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By J. D. Miller

The fossil resins of certain western coals are of significance and of sufficient value as a chemical commodity to justify a fossil resin industry. At the present time these valuable fossil resin resources, worth more than $0.50/lb as a chemical commodity, are being burned as fuel for electric power generation. This waste of our fossil resin resources corresponds to a loss in revenue of $200 million per year -equivalent to the value of the coal itself! Improved process technology for the recovery of fossil resin is under development and includes selective flotation of fossil resin from fine coal streams and solvent refining of the fossil resin flotation concentrate to produce a premium resin product. The most recent developments in process technologies are discussed with respect to separation efficiency and product quality. It is clear that the development of a fossil resin industry should not be limited by process technology.

Jan 1, 1994

By Fathi Habashi

OXIDE ORES can be divided into two groups: 1) Simple oxides (Table 3.1). 2) Complex oxides. Those ores containing minerals composed of two oxides; an acid oxide (Cr2O3, Nb2O5, etc.), and a basic oxide (CaO, FeO, MnO), as shown in Table 3.2.

Jan 1, 1970

By F. B. Brost

In 1976, a decision was made by Anamax Mining Company to install an unusual conveying system to transport ore 10.3 km (6.4 mi) from the new Eisenhower Mine to the Twin Buttes concentrator. The system, supplied by Cable Belt Limited of the United Kingdom, represents a radical departure from conventional belt conveyors. The driving tension is applied through two endless wire ropes driven by a single 2 240 kw (3 000 HP) drive while the belt acts only as the ore carrying medium. Full production was begun in January, 1979. Start-up problems hampered production for several months but were resolved by a joint Anamax-Cable Belt effort. The system has been operating at design capacity for 4-1/2 years, and has proven itself as a reliable, low cost ore transportation system.

Jan 1, 1984

By M. Ghiani

Biohydrometallurgy originated, some forty years ago, from an environmental problem, namely the serious pollution of the Ohio river by acid drainage water coming from neighboring subbituminous coal mines. Studies aimed at elucidating the cause of the intensive oxidation of the iron sulfide (pyrite) inclusions of those coals, led to the discovery of a bacterium, Thiobacillus ferrooxidans (Temple and Colmer, 1951), capable of acting as a catalyzer, accelerating the otherwise very slow chemical oxidation of iron sulfide to rates many orders of magnitude higher. However, it is now recognized that the biotechnology of microbial mining dates back to 1963, when the ability of this bacterium to solubilize copper from sulfide ores was ascertained (Razzell and Trussell, 1963). Much research has been carried out on biohydrometallurgy over these last 25 years and is still being actively conducted all over the world. The interdisciplinary nature of this young branch of science and technology is reflected by the variety of experts involved: microbiologists, mining engineers, hydrometallurgists, physico-chemists, mineralogists, solid-state physicists and biochemists. This intensive research effort has provided a solid background on the fundamentals of this technology, although many important issues have still to be solved, amongst which the enzymatic mechanisms controlling biocatalysis of mineral sulfides dissolution, the influence of bulk- and surface solid-state physics of metal sulfides on dissolution mechanisms, the interaction of the various strains composing natural microbial floras. Their elucidation should permit the rationalization of biohydrometallurgical techniques and the optimization of commercial processes. Biohydrometallurgy has already achieved satisfactory results: copper recovery from submarginal copper sulfide run-of-mine ores (i.e. assaying less than 0.3% Cu) by in-situ, dump and/or heap leaching is successfully practised in many countries and uranium recovery through bioleaching is competitive with other leaching processes.

Jan 1, 1987

By Justin R. Patts, Andrew B. Cecala, A. KYLE LOUK, Emily J. Haas

The National Institute for Occupational Safety and Health (NIOSH) and the former U.S. Bureau ofMines (USBM) have given a significant effort over the past four decades in researching and developing engineering controls and interventions to reduce mine workers’ dust exposures during the bagging and palletizing of industrial minerals. Workers performing manual bagging and palletizing of 50- to 100-pound bags typically have some of the highest dust exposures of all workers at mining and mineral processing operations. This paper will provide an overview of available dust control technologies for bagging operations and present the findings of a recent case study that was conducted at four different industrial sand operations to identify the current types of bagging and palletizing technologies being used and to evaluate their effectiveness in reducing workers’ exposures to respirable crystalline silica dust. An evaluation will also be performed to determine if further reductions in respirable dust levels can be achieved by incorporating additional modifications or improvements into the existing technology.

Apr 3, 2020

By N. Choi, W. D. Cho

Distribution coefficients of gold and silver between matte and slag during the pyrometallurgical treatment of nickel-copper sulfide concentrates were evaluated as a function of matte and slag compositions in the temperature range of 1,250oC to 1,300oC. It was observed that the composition of the matte phase, including matte grade and copper content in the matte, significantly affected the distribution behavior of gold and silver in the matte-slag system. Both gold and silver preferentially concentrated in the matte phase as the matte grade increased With increasing temperature and copper content in the matte, the distribution coefficients of silver increased, while the gold distribution coefficients decreased. It was also, found that slag additives such as CaO, MgO, and A12O3 caused a significant decrease in the solubility of both gold and silver in silica-saturated iron silicate slag. An activity coefficient of gold in matte was derived from the experimenta1 results.

Jan 1, 1999

By Walter C. Labys

This paper reports on recent modeling efforts to analyze the eastern U.S. steam coal market with a cross-sectional econometric as well as a quadratic programming approach. The background to coal modeling is examined first. The particular aspect of the steam coal market to be modeled are then presented and the corresponding coal model described. Both empirical results and rigorous mathematic pertubation analysis are presented. Conclusions are then drawn regarding potential modeling applications in the policy area.

Jan 1, 1979

By Thomas P. Meloy

Comminution is an old art. Unfortunately the analysis of the unit operations has been handicapped by the lack of both theoretical and experimental information. Two types of infor¬mation are needed, one an understanding of what happens when a particle breaks in a brittle manner; and two, an understanding of what happens when the daughter fragments pass through the mill. This paper is concerned with the former, the catastrophic fracture of a brittle solid. Recently, successful theoretical attacks on the frac¬ture of brittle solids have yielded significant-results. New experimental techniques are yielding insight into the physical phenomenon occurring during brittle fracture. Many of the re¬doubtable shiboliths of the last century are either being laid to rest or verified.

Jan 1, 1965

By Ted H. Eyde

Improving the mineral industry's tarnished image describes in a nut- shell the reason why the Speakers Bureau of the Tucson Subsection of the AIME was formed. Let's go back in time about 3 years to the fall of 1971. Literally thousands of bills detrimental to the mineral industry were being introduced into Congress and State Legislatures. Unfortunately, many were being passed and signed into law. Clean air and water, zero pollution, preserve the environment, ecology, biodegradeable, wilderness were the words that the self- styled ecologists and environmentalists were preaching. The mineral industry either sat mute or in place of acting, reacted in a way certain to attract a maximum amount of bad publicity with a minimum amount of rhetoric. A mining company president, for example, commenting on the primary air standards in Arizona was reported by the press as having said, "we'll shut all the smelters down and put thousands of Arizonans out of work if we have to meet the Arizona standards." Or another defending a poorly planned highly visible open pit nonmetallics operation, "we'll take the whole mountain down if we want to, and nobody can stop us" and still another manager of Operations, "the bottom line is all that counts, to hell with all of this environmental nonsense."

Jan 1, 1975

By Jim Gebhardt

Douglas W. Fuerstenau (DWF) grew up on a farm and in several small communities in rural South Dakota during the depression years, where he learned the value of hard work. Working hard can produce results but being clever and hardworking will give you a bright future. In his later school years, Fuerstenau’s family moved to Rapid City where his intellectual curiosity and capacity helped him graduate with a B.S. in Metallurgical Engineering from the South Dakota School of Mines and Technology in 1949. His technical interests led to graduate studies and completion of a master’s degree from the Montana School of Mines in 1950 and Sc.D. degree from the Massachusetts Institute of Technology (MIT) in 1953.

By K. B. C. Brady, B. E. Scheetz, J. E. Cuddeback, T. W. Bergstresser, W. A. Telliard, S. C. Parsons, R. J. Hornberger

Two weathering procedures are being developed by the Acid Drainage Technology Initiative in cooperation with federal agencies(OSM and EPA). Objects are to: (1) standardize existing humidity cell and leaching column procedures; (2) improve test methods by maintaining a carbon dioxide enriched environment needed to optimize carbonate mineral dissolution, and quantifying particle size variables to evaluate reaction kinetics, and (3) provide flexibility in test method implementation consistent with EPA guidelines for Performance-Based Measurement Systems. Preliminary results indicate the CO2enriched leaching environments produce alkalinities that are similar to field observations and greater than the tests run under atmospheric PCO2. Leaching columns produce higher alkalinity than humidity cells.

Jan 1, 2003

By Michael J. Shulman

During-all phases of exploration limited resources must be allocated among exploration methods and among exploration prospects. This problem,, an exercise in optimization, can be treated mathematically. For three objective functions - maximizing return, return to cost and return minus weighted cost - theoretical results exist which enable the exploration planner not only to gain valuable insight into the problem, but also to estimate the resources necessary and to allocate these resources for' at least-two stages of exploration prior to initial field work. A two-stage exploration strategy for volcanogenic-sedimentary iron in northern Egypt illustrates, how the results can be used. Stage 1 consists of an aeromagnetic survey to map the structure of five areas;" stage 2 consists of field reconnaissance work. For the three objectives, lower bounds are calculated as a function of exploration expenditures for each stage in order to facilitate the choice of an-optimal exploration budget. Nomograms are then presented which, based on the Kuhn-Tucker Conditions', enable the incremental allocation of airborne and reconnaissance effort among the five areas.

Jan 1, 1989

By Jose M. Milian, Raphael F. Matson

An intensive study was started in 1968 to determine the most economical process for winning nickel and cobalt from an extensive de- posit of complex, low grade nickel-cobalt ore (1.6% Ni, 0.10% CO) designated "the Greenvale ore." In 1974 the commercial plant at Yabulu, in Queensland, Australia, began processing the ore. In the interim, a great deal of laboratory and pilot-plant effort was applied to develop technical, process and commercial design data to demonstrate to potential financial backers and customers that a full-scale plant was feasible. The laboratory test work, pilot plant facilities and pro- gram are briefly reviewed in this paper.

Jan 1, 1979

By Charles A. Ramsey, Kathleen S. Smith, Philip L. Hageman

We developed a statistically based strategy for sampling the surficial material of mine-waste dumps for use in screening and prioritizing historic dumps on abandoned mine lands. This sampling strategy entails the collection of a representative composite sample from individual dumps and allows for regional or watershed-based assessments. One 30-inment dump-composite sample collected using this sampling strategy contains as much information, relative to average value, as 30 individual grab samples at 1/30 of the analytical cost.

Jan 1, 2000

By G. G. O. O. Uwadiale, M. A. Kollere, M. A. U. Nwoke

Birnin Gwari and Alawa graphite deposits were upgraded by flotation. Using 0.5 kg/t kerosene and 0.25 kg/t sodium silicate, flotation concentrates grading 90.7% and 88% Cg with recoveries of 86.2% and 84% were produced from Birnin Gwari and Alawa graphite samples, respectively. The combination of 0.5 kg/t kerosene, 0.2 kg/t pine oil and 0.25 kg/t sodium silicate yielded high-grade graphite (92.3% Cg) with a recovery of 83.9%. Flotation with refined rubber nut oil and kerosene, at a 1:1 ratio, produced a concentrate grade of 86.3% Cg with a recovery of 90.4%. With acid leaching of the flotation concentrate, a high-grade graphite concentrate containing 98% Cg was produced.

Jan 1, 1998

By Joel Nonnweiler, David Young, John Hawley

The Sacramento Regional County Sanitation District has implemented a billion-dollar interceptor system master plan, including the 31 km (19 mile) long Lower Northwest Interceptor (LNWI). For the two LNWI Sacramento River crossings, pipe-jack/micro tunnel drives in excess of 300 meters (1,000 ft) from 30 meter (100 ft) deep shafts in mixed soil conditions below the water table were considered, as were600 meter (2,000 ft) tunnel drives utilizing pressurized-face tunnel boring machines. Operation and maintenance concerns, predicted flood scour, and levee concerns are discussed. A risk assessment process was used to select both profile and construction method. Construction will begin in mid 2004.

Jan 1, 2003

By H. A. Stoess

The Minerals Industry makes heavy demands for and on its Material Handling equipment. It also gives progressive management the opportunity for considerable savings, ad consequently increased profits. In some cases, cost of Materials Handling amounts to 40°/o of the total cost of the ultimate product. Handling costs are hidden in overhead, indirect labor, excessive maintenance, productive workers performing handling tasks, and, a great many more. Even though Materials Handling is the oldest occupation of mankind, it is only within the past twenty years that it has emerged as a specialized field. While this industry has made full use of all types of mechanical and vibratory conveyors, pneumatic conveyors in their proper application can be a distinct asset. me use of pneumatic conveyors by this industry however is limited- to a certain extent by the particle size of your products through the various phases of manufacture, as well as their bulk density. However, with increasing knowledge of the fluidization of dry materials, their use is becoming more wide spread.

Jan 1, 1962

By Ian Graham

In 2013 the Government of New Zealand launched a number of ‘National Science Challenges’ (NSC) to address major issues facing the nation, and raise public consciousness about science and its role in promoting evidence-based decision making. One of the 10 proposed NSCs focuses on New Zealand’s extensive Exclusive Economic Zone (EEZ) and Extended Continental Shelf (ECS)1, with an objective to enhance utilisation of marine resources within environmental and biological constraints, and the desired outcome of:

Sep 1, 2014

By Y. H. Kim

A simulation procedure has been developed that realistically portrays aggregate growth and disintegration for particular types of floc structures in water and wastewater treatment processes. The procedure requires local dissipation rates and specification of an interaction distance between colliding particles. A principal difficulty encountered in polymer flocculation, however, arises from changes in conformation of adsorbed macromolecules. Therefore, in systems where polymer flocculation occurs by bridging, dynamic changes in the particle size distribution depend upon the interaction of nonlinear. stochastic hydrodynamics with particles whose growth results from a number of concurrent and sequential random processes.

Jan 1, 1988

By Charles B. Dugger

Sacrificial linings for grinding mills have been a necessary state of the art of mineral dressing since the inception of comminution. Long recognized as the final link in energy transmission from power line to ore, mill liners as a scientific endeavor have not expanded as rapidly as other branches of mineral dressing engineering. Several reasons for this technological lag are apparent. Typically in the past, labor intensive foundries were freely located geographically, at a time when transportation charges made up a significant portion of the casting cost. Alloying agents had not gained their current level of sophistication and were relatively inexpensive in the quantities required. Precise foundry controls were not economically justified, or totally understood. Coincidental to these elements, liner consumption per unit processed did not categorically contribute as a major cost item to the mill operator. Grinding equipment was small, and many times lining life exceeded that of the promoter. These unique conditions no longer exist. Ore dressing equipment has grown to meet modern mining demands. Larger processing facilities, utilizing fewer pieces of equipment, have replaced operations of the past. Emphasis today and tomorrow is on larger and larger equipment, with an eye on lower and lower unit processing costs.

Jan 1, 1979