Study shows that self-burning coal mining residues have a negative environmental impact

Abridged version in English: Diana Taborda

A study conducted by the Department of Earth Sciences (DCT) of the Faculty of Sciences and Technology of the University of Coimbra (FCTUC) has concluded that self-burning coal mining waste has a negative impact on the environment due to the production of acid drainage, which can affect the soil and ecosystems in the surrounding area.

Research on self-burning mining waste in Portugal, which began in 2007, has as its main goal to identify and analyse the environmental impacts of this process, particularly on soil, water and atmosphere.

"The most significant impact is likely to be related to the emission of volatile organic compounds during combustion. Substances such as polycyclic aromatic hydrocarbons and other organic compounds have been detected, which are harmful to human health. This can be particularly worrying when the self-combusting piles are close to inhabited areas", explains Joana Ribeiro, DCT professor and author of the study.

The researcher considers that “it is very important to compile an inventory of the existing coal waste piles in Portugal, their characteristics and how they are deposited, as well as their location in forest areas. By doing this, the risk of ignition and subsequent self-combustion of coal waste piles could be minimised through appropriate forest and land management”.

The study also included researchers from the University of Porto.

The scientific article "Prediction of acid production potential of self-combusted coal mining wastes from Douro Coalfield (Portugal) with integration of mineralogical and chemical data", published in the International Journal of Coal Geology, is available here.