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By Chauncey L. Berrien

The United Verde Copper Company's mine is at Jerome, Ariz. The orebodies arc of the schist replacement type, the main sulfide mass being a large lens-shaped body approximately 7 acres in cross-sectional area. In general, the mineralization is found along the iron schist contact, with the orebodies extending about 1000 ft. along this contact and varying from a few feet to 250 ft. in width. Three types of ore are mined; schist porphyry and the so-called "heavy" or "massive sulfide" ore. Approximately 50 per cent. of the total tonnage mined at present is of the latter class. A representative analysis of this ore indicates 42 to 46 per cent. sulfur. Because of the high sulfur content, blasting in this ore is an extremely hazardous operation. not only does it endanger the lives of men who may be in the mine at blasting time but it also becomes a potential fire menace when timber is in close proximity to shots being fired in these massive sulfides. The origin of the fires of 38 years ago, embers of which are glowing to this day, may perhaps be attributed to dust explosions due to blasting in the massive sulfides of those early square-set stopes. Dust Explosions Dust explosions in coal mines are a common source of mine disasters. That such explosions may be of common occurrence in metal mines is not generally known, but it is known that metal-mine dust will explode and such explosions have been investigated by the U. S. Bureau of Mines at the Pittsburgh Experiment Station. Samples of "heavy sulfide" ore from the United Verde mine were used in the tests. After studying the results of the tests it was concluded1 that: 1. Dust explosions were initiated in sulfide ore dust in the gallery with a charge of as low as 75 g. of 60 per cent. gelatin dynamite. 2. The exploding dust generated considerable pressure.

Jan 1, 1930

By Laxman M. Amaratunga, Glen G. Hein

"Most mining operations utilize the tailings coarse fraction for backfilling while the fines have been traditionally disposed on surface in tailings ponds. Recently, paste fill has been developed which uses a fraction of the fine tailings (10-30% w/w of <45 µm) in the fill (Brummer and Moss, 1991). This development allows a mining company to use a portion of the fines for backfill, but still requires surface impoundment of the unused tailings. Reactive tailings have the added problem of generating acid after being oxidized in the presence of air and water. Treating acid mine drainage (AMO) from these ponds has proven to be a costly environmental problem and a long term liability.One practical method to reduce the environmental impacts associated with the tailings pond is to modify the physical and chemical prope1ties of the fine tailings so that they can be utilized in an environmentally safe manner. This was accomplished by agglomerating the tailings into pellets and using theses pellets as a coarse aggregate in a total tailings paste fill. This technology does not require any supplemental sand or gravel to be added to the fill.This paper presents the ongoing research into utilizing these tailings agglomerates as a coarse aggregate fraction, in order to create a total tailings paste fill which has supe1ior strength characteristics.IntroductionThe Canadian mining industry produces more than 500 million tonnes of tailings and waste rock annually. The waste rock is usually returned underground for use as rock fill in underground support with the tailings remaining to be disposed of in tailings ponds. Tailings consist of a coarse and fine fraction, and can be either reactive (acid generating) or non-reactive. In an effort to minimize tailings disposal, the coarse fraction has been used underground in backfill along with alluvial sands. This diversion of the coarse fraction, however still requires that the fine fraction be disposed of in tailings ponds. This disposal creates the potential for acid mine drainage (AMO), since in the presence of air and water, reactive sulphide tailings can generate acid. It is therefore an important goal in the mining industry to minimize the disposal of fine tailings into tailings ponds since the treatment of AMO is a costly and long-te1m environmental liability."

Jan 1, 1997

By Whitman E. Brown, Louis J. Erck

The installation in 1948 of a Hum-phrey~ spiral concentrator section at the Hill-Trumbull plant of The Cleve-land-Cliffs Iron Co. is the latest commercial method on the Mesabi Range being used for the recovery of fine iron ore. In two stages of concentration 84 spirals treat approximately 120 long tons per hour of minus ? in. ore. These spirals augment the production of the heavy-density plant which recovers the plus 36 in. iron from the plant crude ore. Structure of the ore is such that, when crushed, about 50 pct of the plant crude is minus ? in. size. After de-sliming in a 66 in. Akins classifier, grinding the classifier product in a ball mill and again desliming in a 78 in. Akins classifier about 15 pct of the crude ore remains to be treated in the spiral plant. Overall recovery of the ball mill feed in the Hill-Trumbull spiral plant during the 1948 season was about 53 pct of the weight and 66 pct of the total iron content. Of the actual feed delivered to the spirals from the 78 in. classifier 64.9 pct of the weight was recovered containing 73.7 pct of the total iron. The average analysis of the spiral concentrate is 55.05 pct Fe and 14.83 pct SiO2. An average of mill assays during the 1948 season is given in Table 1. The Hill-Trumbull plants treat both wash ore and jig-type ore. During the 1948 season spirals were used only on the fine sizes of jig-type ore. At times the deslimed minus ? in. size is of sufficient grade to warrant bypassing the spirals but in the main the fine size is delivered to the 48 first stage spirals and thence to the 36 cleaner or second stage spirals. In the past several years numerous Mesabi Range ores in the fine size cate- gory have been tested by a wide variety of beneficiating equipment. The prodigious amount of research devoted to the recovery of values in the fine ore reflects the dire need of the iron industry to squeeze the last possible unit of iron from the mined ore and to develop suitable equipment and processes to satisfactorily concentrate the leaner horizons as they are encountered in the process of mining. Large governmental and private appropriations have been allotted, new laboratories built, research and technical staffs increased, and operator-manufacturer cooperative agreements applied to hasten the solution of the problem. The University of Minnesota, at its Eighth Annual Mining Symposium in January 1947, dedicated as its objective the bringing to light of technological developments in iron ore beneficiation. Papers were given at that time relating to processes being developed. Specifically, these papers reviewed flotation, Baum jig, selective media concentrator, Hardinge concentrator, Dorrco sizer, heavy media concentration, Hydrotator, and the Humphreys spiral. The Cleveland-Cliffs Iron Co., after encouraging results from tests in a small pilot plant using one full size spiral, made the first commercial installation of Humphreys spirals on the Mesabi Range at their Hill-Trumbull mine, Taconite, Minn. This company

Jan 1, 1950

A low grade, refractory ore gold mine with high striping ratio such as at Macraes is always challenged in ways to improve margins. Common practice approaches used at OceanaGold Ltd Macraes are to maximise grade delivery, optimise recovery and reduce unit costs, as well as take any opportunities to incorporate new technologies and implement enhanced commercial strategies. &nbsp; The Business Improvement (BI) programme was implemented across the Macraes operations in late 2003 and is being rolled-out to all other parts of the business. The core focus of BI at OGL is to: +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; increase revenue, +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; reduce cost, and +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; improve processes. &nbsp; A dedicated BI team comprising of a manager, team leaders and business analysts were engaged to identify and manage a series of opportunities to reduce operating expenses, optimise capital outlays and generate extra revenue. The Business Improvement Programme, though in its formative phase, has begun a cultural change within the organisation. Many people are starting to challenge the way they do things and are looking for ways to continually improve business performance. &nbsp; The BI team encompasses individuals from different departments who can offer the diverse skill set necessary to produce intended results. The current team is made up of a BI manager, BI Team Leaders in Mining and Processing and analysts from Mining, Processing, Commercial and Plant Maintenance workgroups. A team member has recently been formally trained as a Six Sigma Black Belt. ] The BIÆs team role is to assist in the establishment of project management processes for each improvement idea. In addition the team will assist in tracking implementation, identifying and unblocking restrictions and limitations as well as setting up metrics to quantify the level of benefit returned and sustained. &nbsp; From a more strategic point of view, the BI team is advancing the Business Improvement capability of the company by developing long term Communication and Training strategies. These strategies will set the direction of BI initiatives in the years to come to: +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; educate the OGL workforce in basic BI techniques, +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assist the OGL workforce in applying basic BI techniques, +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; communication the direction of BI in OGL, and +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; close the information feedback loop to facilitate transparent communication between the OGL workforce and the BI team.

Jan 1, 2004

By E. Gaujot

IN connection with the question of coal waste and economy in mining, we would call the attention of those interested to an apparatus invented by M. Dernencourt, Superintendent of the Anzin Division of the Anzin Coal Company, North of France. This apparatus is known in France and Belgium under the name of prop screw-jack (vis botte), and has been used with good results in the above-named countries for some years past. M. Ponson gives, in his " Trait6 de I&apos;exploitation des Mines," a description of it (page 533), but as the description given is old, the work not widely known in this country, and as some valuable improvements have been made since, I thought it might be useful to give a description of it, having seen it in &apos;operation in 1867, while in Europe to attend the great Exposition, and on a scientific tour to the mining districts of France, Germany, Belgium, and Italy. The prop screw-jack is composed of the following pieces : I. The body or column B, Fig. 4 [Plate (I)], of oak or yellow pine, sawed square, the bark taken off, and any length, proportionate to the vein. The smallest are 10 inches diameter at the base, and 9 inches at the top, the height being from 12 to 15 inches less than the size of the vein. In the axis of this column, and at the top end, is a cylindrical opening or hole, C, 22 inches diameter, 10 inches deep, for the screw, S. II. Two wrought-iron rings, R R, to strengthen the two extremities of the column ; the rings must be put on hot. III. A cast,-iron washer, E, with hole in centre a little larger than the screw, to be put on the top of the column, and on which the nut is to rest; the top side of this washer must be faced on the lathe, also the bottom of the nut, to prevent friction. IV. The screw, S, having a total length of 12 inches and a diameter of 24 inches (for very high veins this diameter may be increased to 3 inches), and has on its top a wrought-iron plate, T,

By F. J. Smit

The Tintic Division of Kennecott Copper Corporation operates the Burgin Mine in the East Tintic District near Eureka, Utah, approximately 75 miles south of Salt Lake City. The Division was organized in 1963 to develop concealed replacement orebodies in the area located by Bear Creek Mining Company, Kennecott&apos;s domestic exploration subsidiary. Several accounts of the discovery of these orebodies and the general geology of the area have been given (1, 2). The ore is very complex and of varying degrees of oxidation and alteration. The principal metal values are lead, zinc, silver, and cadmium. The Burgin No. 2 shaft was sunk in 1963 to provide access for mining the orebodies. Much of the ore mined after this shaft was sunk was high grade and shipped directly to smelters, but concurrently it was recognized that concentration would be required to upgrade the lower grade ore in the deposits. Accordingly, in January 1967, authorization was received to construct a 500 tpd concentrator. From the beginning it was expected that the characteristics of the mill feed would vary widely and unpredictably as mining progressed. This paper summarizes the characteristics of the ore, the test work upon which the plant design was based, the engineering and construction, and the present operation of the facility eighteen months after startup. ORE CHARACTERISTICS The Burgin ore is a complex assemblage of minerals from replacement of limestone. The replacement and alteration occurred in at

Jan 1, 1970

By Y. J. Wang

A critical path approach is presented for the problem of mine ventilation net- works where regulators and fans are employed to control the airflow distribution which is preassigned. The problem is a classic one which arises in mine ventilation planning. By identifying the analogy between the network for controlled flow and that for CPPI, the applications of the well known CPM technique to the ventilation network problem become straight- forward. The mathematical formulation of the problem is presented and the solutions are illustrated with examples. The effect of booster fans on the total air power consumed in a ventilation network are also discussed.

Jan 1, 1981

May I first of all say that I am fully conscious of the great compliment paid to me when I was invited to accept the Presidential Chair for this current year. I realise that it is an onerous task by reason of the fact that the Chair has been occupied in the past by so many able and distinguished men, and I realise also that I have been set a standard which is hard to emulate. &quot;It is my desire however, in accepting the post that I may be able to contribute in some small measure to the further advancement Of the aims and objectives of the Institute and I thank you all for the confidence you have shown in me.Secondly, on behalf of the Company and in my Presidential capacity, I want to extend to each and everyone of you a hearty welcome to Whyalla and I hope that you will all return to your respective fields of endeavour feeling that you have had a most interesting, enjoyabIe and instructive time with us here in Whyalla.In this year of 1951 marking as it does the culmination of the first 50 years of Federation in Australia and yet another half century of human endeavour and progress, we are brought to a point where it is perhaps natural that we should pause, to review what has been achieved, in that span of time, and to look at the tasks ahead.It is no exaggeration to say that the story of Australian development since the inauguration of the Commonwealth 50 years ago has no more remarkable chapter than that of the-growth of its manufacturing industries.Each decade has borne witness to steady and substantial growth of our secondary industries and whilst it is true that our financial well-being still rests heavily on our primary production, we have, as a nation, moved surely in the direction of a more balanced economy. More and...

Jan 1, 1951

By B. D. Crawford, S. A. Falconer

ONE of the outstanding achievements in connection with this country&apos;s war efforts has been the ability of our mining industry to supply from domestic sources many of the minerals of strategic importance that formerly were obtained principally from abroad. In order to meet the war-born demands for these scarce minerals, it has frequently been necessary to develop special methods for treating ores and waste products hitherto considered too low-grade to be workable; and to improve the efficiency of older beneficiation processes. Important in this respect have been the recent technological advances in the field of froth flotation of nonsulphide minerals. Because of the refractory nature of many of these domestic ores, and, in many cases, the limited available technical data regarding their treatment, much research work has been necessary. The following examples describe the procedures and reagents used, and the results obtained, in certain laboratory flotation investigations conducted by American Cyanamid Company&apos;s engineers at the Cyanamid Ore Dressing Laboratory on ores containing such minerals as scheelite, manganese oxides and carbonate, ilmenite, brookite, kyanite, garnet, spodumene, mica, feldspar, celestite, fluorite, chromite, corundum, and cassiterite. In presenting these data, we wish to point out that many of the minerals listed have previously been tested, and their amenability to flotation reported, by other investigators-notably those of the United States Bureau of Mines. In some instances the procedures and reagents used in the treatment of some of the following described ores follow rather well-established lines, and with one or two exceptions, the reagents used were well known. However, many of the ores tested did not respond well to simple conventional procedures and it was necessary to adopt special methods of conditioning and desliming, reversal of the usual order of floatability of some of the minerals, multiple cleaning, etc., in order to secure separations. Except where otherwise noted, all numbered and trade-marked reagents mentioned in this paper are marketed by the American Cyanamid Co. or the American Cyanamid and Chemical Corporation. TUNGSTEN ORES Tungsten minerals, vitally important in the war industries of the United States, rank high in the list of those we formerly had to import in order to supply our needs. Most of our domestic ores of tungsten contain scheelite as the valuable mineral. Today there are in the neighborhood of twelve tungsten operations in this country where flotation is used as the main or accessory form of benefication. It has, of course, been known for some time that scheelite and other tungsten minerals respond to treatment by flotation.

Jan 1, 1944

By R. Bruce Ferguson

"The Kettle River Operation of Echo Bay Minerals Company is located about thirty kilometers north of the town of Republic in northeastern Washington State. In tum, Republic is about a hundred and seventy kilometers north and a little west of the city of Spokane, Washington. It is also about fifty kilometers south of the town of Grand Forks, BC, Canada. At this time it is the only gold mining and milling operation in the State.Tailings are stored in a double lined, zero discharge facility. It became evident in mid 1996 that the rate of free water accumulation in the tailings pond was going to result in the level in the pond reaching its permitted freeboard elevation long before the solids plus pore water capacity was reached.We then embarked on a mission to manage tailings pond water on several fronts: reduce fresh water usage in the process, divert spring seeps and surface runoff and install a system to enhance evaporation.IntroductionThe Republic area is an historic gold mining district. Hecla operated its Republic unit from 1892 until closure in 1994. The Kettle River Operation processing plant is located in the San Poi! river valley at an elevation of just under a thousand meters. The facility consists of a ninety thousand ton ore storage pad as the mines are remote and truck haulage is subject to interruption due to weather and road restrictions, jaw and cone crushing with screening, rod and ball milling to an eighty percent passing size of seventy five microns. This is followed by preaeration with high purity oxygen supplied by a vacuum pressure swing adsorption plant plus lead nitrate addition to achieve passivation of the sulfide mineralization such as chalcopyrite, pyrite and pyrrhotite. Conventional cyanide leaching and carbon in pulp adsorption completes the loop. Tailings are treated with air/S02 to achieve cyanide destruction. Plant capacity is 1,815 tons per day. Our license requires that there be no detectable free cyanide in the tailings pond water and a maximum of forty parts per million weak acid dissociable cyanide. The operation started in 1989 with production from the Overlook Mine located about five kilometers further up the same valley at an elevation of twelve hundred meters, hence the location of the mill. Current mine production comes from Lamefoot in the Curlew Lake valley, about ten kilometers distant, and K2 in the Kettle River valley about fifty kilometers away. Both are at an elevation of about 800 meters. Lamefoot produces 1,360 tons per day and K2, 455. Both are underground operations."

Jan 1, 1998

By R. S. C. Rogers

Semiautogenous milling was the subject of 18 papers presented at the SME Fall Meeting in Albuquerque, NM. The process design and scale-up of SAG mills was discussed in several papers. These included a review of testing methods for the sizing of SAG mills by Barrett and Allan. Austin et al. presented an improved simulation model for SAG mill grinding, with model validity demonstrated against pilot plant SAG mill test results. Rogovin et al. presented some pilot plant results relating to the charge motion, hold-up, and particle size segregation in SAG mills. A number of papers described improvements achieved in operating SAG mill circuits. These included presentations by Dailey concerning mills at the National Steel Pellet Co., by Brown and Pipke concerning the Island Copper grinding circuit, by Lovering of Afton Mines Ltd., and by Bartrum et al. of Kidston Gold Mines Ltd. Bush and Hegerle of Amax also discussed SAG mill operations at the company&apos;s Henderson mill. They addressed the topics of SAG mill grinding economics. Other papers addressed the topics of SAG mill control (Vanderbeek et al. and Pennington), grinding media (Meulendyke et al.), liners (Kjos), and fabrication (Carr and Utley). The 1985 AIME Annual Meeting in New York featured four technical sessions concerning size reduction technology and practice. Papers involving fundamentals included one by Hinde describing simulation model usage for quantifying the classification and concentration of heavy minerals in grinding circuits. Another, by Rogers et al., discussed simulation models that were used as a design aid in evaluating screens versus hydrocyclones for fine grinding circuits. Arbiter discussed dimensional considerations in grinding mill design, and Schwechten and Schonert proposed the use of a high pressure roll mill as a means for reducing energy requirements in fine grinding. Internal classification in tumbling mills was the subject of a paper by Hogg and Rogovin. The mechanism of internal classification were identified and their effects illustrated. Simulation for the process design of ball mills was exemplified in a paper by Rogers, Austin, and Brame concerning phosphate grinding in laboratory to large diameter mills. The incorporation of liberation into size reduction models was the subject of papers by Austin et al., Herbst et al., and Choi et al. Gupta used simulations models to further investigate zero order fines production in ball and rod mills. Of the published literature, many articles on size reduction were published in various publications in 1985. Articles concerning ball mill grinding included an analysis of interstitial gas effects in dry grinding by Cottaar et al., an analysis of mill grinding noise by Watson, studies of factors affecting breakage rates in dry milling by Gupta et al., and in wet milling by Tangsathitkuchai and Austin. Austin and Klimpel presented two papers concerning ball wear and ball size distribution effects. Koka et al., and Gotsis et al., described recent developments concerning the Szego mill. A model for hammer milling circuits was described in papers by Gotsis et al. and Gotsis and Austin. Heim et al. reported on wet grinding in Perl mills, and Kuga et al. presented findings concerning pulverizing in a screen mill. Studies of grinding effects on particle surfaces were published by Meloy and Hofmann et al., and Scieszka proposed a technique to investigate pulverizing properties of coals. Austin and Rogers discussed factors of powder technology of significance in industrial size reduction in mills and crushers. (Space limitations preclude listing of references. A complete list is available from author.)

Jan 5, 1986

By M. Thérien, M. Rémillard

"Data from two industrial plants are treated by mass balance package BILMAT. The first application concerned a base metals/precious metals (PM) producer and the second, implementation of a hydrocyclone for the recovery of iron chips in the granite industry. Also LOTUS 123 software can easily be adapted for laboratory test mass balances using an IBM-PC computer. INTRODUCTIONThe present paper deals with two different BILMAT program applications. The first application concerns a copper-zinc-gol d-sil Yer producer based in North-western Quebec and the second, concerns the iriplementation of a hydrocyclone for the recovery of iron chips in Quebec granite company.Afterwards, we deal with some LOTUS 123 software applications for laboratory test mass balances using an IBM-PC.1. Base metal and P.M. producerNoranda Inc, Mattagami division, which operates mines in North Western Quebec, produces copper and zinc concentrates from a sulphide ore. Small amounts of gold (0,34 g/t) and silver (20 g/tl are present. At the time of the study, only 30% of the silver content was recovered in the copper concentrate. The main objective of this study is, to evaluate the metallurgical behaviour of silver in the flotation circuits, to increase its recovery in the copper concentrate and therefore to improve its final economic value. It is then worthwhile to identify the silver bearing minerals and to determine the critical flotation stages where they are lost. The methodology proposed is based on the coupling of a mineralogical study and a detailed mass balance ca1cu1ation in the flotation circuit performed using the BILMAT mass balance package (1, 2, 3).The results are discussed with respect to the distribution of silver in the circuit. The recoveries obtained at the various separation stages for the minerals present in the ore are also discussed."

Jan 1, 1987

By Edwin Ludlow

For many years, coal has been known to exist in the valley of the Sabinas river, in the State of Coahuila, and for about 15 years it has been worked by the Mexican International Railway Co., which opened mines for its own fuel-supply when the railway was built, and has been mining continuously ever since. The coal-basin worked by this company lies along the Sabinas river, principally on the SW. side. It covers a wide area and has been carefully prospected, but only in a few parts have the beds been found sufficiently thick and regular for economical operation. This Sabinas basin was considered the only one in this field, until, in the Spring of 1899, the Las Esperanzas basin was found by Messrs. J. L. Elliot and E. D. Peters, who were in Mexico looking after some copper-properties. After a further examination by Mr. James T. Gardiner, of New York, the Mexican Coal & Coke Co. was organized in June, and active work was begun on Nov. 5, 1899. The coal-field of Las Esperanzas, situated in the State of Coahuila, about 85 miles SW. of Eagle Pass, Texas, adjoins and runs parallel with the Sabinas basin—an anticlinal separating the two outcrops by about 2 miles. Fig. 1 is a sketch-map of a part of the basin. The coal-formation is in the Upper Cretaceous, and corresponds with the Laramie measures of the United States. The following geological section, taken in Nogales canon, shows the measures between the massive limestones forming the Sierra de la Santa Rosa and the outcrop of the coal: Section. Feet. Limestone,...Unknown. Blue shale,.........110 Shale and sandstone,.. 60 Bed of fossiliferous shale,. 60

Jan 1, 1902

THE Copperton mill in reality was a sort of proving ground. It was. designed to serve three purposes: (1) to verify the accuracy of the mine sampling by actually treating substantial tonnages of ore, (2) to demonstrate on a reasonably large scale the percentage of the copper in the ore that could be recovered, and (3) to permit the testing of various kinds of machines and devices for crushing and concentrating the ore, so as to guide the engineers in designing the proposed 6000-ton milling plant at Garfield. As a matter of fact, it contained a lot of second-hand equipment sent by MacNeill and Penrose from the works of the United States Reduction &Refining Co. in Colorado; and it was by no means a model installation. Probably it would have been even less efficient, except for the skillful work of George O. Bradley and-Frank-G, Janney, both of whom had worked with Jackling at Mercur. Bradley was a mechanical engineer employed to design the plant. Later he directed the design of the concentrator at Garfield and remained as consulting mechanical engineer to the company until 1915. Janney, who afterwards became manager of mills, a position that he retained until his death in 1916, was a skilled mechanic at the Golden Gate mill at Mercur when Jackling built the plant in 1897. His flair was making machinery do what it was intended to do. He was not an ore-dressing engineer in a technical sense; but Jackling him- self was a specialist in this respect as well as in designing and construction and Janney&apos;s mechanical aptitude made him a particularly valuable man in the Utah organization. John McDonald, another of Jackling&apos;s Mercur associates, was the first mine superintendent. With practically all of the available funds earmarked for construction of the Copperton

Jan 1, 1933

By Stanley J. LeFond, Neal Davis

Drilling an oil well or most other types of drilling or coring is no longer a simple and uncomplicated operation. Drilling today at depths which exceed 30,000 ft is hazardous and requires personnel with long and varied experience in drilling. It also requires extensive experience and knowledge in the use of materials which are added to the drilling fluid or "mud," more often than not materials utilizing an industrial mineral. The drilling fluid can vary from a simple mixture of water and "mud" to a very sophisticated, scientifically compounded drilling fluid. Industrial Minerals Used in Drilling Fluids Industrial minerals which are commonly used in oilwell drilling and completion are listed on [Table 1]. The most important minerals, determined by sales, are bentonite and barite. The other minerals listed are either used to achieve a specific purpose or are used regularly but in limited quantities. The main suppliers of drilling fluids internationally are Magcobar Div., Dresser Industries, Inc.; Baroid Div., National Lead Co.; IMC Drilling Mud Co., (a subsidiary of International Minerals and Chemicals Corp. and Halliburton Co.) ; and Milchem, a division of Baker Industries. Most of the industrial minerals are found in North America, with barite mines and processing plants located in Nevada, Arkansas, Missouri, and Arizona, and bentonite mines near Graybull, Wyo. Other mines, such as those in Nova Scotia, are capable of shipping to South America and to the European and Middle East countries. Most of the materials processed by any of the suppliers must conform to specifications set by the American Petroleum Institute (API) or the Oil Companies Material Organization (OCMA). These specifications provide for uniform physical and chemical properties of the materials to be sold on the open market.

Jan 1, 1975

A MINING institute open to all men interested in any branch of the mining industry will be held at the Col-lege of Mines, University of Washington, Seattle, during the week beginning March 5. Prospectors, miners, mine owners, persons interested in metallurgy, investors in min-ing enterprises, and the public generally are invited to at-tend. This institute will take the place of the Winter Min-ing Session which originated at Seattle in 1897 and con-tinued for twenty-eight years. The complete new equip-ment of the Mines Laboratory will be used to give demon-strations of new machines and processes of mining, ore dressing, and metallurgy. This year the ceramic industry, including cement and branches of clay working of special Importance in the Northwest, will be included in the insti-tute. All instruction will be given by specialists. Prominent technical men and managers will give lectures on their special subjects. Among the speakers engaged are G. T. Jackson, formerly superintendent of the Alaska-Gas-tineau and the Chichagof mines, who will speak on the mining of large bodies of low-grade ore; R. F. McElvenny, superintendent of the Tacoma Smelter, on the nature of contracts that a smelter can offer to mines and prospects; M. D. Leehey, mining lawyer, on some popular errors re-garding the mining law; H. H. Townsend, on the explora-tion and purchase of prospects by operating companies; J. L. McAllen, on quartz mining in the Willow Creek dis-trict, Alaska; F. Powell, on gold dredging. In the evenings, lectures illustrated by stereopticon views and moving pic-tures will be given. The week will close with an excursion o mines and plants.

Jan 3, 1928

By C. A. Mitke

(Butte Meeting, August, 1913.) 1. Character of Gases which Caused Helmets to Get Out of Order. DURING September, 1911, the fire area, in the Lowell mine continually increased. and gases resulting from the fire came through the upcast shaft. These gases contained such a large percentage of sulphur dioxide that the men were unable to go up and down on cages, and, within a comparatively short time, repairs in the shaft were found to be necessary. Since the fire was in sulphide ores and extended into certain timbered sections, the gases contained varying amounts of SO2, CO2, and perhaps, at times, CO. The temperature in the shaft was generally about 97°, and the relative humidity from 97 to 99.5 per cent. The corrosive action of the fumes became apparent when the cables had to be changed more often than usual, the heads of lag screws in the guides of the shaft disappeared, and the cages needed frequent repairs. It also became necessary to repair two compartments of the shaft by putting in 150 ft. of new guides between the 600 and 800 levels and lag screws in nearly all the old guides from the surface to the 800 level. 2 Ordinary Methods of Testing Helmets which were Unsatisfactory. These conditions required all work to be done by men wearing oxygen helmets. The Draeger type was tried, and was used until all repairs were completed. At first the helmets were tested for air circulation and air tightness .and the injector was tested by water gauge according to the methods recommended by the Draeger Oxygen Apparatus Co. Six arrangements, covering these different tests, are illustrated in the catalogue and circulars of the company.

Jan 7, 1913

By J. J. Gilman

WHEN a cleavage crack that is moving through a crystal intersects a screw dislocation, a jog is created in the crack front. As the crack continues to move, the jog leaves behind a cleavage step. This mechanism was proposed by Amelinckx and Votava,&apos; Pratt, bnd Gilmanh t about the same time. At that time the evidence for the mechanism was largely indirect. Other evidence has been presented by Low, Bilby and Smith,5 and Forty.&apos; It is the purpose of this paper to present more direct evidence of this mechanism and to show that observations of cleavage steps can be used to detect screw dislocations. Experimental Lithium-fluoride crystals that were purchased from the Harshaw Chemical Company, as well as natural mineral crystals and metal crystals, were used in the experiments. Although cleavage steps can be observed on transparent crystals with a metallurgical microscope, the contrast is poor. Marked improvement in the contrast is obtained by depositing thin (1000A) films of silver or aluminum onto the surfaces. The contrast also can be improved by using a phase-contrast microscope, but the simpler silvering method gives just as good results. Tolansky interferometric microscopy, and electron microscopy were used to measure the heights of cleavage steps. The etching techniques developed by Gilman and Johnstonh ere used to detect dislocations in the LiF crystals. Results The dislocations that create cleavage steps can originate in three ways: a) They can be grown into crystals b) They can be introduced by plastic deformation prior to cleavage c) They can be formed just in front of the tip of a propagating cleavage crack.&apos; These three situations will be considered in turn. Grown-in Dislocations—It is not possible to see the individual monomolecular cleavage steps that emanate from isolated screw dislocations in crystals.

Jan 1, 1959

Discussion of the paper of LAWRENCE ADDICKS, presented at the Salt Lake meet-ing, August, 1914, and printed in Bulletin No. 91, July, 1914, pp. 1671 to 1674. JAMES H. PAYNE, Baltimore, Md. (communication to the Secretary*). -Mr. Addicks&apos;s account of the behavior of the nodulizer at Chrome on blast-furnace flue dust leads me to outline what has been done so far upon the application .of the same apparatus to fine sulphide concentrates. As Mr. Addicks states in his paper, the conditions prevailing in the test kiln at Yorktown in the demonstration I made for him upon Chrome material were strongly oxidizing; so much so that the sulphur was roasted down to less than 1 per cent. It is therefore to be expected that the first test made upon sulphide ore a short time after this, in which Ducktown green ore fines were used, did not show very promising results. Although the Ducktown ore contained only 13.52 per cent. of sulphur its gangue was quite fusible, and the intense heat generated by the oxidation of. the extremely fine sulphide particles slagged the mass, bringing about a condition approximating that of a Brückner roaster in distress. During the spring and summer of 1912, the writer kept working upon different schemes to cut clown this slagging. Two successful methods were finally worked &apos;out embodying opposite principles, one promoting oxidation of the finer particles and the other retarding. their oxidation. In the early part of the present year the writer succeeded in interesting the Braden Copper Co. in nodulizing, with the result that an extensive series of tests were made at Yorktown upon oil-floated concentrates covering quite a wide range in analysis. These tests led to trials in the Chrome rotary on the part of the U. S. Metals Refining Co. of Minerals Separation concentrates which they had in stock, and later to test runs to check up the Yorktown runs on Braden concentrates. The large-scale tests checked up with the Yorktown tests in every way (except fuel consumption, which was, however, correctly predicted), and led to the Braden company&apos;s decision to adopt the process at Braden. The fuel consumption upon oil-floated concentrates is not over 6 gal. per ton and in many cases is less. The action in the furnace is independent of the sulphur content, and there is actually less tendency to form nose rings in the Chrome rotary than upon flue dust. It is believed that the improvements entering into the design of the Braden kilns will cut down the nose-ring trouble to where it will no longer be a drawback to the process.

Jan 11, 1914

By Charles Enzian

This report is issued by the Bureau of Mines as one of a series dealing with methods of increasing safety and efficiency in mining operations. It is intended purely as a preliminary statement of the present development of hydraulic mine filling as conducted in the anthracite region of Pennsylvania. A discussion of different methods, their variations and modifications, as well as their probable extension as a result of amplified tests of the various roof-supporting materials, will be presented in a future bulletin. The history of the development of the anthracite-mining industry, from the time when the Indian tribes in the Wyoming and Lacka- wanna Valleys first discovered the existence of "stone coal," on through subsequent events-the purchase of lands containing enor- mous deposits of coal for insignificant sums of money, the develop- ment of the first mine, the formation of the first company, the build- ing of canals and railroads-up to the present time when the industry has become of such tremendous importance to the prosperity of north- eastern Pennsylvania and of the Nation itself, is intersprinkled with romance, tragedy, and pathos. The great economic lessons to be learned from a study of mining operations in the anthracite region suggest to the person interested in the efficient utilization of natural resources the need of applying such methods as will make possible the conservation to posterity of this invaluable deposit of coal that has resulted from the operation of the processes of nature during probably hundreds of millions of years. It is the opinion of many prominent mining men familiar with mining operations in the United States and abroad that under certain conditions the most practical way of preventing loss of unmined coal in pillars and of protecting surface property from damage by sub- sidence is by filling the workings with refuse material. This bulletin aims to present a general discussion of hydraulic mine filling, its origin, development, and practicability in anthracite mining.

Jan 1, 1913