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1

Process Optimization for the Gas-Liquid Heterogeneous Reactive Crystallization Process Involved in the Preparation of the Insensitive High Explosive TATB

Nandi A. K., Kshirsagar A. S., Thanigaivelan U., Bhattacharyya S. C., Mandal A. K., Pandey R. K., Bhattacharya B.

Central European Journal of Energetic Materials

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2014

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Vol. 11, no. 1

31--57

EN

The thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6- trinitrobenzene (TATB) is manufactured by amination of 1,3,5-trichloro-2,4,6- trinitrobenzene (TCTNB) in toluene with NH3 gas. It is an isothermal, single-feed, semi-batch, gas-liquid heterogeneous, reaction crystallization process. The amination process is discussed by applying the chemical engineering methodology of mass transfer and reactive crystallization processes based on Two-Film Mass- Transfer (TFMT) theory. Kinetic expressions have been developed to define the chemical reactions as well as the physical phenomena (mass transfer) associated with this process. A single expression has been derived to explain the dependence of the ammonia consumption rate on various process parameters. Subsequently, the influence of various process parameters on the product quality (particle size and chloride impurity content) has been studied on the laboratory scale. Finally, the process has been established in the pilot plant, with optimized process conditions, to realize TATB of desired particle size and chloride content. The effects of feeding excess ammonia, and the presence of mercaptans/hydrogen sulphide impurities in poor quality toluene on the formation of certain undesirable by-products in TATB, are also discussed.

2

Reaction crystallization of struvite in a continuous DTM type crystallizer with a compressed air driven jet pump

Matynia A., Mazieńczuk A., Piotrowski K., Wierzbowska B., Hutnik N., Kozik A.

Polish Journal of Chemical Technology

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2011

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Vol. 13, nr 2

46-53

EN

Experimental tests covering the production of struvite MgNH4PO4ź6H2O from water solutions containing 1.0 mass % of phosphate(V) ions using magnesium and ammonium ions in stoichiometric proportions were carried out in a crystallizer of 1.2 dm3 working volume. The process temperature was 298 K. Struvite crystals of mean size Lm from ca. 14 to ca. 38 µm were produced depending on the process environment's pH (9-11) and the mean residence time of suspension in a crystallizer, τ (900-3600 s). In such defined process conditions the linear growth rate of struvite crystals changed from 1.45ź10-8 m/s (pH 9, τ 900 s) to 2.06ź10-9 m/s (pH 11, τ 3600 s) while the nucleation rate from 5.1ź10^7 to 3.2ź10^9 1/(sm3). Crystal product of the most advantageous granular characteristics was produced at pH 9 and the mean residence time 3600 s. Within this product population the largest sizes reached above 200 µm while the number of crystals smaller than 3 mm was kept below 6%.

3

Odzyskiwanie jonów fosforanowych(V) z roztworów odpadowych zawierających zanieczyszczenia organiczne

Kozik A., Hutnik N., Matynia A., Gluzińska J., Piotrowski K.

Chemik

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2011

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Vol. 65, nr 7

675-686

PL

Wydzielano w sposób ciągły struwit z wodnego roztworu zawierającego jony fosforanowe (0,20% mas.), magnezu i amonu w proporcjach stechiometrycznych i kwas mlekowy (0,03 lub 0,06% mas.). Proces prowadzono w temperaturze 298K w krystalizatorze typu DT MSMPR z wewnętrzną cyrkulacją zawiesiny. Przebadano wpływ pH (od 8,5 do 10) i średniego czasu przebywania zawiesiny w krystalizatorze (od 900 do 3600 s) na rozkład rozmiarów kryształów produktu, ich jednorodność i kształt, oraz na kinetykę zarodkowania i wzrostu kryształów struwitu. W badanym zakresie parametrów procesowych otrzymano kryształy produktu o średnim rozmiarze od 28,6 do 80,0 mm o zróżnicowanym pokroju i jednorodności. Ich liniowa szybkość wzrostu wynosiła od 7,68?10-9 do 2,29?10-8 m/s. Najlepiej wykształcone kryształy, o typowym dla struwitu kształcie i pożądanej jednorodności otrzymano w zakresie pH 8,5 x9 i wydłużonym średnim czasie przebywania 3600 s. W tak zdefiniowanych warunkach kwas mlekowy, symulujący obecność substancji organicznych w rozcieńczonym wodnym roztworze fosforanów(V), ogólnie korzystnie oddziaływał na przebieg i rezultaty badanego procesu.

EN

Struvite was continuously produced from water solutions containing phosphate(V) ions (0.20 mass %), magnesium and ammonium ions in stoichiometric proportions, as well as lactic acid (0.03 or 0.06 mass %). Reaction crystallization of struvite was carried out in temperature 298 K in DT MSMPR type crystallizer with internal circulation of suspension. Influence of pH (from 8.5 to 10) and mean residence time of suspension in the crystallizer (from 900 to 3600 s) on product crystal size distributions, crystal phase homogeneity and shape, as well as on struvite nucleation and crystal phase growth kinetics was identified. Within the process parameter ranges tested product crystals of mean size from 28.6 to 80.0 mm, of diversified habit and size homogeneity were reported. Their linear growth rate varied from 7.68x10-9 to 2.29x10-8 m/s. The best crystals, of typical for struvite shape and required homogeneity were produced at pH 8.5 - 9 and for elongated mean residence time 3600 s. In such defined process conditions lactic acid, simulating presence of organic substance load in diluted water solution of phosphates(V), influenced course and final results of the investigated process advantageously.

4

Wytrącanie i krystalizacja struwitu w obecności jonów żelaza(III)

Hutnik N., Matynia A., Wierzbowska B.

Chemik

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2010

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Vol. 64, nr 12

816-823

PL

Przedstawiono wyniki badań dotyczących ciągłego wydzielania struwitu za pomocą jonów magnezu i amonu w warunkach stechiometrycznych z roztworów wodnych zawierających 1,0% mas. jonów fosforanowych(V) i jony żelaza(III). w zależności od stężenia tych jonów (1 ÷ 10 mg Fe3+ / kg roztworu), pH (9 ÷ 11) i średniego czasu przebywania zawiesiny w krystalizatorze (900 ÷ 3600 s) otrzymano produkty o średnim rozmiarze kryształów od 20 do 43 žm. wykazano, że jony żelaza(III) niekorzystnie oddziaływują na rozmiary kryształów struwitu (L m ok. 36 › 26 žm) i jednorodność ich populacji (CV = 71 › 97%). wytrącone z kryształami struwitu cząstki wodorotlenku żelaza(III), o rozmiarach często poniżej 1 žm, tworzyły aglomeraty, również na powierzchni kryształów struwitu. Obecność jonów żelaza(III) przyczyniła się do krystalizacji struwitu w postaci kryształów rurowych.

EN

The experimental results concerning continuous reaction crystallization of struvite from water solutions containing 1.0 mass % of phosphate(V) and iron(III) ions with magnesium and ammonium ions in stoichiometric conditions are presented. Depending on foreign ion concentration (1 ÷ 10 mg Fe3+ /kg of solution), pH (9 ÷ 11) and mean residence time of suspension in crystallizer (900 ÷ 3600 s) the crystal products of mean crystal size from 20 to 43 žm were obtained. It was proved that iron(III) ions affect struvite crystal sizes (L m ca. 36 › 26 žm) and their population homogeneity (CV = 71 › 97%) disadvantageously. The iron(III) hydroxide particles co-precipitated with struvite crystals, usually of size below 1 žm, formed agglomerates - also on the parent struvite crystal surfaces. Presence of iron(III) ions contributes struvite crystallization in characteristic tubular-shape form.

5

Experimental and Modeling Study on Precipitation Kinetics of Silver in Nano and Micron Scale

Manteghian M., Ghader S.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 4

625-639

EN

In the present study, reaction crystallization of silver micron and nanoparticles was studied in a batch crystallizer in two different set of experiments by reducing silver in the presence or absence of sodium citrate. From the experimental determination of crystalsize distribution, and with the aid of a mathematical model of the process, nucleation and growth kinetics of silver nanoparticles were de termined. Kinetic parameters were determined by fitting the power law expression to the experimental data. Nanoparticle growth rates indicate a diffusion controlled mechanism with a first order dependence on supersaturation, while the observed low dependence of nucleation rate on magma density imply the primary nucleation occurring. Never the less, in the synthesis of micron particles magma density was important and agglomeration took place and nucleation, volume crystal growth rates as well as agglomeration kernel were determined.

6

Wpływ jonów glinu na jakość kryształów struwitu wydzielanego w sposób ciągły z roztworów rozcieńczonych

Hutnik N., Wierzbowska B., Matynia A., Piotrowski K., Gluzińska J.

Chemik

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2008

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Vol. 61, nr 10

505-508

PL

Przedstawiono wyniki badań dotyczących usuwania jonów fosforanowych z roztworów rozcieńczonych (0,977% mas. PO43-) za pomocą jonów magnezu i amonu w warunkach stechiometrycznych w obecności jonów glinu w krystalizatorze DT MSMPR o działaniu ciągłym. Proces strącania i krystalizacji struwitu prowadzono z roztworów zawierających 0,001-0,02% mas. Al3+. Określono doświadczalnie wpływ stężenia jonów glinu na rozkład rozmiarów otrzymanych kryształów struwitu oraz na składy chemiczne roztworu macierzystego i produktu (m.in. dystrybucja jonów Al3+ pomiędzy fazę stałą i ciekłą). Wykazano, że jony glinu korzystnie oddziaływują na rozmiary kryształów struwitu (Lm ok. 32 → 42 µm) jak też na jednorodność populacji (CV = 86 → 75%). W produkcie krystalicznym (struwit) stwierdzono obecność jonów Al3+ w postaci cząstek wodorotlenku glinu, zarówno indywidualnych jak i zaglomerowanych powierzchniowo na dużych kryształach struwitu.

EN

The experimental results concerning removal of phosphate ions from the diluted solutions (0,977 mass % PO43-) by means of magnesium and ammonium ions applied in stoichiometric proportions in the presence of aluminum ions in a continuous DT MSMPR crystallizer are presented. Reaction crystallization of struvite was carried out using the mixtures containing 0,001 - 0,02 mass % of Al3+ ions. Influence of aluminum ions on the crystal size distribution of struvite, as well as chemical compositions of mother solution and crystal product (distribution of Al3+ ions among the liquid and solid phases) were determined experimentally. Advantageous influence of Al3+ ions on the enlargement of mean crystal size of struvite (Lm ca. 32 → 42 µm) and on the increase in its population homogeneity (CV = ca. 86 → 75%) was confirmed. Presence of Al3+ ions in a form of Al(OH)3 particles in a main crystal product (struvite), both as the individual ones and in a form of surface agglomerates, was detected.

7

The influence of the process parameters on the hydroxyapatite continuous crystallization kinetics

Matynia A., Koralewska J., Piotrowski K.

Polish Journal of Chemical Technology

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2005

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Vol. 7, nr 1

44-53

EN

The results of the mass crystallization kinetics of the process of calcium ions precipitation with the use of ammonium dihydrogenphosphate NH4H2PO4 in water under alkaline conditions (pH = 9) are presented. The experiments were carried out in the continuous laboratory DTB MSMPR (Draft Tube Baffle, Mixed Suspension Mixed Product Removal) crystallizer with the internal circulation of the suspension. The influence of calcium ions concentration in the feed stream, the temperature and the residence time on the nucleation and the growth rates of hydroxyapatite crystals formed, was established. The kinetic parameters were evaluated from the crystal size distributions employing selected SDG (Size Dependent Growth) models.

8

Jet pump crystallizers in the reaction crystallization processes of sparingly soluble salts

Matynia A., Koralewska J., Wierzbowska B., Piotrowski K.

Polish Journal of Chemical Technology

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2005

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Vol. 7, nr 3

56-63

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.

9

Krystalizacja masowa KHCO3 w procesie karbonizacji katolitu z elektrolizy wodnego roztworu chlorku potasu

Lemanowska E., Buczkowski R., Igliński B

Inżynieria i Aparatura Chemiczna

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2004

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Nr 4-5

31-33

PL

W pracy przedstawiono opis krystalizacji masowej wodorowęglanu potasu w procesie karbonizacji katolitu z elektrolizy wodnego roztworu chlorku potasu w oparciu o analizę rozkładu rozmiarów kryształów. Sporządzono histogramy unormowanego rozkładu liczbowego kryształów KHCO33 zawiesiny). Zaproponowano metodę produkcji potażu z roztworów po elektrolizie chlorku potasu.

EN

This work describes mass crystallization of potassium bicarbonate in the carbonization process of catholyte from the electrolysis of potassium chloride solution on the basis of crystal size distribution analysis. Histograms of the normalized numbers distribution of KHCO3 crystals have been prepared and the relationship Mi o = f (t) (where: Mi o - number of crystals in 1m3 suspension) has been presented. The method of potash production from solution after electrolysis of potassium chloride has been proposed.