Definition of Bauxite
Bauxite is a rock containing aluminum hydroxide that is a principal ore of aluminum. Bauxite is found close to ground surface, between 0.8 to 2 meters deep depending on the geological structure of the region meant for exploitation.
Categorization of Bauxite
Bauxite valuation is categorized and defined based on the silica modulus (mSi) that is the factor of alumina versus silica oxide (SiO2). The higher this ratio, the more precious the bauxite ore.
In Vietnam, the silica modulus of bauxite found in Nhan Co ranges from 3.5 to 7.8 compared to bauxite mined in Indonesia (14 to 18), in Australia (11 to 21), and in India (20 to 25). The lower mSi indicates the poorer quality of bauxite ore.
Summary of Main Processes of Bauxite Exploitation
Digging bauxite does not require tunnels as digging coal mines or other mineral ores. However, it still requires heavy digging equipment and generates tremendous dust that pollutes the surrounding air.
Extracting aluminum from bauxite requires two major processes:
1. Physical excavation, grinding, heating, and chemical treatment to separate aluminum hydroxide from other components originally mixed in bauxite ores.
2. Extracting aluminum via electrolysis at high temperature ( C), low voltage (less than 5 volts) and high amperage (from old timer 70 KA to modern 700 KA) to reduce aluminum oxide to pure aluminum (~99.6%)
The first process of separating of dirt from aluminum hydroxide requires chemical treatment of bauxite ore with water and a sodium hydroxide solution to produce aluminum hydroxide, which is subsequently oxidized in high-temperature kilns to obtain aluminum oxide (Al2O3), also known as alumina.
The hazardous waste of this process is a huge amount of "red sludge" called "silent toxin," that is a toxic combination of iron oxide, silica, calcium oxide, titanium oxide, chrome oxide, zinc oxide, aluminum hydroxide, and organic compounds.
In Vietnam, due to low silica modulus, the first phase of extraction needs repeated treatments of sodium hydroxide and water. Certainly, the more washing and extraction, the more polluted the red sludge waste.
According to projections, the expectation of the first extraction phase is just for 35% to 39% of alumina; then, the subsequent treatments will continue until reaching 98.6% of alumina purity. This process is called the "wet" Bayer process.
Overall, the digging and "wet" wash processes rely heavily on modern mechanical equipments for digging, grinding, rinsing, heating and a low number of labor force. It, however, demands a very large source of water, energy (heat) and chemicals for several treatments.
It also creates environmental problems and pollution that damage the entire ecology system, change the socio-economic structure and can be lethal to human lives of the region.
The second and highly technical process is the transformation of aluminum oxide to pure aluminum. It is more important and requires skilled workers plus advanced technology provisions for high amperage electricity for electrolysis.
In truth, it is a primary concern and difficult blockage for Vietnam where lack of electricity and restrictions on its usage are customary for the city people. This is a factor made much worse in the highlands and rural areas.
The Environmental Impacts Caused by Bauxite Mining
Air Pollution and Acid Rain
Dust is a primarily environmental problem caused by Bauxite mining. Dust absolutely covers very large surrounding areas that affect the habitats, including residential and agricultural neighborhoods of the Bauxite exploitation site. The "red" dust waste from the first process of Bauxite definitely will cling to the income-producing plantations such as coffee, tea, rubber, black pepper and remain on their leaves for a long period of time. This phenomenon is very harmful to the growth of the agricultural products and reduces the productivity of these trees.
This dust consisting of toxic chemicals plus the natural emissions of radiation products as radium, thorium, and beryllium… can in the long run become a cause of lung cancer for residents in the surrounding areas as borne out by statistical data coming from coal mine areas in Western countries.
Moreover, during the separation process, the vapor of sulfur dioxide is formed, and an acid rain is generated due to the chemical blend of sulfurous air and water. This acid rain is the most serious harm to adjacent farms.
Water Pollution
Digging a bauxite site would tremendously damage huge depths of the topsoil level that can never be replenished as in the condition before digging. Besides, it requires an estimated area equivalent to the bauxite site to dump the red sludge.
According to historical data or bauxite exploitation data taken from different advanced countries, the ratio 4/2/1 means that in order for 4 tons of ore to produce 2 tons of alumina, or 1 ton of pure aluminum, 4 tons of red sludge are the result.
When the toxic red sludge is dumped on the ground, its toxic chemicals will be percolated to the underground water table along with rainwater, which would then contaminate the main water source of the highlands region and its people in Dak Nong province.
In addition, the red sludge is carried by rain to the Serepok River and surrounding streams from the Highlands to the Dong Nai River, the main water source provider for Saigon (Ho Chi Minh) city and the southeastern part of South Vietnam.
In sum, this hazardous waste is seriously harmful to a population of 30 million and causes agricultural damage to the highland farms.
Fishery Pollution
The fishing industry will also be damaged due to the poisonous chemicals from the red sludge as fish can subsequently be vanishing or even become extinct. According to researches carried out by American and Italian scientists, red sludge can cause the genetic distortion of fish in the ocean. The health and lives of the people living southeast of Saigon and its fish consumers can be greatly affected as well.
Toxicity Affecting Human Lives
The red sludge puts health and human lives at risk of being lost or harmed due to air, water and fish pollution. The medical statistics prove that prolonged toxicity may cause encephalopathy, osteoporosis, anemia, and possibly Parkinson diseases. An Australian researcher in Australia where bauxite mining is largely developed proved that red sludge causes lung cancer and uterus deformation in rat experiments. The common symptoms of toxicity on humans are dizziness, vertigo, nausea, fainting, or comatose if breathing or taking in a large dosage.
According to OSHA, the sodium hydroxide (NaOH) is the primary waste in red sludge and it is harmful to human beings after prolonged contact, say 15 years. Direct contact may cause skin irritation, or inflammation of the respiratory system such as blistering of the throat, mouth or nose.
The Economic Effectiveness
The Economic effectiveness of bauxite mining depends on the density of aluminum. In general, 4 tons of bauxite yield an average of 2 tons of aluminum oxide and generate 4 tons of red mud in order to produce 1 ton of pure (~99.6%) aluminum.
In order to produce 1.2 million tons of pure aluminum per annum, which is the ultimate goal as spelled out by Vietnam, we can do a simple math and arrive at how large a surface is needed annually for a dumping ground of red mud!
For comparison, 1 hectare of rubber tree plantation yields 1.5 tons of rubber which is equivalent of US$4,500.00 as 2008 market price. Moreover, the land can be subsequently harvested for the next 20 years.
In contrast, one ton of alumina costs only US $270.00 (2008 market price). In order to have the same yield of rubber plantation, it needs to dig 35 tons of bauxite ore. However, the land after exploitation cannot be reused but also generating 40 tons of toxic waste of red sludge and polluted dust.
More specifically, the research inside Vietnam by Nguyen Dong Hai, Ph.D, Nguyen Thanh Son, Ph.D, and Nguyen Ngoc was reported on the VietnamNet web site, shows that the total annual income from Bauxite mining is only 1,450 billion Dong (Vietnamese piasters) versus 2,200 billion for rubber trees and 5,800 billion for coffee trees harvesting for the same amount of land used to produce aluminum in the Highland of Dak Nong,
Hence, the ability to repay the debt for tree investment is 5 times faster than bauxite investment.
According to their calculation, it costs 3,000 billion Dong Vietnam for 4,000 hectares (equivalent to 8,800 acres) of bauxite. However, the same amount of money can be used to invest in 35,000 hectares of rubber trees or 58,000 hectares of coffee trees.
In plus, bauxite exploitation is not tax advantages. It brings in about 30 billion Dong VN versus 701 billion Dong VN for rubber trees and 2,175 billion Dong VN for coffee trees.
In socio-economic standpoint, bauxite mining does not create more jobs to the area because the Chinese labor force and heavy duty digging equipments are utilized.
It requires only 5 thousand laborers for the Dak Nong site (equivalent to 1.25 labors/hectare) as compared to 170,000 laborers for rubber plantation and 590,000 laborers for coffee plantation.
The Social and Cultural Effects on the Ethnic Minorities
There are numerous ethnic groups (about 15) in the Central Highlands of Vietnam and they are very sensitive to the invasion of the Vietnamese (called "Kinh," people from the Capital). Their habitats and lands are getting smaller and smaller due to the encroachments of Vietnamese migration into the area and the infusion of minorities coming from the North, deliberately fostered by the government, which have brought a huge population increase, from an original 1.4 million to an estimated 4 million.
Of the original (native) 1.4 million, about 90% are ethnic highlanders. Now, their estimated number is down to around 400,000. This decrease of their population is due to their retreating deeper into the forest lands to the West and/or to the neighboring countries of Laos and Cambodia.
According to plan, Vietnam is expected to develop 5 more locations in Dak Nong province beside Nhan Co (area: 510 Km2) such as: Trung Duc (354 Km2), Dak Song (300 Km2), Gia Nghia North (329 Km2), 1 Thang 5 (197 Km2), Quang Son (159 Km2). All planned areas of bauxite exploitation would come to more than 1/3 of the surface of Dak Nong province.
Digging Bauxite in this area is a serious matter of concern to the people of Dak Nong because with their agricultural land being invaded and further restricted starvation becomes a distinct possibility. Migration (move to another area) and separation of families will become necessary for survival, therefore, it will disturb its social structure and may damage family values due to the Chinese occupation and cultural invasion.
Limitations on Aluminum Processing
The electrolytic process (the second phase) to produce the end product known as pure aluminum is beyond Vietnam's capability in the present conditions due to lack of water and the absence of low cost electric power.
Water and electricity are sine qua non requirements for processing bauxite into aluminum that pose the biggest obstacle for the Communist government at the present time. It needs 18 billion kilowatt hours (KWH) to generate 1.2 million tons of pure aluminum per year. The cheapest cost is 3 cents US$ for one KWH (equivalent to 540 Dong Viet Nam) in order to break even for 1 ton of aluminum product. In Vietnam, the total amount of KWH of electricity available to the entire nation in 2008 is 58.4 billion KWH. How can Vietnam be expected to provide that kind of power capacity at the lowest cost?
Dalat, the national tourist spot and largest city in the highlands, is currently still restricted in its use of electricity and water for its residents.
To achieve their goal, the Chinese plan to deploy the construction of an hydro-electric plant at Dat Tit with the capacity of 144 MW and use water from four lakes along the Serepok River for a bauxite site at Nhan Co. But this is impossible and its project schedule cannot be met because of the difficulties in developing the region's infrastructure.
The Nhan Co project, which is expected to generate 600,000 tons of aluminum per year, requires 4 million cubic meters of water and this is something that cannot be supplied in a short period of time.
In sum, the bauxite mining in the Central Highlands of Vietnam is an IMPOSSIBLE project due to inadequate resources of water and the demand of huge amounts of electricity.
Conclusion
The environmental and humanitarian concerns due to bauxite exploitation in the Central Highlands of Vietnam (Tây nguyên) resulting from hazardous waste are simply too risky and they will severely impact the entire region and Vietnam.
Its exploitation will cause the hazardous waste of chemicals and polluted parameters that may be lethal to human life and lead to the destruction of the region's ecology in which agricultural land cannot be recovered for generations. It also dismantles and changes the social structure of families but does not create any economic effectiveness and tax advantage for Vietnam and its people.
Furthermore, the infrastructure of the region is not developed enough for the transportation of heavy equipments and an enormous amount of supplies needed for the project.
It may, however, achieve its goal and expectations of the Communists in Vietnam and China.
Mai, Truyet Thanh, Ph.D.
President,
Vietnamese American Science & Technology Society
West Covina, May 11, 2009
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