Lignite Mines

photography — Braunkohletagebau Amsdorf, Germany. Public Domain.

Lignite is a sort of coal, it is also called brown coal because its color is brown. The better quality hard coal, on the other hand, is usually black. Coal is produced from plants that do not decompose due to the exclusion of air, so that the organic hydrocarbon compounds are not decomposed. Nevertheless, it changes due to coalification, the pressure of the overlying rock and the higher temperature in the earth's interior. In the beginning, the substance is called peat, after a certain time it becomes lignite. Coalification means an increase in carbon content, a reduction in sulphur, water and highly volatile gases. As a result, the coal increases in weight and becomes somewhat harder, at the same time, it is a compression, the seam becomes thinner.

The lignite is therefore relatively young and lies very close to the surface. This allows very effective mining in opencast mines, huge excavators first remove the overburden, then they shovel the coal onto conveyor belts. In most cases, these conveyor belts lead directly to the consumer, a lignite-fired power plant. The high content of admixtures leads to a large number of exhaust gases which are harmful to health and the environment. Nowadays, these are largely captured by exhaust gas filters. Primarily, lignite is used to produce electricity, but it can also be used for district heating.

Another use is as a heating material. For this, however, the coal has to be processed. The classic method is the production of briquettes, in which the lignite is pressed into handy cuboids. These can be stacked, transported on pallets and burned in coal stoves. This use is in sharp decline, not only because it requires heating by hand, but also because of the fine dust it produces.

A major problem with lignite mining are the huge opencast mines. They are obviously psychologically effective, as the protests in Hambach Forest have proven. This is factually unfounded because it is probably the most harmless mining of all. The energy consumption is minimal, the landscape is cleared, but can be renaturalised afterwards with little effort, and often a beautiful bathing lake is created. Uranium mining produces radioactive tailings, the mining of raw materials for batteries releases heavy metals and other toxins into the environment, but when a few trees have to be felled for lignite mining, the outrage is great. In contrast, recultivated opencast mines often become breeding and resting areas for birds of national importance and are declared nature reserves. The real reason why lignite is not a good energy source, namely the extremely high carbon dioxide production during firing and the other toxins that are released, have obviously been forgotten.