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New technology makes Mining Safer By Mike Woof, World Mining Equipment
Many hazards on modern mine sites can be minimised by adopting new technology. Heavy equipment, given the potential blind spots for the operator on many, if not most, items of plant. But CCTV and radar systems for instance can minimise collision risks. Similarly, good site communications can ensure that personnel are alerted to hazards and informed of movements on site. Customers can also fit devices that reduce the risks of sudden machine fires. more...
SPCC estima que posible fusión con Minera México sería buena
Empresa espera producir este año unos 850 millones de libras de cobre frente a los 800 millones del 2003, debido a las mejores leyes en sus minas de Cuajone y Toquepala.
La minera Southern Peru Copper Corporation dijo que una fusión con una firma de propiedad de su mayor accionista, el Grupo México, le traería "grandes beneficios", idea contraria a la de sus trabajadores que amenazan con iniciar una huelga.
Los directivos de Southern Perú y los líderes de los obreros de sus dos minas, Toquepala y Cuajone, vienen negociando para evitar la medida de fuerza anunciada para el 31 de agosto contra la fusión y en demanda de mejores sueldos.
"Esperamos que no se concrete (la huelga). Creemos que estamos más cerca de un acuerdo (con los trabajadores)", dijo el domingo un portavoz de la empresa a Reuters.
En un comunicado publicado en la prensa local, Southern Perú afirmó que aún evalúa la propuesta del Grupo México - el tercer mayor productor mundial de cobre - de transferirle las acciones de su subsidiaria Minera México, pero consideró que el plan mejoraría sus resultados.
"También queremos aclarar que la Sucursal (Southern) no se hará cargos de las deudas de Minera México si se produce la venta de las acciones. Minera México seguirá pagando sus deudas al igual que la Sucursal pagará las suyas", afirmó la firma.
La semana pasada el vocero sindical, Elmer Gallegos, afirmó que las minas Cananea y La Caridad, de Minera México, tienen una deuda de 800 millones de dólares. "Southern es una empresa rentable. ¿Por qué debemos de pagar las deudas de Minera México con nuestras utilidades?", dijo en esa oportunidad.
La anunciada huelga de 1.500 obreros de Toquepala y Cuajone podría paralizar la producción de la compañía, pues estos trabajadores representan el 85 por ciento de la fuerza laboral, según Gallegos.
Las minas Toquepala y Cuajone están ubicadas en el sur de Perú y junto con la refinería de Ilo, que no está afectada en la disputa, son los principales activos de Southern, una de las mayores productoras de cobre de Perú.
Grupo México tiene el 54,2 por ciento de las acciones de Southern Perú y el 99 por ciento de participación en Minera México.
Southern Perú espera producir este año unos 850 millones de libras de cobre frente a los 800 millones del 2003, debido a las mejores leyes en sus minas de Cuajone y Toquepala.
Si usted tuviera cualquier pregunta o quisiera anunciar en Peru.InfoMine.com, sírvase contactar a Lola Rivera.
CareerMine welcomes our latest "Employer of Choice" - Cortez Gold Mine. Please look at their current openings and all our other Employers of Choice career opportunities. We work closely with our Employers of Choice to help them with their recruiting needs. To find out more about becoming an Employer of Choice please email Renee and she will be happy to assist.
written by Bernard Aubé, EnvirAubé
Although many different biological and chemical technologies exist for treatment of acid mine drainage (AMD or ARD for acid rock drainage) and smelter effluents, lime neutralisation remains by far the most widely applied method. This is largely due to the high removal efficiency of dissolved heavy metals combined with the fact that lime costs are low in comparison to alternatives. Although the basic mechanisms behind lime treatment are very simple, applying any of the different processes can provide numerous challenges for both operating and cost efficiency.
This paper explains the basic chemistry involved in treating metal-bearing waste waters. Different processes are described and compared, as linked to existing treatment systems. The systems described include several high-density sludge (HDS) processes for the removal of heavy metals such as iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), and cadmium (Cd). More specific processes for the removal of arsenic (As) and molybdenum (Mo) are also detailed. Scaling problems, sludge disposal, and cost efficiency are addressed in sufficient detail to be useful to mine-site operators. More... [PDF - Adobe Acrobat Reader required].
You're entitled to a better Web search
Here's a tip to make your online search experience better. Suppose you want to make a killing in gold investment. So you type gold into a search engine on the Web ... and you get 10,659,157 matches, including 991,450 sites on how to make gold out of lead and aardvarks!
You need to narrow your search to sites that are serious about gold. Enter the title followed by a colon and then your search term. For example, try title:gold and you'll get sites with the commodity in their title - not necessarily in their URL, but in their official title, like "The Gold Page" or "The Gold Miner". Using the title prefix increases the likelihood that the sites found by a search engine really have something to do with the subject.
This trick works for several search engines like Yahoo, HotBot, AltaVista and InfoSeek, though with Yahoo you can also just use the letter t with a colon, as in t:gold.
"EduMine Site Enrollment for Companhia Siderúrgica Nacional (CSN) in Brazil"
Companhia Siderúrgica Nacional is a listed public company, with shares traded on the São Paulo and New York (NYSE) stock exchanges, CSN is one of the largest and most competitive integrated steel companies in Latin America. With an annual production capacity of 5.8 million tons and around eight thousand employees, CSN is focused on steel production, mining and infrastructure. Site enrollment provides unrestricted access for personnel at CSN's Casa de Pedra and Arcos mine sites to the full range of EduMine resources for technical reference and self-learning. The Campus also provides a platform for professional development programs tailored to corporate requirements and objectives. More...
Christmas is a time when everybody wants his past forgotten and his present remembered. What I don't like about office Christmas parties is looking for a job the next day.
- Phyllis Diller
The Supreme Court has ruled that they cannot have a nativity scene in Washington, D.C. This wasn't for any religious reasons. They couldn't find three wise men and a virgin.
- Jay Leno
A Christmas shopper's complaint is one of long-standing.
- Unknown
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Here's a sample of the information on "Gypsum" available on InfoMine. This is just an example of how our search provides excellent and pertinent results for any topic you wish to explore. Why not try your own favorite topic now? |
This article is copyrighted by the author and all rights reside with Sid Perkins
 Discovery about gem's structure overturns old theory
In London in the mid-1870s, 25 shillings-about $85 in today's terms-went a long way. You could buy 7 grams of gold, 40 liters of rum, or about a half kilogram of opium. Where you couldn't get a bargain, however, was the jewelry store. That same amount of money bought just 1 carat, or 0.2 gram, of a gem called tiger's-eye. When rich sources of that precious stone were found in western South Africa in the 1880s, prices plummeted. By 1900, tiger's-eye was considered merely semiprecious. Today, a savvy shopper can purchase the gem for about $1.50 per carat.
The passage of time has transformed more than the gem's price. Recent research has upended a 130-year-old theory about how tiger's-eye forms. As a result, scientists soon will be scrambling to update everything from mineralogy textbooks to museum displays.
In its natural state, tiger's-eye is an unremarkable rock with a dull sheen. When polished and illuminated, however, the stone reflects a narrow band of light that changes position as the gem is turned back and forth. This effect, called chatoyancy, gets its name from the French phrase for "cat's eye" because of its resemblance to a feline's slitted pupil. Chatoyancy occurs when light reflects from minute, parallel ridges, fibers, or tubes within a transparent material.
Early in the 1800s, mineralogists recognized that tiger's-eye was a fibrous variety of quartz, or silicon dioxide. In 1873, the German mineralogist Ferdinand Wibel learned more. While studying the chemistry of hawk's-eye, a blue form of tiger's-eye, he found that the gem was almost entirely quartz but that it also contained fibers of crocidolite, an often bluish, iron-bearing form of asbestos. Wibel proposed that hawk's-eye forms in Earth's crust when quartz dissolved in hot water infiltrates spaces between crocidolite fibers and then slowly replaces the asbestos' molecules.
Brown tiger's-eye, Wibel said, comes after yet another step. It results when chemical reactions transform some of the iron in the bluish crocidolite into brownish iron oxide.
 The idea that tiger's-eye is a pseudomorph-a mineral in which crystals of one material take on the form of another, which it replaces atom by atom-held sway for more than 125 years. In fact, tiger's-eye is cited in many textbooks as a classic example of a pseudomorph, says Peter J. Heaney, a mineralogist at Pennsylvania State University in University Park. During his own efforts to understand the processes underlying pseudomorphism, Heaney examined thin samples of tiger's-eye under a microscope and realized that Wibel was wrong.
Heaney expected to find that the quartz in tiger's-eye is chalcedony, a form that typically consists of fibrous, defect-riddled crystals less than 1 micrometer in diameter. Instead, Heaney was surprised to discover relatively fault-free, column-shaped quartz crystals that measured more than 100 micrometers across and up to 10 millimeters in length. Pseudomorphism doesn't produce such a uniform crystal form.
Heaney and his Penn State colleague Donald M. Fisher suggest that the crystal structure of tiger's-eye forms via a so-called crack-seal mechanism. In such a process, quartz and crocidolite crystals simultaneously condense from hot, mineral-rich fluids coursing through a tiny crack in a rock and grow to fill it. Repeated episodes of fracturing lead to more cycles of simultaneous, crack-filling growth of the two crystals.
In the tiger's-eye samples that Heaney studied, crocidolite fibers often ran parallel to the quartz columns. In some cases, however, the angle between the crocidolite and quartz was as much as 30°. Because, in those instances, the reflected cat's-eye bands of light were perpendicular to the crocidolite fibers, the scientists conclude that in tiger's-eye the chatoyancy arises from the crocidolite fibers, not the quartz.
So, why did it take 130 years for scientists to replace Wibel's tiger's-eye theory? After all, the techniques that Heaney used-optical and electron microscopy and X-ray diffraction-aren't new. The short answer, says Heaney, is that nobody had bothered to look. "Scientists merely accepted the old explanation, as I had," he explains. Also, because tiger's-eye is only a semiprecious stone, it hadn't attracted enough attention to merit a detailed investigation, he notes.
"It tickles me how [this finding] counters the longstanding assumption about how tiger's-eye forms," says Jeffrey E. Post, curator of gems and minerals at the Smithsonian's National Museum of Natural History in Washington, D.C. Says Post, who supports the new interpretation: "Sometimes an explanation is so pat that no one thinks to challenge it." Tickled or not, Post joins the legion of curators in museums worldwide who will need to revise their mineralogy displays. But that's okay, he quips, because it's going to be even tougher for all those textbook editors.
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Season Greetings From The Staff of InfoMine!
