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By O. C. Wheeler

In past years the exploration of the oil possibilities of Colombia has been confined to parts of three distinct physiographic provinces; namely, the coastal plains area near the Caribbean Sea, the Magdalena Valley and the upper reaches of the Maracaibo Basin near the Venezuelan border. During 1935, little exploratory work and no drilling was carried on on the coast, but there was considerable activity in the other two areas. In the Magdalena Valley, the Tropical Oil Co. continued its producing and development operations on the De Mares Concession. The Socony-Vacuum exercised the option it acquired in 1934 on Sr. Luciano Restrepo's concession adjacent to the Tropical property and north of the Sogamoso River. No wells have been started on the Socony's lands although, according to the terms of the lease, drilling must be started within the next two years. West of the Carare River and adjacent to the Tropical's southwestern boundary, the Sociedad Nacional del Carare denounced the lands formerly held by the Union Colombiana, whose lease automatically lapsed during the year owing to the company's failure to comply with its drilling obligations. In the same area, the concessions held by Callejas et al. and the Société Européene des Pétroles are also understood to have lapsed for the same reason. Holdings of other interests in the Magdalena Valley were inactive during the year. Near the upper part of the Maracaibo Basin, the Gulf, through its subsidiary the Colombian Petroleum Co., continued active exploration and development on its Barco concession. Colombian Petroleum Co.—The following information and that presented in the accompanying tables relating to the activities of the Colombian Petroleum Co. was supplied through the courtesy of Mr. E. S. Bleecker, chief geologist of that company. Four wells were completed during the year on the north Petrolea dome, where an attempt is being made to define the limits of the field. On the south end of the Petrolea anticline, one well, Petrolea No. 3, which might be classed as a wildcat, encountered a heavy flow of salt water immediately below the oil zone and had to be abandoned. A second location has been made 1 miles south of No. 3 and somewhat higher on

Jan 1, 1936

By Ralph Nichols

The mines are near the town of Gilmore, in the Texas mining district. This district was organized in 1880. The present producing mines are near the terminus of the Gilmore & Pittsburg railroad. This railroad connects with the main line of the Oregon Short Line at Armstead, Mont. The distance from Gilmore to Armstead is 70 miles. The town of Gilmore is near the head of the Lemhi river at an elevation of 7,000 ft., while the mines are from 400 to 1,300 ft. higher. The range of mountains upon which the mines are situated forms the water shed for the Little Lost river on the west and the Lemhi river on the east. The winters are severe and the snow fall is heavy, but the mines ship right through the year. There is an abundance of timber suitable for all mining purposes in the immediate vicinity. Water is piped into the camp from a lake about 2.5 miles distant. This lake is about 1,400 ft. above the town of Gilmore. The water is exceptionally good for boiler and domestic purposes. The mining companies now producing are the Pittsburg Idaho Co., Ltd.; the Latest Out Mining & Smelting Co., Ltd.; and the Oilmore Mining Co., Ltd. Besides the above propertiea, there are a number of prospects in different stages of development. The producing mines of the district are fissures in limestone, with a general northeast-southwest course and a dip to the west of from 40' to 70°. These fissures are at about right angles to the bedding of the limestones. The veins are regular and the ore shoots strong, both laterally and in depth, so far as developed. The ore shoots have a rake or pitch to the south. The character of the formation is shown in Fig. 1, a section of the Latest Out mine. Character of Ore. The ores of the district are oxidized, carrying an excess of iron over the silica (insoluble matter). The vein filling is a mixture of limonite and hematite, which is replaced by shoots of lead-silver ores. The lead minerals consist of carbonate of lead principally, but with small quantities of sulphide, sulphate, and other lead minerals.

Jan 1, 1914

By O. C. Wheeler

In past years the exploration of the oil possibilities of Colombia has been confined to parts of three distinct physiographic provinces; namely, the coastal plains area near the Caribbean Sea, the Magdalena Valley and the upper reaches of the Maracaibo Basin near the Venezuelan border. During 1935, little exploratory work and no drilling was carried on on the coast, but there was considerable activity in the other two areas. In the Magdalena Valley, the Tropical Oil Co. continued its producing and development operations on the De Mares Concession. The Socony-Vacuum exercised the option it acquired in 1934 on Sr. Luciano Restrepo's concession adjacent to the Tropical property and north of the Sogamoso River. No wells have been started on the Socony's lands although, according to the terms of the lease, drilling must be started within the next two years. West of the Carare River and adjacent to the Tropical's southwestern boundary, the Sociedad Nacional del Carare denounced the lands formerly held by the Union Colombiana, whose lease automatically lapsed during the year owing to the company's failure to comply with its drilling obligations. In the same area, the concessions held by Callejas et al. and the Société Européene des Pétroles are also understood to have lapsed for the same reason. Holdings of other interests in the Magdalena Valley were inactive during the year. Near the upper part of the Maracaibo Basin, the Gulf, through its subsidiary the Colombian Petroleum Co., continued active exploration and development on its Barco concession. Colombian Petroleum Co.—The following information and that presented in the accompanying tables relating to the activities of the Colombian Petroleum Co. was supplied through the courtesy of Mr. E. S. Bleecker, chief geologist of that company. Four wells were completed during the year on the north Petrolea dome, where an attempt is being made to define the limits of the field. On the south end of the Petrolea anticline, one well, Petrolea No. 3, which might be classed as a wildcat, encountered a heavy flow of salt water immediately below the oil zone and had to be abandoned. A second location has been made 1 miles south of No. 3 and somewhat higher on

Jan 1, 1936

By W. F. Boericke

The character of the Wisconsin orebodies must be clearly understood to appreciate the difficulties encountered in sampling and estimating them. Unlike the western vein deposits, they do not lie between regular walls, but form large, often highly irregular bodies, on a single floor in the so-called Galena limestone. The bottom of the ore is nearly always on the clay bed (a flat generally well-defined clay seam a few inches thick) which marks the junction of the base of the Galena lime and the top of the next formation, the Trenton lime. Above the clay bed, the orebodies make the unique pitch and flat formation described by Chamberlin.' Theoretically, we should find two pitches, one on either side of the top crevice, diverging as they go down, with the final flats a considerable distance apart on the clay bed. The area between, known locally as core ground, should thus constitute a single defined orebody, with the richer portions near the pitches and the leaner portion in the center of the core. Practically, we find few examples of this perfect orebody. Almost invariably one pitch is better defined than the other, and often the opposite pitch is marked only by a faint line of fracture showing stronger mineralization than the wall rock, or it may be totally lacking. But with an orebody of any size or richness, at least one strong pitch usually tends to follow an east-west trend, or a quartering course. Late mining developments in the rich New Diggings field indicate that these pitches often assume a horseshoe or crescent shape, the richer ore being in the heart of the crescent and the pitches showing less mineralization as they extend outwards. In the northern end of the field, on the contrary, the pitches maintain generally a consistent direction, and have been mined for thousands of feet from the shaft. The length of the orebody may be several thousand feet, the height varying from 10 to 60 ft. and the width from 60 to 250 ft. In fact, on the core side, there is no definite end to the ore. The mineralization simply gets thinner and thinner, and the limit of working depends on the cost sheet and the profit from the recovery.

Jan 1, 1923

By W. F. Boericke

The character of the Wisconsin orebodies must be clearly understood to appreciate the difficulties encountered in sampling and estimating them. Unlike the western vein deposits, they do not lie between regular walls, but form large, often highly irregular bodies, on a single floor in the so-called Galena limestone. The bottom of the ore is nearly always on the clay bed (a flat generally well-defined clay seam a few inches thick) which marks the junction of the base of the Galena lime and the top of the next formation, the Trenton lime. Above the clay bed, the orebodies make the unique pitch and flat formation described by Chamberlin.' Theoretically, we should find two pitches, one on either side of the top crevice, diverging as they go down, with the final flats a considerable distance apart on the clay bed. The area between, known locally as core ground, should thus constitute a single defined orebody, with the richer portions near the pitches and the leaner portion in the center of the core. Practically, we find few examples of this perfect orebody. Almost invariably one pitch is better defined than the other, and often the opposite pitch is marked only by a faint line of fracture showing stronger mineralization than the wall rock, or it may be totally lacking. But with an orebody of any size or richness, at least one strong pitch usually tends to follow an east-west trend, or a quartering course. Late mining developments in the rich New Diggings field indicate that these pitches often assume a horseshoe or crescent shape, the richer ore being in the heart of the crescent and the pitches showing less mineralization as they extend outwards. In the northern end of the field, on the contrary, the pitches maintain generally a consistent direction, and have been mined for thousands of feet from the shaft. The length of the orebody may be several thousand feet, the height varying from 10 to 60 ft. and the width from 60 to 250 ft. In fact, on the core side, there is no definite end to the ore. The mineralization simply gets thinner and thinner, and the limit of working depends on the cost sheet and the profit from the recovery.

Jan 1, 1923

By C. V. Millikan, C. V. Sidwell

There is nothing more important in petroleum engineering than a definite knowledge of the pressure at the bottom of an oil well at any existing operating condition, and the relation of this pressure to the pressure within the producing formation. A knowledge of bottom-hole pressures is fundamental in determining the most efficient methods of recovery and the most efficient lifting procedure, yet there is less information about these pressures than about any other part of the general problem of producing oil. Determination of Bottom-hole Pressures Bottom-hole pressure may be calculated or determined by several methods. On an inactive well it may be calculated from the fluid head or, if the well is shut in, by adding the casinghead pressure, the static head of the gas and the fluid head. In wells flowing naturally through tubing the pressure at the bottom of the tubing may be calculated by adding the pressure at the casinghead between the tubing and the casing and the pressure due to the weight of the column of gas, but there is always possibility of error caused by fluid being in the annular space above the bottom of the tubing. If a well with tubing is flowing through either the annular space or the tubing, sufficient gas may be injected through the static space to insure that it is free of fluid but not sufficient to establish an appreciable friction loss. The pressure at the bottom of the tubing can then be calculated by adding to the pressure at the tubing head the pressure due to the weight of the column of gas. This is probably the most accurate method of calculating bottom-hole pressures. In wells flowing by gas-lift, the pressure at the point the gas enters the flow may be calculated by a gas-flow formula. Several types of pressure bombs have been used to measure the pressure at the bottom of wells. One is a piece of steel tubing with a check valve in the bottom and a connection for a pressure gage at the top. It is lowered into the well to the point at which the pressure is

Jan 1, 1931

By L. R. Raymond

With the trend toward deeper and consequently hotter holes, measurements of drilling mud properties at atmospheric temperatures are becoming increasingly inadequate.' Both the prediction and control of down-hole mud properties depend in part upon our knowledge of temperatures in the wellbore. Consequently, a better understanding of factors that affect temperatures during circulation and trips could improve drilling operations. It was toward the goal of obtaining this understanding that this study was directed. Other investigators2 have studied the response of fluid temperature in the borehole during trips. However, all of these studies have used an assumed formation temperature profile at the conclusion of circulation and have provided no means to calculate this profile directly. In this study, the formation profile during circulation was calculated. Other investiga-tors3-5 have also studied bottom-hole temperature during circulation. However, they have developed neither general techniques for calculating the entire temperature profile in the system nor generalized methods for predicting bottom-hole fluid temperatures during circulation. Such techniques and methods have been developed and are discussed briefly in the following pages. Temperature Behavior During Circulation Circulation of fluid during the drilling operation is represented schematically in Fig. 1. The process of circulation has three distinct phases: (1) fluid enters the drill pipe at the surface and passes down the drill pipe; (2) fluid exits the drill pipe through the bit and enters the annulus at the bottom; and (3) fluid passes up the annulus and exits the annulus at the surface. To simulate the thermal behavior of the fluid in the system, each of the phases of circulation must be described mathematically. In Phase 1, the fluid enters the drill pipe at a specified temperature, TDo. As the fluid passes down the pipe, its temperature is determined by the rate of heat convection down the drill pipe, the rate of heat exchange between the drill pipe and the annulus, and time. Phase 2 of the circulating process merely requires that the fluid temperature at the exit of the drill pipe be the same as the fluid temperature at the entrance of the annulus; i.e., TD(L,t) = TA(L,l). Thus in Phase 3, the fluid enters the annulus at TD(L, t). As the fluid flows up the annulus, its temperature is determined by the rate of heat convection up the annulus, the rate of heat exchange between the annulus and the drill pipe, the rate of heat exchange between the formation adjacent to the annulus and the fluid in the annulus, and time. These rates of heat exchange and the time dependency of mud temperature are described by well known heat-flow equation.6 Consequently, as shown in the Appendix, the temperature profiles in the drill pipe, annulus, and formation can be obtained by solving Eqs. 1 through

Jan 1, 1970

By Filippo Mira-Cattò, Andrea M. R. Pettinaroli, Elena Rovetto

"The construction of Powisle station of Metro Warsaw Line 2, in Poland, required the execution of two shafts next to an urban road tunnel adjacent to the Vistula River. The shafts were linked by three conventionally mined tunnels to be excavated 10 m below the water table level, into an upper sandy and sandy silty layer and a lower stiff clayey stratum. After a failed dig attempt under the protection of jet grouting and forepoling, it was decided to deal with the tunnels excavation problem by using the ground freezing technique as a temporary, non-polluting geotechnical treatment, keeping in service the upper road tunnel. The planning of the activities and the executive phases had a significant importance for the success of the work. For work scheduling reasons the mixed system was adopted, i.e. using both the liquid nitrogen system and the brine freezing method. The freezing process management, with a real time evaluation of the soil temperature measured by thermometric strings and an accurate monitoring of the overlying road tunnel structure, allowed the tunnel excavation and lining stages to be performed under difficult conditions, without water leaking from the frozen ground shell, within the expected times and saving extra costs.INTRODUCTIONThe new Underground Line 2 in Warsaw connects the eastern and western part of the town. One of the most critical interferences was the under passing of the Vistula river and of the Wislostrada motorway tunnel, a very congested motorway along the western bank of the river, with the construction of the new station Powisle. The construction of the station required the excavation of two shafts, using the top-down system with the creation of intermediate slabs while deepening the excavation.The shafts were used for the extraction of four Tunnel Boring Machines (TBMs), two approaching from the Vistula river side (east-side) and two approaching from downtown (west-side); in order to connect the two shafts was foreseen the realization of three tunnels, two for the underground lines and the central one for the exchanging passenger platform. These tunnels were underpassing the “Wislostrada Road Tunnel” and interfered with this tunnel foundation, which consisted of diaphragm walls (DW), the “barrettes” (Figure 1).Due to the variable geological conditions at the site, the first excavation stage, with a temporary underground support constructed of horizontal jet grouting columns and forepoling, caused the North tunnel face failure, that required an immediate filling of the empty cavities with lean mix concrete under the Wislostrada tunnel slabs. Thereafter, the recovering attempt with the grout injections could not be completed because of the development of heaves induced on the tunnel structures (Bringiotti et al. 2016). In those conditions the tunnel excavation with traditional technologies appeared to be very problematic, with high risk for the structural safety of the Wislostrada tunnel. This would have meant longer duration for the works and higher costs for the General Contractor as well as for the city Council."

Jan 1, 2015

By Thomas C. Atchison

The purpose of this Bureau of Mines investigation was to measure the amplitude and shape of the strain pulse and the size of the crushed zone produced in a granite by different explosives and to determine how these quantities are related to the detonation properties of the explosives. The reflection theory of rock breakage has shown that the amplitude and shape of the strain pulse incident at a free surface determine the fragmentation and volume of rock broken. Determination of the properties of an explosive that control the characteristics of the strain pulse produced in the rock will help in evaluating explosives for use in blasting. The investigation showed the different explosives produced a twofold variation in the amplitude of the strain pulse but little variation in the shape of the pulse. The explosives also produced a twofold variation in the volume of the crushed zone, but differences among the explosives were more accurately determined by strain-amplitude measurements than by crushed-zone measurements. The peak amplitude of the strain pulse and the volume of the crushed zone correlated with the calculated detonation pressure of the explosive.

Jan 1, 1959

By Sherman L. Pease

An inexpensive and relatively rapid method that can be used by field crews is described. Fluid movement is determined by releasing a tracer (dye) in the well at a predetermined level and, after an interval of time, sampling the well fluid at another level. The testing equipment consists of a combined crusher and sampler unit that is run into the well on a wire line. The rate of movement can be calculated from time-volume relationships. Description of Method It is often desirable to determine whether there is occurring any transfer of fluid from point to point in a shut-in well, and, if so, to measure the rate of movement. When it is desired to examine a large number of wells for possible "thief" sands, the time and expense will be considerable unless the method used is inexpensive and rapid. After experimentation with several possible solutions to the problem, the Production Department of the Shell Oil Co., Inc., developed the apparatus described herein, which has proved satisfactory. Routine operations with it can be carried out by field production crews with a minimum of technical supervision and with negligible investment in equipment. The method is based upon releasing a suitable tracer in the well fluid at a known level, and recovering a sample of well fluid at another level after a measured interval of time. Repetition of this process with different time intervals between release and sampling gives the necessary data. For purposes of illustration, the setup for measuring migration of fluid in an upward direction is described in the following paragraphs. The arrangement of equipment is shown diagrammatically on Fig. I. The elements of the combination unit are the tailpiece, the crushing device, the spacer and the sampling device. The lengths of the tailpiece and spacer are varied to place the crushing and sampling devices in the desired positions in relation to the sands being tested. The crushing device breaks the glass bottle containing the tracer when the tailpiece strikes the bottom of the well and the tension on the sand line is slackened. Because of the open construction of the crushing device, the tracer is quickly and completely disseminated in the well fluid. The sampling device is a suction bailer, which obtains a sample of the fluid surrounding the perforated nipple just before the unit is picked up off bottom. The sample is retained in the barrel by the ball valve for examination at the surface. Normally, on the first run into a well, the sample is obtained near the releasing point of the tracer, and thereafter samples are taken near the base of the upper sand if migration is indicated by the dilution or absence of the tracer in the initial sample. The length of the time interval between the releasing of the tracer and the sampling of the well fluid is varied for successive runs, attempting first to establish the rate within limits and then to define it more accurately by additional runs if necessary.

Jan 1, 1946

By Sherman L. Pease

An inexpensive and relatively rapid method that can be used by field crews is described. Fluid movement is determined by releasing a tracer (dye) in the well at a predetermined level and, after an interval of time, sampling the well fluid at another level. The testing equipment consists of a combined crusher and sampler unit that is run into the well on a wire line. The rate of movement can be calculated from time-volume relationships. Description of Method It is often desirable to determine whether there is occurring any transfer of fluid from point to point in a shut-in well, and, if so, to measure the rate of movement. When it is desired to examine a large number of wells for possible "thief" sands, the time and expense will be considerable unless the method used is inexpensive and rapid. After experimentation with several possible solutions to the problem, the Production Department of the Shell Oil Co., Inc., developed the apparatus described herein, which has proved satisfactory. Routine operations with it can be carried out by field production crews with a minimum of technical supervision and with negligible investment in equipment. The method is based upon releasing a suitable tracer in the well fluid at a known level, and recovering a sample of well fluid at another level after a measured interval of time. Repetition of this process with different time intervals between release and sampling gives the necessary data. For purposes of illustration, the setup for measuring migration of fluid in an upward direction is described in the following paragraphs. The arrangement of equipment is shown diagrammatically on Fig. I. The elements of the combination unit are the tailpiece, the crushing device, the spacer and the sampling device. The lengths of the tailpiece and spacer are varied to place the crushing and sampling devices in the desired positions in relation to the sands being tested. The crushing device breaks the glass bottle containing the tracer when the tailpiece strikes the bottom of the well and the tension on the sand line is slackened. Because of the open construction of the crushing device, the tracer is quickly and completely disseminated in the well fluid. The sampling device is a suction bailer, which obtains a sample of the fluid surrounding the perforated nipple just before the unit is picked up off bottom. The sample is retained in the barrel by the ball valve for examination at the surface. Normally, on the first run into a well, the sample is obtained near the releasing point of the tracer, and thereafter samples are taken near the base of the upper sand if migration is indicated by the dilution or absence of the tracer in the initial sample. The length of the time interval between the releasing of the tracer and the sampling of the well fluid is varied for successive runs, attempting first to establish the rate within limits and then to define it more accurately by additional runs if necessary.

Jan 1, 1946

By Luis Henrique Torres Dantas, Maycon Athayde, Rossano Augusto Pilon Nunes

The objective of this work is to evaluate the physical quality achieved in the iron ore pellets and the temperature profile in the pellet bed by applying an inversion in the flow during the cooling. The firing of pellets requires a minimum residence time in the sintering temperatures of the hematite grains [1]. The applied concept aims at raising this time to pellets located at the bottom of the bed which would provide an improvement in the physical quality of the product. The tests were carried out in a pot-grate type oven and the samples of fired pellets were divided into three aliquots according to the loading position of the pot termed top, middle and bottom, the pellets were sieved and subjected to physical tests and the compared to conventional indurating flow with the same ores and inputs. It was possible to show an increase of 7 to 8% in the compressive strength of the medium and bottom layers, maintaining the top layer results. The objectives of the research were achieved and the tests will be extended to assess the impacts on the mass and energy balance of the indurating machine and its components.

Oct 1, 2019

The visit which took place on the 18th February, 1972 was a departure in that the places visited had no direct connection with the work in which members of the Institute are normally engaged. It was refreshing and stimulating to see important and involved operations normally outside ones own trend of life and to have experts to speak about technical, financial and matters of general interest concerning their work, not forgetting their troubles and problems and how they overcame them. Carlton Centre The members of the Institute were received by Mr D. Appleton, Public Relations Officer of the Carlton Centre Limited, who introduced Mr L. R. M. Fee of W. Rhodes Harrison, Architect in charge of the project; Mr W. C. E. Skilton of Murray and Roberts, the Engineer in charge of the construction of the complex and Mr A. Home the Senior Operating Engineer of Carlton Centre Limited. Each of these gentlemen addressed the members giving short rundowns on the project with special reference to their particular sphere of the undertaking. A variety of particularly interesting statistics relating to the planning construction and the ultimate operation and maintenance of the complex was given. Mining engineers present had an opportunity to compare the problems encountered by them associated with depth to problems encountered by the civil engineer in the construction of a building rising to such an enormous height. To some of the members a sense of similarity of the labour problems encountered must have been recognised. After tea the visitors were divided into groups, each under the guidance of an official, and then visited the highest floor accessible and thereafter the 19th floor where the internal arrangements for airconditioning, lighting, plumbing, power supply and communication arrangements were explained. Thereafter a visit to one of the seven basements which houses all machinery required to serve this enormous complex enabled the visitors to see the standby power arrangements as well as the refrigeration plant. The visit finished in time to proceed to the Crest Hotel in Hillbrow for lunch. To our hosts for the visit to the Carlton Complex a special vote of thanks is recorded. Strydom Tower In the afternoon the party proceeded to the Strydom Tower where Mr Knight from the Public Works Department who was the Engineer in charge of the construction of the tower gave details on the construction and the extraordinary methods which had to be adopted to achieve the desired objectives and to overcome known as well as unforeseen difficulties. The comparatively short time taken to complete the project and the good safety record appeared to impress the visitors. The final phase of the visit was taken care of by Mr Bothma of Telecommunications Department of the Post Office, who gave an extremely interesting explanation of the telecommunication organization of the Post Office with particular reference to the part the Hillbrow Tower plays in the South African telecommunication system. Both gentlemen answered many questions willingly and interestingly. Following the explanatory talks the visitors were shown the technical equipment housed in the two top levels of the tower. Short explanatory talks gave members an insight into the workings of one of the most important aspects of modern life. Even to the amateur photographer opportunities existed to view and photograph the city from the highest available observation point. We are indebted to Mr Gouws, the Regional Director of the Post Office for granting permission to visit sections of the tower normally not accessible to the general public and to our hosts for the manner in which we were received and entertained on the explanation of the many interesting features of this important installation. In conclusion, the programme for the day can be classified as interesting, of exceptional educational value, and an opportunity to see something of the engineering skills put into two vast and ambitious undertakings and the results achieved.

By I A. Lamb

The Melbourne City Link Project has two tunnels, the Domain and Burnley Tunnels, which have been constructed by Transfield Obayashi Joint Venture (TOJV) under a design and construct contract. The two tunnels are located essentially under the Kings Domain, the Yarra River and, in the case of the longer Burnley Tunnel, under the inner suburb of Richmond. The Burnley Tunnel is 3.5 km long and reaches a depth of 65 m at the central Swan Street Shaft, the invert being at RL -60 m. The Domain Tunnel is 1.6 km long, with the invert reaching RL -20. The tunnels were driven, for the most part, in the siltstone and sandstone of the Silurian Age Melbourne Formation. Construction aspects of the driven tunnels as related to the engineering geology have been described by Hutchison et al (1998). The Silurian bedrock is a fractured rock aquifer that is connected to overlying alluvial aquifers. Excavation of the tunnels allowed temporary groundwater inflows which substantially de-pressurised portions of the various aquifers. This de-pressurisation provided the potential to accelerate on-going secondary consolidation rates of the Holocene Aged Coode Island Silt (CIS) and the older Quaternary Fishermens Bend Silt (FBS) deposits, in areas where these materials directly overly the aquifers. As a large portion of the urban area of South Melbourne and the old river course of the Yarra River contain extensive CIS deposits, and were within the drawdown influence of the tunnels, the management of the hydrogeological regime was very important. The permanent design of the tunnels comprised drained and undrained sections (a partially tanked design) which, along with some permanent recharge, provide long-term protection against the possibility of accelerated settlement rates. During construction TOJV implemented a comprehensive groundwater management plan to deal with issues related to the temporary drawdown of the aquifers and the temporary acceleration of settlement. This paper describes the hydrogeological regime, the effects of the tunnelling, the monitoring programs, the extensive temporary recharge system, and the consultation program that TOJV utilised to manage the hydrogeological issues.

Jan 1, 1999

By Kaige Zheng, Hongwei Wang, Tong Wang, Yanjun Li, Yongping Wu, JIANQIANG JIAO, Baolin Jiang

Due to the influence of economic development on the demand growth of coal resources, many mines in China have gradually entered deep mining. When the roof of deep coal seam is hard rock, it is easy to cause strong ground pressure with the advance of the working face, which seriously threatens the safety of coal mining. Taking 31,104 working face of a mine as the engineering background, this paper studies and compares the deformation characteristics and stress transfer evolution law before and after the presplitting of the hard roof through the combination of physical similarity simulation, numerical calculation, and field measurement, based on the analysis of the interaction relationship between the breaking and collapse of the composite hard roof, and verifies the treatment effect of hydraulic presplitting through field measurement. The results show that: (1) In the early stage of mining under the composite hard roof, the lower roof is mainly subjected to tensile failure, the voussoir beam structure formed is relatively unstable, and the stope is prone to impact. When the mining distance of the working face is large, the breaking rotation of the upper hard roof voussoir beam causes pressure damage to the lower hard roof, causing the lower hard roof voussoir beam structure to slide and lose stability, resulting in strong ground pressure in the working face. (2) After presplitting of composite hard rock stratum, in the early stage of mining, the range and degree of rock stratum damaged by presplitting are small except for the hard rock stratum itself, and the presplitting effect is not significant. When mining to the first square position, the roof is damaged in advance by presplitting, the overall plastic damage range increases, the damage form area increases, and the damage degree deepens. The vertical displacement of the composite hard roof increases rapidly, and the presplitting effect is remarkable. (3) The evolution characteristics of roof principal stress transfer show that under the dual effects of mining and presplitting, the roof tensile stress area above the goaf is large, the rock failure horizon rises, and the roof failure height is high and the failure degree is deep. The stress concentration degree of the coal mass in front of the goaf is reduced, and the stress concentration range is transferred to the rock mass in front. With the advance of mining, the hard roof in front can break and caving in time, so as to avoid rock burst disaster caused by large suspended roof area. The field ground pressure monitoring shows that the average periodic weighting interval, weighting range, peak value before weighting, and peak value during weighting of the working face after presplitting decrease by 53.5%, 38.03%, 8.63%, and 5.96%, respectively, which effectively reduces the weighting intensity and ensures the safe and efficient mining of the working face.

May 16, 2023

By H. F. JR. Miller

(Butte Meeting, August, 1913.) THE major cause of the deterioration of the open-hearth furnace as its length of service increases, is the melting down, or rather the slagging, of the checker-brick, together with the deposition of dirt in the form of iron oxide, etc., which helps to close the openings, as well as to slag the brick by chemical action. Any construction that will do away with the necessity of having the waste gases come down through the checkers will eliminate the main reason for their deterioration. There are some other well-defined reasons which are subordinate to the main one given above. Some of the defects of the present type of regenerator chambers are as follows: 1. The checkers cannot be cleaned while the furnace is in operation, nor can they be cleaned at the end of the run without taking out all of the checker-brick. This causes high costs for labor and brick. The labor cost is high because all checker-brick have to be handled twice. The brick cost is high because many of the bricks are spalled in the double handling, rendering them useless because a spalled brick will not stand up. 2. The top courses of brick become coated with iron oxide, etc., melt clown, and large amounts of dirt are deposited throughout the checkers, especially at the bottom. The draft of the furnace is decreased by the closing of the top and bottom openings, especially the top ones, and the entire working of the furnace is affected. If an effort is made to clean the checkers the dirt and brick falling down into the holes still further diminish the draft. 3. The distribution of the air or waste gases through the checkers is in many cases uneven, resulting in a lower temperature of pre-heated air and therefore a slower working furnace. Also, the passage of air and waste gases is so crooked that sometimes the chimney is not powerful enough to overcome the friction.

Jan 6, 1913

By AIME AIME

Russell B. Paul, Chairman of the Special Committee on Divisional Relationships, presented the interim report of his Committee which was published in the September, 1945, issue of MINING AND METALLURGY and a copy of which is incorporated in the official minutes of this meeting. The following specific actions were taken by the Board of Directors in relation to the six recommendations in the Summary of the Report as published: (1) Mr. Haider, Chairman of the Petroleum Division, presented the formal request of his Executive Committee that the headquarters of the new Secretary of the Petroleum Division be established in Dallas, Texas. After lengthy discussion in which the point was made that the success of this program would depend upon effective co-operation between the Chairman of the Division, the Secretary of the Petroleum Division, and the Secretary of the Institute, the request was approved. The new secretary will be selected by the Division and will be employed by the Institute in the capacity of an Assistant Secretary. (2) The following item in the report was approved:

Jan 1, 1945

By J. T. I. Poijärvi

The smelter off-gas cleaning and the weak acid treatment at Outokumpu Harjavalta Metals Oy are presented and described in this paper. The smelter consists of the copper and nickel smelters and the acid plant of three separate acid plants two of which are double contact and one single plant and of one liquid sulphur dioxide plant. The preliminary cooling and flue dust separation of the smelter off....,gases from the copper ?and nickel flash smelting furnaces and converters? in the waste heat boilers and in the hot electrostatic precipitators are described. The final cooling and cleaning of the gases in the scrubbers at the sulphuric acid plant and the treatment of the weak acid in the vacuum and in the submerged combustion evaporators for the removal of impurities are presented as well as the treatment of the condensates from the evaporators. The attention is paid to the generation of sulphur trioxide in the smelter off-gas.and to the treatment of that in the weak acid bleed-off and to the utilization of the treated acid.

Jan 1, 1992

By J. T. I. Poijärvi

The smelter off-gas cleaning and the weak acid treatment at Outokumpu Harjavalta Metals Oy are presented and described in this paper. The smelter consists of the copper and nickel smelters and the acid plant of three separate acid plants two of which are double contact and one single plant and of one liquid sulphur dioxide plant. The preliminary cooling and flue dust separation of the smelter off-gases from the copper and nickel flash smelting furnaces and converters in the waste heat boilers and in the hot electrostatic precipitators are described. The final cooling and cleaning of the gases in the scrubbers at the sulphuric acid plant and the treatment of the weak acid in the vacuum and in the submerged combustion evaporators for the removal of impurities are pre¬sented as well as the treatment of the condensates from the evaporators. The attention is paid to the generation of sulphur trioxide in the smelter off-gas and to the treatment of that in the weak acid bleed-off and to the utilization of the treated acid.

Jan 1, 1992

Meeting of Sept. 25, 1914.-The Committees to have charge of the arrangements for the Annual Meeting in New York, Feb. 15 to 18, 1914, were appointed. It was voted that the Secretary of the Institute take up with the Chairmen of the Local Sections the question of arranging for the transportation to the meetings of the Institute of the members of the respective sections. The Board of Directors unanimously voted to extend to each and all of the members of the Local Committees of the Salt Lake Meeting its hearty thanks for their efforts which resulted in the very successful meeting. The President was authorized to sign the letter to the President of the United States in regard to the appointment of some representative of the mineral industry upon the Federal Trade Commission. An appropriation of $250 was granted to the Southern California Local Section. The By-Laws of the Utah Local Section were approved. Upon recommendation of the Committee on Membership, 133 members, 7 associates and 13 juniors were elected to membership. BRADLEY STOUGHTON, Secretary.

Jan 11, 1914