Search Documents

By Dan Witkowsky

In an increasingly environmentally conscious world, mining's importance to society has often been misunderstood and even maligned by the public. Extreme and impractical ideas have often been presented to children because of the lack of accurate, timely resource materials available to educators. In the late 1960s. two mining engineers, S.P. "Pi" Warren and C.L. "Lindy" Barker, became aware of this situation. They proposed to develop a summer field course to provide a factual overview of the minerals industry for teachers. The pair believed that teachers could become better informed to educate students, and future generations, about mining. These two Colorado Mining Association (CMA) members felt that such a course could reduce much of the misunderstanding about this vital industry. This could be done by providing a balanced perspective of mining, not only for kindergarten-through-grade-12 teachers, but also for the students they would be teaching during their careers. Students who better understood the minerals industry could better formulate an unbiased view of it. The course would seek recognized authorities from industry, academia and government who would lecture in their respective fields of expertise. The course would provide a total concept of the coal, aggregate, metals and industrial minerals industries. It would include geology, geophysics, exploration, mining, processing, marketing, product applications, economic, mining history, careers, and environmental responsiblity. When possible, site visits would permit educators to view operations and to meet the men and women who are industry leaders. Teachers would pay a small tuition fee. The balance of the program expenses for each teacher would be paid through scholarships provided by industry and individuals. The "total concept" idea obtained the support of the minerals industry. The support of CMA's Education Committee and the Colorado School of Mines (CSM) was obtained in 1968. Colorado's Commission on Higher Education approved teacher recertification credits through CSM's Office of Special Progams and Continuing Education for those successfully completing the program. The first six-week series of classes presenting the total concept of the indus¬try was held at CSM in 1969. In 1977, the CMA Education Foundation Inc. (CMAEF) was established as a Colorado nonprofit corporation. The "Total Concept of the Mining Industry" (Total Concept) course was placed under its sponsorship. CMAEF is dedicated toward this continuing education program (Table 1). In 1994, the course was streamlined to four-weeks for six hours recertification credit.

Jan 1, 1997

By L. G. Tejada, T. Sjursen

In the production of ferronickel at Falconbridge Dominicana's plant in the Dominican Republic the Reduction Plant plays a vital role by partially reducing the nickeliferous oxide ore, and pre- heating the charge to the electric furnaces. Ore is agglomerated in the form of pillow-shaped briquettes which are screened and fed to 12 open-top shaft furnaces. Hot (over 1250°C) reducing gases are partially cooled (less than 1150°C) and introduced through a set of primary tuyeres. The reducing gas rises counter-currently to the flow of solids. A portion of the partially spent reducing gas is withdrawn at the furnace top and recirculated through a set of secondary tuyeres, 1800 nrm above the primary tuyeres. Together with the recycle gas a controlled amount of air is also added to react with the partially spent reducing gas in order to preheat and dry the charge in the upper part of the shaft furnaces. The calcine is discharged through three discharge legs and pusher block assemblies into open-top refractory lined cars. These cars are then hauled to the electric furnace, parked over selected feed ports, and discharged through bottom gates. The furnace exhaust gas is de-dusted in cyclones and then passed through Venturi scrubbers. The slurry is fed to a thickener, filtered, and recycled to the ore receiving hopper in the ore preparation area. Dust generated throughout the plant is collected, wetted to conform with briquette press feed, and recirculated in a controlled manner through the feed system.

Jan 1, 1979

By Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep sandstone in the Elk Basin field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes of gas in solution, saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep reservoir of the Elk Basin field has unusually varying physical characteristics, such as a saturation pressure of 1,250 pounds per square inch absolute and 490 cubic feet of gas in solution in a barrel of oil at the crest of the structure, and a saturation pressure of 530 pounds per square inch absolute and 134 cubic feet of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the 6a r; in solution in the oil varies from 18 percent for oil on the crest to 5 percent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of oil in the structure. Many geologists and petroleum engineers have considered all the oil in a petroleum reservoir to have uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas. That such is not always so is borne out by the results of the study made by the writers.

Jan 1, 1951

By R. Gatewood

The solution here offered is at once simple and important in its direct and indirect bearings. According to the principles of surface-tension, which will be found sufficiently enlarged upon for present purposes in Clerk Maxwell's excellent little treatise on The Theory of Heat, a mechanical mixture of liquids will frequently of itself divide into groups, consisting of liquids mixing among themselves but withdrawing from the other liquids. The following simple and familiar illustration will suffice: " If we mix water with alcohol, the liquids diffuse into each other. If we now attempt to mix oil with the alcohol and water, the two liquids separate from each other of themselves, and in the act of separation sufficient force is brought into play to set in motion considerable masses of the fluids." Maxwell goes on to show that this relative energy is one of arrangement, depending on the nature of the fluids and the area of the surface of contact, the act of separation tending to reduce this surface to a minimum consistent with equilibrium; that this surface-tension exists between a solid and touching fluid, either liquid or gaseous, being of one sign or the other, in the case of a liquid, according as it tends to draw itself up into a drop on its surface or to spread and wet the solid. After considering various cases, lie states that which particularly interests us, thus : " When a solid body is in contact with two fluids, then, if the

Jan 1, 1885

By Hans Neuberger

INTRODUCTION IN our everyday life, visual perception plays perhaps a more important role than any of the other senses with which we are equipped by nature. It is, therefore, quite understandable that the average person associates 'with the term "atmospheric pollution," clouds of dust, palls of smoke or deposits of soot, phenomena which are so familiar to the residents of industrial cities. On the other hand, "air" is usually considered the prototype of the invisible, of the intangible, and any suspensions in the air which do not conform to this concept, are regarded as foreign to the atmosphere and thus as "pollution." According to Webster, the term "pollution" implies uncleanness, impurity, in short, something undesirable. Although the scientist often accepts popular concepts, he is generally inclined to suspect that apparently "obvious" phenomena imply, literally, "more than meets the eye." To show that this suspicion is also justified with regard to atmospheric pollution, is the objective of this discussion. It will be shown that what seems foreign to the air at first sight, is by nature an integral part of it, and that the more important aspects of pollution generally escape attention. THE ATMOSPHERIC CONSTITUENTS We can distinguish two classes of atmospheric constituents: the permanent gases, chiefly nitrogen, oxygen, traces of argon, neon, and others, and the variable constituents which include water in its different states, carbon dioxide, ozone, and various suspensions, either in gaseous, liquid or solid form. These suspensions, known by the collective term "Aerosol,"20 will be considered in detail. DUST There are two general types of aerosols: the first type is represented by the socalled "neutral" particle 3, commonly known as dust and experienced by everyone, as it is the more conspicuous type of suspensions. . It often represents a special problem to the mining engineer, the mechanical engineer, the industrial engineer, and many other professional men. Dust consists of finely divided solids derived from weathering, drilling, handling and preparation of rocks and coal. Dust may also consist of organic or inorganic particles resulting from manufacture of a variety of products such as flour, rubber, lime and steel, from traffic on land be it on the highways, on rails or in city streets, from decomposed vegetation or from volcanic eruptions. Perhaps the most reviled member of this class of suspensions is the soot and fly ashes from coal fires and other combustion processes. The cosmic source of dust, namely the injection of meteoric matter into the atmosphere, is of minor significance because the concentration of particles is exceedingly small despite the relatively large mass of material invades the earth’s atmosphere from space

Jan 1, 1948

By D. Elroi

This paper addresses the sharing of 2D and 3D data between GIS and mine planning software. Two-dimensional (2D) data, and now three-dimensional (3D) data as well, can be formatted such that both types of software can use, exchange, and display the same datasets. This increases the ability to share data between such groups as environmental, exploration, and mine planning. It overcomes shortcomings of mine planning software in areas of open database connectivity, spatial analysis, and data input and output. It also helps to overcome shortcomings of GIS software in the areas of geologic modeling, three-dimensional interpolation, and visualization.

Jan 1, 1998

By Giovanni A. Bonita

The new Embassy of the Peoples Republic of China in the United States (Chinese Embassy) is located in the Embassy Row portion of Northwest Washington DC. The 475,000 ft2 (44,125 m2) structure has five levels below ground and four above, making it the largest embassy in Washington DC. The structure approaches the property line on all sides, and is immediately adjacent to several foreign embassies and a secure U.S. Federal Building. A vertical soil nail wall was used as the primary support of excavation (SOE) system for the project. The soil nail wall was irregularly shaped, benched in areas, and reached total heights up to 98 feet (29.9 m). The soil nail and shotcrete system consisted of approximately 1,600 soil nails and 50,000 square feet (4,645 m2) of exposed shotcrete wall surface. Tight excavation requirements were defined for the project due to the location of the building relative to the property line, requiring fairly precise wall positions and shotcrete tolerances. Design challenges included soft soil conditions, inside wall corners, underground utilities, and seismic impacts from blasting. The paper will focus on the design, construction, and performance of the soil nail SOE system, as well as touch on the logistical and political factors that influenced the design. The paper also notes the Value Engineering and communication approaches that were generated during construction. These efforts resulted in a significant improvement in the quality control and quality assurance exhibited on site, expedited the schedule, and led to significant cost savings to the contractors, engineer, and owner.

Jan 1, 2006

By Kessi E. Zicko, Eric A. Hackenberg, Paul J. Lewis

"Following snow melt and spring rains in 2011, a landslide measuring approximately 600 feet long and 300 feet in slope length occurred within the southbound roadway embankment of a heavily travelled 2-lane divided highway in North Central Pennsylvania. Driven steel piles were designed to stabilize the embankment slope. Factors affecting the selected stabilization technique included an adjacent reservoir, wetlands, the length and depth of the failure plane, extent of glacial lake deposits, excess pore pressures in the foundation soils, and an area of archaeological interest. Field reconnaissance and subsurface explorations including borings, instrumentation, geophysics, and laboratory testing indicated that glacial lake deposits were present in the toe region of the embankment. Instrumentation proved key in measuring excess pore pressures and in locating the failure plane, and geophysics was utilized to estimate the extent of the soft glacial lake deposits and to estimate pile lengths. The existing condition of the embankment was modeled in computer slope stability analyses, which were also used to help assign soil parameters. Significant costs were associated with constructing a berm due to the impacts on adjacent site features. Therefore, multiple rows of driven steel H-piles were designed for installation along the toe of the embankment. The design lateral load in the piles was based on slope stability analyses, and the pile size and number of piles were based on lateral pile computations with modified p-y curves to account for installing piles in an active landslide. The relationship between the factors of safety from slope stability and the LRFD pile design was significant in determining pile loads for lateral analyses.INTRODUCTIONA landslide developed along the lower portion of the southbound embankment of State Route 15 in Tioga County, Pennsylvania. The road passes through a steep valley and is located along the southern extent of the Tioga Reservoir. Although no damage to S.R. 15 was attributed to this landslide, the close proximity of the slide to the road posed a concern for the long-term stability of this section of roadway.This paper presents a summary of the site history; the subsurface conditions based on borings, instrumentation, a geophysical survey, and laboratory testing; slope stability analyses including alternatives assessment; and the pile design.SITE HISTORYS.R. 15 was originally located in the valley along the Tioga River and traversed through the towns of Tioga and Mansfield. Although the reason is unknown, it is interesting to note that Old S.R. 15 curved away from the river in the area of the landslide. In the mid 1970’s, S.R. 15 was relocated to the eastern hillside prior to construction of the Tioga-Hammond Reservoir by the U.S. Army Corps of Engineers. The relocated highway was constructed in stages. Two lanes of relocated S.R. 15 were initially constructed to carry one lane of northbound and one lane of southbound traffic. At this same time, the majority of the fill was placed for two future lanes immediately to the west, which would eventually allow for two lanes in each direction. The two eastern lanes would then carry northbound traffic after completion of the two southbound lanes to the west."

Jan 1, 2015

By G. C. Gester

With the exception of exploration geological work that is being prosecuted in various parts of the mainland of Arabia, the only new developments in Arabia during 1934 were on Bahrein Island, which is in the southwestern portion of the Persian Gulf, approximately 25 miles from the mainland of Arabia. Here the Standard Oil Co. of California, through its wholly owned subsidiary, The Bahrein Petroleum Co., Limited, has continued to carry on a systematic drilling campaign and has constructed camps, pipe line and marine loading facilities. During 1934 eight wells have been completed at depths ranging from 2058 to 2253 ft. These wells have shown average initial productions ranging from 1500 to 5000 bbl., with one, No. 15, estimated as being capable of flowing as much as 11,000 bbl. per day. The oil is asphaltic in character and has a gravity range of from 32' to 34' A.P.I. The locating of all new wells has followed a plan of orderly development, with the ultimate object of obtaining efficiency of operation and maximum production. The wells are taking a penetration of 200 to 250 ft. of the lower or so-called Main productive zone. The upper oil zone, which is cased off, includes 300 to 400 ft. of alternating limestones, clays and shales and carries a heavier oil under lower pressures. The Main zone is similar lithologically to the upper zone. Micro-fauna collected from cores have shown that the oil occurs in formations of lower Eocene and Cretaceous age. Development to date has not progressed sufficiently so that either the maximum thickness of the oil-bearing horizons or the limits of the field can be determined. Something over 10,000 acres has been proven to date. Among other developments leading toward the marketing of oil from Bahrein during 1934 was the construction of a marine loading terminal. This included the laying of over 3 miles of 12-in. submarine pipe line from the small island of Sitra out into the harbor, terminating in 50 ft. of water; also the laying of more than 10 miles of gathering lines from the producing area to the terminal. Three crude oil working tanks with floating roofs were erected on Sitra Island, having a capacity of 250,000 bbl. A pumping plant was provided having a capacity of 5700 bbl. of oil per hour. This is housed in a dustproof building, as rather severe

Jan 1, 1935

Two characteristics of the modern mining industry are that there is a skill shortage and that young professional people rise rapidly into highly responsible supervisory positions. With this responsibility comes the burden of identifying and managing health and safety risks. Without the benefit of a comprehensive health and safety training program, these young professionals may be putting both themselves and those under their supervision at risk. The Moura Mine explosions and the asbestos health disaster should not be just artifacts of history, but highly valued lessons that impress the need for comprehensive health and safety risk management strategies on young professionals. From the perspective of the former secretary of the Committee to implement the findings of the Moura (Disaster) Inquiry and as the former coordinator of the Coal Workers Health Scheme, key issues in occupational health and safety management systems are explored.

Jan 1, 2005

By Jack A. Caldwell

"This paper describes the nature of stage curves and the ways in which they have been used to study the construction sequencing of tailings impoundments. They provide a simple graphical method of representing the main aspects of an impoundment, studying the effects of different impoundment geometries, and predicting and controlling impoundment operations.IntroductionThe designer o f a tailings impoundment must, at all stages of design, examine the relations hip between the volume o r tones of tailings that will be deposited at the impoundment, the height to which the tailings will rise in a given time and that rate at which the various parts of an impoundment will be constructed. The operator, if he is to keep proper control of this impoundment, must be able to examine the effect of different deposit ion rates at the impoundment, and the consequences of placing more or less tailings at different parts of the impoundment. The operator must be able to see at a glance just how much higher an impoundment will be at the end o f the following yea r of deposition, and this he must be able to do in order to formulate his annual construction and operating plans.Stage curves are the best way o f modeling an impoundment. The simple impoundment model represented by the stage curves enables the designer and operator visually to examine the relationships between the various factors, such as impoundment volume, deposition rat e and construction rate, that dictate the essential features o f impoundment design and operation.A design model for a tailings impoundment may be formulated as in Figure 1. This involves the site selection process, the definition o f a geotechnical model, a water balance model and a height-capacity-production model."

Jan 1, 1983

By John B. Jones

New concepts in shaft kiln processing are included in the design of two large diameter shaft kiln plants now under construction. One kiln will be used to produce cement clinker at the Boettcher plant of the Ideal Cement Company at Fort Collins, Colorado. The other kiln is for the semi-commercial oil shale plant for Petrobras, the Brazil National Oil Company at Sao Mateus do Sul, Parana, Brazil. Investigations on application of the new concepts are proceeding in a portable pilot kiln. The shaft kiln has long been recognized as a method of gas-solids contacting having the following principle advantages: l. High thermal efficiency 2. Ability to handle a variety of feed materials with a wide range of particle sizes 3. Minimum investment and operating cost

Jan 1, 1963

By A. D. Thomas, V. N. Rampton, S. Paradis, C. F. Gleeson

"A shallow till sampling program was completed on a 1 km grid over the St . George Batholith in southern New Brunswick. The ""B"" soil horizon was analyzed for Cu, Pb, Zn, Ag, Co, Mo, U and Sb and the heavy minerals from the ""C"" soil horizon were analyzed for W, Sn and A u. The results delineated four of five recorded W occurrences, three of four recorded Mo occurrences, all recorded Cu occurrences and one recorded Au occurrence. The results indicate that shallow till sampling in conjunction with bedrock and Quaternary mapping can inexpensively define exploration targets in terrain similar to that underlain by the St. George Batholith.A similar program was carried out in eastern Ontario involving the analysis of four separates from the till, the ""8"" soil horizon, the -50 mesh fraction, the -250 mesh and the heavy mineral fraction of the ""C"" soil horizon and humus. Also sampling was carried out near known gold occurrences at closer spacings. Regionally, anomalous results from all sample media clearly defined a large auriferous shear zone and associated splays. Over one known showing all media clearly defined the showing and a secondary zone. On the regional scale the heavy mineral fraction gave the best anomaly definition and contrast, but the -250 mesh fraction was found to be the most cost effective for defining exploration targets. For detailed surveys, humus was found to be cost-effective."

Jan 1, 1986

By S. J. Pearce

The Bureau of Mines has prepared, as circumstances have dictated, a series of schedules setting forth the minimum requirements that various types of equipment should meet to be considered safe and satisfactory for use under certain hazardous or unhealthful conditions. These schedules cover a wide variety of devices ranging from explosives to electrically operated mine locomotives. This paper discusses the functions and operations of schedules under which respiratory protective devices are tested and approved. It emphasizes that the aim of the Bureau respirator-approval system is to make available to the public respirators that meet definite performance requirements. The responsibility of the respirator manufacturer in pre-testing the device and in maintaining its quality after it is approved are explained. Aid is provided for the user in selecting the proper device for specific application, and a plea is made for better education of all concerned in the proper use of the devices. DISCUSSION Provisions have been made for testing and approving the following types of respiratory protective devices: Self-contained breathing apparatus,2/ supplied-air respirators,3/ gas masks,4/ dispersoid respirators,5/ and chemical-cartridge respirators.6/ These devices are tested at the Central Experiment Station of the Bureau of Mines in Pittsburgh, Pa. Self-contained breathing apparatus is tested by personnel of Health and Safety District B; other types of respirators are tested by the Branch of Health Research.

Jan 1, 1957

By C D. Rose

A review and summary of the results of 120 coal sampling system bias tests is presented. This review supports new methodology using multivariate statistics currently being considered by ISO TC27 SC4. The current difficulties with ISO 13909-8 are explained and the logic behind the current new working draft is discussed in detail. Bias was detected in nearly 36 per cent of tests reviewed, suggesting that much improvement is needed in designing, maintaining and monitoring the performance of sampling systems in order to avoid sampling bias.CITATION:Rose, C D, 2012. Bias testing of mechanical sampling systems for coal - A review of test results and call for use of multivariate statistical analyses, in Proceedings Sampling 2012 , pp 185-192 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By Jon Errey, Aleksandar Petrovic, Karl Haase

"Developing a gold deposit of this magnitude in the Amazonian jungle of Guyana posed many challenges. This paper describes not only the process & logistical challenges arising from the remote mine site location in a tropical environment with a local industry unaccustomed to recent large scale gold mining operations, but also the innovative technical solutions employed to address the unique ore body characteristics. The best examples of this approach were dealing with the initial high clay content saprolite ore from the development phase and primary mining pits whilst ensuring that the design also implemented the right method to deal with the future fresh rock in an environmentally sensitive habitat. In order to do this separate individual crushing flowsheets were generated, focusing on the specific material handling equipment that would be suitable to handle these various types of material and ensure high recoveries were maintained.INTRODUCTIONAurora gold mine is located in forested region of Guyana, 170 km west of capital Georgetown, and 130 km West North-West of Bartica, a settlement at the junction of the Essequibo and Cuyuni Rivers.The Aurora gold project (Aurora) is a 5,000 tonne per day open-pit/underground operation, which will produce a total of 3.29 million oz. gold – averaging 194,000 oz. per year – over an initial 17 year mine life. At the final investment decision in 2014 Aurora had a total resource of 6.54 million ounces in the measured and indicated categories (62.83 million tonnes at 3.24 g/t Au) as well as additional 1.82 million ounces in the inferred category (16.93 million tonnes at 3.34 g/t Au)."

Jan 1, 2016

Aspects and anomalies in the present Standard Specifications for Blended Cements which may have operated in Australia against the development of the greater use of Slag Blended Cements are noted. Estimates of slag and ash usage in Australia are given and the need for further research with local materials stressed.

Jan 1, 1979

By A. C. Richardson

[During the past two and a half sears the U. S. Bureau of Mines and the University of Alabama, with the cooperation of the different coal operators, have been making an extensive studs of coal preparation in the State of Alabama. Considerable time has been devoted to the studs of the washing characteristics of the Mars Lee bed and the various methods used In preparing from it a low-ash coal suitable for the manufacture of metallurgical coke. One of the phases of this problem is the utilization of middlings products from the washing plants. This paper gives the results of treating jig middlings on a coal-washing table at the Bureau of Mines laboratory at Tuscaloosa, Ala. The sample used was secured from the Sayreton washery of the Republic Steel Corporation, Sayreton, Ala. WASHERY PRACTICE The Mary Lee bed is very bony, and operators find it difficult to produce from this bed a washed coal much under 10 per cent ash. Experience has shown that in the preparation of a coking coal from the Mary Lee bed it is best to use a process which permits the recovery of a middlings product. Middlings are desirable because separation according to specific gravity is never perfect, and a middlings product makes possible a low ash in the primary warned coal without excessive losses of combustible in the refuse. The general washery practice on the Mary Lee bed is to crush the run-of-mine coal through some maximum screen size and wash it upon some one type of jig without re-treatment of any of the products made. The maximum size treated varies from 3 inch to J inch. The middlings product from multiple-cell jigs is usually termed "boiler fuel" and when possible is utilized as such. At present the production of boiler fuel is often in excess of power requirements, and the surplus, due to its high ash content, becomes waste.]

Jan 1, 1931

By Alfred H. Bell

The year 1936 in Illinois was marked by considerably increased activity in drilling, both wildcat and proved territory, in leasing, and in seismic and geologic exploration. Of the 92 oil and gas wells completed during 1936 in Illinois, 49 were oil wells, 3 were gas wells and 40 were dry holes. This compares with but 34 completions in 1935. The total of the daily initial productions of the new oil wells was 1755 bbl., or an average of 36 bbl. per well. One new field was discovered, the Bartelso field in Clinton County. The leasing of some large blocks of acreage in Clay, Marion, and other counties by the Carter Oil Co. in the late fall of 1935 was followed in 1936 by extensive leasing in southern Illinois by 10 major companies and many smaller companies and individuals. It is estimated that 2½ million acres were under lease by the end of 1936. Seismograph surveying has been carried on by about seven companies, and the number of seismograph parties operating in Illinois has varied from six to eight throughout most of 1936. It is estimated that approximately two million dollars has been spent in the state in seismic and geologic exploration and in leasing during the last quarter of 1935 and all of 1936. Production of crude oil in Illinois in 1936, according to the Bureau of Mines, was as follows: Barrels Barrels January...................... 325,000 July........................ 402,000 February..................... 294,000 August..................... 380,000 March....................... 396,000 September.................. 386,000 April......................... 347,000 October.................... 393,000 May......................... 389,000 November.................. 363,000 June......................... 383,000 December................... 387,000 4,445,000 This 4,445,000 bbl. was an increase of 3 per cent over 1935. Although this increase was due largely to the fact that production was not artificially curtailed, it also reflects some new production and some increases in production from repressuring and water-flooding, which offset the

Jan 1, 1937

By A B. Christie, R L. Brathwaite

Since the first occupation of New Zealand in 800 - 900 AD, various useful minerals, rocks, and energy resources have been identified and extracted. The Maori prized greenstone for ornaments, tools, and weapons, used argillite and obsidian for tools, and decorated their carvings and bodies with colours made from clays, limonite, and vivianite. They were aware of coal (waro), but are not known to have used it for fuel. Before 1840, visiting whalers used coal from Shag Point to heat their trypots. Mining activities got underway in the 1840s, with the finding of manganese oxide deposits in the Bay of Islands, Kawau Island, Waiheke+ Island, and Taieri Mouth. Secondary copper ore was mined on Kawau Island (1846 - 1869), and native sulphur was exported from White Island to Europe. The discovery of gold at Coromandel in 1852 and a few years later in Northwest Nelson and Otago opened the way to gold rushes in these areas and subsequently in Marlborough and Westland. Mining of alluvial gold evolved through sluicing to the invention of gold dredges; first (1863) was the simple spoon design, but later (1881) large steam-powered bucket-ladder machines weighing around 3800 tonnes were built. Most of the gold dredges had gone by the early 1960s, following a revival in the 1930s, but one large dredge operates today on the Grey River. Other mining events included: underground mining of coal from 1849 and underground mining of lode gold from 1863 in the Coromandel, Reefton, and Otago fields. Most outcropping coal deposits had been discovered by 1870. Building stones were used by the early settlers for construction of houses, churches, banks, public buildings, and some universities from 1836. Aggregate for roads, railway ballast, and concrete, and limestone for cement and fertiliser, and clays for bricks and china have been quarried for many years.

Jan 1, 1993