness often has an adverse effect on purity and recovery, particularly on the flotation of non-metallic minerals. Because of this fact, process water used in some flotation plants is treated to reduce hardness to an acceptable level. In the laboratory, distilled water is usually used as the flotation medium in order to standardize conditions, whereas in flotation plants locally available water is used. At Rosiclare Works of Aluminum Company of America, Rosiclare, Illinois, where a vein-type of fluorspar deposit was being processed by flotation to make an acid-grade fluorspar concentrate until February of 1968 when the plant was closed, qualitative correlations had been observed between metallurgy and reagent consumption and the seasons of the year. The observed effects were thought to be due to seasonal variations in the quality of Ohio River water used as the flotation medium. Figure 1 shows the variations in total hardness and chloride contents of Ohio River water at Rosiclare for the period September 1964 through September 1967. During this period, the sulfate content varied from 85 to 245 ppm (as Na2SO4), the calcium from 90 to 160 ppm (as CaCO3) and the magnesium from 50 to 70 ppm (as CaCO3). The data in Figure 1 show that the total hardness and chloride contents are highest in the late summer and fall which are usually periods of low water and lowest in late winter and spring which are usually periods of high water.

Jan 1, 1970

By S. K. Sharma

The Bureau of Mines' Tuscaloosa Research Center is conducting research to develop a basic understanding of solid-liquid separation in order to improve the dewatering of fine particle slurries. In the present investigation capillary suction time (CST) of kaolin slurries was determined. The average specific resistance of the cake was also determined by fitting the CST data to the theoretical equations used in this paper. The experimental data were analyzed by a powerful computer-based method, chemometrics, that uses statistical techniques to remove error and to find the number of physically significant factors contributing to the data. Results showed that two significant factors explain the CST data.

Jan 1, 1991

By R. Benito

This paper describes the development of a life-of-mine schedule (LOM) for one of the world's largest known sedimentary copper-cobalt districts located in the Katanga Province, Democratic Republic of Congo (DRC). A particular feature of the Tenke Fungurume LOM schedule is the considerable number of pits/phases for scheduling, each competing to provide the best ore available to a capacity-constrained process facility. This paper discusses the LOM scheduling objectives and constraints, data preprocessing steps such as ore binning, block aggregation and clustering analysis as a scheduling aid, the mine scheduling approach and results and conclusions. Mining Engineering, 2011, Vol. 63, No. 8, pp. 39-47. Official publication of the Society for Mining, Metallurgy and Exploration, Inc.

Jan 1, 2011

By R. A. Wyman

"The froth flotation process was patented by E.L. Sulman, H.F.K. Pickard, and John Ballot in 1906 . . . . . . . . . .James M. Hyde installed the first froth flotation process in the U.S., about August 1, 1911, at the Basin Reduction Co. plant, Basin, Montana . . . . . . . . . .By 1914, 42 mining companies were operating or experimenting with the flotation process . . . . . . . . . .The period 1930 to 1960 saw the application of flotation spread to nonsulphide ores and become the key factor in the economic production of many industrial minerals". So states FROTH FLOTATION, 50th Anniversary Volume, published by AIME in 1962. It is interesting, to observe that the Mines Branch, now part of the Canadian Department of Energy, Mines and Resources, was established in 1907 through an act of Parliament entitled, "The Nines and Geology Act". In 1911, a mineral dressing group was formed and a laboratory was constructed. By 1921, an engineer was devoting full time to industrial mineral processing problems.

Jan 1, 1971

By E. Zahl, J. Whyatt, H. Lawson

The U.S. Mine Safety and Health Administration (MSHA) issued Program Information Bulletin P09-03 in April 2008, providing formal guidance on using programs that model the redistribution of stress during underground mining of coal. A key part of this guidance is visual observation and mapping of ground conditions. If a correlation between ground conditions and model output can be established, the model is considered to be verified, and can be used to guide mine design in similar ground. A simple scale is recommended for ranking observed roof, rib and floor conditions. This paper discusses optimization and implementation of a ground condition rating scheme in the gateroads of a deep underground longwall coal mine. Roughly 80% of each gateroad length deteriorated in a fairly uniform manner. However, this manner varied between gateroads, as did pillar size. The implementation of a ground condition mapping program, similar to that recommended in PIB P09-03, was successful in characterizing the ground response to mining in gateroads of a longwall coal mine.

Jan 1, 2013

SOLUTION MINING Solution mining techniques present a means of extracting soluble ores, particularly such materials as salt and potash, from horizons which are not accessible by conventional mining. In the process of dissolving materials, it is evident that solution may be complete or partial. In general, the solution mining operations described in the following section relate to complete solution of the desired compound. Even though the solution of material is complete, there may be instances in which insoluble material is present to a large extent either as granular separated particles or as insoluble layers. The process required for obtaining the desired product involves access wells to reach the deposits, sufficient water supply to yield the production goals, and the development of an underground cavity. The process of solution mining, therefore, depends to a great extent on three factors: availability of a relatively pure strata or formation of salt or potash to be mined, access well or wells, and adequate control of the solutioning process so that enlargement of underground cavities can be fairly well delineated. Since halites represent the most general ores mined by this procedure, the considerations which follow are based primarily on the production of sodium or potassium chloride. The producing formations may be in the form of bedded evc~porites wherein the salt member may be some 30 to 500 ft thick or from salt domes in which great depths of salt occur. Solution mining has been carried out to depths of nearly 10,000 ft. The recovery of saturated brine from wells drilled to effect the solution-mining process leads to further processing. In many instances, the procedures are relatively simple and involve simple recrystallieation or fractional crystallieation, while in others more complex flow systems are required before a final product is obtained. The intent of this section is to provide information relative to the basic procedures for obtaining materials which are soluble in water and to acquaint the engineer with the various aspects of the overall problem which in many instances, may become quite complex and present numerous difficulties. The storage of fluids, particularly hydrocarbons, underground has proven to be a very important part of industry operations. Cavities formed in salt provide excellent storage facilities. The formation of well-defined controlled configurations of such cavities has been possible because of better understanding of the solution process, wide experience gained over nearly 30 yr, and improved technology in drilling and completing wells, surveying caverns, and the operation of numerous types of systems. Solution mining techniques will improve in the future. Many facets of the simple operation of pumping solvents and extracting valuable minerals require further study. Developments undoubtedly will occur to further the processes of mining by solution. In addition to those whose names appear in connection with the individual subjections which follow, a major role in assembling and processing the material in this section was played by Dr. D. A. Shock, Central Research, Continental Oil Co., Ponca City, Okla.

Jan 1, 1973