VietNamNet Bridge – The recent red-mud spill in western Hungary, which forced hundreds of local dwellers out of their homes, contaminated the soil and decimated wildlife, has raised the concerns about bauxite mining projects in Vietnam, said Duong Van Hoa, Deputy General Director of the state-owned Vietnam National Coal Mineral Industries Group (Vinacomin), who directly oversees Vinacomin’s bauxite projects.

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According to the design of two underway bauxite mining projects in Vietnam’s Central Highlands, the red-mud disposal reservoirs will be built in several phases. The reservoirs will be divided into several sections, with a dyke system to prevent rainfall. In the first phase, eight sections will be built to keep red mud discharged within 12 years. They will be built one after each other to avoid mud spill.

“According to the design, each section has a standby one, meaning after one year discharging red mud to a section, there will have a standby disposal section for the next year. The construction of disposal reservoirs will be carried out in parallel with the construction of alumina plants,” Hoa said in an interview with a local newspaper, Tien Phong.

He also said that Vinacomin will check the design of red-mud disposal reservoirs in the Tan Rai alumina plant following the recent red-mud spill in Hungary.

Hoa said the red mud incident in Hungary has attracted the attention of the Party and State leaders as well as relevant ministries and agencies, and Vinacomin also watched closely the red mud spill of the world’s first aluminum production industry in the last 100 years.

He said work on the Tan Rai alumina plant is entering its final stage. It is expected that the project will finish later this year, and the first product will come out early next year. The project is about three months behind schedule due to the rainy season and several problems when importing equipment. However, the delay is not too serious for a project worth VND12 trillion (US$615 million).

According to Hoa, the plant is using Bayer technology. The equipment is not wholly made in China but also in the EU, Japan and some in Vietnam. The main contractor is China’s Chalieco. The disposal reservoir is designed by Samy Consulting Institute in Shenyang, one of the leading design institutes in China’s aluminum industry.

“The construction of the red mud disposal reservoir in Tan Rai is completely different from the one in Hungary. The one in Hungary is built on the lowlands while the Tan Rai disposal lake is located below the valley, protected by the surrounding hills, Hoa explained.

Hoa also told Tien Phong that to prevent flooding in case of heavy rains or flash floods, Vinacomin have designed the drainage system around the disposal lake to ensure water does not spill over the lake. When flash floods occur, water cannot overflow the lake as the amount of red mud is not higher than the surrounding hills. The group also studied the plan for earthquake resistance. It will review all the designs of the red mud disposal system.

Hoa confirmed that this project can bost economic development in the Central Highlands. The project will gain the profit of 11 percent and provide jobs to 2,000 local workers, and will require more services such as transport, and repairing services.

On October 12, the Ministry of Industry and Trade and Vinacomin, the investor of bauxite mining and alumina processing projects in the Central Highlands, had an urgent meeting about the design of red-mud containing reservoirs.

Meanwhile, Nguyen Dinh Hoe from the Vietnam Nature and Environment Protection Society expressed his worries about Vietnam’s bauxite projects with Tuoi Tre Daily.

“The Vietnamese bauxite mining companies have assured that the red mud will be buried carefully. But it does not mean it will be safe after 20-30 years. It should be noted that the highest content of pH in red mud is 13, which is around 1 million times higher than the safe level,” Hoe said.

“If a similar catastrophe happens in the Central Highlands, the red mud will flow into Dong Nai River, threatening the lives and health of tens of millions of people,” he added.

According to Hoe, around 1.5 tons of red mud is produced from processing 1 ton of alumina. According to an environmental assessment report, the Nhan Co bauxite mining project will turn out more than 11 million cubic metres of waste water and red mud annually. The Tan Rai project may create 80-90 million cubic metres of red mud during its production lifetime. As a result, Vietnam will need huge containment reservoirs to store the mud.

Hoe was not sure about the safety of red-mud disposal reservoirs. “No one knows what will happen when the projects are finished and the investors are no longer responsible for the waste. The huge red mud lakes buried on high terrain which is prone to erosion will be forever a threat to the environment in the central highlands and the lower section of the Dong Nai River,” he remarked.

To prevent a similar catastrophe, according to Hoe, relevant agencies must keep a close eye on the projects, especially the containment reservoirs.

“We should make plans for the future because we cannot guarantee that future generations will be able to ensure the safety of those reservoirs. As proposed by scientists, I think the best answer would be to process the ore in Binh Thuan Province because it would be less dangerous if the waste leaked into the sea,” he said.

According to the US Geological Survey, Vietnam is estimated to hold the world’s third largest bauxite ore reserves, after Guinea and Australia. The majority of reserves is located in the Central Highlands and has only been minimally mined.

Bauxite is typically strip mined and is used to produce aluminum. According to estimates by Vietnam’s Ministry of Industry and Trade, Vietnam’s reserves in the Central Highlands amount to 5.4 billion tons. Despite its large reserves, Vietnam produces only 30,000 tons of bauxite per year.

A draft mining plan for bauxite was approved by the Vietnamese government in 2007. Vinacomin has laid out a plan for six bauxite mining projects covering over 1800 square kilometres in the Central Highlands. The first two processing plants have been contracted to Chalco, a Chinese mining company.

The Nhan Co project in Dak Nong Province and the Tan Rai complex in Lam Dong Province are expected to produce 600,000 tons of alumina per year. Vietnam has indicated that it needs about $15.6 billion to invest in major bauxite and alumina refining projects by 2025. Prime Minister Nguyen Tan Dung has approved several large mining projects for the Central Highlands, confirming that bauxite exploitation is "a major policy of the party and the state."  

Red mud is a solid waste product of the Bayer process, the principal industrial means of refining bauxite to produce alumina. A typical plant produces one to two times as much red mud as alumina. The exact ratio depends on the type of bauxite used in the refining process.

Red mud is composed of a mixture of solid and metallic oxide-bearing impurities, and presents one of the aluminium industry’s most important disposal problems. The red colour is caused by the oxidised iron present, which can make up to 60% of the mass of the red mud. In addition to iron, the other dominant particles include silica, unbleached residual aluminium, and titanium oxide.

Red mud cannot be disposed of easily. Red mud presents a problem as it takes up land area and can neither be built on nor farmed, even when dry. Due to the Bayer process the mud is highly basic with a pH ranging from 10 to 13. Several methods are used to lower the alkaline pH to an acceptable level to decrease the impact on the environment.

In early October, approximately one million cubic metres of red mud from an alumina plant near Kolontár in Hungary were accidentally released into the surrounding countryside in the Ajka alumina plant accident, killing seven people and contaminating a large area. All life in the Marcal river was said to have been "extinguished" by the red mud, and within days the mud had reached the Danube river.

PV