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By E. P. Youngman

The rapidly growing demand for titanium pigments has aroused new interest in actual and potential sources of supply of titanium- bearing ores , which only a comparatively few years ago were almost unmarketable . This paper , which supplements a general circular entitled " Titanium" ( Information Circular 6365 ) , represents a summary of current trade literature and Government reports , together with some hitherto unpublished material that has accumulated in the files of the Bureau of Mines . The purpose of this pamphlet is simply to indicate the commercial possibilities of the deposits , and the discussion is confined almost entirely to the three commercial ores , ilmenite , rutile , and magnetite ( titaniferous iron ore ) .

Oct 1, 1930

By O. Llewellyn Jack

From September 1978 to December 1983, ESD Corporation (formerly a Division of FMC Corporation) undertook the development and testing of a bidirectional auger under contract with the U.S. Department of Energy. Underground testing began in August 1981 at Peabody Coal Company's Marissa Mine near Marissa, Illinois. The auger was developed to increase mine production and coal recovery without increasing land subsidence. It bored 4-foot-diameter by 10-foot-deep holes into pillars on 7-foot centers (each hole recovering 5 tons). All operating during this test was performed by maintenance personnel with the goal of finding ways to increase the machine potential. The maximum excavation rate achieved was 1.4 tons per minute. It was concluded that the concept of drilling short holes to extract coal from underground pillars without surface subsidence was practicable with a wheel mounted auger, but that more power was desirable for this mine, and that the hydraulically driven augering system that provided experimental versatility was not sufficiently reliable for production use.

Jan 1, 1983

By S C. Dominy

The gravity recoverable gold (GRG) parameter reflects liberated gold or gold-dominated composite particles that can be recovered by gravity separation. Recoveries depend upon mineralogy, in situ particle size and the comminution and extraction method used. Any ore bearing >15 per cent of gold greater than 50 ¦m in size is likely to have a GRG component. The principal characterisation methodology applied is the three-stage GRG (3GRG) test, based on a 40 kg to 100 kg sample. An alternative is the single-stage GRG test (SGRG), which is generally based on a 20 kg sample. Experience has shown that GRG values can vary throughout an orebody, particularly within different grade and/or mineralogical domains. Test programs must consider sample frequency and mass. This study demonstrates the variability of GRG results based on different sample masses. Consecutive underground faces on a coarse-gold dominated quartz vein were sampled taking five different masses from each. Each sample was processed using a SGRG approach. Subsequently, each development round was batched through a small gravity production plant. The results show that the small samples understate the plant GRG and show inter-sample variability. Large samples show less variability and a SGRG closer to the plant GRG. A high SGRG broadly correlates to higher gold grades, more coarse gold and larger gold particles. These results are intuitively correct, but indicate the likely challenges of sampling for gold recovery in heterogeneous systems.CITATION:Dominy, S C, 2013. Variability of gravity recoverable gold values in relation to test sample size, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 293-302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By R. H. Storch, D. C. Holt

During reconnaissance investigations of more than 300 stream areas in Idaho to determine the potential value of ilmenite in black - sand placer deposits 46 deposits were explored by churn drilling , trenching , test pitting , or shafting . The component mineral content and total black - sand content were determined for more than 8,690 reconnaissance and exploration samples . Data compiled during the investigation indicate a good potential for large , low- grade deposits containing ilmenite , monazite , columbite , euxenite , uranothorite , and other radioactive black minerals and accessory black - sand minerals . The data also indicate most deposits will be economic only if several component minerals can be recovered as coproducts .

Jan 1, 1963

By Antonio Fabiano de Oliveira

The aim of the present research work is to study the influence of hard chrome covered skin pass cold rolling rolls using 2D/3D surface topography, i.e. roughness characterization. The common stochastic structure Shot Blast Texturing (SBT) does not meet all requirements related to the production line regards to the finished product. The Hard Chrome layer, applied on these SBT rolls, can improve the sheet surface quality and is of fundamental interest mainly for those steel mills that do not have another alternative to new surface structures such as those that may be provided by the EDT, LT, EBT, etc. methods. The function of the generated surfaces, obtained by these different methods is going to influence the tribological properties during the subsequent forming processes. On the other hand, they can increase the product final cost or require large investments to obtain such surfaces. The results here presented are in accordance with other recently published research work, showing that there is a relationship between these parameters, and that further detailed studies are needed.

Aug 17, 2017

By Frank E. Williams

Nuclear detonation data were accumulated, studied, and evaluated by the Bureau of Mines to visualize how nuclear explosives might be used in a shale?-oil industry, The evaluation shows that the Green River Formation at the semi-isolated locale of Piceance Creek Basin, in northwestern Colorado; is thick and widespread enough to warrant consideration of nuclear mining in lieu of conventional methods, Because cost data for nuclear explosions are limited; cost comparisons are made largely by assumptions. Also described are the history of the shale-oil industry, the geology and size of oil-shale resources; and conventional mining methods and processing technology.

Jan 1, 1969

By H Rossiter, A Maddever, J Market, P Jeanneau, A Virani

It is generally acknowledged that the head grade of the world’s copper resources is declining. Accordingly, there is an increase in the volume of resource material being mined and processed to maintain copper production. This has led to increases in cost base accompanied by reductions in Life of Mine (LOM) Net Present Value (NPV). The higher tonnages of material mined are driven by increased quantities of lower grade material required to satisfy the short term mine model. In turn, this has brought an increased focus on sampling and assay methods, since any error associated with estimating the grade of each block and determining its correct destination serves to magnify the losses that will occur. Presently most open-pit copper mining operations use blasthole sample assays to feed their shortterm model. The problematic nature of blasthole sampling is well documented (Engström, 2017), particularly the poor timeliness of the data and the significant errors that are inherent to the technique. Methods to improve grade control, such as drilling a separate grade control grid, have been proposed but come with their own cost, logistical, and accuracy shortcomings. A recent development in grade estimation is the Pulsed Fast and Thermal Neutron Activation (PFTNA) downhole logging probe. Deployed on an efficient semi-autonomous platform, PFTNA is being aggressively adopted in the Australian iron ore industry. The technology provides in-situ elemental analysis of the geological formation, delivering high accuracy, high efficiency, near realtime data from a sizeable measurement volume. In this paper we consider the application of the technology to copper. Whilst there are several operational components to such a value proposition, we focus on the benefits of improved gradeestimation. A simulated copper mine is used to model the quantum of improvement expected from a reduced grade-estimation error, which reduces the likelihood of misallocating material to the wrong destination, which in turn increases NPV.

Nov 10, 2020

By N. Moelans, I. Bellemans, K. Verbeken

Metallic droplets can remain attached to solid particles within liquid slags, resulting in production losses in several movement of solid particles in the liquid slag in a system, considering the attachment of liquid metal droplets to solid slag and on the resulting microstructures is investigated as a function of the velocity of the particles. For all wetting For the amount of metal attached to the particle, a clear trade-off was found between the speed of motion of the solid particle and the wetting regime.

By Martin Walker, Joseph Ang, Jongwon Lee, Alvin Bayudanto, Lilian Lorincz, Morteza Khorshidi, Wenyong Rong

This paper presents a case history of liquefaction susceptibility evaluation study for a major infrastructure project in the San José area. The subsurface material of the study area consists of Holocene alluvial deposits composed of interbedded and crosscut clays and silts, sands and gravels. The simplified approach for liquefaction triggering evaluation was carried out using both CPT data and SPT data representing site’s seismic capacity and the peak ground acceleration associated with a return period of 975 years at ground surface representing seismic demands. Site-specific cyclic stress ratio (CSR) profiles as seismic demand are also estimated from one-dimensional site response analysis. The simplified approach uses empirical depth stress reduction factors (rd) based on generic shear wave velocity profiles to account for the non-rigid response of the soil profile in estimating CSR. The CSR profiles of the simplified procedure were examined by completing site response analyses using site-specific soil profiles to represent site-specific seismic demands in the liquefaction triggering evaluation. The paper concludes with a comparison and discussion of the liquefaction evaluation examining results from CPT versus SPT data, and the comparison of CSR profiles from the simplified procedure versus site-specific response analysis.

Sep 8, 2021

By Yong-neng Feng, Xiao-ping Chen, Wei Guo

"While the uniaxial compressive strength of rock has been extensively investigated, the relation between the saturation and natural compressive strength is relatively unexplored. This paper studies on 1865 statistical data of Chongqing Rail Transit Line 1 and Line 6, which located in the Middle Jurassic of Shaximiao formation. The research focuses on the relation between the saturation and natural compressive strength. The statistical data are categorized and quantified in order to ascertain the softening properties of sandstone and sandy mudstone. The findings suggest that the saturation compressive strength is significant effected by its natural compressive strength, and an empirical formula is introduced to explain the relation. These findings have implications for researchers and engineer who concerned with Chongqing rail transit construction.INTRODUCTIONIn the engineering construction and surrounding rock classification, the uniaxial compressive strength index (Ministry of Water Conservancy, 1995; Ministry of Railways, 1999) is one of the essential parameters of rock mass. Usually, there are two types of the uniaxial compressive strength index, natural and saturation compressive strength, and the ratio of them is the softening coefficient. Most of the previous studies on rock strength had focused on the influence factors (Liu et al., 2008; Liu et al., 1998; Liu et al., 2013; Wang, 2013; Zhang et al., 2008; Zhang et al., 2010; Zeng & Lin, 2003) with experiment and in-situ tests. But few publications that reports a long and formal research project on the relationship between natural and saturation compressive strength. In order to figure out this issue, this study investigated the distribution of Solidity Classification of Rock Mass and softening coefficient based on the statistical data of Chongqing Rail Transit Line 1 and Line 6. Based on the analysis, an empirical formula was proposed to explain the relationship."

Jan 1, 2015

By W Patton

Investment decisions in the mineral resources sector are made on the basis of an assessment of the economic potential for a mineral deposit. Given the supporting information for the location, scale, and quantity of the commodity of interest, miners and investors aim to make risk-informed decisions when considering further investment. The objective of resource classification is the synthesis of various types and quantities of geologic information used in resource model construction to assign confidence categories to the estimated mineral resources, which can then be used to support informed economic decisions. In this paper a risk-based classification scheme for iron ore mineral resources using conditional simulations is presented. The method involves categorisation of each block according to a confidence level, considering expected recoveries from a kriging model over mining production volumes. The realisations of the simulated model are used to assign risk-based confidence categories to zones of the ore deposit. One motivation for this work is to assess the sensitivity of the scheme to geologic uncertainties. Specifically, that which uncertainty in the layout of mineralising alterations and weathering overprints influence variabilities of associated rock properties and the likelihood of obtaining expected ore recoveries. It is shown these risks have material implications for a project’s economic potential. How the scheme can be extended to the grade control context and the value subsequent grade control activities is also quantified.

May 24, 2023

By Olli Haavisto, Lauri Koresaar, Navid Khajehzadeh

In recent times sustainable minerals processing is an important topic in research. Sustainable mining is linked with efficient use of energy and human resource in all process stages including beneficiation of the ore. Controlling and optimizing the recovery while preserving the grade of the concentrate is extremely important in flotation plants. This development requires new technological solutions and has given rise to the multitude of application areas for lasers. X-ray Fluorescence (XRF) and Laser-Induced Breakdown Spectroscopy (LIBS) are currently two of the predominant non-contact and direct analysing methods in industry. LIBS and XRF measurement techniques both have high capabilities for measuring elements. LIBS has a very simple and easy-to-implement spectroscopic setup, wider range of elements can be detected with online LIBS and measuring light elements is simpler by LIBS compared with XRF. It is of great interest to extract mineralogical information from the elemental results with no modification on the measurement setup. In order to achieve this, more advanced interpretation of the elemental peaks of LIBS spectra is required. Therefore, the major focus of this research is about measuring mineral concentrations from the elemental lines of LIBS spectra using advanced statistical methods. This accomplishment provides knowledge about mineral concentrations from the real-time assay data of the slurry LIBS analyzer. Consequently, this paper first discusses an analytical method called partial least squares regression leading to rapid mineral identification from the elemental contents of the LIBS technique. Then the technique is employed to analyze the mineral contents quantitatively through the information acquired from an on-stream LIBS slurry analyser. This can lead to many benefits such as rapid control of concentrate quality, enhanced recovery, saving time, energy and manpower.

Jan 1, 2016

By Ankit Jha, RICHARD AMOAKO

In this paper, we examine the challenges associated with the use of empirical rock fragmentation models. We highlight key parameters omitted by these models, and propose a machine learning approach that incorporates these parameters, leading to a simple, yet more accurate approach to blast design.

Feb 1, 2020

By Stanley J. LeFond

Brazil is one of the most outstanding examples of economic development of our time. Its amazing growth record is substantiated by a GNP which has increased at an average rate of 92% for the period 1968-1970 and estimates for 1971 range from 11.7-12.5%. Hence, this growth, coupled with a more relaxed attitude of the Brazilian government towards foreign participation in business opportunities and the remittance of profits out of the country, has caused many exploration companies to reevaluate the potential of Brazil. Despite recent press notices and publicity, Brazil is still not a mining country in the tradition of Canada or Australia. It is still basically an agriculture and manufacturing country.

Jan 11, 1973

By D Bertoldi, C Haines

"The Waihi Gold Mine (WGM) operated by OceanaGold New Zealand Limited is a wholly owned subsidiary of the OceanaGold Corporation of Australia. Traditionally WGM has stockpiled and processed separate campaigns of open pit and underground ore. The ore is processed via a conventional semi-autonomous grinding (SAG) / ball circuit (SABC). The low aspect SAG mill operates in a closed circuit with two 20" cyclones, whilst the ball mill is also a closed circuit with a 10" cyclone cluster. A major wall movement in April 2015 ceased open pit operations indefinitely, 18 months ahead of the mining plan. This immediately reduced the forecast mill tonnage leaving two options: begin campaign milling or change the operating strategy and target lower throughput. Additional cost pressures necessitated improved milling cost efficiency. The immediate ore restriction limited processing alternatives to within the existing major infrastructure. Available comminution circuit survey data laid the foundation for developing a comminution model using the JKSimMet™ software package (version 6, created by KJTech). A number of flow sheet variants were then evaluated based on predicted throughput and efficiency. The comminution models suggested opportunities for improved efficiency lay in reducing throughput and increasing utilisation rather than on/off campaign milling under the existing operating philosophy. A series of process alterations followed, delivering new cost efficiencies that maintained the current $/t processing cost. This paper aims to review the change in circuit performance and examine the decisions and challenges faced following the transition from a high tonnage SABC circuit to lower tonnage SABC circuit.Citation:Haines, C and Bertoldi, D, 2016. The Transition from Semi-autogenous to Autogenous Milling at Waihi Gold, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 303–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By L. E. Djingheuzian

IN 1953, Lewis (1) published an article which brought forth a great amount of discussion by grinding engineers. In his contribution to discussion the present writer (2) suggested that, for the most efficient performance of a ball mill, there must be a .definite relationship between Cn, per cent critical speed, and V p, per cent mill volume occupied by the ball charge. Later, he ( 3) was able to publish some grinding data from Wright-Hargreaves milly which appeared to bear out this contention. It is with this view to establishing a fundamental relationship between Cn and Vp that the idea of this Forum was conceived. Accordingly, a questionnaire was prepared and copies of it were mailed to over eighty Canadian mill operators. This questionnaire did not include a question on dilution on the assumption that each mill operator was using the most efficient dilution for his operation, nor was a question on efficiency of classification included since it was thought that the inclusion of efficiency of dassification in the questionnaire at this preliminary stage might render the forum discussion,. while everybody was trying to find his bearings, too unwieldy. However, it is evident that, as discussions develop, this forum will have to define a uniform method for establishing most efficient classification in grinding circuits

Jan 1, 1957

By He De-wen

Based on the principle of life cycle assessment (LCA), municipal solid waste management (MSWM) was analyzed by life cycle inventory method. According to the system expansion and substitution method, the content and frame of life cycle analysis is summarized and applied to municipal solid waste. On the basic of feasibility research of life cycle analysis on MSWM, the paper put forwards complete and concrete ?three changes? measures under life cycle analysis on MSWM. Some aims of MSWM can be achieved under above conditions of LCA on MSWM: to improve the current system efficiency of MSWM; to enhance the serve quality of MSWM, to increase recycle garbage from MSW; to reduce waste amount and reach minimization and innocuity aim of MSWM; to help the departments of MSWM to get over all difficulties to realize their ideal goals.

Jan 1, 2009

By Leonard Kellogg

Introduction The Mine Manager or Superintendent is a man faced with a difficult problem. He must direct the activities of his mine in such a manner that, over a period of time, the greatest possible profit will be realized. In this respect, a mine is no different from any other business organized for profit. What makes the mine manager's task so difficult then? The profit of a mine is determined by -among other things -the grade of ore, the market price of the metal or metals produced, and the cost to operate the mine. The mine manager cannot do much about the first two of these, but he has considerable control over the operating cost. This cost will depend in large measure on the nature of the programme on which he plans to operate his mine. This operating plan may be broad or specific, on a long-range basis or on a month to month basis. The development of the plan, however, is made very difficult by the existence of so many factors which must be considered. These may be (1) factors requiring decisions based on the best judgment and interpretation of engineering and geological information available, or (2) items which must be considered but which are largely non-controllable. To be more specific, examples of such items would be: (1).-(a) The amount and type of development work to be done in relation to amount of ore to be mined. (b) Mining methods to be followed and type of equipment to be used. © Amount of exploration diamond drilling to be done if the orebody is not clearly defined. (2).-(a) Rock type and degree of hardness. (b) Width, depth, and pitch of veins. © Amount of work requiring timbering. (d) Faults encountered. (e) Water and gas conditions met with.

Jan 1, 1952

By D. R. Tweeton

The U.S. Bureau of Mines has developed tomographic computer programs for geophysical applications and is distributing them as part of a Bureau plan to facilitate the transfer of technology to potential users. These programs were developed for predicting and monitoring the flow pattern of leach solution during in situ mining. The Bureau has also applied them to assessing high-wall blast damage and examining the integrity of mine-related geological structures. This report describes the curved ray program BOMCMTR (Bureau of Mines curved ray tomographic reconstruction), tells how to run it, and gives examples with synthetic and field data. BOMCRATR provides optional mathematical constraints to counteract the nonuniqueness of tomographic reconstructions with crosshole data. These constraints include limiting the maximum and minimum velocities, fixing the velocity at any point to any value, and establishing layers in which velocity does not vary with horizontal position. The user can test for nonuniqueness by varying the initial velocity pattern, The program can perform either curved or straight ray analysis. Ray paths are calculated analytically in triangular pixels, which is faster than incremental numerical approximations,

Jan 1, 2010

By W. E. Roscoe

"Mineral exploration properties are those on which an economically viable mineral deposit has not yet been discovered. Such properties are bought, sold, optioned and joint ventured on the basis of their perceived potential for the existence and discovery of a viable mineral deposit. The intrinsic value of an exploration property is therefore based on the exploration potential. One measure of the exploration potential is the amount that can be justified to spend on exploration for a viable deposit.The appraised value method uses a cost approach to value exploration properties. It is based on the premise that an exploration property is worth the meaningful past exploration expenditures plus warranted future costs to test remaining exploration potential. Results of past exploration work are analyzed in order to retain only those past expenditures that are productive in terms of identifying remaining potential. Warranted future costs comprise a reasonable exploration budget to test that potential."

Jan 1, 2002