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By Office of Public Information

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable.·This issue of the Bureau of Mines. List of Publications and Articles describes reports and articles published during the period January 1, 1985, to December 31, 1989. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3 from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 from January 1, 1975, to December 31, 1979;6 and from January 1, 1980, to December 31, 1984.7"

Jan 1, 1990

By D. D. Eyer

New or improved technology will continue to drive productivity improvements through the next decade. In January 1988, I presented a paper titled, "Large Underground Mines of the 1990s? before the SME. I will follow some of the themes developed in that paper as modified by our experience in the past two years. In order for a coal company to be profitable today, it has had to reduce unit costs experienced in the past. This is because the current average realization, even accounting for a recent strengthening, remains below that of a few years ago. Doing business as was done in the past is not good enough. The coal industry needs to increase productivity in the range of 5-10% annually merely to stay even with rising costs. Underground productivity has been increasing more rapidly than that for surface mining. With the exception of the Powder River basin of Montana and Wyoming, underground productivity has caught up with that for surface mining in many regions of America. There are a number of technological factors which have attributed to increases in underground productivity and which should be factors in the future.

Jan 1, 1990

By N. E. Chaouai, M. Lavigne

"Indicator kriging is one of the non-parametric geostatistical techniques, ideal for estimating the reserves of irregular mineralizations (e.g. gold, uranium, platinum, diamonds, etc.). Such mineralizations are characterized by variograms which are very sensitive to extreme values (outliers) and very difficult to model.The classical approach to this problem in the industry is to trim off these high grades using arbitrary empirical upper limits established either from practice or subjectively. Contrary to this simplistic approach, indicator kriging discretizes the histogram of the grades (usually log normal) in several classes and carries out interpolation separately for each class. This paper gives an overview of the differences between ordinary and indicator kriging along with the steps required to carry out indicator kriging. The paper concludes with a case study involving a gold deposit estimation.IntroductionParametric geostatistics (ordinary kriging) has given us satisfactory results over the years in estimating the reserves of well behaved deposits with coefficients of variation close to 1 (e.g. sedimentary and porphyry type deposits). However, numerous problems have been encountered in estimating irregular mineralizations (e.g. small vein deposits of precious metals) with high coefficients of variation in the range of 2 to 5. Such deposits are characterized by a very small proportion of extreme values (outliers) which create distortions on the variograms (pure nugget effect) and render them useless(1,2).The solution often followed by the mining industry today is to trim off these values based on empirical limits. These limits are derived either by comparison with production results (or bulk samples) or by geological interpretations. Needless to say that such manipulations can lead to serious errors in estimating ore reserves (usually underestimation of total metal quantity), especially when production results or bulk samples are absent.On the other hand, the solution followed by the geostatisticians in the past was to smooth out the data using transforms (e.g. normal-score or natural logarithms). Such transforms are nonlinear and they required non-linear estimation techniques such as disjunctive kriging (DK) or multivariate gaussian kriging (MG) which require normal related hypotheses, not necessarily true in geology.Nonparametric geostatistics (indicator and probability kriging) have been -developed in order to handle these problems related to highly skewed distributions."

Jan 1, 1990

By E. M. De Souza, A. M. Coode

"When Canadian potash was brought into production in the 1960s substantial research was carried out to develop the technology needed to cope with the unique conditions in Saskatchewan mines. The intense research has established Saskatchewan's position as a leader in production technology on a world scale, and as a leader in setting international standards for potash production. The industry is now more than two decades old and, although the mines operate efficiently, there are a number oj prominent areas of concern. High among these is the prediction, prevention and control of sodium rich brine inflows. Control has proven difficult or elusive in the potash mining horizon, but work continues in this area. Control of brine in the superincumbent limestone formation has proven to be easier and more conclusive.The first part of this paper describes the rehabiltation, diamond drilling, and grouting completed at Central Canada Potash, which reduced the brine inflow from approximately 82 l/min . at the beginning of the work to O.9/1min. when the backfilling was placed.The second part of the paper describes the rationale for choosing the rock mechanical instrumentation, the reasons for their placement and the rock mechanical data recorded with some interpretation.IntroductionCentral Canada Potash is located approximately76 km southeast of Saskatoon, near the Yellowhead Highway. The commercial production of potash at CCP started at the end of 1969 at a depth of 1021m below surface. The potash zone, which is presently mined, is approximately 3.35 m thick . Stress relief methods using yielding pillars are used in the design of the mining layouts. The planned extraction ratio averages 35070 . The mine is designed to produce approximately 3.3 million tonnes of sylvinite per year to give approximately 1.3 million tonnes of finished product (muriate of potassium) per year."

Jan 1, 1990

Vaal Reefs Mine annually produces some 75 tonnes of gold. Stoping operations, using a scattered mining method, are conducted on several reef horizons within Witwatersrand Supergroup metasediments of the Klerksdorp Goldfield. Current grades average 7.19 g/t Au over a 133cm stoping width. The reef horizons, of which the Vaal Reef is the most important, consists of 2.9Ga palaeoplacer deposits at the base of low angle unconformities. Typically, a reef comprises a mature quartz and chert conglomerate with a siliceous matrix and intergranular pyrite and carbon. Geologists are primarily responsible for underground mapping and supervising of drilling programs. To a lesser extent they are involved with sampling, grade control, ore reserve estimation, mine planning and rock mechanics. Due to a general decline in grades of gold mines, an escalation of production costs, and with the current weak gold price, it has become essential to improve production efficiencies. Consequently the role of the mine geologist has moved away from that of simply keeping the mining people "on reef'. Greater emphasis is being placed on refining geological models to assist in selective mining of the reef and investigations of secondary reef horizons are encouraged. Exploration within fault losses and re-evaluation of pillars is important, and geologists are becoming more involved with sampling and grade control exercises.

Jan 1, 1990

By W. H. Schiffbauer

The U. S. Bureau of Mines has been investigating methods and technology that, when applied to existing continuous coal mining machines, may improve production and safety. Toward those goals, a microcomputer network has been designed that provides automated control and monitoring of all mining machine systems using a single twisted pair cable (two conductor stranded wire twisted together to provide a level of noise rejection). The network also provides -connections for intelligent sensors and systems for navigation and diagnostics. The flexibility of the network is demonstrated in that features can be added and removed without redesigning the whole system. A general description of the network's integration to a Joy' 16CM, Joy 14CM, Jeffrey 102, and a custom built auger machine is provided. The microcomputer networks for the Joy 16CM and the Jeffrey 102 have been installed onboard the mining machines and have been extensively tested at the Bureau of Mines test facility. The Jeffrey 102 system has also been tested in an actual highwall coal seam. Both systems have performed satisfactorily. The microcomputer networks for the Joy 14CM and the Auger Miner have been tested and await installation on the respective machines.

Jan 1, 1990

By H Hutchinson

Froth flotation is applied to mineral sand concentrates in order to produce commercially viable xenotime concentrates. Experiments indicate that a xenotime product containing 38% Y2O3 at 47% recovery or 34% Y2O3 at 83% recovery can be obtained from a 27% Y2O3 feed. The process involves a primary stage of reverse flotation at which oxide and silicate gangue is floated, and secondary stage of direct flotation at which xenotime is floated. Of the various collectors screened an amphoteric compound was found to be effective at both stages. This was made possible by the addition of sodium silicate at the second stage, which acted as depressant for the remainder of the gangue. Similar studies on a low grade feed material were somewhat unsatisfactory as the grade achieved fell short of what was targeted.

Jan 1, 1990

By Louis J. Sousa

In November 1989, the U.S. Bureau of Mines sponsored a 2-day conference to stimulate thinking and discussion about changing materials technologies and implications for the Government's materials information programs. On the first day of the conference, speakers provided overviews of developments occurring in each of the major materials groups. Emerging technological developments, applications, economic and national defense significance, intermaterial competition, and potential market growth in advanced plastics, polymer composites, ceramics, metals, and electronic materials were described. In general, the speakers forecast advanced materials market growth rates in excess of overall gross national product (GNP) though high costs will tend to limit growth outside of aerospace, defense, electronics, medical equipment, and other typically high value-added businesses. On the second day, a wide range of speakers representing several facets of the materials community described how advances in materials technology are creating a need for new types of data, statistics, information, and analysis. Reflecting the speakers' broad range of organizational, professional, and personal perspectives, an array of information needs was identified. Most requirements, however, seemed to fall into one of five major categories: Federal materials research activities, material standards, market and economic information, health and safety, and public policy.

Jan 1, 1990

In open cut gold mining at Mt Magnet and Reedy, grade control sampling is done with inclined RC drilling using one metre samples. In the small open cuts at Rothsay blasthole sampling was successfully used. Underground sampling for gold and copper grades at Rothsay is done using chip sampling. At the Youanmi open pits both Ditchwitch Earthsawing and RC drilling are used.All assay data are interpreted on sections and plans using a customised SURPAC system. Reconciliations of the grade control predictions of tonnes and grade against initial ore reserves, mining production and milling results are carried out monthly.

Jan 1, 1990

U.S. demand for building and construction materials, such as construction aggregate, gypsum, and cement, remained strong in 1989. Cement imports declined slightly, representing about 17% of apparent consumption compared with 19% in 1988. Mexico, supplying 29% of the total, was the primary source of imports, followed by Canada with 21 %, Japan with 14%, and Spain and Greece with 10% each. Mexico was also the target of an antidumping petition, filed by producers in Arizona, Florida, New Mexico, and Texas, alleging that Mexican cement was being sold in these areas at less than fair value. This was the second petition filed against Mexico in the last 3 years. The International Trade Commission made a preliminary determination that the cement industry in these regions was materially injured by Mexican imports. U.S. demand improved for construction aggregate for the fourth consecutive year and was at a near-record level. The U.S. gypsum industry performed well, even though new housing starts decreased for the third consecutive year. Increased U.S. exports of gypsum wallboard and strength in the remodeling markets offset the impact of declining housing starts.

Jan 1, 1990

By G. Myers, C. J. Wendt, W. H. Wilkinson, M. D. Dennis

Precious metal mineralization at Mt. Hamilton, NV is associated with a polymetallic, garnet-pyroxene skarn system developed in middle to upper Cambrian calcareous shale, limestone, and dolomite. The skarn is developed around the Cretaceous Seligman and Monte Cristo calc-alkaline stocks. Gold is associated with intense retrograde alteration. Later epithermal quartz veins contain gold, silver, base-metal sulfides, and sulfosalts cross-cut skarn alteration. Westmont Mining Inc. is currently developing two mineralized zones containing a geologic resource of about 7 Mt (7.7 million st) that averages 1.7 g/t (0.05 oz per st) gold and 17.2 g/t (0.5 oz per st) silver. The project will have an estimated mine life of seven years, with a planned annual production rate of I t (35,000 oz) of gold and 9.3 t (300,000 oz) of silver.

Jan 1, 1990

By S. Dallaire

"RÉSUMÉLes revêtements céramiques ont une moins grande visibilité que les revêtements métallurgiques. Ils ont cependant jour un role significatif dans noire développement technologique. Les procédés de revêtement ont permis de s'affranchir de barrières technologiques importantes dans le domaine de l'optique, de l'électronique, de l'usure, des hautes temperatures. L'introduction de nouvelles technologies ou la mise en service de nouveaux matériaux peut nécessiter l'adaptation de certain procédés actuels ou le recours a des procédés qui ont peu percé jusqu’ à maintenant.ABSTRACTApplications concerned with ceramic coatings are not as well known as those with metallic coatings. However, ceramic coatings have played a tremendous role in the development of technology. Ceramic coating processes made it possible to overcome technological barriers in the areas of optics, electronics, wear resistance and high temperature applications. Ceramic coatings can provide new properties to materials never considered for demanding applications. They can also open new frontiers and revitalize materials which are maturing or in decline."

Jan 1, 1990

By C T. Hollick

Conventional processing of heavy mineral deposits containing radioactive rare earth minerals such as monazite and xenotime may cause industrial hygiene problems through atmospheric dust and contamination of product concentrates. An alternative procedure has been developed in which such minerals are removed from bulk heavy mineral concentrates by flotation with little loss of other economic minerals. With fine ores, recoveries of over 95 per cent have been achieved and with coarse ores over 80 per cent, in both cases at high grade. Several flotation regimes have proven effective. The potential for generation of radioactive dust or product contamination is subsequent processing is correspondingly reduced.

Jan 1, 1990

Lungfish and crayfish inhabit continental ecosystems similar to those of their ancient counterparts in the Permian (lungfish) and Triassic (crayfish) Periods, exhibiting similar burrowing behaviors to live, breed, and escape desiccation. Identification of their burrows in the geologic record when body fossils are absent has relied on the overall gross morphology of the burrows and the process of elimination. A method of burrow identification has been developed by evaluating burrow structures in an attempt to designate architectural and surficial burrow morphologies that uniquely reflect the distinctive burrowing mechanism of a particular organism. The information from this method defines the burrowing signatures of an organism, enabling the differentiation of their burrows even when fossil evidence is lacking.The lungfish constructed simple, vertical burrows with bulbous terminations. The burrow walls exhibit fine, horizontal to sub-horizontal striae and vertical to sub-vertical striae near the top of the bulbous terminus, reflecting a burrowing style similar to modern burrowing lungfish. The crayfish constructed simple, vertical burrows to complex burrows with multiple branching and chamber development. The burrow surface ornamentations exhibit horizontal to sub-horizontal ridges, vertical to sub-vertical groupings of scratches, mud- and lag-liners, knobby and hummocky textures, and body impressions, which reflect the burrowing mechanism of the crayfish.

Jan 1, 1990

By Kal V. S. Sastry

Modeling and simulation are two major tools available to a mineral process engineer for a consistent and systematic process analysis. The application of these tools to the analysis of specific mineral processing unit operations is well documented in the literature; nevertheless, they are used only to a limited extent in the industry. This is because the fundamental principles of modeling and simulation in the context of mineral processing context are not available. This paper represents the first in a series of papers planned to meet this need. General principles of process modeling and a unified mineral process model development methodology are presented. A simple example of model development using the flotation unit operation is given. A discussion of the practical significance, challenges and opportunities associated with mineral process modeling is included.

Jan 1, 1990

By P. R. A. Andrews, R. K. Collings

The beneficiation of barite has been the subject of many investigations at CANMET, thus reflecting barite's importance as an industrial mineral. Fifty-one studies relating to various aspects of beneficiation were conducted between 1920 and 1986, and a review of some of the more important studies is presented. The information, including mineralogy, beneficiation methods and results, flotation parameters, and reagent concentration data, is presented in tabular form. By so arranging the principal data, the research worker and production metallurgist will be assisted in the evaluation of barite ores from a variety of origins.

Jan 1, 1990

By Smith IEM

Some samples from arc-type volcanic suites collected in northern New Zealand and southeastern Papua New Guinea show rare earth element (REE) and Y abundances which are enriched relative to the those typical of their respective associations. This enrichment appears to be the result of an alteration process which selectively mobilises the REE and re-precipitates them as REE-bearing minerals in veins and interstitial patches. The alteration is on a micron scale and is not detected in routine petrographic examination. The spectre of REE mobility in young apparently fresh rocks is important to igneous geochemists who use REE abundances to constrain petrogenetic models and may also be important because it indicates the operation of a natural REE enrichment process which could operate in the formation of economic REE deposits.

Jan 1, 1990

By D. R. Zhu, H. S. Chiang, Y. M. Jiang, S. S. Peng

Two types of underground tests on three types of shield supports, 2-leg, 4-leg, and chock shield, were con- ducted to measure the horizontal movement of the canopy against the immediate roof. In no friction tests, steel rollers were placed between roof and canopy top, while in friction tests normal direct contact was used. Results indicate that the canopy for 2-leg shields always moves forward during setting, whereas there was no forward movement for 4-leg or chock shields. Based on the test results, a model for active horizontal force was proposed.

Jan 1, 1990

An integrated computer system (the Short Term Mine Management System) has recently been developed by B.H.P. Steel Long Products Division in Whyalla, South Australia for use in their open pit iron ore mines.The system incorporates blast design, comprehensive blasthole data handling, grade coilrol, stockpile scheduling and management and reconciliation within a single, user friendly computer package. The blast design system allows the blasting engineer to design the layout of holes for a production blast using geological information projected from the bench above to aid in appropriate blasthole positioniog in particular rock types. The grade control system allows mining blocks to be designed and evaluated from blasthole information using interactive graphics processes. The handling, storage and reporting of blasthole survey, assay and geological logging data forms an integral part of this system. Stockpiles can be constructed from a number of mining blocks to reach a specified target grade using the stockpile management system. Although not yet integrated, the reconciliation system will reconcile stockpiles back to mining blocks and to the geological model.

Jan 1, 1990

By Christopher Mark

The past decade has provided a wealth of practical experience with longwall pillar design. Design formulas developed specifically for longwalls have proven their value in numerous applications. Analytic methods, including numerical models, have a1 so made important contributions. These advances have been based on basic research into abutment loads, coal pillar mechanics, and the interaction between pillar performance and entry stability. The goal of this paper is to review the state of the art in longwall pillar design from the standpoint of the practitioner. Actual case histories are presented to illustrate the current capabilities and limitations of pillar design methods. The paper also discusses the advances that can be expected in the future.

Jan 1, 1990