Environmental aspects
In recent years, the cement sector has engaged in a major effort to research and implement systems enhancing the sustainability of its manufacturing processes.
Nonetheless, the production of cement is associated with such environmental effects as the following:
- The exploitation of quarries implies an environmental impact derived from the occupation of territory (visual impact) and the activities undertaken during operation (explosions, crushing and transport).
- The handling, storage and processing of powdered materials has been linked with the emission of particles, an aspect that represents the greatest historical impact of cement plants.
- The use of cement kilns gives rise to the emission of combustion gases into the atmosphere. However, the manufacture of cement provides a considerable potential to contribute to the environment by dealing with the waste from other industrial activities through the recovery of energy or materials.
Despite everything, clinker furnaces do not generate waste nor discharges of waste water.
On the other hand, the air emissions from this device originate in the chemical and physical reactions produced by the treatment of the raw materials and in the combustion processes.
The main components in these gases are the nitrogen from the combustion air, CO2 from the decarbonation of limestone and the combustion process, steam from the water in the raw materials and the combustion process as well as oxygen.
Nonetheless, before being emitted into the atmosphere, the dust is removed from all the emissions using bag filters and the particles collected are fed back into the manufacturing process.
Similarly, these gases contain a small proportion of particles, sulphur dioxide, nitrogen oxides, carbon monoxide, as well as chlorides, fluorides, organic compounds and heavy metals.
In order to reduce gradually the main emissions in the cement manufacturing process, the sector signed a five-year Voluntary Agreement with the Ministry of the Environment in 2001, setting out the environmental targets associated with the application of the Best Available Technologies (BATs).
The renewal and signing of a further Agreement with the Secretariat for the Prevention of Pollution and Climate Change represents an ambitious sectorial plan currently under way to reduce emissions levels and the consumption of non-renewable fossil fuels even lower, at the same time as an effective and safe response is given to society’s demands for waste treatment.
Furthermore, since 2000, the cement industry has voluntarily collaborated with the Ministry of the Environment in the production of the National Dioxin and Furane Emission Inventory, demonstrating through the measures implemented that the sector is not a significant source of emissions for this kind of pollutant.
