Gold is an obvious sign of wealth and people who are wealthy flaunt as much of it as they can. Just before Dussehra or Diwali our TV screens are full of advertisements for gold jewellery, and no Indian wedding would be complete without lots of gold being on display, worn either by the guests or the bride and groom. Gold is used everywhere, from wedding rings to roofs, zari sarees, fillings in teeth….
Gold is valuable for two reasons: first it is relatively rare as compared to other metals such as iron or copper. Second because it is soft, gold is a very malleable metal. A single gram of it can be beaten and flattened into a sheet as large as one square metre. Its malleable character is useful because it allows gold to be used to cover or plate things, for example the domes of buildings. But apart from such uses, pure gold is too soft for ordinary use and is hardened by ‘alloying’, which means mixing with silver, copper, and other metals. When it is alloyed the term ‘carat’ is used to indicate the amount of gold present, with 24 carats being pure gold and less carats being more of other metals and less gold. Alloys can be easily fashioned into long-lasting jewellery and gold was probably the first metal to be used by man in ornaments. It was used in nearly all ancient civilisations.
But this valuable and beautiful metal causes a lot of problems. This is firstly and obviously because it is valuable; from wars to pirates to burglaries we have all read stories about what people do for gold. But now even big mining companies are willing to become the bad guys and throw out local people and plunder and destroy the environment in search of gold.
The process of mining gold or any other metal is very destructive to the environment. Modern gold mining is generally done as open pit mining where huge gaping holes are dug to bring out the ore, and all that is not gold is just thrown away into the surrounding areas. A single gold mine in Papua New Guinea, the Ok Tedi mine, generates 200,000 tonnes of waste every day, which is more than all the waste produced by all the cities in Japan, Canada and Australia put together. It has been calculated that one 18 karat gold ring produces more than 18 tonnes of mine waste.
The other problem is with the process of purifying gold. Gold occurs as impure pebbles called nuggets or as grains in exposed rocks, often in river beds. Most commonly it is found as gold ore in underground deposits. Except in very rare cases it is present in very tiny quantities and needs to be concentrated and have all the impurities removed. There are many ways to do this, but the two simplest and cheapest methods are to do it chemically or by making a mercury amalgam.
Both these processes use chemicals that are not just slightly, but actually very very poisonous -- cyanide or mercury. In the cyanide process the ore is crushed, piled into huge heaps and sprayed with cyanide, a technique called ‘heap leaching’. The cyanide trickles down through the ore, bonding with the gold. The resulting gold-cyanide solution is collected at the base of the heap and pumped to a factory where the gold and cyanide are chemically separated. The cyanide is then stored in artificial ponds for reuse. The leached ore with gold removed, which still contains some cyanide, is stored in dams called tailings dams. The leaching process takes a few months, during which the cyanide is kept soaking into the heaps. Then more fresh ore is dumped onto the heaps and the process goes on. Keep in mind that cyanide is one of the most poisonous substances known to man and even a rice-grain-sized dose of cyanide is fatal.
The Omai gold mine in Guyana is one of the largest open-pit mines in the world and is owned by a Canadian mining corporation. Its tailings dam collapsed in 1995, releasing some 3 billion cubic litres of cyanide-laden tailings into the nearby river. All 51 km of the river had to be declared an official disaster zone.
The mercury process is slightly different but just as polluting. Gold ore is crushed till it is quite fine and then it is mixed with mercury to form an amalgam. The amalgam is thicker than the rest of the crushed ore so it is forced through a series of ever smaller sieves where the amalgam stays behind, while the rest falls through. The leftover waste — which now contains a lot of the unused mercury — is returned to wherever the gold was taken from, mines or river beds, which pollutes large areas around the mining areas. A further source of pollution occurs when the gold-mercury amalgam is broken down again to leave behind pure gold. This is done by heating and vaporising the mercury. The poisonous mercury becomes a gas, making it even more dangerous, this time to the miners who breathe in the fumes. Mercury damages the lungs, kidneys, and the nervous system and can cause birth defects. For each gram of gold purified, two grams of mercury are released into the environment.
While the cyanide process is generally used by mining companies, the mercury process is a traditional, old process mostly used by individual or small-scale mining, especially by poorer people in developing countries. This means that there is rarely anyone to check the health of workers or control pollutants being released into the environment.
This brings us to another reason why people are fighting gold mining. Gold is often found in traditional territories of indigenous peoples, whose land rights are usually not clearly recognised. They have no protection against big companies taking over their land, kicking then out and then damaging the land by mining. When local people are employed they are given the most dangerous work no one else is willing to do. In one country, Ghana, just between 1990 and 1998, more than 30,000 people were displaced by gold mining operations in one district alone. In South Africa, which is now the world's largest gold producer, a minister once said that for each tonne of gold mined, one life was lost and 12 people seriously injured.
What makes people angry about all this is that the things gold is used for are not really necessary. Gold is not really irreplaceably useful. True, some is used in electronics because it has high electrical conductivity, but most, more than 80%, is made into jewellery and used to display one’s social status.
--Manoj Nadkarni
InfoChange News & Features, May 2006 |
