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By R. Karl Zipf

Multiple seam mining interactions caused by full extraction mining, whether due to undermining or overmining, frequently involve tensile failure of the affected mine roof. The adverse ground control conditions may prevent mining for both safety and economic reasons. Prior researchers have identified the geometric, geologic and mining factors controlling multiple seam mining interactions. This numerical study examines the mechanics of these interactions using a modeling procedure that 1) incorporates the essential constitutive behavior of the rock such as strain- softening of the intact rock and shear and tensile failure along bedding planes and 2) captures the geologic variability of the rock especially the layering of weak and strong rocks and weak bedding planes. Specifically, the numerical study considered the effect of vertical stress, interburden thickness, and the immediate roof quality of the affected seam in both undermining and overmining situations. The models show that for overburden-to-interburden thickness (OBAB) ratios of less than 5, interactions do not occur, and that for OBAB more than 50, extreme interaction is a certainty. In between, the possibility of an interaction was found to depend on gob width-to-interburden thickness ratio, site specific geology and horizontal stress to rock strength ratio in addition to the OBIIB ratio. The models also showed that horizontal stress was profoundly altered well above or below a full extraction area and that these changes are likely to influence the success or failure of multiple seam mining. The role of horizontal stress in multiple seam mining interactions has received little attention in prior investigations. Four factors control the mechanics of multiple seam mining interactions: 1. vertical stress concentration 2. horizontal stress concentration 3. stress re-direction 4. bedding plane slip bands A combination of vertical and horizontal stress increase and high stress gradients in the vicinity of full extraction areas re-orients principal stresses into a very unfavorable direction. This seemingly small stress re-orientation has a profound adverse effect on bedded rock.

Jan 1, 2005

By Roy Lindgren

Since the year 1643, when the first blast furnace in America for treating iron ore was built at Saugus, Mass., out of mica schist quarried in the neighboring district, the procurement of a suitable refractory for furnace lining has been a problem of concern to the operators of furnaces. The stacks built of mica schist continued to smelt iron ore until about 1836, when, according to F. H. Norton, the first firebrick were produced1, at Queens Run, Pa. Other writers speak of brick having been molded and burned in Massachusetts about the year 1834. In 1841, Andrew Russell began to produce medium refractory plastic clay brick near East Liverpool, Ohio, that were used for lining blast furnaces1. The well-known Kentucky clay-producing district was not opened up until the year 1871, but since then it has produced a large percentage of the linings for iron blast furnaces. While some strides have been made by the refractories industry during the 100 years that have passed since the first firebrick were produced, it has been only during the last two decades that any real progress has been made towards bettering the product, even though the method of production had improved. Perhaps the fault lies with the user of the brick rather than with the producer, for not sooner demanding a supe¬rior product. During the past 15 years the tonnage produced per lining has increased from 500,000 gross tons to 1,000,000 gross tons, and now some furnaces are producing 1,600,000 gross tons and better on a single lining. It is true that enlarged capacity of furnaces and improved practice have accounted for some of this increase in tonnage, nevertheless better quality in firebrick must be given credit for its share. However, we are not yet ready to say that we have reached a maximum life of furnace lining. We believe that a better product can be produced and that the refractories industries of America will, through their extensive research depart-

Jan 1, 1936

By Dean S.

Further discussion at the The Midland Counties Institution of Engineers' general meeting held in Nottingham on 6th May 1916, of the paper published in Trans. I.Min.E., vol.L, 1915, p.179, included brief oral contributions by Bragge G.S., Lewis W.H. and Hepplewhite W.H.

Dec 1, 1916

By Roy Lindgren

SINCE the year 1643, when the first blast furnace in America for treating iron ore was built at Saugus, Mass., out of mica schist quarried in the neighboring district, the procurement of a suitable refractory for furnace lining has been a problem of concern to the operators of furnaces. The stacks built of mica schist continued to smelt iron ore until about 1836, when, according to F. H. Norton, the first firebrick were produced1, at Queens Run, Pa. Other writers speak of brick having been molded and burned in Massachusetts about the year 1834. In 1841, Andrew Russell began to produce medium refractory plastic clay brick near East Liverpool, Ohio, that were used for lining blast furnaces1. The well-known Kentucky clay-producing district was not opened up until the year 1871, but since then it has produced a large percentage of the linings for iron blast furnaces. While some strides have been made by the refractories industry during the 100 years that have passed since the first firebrick were produced, it has been only during the last two decades that any real progress has been made towards bettering the product, even though the method of production had improved. Perhaps the fault lies with the user of the brick rather than with the producer, for not sooner demanding a supe-rior product. During the past 15 years the tonnage produced per lining has increased from 500,000 gross tons to 1,000,000 gross tons, and now some furnaces are producing 1,600,000 gross tons and better on a single lining. It is true that enlarged capacity of furnaces and improved practice have accounted for some of this increase in tonnage, nevertheless better quality in firebrick must be given credit for its share. However, we are not yet ready to say that we have reached a maximum life of furnace lining. We believe that a better product can be produced and that the refractories industries of America will, through their extensive research depart-

Jan 1, 1936

By Roy Lindgren

SINCE the year 1643, when the first blast furnace in America for treating iron ore was built at Saugus, Mass., out of mica schist quarried in the neighboring district, the procurement of a suitable refractory for furnace lining has been a problem of concern to the operators of furnaces. The stacks built of mica schist continued to smelt iron ore until about 1836, when, according to F. H. Norton, the first firebrick were produced1, at Queens Run, Pa. Other writers speak of brick having been molded and burned in Massachusetts about the year 1834. In 1841, Andrew Russell began to produce medium refractory plastic clay brick near East Liverpool, Ohio, that were used for lining blast furnaces1. The well-known Kentucky clay-producing district was not opened up until the year 1871, but since then it has produced a large percentage of the linings for iron blast furnaces. While some strides have been made by the refractories industry during the 100 years that have passed since the first firebrick were produced, it has been only during the last two decades that any real progress has been made towards bettering the product, even though the method of production had improved. Perhaps the fault lies with the user of the brick rather than with the producer, for not sooner demanding a supe-rior product. During the past 15 years the tonnage produced per lining has increased from 500,000 gross tons to 1,000,000 gross tons, and now some furnaces are producing 1,600,000 gross tons and better on a single lining. It is true that enlarged capacity of furnaces and improved practice have accounted for some of this increase in tonnage, nevertheless better quality in firebrick must be given credit for its share. However, we are not yet ready to say that we have reached a maximum life of furnace lining. We believe that a better product can be produced and that the refractories industries of America will, through their extensive research depart-

Jan 1, 1937

By Ancel St. John

Defects in the interior of metal objects are troublesome to both manufacturer and user. For the former, they frequently increase manufacturing cost through the rejection of material when defects appear after considerable work has been done. For the latter, they often cause damage to equipment, personal injury, or loss of life when a part, which has passed all inspections and has been put in service, gives way because of a hidden flaw. Methods of testing that locate such flaws without subjecting the specimen to possible, if not actual, destl-uction are few; x-ray examination, whether fluoroscopic or radiographic, is one. Hitherto, however, x-ray examination has been restricted to objects of nearly uniform thickness and regular outline; the inspection of such articles as those shown in Fig. 1 has been inconvenient and unsatisfactory. This figure represents a group of 5/16-in. hexagonal-head machine bolts,

Jan 1, 1923

By Ancel St. John

Defects in the interior of metal objects are troublesome to both manufacturer and user. For the former, they frequently increase manufacturing cost through the rejection of material when defects appear after considerable work has been done. For the latter, they often cause damage to equipment, personal injury, or loss of life when a part, which has passed all inspections and has been put in service, gives way because of a hidden flaw. Methods of testing that locate such flaws without subjecting the specimen to possible, if not actual, destl-uction are few; x-ray examination, whether fluoroscopic or radiographic, is one. Hitherto, however, x-ray examination has been restricted to objects of nearly uniform thickness and regular outline; the inspection of such articles as those shown in Fig. 1 has been inconvenient and unsatisfactory. This figure represents a group of 5/16-in. hexagonal-head machine bolts,

Jan 1, 1923

Meeting called to order by President Herres, eleven o'clock A. M., Monday, August 27, 1928. Address of Welcome by Mr. T. S. Taliaferro, Jr. Address by Mr. William Redshaw, Chairman of the Rock Springs Chapter of the Institute. Paper, "The Effect of Mechanical Coal Mining on Mine Safety," by Lyman Fearn, State Mine Inspector, Wyoming. Paper, "Safety," F. C. Miller, Chief Chemist, Colorado Fuel & Iron Com¬pany, Trinidad, Colorado. Afternoon session, meeting called to order two P. M. On suggestion of Mr. William Littlejohn, the President appointed a special resolutions committee, consisting of Messrs. P. J. Quealy, R. L. Hair and William Littlejohn, to draft resolutions protesting against the granting of a franchise for piping natural gas into Salt Lake City, to be sent to the City Commissioners of Salt Lake City, with carbon copy to the Utilities Commission of Utah. The Committee submitted resolutions which, upon motion of Mr. Littlejohn, and seconded by Mr. Butler, were adopted and sent by telegraph to the Utilities Commission and the City Commissioners.

Jan 1, 1928

Attempt has been made to determine the nature of charge on activated carbon surface by studying the electro-kinetic properties of the carbon in the presence of cations, anions and aurocyanide solutions. The zeta-potential measurements were made in the presence of individual ions and also in combinations. The cations and anions chosen were those commonly associated with gold bearing ores in Kalgoorlie area. It was found that the iso-electric point of Norit Carbon was at pH 4.45; below this pH the charge was positive, while above, it was negative. In the absence of gold cyanide solutions and in the presence of individual cations the i.e.p. shifted to the alkaline range (pH 7.2-8.5) while in the presence of anions the i.e.p. was shifted to less than pH 3.5. In the presence of aurocyanide solutions, the iso-electric point was still in the acid region irrespective of whether anions or cations were present. The probable mechanism for such a behaviour has been attempted after measuring the specific conductivities of solutions before and after gold adsorption, by studies using the electron- probe-mirco-analyser, and S.E.M. on the carbon surface.

Jan 1, 1982

By AIME AIME

DESPITE the meetings and discussions on over- production the situation still continues to grow worse instead of better. The demand for oil has dropped to 2,700,000 bbl. per day. On the other hand domestic production has risen to 2,700,000 bbl. with prospects of further increases, and if imports and natural gas-gasoline be added to this the current supply is about 3,100,000 bbl. per day. Though during the summer and early fall the demand may exceed this figure for a few months the prospects are that 'the average demand during 1929 will be at least 200,000 bbl. per day less than the present current supply, meaning additions to stocks over the year of about 75,000,000 bbl.

Jan 1, 1929

At first glance the staid Joralemon background does not seem to equate with the life of adventure that irresistibly called me for over 70 years. But my ancestors had their adventures too. My father's family were Dutch Reformed Protestants who had energy or daring enough to come to America to escape the Catholic persecution that followed the Massacre of St. Bartholemew. The first Joralemon came from Friesland to New Amsterdam m 1636, just after Peter Stuyvesant. My father's mother's family, the Berdans, were French Huguenots who came to northern New Jersey only a little later to escape the Catholic domination in France. Some say that the first Berdan to come to America was given all the land between the Passaic and the Hacken-sack Rivers by King James. Whatever, the Berdan family settled there and was able to make a scanty living by farming and selling their produce in Manhattan. The spirit of adventure in my mother's family was just as tenuous. Gamaliel Beaman was pastor of a shipload of Puritans who came to Massachusetts in 1636. Gamaliel's descendents were peaceful farmers and some ministers in New England and later New York State. They had got all of the adventure out of their systems in the long and dangerous voyage across the Atlantic to escape religious persecution. The Joralemons and the Berdans married into families that had been in America almost as long as they had. On my father's side the Berdans, Doremus, DeGreys, Vanderbeeks, and Varicks showed by their names their Dutch or French Huguenot stock. The only one who achieved any fame was Peter Varick, who was George Washington's military secretary during the American Revolution. After this he was nine times mayor of New York and was one of the founders of Kings College, later Columbia University. He was responsible for one of my few ancestral claims to distinction. When the Marquis de Lafayette made a fare-

Jan 1, 1976

By Douglas Talley

This report describes a 4-inch diameter borehole probe which contains a low light level TV camera, magnetic compass, light illumination source, bottom/water detector sensor and a pointing angle sensor. The camera viewing angle is at a right angle to the probe's body. All data from the sensor is multiplexed into the closed circuit camera video for transmission on a single 50 ohm coaxial cable to a surface control unit. Likewise control of the probe's power, zoom lens, focus, panning and aperture is accomplished via a down-link multiplexed on the same cable.

Jan 9, 1984

By Eugene A. Lang, William R. Archibald

Early in 1972, Rocky Mountain Energy Company approached MARCONAFLO with a unique request for assistance. They controlled a series of scattered ore deposits in a remote section of Wyoming which had become increasingly valuable despite their relatively small size, great depth and low grade. At the time, MARCONAFLO was in the process of developing a tailings reclaim system which was based on the use of submersible capsules. It appeared that this basic concept might be adapted to slurry uranium ores and pump them to the surface through a bored hole. This presentation will review for you the development of this unique and potentially very important application of MARCONAFLO technology. This first slide (SLIDE 1) depicts the total mining concept envisioned by MARCONAFLO and Rocky Mountain Energy Company. A series of six self-contained mining units would be positioned through boreholes into the ore strata. An oscillating MARCONAJET would direct a high pressure jet stream into the orebody and put it into a slurry which would flow back to a slurry pump. The slurry would then be pumped to the surface and to a collection tank from which it would be transferred to processing. Both the MARCONAJET and the slurry pump would be actuated and controlled by means of a hydraulic power console mounted on the trailer behind the service tower. By means of a high pressure water pump also mounted on the trailer, return water from processing would be delivered to the MARCONAJET to slurry the ore. Tailings would be returned to a backfill unit for redepositing in the mined-out cavities. A drill rig would precede the mining, and it was estimated that this configuration would represent an optimum system for most effective equipment utilization.

Jan 1, 1976

By R. R. Potter

"IntroductionAlthough iron formations were recognized in western New Brunswick about 1820, commercial production was not achieved until 1848. The Jacksonville deposits near Wood stock were developed first, and ore was treated at a blast furnace constructed 5 km to the southeast on the Saint John River. Several charcoal burners were also constructed. Pig iron was produced sporadically until 1884, when operations were finally suspended. There was little further interest in the area until 1953, when Stratmat Ltd. initiated an ambitious exploration program. At the same time, the company carried out research on an electric-reduction process to produce metallic iron and ferromanganese. The technical feasibility of this process (Udy process) was confirmed, however the high energy costs were prohibitive and work ceased in 1957. Some metallurgical research was carried out by Mandate Refining Ltd. about 1970 and more recently by the New Brunswick Research and Productivity Council.The Years Prior to 1848New Brunswick became a separate province in 1784, shortly after the influx of a large number of Loyalists from the United States. Man y of these people sett led along the Saint John River, including the area of excellent farmland near the present town of Woodstock.There were indication s that some of these earl y settlers recognized iron formations in the vicinity of Woodstock about 1820, however the nature of the deposits was not known until 836 when Dr. C.T. Jackson, a geologist commissioned by the Stat e of Maine, investigated the mineral potential of the area. Jackson (1836) described the ""ore"" as compact red hematite yielding 44 per cent pure metallic iron, and suggested that sizable tonnages may be present. It was about this time that an extensive limonite deposit was found in north-central Maine, near Mt. Katahdin. Other iron deposits were found in the Nictaux area of Nova Scotia, and a few years later at Londonderry."

Jan 1, 1983

By Anne Lemnitzer

When a major storm system stalled over Western Europe last summer, it pro- duced the deadliest flood on European territory in the last two decades. Beyond record-setting rainfall over countries such as Luxembourg, Switzerland, France and the Netherlands from the storm's "Bernd" low pressure system, more than 230 people were killed in Germany and Belgium. The storm system also caused over an estimated $20 billion (€17.7 billion) of damage. A team from the Geotechnical Extreme Events Reconnaissance (GEER) Association, supported by the National Science Foundation, was mobilized to investigate the potential impacts of the widespread flooding in Germany, Belgium and the Netherlands. Members of the DFI Europe regional chapter closely collaborated with the U.S.-based GEER team and many other engineers and scientists in Europe to collect perishable data and study flooding effects and the event's resulting impacts on geostructures, such as bridges, retaining walls, dikes and embankments. This article features some of the vast information collected by the team, which has recently been published in a comprehensive reconnaissance report and made available for free at geerassociation.org. All data will also be accessible at the NEHRI DesignSafe Cl data repository.

Feb 1, 2022

By J. T. Collins, C. J. Cloete

Secunda Collieries forms part of Sasol Coal, the coal division of the Sasol Group of companies, and already produces 29 Mt of coal per annum from its four collieries: Twistdraai, Brandspruit, Bosjesspruit, and Middelbult. The successful establishment of this mining complex was achieved only through a unique team spirit in which the central services and the decentralized teams under the leadership of the mine management of each of the four mines played an important role. The Secunda mining complex has now reached the optimization phase, during which the mining cost, productivity, safety, and quality of work become as important as production. The setting of priorities and problem solving over the long, medium, and short term are essential for improving the performance of the four collieries. Management had to adapt to the fast-changing environment during the enormously fast build-up of production. The major challenges in the environment were posed by the frequent dolerite intrusions, the extremely hard cutting conditions caused by carbonated nodules and thin sandstone intrusions in the coal seam, and excessive roof and face pressure in some areas due to semi-massive sandstone formations in the rock strata.

Jan 1, 1986

POSITIONS VACANT (Under this heading will he published notes sent to the Secretary of the Institute by members or other persons.) Mine and mill accountant for Mexico. Knowledge of Spanish desirable. Salary $150 to $200 gold per month with living quarters. No. 60. Master mechanic familiar with mine and cyanide plant machinery for Mexico, $200 gold per month and living quarters. No. 61. Electro-metallurgist for production of ferro-alloys, salary $200 to $400 depending on experience. No. 62. Man familiar with ferro-tungsten products of electric furnaces to draw up specifications for machine tools, to watch these tools in service and revise specifications accordingly. Salary $150 to $200 per month. No. 63. Man to take entire charge of the sales of a steel company making electric alloy steels in the shape of ingots, billets and bars. To the right man an opportunity will be offered for taking a leading position in the management of the company and of participating in its results. No. 68. Chemist wanted by Electric Steel concern in the East. Must be fully acquainted with alloy steel analysis. Send full particulars and references. No. 73.

Jan 3, 1916

The annual report f the Secretary of the Navy for the fiscal year, ending June 30, 1917, but including operations and recommendations up to Dec. 1 of that year, contains the following remark about the activities of the Naval Consulting Board. The members of the Institute who are members f this Board are William L. Saunders, Benjamin B. Thayer, Thomas A. Edison, Thomas Robins, Lawrence Addicks, Joseph W. Richards, W. R. Whitney, assisted by 47 other members f the Institute, in the capacity of associate members of the Naval Consulting Board. During the year, the work of this board, organized and approved by Congress in 1915, has increased very materially in importance and volume, its meetings have been frequent and the work of its individual members has been such in some cases as to occupy almost their entire time in the service of the Government. Some time before the active entry of this country into war the board called a special meeting to which were invited some 50 of the leading scientists and industrial managers, whose special study fitted them to advise on the methods of meeting the

Jan 2, 1918

By B. C. Tripathy

The effects of alkali metal ions Li+, Na+, K+and transition metal ions Cr3+ and Mo6+ on the cathodic current efficiency, deposit quality, crystallographic orientations, deposit morphology and polarisation behaviour of the cathode during nickel electrocrystallisation on stainless steel substrate from aqueous sulphate solutions containing boric acid were investigated. The alkali metal ions had virtually no effect on the cathodic current efficiency, deposit quality, crystallographic orientations, deposit morphology and cathodic polarisation. On the other hand, there were significant variations in the current efficiency and deposit characteristics when Cr3+or Mo6+ were present in the electrolyte. Current efficiency decreased by more than 10% even at lower concentrations (> 100 mg/L). Similarly purity of the deposits was affected by the presence of either of the metal ions. In the presence of Cr3+, there was progressive shifting of the nucleation potential of nickel towards more negative values, whereas, in the case of Mo6+the nucleation potential shifted initially towards positive values in the concentration range 2-40 mg/L, but then towards negative values when its concentration exceeded 40 mg/L.

Jan 1, 2003

Chief Geologist, Groundwater and Engineering Geology Branch South Australian Department of Mines and Energy The six papers submitted for consideration during this session include two dealing with techniques for measing rock mass behaviour, including permeability, in boreholes, one describing the use of surface geophysical methods to delineate pollution plumes in groundwater together with analytical modelling of the plume, and one presenting a biological tracer technique applied to the determination of the origin of water entering underground mine workings. A paper describing dewatering at a base metal mine in Queensland includes an account of the investigation techniques employed to establish a conceptual model as a basis for the evaluation of various dewatering strategies. Of considerable interest is the use of a field gravity survey to delineate a zone of highly weathered rock which forms the major aquifer at the site.

Jan 1, 1988