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By W. Z. Rogers

U.S. feldspar output sold or used in 2004 was estimated to be 790 kt (871,000 st), valued at $43 million free-on-board plant. This was below 2003 and about the same volume as 2002. The strong housing market in the United States maintained demand for ceramic tiles, plumbing fixtures, and fiberglass insulation requiring feldspar and shipments of glass containers increased by about 4 percent. Imports of ceramic tiles and plumbing fixtures continue to increase, taking the place of U.S. produced goods, and the feldspar required to make them. Output included flotation concentrates, feldspar content in feldspar-silica mixtures, potash feldspar and aplite.

Jan 1, 2005

By E. Cho

Illinois No. 6 coals of IBC 101 and IBC 112 were treated in solution with sodium hypochlorite to remove their sulfur contents, especially organic sulfur. The lab experiments were conducted in two steps of leaching at room temperature and hydrolysis at 90oC. The removal of organic sulfur from IBC 101 was by 37.8% while that from IBC 112 was only 13.7% under their respective optimum conditions. This large difference in organic sulfur removal is considered to be due to difference in concentration of surface total acid group, 3.14 vs. 0.88 mmol/g of coal.

Jan 1, 2007

By M. E. Gershon

I would like to congratulate Professor Gershon on an idea that is obviously valuable and is certainly new to me. It has, however, to be further developed, in that one can get fallacious results by limiting oneself to positional weights. In the example problem, the positional weight of one block was 8.6 (the 8.0 value in the paper was incorrect) for 36 units in the cone, for a mean block value of 0.239. The positional weight of the second block was 4.4 for 15 units, for a mean block value of 0.293. Surely one would expect the second block to be rated higher. Additionally, the time value of money adjustment cannot be determined by depth, because the time that a block is mined is determined by the mining sequence, not depth. Figure 1 shows a slightly altered version of Professor Gershon’s pit. The overall value of the pit is the same, as are the total values under each of his blocks. The values in the right-hand cone have been reversed top to bottom, and the values in the rest of the pit adjusted to keep the central cone total unchanged. All values have been multiplied by 10. Figure 2 shows the sequence of mining, at three blocks per year, for Professor Gershon’s pit, and Fig. 3, the sequence for a pit under the other block. Table 1 shows the value and discounted value (157. ) of Professor Gershon’s pit, and Table 2 shows similar values for the second pit. It is apparent that the second pit schedule is more valuable than the first.

Jan 12, 1987

By G. Deschenes, W. Yen

Ammonium thiosulphate is a non-cyanide lixiviant for gold leaching. The major problem is the high reagent consumption. A combination of 0.3M (NH4)2S2O3, 0.03M CuSO4, 3M NH3 was used to leach a copper-bearing gold ore at pH 10.2 for 24 hours. 30 kg/t of thiosulphate was consumed. Oxygen and copper species were found to be responsible for thiosulphate decomposition. The thiosulphate consumption could be reduced to around 17 kg/t by adding chelating agent, reducing copper sulphate concentration to 0.001 M and replacing CuSO4 by NiSO4. The increase of pulp density might reduce the thiosulphate consumption to around 17 kg/t. By regulating the oxygen supply, the thiosulphate consumption could be reduced to 10 kg/t.

Jan 1, 2002

By Steve Kral

The Clinton administration’s policies toward the environment have the mining industry on the defensive. The president and US Secretary of the Interior Bruce Babbitt continue to bypass Congress in their efforts leave an environmental legacy when they leave office in a year. So the mining industry must take its case to the public. And the public seems willing to listen if the industry is willing to tell its story, according to US Rep. Chris Cannon (R-UT). Cannon was one of the keynote speakers at the105th meeting of the Northwest Mining Association, in Spokane, WA. The conference, held in early December, attracted about 2,400 people and more than 200 exhibitors

Jan 1, 2000

By R. L. Loofbourow

R. L. LOOFBOUROW 26.1-WATER FLOW, USE, EFFECTS, CONTROL Sec. 4 discusses ground water as a mineral resource. This section deals wits its control. 26.1.1-IMPORTANCE Flows of water have an important effect on the cost and progress of many deep excavations. The existence of water limits the methods which can be used in some and presents hazards in others. Lowering the water table may reduce the flow of springs and wells, with legal liability. Some mine water is used directly, some must he treated before discharge, and some contains dissolved solids which can be recovered profitably. Loss of life, property and production from flooding is grim, yet scores of mines have worked safely for generations under ground-water reservoirs, lakes and even the sea. The need for better control of mine water is measured by the severity of recent floodings, concern with the quality of the effluent, and direct and indirect costs of working wet ground. There are improvements in freezing in shaft sinking. pumps and their controls, treatment of mine water before it is pumped, bulkhead construction and certain efforts to reduce inflow. 26.1.2-PUMPING COST VS. COST OF WET WORK Direct operating and capital costs of pumping are more evident than indirect items, such as provision of extra standby power and maintenance facilities, The total of all these items is the cost of pumping water from an excavation. This is only a part of the extra cost of working wet as compared to dry ground. Less productive methods, less efficient equipment and more expensive explosives may have to he used in wet work. Wet rock plugs certain equipment. Maintenance is higher and labor less efficient. The cost of any means of keeping work drier should he weighed against the higher cost of working wet. The true difference in the cost of working wet ground, compared with dry, probably is known at only a few places (see checklist of cost items. Sec. 26.4.13). An extreme comparison of mining wet and dry ore is available from Ambrosia Lake, N.M. (Fig. 26-1). Between 1963 and 1967, a wet and a dry mine were worked by the same company under conditions otherwise comparable. Average operating cost at the wet mine, pumping 1,600 to 1,800 gpm. was $16.06 per ton of ore. The comparable figure for the dry mine was $7.50. Principal differences included the fact that the wet mine was worked from drainage levels below the, ore with rail haulage, the dry mine in the ore with off-track equipment loading and hauling to the shaft. In the wet mine, ore packed in chutes, cars and skips and froze in surface bins, stockpiles and trucks. Wet-mine costs included drilling drain holes, building and maintaining ditches and pumping water containing abrasive solids.

Jan 1, 1973

By E. M. Spokes

A.B. Rushton The work and resulting publications of the Committee on Underground Coal Mine Safety and The President's Commission on Coal were appropriate at the time of publication. The statistics cited in the publications appeared to be valid, and the actions proposed by the committee had merit. Although the actions proposed to achieve further improvements in safety may have been worthy of repeating, to associate statistics (Table 1) that are seven to eight years old with company names is bad. Statistics are readily available from the Mine Safety and Health Administration (MSHA) and are usually within three months of being up to date. A review of the most recent Coal Controlling Co. Report will reveal significant changes in the rankings. The more recent statistics should have been cited, or at least compared with those used in the article. Westmoreland Coal Co. is listed as having a 21.1 disabling injury rate for the period (1/78-12/80). The disabling injury rate for the Company for the year ending 1985 was 7.4 for the underground mines and 6.25 for the total facilities. Through March 1986, the disabling rate for the underground mines was 2.86. The management and employees of Westmoreland Coal Co. are committed to safety. The improvements achieved over the past five years attest to that commitment. We are justifiably proud of the achievement and dislike being misrepresented as in the April 1986 article. Reply by E.M. Spokes I regret that the lapse of time since the original work gives a picture of safety practice that is no longer true today. That Westmoreland has reduced its disabling injury rate by 65% to 7.4 in 1985 is most commendable, and I congratulate you for this accomplishment. It is typical of the progress sought by the National Academy of Science and National Research Council when they funded the original study and published "Toward Safer Underground Coal Mines" in 1982. If a significant number of companies do as well as Westmoreland, the report will have served its purpose. Since the paper was primarily a condensation of the original report, it would not have been appropriate to seek access to later statistics. The purpose in seeking its publication at the time of presentation was to reach those who might have missed the original report. The fact that publication was delayed has not voided that purpose and may have reminded some who were aware of the original that its recommendations still apply to improvement of underground coal mine safety.

Jan 6, 1986

By I. J. Wu

China’s land area, comparable in size to United States or Canada, contains diverse geological environments and mineral resource potential. The diversity in geological environments is such that the potential for developing many world-class mineral deposits in China is good. However, China’s mining sector was not open to foreign investment until the1990s. The long-term prospect for Chinese resource development is attractive because of China’s enormous population and cumulative demand for minerals. Approximately 33 foreign mineral companies, including 11 major internationals, are to various degrees active in China. Chinese mining laws and regulations pertaining to joint ventures with foreign companies are, from the international investment prospective, evolving slowly, but positively. This positive trend is continuing under the current government reform process, which is moving China towards a freer market economy. Although improving the enforcement of relevant laws and regulations is an ongoing process, the environment for mineral investment and joint ventures is increasingly more accommodating to foreign companies.

Jan 1, 2000

By A. Adu-Acheampong

Photogrammetry and laser scanning has been employed at a number of Newmont mine sites to mitigate risks associated with conventional structural mapping, determining the geometry of voids from old underground workings, and generating topography in areas of slope instability. Laser scanning has also been used to evaluate as-built pit slope configurations with respect to design assumptions, operational practices, and rock fall potential. Recently, remote sensing applications carried on an unmanned aerial vehicle (UAV) were used to generate base topography at some Newmont sites. UAV are generally more convenient and less expensive and can be utilized in areas where cloud cover prevents manned aerial photography missions. This paper discusses these applications, and provides commentary on their benefits and limitations based on recent experience.

Feb 27, 2013

By R. D. Lawrence

Suggestions have been made that the appraisal of mining assets using discounted cash flow techniques should be based solely on proven and probable reserves in reliance upon the widespread international recognition of uniform resource definitions. Following a review of general accepted valuation principles, a survey of the literature and, most importantly, a review of real transactions in the open market, it is clear that valuators should not be constrained by the growing acceptance of modern mineral resource codes. On the contrary, valuation practitioners should be encouraged to examine all classes of mineralization and, after making due allowance for risk, to utilize all mineral resources as a basis for determining fair market value.

Jan 1, 2000

By Xiaoting Li, Richard Adasiak, Benjamin Mirabile

Pumpable J-Crib stopping walls and Jennmar high-strength (HS) stopping panel walls are widely used for resisting high-ventilation air pressures and roof support in underground mines due to their installation efficiency, convergence allowance, and better performance than traditional concrete block stopping walls. Based on the different entry dimensions and required maximum ventilation air pressures of up to 36-in. water gauge, 24-, 27-, 30-, and 36-in.-diameter pumpable J-Crib stopping walls, or 18- to 30-in. thick Jennmar HS stopping panel walls can be designed, and their support capacities and convergence allowances are evaluated for better roof control. Pumpable J-Crib stopping walls consist of 0.187-in.-diameter steel wire reinforced, JCrib material-filled bags, and non-wire-reinforced filler bags in between. Jennmar HS stopping panel walls consist of two, 20-gauge (0.04-in.-thick), galvanized, cold-formed steel panels with J-Seal materials pumped in between. Based on the fundamental structural design principles and specifications of ACI 318-19(22), the compression and flexural strength, and shear resistance of the walls can be checked to be compliant with the codes and specifications following the load and resistance factor design (LRFD) method. Specifically, the 0.187- in.-diameter steel wires in the pumpable J-Crib walls and 20-gauge steel panels in the HS stopping walls are integral parts of the walls and are considered to effectively confine the J-Crib or J-Seal materials. These steel elements play a significant role in reinforcing and improving the strength or support capacity of the stopping walls from a structural design perspective. Because of the high ductility of low-density J-Crib/J-Seal materials and steel elements, these walls are good at accommodating or absorbing the roof convergence (≥5% entry height), which cannot be matched by a traditional concrete block stopping wall (Figure 1). Based on the successful design and application of these stopping walls in different mines for improving roof stability and avoiding the air leakage, the authors have formulated the design methodology and verified independently by the finite element analysis (FEA) simulation technique. This design methodology combines the fundamental structural design principles with specific wall dimensions and material properties, facilitating mine engineers and government agencies to understand the in-depth working mechanism of these stopping walls.

Jul 1, 2023

By C. L. Van Dover

Organisms living at hydrothermal vents are adapted to catastrophic disturbances in their environment caused by processes such as tectonic activity and mineralization that shift the locus of fluid flux and volcanic eruptions that pave over active systems and reset the hydrothermal cycle. The scientific community appreciates this risk of natural, local loss of species, genetic, and habitat diversity. The risks of more profound loss of diversity and ecosystem function and health as a consequence of additive commercial activities in hydrothermal systems are unknown, and are not the same across all deep-sea hydrothermal systems. Vent communities differ from one ocean basin to another, as do the geological settings and geochemical dynamics of vent systems. Communities on the East Pacific Rise represent one end-member in the catalog of hydrothermal vent communities. In these systems, the life cycle of a hydrothermal field is on approximately the same time scale as the lifespan of the species that live there. From studies of the 1991 and subsequent eruptions at 9N on the East Pacific Rise, we understand the rapidity with which new vents are colonized when nearby brood stocks are available to repopulate the system. Almost instantaneously, microbial biofilms and mats form, followed quickly by invasion of mobile opportunistic organisms (especially crabs, copepods). In a matter of a few months, a predictable succession of sessile organisms recruits, grows, and reproduces. Within two to three years, the system returns to levels of species diversity that begin to match those of the pre-eruption condition. Vents on the Mid-Atlantic Ridge (MAR) represent a different end-member, with catastrophic disturbance rare relative to the life span of the organisms that make up the bulk of the biomass. We have no experience with an eruptive event or other major transformation of venting activity on the MAR and thus have no knowledge or insight regarding the time it would take for the biological diversity to return to pre-cataclysmic levels.

Jan 1, 2008

By J. M. Manka

American mining companies operate many drum hoists that hoist from various depths with varying payloads. This paper will review the procedure of selecting optimum wire rope constructions for these existing hoisting installations. Selection for proposed installations along with recommended hoisting parameters will also be presented. To achieve this optimum rope performance, preventative and corrective maintenance procedures will be reviewed along with examples of rope problems and their causes.

Jan 1, 1992

By Rafael C. Castro, John Overton, Gregg Sherry, David A. Sutter

This paper presents an innovative ground support solution developed to construct a tunnel cross-passage for the MUNI Metro Turnback (MMT) Project. A “soft center” jet grouting approach was designed to provide solid ground support while maintaining a soft center to allow for hand-mining of a 2.44 m (8 ft.) wide, 3.66 m (12 ft.) tall and 4.6 m (15 ft.) long cross-passage through soft Bay Mud. Prohibitive costs and schedule impacts associated with mining under compressed air (at the time being used for main tunnel construction) were the catalysts to search for alternative methods for cross-passage construction. Limited surface disruption, relatively low costs, ease of subsequent excavation, nominal schedule impacts and proven local success of jet grouting were key factors in selecting and designing this method of ground support.

Jan 1, 1997

By Jean-Michel Rendu

On April 30, 2003, representatives of the Society for Mining, Metallurgy and Exploration, Inc.(SME) met with the staff of the Division of Corporation Finance of the U.S. Securities and Exchange Commission (SEC). The meeting was held to discuss issues related to the estimation and publication of mineral resources and ore reserves. It took place in the Washington, D.C. offices of the SEC. SEC staff members included Roger Schwall, assistant director, Division of Corporation Finance; Jill Davis, senior accountant; Roger Baer, senior mining engineer; Carl Chavez, chief mining engineer; Ron Winfrey, senior petroleum engineer; and John Murphy, senior petroleum engineer. SME committee members included JM Rendu, independent consultant and chairman of the SME Committee on Resources and Reserves; Ian Douglas, manager of deposit modeling and reserve estimation with Newmont Mining; Art Graham, director and mining engineer with Deutsche Bank Trust Company Americas; Larry Smith, chief geologist with AMEC Mining and Metals Consulting; and George MacDonald, vice president of exploration with Freeport-McMoRan Copper and Gold.

Jan 1, 2003

By William G. Doepken

With most of the mining industry emerging from the deepest business recession in 50 years, primary attention must be given to surviving in a business climate where dominant foreign competition, depressed prices, and potential overcapacity hang heavy over much of the industry. While already shackled with regulatory constraints, restrictive work rules, and high labor costs, mine operators are faced with the difficult task of reducing costs and improving productivity while operating at less than full capacity. To counter these nearly over-whelming factors, the mining industry must continue at the national level to seek regulatory relief and a rational policy toward foreign competition from government-controlled mines. In addition, dialogue with labor organizations must continue to minimize the impact of labor costs, cost escalators, and antiquated work practices. Although national and international actions have a tremendous impact on the future of domestic mining operations, local actions by mine operators to dramatically improve mining productivity will strengthen the industry's competitive stance. Before any substantial progress can be made, however, mine operators must recognize and define areas that depress productivity and establish goals and measures for improvement. Once problem areas are defined, a combination of technological and motivational concepts can be applied to improve productivity. Timing of Improvements While there is an immediate need for productivity improvements, only certain concepts offer near-term improvement potential while others must, of necessity, fit into a mid-range or long-range time frame. Near-term solutions (immediate to one year) likely will involve motivational concepts - work incentives and training - coupled with available technological concepts that require little capitalized development or site testing. Mid-range solutions (one to three years), by contrast, will include technological improvements in mining equipment, techniques, and systems automation. These concepts require a longer period of capitalized development and site testing before use. Long-range solutions (three years or more), which include adoption of new mining methods and computerized control systems, will appear only after prolonged research and capitalized development programs. Motivational Improvements Developing motivational con-

Jan 11, 1983

By William Gleason

At 6,898 ft below surface, the historic No. 9 shaft at Resolution Copper near Superior, AZ is now the second deepest single lift mine shaft in the United States and connects to the deepest single lift mine shaft in the U.S., Resolution Copper’s No. 10 Shaft (6,989 feet). The shafts serve as ventilation and access for future underground development of what could one day become one of the most significant copper mines in the United States. It is from the base of No. 9 and No. 10 shafts that hundreds of employees of Resolution Copper, a joint venture of Rio Tinto and BHP, hope will soon be given the go ahead to begin driving lateral tunnels to reach a copper deposit that is estimated to contain 28 Mt or 40 billion pounds of copper. Copper was recently added to the U.S. Geological Survey’s (UGGS) critical minerals list, in large part because of increasing demand. A study by S&P Global Energy & Market Intelligence “Copper in the age of AI: Challenges of electrification” released on Jan. 8, 2025, “identifies a transformative trajectory for copper demand, projecting a surge from 28 Mt (31 million st) in 2025 to 42 Mt (46.3 million st) by 2040 – a 50 percent increase that underscores the metal's pivotal role in multiple technological and economic domains.” The surge in demand is driven in large part by the global energy transition, electrification of vehicles, growth of artificial intelligence and data centers, and most recently robotics. Meanwhile, geopolitical tensions have increased the focus on the need for the United States to secure more of its own mineral supply chain. S&P Global’s report is one of many warnings that while copper demand has accelerated rapidly, future supply is being held back. Resolution Copper stands out as one example of a known mineral deposit remaining locked in the United States’ complex and lengthy permitting slog.

Feb 1, 2026

By Albin E. Anderson

The PSM System has been available to the mining industry for nine years. During this time, many of the more than 160 Systems sold have been put to practical use and have provided the owners a handsome return on investment. In this paper, the author will briefly discuss how the System works and how it can be put to use in automatic grinding circuit control. Throughout, detailed consideration will be given to the many factors that can significantly influence how successful a specific application is.

Jan 1, 1979

By L. J. Lindsay

Kaiser Resources Ltd. operates a coal mining complex in Southeastern British Columbia. A large surface mine, a conventional underground mine, and an innovative hydraulic underground mine are presently in operation. The products of these mines are fed to the Elkview plant. This coal has to be prepared to 9. 5% ash and 6'o total moisture for export from the port of Roberts Bank near Vancouver, British Columbia to Japan at a rate of 4. 5 Mltpy. The moisture requirement for the coal product was recently increased to 8. 0% total moisture. The entire operation has been described in various publications (1), (2), (3). Details of the venture will not be repeated in this paper. In this paper we hope to describe the modifications made to the original coal preparation plant in order to satisfy market requirements for quality and quantity of coal.

Jan 1, 1974

By E. Knell

COM Energy, Inc., a subsidiary of Occidental Petroleum Corporation, has constructed a 1.6 million hectoliter-per-year COM plant in Jacksonville, Florida. COM will be distributed to customers in the region as a substitute for fuel oil presently burned in boilers and kilns. As the market for COM grows, COM Energy, Inc. expects to build additional units both in this country and overseas. This paper addresses the overall status and technical aspects of the project, focusing on the facilities for COM production and utilization.

Jan 1, 1982