| Abstrakt: |
As a result of coal preparation though hydrogravitational and floatation methods, significant quantities of coal slurry, containing solid particles with diameters mostly under 1 mm, of which approximately 20% are coal fines, have been generated over the past years. They have been deposited in coal tailing ponds, and can therefore be extracted and used as a secondary source of solid energetic fuel. The technology used for the recovery of the coal fines in the gross slurries impounded in the two tailing ponds, belonging to the Coroiesti Valea Jiului Preparation Plant, which are used as combustion fuel in thermal power plants or any other combustion installations, consists of the combining of attrition-separation processes, primary centrifugal field concentration performed by a coarse hydrocyclones unit, connected at its overflow compartment with a fine hydrocyclones unit, whose underflow product is passed through a dehydration sieve, while its overflow residue, containing a high quantity of fine clay particles is deposited in a sedimentation compartment of the pond under exploitation. The resulting waste waters are completely recycled throughout their course through the installation, while technological water is used for the achieving of the necessary working dilution, spraying on the sieves and cooling of the equipment. The clay fines are transported to authorized storage facilities. This technology allows for the emptying of the tailing ponds, which will make them reusable for the same purposes they have been created for in the near future on one hand, and for adding economic value to this secondary source of energetic fuel on the other. [ABSTRACT FROM AUTHOR] |
