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By D. Y. Jiang, X. S. Tan, S. S. Peng

Expansion strain and stress that exist in floor rocks and that are due to the presence of water, were derived from a basic theory of mechanics. The results indicate that water stress and strain are the important factors that cause failure of the floor rocks and induce floor heave.

Jan 1, 1994

By Robert S. Neil, O&apos

The basic transportation planning process consists of: 1. Inventories and analyses of existing conditions. 2. Estimates of future growth. 3. Determination of future travel demand. 4. Testing alternative systems to satisfy future travel demand. The many modeling techniques used in the transportation planning process are well known, commonly accepted, and thoroughly described in readily available literature. This paper will concentrate on the fourth step of the planning process, specifically the development of alternative systems for testing, and will discuss some of the factors which should be considered during the development of alternative systems. There are many factors which require consideration and which have a bearing on the configuration of alternative test systems. These comments will be limited to the influence of geographic, demographic, geologic, and economic factors. Although addressed separately, the four are to a great extent related and have a significant effect on each other. The objective of examining these factors during the early phases of system planning is to assure that more detailed corridor studies will not be stymied by considerations which could have been anticipated and accommodated at an earlier time. It is particularly important that feasibility of construction be assured before test systems lead to corridor decisions and accompanying commitments to

Jan 1, 1974

By Colin Connors

Cemented rockfill is a key component in the success of underground mining at the Jerritt Canyon Joint Venture. The Murray and SSX mines are characterized by relatively poor rock mass quality, and the goal of complete mining recovery makes maintaining a high quality backfill product vital to the safety and efficiency of the mining operations. A large portion of the ore production from the Murray mine originates from drifting under backfill. Modelling studies performed to investigate induced loading of the backfill were used to develop engineering specifications for the backfill material. Operations history has shown an almost 100 percent stability of the backfill when mining is carried out beneath it. The volume of backfill required each year (approximately 300,000 tons) and the required cement content have a significant impact on the total mining costs. The potential for cost savings associated with higher replacement of cement with Type "C" fly ash and the implementation of a backfill strength management strategy were therefore evaluated.

Jan 1, 2001

By Joseph R. Hatch

During the past ten years detailed elemental analyses of approximately 8,000 well-documented samples of coils in the United States (including Alaska) have been produced by the U.S. Geological Survey and the various State geological surveys. Examples of data listings include Swanson and others (1976) Gluskoter and others (1977) Hatch, Affolter, and Davis (1979), and Wedge and Hatch (1980). These analyses serve as a basis for evaluating elemental abundances in coals from the various coal province, regions, and fields. When combined with additional geological and geochemical data, some of these analyses give insight into when certain elements were introduced into coals, and which physical and geochemical parameters are most important in determining coal elemental composition.

Jan 1, 1982

By D. A. Bulled

• "What does it look like?" - describes the appearance. • "How does it work?" - outlines the operation. e "Why does it work?"- explains the principles. • "What about controls?" - indicates possible automatic systems. • "How is it sized?" - discusses the necessary testwork and evaluation. • "What are the results?" - demonstrates test and operating results. • "What's the benefit?" - concludes with gains for the user.

Jan 1, 1999

By X. Wu, M. Karfakis, E. Topuz

The generalized ventilation network problems encompassing both natural and controlled splitting networks, is formulated using a nonlinear nonconvex programming model, which has not yet been solved satisfactorily. This paper presents a methodology which can deal with the problem. The proposed methodology converts the nonlinear problem into a linear problem, by using special ordered sets of variables, and optimizes it by a modified branch and bound technique. The global optimality of the methodology and its applicability to different cases are investigated

Jan 1, 1991

"INTRODUCTION Twin Metals Minnesota (TMM) (operating as a joint venture between Duluth Metals and Antofagasta PLC) assumed control of the property in 2010. Amec became involved with the project in 2011 and in 2012 incorporated additional drilling in order to update historic resource estimates. The Maturi geological model and resource estimate was updated in 2014 to incorporate additional information obtained during 2013 and 2014 drill campaigns. In 2017, Amec was purchased by the Wood Group and is now known as Wood. Geology The Twin Metals Minnesota (TMM) Maturi, Maturi Southwest, Birch Lake, and Spruce Road properties are located in northeastern Minnesota (Figure 1). This talk discussed the Maturi deposit only, although all four deposits share similarities. The following geology is summarized from Peterson and Severson (2002).Maturi lies within the Superior Province of the Canadian Shield which is exposed in central and northeastern Minnesota and extends northward into Ontario. In eastern Minnesota, the Midcontinent Rift System developed during crustal scale extension in the Mesoproterozoic Era. The rift system is traceable, as exposures of mantle-derived tholeiitic to subalkaline mafic lava flows, intrusives, and rift-filling fluvial sedimentary rocks, and in the subsurface as a gravity anomaly (high), from the eastern end of Lake Superior, arcing west across the lake basin, and extending south-southwest to northeastern Kansas. Intrusion of the Duluth Complex, circa 1,108 - 1,099 Ma, was related to rifting and is co-genetic with the North Shore Volcanic Group mafic volcanic rocks that form the hanging wall of the Duluth Complex to the east. Cu-Ni-precious metals (PM) mineralization including Pt, Pd, Au and Ag within the Duluth Complex is hosted by mafic to ultramafic intrusive rocks that are part of the overall intrusive complex. The Duluth Complex is defined as a more or less continuous mass of mafic to felsic plutonic rocks that extends northeastward for more than 170 miles (275 km) in an arcuate fashion from Duluth nearly to Grand Portage in Minnesota. It is bounded by a footwall of Paleoproterozoic sedimentary rocks and Archean granite-greenstone terranes (Peterson and Severson, 2002), and a hanging wall largely of comagmatic anorthosite, rift related flood basalts, and hypabyssal intrusions of the Beaver Bay Complex. Mineralization is hosted in the basal mineralized zone (BMZ) of the South Kawishiwi Intrusion (SKI). The SKI magmas intruded sub-horizontally between hangingwall Anorthositic Series (AN) rocks and footwall granitic rocks of the Neoarchean Giants Range batholith (GRB). The Maturi local geology and the deposit footprint (shaded orange) is shown in Figure 2."

Jan 1, 2018

By K. -A. Björkstedt

INTRODUCTION Strassa lies in the central part of Bergslagen, a tradi¬tional mining district, on the eastern side of the Stora Valley at an elevation of about 200 m above sea level. A railway siding runs between the mine and the Stora railway station from which there are railway connections to the shipping port and iron and steel works in Oxelosund, about 224 km away. The distance to the provin¬cial capital Orebro is about 60 km. The climate is typi¬cal for this part of central Sweden and is illustrated by the diagram of monthly precipitation and temperatures for the years 1968-1975 (Fig. 1). HISTORY There is no certain information as to when the Strassa mine was first worked, but it is known from sur¬viving accounts of mine inspectors that there were smelt¬ing works in operation in nearby villages in the 12th century. An example is the Gusselhytta ore smelting works, 10 km south of Strassa, which dates from this period. Around the year 1540 there were two smelting works in Strassa, the Upper Karberg and Lower Karberg works. Ore for these smelters was probably taken from Strassa and from the adjacent Blanka mine. In the year 1624 Strassa is mentioned by the painter Jons Nils Krook in an account of the iron mines in the Linde mining district (Linde Bergslags Jarngruvor). Several mines were listed in the area, the deepest being about 30 m. An impressive power installation is mentioned in 1639, including a piston system of lashed poles for transmit¬ting power from the Stora River to the Strassa fields. Its length was 2670 m. Common ground comprising about 20.2 km2 (5000 acres) of forest was allocated in 1689 for the furtherance of mining operations. Until the beginning of this century only the rich cen¬tral parts of the ore body were mined and these yielded, after handpicking, lump ore suitable for smelter feed. An example of the ore grades from these early times is an analysis of ore from the "Big Mine" (Storgruvan) from the year 1873: 48.5% Fe, 0.008% P, and 0.06% S. This same year a total of about 18 000 t was ex¬tracted from the Strassa mine. OWNERSHIP The mine was owned and run until 1874 by a min¬ing association made up of 119 so-called "bergsman," who were homesteaders often engaged in agriculture and timber-cutting as well. In that year the Strossa Grufvebolag (Mining Co.) was founded. In 1906 it was con¬verted into a joint stock company, the Strossa Gruveaktiebolag. This was acquired in 1907 by Metallurgiska AB for the implementation of Gustav Grondal's beneficiating and briquetting methods, for which the Strassa ore was well suited. The same year saw the completion of a new ore dressing plant with an annual production of 46 000 t of ore concentrate. In 1911 the mine passed to new hands, and in 1913 it was purchased by an Austrian company. Extensive new installations were made and in 1915 a new dressing and briquetting plant was completed with twice the capacity of the old one. In 1917 the Strassa mine was acquired by Granges. Be¬cause of unfavorable business trends and technical diffi¬culties, mining operations were brought to a close in 1923. Pumping kept the mine free of water until 1933 but it was completely filled ten years later. Up to 1950 the surface buildings and installations remained intact but the large dressing and briquetting plant burned to the ground in that year. Today only the machine shop re¬mains from this earlier period of operation, now housing parts of the Mineral Processing Laboratory. The decision to take up mining operations again was made in 1955 and construction work began the follow¬ing year. Of the old installation, only the "southern shaft" could be used for some development drifting after it had been completed with a new headframe. Other¬wise, all the buildings and installations required for the operations had to be rebuilt. New installations ready by 1960 were office and personnel facilities, a new shaft and headframe, a sorting and concentrating plant, a macadam plant, settling basins, pump stations, and a railway and yard with transport equipment. The instal¬lation was completed with two plants

Jan 1, 1982

By Jamal Rostami

With the recent technological advances; Tunnel Boring Machines (TBM) have become a viable economic alternative to drill and blast in hard rock excavation. These machines are finding increasing use in underground mine development due to the potential benefits they offer. The successful application of TBM technology to mining depends on the selection of the most suitable equipment and cutting tools for the rock and ground conditions to be encountered. In addition to required testing and geotechnical investigations, cutterhead design optimization is an integral part of the machine selection to assure a successful application of the machines in a specific project. This paper presents and discusses the back-ground of TBM application in a mining environment and the lessons learned, the process of conducting site investigation and the necessary laboratory testing together with machine selection and performance estimation for TBM use III mine development.

Jan 1, 1997

By E. C. Ekedahl, R. J. Heath

Introduction Potassium, together with nitrogen and phosphorous, is an essential nutrient required for growth. Since all living things need potash, the major demand for potash - about 95% of the total - is as a fertilizer. Agricultural productivity has increased dramatically in recent times. This increase in crop yields requires substantial amounts of added nutrients to keep the soil fertile. It follows then that potash will always be in demand. There is no substitute. Other fertilizers that contain phosphorous (P) and nitrogen (N) are complementary and not competing products. Fireplace ashes (pot-ashes) have a relatively high potassium content. Their value as a fertilizer had been recognized for centuries. But today's potash industry did not begin until deposits of potassium-rich ore were discovered and exploited in Europe during the 19th century. Canadian potash development Potash in Saskatchewan was first recognized in 1943. It was discovered as a byproduct of an oil exploration program. But it was several years later before the existence of a major commercial deposit was acknowledged, and not until 1951 that the first attempt at development occurred. That attempt was unsuccessful. The shaft flooded and was abandoned. It did, however, demonstrate the need for new technology to penetrate the waterlogged Blairmore layer. This was eventually developed and the first mines were brought into production in the early 1960s. Once the technology was available, and the extent and quality of the potash beds became known, a number of companies proceeded to develop mines. By 1970, seven mines were in operation and three more were nearing completion. Combined, total capacity then was 7.6 Mt/a (8.4 mil¬lion stpy) K20. At that time, world potash consumption was about 15 Mt/a (16.5 million stpy). This increase in supply from Canada produced a large potential surplus that shattered the prevailing balance between supply and demand. Although world demand increased steadily throughout the 1960s and early 1970s, it was several years before world supply and demand were again in balance. Saskatchewan capacity has been expanded a number of times. It now stands at 10.7 Mt/a (11.7 million stpy) K20. Actual production has not approached this figure, however. Two new mines in New Brunswick have recently been built with a combined annual capacity of 1.2 Mt (1.3 million st) K20. Total Canadian capacity of about 12 Mt/a (13 million stpy) now amounts to 30% of world capacity. Central offshore marketing organization Canadian Potash Exports Ltd. (Canpotex) was created in 1970 as the offshore marketing organization for Canadian producers. Canpotex is owned by Saskatchewan producers and is their exclusive marketing organization for offshore business. Each company handles its own sales in Canada and the US, but all sales to other markets are handled through and by Canpotex. The Saskatchewan industry has an ore body of a size and consistency unmatched anywhere in the world. Large efficient mines have production costs that compare favorably with other producing countries. On the minus side, Saskatchewan is remote from most major markets. It therefore needs the ef¬ficiencies that stem from one organization that coordinates all offshore shipments and minimizes distribution costs. Agriculture guides potash market In the period following World War II, potash was a classic growth industry. World demand increased each year from 1945 to early 1970s. Since then, demand has been more erratic. Some years show substantial increases, but are followed by significant declines. For about the last decade, the pattern has been unclear and future demand has become correspondingly difficult to predict. North America and Europe together account for about 40% of the world potash consumption. In both areas, farming is characterized by surplus production, declining crop prices, and expensive government support programs. Under those circumstances, farmers respond by minimizing input costs. Fertilizer is one of the items they reduce. Potash is retained in the soil. It is possible to reduce potash application with no immediate deterioration in crop yield. The lower yields occur only when potash levels are depleted. So, farmers can econo-

Jan 12, 1987

By Aladar B. Dory

INTRODUCTION Practical experience in mines with known presence of radon daughters in the mine atmosphere in Canada and elsewhere shows that a very high concentration builds up in an unventilated dead end heading. As Holaday et al1 observed, even a minimal air movement results in a drastic reduction in radon daughter concentration. It is therefore obvious that the main objective of radon daughter control in the working environment is to design the ventilation system providing an optimized flow of fresh air into the workplace, resulting in acceptable climatic conditions and achieving radon daughter concentrations resulting in exposures as low as reasonably achievable. BASIC OBJECTIVES Large mining companies, having extensive material resources and professional expertise, have utilized elaborate electrical modelling in the design of mine ventilation systems as early as 1950 (coal mining industry in Europe) and with the advance of computer modelling techniques, their utilization in ventilation systems design is on the increase. Unfortunately, these methods are usually not available to small mining companies and even the large companies might not achieve the fullest benefit from utilizing them, if proper limiting factors are not considered in the modelling. When an evaluation of a ventilation system of a mine is undertaken in literature, a measure of the amount of air supplied underground per one ton of ore mined is used as an indicator of the efficiency of the ventilation system. Yet, even the greatest amount of air forced into the mine might not result in an acceptable working environment if a proper distribution of this air into individual working places is not achieved. The volume and the age of the air are probably the two most important factors in achieving acceptable radon daughter concentrations in the workplace, but other factors also have to be considered. DIRECTOR MINE - ALCAN, NEWFOUNDLAND FLUORSPAR WORKS ST. LAWRENCE, NEWFOUNDLAND, CANADA Ventilation To illustrate the effects of the design of the ventilation system on the control of radon daughter concentration, let us review the gradual development of the ventilation system of this mine from the earlier years of its development up until its final years of operation. This mine, located near the community of St. Lawrence on the south coast of Burin Peninsula was developed in the late thirties and reached full production by 1942. Unfortunately as was customary at that time, the only source of ventilation was a natural draft. The mine was extremely wet, and no significant attention was initially given to possible health effects of dust. It was not until the mid-fifties, when a number of cases of silicosis had surfaced, that de Villiers and Windish2 observed a significant increase of lung cancer incidence among the miners in comparison to its incidence among the general population of Newfoundland. Suspicions regarding radiation as a cause of the lung cancer were expressed, but it was only in surveys taken in late 1959 and early 1960 that Windish3 and Little4 established the presence of radon daughters in the mine atmosphere in very high concentrations. Windish, de Villiers and Hurley suggested that the most likely source of the radon in the mine was the mine water which dissolved radon during its passage through the granitic country rock in the surrounding geological area. This conclusion was confirmed by analyses of water from various areas of the mine by the Atomic Energy Canada Limited laboratories. The radon values in the samples varied from 4,240 to 12,850 pCi/L5. Following the discovery of the presence of radon daughters in the mine, the company took speedy action to install mechanical ventilation for the mine. The system was not designed as a total unit, but fans were installed rather on a trial and error basis. The basic system installation began in March 1960 and was completed by 1962. It remained basically unchanged with only minor modifications until August 1973 when a wholly new, redesigned ventilation system was implemented. A schematic section of the mine and its ventilation system for the period prior to March 1960 is given in Figure "A", for the period 1960-1973 in Figure "B", and for the period after August 1973 in Figure "C". The ventilation system prior to 1960 is not known. All workings of the mine were ventilated only by natural ventilation. If any measurements of airflows at different or any times of the year ever existed, no records have been preserved. The very minimal natural ventilation was augmented by "blowing" air from compressed air supply lines and exhaust air from drills. It is known that the compressor capacities of the mine were limited and therefore no significant air movement was probably created by the "blowing".

Jan 1, 1981

By Paul Basinski

The Northern Reese River Valley is in west-central Lander County approximately 31 miles north of Austin, Nevada in the north-central Basin and Range Province (Figure 1). Authigenic zeolites, which were previously undescribed in the literature, are voluminous in this small sedimentary basin. Uranium mineralization is also abundant in this study area. Until now, what we believe to be cause and effect have not been put together. X-ray diffraction, differential thermal analysis, and scanning electron microscopy reveal clinoptilolite, erionite, analcime, and minor chabazite to be present (Figures 2, 3). Assays show uranium to be present in thicknesses up to 0.7 meters at amounts up to 0.10% eU308. The sediments in the Northern Reese River Valley belong to the Mio-Pliocene Humboldt Formation equivalents. This formation consists largely of tuffacious lacustrine and fluviatile sedimentary rocks. Mudstone is the dominant lithology and intercalated thin zeolite strata (usually less than 0.6 meter thick) are present. Zeolites in the Northern Reese River Valley were diagenetically derived from rhyolitic glass deposited in a shallow, saline-alkaline lake under arid to semi-arid conditions. Clinoptilolite from the study area was K-Ar dated at approximately 4.7 + 0.5 million years which corresponds to Middle Pliocene age (Krueger and Basinski, in press). This age is further substantiated by Middle Pliocene mammalian fauna collected in the vicinity by Deffeyes (1).

Jan 1, 1979

By R. L. Teseneer

Pyrite samples from twenty-one locations in the North Carolina Slate Belt were analyzed for cobalt, gold, mercury, and nickel by atomic absorption spectrophotometry. The geographic distribution of relatively high values of certain trace elements in pyrite suggests that, in addition to gold, cobalt and nickel metallogenetic provinces are possible in the slate belt. Northwest trends of province boundaries may be genetically related to subsurface features rather than to surface geology. Within province boundaries gold and nickel exploration programs should be concentrated in areas containing intermediate to mafic tuffs, while cobalt may be more concentrated in argillites and phyllites.

Jan 1, 1979

By Armin C. Supp

Since 1975, about a dozen high capacity flotation plants have been installed in the Ruhr district. Depending on the size of the preparation plants, the design capacity of the flotation section is between 100 - 150 t/h. The flotation units generally comprise rougher and cleaner stages in which 5 to 6 or 4 to 5 agitators respectively are arranged in line. The unit volume allocated to each agitator is up to 16 m3. The type of flotation machines, the design of these plants and their instrumen¬tation and control equipment are described in detail. The run of mine coal in the Ruhr district is characterized by a wide variety of the volatile matter. Generally, a distinction must be made between coals with more than 30 - 35% V.M., which are preferably used in power station, and coal with lower V.M. content, which are preferably used as coke-oven feed. The difference between these coals in respect to grain-size distribution, ash cotent and flotation properties will also be described in detail.

Jan 1, 1985

By Hetland Donald L.

Regional Tertiary formations and basins of local sedimentation which contain uranium deposits west of the Rocky Mountains are mainly of Oligocene, Miocene, and Pliocene age (fig. 1). The host rocks have been derived mainly from intrusive and extrusive igneous rock. The major host formations which cover broad geographic areas include the Esmeralda, Truckee, Humboldt, Thousand Creeks, Payette, Panaca, Cedarville, Coso, and San Joaquin Formations. Local areas of Tertiary sedimentation containing uranium deposits occur near Yuma, Safford and Artillery Peak, Arizona; Dillon and Canyon Ferry, Montana; Spokane Indian Reservation and Pend Orielle River, Washington; Topaz Mountain, Utah; Stanley Basin, Idaho; and Sonora Pass, California. Uranium deposits in these sediments have been classified into five categories based on environment (fig. 2). They are: (1) Deposits in lake sediments consisting mainly of water-laid tuffs; (2) Deposits in lake sediments intruded by volcanic plugs; (3) Deposits in lake sediments interbedded with arkoses near batholiths; (4) Deposits in coarse volcanic sediments in local sedimentary basins; (5) Deposits in arkosic conglomerates in local sedimentary basins.

Jan 1, 1969

By Robert D. Schmidt

The Bureau of Mines is conducting an investigation to develop remediation techniques for residential water wells whose yield has been affected in the long term, by underground mining. Initial work relating to this project was conducted in 1984-1987 at a room and pillar mine in Indiana County, Pennsylvania. Piezometer nest data from the room and pillar mine reveals that a downward gradient in piezometric head exists in shallow strata as a result of drainage into the underlying mine void. The vertical gradient in head in turn results in well bore leakage in open-hole water wells. The relative yield of valley wells is only slightly affected however because the high surficial recharge rate through fractures more than compensates for fracture leakage into the underlying mine. The relative affect of well bore leakage on well yield is greater in certain hillside and hilltop wells that have comparatively low inflow rates at shallow depths. The static water level of such wells is determined to a much greater extent by the chance interception of deep outflow fractures, than is the case for wells drilled in a more intensively fractured valley bottom. The lower static water level of wells that intercept deep fractures does not necessarily reflect the water table conditions outside of a small radius around the affected well. The results suggest that permanently isolating well bore outflow fractures may remediate certain open-hole residential wells that have been affected by high extraction underground mining.

Jan 1, 1986

By Alan D. Hoagland

The Flat Gap Mine is on Copper Ridge in the Appalachian Valley of East Tennessee, Large zinc orebodies occupy zones of solution and collapse breccias in lower Ordovician Kingsport limestone and dolomite, The principal ore mineral is sphalerite and the principal gangue is dolomite, The orebearing horizons are considerably more than 95% covered by thick residual clay, and geochemical prospecting under these conditions is an effective exploration technique which played an important role in the discovery and exploration of the Flat Gap Mine, The residual nature of the over-burden at Flat Gap is emphasized, Background heavy metals (mainly zinc) range from 50 to 200 ppm, and the anomalies range to 3000 ppm and more, About 80% to 9W0 of the soil zinc is in relatively insoluble form in solid solution with the hydrous iron oxides and in the crystal lattice of the clay minerals. Quite discrete zones in the soil with sharply contrasting metal value boundaries mark vestiges of bedrock mineralization, and such anomalous soil areas are often contiguous with partially weathered ore. It has not been possible on the basis of chemical criteria to distinguish between an anomaly formed from non-commercial mineralization and one formed from ore.

Jan 1, 1962

By Karen M. Kessen

The isotopic variations of lead from Mississippi Valley galenas have long been used to place constraints on the sources of the lead, and on the residence the of the lead in crustal reservoirs prior to its emplacement in the Mississippi Valley province. Similar studies based on strontium isotope variations in gangue minerals associated with the lead-zinc sulphides have been neglected until Haden's (1) study of such minerals from several localities in northwestern Ohio. His work revealed two things about the mineralization. Firstly, it shoved that the average isotope composition of lead from galenas from northwestern Ohio lies on the anamalous lead line characterizing Mississippi Valley-type leads, albeit at the least radiogenic end of the entire data array. This confirm earlier assignments of the Ohio mineralization as Mississippi Valley-type (Hey1 and others (2)). Secondly, Haden (I) showed that the strontium in the calcite, strontianite and fluorite is broadly similar in isotopic composition to the strontium in the host Silurian to Devonian marine carbonates within which these minerals arc emplaced. He concluded that the mineral strontium my have been very locally derived, from the carbonate hosts.

Jan 1, 1979

By C. J. Webb

Column experiments were performed to determine the ability of Madison aquifer material to adsorb arsenic and other constituents in a heavily mined watershed of the Black Hills in western South Dakota. The Madison aquifer is a karstic dolomite and limestone reservoir that is exposed on the flanks of the Black Hills. Streams that cross the Madison in the eastern Black Hills typically lose all their flow to the aquifer at sinkholes. In this work, Madison aquifer material was obtained for loading of six-inch diameter columns, which were backfilled with Madison aquifer water. Stream water then was allowed to displace the aquifer water during column testing in order to simulate mixing of the two waters at sinkholes and to determined adsorption of arsenic and other dissolved constituents. Initial results show that some adsorption of arsenic occurred when compared to more conservative tracers such as nitrate.

Jan 1, 1999

By N. Zouridakis

Radon is an established lung carcinogen and remains the most important environmental radiation exposure. It was estimated that inhalation of radon and its short-lived decay products accounts on average for about one half of the effective dose equivalent from all natural sources of radiation. Radon contained in household water can transferred into room air as a result of agitation or heating. An indoor air concentration of 400 Bq/m3 is obtained if the radon concentration in household water is 4 kBq/L. A typical concentration of radon in ground water is about 1000 times lower than this concentration but sometime elevated concentrations of some kBq/L in ground water are reported. In this work a Liquid Scintillation counting system is used to obtain fast and accurate measurements of radon (222Rn) in water samples from Argolida, Greece.

Jan 1, 2007