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By Maurice Grieves

GC. Waterman Mr. Grieves' paper on "Shaft Sinking Today--A Boring Business Tomorrow" in the Dec. 1981 issue of MINING ENGINEERING is an excellent description of recent improvements in speed and costs of shaft sinking. However, shaft boring techniques are not a recent development. In 1935-36, the Idaho Maryland Co. (gold), Grass Valley, CA, bored the vertical 1.5-m-diam Idaho No. 2 ventilation and supply shaft to a depth of 346 m. The equipment was designed and perfected by Branner Newsome and was, I believe, described in "Transactions." Pickands Mather later bored a 1.8-m-diam shaft to a depth of about 305 m using Newsome's design. The Idaho No. 2 shaft cut through hard gabbro, diabase dikes, soft serpentine, very incompetent ankeritized serpentine and a strong fault zone. The completed shaft did not require timber support; the fault zone was cemented. Equipment consisted of a rotating 1.5-m or 3-m core barrel with a slotted bottom which cut a 76-mm kerf. The cutting agent was chilled steel shot introduced into the slot as needed. The driving mechanism and core barrel were lowered into the shaft, the former secured to the wall and the inshaft "engineer" operated the motors which controlled core barrel rpm and advance. After an advance of 1.5-3 m the equipment was lifted out of the shaft, a half(?) stick of powder cut off the drilled core, and it was hoisted to the surface with a cable attached to an eye bolt at the tope of the core. A "shift" consisted of three men: hoistman, equipment operator (down the shaft), and a surface laborer. Advance was variable as equipment and techniques were perfected. Near the end of the job advance was, as I remember, 1.5-3 m per shift. Costs were, as I recall, about $115/m. Up to 4 m cores were lifted out in one piece and swung to the dump by a stiff leg derrick. The Newsome equipment was relatively inexpensive to build and operate and his method should be (more than?) competetive with the methods described by Grieves. W.E. Hawes The author, in mentioning the South African developments of the cactus grab, ignores the parallel development of the Cryderman mucker in this hemisphere. Perhaps a slightly longer history of blind hold drilling would have been in order. Blind shaft boring got a major boost at the Nevada Test Site, as part of the nuclear weapons development, when it was essential to be able to quickly assess depth for weapons testing. One of the early civilian attempts to utilize this technology occurred when Kerr McGee drilled the shaft at the Section 19 Mine at Ambrosia Lake, NM. This twin masted drill rig belonged to a subsidiary of Kerr McGee, not Shaft Drillers. This was a difficult hole, due to bentonitic shales that decomposed. Later advances in drilling fluids eliminated this problem. The Conoco project referred to is not entirely correct, and needs minor amplification: The depth of the development (not pilot) shaft drilled was 684 m, at a diameter of 3.05 m, with a 2.16 m ID hydratatic casing being installed to a depth of 669 m. Conoco Inc., not Challenger, executed the drilling, however Conoco did use Challenger Drilling Company's Rig 14-S. Rig 14-S is unique in that it is specifically designed for shaft drilling, rather than being an oil field rig used for this service. All work was planned and directed by Conoco personnel. Deviation of the aforementioned shaft from vertical was 31 cm. Two smaller shafts (pilot shafts) were drilled with the same rig. These smaller ones were drilled 1.8 m in diameter, to depth of 665 m and cased with .91-m-diam casing, to depth of 650 m to be used as pilot holes for 5.5 m diameter shafts. The total elapsed time for all drilling, casing, cementing, and rig moves was 50 weeks. The constraints mentioned of vertical accuracy, torque, wall collapse, rig set up time, lining time etc., pumping out, etc., may not be as serious as the author implies. First, vertical accuracy: The record achieved by Conoco indicates that with reasonable care, good accuracy can be obtained, primarily by having a fair amount of weight in tension, rather than on the drill bit. Second, the amount of torque that can be applied to the drill stem has been greatly increased by the introduction of larger diameter drill stems, such as the new Hughes rig uses. Third, risk of collapse of shaft walls is minimal with the proper mud program. Basically, the walls are supported by the weight of the mud and it is not removed until some type of casing is installed and grouted in. Here in the real challenge of blind drilling shafts to devise a more economical method of lining bored shafts than using steel casing. The remaining issues were minor at Conoco, provided adequate planning and scheduling takes place. An excellent paper, "Shaft Drilling--Crownpoint Project" by Hassell H. Hunter, presented at the Fifth Uranium Symposium in Albuquerque in Sept. 1981 contains details of this project. A combination of blind boring, with enlargement by either mechanical means (boring machine, or tunneling type shield) or slabbing down, with muck removal through a larger bored shaft would seem to be the future trend in shaft development. The economics, especially for wet conditions, favor this concept over conventional sinking, as has been demonstrated at Kerr McGee --Churchrock, UNC--Churchrock and Conoco at Crownpoint.

Jan 3, 1983

By K. Lundholm, M. Andersson, L. Nevatalo, Å. Holmström, L. Hedström

"Several copper deposits have the arsenic bearing minerals enargite (Cu3AsS4) and tennantite (Cu12As4S12). Since this mineral contain both arsenic and copper, it is not possible to remove the arsenic by selective flotation. Partial roasting is a method to clean the concentrate from arsenic and thereby produce a suitable raw material for the copper smelter. Also mercury is commonly found in copper bearing minerals. In the partial roasting process both arsenic and mercury are volatilized, while part of the sulphur is used as energy during the roasting. This gives a calcine suitable as feed to a smelter, much like an ordinary copper concentrate. A typical analysis of calcine would be: S content 18–22%, As content below 0.3%, Cu content – not affected, grain size – not affected. However, if the concentrate contains mercury, the mercury will be volatilized during the roasting process. This will lead to very high mercury contents in the subsequent process of sulphuric acid, unless the SO2-rich process gas is pre-treated by the Boliden/Norzink process that recovers mercury as calomel, Hg2Cl2. The volatilized arsenic in the gas phase can be recovered either by dry or wet methods. However, one problem is that arsenic also contaminates the fine grained calcine dust that is captured downstream in the gas cleaning system. The calcine dust contains valuable metals such as copper, gold and silver that needs to be separated from the arsenic. The ultimate aim is to stabilize the recovered arsenic as a compound with minimum impact on the environment and recover the valuable metals. By using wet recovery methods it is possible to selectively precipitate copper, gold and silver as sulphides while arsenic is kept dissolved in the liquid. The precipitated metal sulphides can be mixed with the calcine and sent to the copper smelter. The dissolved arsenic is sent to effluent treatment and is further treated in Outotec ferric arsenate precipitation process, where arsenic is precipitated as the stable compound basic ferric arsenate, formula FeAsO4·xFe(OH)3. All concentrates containing arsenic are unique and the process design of a roaster plant must be based on relevant process data. The process data is collected during tests in lab scale and pilot scale, where the influence of critical process parameters on the quality of calcine is studied. The ability to run tests both in lab scale and pilot scale is crucial to the development of the correct roasting process. Outotec is well equipped for this."

Jan 1, 2014

By Jozef S. Stachulak

INTRODUCTION Conveyor belt fires represent a serious hazard in underground mines. This fact is well understood in most mining countries. The statistical data for Ontario mines (1) indicates that the majority of the conveyor fires occurred at the head pulley of the conveyor belt. The main emphasis for fire prevention and detection should then be concentrated at the drive pulley of the conveyor designed to transport non-combustible material. In the case of conveyor belt fires, it is of utmost importance to detect the hazard at an early stage, when the overheating has not yet reached the ignition point. Thermal noise detection sensors were installed in 1987 at several conveyor sites at Inco mines. PRODUCTS OF COMBUSTION THERMAL DEGRADATION OF CONVEYOR BELT Various investigations on conveyor belt fire hazards have been made in the past (2, 3, 4, 5, 6, 7). Several belt samples (6, 7) were subjected to thermal oxidative degradation. The belts used in these tests were neoprene, polyvinyl chloride and styrene-butadiene rubber (6). About 70 different compounds were identified in the volatile thermooxidative products. As expected, hydrogen chloride was the major toxic product formed, accompanied by relatively low quantities of other toxic compounds such as carbon dioxide, carbon monoxide, sulfur dioxide, carbon disulfide, hydrogen sulfide, benzene, chloroprene, cresols, chloroethanol, formic acid and C8 hydrocarbons. The research investigation (8) performed by the USBM indicated that "smoldering combustibles generate a very low level of CO compared to the level of smoke produced". The cited publication (8), states that, "During smoldering combustion, typical mine combustibles produce about 2.5 times more smoke than CO. As fires develop to their flaming stages, the trend reverses and about eight times as much CO is produced as smoke." The reader is referred to several significant sources of additional information pertaining to emission products that can be found in references (8), (9), and (10). ANALYSIS OF FIRE HAZARDS U.S.A. AND ENGLAND Nearly 15 percent of all underground coal mine fires in the United States involved ignition of conveyor belts (7). In many cases, the fires propagated through thousands of feet of belt entry and created losses in the millions of dollars. Some of these fires consisted of rubber belts. Some involved polyvinyl chloride and neoprene belts that were classified "fire resistant". Typically, a belt fire begins after the conveyor is stopped. The fire is initiated by burning coal dust and grease accumulation around defective rollers or belt drives that have become heated by friction (7). An analysis of 113 conveyor fires (11) showed that 41 originated at the driving pulleys, 32 at the defective rollers, and 40 elsewhere on the conveyor system. The severity of the fire, which can spread along a conveyor road, has been emphasized by the disaster at Creswell Colliery, Derbyshire, on September 26, 1950, when 80 men were overcome and killed by toxic fumes from the fire (12). The fire started from smoldering caused by friction, and developed into a flaming combustion, propagating along the roadway containing the rubber belt at an estimated speed of 40.2 m/s (90 mph), and travelling a total of 650 m (2100 ft) THE INFLAMMATION OF CONVEYOR BELTS THE MECHANISM OF IGNITION Defective operation of a conveyor belt may start a fire in several ways: - Friction of the belt on the drive pulley. - Jamming of a guide roller, and others.

Jan 1, 1991

By C. Hosten, K. V. S. Sastry, D. J. Kawulok-Englund

Introduction Since the last decade the iron ore processing industry has undergone drastic changes from supplying screened and natural ores to manufacturing tailored concentrates and pellets. Increased need for the beneficiation of lower grade iron ore deposits and the increased demand for higher grade concentrates necessitate finer grinding of iron ores before concentration. The normal filtration stations used in the past are experiencing difficulties in dewatering the finely ground concentrates to moisture levels acceptable for balling. In addition to finer grinding, applications of complex beneficiation techniques has decreased the filterability of the concentrates and create problems in filtration of iron ore concentrates. An overview of the filtration literature indicates there are few research reports on the dewatering of iron ore concentrate slurries. There exists a need to understand the principles and mechanisms involved in the filtration of iron ore concentrate slurries with a goal of developing more efficient filtration techniques. This paper presents the results from the first phase of our research program that included the development of a reproducible benchscale filtration technique and the investigation of the filtration behavior of eight iron ore concentrates.

Jan 10, 1983

By Bruce Haldeman

Timber has been used as pile support for structures for 6,000 years. Some means of preservation of wood go back almost that far. Timber piles support all types of structures ? some are buried below the water table; others raise a home for protection from animals or a chief's home for prestige. Millions of wood piles have been driven for bridge support. Earlier piles were driven by hand then by ingeniously raised weights. Charring, animal fats and oils have been used for preservation. Coal tar creosote and other preservative methods started only in the early 1800's and give effective protection.

Jan 1, 1984

This study relates to continuous face haulage systems in underground coal mines, and was performed by Joy Manufacturing Company for the U. S. Bureau of Mines under the Bureau of Mines Contract No. HO 242025. The effective starting date for this work was June 14, 1974. There were two main reasons for making this study, the first being to find a safer system to move coal away from the face than the currently predominant shuttle car system, and the second being to seek ways to advance the state-of-the-art of continuous face haulage as a means of increasing coal production.

Jan 1, 1975

By Fulvio Tonon

And Rabcewicz said ?tunnels should be driven full face whenever possible.? ADECO, which stands for ?Analysis of Controlled Deformations in tunnels,? now allows us to fulfll Rabcewicz?s dream in any stress-strain condition. In order to achieve that dream and its consequent control over cost and schedule, however, NATM must be abandoned for the ADECO. The paper presents the basic concepts in the ADECO approach to design, construction and monitoring of tunnels together with some case histories, including: full face excavation for Cassia tunnel (width of 22 m, height of 14 m) in sands and silts under 5 m cover below an archeological area in Rome, Italy; Tartaguille tunnel (face area > 100 m2) advanced full face in highly swelling and squeezing ground under 100 m cover where NATM led to catastrophic failure, France; and 80 km of tunnels (face area > 100 m2) advanced full face in highly squeezing/swelling ground under 500 m cover for the high-speed railway line between Bologne and Florence, Italy (turnkey contract).

By Paolo Cavalcoli, Marco Ziller

"ABSTRACT: In the year 2010 the State of Denmark together with the Municipality of Copenhagen, launched a very important and complex Project : the complete construction of a new double Subway Line :the CITYRINGEN.Copenhagen is the capital with a metropolitan population of 1,9 million.This line is like a ring placed in the very town center which includes all the most historical and monumental buildings and churches, with a total length of 17 km, and the presence of 17 stations plus 4 service shafts.The buildings have been built in the last centuries in an area where the groundwater is near to the surface and there are lakes and channels: the techniques adopted were advanced for those times, but limited as far as regards settlements and resistance to horizontal movements.The soil consists in 2 main groups.1.Upper sediments of the glacial ages : thickness total = 5-20 m composed by clay- silt-sand-gravelcobbles- granite boulders and flint in blocs and in layers : frequency and size of these obstacles wherenot determined.2.Limestone layers : 2a. upper limestone : highly fractured ,highly permeable2b.Itermediate limestone : less fractured, medium permeability.2c. Lower limestone : almost not fractured, low permeability.2d Bryozoan limestone : composed by fossils with microscopic dimensionsIn all the limestone formations there are important layers of flint , having thickness variable up to 3 m and important extensions. Water : in a part of the areas of the Cityringen the water is drinkable and utilized in the public waternet.Pollution: there are polluted zones due to previous industrial activities. Benzene areas have been identified, and for those areas special protections against pollution have been implemented.METROSELSKABET ,the public owner of the Cityringen,has set as priority to operate for the construction of the Cityringen the full protection of the environment and the respect of all the stakeholders :Very strong limits for the exhausted gas emissions have been introduced, by far stronger than those applied from the State of Denmark, very strong limits for the acceptable noise emission. And last but not least very important safety measures and procedure to avoid any accident on site."

Jan 1, 2014

By Anthony S. Spearing

The vast majority of the estimated 100 million rock anchors installed in mines in the USA per year use resin cartridges (Tadolini and Mazzoni, 2006). About 4.5 million per annum of these are bolts with a mechanical shell that if properly installed become effective active supports on installation. In addition, cable anchors (mostly passive) are installed with typically 4 ft of effective resin anchorage length sometimes with mechanical shells, which further makes the installation more difficult. This is because the cable (even with a stiffener tube) is not very rigid. When installing bolts with mechanical shells and cable bolts in the holes, the back-pressure can be so high that the installation is unsuccessful often creating a ?spinner? (an un-tensioned bolt) at best or buckling the bolt thus requiring another bolt/cable to be installed, or leaving a poorly functioning unit. The installation problems can create a significant potential safety hazard and waste time and money. Using a purpose designed test rig that physically inserts different rock anchors into pipes with resin and measure the back-pressure developed with time during the insertion/ installation. The test installation procedure is designed to mirror that used underground by rockbolt operators in coal mines. In addition a computer model has been calibrated that can predict the approximate back pressure of new anchor and resin combinations acting as a screen before physical testing. This research has lead to an understanding and quantification of the insertion back-pressures and this already resulted in improved prototype designs that could lead to more reliable mechanical shell and resin bolt installations.

Jan 1, 2009

n the early days of the Hauraki goldfield (1866 to 1889) almost the only system of ore treatment was wet crushing followed by copper plate amalgamation. A further saving of bullion was in most cases obtained from the tailings by means of pans or berdans. Though this system was not always as efficient as might have been desired it answered fairly well for the bulk of the gold-bearing quartz of the Thames and Coromandel districts, where the gold occurs chiefly in the form of visible particles, and there is not a great deal of silver. It failed, however, with most of the ore found in the Upper Thames or Ohinemuri district, especially in the Karangahake and Waihi portions of the field. In those days the cyanide process was not, and the usual prescription of the mining " expert" was smelting. At Karangahake, many attempts were made to discover a payable method of treatment for the so-called" refractory" ore, but on thewhole with very 'little success, and the district struggled along for a number of years without adding very materially to the production of gold in New Zealand. At Waihi, the Martha Co.'s stamp battery treated by wet crushing and copper plate amalgamation some 18,000 tons from the Martha Reef, worth probablyat least £4 per ton, but the average return was considerably less than £1 per ton, a sum which barely paid working, expenses, and consequently the shareholders were glad...

Jan 1, 1903

By Fidelis T. Suorineni

Rockbursts are a major hazard in deep hard rock underground mining and tunneling. To date a significant number of rockbursts still defy conventional explanations. A review of rockburst case histories in the literature has shown that pillars and tabular excavations under shear loading are prone to rockbursting in situations where they are least expected under conventional knowledge of rockburst causes. Despite the evidence of the effects of shear loading on underground infrastructure, and the frequency of their occurrence, little is known about how this loading mechanism causes such large magnitude events and extensive damage. In this paper analytical and numerical modeling are used to understand the behaviour of pillars and tabular excavations under shear loading. The numerical modelling results show that pillars under shear loading are less confined than their equivalents in loaded in pure compression in the same geologic environment, and are therefore more brittle and weak. For tabular excavations under shear loading, the behaviour depends on whether such excavations are continuous, co-planar or offset with rock bridges. Analytical results based on slit theory show releasable potential energy in tabular excavations increases nonlinearly with excavation half-span. The study results are important for the safe and economic extraction of orebodies under shear loading.

May 1, 2011

Cessation of mining on the Bendigo goldfield makes it evident that, as the older generation fades away, knowledge of the famous Bendigo saddle reefs will be limited in the future by their written records. It is important therefore that the summarised account by D. E. Thomas (1953) in the Geology of Australian Ore Deposits should not be misleading. Fig. 6 in this article is stated to portray a cross section and longitudinal section through a series of gold shoots in the Garden Gully 300 ft. reef. The gold shoot along the capof the saddle reef is represented as extending down the east leg in a series of prongs, with the tips of the prongs about 50 ft. apart. It is the purpose of this note to indicate that this illustration can be suspected to be a diagram of the old stopes instead of a diagram of the distribution of gold in the quartz.The original sketches of Figs. 6 and 7 in Thomas' account were extracted, I believe, from the field note books of H. S. Whitelaw, years after his death in the late twenties. Whitelaw was stationed in the Bendigo office of the Geological Survey of Victoria, carrying out geological surveys of the Bendigo mines. He was there for many years before the Gold Research committee started its investigations in 1916 and he was acutely aware of the problem attached to the distribution of gold in the reefs. He had felt concern that manyauriferous reefs were being mined without adequate study and record and he decided, as he expressed it to me, to pick up what he could as he went along. There can be little doubt that the diagrams of Figs. 6 and 7 are products of this resolve.Opportunities to investigate gold occurrences at Bendigo were limited before 1916 because the field was operated by Manuscript received at The Institute 18th November, 1960.

Jan 1, 1961

By Jay C. Hanson

Various electrical and electromagnetic (EM) geophysical techniques are currently being evaluated by the U.S. Bureau of Mines for their effectiveness in the detection and monitoring of electrically conductive (1 to 5 S/m) lixiviant (leach solution) to depths of 600 m, either above or below the water table. These techniques include magnetotellurics (MT) , controlled source audiofrequency magnetotellurics (CSAMT), resistivity and focused resistivity, ground-penetrating radar (GPR), frequency-domain electromagnetics (FEM), and time-domain electromagnetics (TEM). Of these techniques, TEM may be the most effective, but CSAMT and focused resistivity also hold promise. Geophysical computer modeling of the borehole TEM technique was conducted based on an idealized geoelectric section (layered earth) with characteristics based on the Santa Cruz porphyry copper deposit near Cas a Grande, AZ. Layer resistivities and thicknesses were obtained from geophysical data and geologic logs available from the site. Modeling of borehole TEM in both preleach and during leach situations was conducted. Simulating the TEM method using computer modeling proved to be encouraging since there were substantial differences between leached and nonleached responses. The modeling does not prove the effectiveness of TEM in the field, but does indicate that detection of deep lixiviant zones is theoretically possible.

Jan 1, 1992

By Ian Gordon Hall

El presente texto describe el proceso de recuperación de las partículas ultrafinas de casiterita en los relaves de la mina San Rafael a través de diversas pruebas metalúrgicas, donde se usaron dos tipos de concentradores centrífugos, los cuales indicaron la posibilidad de una recuperación de 50%, produciendo concentrados de 50% Sn. Asímismo, se instala una planta piloto donde se verifica el proceso de las distintas configuraciones y combinación de equipos, como el efecto de las cargas circulantes. Paralelo a ello, se realizan pruebas para aumentar la ley de los concentrados primarios y así obtener concentrados finales a través de concentración gravimétrica.

Sep 12, 2005

By F. L. Pirkle

A heavy-mineral deposit about 1.6 kilometers (I mile) in length and averaging about three meters (10 feet) in thickness is exposed approximately130 kilometers (80 miles) east of Denver, along Interstate 70, in Elbert County, Colorado near the town of Limon. The deposit is exposed in a geomorphic feature known locally as Titanium Ridge. The dominant heavy minerals, accounting for about 70% of the total heavy mineral suite by weight, are ilmenite, garnet, and zircon. The mineralized zone appears in a series of visually interpretable facies that are stacked vertically and represent subtidal, forebeach, backbeach, washover fan, and aeolian depositional environments. These paleoenvironments are analogous to depositional environments represented by a modern heavy-mineral bearing facies tract on St. Catherines Island, Georgia. Thus, Titanium Ridge provides evidence that heavy-mineral accumulation models for late Cenozoic deposits in the Georgia and Florida coastal plains are applicable to heavy-mineral deposits of the Western Interior subsurface and, by implication, the Western Interior Seaway, extending from Mexico to the Canadian Arctic.

Jan 1, 2011

By Kazunori Matsushita, Masaru Sakakibara, Kenji Harada, Naotoshi Shinkawa, Mitsuo Nozu

The Sand Compaction Pile (SCP) method has been widely used as a typical countermeasure against liquefaction in Japan, and its effectiveness has been confirmed in many case histories of damages caused by the past large-scale earthquakes. A series of studies were conducted to evaluate the effectiveness of the compaction method and other factors, if any, in sustaining a seismic force that is greater than the assumed one and caused no damage. Based on the results of these studies, the Architectural Institute of Japan (AIJ) has indicated in its “Recommendations for Design of Ground Improvement for Building Foundations” published in 2006 that the liquefaction resistance ratio (tl/sz) of the composite ground, which consists of sand piles and surrounding compacted ground, is higher than the RL calculated by using the SPT N-values of the ground in-between the sand piles. In this paper, statistical analysis of safety factor against liquefaction, FL, was performed by using the SPT N-values of ground in Port Island and Rokko Island which were both fully reclaimed islands in Kobe city during the 1995 Hyogo-ken Nambu Earthquake (classified as intense shaking) and, together with the consideration of relative settlement, resulted in tl/sz of the composite ground being 1.5~2.5 times of tl/sz of the soil in-between piles after improvement. Furthermore, the liquefaction resistance curve of SCP-improved sites obtained from the relationship between SPT N-values and cyclic shear stress ratio during the 2011 off the Pacific Coast of Tohoku Earthquake, which was regarded as long-duration earthquake, was plotted to the left side of the curve originally proposed by Japan Road Association. Thus, the liquefaction resistance of the improved ground was found to be higher than that of the natural ground, even for the same SPT N-values, verifying the validity of the AIJ recommendation.

Jan 1, 2017

By Luis Martín Tejeda

El presente texto señala cómo los parámetros geotécnicos de resistencia y deformabilidad pueden generar mayor confiabilidad en un estudio técnico. En este sentido, la literatura geotécnica indica que los resultados obtenidos a través de métodos numéricos son sensibles a la variación de estos parámetros y que algunas propuestas de cálculo son más satisfactorias. Para ello, se utilizó el criterio de falla de Hoek & Brown en términos de Mohr–Coulomb, donde se presenta un ejemplo aplicativo para mineria superficial, en el cual el factor de seguridad y la probabilidad de ruptura del macizo rocoso son calculados mediante métodos geoestadísticos aplicados a la ingeniería de rocas (FOSM - First Order Second Method y puntos de estimación de Rosenblueth).

Sep 19, 2006

In referring to two subjects of interest to the Members of this Australasian Institute of Mining Engineers, I would at the outset desire to express our gratification that to-day we are able to welcome as now united with ourselves, those members who until recently constituted the New Zealand Institute. It is hoped that the amalgamation so amicably arranged may be productive of the best results to all concerned, incorporated as this combination has been at the moment of the fulfilment of that greater political union, the Australian Commonwealth.Since last Annual Meeting held in Brisbane, we have come under the same roof as the Chamber of Mines of Victoria, and we entertain the hope that as that Chamber and this Institute possess so many interests in common in the encouragement and advancement of mining and metallurgical progress in these colonies, that much mutual benefit will ensue. There are many directions in which each body can assist the other, and I trust that a friendly co-operation will be maintained.It is gratifying to feel that in all the colonies a distinct movement is being made to increase the facilities for education in Mining and Metallurgy but if I may refer to our colony of Victoria in particular, we have to express the profound regret that in the means of education in the higher branches, we occupy an inferior position, and it is quite certain that we will continue to do so unless the Government is prepared to subordinate provincial considerations to the weightier.

Jan 1, 1901

By A. S. Usmani

The flow associated with the pouring of molten metal into moulds has been modelled on the basis of certain simplifying assumptions. A finite element based Navier-Stokes equation solver has been used to analyse the flow. The velocities obtained from the Navier-Stokes equation solver are used to advect a pseudo-concentration function for modelling the fluid front. A simple problem with a known analytical solution is solved first to test the model. Subsequently, several more examples with varied geometrical configurations are modelled, including one with curved flow boundaries.

Jan 1, 1992

By Pfeifer H. C, Nicacio P. A D

Sinter has been used as part of the metallic charge in large-scale blast furnaces for many years with the well-known benefits in terms of productivity and fuel consumption. However, because of the high investment in a conventional sinter plant, small blast furnaces and the associated integrated mini steel plants have not taken the advantages of using sinter. Recently KTS Korf Tecnologia Siderurgica, a division of Mannesmann Demag Ltda in Brazil, has developed a mini sinter plant for which the investment is compatible with small blast furnaces. Consequently, it is of great interest to evaluate the economical impact of using sinter in such small-scale integrated steel plants. In order to compare two alternatives, ie 100 per cent ore and 70 per cent sinter in the blast furnace burden, mass and heat balances for the entire operation from sinter plant through the blast furnace and EOF-based melting shop, were performed to evaluate the final production cost of the liquid steel. It was found that, depending on the sinter feed price, substantial savings can be obtained with the use of sinter.

Jan 1, 1999