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By Robert F. Brindisi

There are approximately thirty to forty operating mills in the United States which are currently producing uranium yellow cake. This figure includes a significant number of in situ and by-product operations however the conventional acid leach flowsheet depicted in Figure 1 is the most common process used by domes- tic yellow cake producers. Ground ore is leached with sulphuric acid and the solids are separated from the pregnant liquor and washed in a series of counter- current decantation thickeners. After clarification of the pregnant liquor, uranium is recovered from the solvent extraction/stripping circuit by the addition of ammonia with precipitation of ammonium diuranate, or simply yellow cake. The yellow cake precipitate is then thickened in a conventional thickener before re- porting to the dewatering/washing unit operation. De- watered solids subsequently report to thermal drying, and clarified liquor from the dewatering/washing step is recycled to the yellow cake thickener. The yellow cake dewatering/washing unit operation is generally accomplished using either a solid bowl centrifuge or a rotary vacuum drum filter. In most cases the underflow from the yellow cake thickener is pumped to the dewatering/washing unit operation at approximately fifteen to twenty percent solids. For the purpose of this discussion ammonium diuranate, the product of ammonia precipitation from a conventional acid-leach uranium mill flow sheet, as discussed earlier, will be considered. With only slight adjustment this discussion will be equally applicable to sodium diuranate or uranium perioxide precipitates and to either in situ or by-product operations where such precipitates are generated. Some of the domestic uranium mills which have selected solid bowl centrifuges instead of vacuum drum filters for the dewatering/washing unit operations are listed in Figure 2. Why have these uranium mills, as well as others not listed, chosen to use the solid bowl centrifuge for this particular application? It is simply a matter of performance, reliability and economics. In the remainder of this paper the performance, initial cost, installation cost, maintenance and power consumption of both the solid bowl centrifuge and the rotary vacuum drum filter will be com- pared. In order to provide a consistent basis for comparison the appropriate sized (centrifuge or filter) unit for the dewatering/washing of 400 to 500 pounds per hour of yellow cake solids will be considered. Such a flow will usually be generated by a typical 3,000 ton per day (acid-leach) uranium mill.

Jan 1, 1980

By Paul Kunze

For some of us, the most disagreeable part of being the blaster- in - charge is doing the required paperwork. Cost coding on time cards, drilling reports, magazine inventory logs, and blast records all eat into our time. When all goes well, which I suppose is 98% of the time, the blast records are submitted and filed, probably never to be seen again. Sometimes a progressive operation will use the information documented in the blast reports to evaluate blasting effectiveness and improve results. When the report is consistently used in this fashion, costs can be reduced and other efficiencies will be realized. A blast report in times past was a simple form that mainly was used to keep track of the drill footage and of the powder used in the shot. However, as the population and consequences of careless blasting increase, multiple levels of blast documentation are now being required nearly everywhere, during all phases of the drill and blast process. We are now compelled to create preliminary blast designs prior to commencing work. We are required to submit pre-blast plans before each shot, and we need to generate post-blast reports that document the details and results of each shot.

Jan 1, 2004

By Paul Kunze

We have been told many times by legal folks and insurance types about the importance of producing accurate blast reports should you ever get dragged into court. In that venue the investigators will look at the information regarding product type and quantity, it’s distribution among the holes, and delay information in order to arrive at some judgement regarding vibrations or other blast induced phenomena

Jan 1, 2003

By AIME AIME

DURING my senior year at college a professor said to his class that a student who failed to obtain a passing grade in that certain subject could not graduate with his class and that his diploma would be withheld until the failure had been removed. In that way for four years a diploma had been made to appear to us as the objective in attending college. We grew up to think that a diploma was the means of providing employment; consequently, a diploma could not be jeopardized and, heeding the professor's remarks, we resolved to put forth special efforts and make good. During one of our class periods this same professor digressed briefly from his prepared lecture in metallurgy and advised the boys to join a national technical society. He spoke with earnestness and sincerity. After class we students discussed those remarks. We concluded that the professor had not convinced us. We were already members of technical societies at school and saw no need of joining another. In fact, even up to that moment a society had never indicated to any of us that joining it had any relation to landing a job, and we were fully aware that joining another society meant paying out more money, for fees and dues, which money we then needed to buy food, clothes, and perhaps a new slide rule. Furthermore, we knew that joining a society was not part of the curriculum and, therefore, the diploma could not be withheld if we did not follow the advice. Our conclusion was that we would not join but would concentrate on our work that assured getting our diplomas.

Jan 1, 1936

"1.0 DESCRIPTIONThis work consists of furnishing all necessary labor, equipment, and materials to install prefabricated vertical (wick) drains in the ground in accordance with the Plans and as specified herein.2.0 REFERENCED CODES AND STANDARDSASTM D4716-08 Standard Test Method for Determining the (In-plane) Flow Rate per Unit Width and Hydraulic Transmissivity of a Geosynthetic Using a Constant HeadASTM D4632-08 Standard Test Method for Grab Breaking Load and Elongation of GeotextilesASTM D4533-11 Standard Test Method for Trapezoid Tearing Strength of GeotextilesASTM D4491-99a Standard Test Methods for Water Permeability of Geotextiles by Permittivity (2009)ASTM D4751-04 Standard Test Method for Determining Apparent Opening Size (A.O.S.) of a GeotextileASTM 6918-09 Standard Test Method for Testing Vertical Strip Drains in the Crimped Condition3.0 QUALIFICATIONSThe Contractor shall have successfully completed a minimum of five wick drain installation projects in similar ground conditions, and installed not less than 5,000,000 linear feet (1,525,000 linear m) of wick drain in the past five years. The Contractor shall have a minimum of five continuous years of wick drain installation experience."

Jan 1, 2014

By Brian McGlynn

There are many factors that can result in a site characterization being limited. For example, a client may undervalue the importance of a good geotechnical report, or an owner may feel that it would take too much time to perform an appropriate investigation among other reasons. For this project, neither was the case. The challenge was that the construction sequence of work required wick drains to accelerate the settlement of soil that had yet to be placed, resulting in the need to create a wick drain bid package based on unknown settlement parameters. This wick drain project took place in Long Beach, California, at the Long Beach Middle Harbor Re- development. For much of the past decade, the Port of Long Beach undertook a $1.5 billion redevelopment of two outdated terminals to create the Long Beach Container Terminal (LBCT). To achieve this goal, the existing terminals were demolished and the slip that serviced one of the older terminals was designed to be infilled to create the new area that would allow for the LBCT to manage 3.3 million TEUS (a commonly used freight term meaning twenty-foot equivalent unit) of cargo each year. Ultimately, the construction of the LBCT would be performed under multiple contracts to allow the new terminal to begin operation in a phased approach. Menard performed the wick drain installation under two out of three contracts, and this case history focuses on the challenges anticipated and faced under the second of these awarded contracts.

May 1, 2023

By J Morgan

Regular monitoring of surface deformation over mine sites is important for providing updated information to managers regarding geotechnical risks related to ground instabilities. This is particularly true in cases where unexpected or accelerating movement patterns are observed, as these trends may have implications related to worker safety within active mining environments, as well as continuity of ongoing operations. InSAR is an active remote sensing technique that uses radar satellite imagery to precisely measure ground movement. This technology has started to become a standard tool for monitoring surface stability in many different sectors, including underground and open pit/cut mining applications. In recent years the launch of satellites that collect radar imagery on a more frequent basis, coupled with advances in InSAR processing techniques, has improved both the extent to which movement patterns typical of mining operations can be characterized and the temporal scale on which results can be reported to geotechnical departments. As a result of these developments, InSAR monitoring can now better meet the operational needs of mine sites. An overview of the more recently launched satellites that have a particular relevance to the monitoring of mines is provided, along with an explanation of the InSAR tools that are the most valuable to mine managers and geotechnical engineers. First, broad differences between high resolution X-band imagery and low resolution (but freely available) Sentinel imagery are discussed. Second, the various InSAR tools and their particular applications for different types of mine sites and operations are covered, which include fast delivery deformation maps for short-term reporting, multi-interferometric algorithms for longer-term analyses and rapid movement tracking (RMT) for emergency monitoring or high-risk situations. The ability of the technology to resolve 2D and 3D movement is also touched upon. Practical examples of InSAR application over a variety of mine sites will be presented, as well as surrounding hazards including landslides, to illustrate how InSAR can help provide geotechnical engineers with a picture of surface stability over the full mine site and surrounding areas to help manage risk. CITATION:Morgan, J, 2018. Wide area mapping of ground instabilities from space: InSAR for geotechnical risk assessment and hazard monitoring, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 375–382 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By J. B. Platt

Many utility fuel choices 1990-95 defied expectations, with utility decisions and coal market developments ever more closely linked. The Central Appalachian coal boom never occurred; clean-enough coal was developed in the hard-hit Midwest; Colorado-Utah coal surged; Pittsburgh seam production strengthened; utilities embraced Powder River Basin coal; and emission allowance prices collapsed. Competition drove productivity gains, but the future is not a simple repeat. Phase 2 brings fewer viable compliance options. Mega-railroad pricing has become a key risk factor --will this be countermanded by merging utilities and power market competition? Revenue losses from vintage contracts are problematic. Uncertainty also plagues natural gas, in spite of unanimity across major forecasts, since recent experience has been so heavily influenced by the gas bubble.

Jan 1, 1997

By J. B. Platt

Many utility fuel choices 1990-95 defied expectations, with utility decisions and coal market developments ever more closely linked. The Central Appalachian coal boom never occurred; clean-enough coal was developed in the hard-hit Midwest; Colorado-Utah coal surged; Pittsburgh seam production strengthened; utilities embraced Powder River Basin coal; and emission allowance prices collapsed. Competition drove productivity gains, but the future is not a simple repeat. Phase 2 brings fewer viable compliance options. Mega-railroad pricing has become a key risk factor -- will this be countermanded by merging utilities and power market competition? Revenue losses from vintage contracts are problematic. Uncertainty also plagues natural gas, in spite of unanimity across major forecasts, since recent experience has been so heavily influenced by the gas bubble.

Feb 24, 1997

By Sherwin F. Kelly

NEW trend in geophysics has been uncovered in these depression years, made evident through the thinning cloak of commercial activity, which, in better times, would have completely obscured it. I refer to the increasing use of these methods for geological investigations by federal and state geological surveys. This is a trend that has been gathering momentum not alone in the United States, but abroad as well. Thus, in Poland, the Geological Survey has been playing an increasing role in geophysical work since 1927, and now has- its own geophysical department. The government petroleum producing organization of Argentina has its Geophysical Commission; Brasil boasts a completely equipped geophysical department in its Mineral Production Service; the government of Chile has contracted with commercial companies for geophysical surveys; Peru is planning an intensive program of geophysical prospecting in its petroliferous regions; and Canada has, for several years, cooperated with

Jan 1, 1935

By Robert G. Ditchburn, Albert Zondervan, Akira Usui, Hiroshi Shibasaki, Hajime Hishida, Ian J. Graham

Earlier reconnaissance geological survey and recent mineral exploration by the Geological Survey of Japan (now part of AIST), Metal Mining Agency of Japan (now part of JOGMEC) have revealed that hydrogenetic ferromanganese crusts are widespread over rock outcrops of the floor of the NW Pacific Ocean, south and east of the Japanese Islands, despite vigorous tectonic activity, such as subduction and backarc spreading. Deposition of ferromanganese oxides has occurred since at least the mid-Paleogene over the Philippine Sea Plate region and nearby.

By J. Brune

The need for reliable and adaptable underground mine communications has become a focal point for both the safety and logistics of a mining operation. New mine communication technology aims to connect personnel, equipment, and data together while setting up a network that can be utilized during normal operations and also in an emergency event. The Mine Improvement and New Emergency Response Act of 2006 (also known as the MINER Act) requires mine operators to establish post-accident, two-way communication between underground and surface personnel and electronic tracking for all mine personnel. Communications systems must be designed such that they can survive major mine accidents, including explosions, fires, inundations and ground falls. Typical, wire-bound communication technologies are vulnerable because wires are often destroyed in such accidents. Wireless technologies that work well on the surface, such as cellular telephone networks; have limited applicability underground because the wireless signals do not propagate through rock.

Feb 23, 2014

By Art Frye, Lee Pratt, Gaichang Zhao, Greg Newman

This paper will discuss the Wight Pit wall slash at the Mount Polley open-pit copper-gold mine that scavenged a high grade block of ore from two double-benches of the pit wall. The Wight Pit orebody, discovered in 2003, is located in the Northeast of the property with the southeast pit wall approximately 50m (165ft) from the edge of Polley Lake. In early 2009, the Wight Pit was nearing completion while an estimated 150,000 tonnes (165,000 tons) of ore averaging a grade of 1.4% copper remained just inside the southeast pit wall. The ore block started 24m (78ft) above the pit floor and extended up another 48m (157ft) with a 70o plane defining the back of the block.

Jan 1, 2011

By AIME AIME

WILBER JUDSON is one of that fairly large group of mining engineers that graduated at an Eastern college, worked his way up in various jobs in the West and in the Latin-American countries, and finally came to New York as an administrative officer of a large mining company. Since coming to New York he has been a loyal friend and counselor of the A.I.M.E., and is now serving a second term as one of its Directors, his first term covering the period 1935-1938. Mr. Judson was born in the capital city of Michigan on July 26, 1880. Probably it was his roving spirit rather than professorial urging that was responsible for the fact that four colleges were responsible for his education: Northwestern, University of Michigan, Harvard (S.B., 1901), and the Michigan College of Mines (graduate study). In his first ten years of professional work he might have been found serving as mine foreman at Catamarca in the Argentine, as superintendent of the Inter Ocean mine at Sunshine, Colo.. as foreman for the Cerro Prieto, Magdalena, Sonora, as superintendent of the Hudson Iron Co. in New York, or as manager of the Dolores mine in Chihuahua for the Mines Co. of America, or in Spain, or in Panama.

Jan 1, 1942

By Steve Kral

Conference themes are usually chosen by organizers to reflect the current state of the industry. The Colorado Section MPD came up with what may be the most appropriate theme of a mining conference during the last few years. The local SME MPD section’s theme of its 56th annual conference was “The Wild, Wild World of Mining.” The current boom can be felt in all aspects of the industry, including exploration, mining, processing, sustainability, and economic and political issues. Each of the 25 speakers at the conference, held in Colorado Springs, CO, touched on how the boom has impacted each of those aspects. The meeting attracted about 110 people from around the world.

Jan 1, 2006

By E. G. SINCLAIR

DRILLING wildcat wells in Wyoming differs a little from methods used in any other field. Here it is always advisable to start the hole as large as is convenient in order to carry each string of pipe as far as possible, so that drilling can be continued a thousand feet deeper if necessary, as there is always sand a few hundred feet ahead that really ought to be tested. This plan may seem ambitious, but if it is adhered to, it will save a great deal of trouble before the well is completed. In making the location, one representative from the operating department and one from the geological department should work together, so that the well may be in the best possible place for obtaining oil and the most feasible place to drill for the operating department. In Wyoming nearly all wells are drilled with standard tools, as with them a better log can be kept and better time made in completing the hole. The shales of Wyoming are very hard and do not mix well in a wet hole. The shale cuts into large pieces, too large to be circulated out of the hole, and forms a mat on the rotary which soon cuts off circulation. Then if this mat cannot be jarred from the bit, the drilling string has to be pulled and the mat cut off from the bit with a pick or an axe. I have seen standard tools come out of a wet hole with 10 to 16 in. of mat on the bottom of the bit. Rotary tools have drilled wells satisfactorily in the Big Muddy field and at Billy Creek, but in the other fields the wells have been drilled much more economically with cable tools.

Jan 1, 1926

By D B. Donato

Gold mining cyanide-bearing solutions can pose a risk, cause significant wildlife deaths and adverse public relations and result in non-compliance with regulatory conditions. The International Cyanide Management Code for the Manufacture, Transport and Use of Cyanide in the Production of Gold (the Code) was developed as a voluntary code to encourage industry-wide improvements in managing cyanide responsibly. The Code requires design and implementation of robust monitoring programs for compliance under the following standards of practice: 4.1, 4.4 and 4.9. A robust monitoring regime can be complicated as each processing and tailing system is different. The following systems are commonly used in Australia: carbon-in-leach (CIL); carbon-in-pulp (CIP); heap leach process ponds; tailing waste disposal systems; peripheral discharge, central discharge and in-pit disposal. Some terrestrial wildlife can be denied access by fencing tailing storage facilities (TSFs) or other physical barriers, therefore limiting wildlife interaction with cyanide-bearing tailing and solutions to mainly birds and bats. While wildlife monitoring programs for processing and TSFs contain similar core attributes, it is necessary to adapt monitoring to take into account the site-specific features of each system. These core attributes are discussed in this paper, with reference made to cyanide concentration and associated methodologies. The issue is considerably complicated if tailing solutions are deemed or discovered to be toxic to wildlife. Essentially cyanides are required to be measured to gain an understanding of the concentrations to which wildlife may be exposed. This usually equates to measuring the cyanide concentration of solutions entering and leaving a tailing system. To assess the risk to wildlife presented by tailing and heap leach systems it is necessary to monitor both the hazard (cyanide concentrations) and the exposure (live wildlife species, presence and interaction). These tasks need not be arduous and a system of simple frequent monitoring has been developed and implemented for Code compliance. The wildlife monitoring developed by Donato Environmental Services (DES) and used at mining operations departs from the industry norm. It documents observer effort, live wildlife presence, habitat and behaviour in a tailing system, as well as deaths and carcasses. A greater understanding of wildlife cyanide toxicosis associated with this monitoring approach will enable mining companies to adopt a proactive approach to significantly reduce, or preferably eliminate, the impact on wildlife and assist in gaining Code compliance.

Jan 1, 2007

By Richard Howie

Avian Diversity ?? Pre-mining ?? 110 - 125 species would have occurred ?? Dominated by forest species ?? Wetland productivity unknown ?? Post mining ?? 192 documented ?? Forested species in reduced numbers ?? Increase in wetland species ?? Increase in open country/grassland species

May 1, 2008

By AIME AIME

THE CHAIRMAN of the fast growing Petroleum Division is not only a graduate of the University of California, but a third generation native son. After a few years spent in hard-rock geology, his professional efforts were transferred to the sedimentaries and to petroleum investigations, as a consulting geologist. For ten years these investigations covered the Rocky Mountain, Oklahoma, Texas, and eastern districts. After the war he returned to Casper, Wyo., as chief geologist for the Consolidated Royalty Oil and Western Exploration Companies. This employment afforded him the opportunity to study particularly the economic relationship between the lessor-lessee interests in development and production, a somewhat unusual type of petroleum specialization.

Jan 1, 1939

THE great development of the mines and metallurgical works of this country during the last few years, accompanied as it has been by the investment of enormous sums of money in purchasing lands, and in the erection of improvements, requires that advantage should be taken of the accumulated knowledge of engineers, superintendents, and' others, in mastering &he problems which are constantly presenting themselves for our action. Among those may be mentioned the consideration of more economical systems of mining in our coal and metal-liferous mines, improved methods of transportation above and below ground, unwatering and ventilating mines, the mechanical preparation of coal and other minerals, the various metallurgical processes, and, in fact, every question tending to the attainment of two great objects : 1st. The more economical production of the useful minerals and metals. 2d. The greater safety and welfare of those employed in these industries. In European countries, where the arts of mining and metallurgy have long been the subject of the most careful study, no means have been found so effectual in attaining the end above proposed as the free interchange of experience among those actually engaged in these industries, and this object has been accomplished, mainly, through the medium of institutes, associations or societies, composed of those engaged in these occupations, and by the periodical publication of essays or papers, communicated to such societies by their members. I t must be evident to all practical men that the interchange of the varied experience of those engaged in such occupation in this country could not fail to advance very materially the desired objects; it is, therefore, proposed to establish an American Institute of Mining Engineers, which will hold its meetings periodically in the great mining and metallurgical centers, where works of interest, such as mines, machine shops, furnaces, and other metallurgical works, can be inspected, and the members exchange their views, and consult for mutual advantage upon the difficulties encountered by each; these transactions or proceedings, when published, would form a most valuable and greatly-needed addition to our professional literature. I t is proposed that a meeting of those sympathizing with the object above mentioned shall be called for the purpose of organizing such an association, the place and time of meeting being Wilkes-Barre, Pa., and the month of April or May. Communications indicating the opinion and wishes of all, both as to these points, and also as to the organization and objects of the Institute, will be gladly received by any of the undersigned, and a notice of the date of meeting, which will be arranged to suit the greater number, will be duly communicated. Any