The International Cyanide Management Code For The Manufacture and Use of Cyanide In The Production of Gold referred to as the Cyanide Code is a voluntary program designed to assist the global gold mining industry and the producers and transporters of cyanide used in gold mining in improving cyanide management practices, to publicly demonstrate their compliance with the Cyanide Code through an independent and transparent process. The Cyanide Code is intended to reduce the potential exposure of workers and communities to harmful concentrations of cyanide‚ to limit releases of cyanide to the environment‚ and to enhance response actions in the event of an exposure or release; the Cyanide Code was one of the earliest standards and certification programs developed for the minerals sector. Today, it is amongst the most established certification programs in the mining industry; the program's audit process and the transparency of audit results set it apart from other voluntary industry programs. Cyanide is a general term for a group of chemicals containing nitrogen.
Cyanide compounds include both occurring and human-made chemicals. In nature, cyanide is present in plants including bitter almonds apples, apricots, lima beans, sorghum and bamboo shoots; some scientists suggest that the reason why these plants contain cyanide, which can be toxic, is that evolution has designed them to discourage insects from feasting on them. Although cyanide can be toxic to humans, eating cyanide-containing foods is not harmful because cyanide is present in low amounts, is contained in seeds which are discarded, or is washed away when the food is prepared. Cyanide can be acutely toxic to humans, other mammals and aquatic species, as it interferes with oxygen utilization. Cyanide does not bioaccumulate, a non-lethal dose is metabolized in the body. Cyanide is not teratogenic or mutagenic. Cyanide comes in many forms including hydrogen cyanide, cyanogen chloride, salts such as sodium cyanide or potassium cyanide. In manufacturing, cyanide is used to make paper and plastics. Cyanide salts are used in metallurgy for electroplating, metal cleaning, removing gold from its ore.
Cyanide gas is used to exterminate pests and vermin in buildings. Cyanide is a basic building block for the chemical industry. About 80% of global cyanide production is used to synthesize a wide range of industrial organic chemicals such as nylon and acrylics, it is estimated that less than 20% of manufactured cyanide is used in mineral processing in the form of sodium cyanide. Sodium cyanide has been used in gold mining since 1887 because it is one of only a few chemical reagents that will dissolve gold in water; this allows the efficient extraction of gold from low grade ore. Commercial gold mining operations use dilute solutions of sodium cyanide in the range of 0.01% and 0.05% cyanide. Cyanide should be controlled on mine sites, proper management requires that certain precautions be taken to limit worker exposure and to prevent chemical solutions containing cyanide from entering the environment; the most-used process of removing gold from ore is through leaching. In the leaching process, sodium cyanide is dissolved in water where, under mildly oxidizing conditions, it dissolves the gold contained in the crushed gold ore.
The resultant gold-bearing solution is called'pregnant solution.' Either zinc metal or activated carbon is added to the pregnant solution to recover the gold by removing it from the solution. There are two main leaching methods for gold extraction using cyanide; the first is'heap' leaching in which the dilute cyanide solution is sprayed on large piles or heaps of coarse gold ore. The solution percolates through the pile dissolving the gold and the pregnant solution is collected; this method is used for ore with lower concentrations of gold. The other method is'vat' leaching in which the process is similar but the gold ore is finely ground and leaching takes place in a tank or vat. Vat leaching is used for ores with higher concentrations of gold due to the cost of milling the ore to a small particle size. Alternative lixiviant chemicals to cyanide have been investigated for many years, but they are less effective and/or economical than cyanide, they present environmental risks that can be greater than cyanide.
Because cyanide is toxic if not properly handled, its use is regulated in most countries. Despite regulatory and voluntary safeguards, some jurisdictions have banned its use in gold mining; these include Slovakia, the Czech Republic and Hungary. Several provinces in Argentina prohibit the use of cyanide in mining. In the U. S. the state of Montana has taken action to ban cyanide in gold production. Cyanide, a toxic chemical, has been the most used reagent for extracting gold from ore for the past century; the Cyanide Code grew out of the first-of-its-kind workshop of multi-stakeholders held in Paris in May, 2000 convened to consider developing a code of best practice for the use of cyanide in gold mining in response to a tailings spill from the Aural Mine at Baia Mare in Romania in January 2000. The meeting was co-hosted by The United Nations Environment Programme and the International Council on Metals and the Environment. Workshop participants were 40 representatives of such diverse organizations as the Worldwide Fund for Nature, the Mineral Policy Center, the Sierra Club, the World Gold Council, along with representation from the U.
Diana M. Bautista is an American neuroscientist known for her work on the molecular mechanisms underlying itch and pain, she is a full professor of cell and developmental biology in the Department of Molecular and Cell Biology and is affiliated with the Helen Wills Neuroscience Institute at University of California, Berkeley. Bautista was the first member of her family to graduate high school. While taking a break from pursuing a fine arts degree, she worked for an environmental group in Chicago, which sparked her interest in the intersection of chemistry, the environment and human disease; this lead her to the University of Oregon to study environmental science. While working in the laboratory of Peter O'Day, she became interested in cell signaling and the nervous system. Dr. O'Day encouraged her apply for graduate school where she chose to join the laboratory of Richard Lewis at Stanford University. For her graduate studies, Dr. Bautista used electrophysiology and calcium imaging to characterize how plasma-membrane calcium-ATPase and Ca release-activated Ca channels regulate calcium levels in T-cells.
As a post-doctoral fellow in David Julius's lab, she characterized the response profiles of TRPA1 and TRPM8 and the molecular target of Szechuan peppers. Dr. Bautista helped show that allyl isothiocyanate, a pungent chemical found in wasabi and other mustard plants, potently activates TRPA1. In a subsequent study, she demonstrated that compounds found in garlic plants, allicin and DADs activate TRPA1. Interestingly, both allicin, DADs and allyl isothiocyanate share structurally similar motifs, suggesting that Allium and Brassica plants independently derived chemical mechanisms to activate TRPA1 to deter potential predators. TRPA1 is targeted by environmental irritants like acrolein, found in tear gas and vehicle exhaust. Using TRPA1-deficient mice, she showed that TRPA1 is activated by acrolein and allyl isothiocyanate, which in turn depolarizes nociceptors and elicits inflammatory pain. Dr. Bautista developed TRPM8-deficient mice to demonstrate, using electrophysiology and behavioral studies, that TRPM8 is the target of cold and menthol stimuli.
In 2008, Bautista started her own lab at University of California, Berkeley and is a Rita Allen Scholar. 2005-2010 Burroughs Welcome Fund Career Award in Biomedical Sciences2008-2009 Sloan Foundation Research Fellowship2009-2010 Hellman Family Faculty Fund Award2009-2011 McKnight Endowment Fund for Neuroscience Scholar Award2009-2013 Pew Scholar in the Biomedical Sciences2010-2012 Rita Allen Foundation Pain Scholar 2010 Diana along with fellow UC Berkley faculty member, Amy Herr received New Innovator Award by the National Institutes of Health.2010-2012 Rita Allen Foundation Pain Scholar2012 UC Berkeley Prytanean Faculty Award for outstanding research, teaching & outreach2013 International Forum for the Study of Itch, Handwerker Prize for Research 2014 Diana along with Feng Zhang, an assistant professor at the Massachusetts Institute of Technology were given The Young Investigator award by The Society for Neuroscience today 2016 HHMI Scholar 2016 UC Berkeley Class of 1949 Endowed Chair