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PL
W artykule przedstawiono analizę zagadnienia przenoszenia skali na przykładzie jednego z typów krystalizatora powszechnie stosowanego w aplikacjach przemysłowych. Zdefiniowano istotny parametr procesowym, mający duży wpływ na powtarzalność technologii. Określono wymagania z punktu widzenia kinetyki procesu podczas przenoszenia skali oraz, biorąc pod uwagę najczęściej stosowaną procedurę, przeanalizowano możliwości i ograniczenia tego sposobu.
EN
The paper deals with scale-up problems. The issue is discussed in the light of draft tube magma crystallizer, commonly used in crystallization processes from solution. Authors defined the parameters mainly affecting the crystallization and product requirements during scale-up on one hand and on another consider, what can be done when the traditional procedure is applied.
PL
Przedstawiono sposób wydzielania struwitu MgNH4P04-6H20 ze ścieku z przemysłu nawozów fosforowych za pomocą jonów magnezu i amonu w krystalizatorze o działaniu ciągłym typu DTM ze strumienicą cieczową. Zaleca się prowadzenie procesu przy nadmiarze jonów magnezu, pil 9 i średnim czasie przebywania zawiesiny w krystalizatorze wynoszącym co najmniej dwie godziny. Wykazano, że z 1 m3h ścieku zawierającego 0,445% mas. jonów fosforanowych(V) można odzyskać do ok. 10 kg struwitu/h.
EN
Technology of struvite MgNH4P04-6H20 production from phosphorus mineral fertilizer industry liquid wastes with the use of magnesium and ammonium ions in a continuous DTM type crystallizcr with liquid jet pump was presented. It is recommended to carry out the proccss at magnesium ions excess, pH 9 and mean residence time of suspension in a crystallizcr at least two hours. It was demonstrated, that from 1 m3/h of liquid wastes containing 0.445 mass % of phosphatc(V) ions it is possible to rccovcr up to ca. 10 kg staivite/h.
EN
Reaction-crystallization processes of hydroxyapatite precipitation from its diluted water solutions in the DTM-type crystallizers were discussed. A liquid jet-pump, working with an assumed minimal power of the feeding stream, was tested. It was concluded that the product crystal agglomerates within the 76-316 žm size range were obtained. It was observed that with the increase of Ca2+ ions concentration in a feeding solution the agglomeration phenomena are more pronounced, while the increase of the temperature and the enlargement of suspension residence time effectively restrain the agglomeration effects.
EN
The influence of a mixing chamber length, feeding nozzle diameter, density and porosity of suspension on the required minimal value of unit power of the jet-pump feeding stream, providing stable circulation of suspension in a DTM type crystallizer, was presented. and defected seeds are moved to the surface by occluded air bubbles.
EN
The reaction-crystallization process of struvite precipitation from diluted water solutions of magnesium, ammonium and phosphate ions in a DTM type crystallizer with the jet-pump, working at the assumed minimal value of feeding stream unit power was discussed. Struvite crystals of a mean size within the range of 12—20 μm were produced. Process kinetic parameters were estimated on the basis of the product-crystals population density distribution.
EN
The reaction-crystallization process of hydroxyapatite precipitation from its diluted water solutions in a DTM type crystallizer equipped with the jet-pump working under the assumption of minimal power of a jet-pump feeding stream was discussed. It was concluded that crystal agglomerates with a size range of 227-285 mm were obtained.
EN
The research results concerning the reaction crystallization processes of hydroxyapatite (HAP) and struvite (MAP) in the two flow jet pump DTM crystallizers with the internal circulation of the suspension are presented. Calcium or/and magnesium ions precipitation from the diluted water solutions was taken into effect by the addition of ammonium dihydrogenphosphate NH4H2PO4 solution in the alkali environment (T = 298 K, pH = 9, t = 900 s). The influence of calcium (0.1 - 1.5 mass %) and magnesium (0.1 - 2.0 mass %) ions concentration in the feeding stream on the resulting product crystal size distribution was investigated. The test results can be utilized in the improvement of the jet pump DTM crystallizers design. This construction is especially recommended for the precipitation of the calcium or/and magnesium ions, as well as the phosphate(V) ions from the diluted solutions or the liquid wastes.
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