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By Chas. F. Jackson

The annual reports of the supervising engineers of the nine sections comprising the Mining Division are assembled here and constitute the annual report of the division. In planning activities the aim is to adapt them to changes in conditions, in the needs of the mining industries, and in the public interest; those that contribute most to solving the present problems are emphasized, investigations of less immediate importance being recessed if necessary. The strategic minerals investigations of the bureau afford an example of this change in emphasis to problems of immediate and urgent interest, and during 1941 they comprised, upon the basis of appropriations and expenditures, more than 90 percent of the work of the division.

Jan 1, 1941

The Macraes Mining Company Limited was listed on the New Zealand and Australian stock exchanges in January 1990, and the proceeds of the float were used to purchase a 70 per cent interest in the Macraes Gold Project, previously owned by BHP Gold Mines (NZ) Limited. Macraes Mining has had a 30 per cent interest in the project since May 1984, when it was incorporated. Project financing in the way of a gold loan was secured in February 1990 and construction commenced shortly afterwards. The mine construction activities were completed within nine months and the mine commenced operations in October 1990.

Jan 1, 1991

By A. C. Johnson

The Bureau of Mines explored the Three Kids deposit in 1941 as part of a strategic minerals program. Earlier mining and exploration had established the presence of a substantial tonnage of medium-grade wad ore, and drilling and sampling by the Bureau of Mines, in collaboration with the Federal Geological Survey, indicated an additional tonnage such that development and exploitation became more clearly feasible. Private interests, with Government support, undertook to produce metallurgical-grade manganese. The present paper describes the Bureau of Mines exploration and subsequent development. Manganese in the Three Kids area is found in one of the lower members of the Muddy Creek formation in a bed of fine sandstone and silt, which outcrops around the north edge of the River Mountains and generally dips 20° to 40° away from the hills. There is considerable variation in the thickness and grade of the ore. The ore is light weight, having a density of 1.2 to 2.

Jan 1, 1956

By Michael J. Jorgensen, Pranathi B. Aedla, N. K. Kittusamy

Risk factors associated with the development of muscu­loskeletal discomfort and disorders during the operation of heavy mobile equipment include whole-body vibration and awkward and sustained joint postures of the shoulders, neck, and trunk. Cab design may influence awkward postures of the joints, and task duration may influence duration of exposure to awkward and static postures and whole-body vibration. To reduce exposure to risk factors related to the interface between cab design and task, it may be necessary for manufacturers to address cab design. This study assessed the repeatability of a cab design checklist developed to evaluate various design characteristics that can influence exposure to risk factors for musculoskeletal discomfort. The ability of the cab design checklist to identify posture-related deficiencies of design was also assessed. The checklist was used by two administrators across 10 pieces of heavy construction equipment. Video analysis was performed to quantify postures of the neck, shoulder, and trunk; correlation analysis was used to determine whether specific questions from the checklist were associated with the identification of awkward postures. The repeatability assessment resulted in kappa coefficients ranging from 0.52 to 1.0 (good-to-excellent reproducibility) across each piece of equipment, and an overall kappa coefficient of 0.77 (excellent reproducibility) when considering all equipment together. Results from the correlation analysis showed that shoulder flexion posture was correlated with scores from the cab design checklist. However, results of the cab design checklist were not significantly correlated with shoulder abduction or awkward postures of the neck and trunk. Results suggest that the cab design checklist may be useful for identifying cab design characteristics that need further improvement and for identifying design characteristics that increase shoulder flexion. The strength of the repeatability assessment suggests that outcomes of the cab design checklist administered by different individuals may be consistent, independent of the type of equipment being assessed.

The New South Wales coal industry is a highly mechanised well organised industry which has developed from an annual production of slightly less than 13 million tons in 1950 to over 33 million tons in 1969. Although continuous miners were not introduced into the mines until 1950, by Jillle 1969 the percentage of coal won by these units was 87.3. The paper describes mining conditions in the various coalfields of the State, their complexities and problems and how these have been dealt with. The introduction of fully mechanised long wall faces has presented a challenge which has been accepted and descriptions of systems in use are discussed. Major expansion of the industry is anticipated to meet the requirements of the growing Australian steel industry, for local power generation and to meet the increasing demands of overseas markets.

Jan 1, 1971

Acoustic Emission Monitoring of Froth Flotation

Sep 13, 2010

A pilot program was undertaken to evaluate a process developed by the U.S. Bureau of Mines to recover nickel, cobalt, copper and chromite from domestic nickel laterite resources. An existing five ton per day pilot plant was modified to accommodate treatment of laterite by the Bureau process, which employs reductive roasting, ammoniacal sulfate leaching, solvent extraction, and electrowinning to extract, separate, and recover nickel, cobalt and copper as high purity cathode products. Three distinct types of laterite i.e., limonite, saprolite and a mixture of limonite/saprolite were processed through the plant during three operating campaigns. Nickel cathode was made during all three campaigns, while cobalt cathode and chromite concentrate were recovered only during processing of limonite. Leach extraction of nickel and cobalt averaged 83 and 67 percent, respectively, while the overall recovery was 80 and 63 percent for nickel and cobalt, respectively. Initially, over-reduction of iron in the saprolitic calcine contributed to poor settling of the leached solids. This problem was overcome by careful control of reducing conditions and flocculant addition. An economic feasibility study was made for a 5000 TPD grassroots laterite processing facility scaled-up from pilot plant data. Estimated (+ 30) percent capital cost for a Nine and plant is $367 million with an estimated $103 million per year operating cost. The study indicates that low-grade domestic laterite may he processed with marginal profit- ability.

Jan 1, 1982

In order to ensure safe mining and reduce surface damage in shallow multiple-seam mining, the failure characteristics of interburden strata with different coal pillar offset distances between pillars in the upper and lower seams, the distribution characteristics of stress concentration in coal pillars, and the development characteristics of stratum cracks and subsidence were physically investigated and also using UDEC2D software. Meanwhile, the effect of different coal pillar offset distances on the stress concentration of coal pillars and development of stratum cracks were studied. Based on those results, a formula for safe mining and reducing surface damage was established, which provided a theoretical basis for safe and environmentally friendly mining in shallow multi-seams. According to the results of the study, the optimal coal pillar offset distance (the side-to-side horizontal distance of the upper and lower coal pillars) between the upper and lower coal seams was developed to reduce the stress concentration of coal pillars and surface damage. The results of this study have been applied in Ningtiaota coal mine and have achieved good results in safe and environmentally friendly mining.

Jul 28, 2020

By W. H. Goghill

Numerous investigators have studied grinding. Each has contributed his bit to a literature that is difficult to correlate. Too many of the results have been transformed into curves with so many "inflection points" and "counterflexures" that they obscure the issue. Some of the investigators have neglected the very essence of the problem, namely the power and the amount of material to which a known amount of work was applied. The purpose of this paper is to show the ease with which results can be interpreted when these quantities are duly recognized. Some grinding tests will be given for illustration. Grinding studies are of two kinds: (1) Study of the character of the ore and (2) study of the performance of the machines. Several ores may be crushed by a given machine, or several machines may be used on a given ore. The illustrations given in this report cover both objectives.

Jan 1, 1934

By Siavoljub D. Maksimovic

The Bureau of Mines, through a cooperative agreement with Duquesne Light Co. of Pennsylvania, field tested a method of using pneumatic stowing of crushed limestone to construct seals in long-abandoned mine openings that were part of an active mine closed shortly before sealing. A total of 13 openings at 11 sites were backfilled. In pneumatic stowing, material is conveyed through a pipeline and into the mine opening under low air pressure. The stowing equipment consists of a power sup-ply, a blower, a feeder to inject material into the pipeline, and a nozzle for directing the placement. Material is ejected from the nozzle at high velocity, creating a high-compaction fill upon impact. The fill material used was well-graded limestone aggregate up to 1-1/2 inches in diameter, with sufficient fines. This fill was modified at five locations by the addition of portland cement, expansive cement, and/or bentonite. The pneumatic stowing method is safer and faster than conventional methods, is cost competitive, and eliminates or reduces the exposure of workers to possible hazards since the nozzle can be kept outside the mine opening. The equipment is mobile, but some modifications in the technique would improve performance. The technique was used at remote locations where other methods could not be used without disturbing the environment.

Jan 1, 1982

By W. W. Culver

The paper explores the substance, circumstances and significance of the Whelpley and Storer Copper Process. The 1866 Whelpley and Storer patent specified a process combining mechanical and chemical engineering. The process called for a down-drafting shaft furnace with a horizontal flue connected at the bottom of the shaft. Powdered sulphide ore was roasted in the shaft and then sent forward fully oxidized to a bath of sulphuric acid and/or calcium chloride. The “water furnace” was developed in Boston, at a time when the city was home to most Michigan copper mining companies. The process was field-tested at Quebec’s Harvey Hill copper mine. In 1865 James Douglas, Jr. took over management of the Harvey Hill mine with the challenge of saving the family investment. He needed a way to make money from low-grade sulphides. Through his relationship with chemist T. Sterry Hunt, Douglas learned of a possible way ahead using the process developed by Whelpley and Storer. The paper confirms the centrality of publications, meetings, and networking in the advancement of metallurgy. The process is of interest historically, as much as anything, because it is one of the pillars of James Douglas’ distinguished career in copper. INTRODUCTION At the 1866 meeting of the American Association for the Advancement of Science (AAAS) in Buffalo, New York, T. Sterry Hunt (1826–1892) read a paper “On the Metallurgical System of Messrs. Whelpley and Storer.” The paper is part of a chain of events that constitute the foundation of James Douglas’ (1837–1918) success in the copper mining industry. To understand the career of Douglas over the early years of modern copper mining, we must necessarily start with Whelpley and Storer. Going back to Hunt’s paper, he concluded his remarks by asserting that the Whelpley and Storer Process was “capable of such wide and varied application, that it is probably destined to have a very important influence on the industry of the world” (Hunt, 1867a). He reached this conclusion reasoning that the process had overcome a critical metallurgical hurdle (Hunt, 1867a). Hunt, a geo-chemist in modern terms, recalled that the chemist of those years easily separated copper from “sulphuretted” ores by converting it to a soluble salt from which pure metal was precipitated by “an equivalent of iron.” The problem was to “…apply this principle in the working of copper ores on a great scale...” (Hunt, 1867a). Hunt noted that this very problem had “…engaged the attention of many metallurgists, and has given rise to various processes for obtaining copper by the moist way, many of which are nearly or quite perfect in their operation, but are lacking in practicability and cheapness” (Hunt, 1867a). Hunt thought Whelpley and Storer had overcome the low-grade sulphide hurdle with a commercially viable engineering breakthrough. Yet in the history of copper metallurgy, the process is missing. What happened?

Jan 1, 2019

By R. Schuhmann

Jan 1, 1965

By A. Nivala, S. Ulgiati, M. Canino

Mining and processing of bastnaesite ore, (Ln)CO3F, for lanthanides extraction is investigated in this paper. This series of elements proved to be applicable for a wide range of high-tech uses. In spite of the strategic importance of lanthanides, no LCA and energy analyses of their extraction have ever been published. We perform in this paper a Life Cycle Assessment of the Lanthanide production cycle, based on available database and literature data from Mountain Pass mine (USA) and other worldwide mining and processing sites, most of which in China. We investigated three main steps: mining, milling (including transport, grinding and drying), and flotation (for lanthanide chloride extraction). We do not investigate here the separation of pure oxides from lanthanide chloride, a compound which is also marketed as such. The conventional LCA was integrated by means of energy and emergy evaluations, aimed at investigating respectively the global energy cost and the environmental sustainability of the process. Indicators of material intensity, thermodynamic efficiency, and environmental impact (including LCA and ecological footprint impact categories) are calculated and discussed.

Jan 1, 2005

By A Giblett, K Afewu

This paper uses a case study to demonstrate best practices techniques for predicting the contribution of gravity concentration in a gold recovery process flowsheet. The case study was selected as an example of an ore with a marginal gravity gold content, which makes the value of a gravity circuit difficult to quantify. In this instance the value of leveraging a significant knowledgebase of operating gravity circuit performance to support the decision making process was demonstrated. This case study analysis serves as a useful demonstration of best practice methodologies supporting decisions to include or exclude gravity recovery in a gold recovery process flowsheet.CITATION:Giblett, A and Afewu, K, 2015. Do we need a gravity circuit or not? A case study in applying best practice, in Proceedings MetPlant 2015, pp 288–295 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

The minerals industry consumes billions of dollars in raw materials, equipment, tools, services and chemicals. The industry, though, has turned overmuch of the research and development (R&D) for these products to manufacturers and suppliers. Now the industry and its suppliers must decide how much R&D the mining industry should be responsible for and what role the suppliers should play. Promoting R&D As a result of the current environment in the mining and minerals industry, there has been a substantial decrease in R&D. Depressed prices, stagnant growth, cost cutting and rationalization are evident.

Jan 1, 2000

By Wils L. Cooley

Although electric utility companies have been active in grounding and bonding within substations, the mining engineer or mine electrical engineer is not involved to the extent that he can be fully up-to-date on the most effective practices for substation construction. The coal mine power system is grounded in a fundamentally different way from most other industrial power systems and is subject to considerable Federal and State regulation. At this time, there is little information that is directly applicable to the mine situation, especially if the substation must be built in an area of limited size or in low-conductivity earth. The objective of this guide is to provide specific engineering information to the mining; industry. Using as little theory as possible, it was written to be general enough to cover most substations, but specific enough to provide direct help with each substation. It will attempt to recommend practice that is in agreement with present Federal rules and regulations.

Jan 1, 1980

By John C. Machisak

THIS PUBLICATION presents injury experience and employment data for the nonmetal mining industry in the United States for 1960. Data for the mines and mills are presented separately, as shown in the list of tables. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry for their voluntary submission of injury and employment data. As the information submitted contributes largely to the promotion of safety in the industry, special effort has been made to ma e these questionnaires as complete as possible.

Jan 1, 1963

By C. Musingwini

The subject of optimal planning of level and raise spacing for inclined narrow reef deposits has received intermittent attention over the years because the subject matter is inherently complex. Previous work has approached the problem as simply that of simultaneously minimizing the total excavation and haulage cost associated with the development workings. However, when level and raise spacing are altered, other factors such as productivity are negatively affected, thus requiring a delicate trade-off of contradicting planning or optimization criteria. The paper concludes that the problem is actually of the multi-criteria decision analysis (MCDA) type, contrary to traditional thinking that the planning problem is achieved solely by minimizing waste development.

Jan 1, 2010

By M. Leroux, S. R. Rao, J. A. Finch

"Poor Pb-Zn selectivity during Pb flotation in laboratory tests on a Mississippi Valley-type Pb-Zn ore was traced to apH effect. In the pH range, 9.5 to 11.0 sphalerite floated readily without copper activation. Compared to sphalerite flotation with copper activation this procedure gave equivalent selectivity but reduced flotation rate.Possible mechanisms of this sphalerite flotation without copper activation are discussed. Activation by Fe(OH)2 is suggested, the Fe- + ions being derived from superficial oxidation of pyrite in the ore. IntroductionGalena and sphalerite commonly occur together. A typical procedure, using xanthate collectors, is to float the galena first, at pH - 8, followed by flotation of sphalerite after activation with copper (II) sulphate at pH - 10 (to depress pyrite).Flotation tests following this procedure in an undergraduate laboratory course with a Pb-Zn ore from Polaris failed to achieve consistent selective flotation of galena. Occasionally a considerable amount of sphalerite, even though unactivated with CUSO4, floated. This was traced to accidentally high pH. A systematic study was carried out which revealed that sphalerite floated readily in the pH range 9.5 to 11.0 without activation by CuSO4 This paper describes the results of the study and discusses a possible mechanism of this flotation of sphalerite."

Jan 1, 1987

By Anthony J. Konya

"This paper was written during part of the author’s student co-op with Cargill Salt at its Avery Islandunderground salt mine in Louisiana. Blasting salt is a unique type of blasting that is different than blasting other rock types. The plastic nature of salt, along with its large swell factor make salt a challenge to blast. The Cargill salt mines use and have tested a variety of different methods for breaking salt in an efficient manner, however these blasting methods are rarely used in other operations nor talked about today."

Jan 1, 2016