Environmental Technologies and Eco-innovation in the Czech ...

a solid phase (based on coke), a liquid phase and a gas phase. With this technology,
all organic substances may be treated, i.e. in terms of waste it applies to bio-waste
and used tyres. The utilisation of all three product phases depends on the nature of the
input raw material (waste). The gas obtained after treatment can be used to produce
electricity or thermal energy. The solid phase in the output is a slag in which the
pollutants are bound by strong bonds with zero extractability. Therefore, it is suitable
as an inert building material. For the pyrolysis of used tyres, the liquid phase in the
output is diesel oil.
The ENVICRACK cluster (the cluster of renewable resources) deals with technology
development and putting its implementation into practice in the Czech Republic.
It associates entities interested in the research and introduction of pyrolysis into
practice.
8.4 | Flotation and reflotation
Flotation is a physical-chemical method of separation 6 that uses different
wettability 7 of the surface of various minerals. The flotation technology appears in new
applications such as the decontamination of soils, the flotation of black printing ink
during the processing of waste paper and the recycling of plastics (plastics flotation
makes use of their different densities; on an industrial scale it is used for the sorting
plastic waste).
A specific flotation technology is reflotation, which is flotation carried out on raw
materials that have already undergone the flotation treatment. Reflotation is used
to recover materials from waste in the treatment of coal that is kept in settling
pits 8 and still contains a relatively high percentage of usable materials. In the
settling pits, it is not possible to ensure stable and quality raw materials extracted by
hydraulic mining, because during sluicing (on the order of several years) the settling
pits have changed the points of sludge inflow and the sludge properties are therefore
very different.
6 separation – a process of treating raw materials or waste when useful components of a treated raw material are transformed
into a concentrate and undesirable components
7 wettability – the adhesion of mineral surfaces to water; a physical-chemical property of solid particles of minerals important
for flotation; wettability depends on the surface tension of a liquid and on the properties of the surface of a wetted material
(composition, crystalline structure, etc.)
8 settling pit – an outdoor sedimentation basin for the settling and dewatering of solid compounds from WWTP waste, i.e. finegrain
waste from coal treatment
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