We live in the industrial age, when the materiality of the world around us is being more and more impetuously involved into the bottomless scope of consumer interests. There are more things around us made of radically transformed elements of inanimate nature. They are plastics, and metals, and glass, and various composites. They are in a huge amount, but insatiable consumption thirst requires more and more...
Consuming delightedly the environment converted for their needs, people don’t think a lot about the price of such a global alteration. But they really should. Because in the process of getting 1 ton of material with improved consumer characteristics up to 10 tons of much degraded material – so-called industrial waste – are inevitably formed. This inevitability is dialectical by its nature, and with the existing human approach to the material resources it is impossible to circumvent it. As a result, very soon industrial humanity will definitely drown in its own life wastes. The first paroxysms of this are already shaking inhabited world. The red sludge reservoir spill in Hungary, land poisoning by sprawling oil shale ash in the Baltics, dust storms attacking cultivated fields from the coal TPP ash damps, moon landscape of spoil tips and lifeless slagheaps – that is a non-exhaustive list of attributes of industrial prosperity seamy side, which increasingly spoil its attractive face.
What is the fundamental problem of human present approach to resources? It consists in utility in a narrow sense: every element of the material world is considered like a source of a single useful product. Aluminum oxide is extracted from bauxite, iron oxide – from iron ore, combustibles – from coal. All the rest – even if there were gold with diamonds – is ruthlessly sent to the dumps. It is easier and, until recently, it was cheaper.
The main economically affordable and promising energy source, extracted in the EU, is coal. Therefore, the largest thermal power plants and GRES power plants are coal-fired. At the same time, the coal power is among the most environmentally hazardous, because coal has the maximum quantity of wastes per unit of produced energy. In particular, after coal is burned ash and slag wastes (hereinafter – ASW) remain in the quantity which exceeds 1/5 of the amount of source coal and in absolute figures for the EU reaches 1 million tons per year. Except the problem of land allocation for ash dumps, ASW represent serious environmental hazard because they contain soluble substances (including the salts of heavy metals), which are washed away by rain and penetrate into the groundwater aquifers, poisoning them. Hence, ash dumps are the permanent source of water and soil pollution, leading to inefficient use of land resources and reducing market value of land, buildings and structures around. This proves the relevance of the problem of ASW disposal and the need to find new areas of their use.
The main consumer of ASW is traditionally the construction industry, but the interest of builders is mainly limited by fly ash obtained by dry disposal scheme, as it is characterized by relatively stable properties, delivered in dry form, and contains a little coal which is highly undesirable impurity in concretes and mortars. ASW obtained by wet disposal scheme is hardly used because of an unstable granulometric composition, high humidity (200%) and a significant (up to 25%) coal content. Considering that the volume of such ASW 10-15 times exceeds the volume of fly ash, we can conclude that at the most 7-10% of produced ASW are utilized. Tightening of environmental regulations on the content in building materials such elements as chromium, mercury, cadmium and other toxic substances contained in the ash, generally endangers the very opportunity of applying unprocessed ash in the construction.
The second life of ash dumps
Analysis of situation concerned with coal ash TPP utilization demonstrates double nature of existing problem. On the one hand, high-quality ash market is undersaturated, the suppliers are overpricing, but there is still lack of ash. On the other hand, the ecologists tell about vast areas allocated for ash dumps, about millions of tones of needless toxic wastes. How is that possible?
In fact, there is no contradiction; this issue is about different kinds of ash. The one being in demand and in lack of is fly-ash. It is the ash that the smoke coming out of the burners carries away. It is fine, dry, and rather clean. It is easy to work with and to be brought up to the standards requirements. This kind of ash has the only one disadvantage – it is lacking. The smoke carries away at most 10% of ash particles, while the rest of ash goes to the ash dumps. Most often the flow of water is used for this purpose – the so-called “ash removal”. But even if the ash was removing by dry method, it is watered at the ash dump. The result is a different sizes particulate mix, unstable and very wet. It cannot be conditioned – brought up to the standards requirements. And it is very expensive and complicated to dry. So we either have to endure the ash dumps or try to shove this ash and slag mixture somewhere – for example, into the old mines.
Happy age of cheap oil and gas is coming to the end. The increasing number of people on the Earth, from ordinary citizens to big businessmen and governments, is aware of this deplorable fact. And realizing this, they begin finding the ways to prevent impending energy famine. The projects of using the wind, solar, tidal and volcanoes energy appear as the result of such searches. They even try to convert the wastes into energy.
All these projects are very useful in the terms of mind exercising. But at the same time they are rather enlightening as an illustration of the futility of people’s attempts. In fact, the wind is very changeable element that doesn’t want to blow strongly and smoothly around the clock. The sun provides enough energy only in cloudless day and only in a narrow band around the equator. You couldn’t obtain a lot of energy from the tides, to deal with the volcanoes is rather dangerous. Burning of wastes, reducing the severity of some problems, immediately creates other – environmental – because you have to do something with toxic smoke of burning plastic and toxic slag.