Search Documents

By Maurício Gammertt Röhnelt

A pesquisa em questão trata-se do aproveitamento e aplicação da escória de aciaria elétrica, um subproduto residual do processo de refino do aço. A força propulsora para realização deste projeto está associada à utilização do resíduo: a quantidade gerada é maior que a quantidade aproveitada, uma vez que este subproduto tem como limitante de uso o fenômeno de expansão volumétrica que compromete obras de engenharia. No presente estudo, a escória foi micronizada, caracterizada e incorporada em uma matriz polimérica para obtenção de um novo produto com propriedades vedantes. Os artefatos produzidos foram submetidos a vários ensaios mecânicos, químicos e de caracterização conforme requisitado pela norma NBR 15750. Após a análise dos resultados, concluiuse que os compostos constituídos pelo resíduo apresentaram melhores propriedades vedantes que o grupo controle de referência. Além disso, verificaram-se melhores condições de processamento nos compostos com escória de aciaria micronizada. Obteve-se, portanto, um produto ecológico, mais viável economicamente, com propriedades que atendem a uma especificação. Dessa forma, difundiu-se a aplicação do resíduo para outros ramos industriais, agregando a este maior valor comercial, promovendo assim a sustentabilidade por meio da substituição de matérias-primas provenientes de recursos não renováveis pela escória de aciaria elétrica.

Aug 17, 2017

By J. B. De Hart

This paper has been confined to the consideration of the working of thick seams, from six feet to sixteen feet, which are pitching at about thirty degrees to the horizontal. The discussion has been limited to these set conditions because they are the ones of commonest occurrence in the Southern Alberta bituminous coal district, because, from the point of view of safety, thin seams are more easily worked, and because a discussion of all the possible combinations of thick and thin seams pitching at angles varying from zero to ninety degrees with the horizontal would involve a task impossible in the time available. It has been assumed that the mine makes gas freely and that the coal is friable and tends to make inflammable dust which is highly explosive. Since the problem requires the taking into account means of maintaining a high proportion of lump coal, it is further assumed that lump coal commands a price considerably higher than the price which can be obtained for run-of-mine or for slack coal. Figure 1, tabulating the various factors which must be considered and their relation to each other, indicates diagrammatically the complexity of the problem. Any method of working becomes divided into two distinct components, the active workings of the mine and the old abandoned workings. While these are in a measure distinct, they are nevertheless inter-related, as shown in the diagram.

Jan 1, 1930

This publication summarizes, for potential contractors and all other interested parties, the research and development of in-house and contract projects programmed by the Bureau of Mines for fiscal year 1983 (October 1, 1982-September 30, 1983) under its Health and Safety Technology program. The objective of these projects is to provide an ordered and sequenced series of advance toward the Bureau's overall goal of providing the systems technology required to create a more healthful and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1982

By Kanhaiya Mishra, Phanil. K. Mandal, S. K. Behera, P. S. Paul, Prashant Singh, C. N. Ghosh

The techno-economic and social benefits of cemented paste backfill (CPB) resulted in its wide acceptance by the mining industry. The Ordinary Portland Cement (OPC) remains the key binder but to diminish its economical constraints, suitability of alternate binders has been examined worldwide. The present study aimed to investigate the effect of partial replacement of OPC with fly ash on the CPB’s strength and to determine the most optimal mix to achieve the required strength (1 MPa at 28 days of curing) at the most cost-effective way using the Bayesian network (BN). The CPB mixes were prepared at 72 wt.% solid concentration with mill tailings (87–91%), OPC (6–13%), and fly ash (0–4%), and instantly after mixing, fresh (slump, bleeding, density) CPB properties were measured. The strength was tested at 7, 14, 28, and 56 days of curing and initially analysed through traditional model. The traditional models follow the aleatory principle and are considered not appropriate for geotechnical engineering. Hence, the BN model was developed and tested. The reliability of two classifiers in learning model structure was compared which gives Naïve Bayes as the highest reliable tool. The CPB’s strength is most sensitive to the OPC content. The most consistent mix(s) is mill tailings: 87–88%, OPC: 9–11%, fly ash: 1–4%. Adding fly ash at 89–91wt% mill tailings possesses high failure probability of the CPB. The collinearity test indicates that the fines percentage and chemical composition of CPB’s ingredients are highly correlated with its slump, bleeding, and strength development.

Jul 14, 2022

By Bill Linville

During calendar year 1972, the Bureau of Mines was engaged in some 20 major areas of research for the development of new and improved efficient methods of conservation and utilization for petroleum and natural gas, oil shale, and coal. Made up of numerous projects described in this report, the program was carried out through research performed at research centers and laboratories in the field supervised and supported by administrative personnel of this Bureau of the Department of the Interior. Based un this research, 186 technical reports were published by the Bureau or others, and numerous other reports were prepared for Federal agencies, State agencies, and organizations engaged in cooperative research programs with the Bureau.

Jan 1, 1973

By Chen-Ming Kuo, Esher Hsu

"The importers and manufacturers who import or produce products with packaging containers are charged a recycling fee in Taiwan. The amount of waste packaging containers used for calculating the recycling charge is based upon the amount declared by importers and manufacturers which might be underestimated. This study aims to estimate the amount of waste packaging containers generated by households in Taiwan and also explores its distribution. The sampling survey and ratio estimation are conducted for estimating the recycled amount; while the refuse sampling method for municipal solid waste composition is employed to estimate the un-recycled waste packaging containers. The estimated total amount of waste packaging containers in 2011 generated by households in Taiwan is 696,511 m.t., of which, 79.49% of the waste packaging containers were recycled and 20.51 % were landfilled or incinerated. This study shows that the amount of waste packaging containers declared by importers and producers is underestimated around 20%.IntroductionWaste packaging containers including iron cans, aluminum cans, glass bottles, plastic containers, paper containers, aluminum foiled paper packs are officially announced to be recycled in Taiwan. In order to create the economic incentive for raising recycling performance, associated manufacturers and importers are charged a recycling fee to subsidize recyclers. The amount of packaging containers declared by importers and manufacturers is used for calculating the recycling charge and recycling rate. The importers and manufacturers might underreport their producing (importing) amount to pay less recycling fees. Therefore, the estimated waste packaging containers based upon the amount declared by importers and manufacturers is usually underestimated. Related previous studies about waste packaging containers recycling in Taiwan are done by Hsu and co-workers [1-4]. Hsu and Kuo [1] estimated total production values of recycling and evaluated the performance of recycling performance based upon the estimated production values. Hsu and Liu [5] provided a cost analysis of recycling for waste packaging containers in Taiwan. Bor, Chien, and Hsu [2] presented a market-incentive recycling system for waste packaging containers in Taiwan. Hsu and Kuo [4] provided an amending mechanism for product charge and recycling subsidy in response to the social economic changes for waste packaging containers recycling. Lee and Hsu [ 6, 7] explored the distribution, fee rates, and collection rate of waste containers. This study aims to estimate the amount of waste packaging containers generated by households in Taiwan and also explore its distribution."

Jan 1, 2014

By Guilherme Santos Garcia

Este trabalho tem por objetivo avaliar a sinterização a plasma do alumínio com a utilização da técnica Active Screen, em comparação com o processo em forno resistivo. Foi utilizado pó de alumínio atomizado, com granulometria entre 30 e 100µm, sendo misturado junto aos pós cerca de 1% em massa de estearato de zinco como agente lubrificante. Foram confeccionados corpos de prova com 13mm de diâmetro e 10mm de altura. A compressão dos pós se deu através de uma prensa hidráulica, de ação simples, utilizando pressão de compactação de 600MPa. O tempo te sinterização foi mantido em 60min a temperatura de 500ºC, utilizando atmosfera de nitrogênio. Foram realizadas medidas de densificação, antes e após a sinterização, medição de rugosidade e microdureza superficial, bem como análises em MEV da superfície das amostras. O processo a plasma se mostrou satisfatório, sendo capaz de produzir amostras com boa densificação. As medições de microdureza superficial evidenciaram valores semelhantes entre os processos, sendo a amostra sinterizada via plasma a apresentar menor variação de microdureza. Através da análise de EDS das imagens, foi identificada a presença de estearato de zinco em ambos os processos, evidenciado que a extração do lubrificante não foi totalmente eficaz. Ainda, houve uma leve redução da rugosidade no processo a plasma em relação ao convencional.

Aug 17, 2017

By S Morgan, L C Pagdalian, S Serdzeff, C Malaloy-on

It is widely accepted that mineral deposits are decreasing in metal grades. To remain profitable and meet market demand, mining companies are expanding their operations by increasing the tonnage treated. These expansions may include new concentrators with higher nameplate tonnages or upgrading the capacity of existing ‘brownfield’ operations. In many cases, the brownfield upgrade route is preferred as it is less capital intensive; however, brownfield upgrades are never straightforward and present many metallurgical and engineering challenges.For example, to increase feed throughput at a brownfield site, there will be a requirement to modify the mine development plan. This may result in the ore mineralogy varying beyond the current feed fluctuation range. To accommodate these ore variations, a combination of mineralogical analysis and small scale testwork can be used to develop a new process flow sheet to achieve the product recovery/concentrate grade requirements. In general, however, flow sheet development does not usually consider site specific layout constraints and equipment requirements. At sites where future expansions were never considered, taking this silo approach could lead to project delays and compromise the circuit design.Engaging an experienced technology partner ensures the nominated project team is involved throughout all stages and aspects of a given brownfield upgrade – from conceptual flow sheet development, through to detailed engineering, construction and commissioning. The recent Carmen Copper Corporation (Carmen Copper) circuit upgrade has been completed in technology partnership with Outotec. The circuit upgrade was extensive and included new equipment additions to the comminution, flotation and dewatering circuits. Carmen Copper’s intimate knowledge of the ore characteristics, in conjunction with a trusted, knowledgeable technology partner, facilitated a robust circuit design, and fast-tracked the project execution. This paper deals specifically with the flotation circuit upgrade and highlights the benefits to Carmen Copper of this holistic approach.CITATION:Morgan, S, Serdzeff, S, Malaloy-on, C and Pagdalian, L C, 2014. The benefits of technology partnerships during brownfield upgrades, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 471–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By W. H. Gauvin, N. J. Themelis

I N ADDITION to its practical importance in the beneficiation of iron ores and in direct-iron processes, the study of the reduction of iron oxides involves many aspects of challenging theoretical interest. The complexity of the reduction process combined with the fact that under different experimental conditions the controlling stage for the reaction may not necessarily be the same, has led experimenters in this field to a wide diversity of opinion regarding the reaction mecl1anism. As a rule, each investigation has been restricted to the study of one or two variables over a comparative]~• narrow range of experimental conditions, and consequently, it be-comes necessary to examine the significance of each published work in the light of the results of other experimenters in the field.

Jan 1, 1962

By J. E. Spurr

"Zinc Industry in BelgiumBy March F. Chase, Consulting Metallurgist, Bureau of MinesBelgium for many years was the principal spelter producing country of the world. Gradually its production was surpassed by that of Germany, and Germany in turn lost first place by the production in the 77ti.tad States. For the ten years previous to 1914, 21.6 per cent of the world's spelter was produced in Belgium. Of this production approximately 40 per cent was exported. A large percentage of the balance was rolled and of the shoots thus produced a considerable quantity was also exported.From an economic standpoint even before the war, the Belgian industry was in a unique, if not praoarious, position. Dependent upon foreign countries for ore and foreign markets for sale of products, smeltor was at a distinct disadvantage when compared with some of those of other localities. These disadvantages were partly offset by cheap coal and labor and by whatever there is of value in experience and what we may term for want of a better expression smelting tradition. However intangible this latter may be, it did have and has today an influence on commercial operations.One must not overlook the effect it will have on the revival of the industry. It may not be the determining factor but the fact that for so many years this industry flourished in Belgium, and played such an important role in the industrial life of the country will decide many operators to attempt to re-establish their operations.In 1913 the Belgian spelter plants produced 204,220 long tons of spelter or approximately 20 per cent of the world's production. During this year 500,000 to of ore were treated. The actual value of all of the products derived from treating sine ore amounted to 225 million frames."

May 1, 1919

By K. Clifton, K. Kar, M. Gautam, J. T. Jurewicz

"This paper describes the history of LDV measurements employed in research involving gas-solid flows. Much of the discussion deals with measurement techniques employed to obtain separate and simultaneous solid and gas phase velocities. Also, LDV based measurement techniques that arc used to obtain particle size and concentration information in conjunction with the velocity measurements arc presented.INTRODUCTIONThere are numerous examples of industrial processes in which the motion of a solid or droplet dispersed phase in a suspending gas phase is critically important. The applications range from spray droplets injected into combustion chambers to the understanding of the time release mechanisms of particles generated by dissolving pharmaceutical tablets. In many of these processes, the heat, mass, and/or momentum transfer between the dispersed phase and the suspending fluid arc the items of interest. In the past, much of the phenomena were characterized by empirical models derived from flow averaged measurements. Gradual developments in laser Doppler velocimetry (LDV), have provided researchers with an unobtrusive measurement technique capable of obtaining the particle size velocity and concentration with good spatial resolution.In the two decades that LDV instrumentation has been available, most of the uses have concentrated on single phase fluid flow measurements. The light scattered from seed particles small enough to follow complex fluid motions, including turbulence, is converted into velocity information. While the utility of this instrument in single phase flows has been demonstrated beyond question, the use of LDV in gas-solid multiphase flows has had a more gradual development. The measurements ·of interest in these flow regimes are usually the velocity of the suspending fluid as well as that of the dispersed particulate phase. Early investigators were quick to see the potential of this instrument for measurements in gas-solid flows. The interest soon expanded to the development of instruments that could also simultaneously measure particle size and concentration within a two-phase flow field.This paper tracks the historical development of LDV technology as applied to gas-solid flows. The techniques to measure particle velocity, size, and concentration arc treated in separate sections although much of the development occurred simultaneously. Finally, some unique applications conducted at West Virginia University and other locations will be discussed in the application section."

Nov 1, 1995

By Xiaocen Lu, Guowei Li, Jiantao Wu, Thang N. Nguyen, Andrew C. Amenuvor

"This paper investigates the effect of driving a group of 52 open-ended Prestressed High Strength Concrete (PHC) piles on an existing highway embankment based on field measurements of excess pore pressure and lateral soil displacement. Excess pore pressure due to pile driving increased with depth and decreased with increasing distance from the pile, influencing a distance of 43 pile diameters. For pile groups, the rate of dissipation of excess pore pressure decreased with increasing depth and averaged 79% in 20 days, during which maximum ultimate bearing capacity was not yet attained. Lateral soil displacement continued to increase for a period of time after the end of pile driving and this could have resulted in significant inclination of piles if pile installation was too quick and pile spacing was too small. Lateral soil displacement due to pile group decreased with decreasing distance to the existing embankment as a result of high soil density produced by the embankment loading. The results also indicate that the effect of pile group installation on the existing embankment is negligible.INTRODUCTIONPile driving can cause excessive lateral displacement of soil and heaving of the ground surface, which may adversely affect nearby structures. In addition, lateral deformation and excess pore water pressure resulting from pile driving can exert lateral pressures and vertical forces on the piles, and impact negatively on the project and its surroundings. Therefore, it is important to evaluate the influence of pile driving on the nearby structures as well as the project itself when expansion works are carried out.Recent years have seen some development in the application of field tests for studying soil disturbance due to piles, and these tests usually involves pore water pressure and lateral soil displacement monitoring during pile driving. Results of field experiments performed by Reese and Seed (1957) in San Francisco Bay Mud with instrumented piles showed that pile installation generated large pore water pressures at the pile surface, with only slight increase at a distance of 15 pile diameters away. The measurements indicated that the increase in pore water pressures can exceed the initial total overburden pressure. Holtz and Lowitz (1965) reported a decrease in undrained shear strength immediately after pile installation, which was largely recovered after full pore pressure dissipation for field measurements within 1.5–2 pile diameters from the pile surface. Hwang et al. (2001) presented results of large scale pile driving tests where maximum excess pore water pressure generated decreased rapidly with increasing distance from pile. The excess pore water pressure became negligible at 15 pile diameters from the pile. Their results also showed that lateral displacement of the ground decreased with increasing distance from the pile. Pestana et al. (2002) carried out full-scale closed ended pile tests in the Young Bay Mud deposit. Higher excess pore pressures were observed for points closer to the pile, which decreased with increasing distance from the pile wall. Exponential decay of excess pore pressure with time was also noted. An 80% dissipation of excess pore pressure was achieved for soils more than one pile diameter away from the pile wall between 50 to 80 days. Lateral deformation generally decreased with increasing distance from pile wall, whilst varying erratically with depth. Bozozuk et al. (1978) reported on soil disturbance due to driving of 116 concrete piles in sensitive marine clays in a construction project. Maximum pore water pressures after pile driving within the group, and 6m (20 pile diameters) from the group were over 35-40% of the total overburden pressures, and the influence of pile driving on pore water pressure at 20m away from the group was very small. Cooke and Price (1973) studied a 168-mm-diameter instrumented pile jacked into over consolidated London clay. Outward lateral displacements ranging"

Jan 1, 2016

This list is part of the long-range conservation program of the Bureau of Mines and is intended for use by those interested in the Bureau's publications dealing with oil shale and shale oil. The items included represent 51 years of research by Bureau of Mines employees on oil shale and shale oil and are available at any U.S. depository library. DISTRIBUTION U.S. Bureau of Mines report series contain both free and sales publications. An asterisk (*) designates publications for sale. Such publications can be obtained from Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402

Jan 1, 1969

By W. G. Matteson

The Gulf Coastal plain of the southern United States is that area bordering for a large part, the Gulf of Mexico and extending inland and northward to the main interior highland region. It is more or less V-shaped and includes the States of Florida, extreme southern Alabama, all .of Mississippi and Louisiana, the eastern and southern half of Arkansas, and the eastern, southeastern, and southern portions of Texas. While the contents of this paper apply to. the Gulf Coastal plain in general, they are intended to refer more specifically to that portion of the plain included between the 90th and 97th meridians, and the 29th and 33d parallels, an area that may be described geographically as comprising western Mississippi, all of Louisiana, part of eastern and all of south-eastern Texas. It is within this area that numerous and prolific oil pools have been developed during the last 17 years.

Jan 2, 1918

By Dennis S. Kostick

Salt is a universal mineral commodity used by virtually every person in the world. Although a very common mineral today, at one time, it was considered as precious as gold in certain cultures. This study traces the material flow of salt from its origin through the postconsumer phase of usage. The final disposition of salt in the estimated 14,000 different uses, grouped into several macrocategories, is traced from the dispersive loss of salt into the environment to the ultimate disposal of salt-base products into the waste stream after consumption. The base year for this study is 1990, in which an estimated 196 million short tons of municipal solid waste was discarded by the U.S. population. Approximately three-fourths of domestic salt consumed is released to the environment and unrecovered while about one-fourth is discharged to landfills and incinerators as products derived from salt. Cumulative historical domestic production, trade, and consumption data have been compiled to illustrate the long-term trends within the U.S. salt industry and the cumulative contribution that highway deicing salt has had on the environment.

Jan 1, 1993

By John B. Gayle

The coking time has considerable influence on the throughput of a coke oven, and for this reason a large number of papers dealing with the relationship between coking time and the different operating variables have been published. Although all factors known to influence the coking time have been studied, agreement has not been reached on several questions.2/3 Therefore, it appears worthwhile to evaluate any data that become available during investigations of the carbonizing properties of various coals and coal blends. Because it is expected that reports covering several different phases of this problem will be forthcoming as additional data-become available, the following study of the relationship between coking time and bulk density represents a report of progress on the overall investigation of factors influencing the coking time in slot-type ovens. The practice of including coarse coal in the blend going to the ovens to obtain increased bulk densities is well known. Similar increases have been realized by adding small quantities of oil to the coal mix. Although it would appear that such procedures provide inexpensive methods for increasing the capacity of existing coke-oven installations, Ramsburg and McGurl4/ point out that this increase is possible only if the additional coal can be carbonized in the same coking time as regularly employed without using abnormally high flue temperatures. This statement is in substantial-agreement with the position of Auvil and others5/ and implies that any change in bulk density may be accompanied by a corresponding change in coking time. On the other hand, a recent review of proposed methods for calculating the time required for carbonization6/ includes a number of equations that completely ignore the effects of variations in bulk density.

Jan 1, 1954

By Gautam Chandra Mondal

An attempt has been made to carry out qualitative assessment of mine water discharges from the different mines of West Bokaro Coalfields of Hazaribag district of Jharkhand, India. A total of 33 mine water samples were analyzed for pH, electrical conductivity (EC), major cations (Ca, Mg, Na, K), major anions (HCO3, SO4, Cl, NO3), and heavy metals (Fe, Mn, Cu, Zn, Pb, Cr, Ni, Co, As). The hydrochemical data has been evaluated in terms of major ion chemistry, solute acquisition processes and suitability of mine water for domestic, industrial and irrigation uses. The pH of the analyzed mine waters varies from 5.27?8.43 indicating acidic to alkaline nature of the water. The electrical conductivity (EC) values varied from 276 µScm-1 to 1598 µScm-1 for measured samples and spatial differences between the EC values reflects the wide variation in lithology, surface activities and hydrological regime prevailing in the region. The anion chemistry of the analyzed water samples shows the dominance of SO4 and HCO3 with a minor contribution from Cl, NO3 and F. The observed high values of sulphate in the mine water of the area may be attributed to the oxidative weathering of pyrites. On average chloride is contributing 5% of the total anionic balance (TZ-). Fluoride and nitrate have low concentrations and on average contributing <2% the total anions. The cation chemistry indicates that 79% of the samples are Ca>Mg>Na>K, while the 6% belong to Ca>Na>Mg>K and 1% of Ca>Mg>K>Na. Weathering of rock forming minerals and cation exchange processes normally control the levels of these cations. Concentrations of some heavy metals (Fe, Mn, Ni, Cr) are found to be well above the prescribed permissible levels recommended for the drinking water. The water quality assessment for drinking purposes indicates that most of the mine water having high TDS, total hardness (TH) and sulphate concentrations. This suggests that mine water of the study area is not suitable for direct use in drinking and domestic purposes and needs a proper treatment before its utilization. The assessment of water for irrigation uses show that the water is good to permissible quality and can be used for irrigation uses. However, high values of salinity, %Na, SAR, RSC and Mg-hazard at certain sites restrict its suitability for agriculture uses. Keywords: mine water; ion chemistry; quality assessment; West Bokaro coalfields

Sep 1, 2012

By A Dal-Corobbo, R Zick

The coal mining industry is now faced with new regulatory requirements that limit the discharge of chlorides into receiving streams. To meet these new regulatory standards for treated mine water, a zero liquid waste approach was developed using advanced treatment technologies. The approach described in this paper will generate clean water for reuse in various energy endeavours or discharge to the environment, with no substantial liquid or solid waste from the treatment process leaving the site.CITATION:Dal-Corobbo, A and Zick, R, 2013. Zero liquid discharge in coal mining operations, in Proceedings Water in Mining 2013 , pp 221-226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Floyd C. Bossard

In underground mining operations, the over- riding issue has to be protection of worker health and safety. The employees underground, making a living in a dangerous occupation, know these are major issues. These men bargain their lives and health on the presumption that the operating management knows its business, and they, the underground employees, can pursue their occupation with the assurance that management has provided a safe and healthy ambient underground environment. When management assumes the mantle of protection of underground workers, it has to be positive that qualified engineers have designed the project, and that capable operating personnel are in charge and always available. Those persons with these responsibilities must be knowledgeable in the engineering and occupational health aspects of sine ventilation. The ultimate function of a mine ventilation system is to provide a comfortable, healthy and safe ambient environment for the underground workers. The attainment of these objectives has been complicated with the increased application of electrical equipment and diesel-powered mechanized mining equipment underground (discharging toxic diesel emissions); increased production rates with the attendant increased production of airborne dust; and mine development in increasingly hostile mineral formations containing combustible strata gases, radon gas emissions, along with high heat and humidity. In general, the modern mechanization of present mining operations has resulted in a sore complex set of problems for the engineer planning the underground ambient environment.

Jan 1, 1983

By David Dye

Good morning, everyone, and thanks Syd for that fine introduction. I am honored to be here to help you celebrate 25 years of advancement and success in the important field of ground control. I would also like to recognize Dr. Peng for his significant contributions in longwall mining and ground control. His contributions have had a major impact on improving safety and reducing fatalities in America?s mines. Thank you, Dr. Peng, for the important work you have carried on throughout the years. Many miners are alive today because of your dedicated work to protect them.

Jan 1, 2007