Converting Coal Waste into Valuable Compounds

Converting Coal Waste into Valuable Compounds

Converting Coal Waste into Valuable Compounds

West Sumbawa, Aug 10, 2020 - Do you know that the mining industry supports roughly 45% of the world’s economic activities? The raw materials extracted by mining companies are powering the world’s growing population and its dependence on computers, gadgets and other technologies.

Keeping tabs of the mining industry’s progress in adopting more sustainable approaches should be in everyone’s interest, as mining activities have major impacts on more than 10 of the UN's 17 Sustainable Development Goals (SDGs). Many scholars, activists, and interest groups have been advocating for mining companies to lower greenhouse gas emissions, transition the energy source to lower-carbon alternatives, and many others.

We at Amman Mineral are fully aware that the sustainability of the environment, wildlife and communities surrounding Batu Hijau site is as important as the sustainability of our mining activities. Therefore, sustainable operations have become our business strategy, as they can also improve operational efficiency and lead to short term as well as long term benefits. As part of the strategy, we recently convert our coal waste into valuable compounds.

Since 2000, Batu Hijau site has produced 3.6 million tons of copper and 8 million ounces of gold. The electricity for our mining activities, including ore mining, concentrate processing, and daily living is generated by four units of coal-fired power plants located in Benete Port area, with a total capacity of 112 MW. Unfortunately, this means our power plants also produce 15,600 tons of waste in the form of coal ash—also known as FABA (Fly Ash and Bottom Ash)—per year. Fly Ash, the fine particle ash collected by media filter, and Bottom Ash, the heavier ash collected in the Submerged Chain Conveyor, are stockpiled in a landfill at the power plant area.

Nevertheless, we see opportunities to change this FABA waste into the compound for road-paving in the reclamation area. At the end of every production day, FABA, which is made up of 80% Fly Ash and 20% Bottom Ash, is transported from the landfill to the mining area. We mix FABA waste with soil that reduces its acidity level, solidifies the soil and increases soil quality, making it an ideal material to pave roads. After conducting a water runoff test, the test result of the roads made from this mixture came back negative for pollutants and, in fact, met the requirements from the Ministry of Environment and Forestry, who granted Amman Mineral permit for FABA utilization in May 2019. Currently, 94% of FABA side-produced at the Batu Hijau power plant has been used in reclamation areas around the mining site, providing even-surfaced roads for our heavy vehicles to pass through, while the rest is used as raw material for mixing concrete.

This alteration becomes robust evidence that sustainable practice in mining industries can also improve operational efficiency by reducing the cost for road maintenance. It also becomes part of our meaningful actions to implement a circular economy, a system that aims to eliminate waste and the continual use of resources.

As the saying goes “one man’s trash is another man’s treasure”. It reminds us to always find innovative ways to utilize our waste into valuable resource, that is useful for the community and the sustainability of our environment.