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By Kyle Selga, Christopher J. Greet

"The Pulp Chemistry Monitor (PCM) has been installed and operated in a number of concentrators in Australasia, and has produced some very interesting results. PCM measures the pH, Eh, dissolved oxygen, temperature and oxygen demand of process streams within a concentrator continuously and in real time.In the example presented in the paper the cleaner feed pulp chemistry is measured, and related back to changes in the mineralogy as well as variations in metallurgical response. For example, a decrease in Eh and dissolved oxygen as well as an increase in the oxygen demand. These changes in the pulp chemistry appear to coincide with increases in the feed grades, probably higher pyrite grades. Further, these variations in pulp chemistry and feed mineralogy have a negative impact on the concentrate grade and recovery.The implication is that if the pulp chemistry is monitored it is possible to predict changes in the mineralogy of the system, and from this the metallurgical response. Further, the changes in pulp chemistry can be used in a control system to counter the changes in mineralogy and maintain the metallurgy.IntroductionIt has long been recognized at a fundamental level that the flotation behaviour of sulphide minerals is dependent on the pH and Eh of the system (for example: Tolun and Kitchener, 1964; Woods, 1976). However, measuring pulp chemical parameters within an operating concentrator has had limited attention. Woodcock and Jones (1970a and b) were among the first to actually collect data from operating plants. Jones and Woodcock (1984) identified some of the chemical complexities of flotation pulps, and noted that most concentrators already operate at high levels of metallurgical performance but there was still considerable scope for improvement. These gains would, in part come from more effective chemical control. In the same volume, Healy (1984) discussed metal ion hydrolysis and precipitation, redox chemistry and how the surface chemistry of sulphide minerals can be influence flotation behaviour. The impact of grinding environment on the pulp chemistry and flotation response of a complex polymetallic sulphide ore is discussed by Forssberg and Subrahmanyam (1993). Their work essentially contrasts the pulp chemical and flotation performance of pulps ground with conventional ferrous grinding media to a fully autogenous system. The data suggested that the reduction or removal of iron hydrolysis contamination from the system could have a positive influence on flotation behaviour, and perhaps the first stage of “controlling” the chemistry of the system should be in the grinding circuit. Grano et al (1995) demonstrated that the collection of pulp, solution and surface chemical data could identify weaknesses within a concentrator, and from these data develop, test and implement solutions that improved the process. Greet et al (2006) showed that the pulp chemical trends observed through primary grinding and rougher flotation circuits of most sulphide flotation concentrators are approximately the same. There are differences in the magnitude of various pulp chemical parameters (pH, Eh, dissolved oxygen, temperature and oxygen demand) as a result of variations in the feed mineralogy and processes employed. Further, it was noted the Eh shifted to more reducing values of the ten days measurements were collected, and this change could be traced to an increase in the iron sulphide content of the feed. Metallurgically, this resulted in an increase in nickel recovery through the recovery of nickeliferous iron sulphides, and a decrease in nickel concentrate grade."

Jan 1, 2016

By Donald W. Mitchell

Research shows that water neutralizes the explosion hazard of coal dust when present in sufficient quantity and when intimately mixed with the dust. The quantity of water required to neutralize coal dust and coal-rock dust mixtures is about equal to the limiting moisture adsorptive capacity of the dust; the adsorptive capacity increases with increase in the fineness and volatile content of the coal. Pools of water or high atmospheric humidity do not reduce the explosion hazard. Although wetted dust is less dispersible than dry dust, poor dispersibility cannot be relied on as the sole safeguard against explosion. Dust mixtures that contain water in excess of their limiting adsorptive capacity are dispersed and ignited by severe initiation sources. Pure coal dust adsorbs water with difficulty and retains water poorly; adsorption and retention is increased by the addition of rock dust the coal; the rock dust agglutinates wetted coal and assures that incombustible is present should drying occur. Therefore, it is advantageous to rock-dust wet areas in bituminous coal and lignite mines. When coal-rock dust mixtures are wetted and subsequently dried, the explosion hazard is about the same as for dust which was not wetted.

Jan 1, 1962

By S Vianna, K Caldwell, R Silva, T Olson, D Bell

Studies to enhance the FLSmidth forced air machine through changes in the design, showed important improvements through changes in the number of Rotor blades, stator designs, rotor air distribution and other designs features. The main outcomes from this study highlighted that increasing the number of rotor blades increased the selectivity while decreasing power requirements while stators with slots have better results in terms of recovery, flotation efficiency and selectivity than without slots.Also the rotor air distribution makes a difference in the design when comparing different distribution criteria whilst keeping all features of shape and number of blades etc constant. At the most efficient rotor air distribution design, copper recovery reached one of the highest values while keeping good selectivity. The possible explanation for that is the increase in the pump capacity indicated by the increase in the specific power.It was seen as significant that reduction in specific power for some designs tested compared with the then current standard design had an average of 30% less power consumption.As a result, FLSmidth was able to identify new designs that decreased power and improved recovery, as well as, identifying some designs that specifically improved fine and/or coarse particle recovery.CITATION:Silva, R, Caldwell, K, Bell, D, Olson, T and Vianna, S, 2013. FLSmidth flotation developments - Dorr Oliver machines, in Proceedings MetPlant 2013 , pp 413-430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By N Strong

Cracow is a high-grade; low-tonnage underground gold mine located approximately 500 km north-west of Brisbane in Central Queensland. It is a steeply dipping, narrow vein, epithermal gold and silver deposit that is accessed via a decline from surface. Cracow is owned by joint venture between Newcrest Mining (70 per cent) and Sedimentary Holdings (30 per cent). The orebodies are 5 m wide on average and the ore is extracted via sublevel open bench stoping. Stopes are extracted to a strike of approximately 25 m before being backfilled with waste. Prior to the introduction of electronics, the mine would remove a small amount of the previous backfill out to create a void, and then begin blasting two to three rings at a time, with the ore being extracted between each blast. This method caused the ore to be blasted onto the waste backfill resulting in dilution of the high-grade ore. It also meant that the extraction of each stope took a number of weeks and numerous blasting events. In the fourth quarter of 2005, the mine struck a geotechnically sensitive stope, where all 20 rings had to be extracted in a single shot or risk possible geotechnical problems that could sterilise the ore. Due to the limitations of NONEL« delay detonators the mine could not fire all the rings in a single shot and needed to use an electronic detonator system to extract the stope. Some unexpected benefits to the mine were increased fragmentation, reduced vibrations, reduced dilution, improved efficiency and improved hanging wall and footwall conditions. After the success of this first electronic shot, the mine has since moved to firing all their stopes with electronic detonators. With electronics the mine has been able to fire much larger blasts, and has in fact moved to firing their blasts in the opposite direction, firing towards the draw point instead of into the waste backfill, thus reducing ore dilution.

Jan 1, 2007

By Ola Lindahl, Mark Irving, John Hutchings

"Blasting is a process starting with a geometric description of the block of rock and ending with a pileof fragmented material. A key step in improving the productivity and quality control over the processis the integration of blast planning software, explosive delivery control systems, and blast recordingwithin one seamless customer solution."

Jan 1, 1997

By Rüdiger Wunsch

The new high speed Vienna - St.Pölten line and the Lainzer tunnel are to be connected to the existing Western railway line in Vienna. This involves building an underground cut and cover branching tunnel which will be connected to the Western railway line by ramps. A key structure is the Herzmansky Street tunnel, which has a length of some 820m. It is to be constructed as a cut and cover tunnel using the top down method. The walls of the tunnel are designed as a water resistant structure consisting of double walls, an outer wall of bored piles and an inner reinforced concrete wall. The bored pile wall will be used as a temporary retaining wall during the construction phase and will also be a structural part of the per­manent tunnel wall. The retaining walls of the open pit, which will have a depth of up to 14m and a width of 12m, were investigated as a non-contiguous bored pile wall and overlapped bored pile wall. Preventing ground water from penetrating into the pit is of paramount importance. The high ground wa­ter level is the determining factor for the dimensioning of the bored pile wall and results in the require­ment for a water resistant concrete structure. It has been necessary to adopt adequate measures, therefore, in order to reduce the hydrostatic water pressure during the construction phase, assuming economical pile dimensions.

Jan 1, 2000

By T. C. Eisele

The use of column flotation was considered for the ?reverse flotation? of iron ore, where the gangue (quartz) was recovered in the froth product. This use of the froth for carrying the gangue mineral rather than carrying the valuable concentrate significantly changes the operational requirements of the column. The objective of this work was to determine which of several column flotation technologies would be most suitable for this type of flotation operation. Studies were carried out using both the Jameson column and the Deister column. Comparative results are presented that show the capabilities of both column types in this application relative to conventional Wemco flotation cells. Columns were demonstrated to have grade-recovery performance superior to what could be achieved with conventional cells. Two-stage flotation with the columns could produce a concentrate that was up to 70.2% Fe at 87.5% iron recovery, compared to 70.4% Fe at only 77.7% iron recovery for four stages of flotation in conventional cells. It was shown to be particularly important to operate the columns to recover a maximum of the quartz gangue into the froth. It was noted that there are often problems in scale-up of laboratory columns to plant scale, because the increase in height and the decrease in the ratio of height to diameter at the larger scale allows more axial mixing and bubble coalescence, both of which degrade the column performance. Horizontal baffling was shown to improve column performance by reducing axial mixing and breaking up large bubbles, and so the use of such baffles in the reverse flotation application was investigated.

Jan 1, 2007

By Richard F. Link

A statistical technique, useful to analyze assay and other data characterized by location in three dimensions, is described in this Bureau of Mines report. If present, trends in the data are defined for the purposes of improving ore estimation, predicting ore beyond existing workings, and aiding geological interpretation. The technique is to fit linear and quadratic polynomial equations to the data through the statistical method of regression analysis. The fitted linear equations have the geometric form of hyperplanes; the fitted quadratic equations have the geometric form of ellipsoids or elliptic hyperboloids of one or two sheets. To visualize these three-dimensional forms, contour maps of a series of plane sections through the fitted surfaces are plotted. Both the fitting of the polynomial equations and the plotting of the con-tour maps are done by electronic computer to facilitate calculations and to obtain accurate results. Computer programs are described in appendixes. Methods employed are illustrated by an example analysis) based on data from a part of the Fresnillo mine) Zacatecas, Mexico.

Jan 1, 1966

By None None

Use this month wisely — go online and take advantage of your new member benefit. As an SME member, you can read and download for free all of the full-text papers of the Mining, Metallurgy & Exploration (MME) journal, including the 22 papers in the launch Special Issue on Mineral and Metallurgical Processing in Honor of Professor Emeritus Douglas W. Fuerstenau as well as the archived articles of Minerals & Metallurgical Processing (MMP), all the way back to Vol. 1, No. 1. Just follow the instructions on this page.

By Jr. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Jan 1, 2012

Visit to the Datsun Nissan Company's body pressing and assembly plant at Rosslyn, Pretoria, and the Claremont-Danville Tunnel on 27th February, 1970. The excursion arranged for the 27th February to the Datsun Nissan motor car assembly plant at Rosslyn, near Pretoria, in the morning and the Claremont-Danville tunnel in the afternoon was well supported by some 43 members. The visitors were met at the factory by Mr Rademeyer, the Industrial Relations Manager, and members of his staff and were taken to the artisan training centre for light refreshments. There is a well-equipped training section with an air-conditioned lecture hall; we were told that such training facilities were important because of the cosmopolitan nature of the artisan staff. The visitors were divided into small parties and taken to the tool die and jig-making section, which is perhaps the key department for a factory of this nature. There the many dies for the presses in the body pressing section, as well as the complicated jigs for body welding are made. The technique for making the castings for the dies is interesting. A polystyrene model of the casting is embedded in moulding sand. In a neighbouring foundry molten metal is pressed into the headers and burns away the polystyrene, which leaves no residue, and this exactly fills the space occupied by the model. This rough casting is then machined in large copying machines (costing as much as Rl80 000). An exact plastic model of the surface of the pressing required, set up in juxtaposition to this casting is traversed by a master stylus which operates the slave milling cutter, thereby machining the surface to close tolerances. The machined casting is cleaned up by hand and finally finished in large spotting machines, using a blue dye to show up high spots, to the fine degree of accuracy required. The body pressing section was next visited. There the large number of pressed parts which make up a vehicle body are pressed out of special deep drawing steel plate. Some of the largest presses were capable of applying a pressure of 1 200 tons and cost as much as Rl85 000 each. The visitors then followed through to the assembly section where jigs are used to hold together the many pressings, which are then spot welded into body frames. The frames go to an assembly line where they are finished to the stage for painting. The continuous crawl painting assembly line carries the frames through all the stages of prime coating with zinc phosphate sprayed on in a tunnel, followed by immersion of the lower parts in a priming bath, then drying and spray painting and baking in tunnels. The body frames, after painting, join another assembly line, where the doors, upholstery and many fittings are attached. After this stage the completed bodies are lowered onto and attached to the chassis units which are largely assembled from imported parts (engines, transmission units, etc.). From the end of the line the completed cars are driven off to the trial track and then pass through a tunnel with powerful water sprays to detect leaks in the body work. The proportion of locally made parts is just on 45 per cent. An interesting aspect of the assembly organization is that, of the 140 or 160 cars completed each day there may be included some of each of the Datsun model as well as some Renault and Alfa Romeo models models which are assembled by this company. The change from one model to another several times a day does not present any difficulty to the organization. Each section of the assembly plant 'buys' the units from the preceeding section and 'sells' to the succeeding section. This means that the responsibility of each section ends when the unit is sold to the next section. The cost of repairing any faults found subsequently is charged to the section where it is found, which puts a powerful emphasis on meticulous inspections between sections to safeguard their costs. After the tour the parties assembled at the lecture hall where a lavish cold buffet luncheon was provided by the company. After luncheon Mr A. R. C. Fowler, on behalf of the Institute, thanked the Managing Director, Mr W. J. Wilson and his staff for this most interesting and well organized visit. The party then left for the Claremont-Danville tunnel. The tunnel is being driven by General Mining Federale Kontrakteurs through the Daspoort Range, Pretoria, to link the suburbs of Danville, near Iscor, and Claremont, which at present can only be reached by a nine mile detour. It is estimated that some 6000 vehicles per day will use the tunnel. Before entering the tunnel a short talk was given by Mr Ross who is in charge of operations. He called on various officials and staff of the Consulting Engineering firm, Basil Read (Pty.) Ltd., to describe the tunnel and

By K. Zenger, J. Kaartinen, J. Huuskonen, S. Torttila, S. Lähteenmäki, J. Pietilä

"Pyhäsalmi Mine in Finland has a long history of continuous process development. The concentrator processes Cu-Zn-sulphide ore with high recoveries. An on-line flotation simulator has been developed to maintain and further improve the flotation performance. Consisting of a flotation kinetic dynamic model, and interconnected with process control software, the simulator can be used for training new control room operators in various scenarios. For daily operation, the model parameters are continuously adapted to take into account the changing process conditions. On-line simulator tracking the process can provide the process operator new information in several ways: a) values of unmeasured process variables are obtained by displaying the corresponding simulator values, b) predictions of future process states and outputs are calculated and displayed, c) information of changing process parameters can be used as an indicator of e.g. change in the processed ore type. This paper describes the adaptive simulation system and its usage at the Pyhäsalmi concentrator.IntroductionPyhäsalmi massive sulphide orebody is located in central Finland. Operation of the mine started in 1962 and it is currently producing copper (Cu), zinc (Zn) and sulphur (S) concentrates. The concentrator control and optimization system has a long history of successful continuous development during the past decades (see e.g. Huuskonen & Moilanen, 2010). An on-stream analyzer has been a part of the automatic process control since 1968 (Lähteenmäki, Miettunen & Saloheimo, 1999). First control algorithms based on a flotation mathematical model were developed in 1971 (Koivistoinen & Miettunen, 1985). In 1990’s the development of a froth machine vision systems started (Kaartinen, 2009; Kaartinen, Roine & Hätönen, 2009). More recently Pyhäsalmi Mine Oy has been involved with several national development projects dealing with particle size distribution measurements (Kaartinen & Tolonen, 2008), spectral analysis of flotation slurries (Haavisto, Kaartinen & Hyötyniemi, 2008), and dynamic simulation of flotation processes. The latter topic is further elaborated in this paper."

Jan 1, 2015

By Oswaldo Ortiz Sánchez

El presente trabajo describe la alternativa de uso del mortero de resina en la fijación de pernos de anclaje de las excavaciones mineras, consolidación y disipación de vibraciones en los cimientos de plataformas para la instalación de molinos, winches, tolvas, etc. Esta opción surge en respuesta al problema de reforzamiento con pernos de anclaje en ambientes con aguas corrosivas o en proceso de deformación acelerada en las excavaciones mineras, así como ante obstáculos de subsidencia de cimentación en plataformas, donde se encuentran instalados equipos de gran tonelaje, y que producen fuertes vibraciones durante su funcionamiento.

Jul 31, 2003

By E. F. Johnson, V. O. Naumann, D. P. Bossler

A method is presented for calculating individual gas and oil or water and oil relative permeabilities from data obtained during a gas drive or a waterflood experiment performed on a linear porous body. The method has been tested and found both rapid and reliable for normal-sized core samples. INTRODUCTION Individual oil and gas or oil and water relative permeabilities are required for a number of reservoir engineering applications. Chief among these is the evaluation of oil displacement under conditions where gravitational effects are significant, such as a water drive or crestal gas injection in a steeply dipping oil reservoir. Numerous proposed methods of obtaining relative permeability data on reservoir core samples have been too tedious and time consuming for practical use, or have yielded questionable and sometimes inconsistent results. A method has been developed by which the individual relative permeability curves can be calculated from data collected during a displacement test. The method is based on sound theoretical considerations. Using this method, with a properly designed experimental procedure, relative permeability curves can be obtained using core samples of normal size (i.e., 2 to 3 in. in length and 1 to 2 in. in diameter) within a few days after receipt of the core. In a recent publication D. A. Efros1 describes an approach to the calculation of individual relative permeabilities that is based on the same theoretical considerations. We believe the approach described in the present paper is more adaptable to practical application than the method implied by Efros. In addition, comparisons with independently determined relative permeabilities are furnished to substantiate the reliability of the new method. DERIVATION Previously the theory of Buckley and Leverett as extended by Welge2 as been used to calculate the ratio of relative permeabilities. In the derivation which follows, this theory is further extended to permit calculation of the individual relative permeabilities. The theory assumes two conditions which must be achieved before the method is applicable. They are that the flow velocity be high enough to achieve what has been termed stabilized displacement,3 and that the flow velocity is constant at all cross sections of the linear porous body. In stabilized displacement the flowing pressure gradient is high compared with the capillary pressure difference between the flowing phases. The high pressure drop insures that the portion of the core in which capillary effects predominate will be compressed to a negligibly small fraction of the total pore space. The assumption of constant flow velocity at all

By Shosei Serata

The Stress Control Method improves productivity and safety in underground coal mining. The method stabilizes the roofs and floors of mine openings in both shallow and deep coal beds, regardless of whether or not there are ground stability problems. This paper describes the means by which a tapered pillar experiment is used to collect in situ data, which is then used as input for a computer model. The resulting computer model is then used to optimize Stress Control design for the mine under study. The behavior of any underground coal mine is not elastic, as is generally conceived in the conventional view of rock mechanics, but rather is highly time-dependent and site-specific. Unfortunately, conventional rock mechanics methods based on the elastic principle are not able to capture the highly non-elastic nature of ground behavior which actually occurs. To capture actual behavior, a new method of study is required. In this regard, geomechanical study of an underground coal mine may be compared to studying the behavior of a living fish. Its true behavior zannot be understood by examining it "dead in the laboratory. It Is the "live" nature of the coal mine that is required for design optimization of the Stress Control Method in the given mine. The Stress Control Method is based on a time-dependent theory of the global behavior of the mine ground, which generally contradicts the conventional elastic theory of ground behavior. Therefore, site-specific adaptation of the Stress Control Method required a comprehensive understanding of the global behavior of the mine as a function of time and site-specific ground conditions.

Jan 1, 1986

By Dan Payne

The Crinum mine has recently completed workings in the southern area of the mine. Over the 10 years of longwall production 40 million tonnes have been extracted and the mine has experienced over 40 longwall face, 3 main gateend, and 2 tail gateend roof falls as well as 5 roadway roof falls away from the longwall. Weak roof (less than 10MPa (1450psi) in the bolted horizon) has been the principal roof control issue at the mine. However, weak, highly cleated coal, water inflow from overlying aquifers, some minor structure and a diatreme in the main headings have also contributed to the challenges at the mine. This paper describes the geotechnical experience over the 10 years, the mine?s approach to addressing the issues and the relative success of these approaches.

Jan 1, 2008

By Napisporn Memongkol

Syntheses of Al-TiC-Al2O3 and Al-SiC-Al2O3 composites were obtained in situ by carbothermal reduction of mixtures of Al powder, TiO2 powder and activated carbon powders and Al powder, SiO2 powder and activated carbon powders. The reductions were carried out in a horizontal tube furnace under flow of inert gas. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The synthesized products were mixtures of aluminum reinforce with titanium carbide and alumina and aluminum reinforce with silicon carbide and alumina. The effect of the reaction temperature (1000 o C ? 1200 o C) and condition of precursors on the Al powder, TiO2 powder and activated carbon powders and Al powder, SiO2 powder and activated carbon powders were investigated using XRD and SEM method. The synthesized products showed those composites with aluminum matrix and titanium carbide and alumina as reinforced phases and aluminum matrix and silicon carbide and alumina as a reinforced phase was formed.

Jan 1, 2006

By C MacDonald

There are many technologies available today in terms of fire and life safety in road tunnels. So many in fact that it is becoming more and more difficult for clients and contractors alike to determine what they want and what they need. From a clientÆs perspective, fire and life safety is about protection to its infrastructure and to the public at large. Conversely, the contractor is looking to meet its æfit for purposeÆ or ædeem to complyÆ requirements in the most economic and practicable way. Practices regarding fire and life safety in road tunnels have undergone a degree of transformation during the last decade or more throughout the world. This transformation has largely been driven by a series of catastrophic accidents such as the major fires in Europe including the Mont Blanc Tunnel, Tauern Tunnel, Saint-Gothard Tunnel, and now most recently in the CityLink Tunnels in Melbourne. International guidelines produced by organisations such as the Permanent International Association of Road Congresses (PIARC), the European Union, the International Tunnelling Association (ITA) and the US National Fire Protection Authority (NFPA) now provide clients, owners and designers with the tools required to define and specify the required fire and life safety systems in road tunnels. The majority of these tools are based on risk assessment and risk management. Recent road tunnel projects within Australia, however, have not referred solely to such guidelines. Clients have opted to prescribe different or additional fire and life safety requirements within the projectÆs technical specification documentation (project requirements), leaving designers and contractors with little room to implement alternatives or substitutions. Further, these project requirements are largely dictated by practice established on previous road tunnel projects within Australia. This paper looks at the current international guidelines and practices and undertakes a comparison with the EastLink tunnels in Melbourne and other road tunnels within Australia and makes assessment on whether Australian methods are the most appropriate for clients and contractors alike. Focus is directed to the key elements of fire and life safety such as:traffic envelope, barrier arrangements and emergency walkway provisions;deluge systems;drainage systems;fire rating requirements;tunnel ventilation systems;cross passage provisions;fire safety assessment;critical intelligence systems including help phones, CCTV, incident detection, tunnel signage, etc; andexternal tunnel control systems.

Jan 1, 2008

By Sydney H., Ball

ONE of the important mineral discoveries of the eighteenth century was , that of the Minas Geraes, Brazil; diamond fields. The production of this and of .other diamond discoveries in neighboring states made Brazil the premier producer of diamonds, succeeding India; its 140 years of supremacy finally passed to- South Africa- 60 years ago. Three times have diamonds contributed heavily to Portugal's somewhat checkered financial history; first in the sixteenth and seventeenth- centuries when the diamond trade of India was controlled by its citizens residing in ,Goa, later in the late eighteenth and the first 75 years of the nineteenth century when the Brazilian fields were the world's source of diamonds, and now, when the Angola diamond mines are the principal source of revenue of its colony, Portuguese West Africa. Certain phases in the history of the administration of the Brazilian field are sufficiently curious to warrant description.

Jan 1, 1929

By R. G. Fleck, W. R. Webb

Iron ore mining in the Adirondack region of northern New York dates back to the Revolutionary War. It is recorded that Benedict Arnold in his campaigns in the Lake Champlain area during the American Revolution utilized the local ores to produce armament and cannon balls. Through the efforts of early pioneers, the iron mining industry in northern New York gained impetus so that in the 1880's mines in the area accounted for nearly one fourth of the iron ore produced in the United States. Both magnetite and red hematite ores were mined during this period. With the discovery of the Lake Superior ores, the iron ore industry in New York started to decline and remained relatively unimportant until 1938. Modern day methods of mining and beneficiating sufficiently high tonnages of low-grade ores to justify the large expenditures for plant and equipment prompted a resurgence in northern New York mining. During the past several years, the production of iron ore from the Adirondack magnetites has greatly increased, and production which amounted to .6%, of the United States total during the 1918-1928 period (Mining and Metallurgy, November 1943) has been increased to 2.85% of the total in 1948. Today, Republic Steel is mining in the Port Henry-Mineville and Lyon Mountain areas; the

Jan 4, 1950