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By C. D. Taylor, A. L. Mazzella, A. L. Martikainen

In fluctuating airflow, continuous air velocity recording is the most reliable method of air velocity measurement. It allows for fast recognition of changes and the calculation of long-term averages. Also, it enables the mine operator to identify when the airflow has decreased to a point requiring action. Using ultrasonic anemometers provides an accurate option for continuous air velocity monitoring. This paper provides information about the effect of common obstructions in underground mining on air velocity readings. Stationary and moving obstructions are used to represent workers and equipment that would cause discrepancies in measured airflow. Also, it is important to know how large of a sample size is required to ensure reasonable accuracy of results. Statistical analysis is used to evaluate the required sample size. The sampling procedure is further studied by comparing two different sample rates. The results show that obstructions provide noticeable differences in air velocity measurements. Also, movement of obstructions can be recognized from changes in results. Surprisingly small sample sizes provide reliable air velocity information. Standard sample rates are found to be suitable for the underground environment.

Jan 1, 2011

By James W. Mahar

The following paper summarizes our observations on building response to mine subsidence and techniques for mitigation of building damage. The subsidence cases are located in Illinois. The general description of the geologic and mine conditions are primarily for those sites. Data on building response and mitigation measures were collected under grants supported by the Abandoned Mined Lands Reclamation Council (AMLRC) of Illinois and the U. S. Bureau of Mines, in Twin Cities, Minnesota. Case histories include pit and sag subsidence primarily beneath abandoned room and pillar mines. The majority of the paper deals with structures affected by sag subsidence. Most of the structures are one and two story homes. The first section of the paper summarizes the typical geologic and mining conditions at the sites. Building response to pit and sag subsidence follows the first section. Emphasis is placed on the behavior of concrete and masonry foundations, and wood frame and masonry superstructures. The third section describes mitigation techniques used to prevent or minimize building damage. A summary of the observations and critical parameters is given at the end of the paper.

Jan 1, 1982

By Harry Verakis

Electronic detonator systems are an advance in technology beyond conventional electric detonators for initiating explosives and blasting agents. Their use is widening into the mining operations of the U.S.A. Each electronic detonator system differs in design, construction, operation, and testing features and each system is different than “conventional” electric detonators. There are benefits of electronic detonator systems which serve to improve blasting safety. With the introduction of electronic detonator systems for mine blasting, issues were raised about the application of MSHA regulations for shunting and circuit testing. The MSHA regulations for surface and underground mine blasting operations address the use of “electric” detonators. Although electronic detonators are initiated by an electric pulse or current, their design is unlike “electric” detonators. To resolve the issues of shunting and circuit testing with respect to MSHA regulations, a technical and field evaluation of electronic detonators was made and the results are presented.

Jan 1, 2005

By A. E. Sears

The intent of geomorphic landform design is to mimic the function of the natural landscape. In a surface mine reclamation application, geomorphic landform design has the potential to mitigate stream loss. This research quantified features of reference landforms and performed computer modeling of a conceptual valley-fill design using geomorphic landform principles. A design was created using published design parameters with a software design tool (Carlson Natural Regrade with GeoFluv). Three additional designs, incorporating field-obtained regional geomorphic landform parameters, were completed and resulted in a geomorphic landform design specific to southern West Virginia. This work illustrates the importance of field determination of the ridge to head-of-channel input and drainage density parameters. Values of ridge to head-of-channel distance measured in this study were consistently an order of magnitude greater than software recommended values (SRV); SRV = 24 m (80 ft) versus field= 220 m (720 ft). Similarly, for the drainage density parameter, the software recommended range is 6 to 9 km-1 (80-120 ft/ac). The field measurements for central Appalachia quantified the drainage density to range from 5 to 5.3 km-1 (67-70 ft/ac). This affects Appalachian valley-fill stream construction by making the stream lengths shorter and the land slopes steeper with straighter headwater channels compared with areas in the southwestern United States. While the application of geomorphic landform design to surface mine sites presents challenges, this work provides support for future applications.

By Andrew C. Katen

The mining industry faces increasing geopolitical risk in the coming decades. Constraints such as resource nationalism, corruption and social license could grow to outweigh fundamental limitations like geology or supply and demand (Ernst & Young, 2013; Verrastro et al. 2010). Lurking beneath these more immediate and palpable concerns, however, may be more significant risks entrenched in geography and history. Deep-rooted cultural and strategic forces that emerge slowly ? or erupt suddenly and unexpectedly ? can generate momentous and far-reaching political, social and economic changes. While multinational enterprises routinely assess for political risk, the nature of minerals extraction means long-term and systemic geopolitical conditions are especially important for mining companies to identify and understand. Mine development is a decades-long process that binds companies to the land and makes changing course to avert emerging threats a difficult and costly option. Consequently, geopolitical assessment is a pertinent and valuable tool that mining companies can use to more comprehensively evaluate strategic threats and opportunities. Geopolitics is the study of society, politics and strategy through the lens of geography (Gray, 1996). Its emphasis on relatively permanent physical features of the earth makes geopolitics a uniquely valuable tool for assessing political risk. Topography, climate and natural resources have shaped, constrained and motivated peoples and governments throughout history. These influences transcend regimes, policies and borders ? and even states themselves ? which, by contrast, change often and dramatically. Framing politics against mountains, deserts and rivers supports identification of historical patterns and forecasts of emerging trends. In other words, the physical map provides an objective and consistent model for studying a subjective and dynamic subject such as politics (Sloan and Gray, 1999). Consequently, geopolitical assessment can highlight threats and opportunities that go unaddressed by other risk methodologies that emphasize current conditions (Glancy, 2012). Taken together, the permanence of geography, hindsight afforded by centuries of political history, and interconnectedness of world events makes geopolitical assessment a valuable approach for conceptualizing strategic risk.

Mar 1, 2014

By J. R. Patts, A. B. Cecala, E. J. Haas

Exposure to respirable crystalline silica (RCS) remains a serious health hazard to the U.S. mining workforce who are potentially exposed to RCS [1,2] as various ore bodies are drilled, blasted, hauled by truck, crushed, screened/sized and transported to their destinations. To examine a method for assessing RCS exposure using a NIOSH-developed video exposure monitoring (VEM) technology (referred to as Helmet-CAM), video and respirable dust concentration data were collected on 80 miners across seven unique mining sites. The data were then collated and partitioned using a thresholding scheme to determine exposures that were in excess of 10 times the mean exposure for that worker. Focusing on these short-duration, high-magnitude exposures can provide insight into implementing controls and interventions that can dramatically lower the employee’s overall average exposure. In 19 of the 80 cases analyzed, it was found that exposure could be significantly lowered by 20 percent or more by reducing exposures that occur during just 10 minutes of work per eight-hour shift. This approach provides a method to quickly analyze and determine which activities are creating the greatest health concerns. In most cases, once identified, focused control technologies or behavioral modifications can be applied to those tasks.

By J. J. Sammarco

Computer-aided control of a mining machine pl aces its operator in a safe, remote location, thus reducing health and safety risks, Sensing systems that provide machine position (xy coordinate) and heading (yaw), are extremely useful in aiding remote positioning of mining machines. The U. S. Bureau of Mines has developed two sensing systems for position and heading information: A scanning laser system based on the Lasernet sensor and a mechanical position and heading system based on linear-position transducers. The Bureau is also investigating a system from Honeywell, the modular azimuth and positioning system that employs ring-laser gyroscopes. This paper presents a brief background and status of these sensing systems as applied to the remote positioning tasks of a continuous mining machine. Included are field test results of each system operating in a room-and-pillar research section at a cooperating mine in West Virginia.

Jan 1, 1992

By J. P. Bunch

As the number of environmental laws continues to steadily increase and the economic penalties for contamination problems become more severe, environmental management represents an important management function within today's U. S. mining industry. The economic impact to a mining company for contamination is not only realized in legal fees and fines but also in the cost of doing normal business. For example, a mining company with contaminated property applying for a loan may be refused because of a lending institution's reluctance to finance due to liability concerns. Or, an insurance company may decide to greatly increase its annual premiums because of existing or potential contamination problems. One of the main duties of the environmental manager is to seek ways to reduce these types of problems by eliminating contamination or by knowing what problems exist and designing corrective measures to prevent the situation from worsening.

Jan 1, 1990

By H. I. Meyer

The mine is a large open-pit copper mine located near Tucson, AZ. Mining operations involve shovels digging at relatively fixed locations and haul trucks moving the muck to a primary ore crusher, a primary waste crusher, and directly to waste dumps. The total investment in shovels and trucks is some $100 million. Fig. l is a schematic drawing of the operation. A static method of truck assignment is used; i.e., each driver is given one particular shovel to serve until reassigned by the dispatcher. A dynamic system is one where trucks are reassigned after each trip. The problem is to compute a near optimum assignment of trucks for efficient operation.

Jan 1, 1979

By W. Jacobi

INTRODUCTION The radon problem concerns the radiation exposure from inhaled short-lived radon daughters and the associated risk for the induction or promotion of lung cancer. In several groups of miners which were exposed in the past to relative high radon levels during their underground work, an excess lung cancer frequency has been observed. On the basis of these findings it has to be stated that the inhalation of radon daughters is the most important radiation hazard in mining. Involved in this radon problem in mines are the difficulties to measure the individual radon daughter exposure of miners and to estimate the dose to critical cells and target tissues in the lung from inhaled radon daughters. And finally the reduction of radon levels in mines confronts us with special technical problems which are difficult to solve. Thus the setting of annual limits for the radon daughter exposure of miners alone is not sufficient to guarantee an appropriate standard of radiation safety. Of same importance are the improvement of air monitoring and the optimization of technical protection measures in mines. This has to be kept in mind for the following considerations on exposure limits. The ICRP has recommended in 1959 for the first time a maximum permissible concentration (MPC) for the occupational exposure to radon and its short-lived daughters (ICRP, 1959). This MPC in air was derived from a maximum permissible dose equivalent of 0.15 Sv (15 rem) per year to the epithelium of the large bronchi which was regarded as the "critical tissue". This old MPC-value was derived using a simplified lung model which paid main attention to the dose contribution from the inhalation of unattached 218Po(RaA) atoms. Since this time more realistic dosimetric models for radon daughters have been developed; some of these models will be presented in special papers on this conference. Furthermore in the last 10 - 20 years substantial epidemiological information on the lung cancer risk among several groups of Rn-exposed miners has become available. Taking into account these epidemiological and new dosimetric findings the ICRP has adopted in March this year new recommendations on occupational limits for inhalation of 222Rn, 22ORn and theirshort-lived daughters. This report will be published this year as ICRP Publication 32 (ICRP 1981). The recommended limits for radon daughters were derived from the basic dose and risk limits as they were proposed by ICRP in its new basic recommendations (ICRP Publ. 26, 1977). In the following this basic system of dose limitation is shortly outlined before the special recommendations for radon daughters are described. [BASIC CONCEPTS AND LIMITS] The new basic recommendation of ICRP (Publ. 26, 1977) proceed from the assumption that in the dose range which is relevant for radiation protection, the risk RT of so-called stochastic radiation effects (carcinogenic and genetic effects) in a target tissue T increases proportionally with the mean dose equivalent HT in this tissue: RT = aT HT. If several target tissues are irradiated the total individual (stochastic) risk is given by the sum of risks in these tissues: [R = ?TRT = ? T aT HT]. Thus this concept of individual health detriment takes into account the risk contribution from each relevant tissue. It replaces the old concept of the critical tissue, which neglected the exposure of other tissues. Applying this new concept a dose quantity can be defined which is proportional to the total individual radiation risk from stochastic effects. This so-called "effective dose equivalent (HE)" is given by the sum of the weighted dose equivalents in the relevant tissues: [HE = E wT HT with E wT = 1 T '1] The weighting factor wT of each tissues follows to wT = aT/awB, where awB is the total stochastic risk coefficient for a uniform irradiation of the whole body. For the lung as a single organ comprising several target tissues, the ICRP recommends a total weighting factor w = 0.12 (ICRP 1977/79). This concept of risk or detriment, respectively, has important consequences. To meet the objectives of radiation protection the new ICRP-system of dose limitation is based on the following three principles: 1) The justification of practices involving radiation exposures; no pratice shall be adopted unless it produces a net benefit. 2) The ALARA-principle that all exposures shall be kept as low as reasonably achievable; this requires the optimization of the level of protection. 3) The limitation of individual exposure (annual dose limits). It is important to note that the dose limits for individuals are only one part of this system of dose limitation. Furthermore, these limits cannot be regarded as a boundary between safe and unsafe. They have to be interpreted as the lower boundary of an unacceptable exposure region. This means that in addition to the observance of these basic dose limits it is demanded to optimize the level of protection. Consequently the optimized exposure levels or the corresponding operational limits will be normally lower than

Jan 1, 1981

By Brian Fulcher, John Eastlund, J. B. Copeland

Following the completion of the 7,600 m primary access tunnel by Kiewit/Parsons Brinckerhoff (K/PB) in April 1997, an exploratory East-West Cross Drift Tunnel was constructed at the Yucca Mountain Project over the proposed future repository block for high level nuclear wastes. The 2,681 m (8,796 LF) East-West Cross Drift Tunnel was excavated through volcanic tuffs having zones of incompetent rock using a re-built Robbins 5.000 m (16’-5”) hardrock TBM with a special arrangement of supporting equipment. Details of the unusual site and contract conditions will be discussed as well as with the unique tunnel equipment specified by the Owner. This portion of the Yucca Mountain project required eight months to complete.

Jan 1, 1999

By Y. Lizotte

The purpose of this paper is to describe a stochastic simulation program used to assess several dispatching rules applicable to small scale computerized systems for optimizing truck/shovel productivity. The system studied is semi-automated with a dispatcher communicating instructions by two-way radio. The simulation program is structured on an advance clock approach which enables the insertion of dispatching rules at various points in the haulage net- work. The rules tested include minimize shovel idle time, maximizing immediate truck use and assigning trucks to shovels to meet specific production objectives. A variation of the traditional "Match Factor" is implemented to maintain fleet balance throughout the shift. A mine case study demonstrates how the dispatching rules increase productivity of such semi-automated dispatching systems. Practical problems involved in the implementation of small computerized dispatching systems are also discussed.

Jan 1, 1986

By Brian Gettinger, Jim Schlaman, Alston Noronha

"INTRODUCTION The public understanding of green solutions today is based on the definition of sustainability adopted by the Brundtland Commission (World Commission on Environment and Development) in 1987: “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Over time this initial definition evolved to identify three distinct factors impacting sustainability that are often referred to as the “Triple Bottom Line”: Economic, Environmental and Social. The triple bottom line approach seeks to drive outcomes that create maximum value for all stakeholders. In the last ten years purveyors of water and wastewater tunnel solutions have found themselves on the wrong side of a politically polarizing issue in the crosshairs of politicians, environmental activists and community groups branding tunnels as expensive, “gray” and not-sustainable. Tunnels under design were stopped and large planned tunnel programs were delayed or canceled. Therefore being sustainable and “green” is not simply using natural vegetation, but creating an asset that meets current and future needs and will not become a future liability. As this paper will discuss, tunnel projects embody a sustainable triple bottom line project well, are equally sustainable as green infrastructure, and have begun to gain awareness for their sustainability. GREEN INFRASTRUCTURE CHANGES TUNNELING LANDSCAPE The green movement quickly swept across the nation in the mid to late 2000’s and was a hot topic in the media and at all the local, regional and national industry conferences. Politicians espoused the benefit of green infrastructure including job creation, urban renewal, aesthetics, property values economics and sustainability. The political microscope was focused the closest on stormwater and wastewater management, particularly in communities responding to combined sewer overflow (CSO) consent decrees from the Environmental Protection Agency (EPA). As communities with CSO problems evaluated their long term control program (LTCP), local government officials and planners began to balk at the huge price tag required for compliance and began looking for alternatives. “Green” infrastructure was proposed as lower cost solution that could be used to offset capital-intensive “gray” infrastructure like new sewers, storage tanks, tunnels, and treatment facilities. In addition, including green infrastructure in a previously negotiated LTCP required a reset on the entire planning process, additional studies and more planning which would push capital investment further off into the future, subsequently delaying unpopular user rate increases. As a result, tunnel projects as well as trenched conveyance and treatment plant projects that had not yet started construction were stopped, delayed or substantially changed."

Jan 1, 2016

By Harrison A. Schmitt

During .the past five decades or so we have passed from a time when it was difficult to point to a mine or an ore body and verify that it had been discovered by geological methods, through the. Twenties when the common saying was, "Who ever heard of a mine found by a geologist?", to recent decades when hundreds of mines and ore bodies are acknowledged geological discoveries and the above query can be ignored. Recently, however, the application of mining geology appears to have been downgraded, or so it seems to me. Basic geology in mining has been cheapened and glossed over in favor of geophysics and outcrop sampling, even though the latter is merely one technique of mining geology and, to some extent anyhow, has been used for a. long time. (Locke, 3, pp 81-87). Geophysics by itself and in conjunction with geology has had success in certain geological provinces, but limited attainment in mountainous terrane except in those few cases where strongly magnetic minerals are associated with ore. Nevertheless, in the Cordillera .many experimental techniques are offered as proved ones. This is not an intent to try to depreciate honest geo- physics. Continued experimentation and use of it is approved by all, but at the same time it is foolhardy to throw mining geology overboard, Generally both approaches should be considered and usually, at first anyhow, geology is the most direct one.

Jan 1, 1960

By W. C. Yates

Lack of visibility from large, open-pit haulage truck cabs has become a serious safety problem. Anaconda conducted a research program to develop a low cost system to alert haulage truck operators to small vehicles present in blind areas. Several systems were developed and tested. As open-pit haulage truck size has increased, so has the size of the blind areas. Mine utility vehicles, pickup trucks, and cars are concealed within these blind areas and become safety hazards. Figure 1 shows the typical blind areas of a 136 t (150-ton) haulage truck. The areas of greatest concern are at the rear center and front right corner of the truck. In these "no visibility" areas many small vehicles have been crushed by large haulage trucks at various mine sites. In most instances, the occupants escaped the vehicle before it was destroyed. But injuries and death have occurred. In most cases, the accidents were attributed to negligence or carelessness by the small vehicle driver. The limited visibility problem still exists, though, and a solution is needed. Initial Solution The usual plane mirror on the driver's side and the convex mirror on the right front of the haulage truck allow only limited rear visibility. The typical, right side convex mirror is generally small and difficult to locate at a glance. This convex mirror also presents an image that distorts distance perception. These mirrors are of¬ten broken and immediate replacement not demanded or made. The US Bureau of Mines, in a contract with M.B. Associates, San Ramon, CA, developed an improved visibility system. It consisted of a larger, left view mirror and unique, blind area viewer. The large 230 x 690 mm (9 x 27 in.) left mirror has a small convex spot mirror near the bottom. The entire unit can be quickly replaced if broken. The large size provides a full view of driver orientation features such as the rear tire and the top of the load bed. The right 300 x 410 mm (12 x 16 in.) mirror has a convex surface and is quite rugged. The 510 mm (20 in.) spherical radius presents the operator with some distance distortion, but objects in its view are easily seen. The "blind area viewer" consists of a modified fresnel lens that allows the driver to "look around the corner." Installation of three of these lenses on the front of each haulage truck is rec¬ommended for adequate blind area coverage. This system significantly increases an operator's field of view and allows viewing of objects within about 3 m (9.8 ft of the truck. Many open-pit mines are nor mounting on smaller vehicles a long whip with a flag and lamp or both. This increases vehicle visibility to haulage truck operators. The whip is permanently attached to the mine vehicle. It can also be magnetically attached to transient vehicles. The whip system. though, is inadequate for visibility in the critical rear and right front blind areas. Alternate Solutions All of these visibility aids as¬sume an attentive driver. In addi¬tion, areas such as the rear blinc, area are not covered. Based on the inadequacy of existing visibility systems, Anaconda made a com mitment to further the truck de¬tection technology. The best ap¬proach was considered to be ar active system. It would notify the haulage truck operator that an en¬croaching vehicle is present. Sev¬eral systems were considered, in¬cluding ultrasonics and elec¬tromagnetics. For the ultrasonic system, com mercial and in-house design were looked at. Designing an( building transducers with the spe cific beam shape to match the haulage truck blind spots re¬quired a major technological breakthrough. False alarms ap¬peared difficult to prevent en¬tirely. They were caused by pass¬ing, trailing, or leading vehicles a., well as nonthreatening objects. As a result of these problems, the ul¬trasonic technique was not pur sued. An alternative, an electro

Jan 7, 1982

By John O. Marsden

"This article is an attempt to capture a presentation given at the 2016 SME Mineral & Metallurgical Processing Division (MPD) Luncheon held on Feb. 24, 2016, in Phoenix, AZ. It was presented as a tongue-in-cheek, lighthearted view of several of the issues facing our industry, while identifying some of the challenges and opportunities available to new engineers entering the industry today.Disclaimer• What you are about to read includes personal preferences, biases and occasionally arbitrary opinions.• Some readers may have dissimilar opinions on the contents and/or the rank order of the lists.There are eight top ten lists offered in this article: (1) Industry realities (2) Things a metallurgical or mineral process engineering graduate should do (3) Books every metallurgist should have on their shelf (4) Things I wish I had known (5) Legends of metallurgy (posthumous, with highlights) (6) Things we’ve forgotten (7) Mineral processing innovations of the past 20 years and, finally, (8) The future? For some items, additional context or clarification is provided after the item, while for other items no further explanation is warranted and none is offered. Top 10 industry realities1. Metal price cycles.2. Bigger is better (except when it isn’t).3. Ore grades declining across the board of metals/commodities.4. Ores becoming more complex.5. Three-fold increase in capital costs between 2004 and 2015.6. Three-fold increase in operating costs between 2004 and 2015.7. Less capital availability/challenging financial markets.8. Environmental constraints increasing.9. Socio-political constraints increasing.10. The mine manager is always impossible to work with.As Table 1 shows, there was more than a three-fold increase in gold operating costs between 2004 and 2014. The increases for copper, iron ore and other commodities were similar."

Aug 1, 2016

By O. A. Bascur

The problem of setting the proper control objectives and/or having several objectives to be met in the implementation of grinding control strategies can be resolved. The design and implementation of a distributed control system for safe operation of a grinding circuit while maximizing profit is presented. An optimal recovery/throughput target for a desired grind is accomplished by advanced control strategies at the DCS level. A mill load constraint control technique provides stable operation with a substantial increase in throughput, while the desired grind index is maintained by an inferential grind control technique without using a particle size analyzer. The integration of crushing/grinding and flotation in the overall design was the key to the success of the project. This synergistic effect was obtained by implementing a computer -plant management system in the concentrator. The overall philosophy of keeping the implementation simple but not simpler was used.

Jan 1, 1989

By Roger K. McLimans

Sphalerite in the ores is multi-banded. Based on color and textures, bands in samples separated by a few kilometers may be correlated. Darkness of color is directly related to iron content. Isotopic and fluid inclusion data indicate that temperatures of ore deposition were 225°C-50°C. The agreement between these two sets of data suggests that chemical and isotopic equilibrium were established. The salt content and hydrogen and oxygen isotopic compositions are similar to present-day values of oil field brines suggesting a similar mode of origin. Ore transport and deposition are not adequately explained by either chloride or bisulfide complexing. Necessarily, other mechanisms were involved.

Jan 1, 1979

By Robert E. Charles

Much has been said about digital computer control of metal and mineral ore dressing processes, but little has been done. This pa- per discusses what practical use can be made today of a digital computer in an ore concentrator and how such application can be made successfully. A hypothetical, but commercially common, grinding and flotation circuit is presented in terms of analog measurements which can and are being made in existing plants and a centralized computer control system which is reasonable in terms of today's technology. Dangers and possible disadvantages of such an approach are discussed as well as estimated benefits. Possible future benefits are presented in terms of improved control technology. Development of new measuring devices is not considered as a criterion for computer benefits. The control systems described have been utilized successfully in existing ore dressing operations. However, the degree of success or failure of analog systems is generally left to the interpretation of management rather than absolute analysis. Many factors affect the economic operation of a mineral recovery circuit such as size of facility, flow sheet design, number of operating personnel, percent of recoverable mineral in the ore body, loss to tails, and haulage rates. In existing mills where little or no instrumentation has been used, it is extremely difficult to prove or disprove the advantage of analog control systems on one mill line versus its sisters due to the lack of standards and the lack of ability to separate final products by ton.

Jan 1, 1969

By H. R. Quina

Phosphate is one of the most important minerals in our world today. It contains the life-giving element of phosphorus, which is essential to the growth of every living cell in plant, animal, and man. This vital mineral is found in twenty-three states of the United States; however, for more than 70 years, Florida has led the nation in phosphate-production and now produces 70% of the requirements of this country. Since the early 1880% when rich phosphate deposits were accidentally discovered in a river-bed in Central Florida, the industry has developed into a multi-million-dollar operation. Phosphate mining began in Florida in 1887 with very crude methods and equipment. The original process was necessarily slow and tedious, resulting in total production of 3000 tons in 1888. Progress was made in improved mining operations, and by 1894. Florida had grabbed the lead as the nation?s largest phosphate-producing area, and is still in the top position.

Jan 1, 1962