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Abstract  

Stability of mineral mixed fertilizers processed by effective mixing and compaction, using extrusion technology, is a subject of this study. As new products there is a need to learn the possible changes in the phase ratios and caking processes during long term storage. 7 samples with different nutrient components ratios are investigated after one year kept in a storage facility without conditioning. Applying TG-DTA, electron microscopy and X-ray diffraction methods samples are studied, recording thermal effects and mass losses, type of crystal structures and phase content in the sample. On the base of the results obtained the relationships are discussed and conclusions made about the possibility to safety storage and visible application of the new products as fertilizers in the agriculture for nut ratio of different plant. It is confirmed that the investigated samples, produced on the base of low grade phosphates are stable during long term storage and they could be successfully recommended for practical use in agriculture, using traditional or individual method of fertilization.

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Influence of thermal and thermo-mechanical treatment

Comparison of two lipids with respect to their suitability for solid lipid extrusion

Journal of Thermal Analysis and Calorimetry
Authors: Claudia Reitz and P. Kleinebudde

Abstract  

Two lipids with similar melting ranges but of different composition were analyzed using differential scanning calorimetry and X-ray diffraction. The lipids were processed via extrusion or were tempered at different temperatures; they were analyzed directly after extrusion and after storage at 40�C. Precirol ATO 5� showed high sensitivity to storage time and varied temperature exposure. Extrusion showed only marginal influences on the solid state. Melting peaks were narrower and shifted to higher temperatures in comparison to the untreated powder. Dynasan 114� was more robust, changes in the solid state could only be shown for samples treated above the melting range. Thus, Dynasan 114� is more appropriate for solid lipid extrusion of pharmaceutical products.

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Abstract  

It has been established that the coexistence of chemical species structurally different from cerium, is a direct consequence of the time taken for its preparation. Its practical applications, within the scope of purifying uranium, may constitute the most important technological aspect in the process of ionic exchange, to separate141Ce from uranium.

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Abstract  

Phosphate rocks were leached with hydrochloric acid; and radium was removed by co-precipitation with BaSO4. Uranium and lanthanides were extracted by di(2-ethyl hexyl) phosphoric acid and tributyl phosphate. Phosphoric acid was then separated from calcium chloride solution and other impurities by extraction using undiluted iso-amyl alcohol. Gypsum was precipitated by sulfuric acid to regenerate hydrochloric acid for recycling. Fluorine was precipitated from the initial leach solution as Na2SiF6.

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A megengedett határértéket meghaladó fémtartalmú városi szennyvíziszapnak a kísérleti talajok (savanyú és karbonátos homok, ill. savanyú agyagos vályog és karbonátos vályog) Co, Ni, Mn, Cu és Zn frakcióira (mobilis: 1 M NH 4 NO 3 -oldható, mobilizálható: ammónium-acetát+EDTA-oldható, „összes”: cc. HNO 3 +cc. H 2 O 2 roncsolás) és a tavaszi árpa szemtermésének elemtartalmára gyakorolt hatását vizsgáltuk tenyészedény-kísérletben. Az alkalmazott iszapterhelések a következők voltak: 0, 2,5, 5, 10 és 20 g iszap szárazanyag/kg légszáraz talaj. Az 5 iszapkezelés×4 talaj = 20 kezelés×4 ismétlés = 80 edényszámot tett ki. A kapott eredményeket az alábbiakban foglaljuk össze: – A talaj elemfrakciói és az árpaszem elemtartalma között regresszió-analízist végezve megállapítottuk, hogy az árpaszem és a talaj Co-, Ni-, Cu- és Zn-tartalmának kapcsolatát legjobban ezen elemek mobilis frakciójával jellemezhetjük. – Az iszappal kijuttatott elemek elenyésző hányada jelenik csak meg mobilis formában a talajban. Az eredmények azt mutatták, hogy minél gazdagabb a talaj a vizsgált elemekben, annál kisebb hányaduk van mobilis formában. A legnagyobb arányban a kijuttatott nikkel jelent mobilis elemként, átlagosan 3%-ban. A vizsgált elemek a Co és Mn kivételével a legnagyobb arányban a két homoktalajon, elsősorban a savanyú homokon voltak a mobilis frakcióban. A nyírlugosi talajon a legkisebb terheléssel kijuttatott Zn 19%-ban NH 4 NO 3 -oldható formában jelent meg. – A vizsgált elemek sorrendje a talajokon való megkötődés erőssége szerint a következő volt az adott kísérleti feltételek mellett: Mn > Zn > Cu > Ni = Co. – Az iszap pH-növelő hatásának eredményeképpen a vizsgált savanyú homoktalaj mobilis Co- és Mn-tartalma harmadára csökkent annak ellenére, hogy az „összes” elemtartalom nem változott szignifikánsan. Ez a csökkenés az árpaszem Co- és Mn-tartalmában is megmutatkozott. Ezért az iszapok szabadföldre történő elhelyezésénél az iszap elemtartalmán túl figyelembe kell venni egyéb paramétereit (pH, CaCO 3 %, szerves anyag) is, mert azok a talaj tulajdonságait és ezen keresztül a szennyező elemek oldódását befolyásolhatják. A fenti megállapítások megnyugtatóak a szennyvíziszapok mezőgazdasági hasznosítása szempontjából, de miután a kísérleti eredményeket extrém elemterhelés mellett kaptuk, hasonló munka elvégzése javasolható megengedett elemkoncentrációjú szennyvíziszappal is.

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The choice of an appropriate and safe disposal alternative should be based on the wide range of physicochemical examination thermal analysis in conjunction with other data enables identification of wastes, allows determination of weight losses at any stage of thermal decomposition and characterization of the combustible properties of wastes.

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Abstract  

The dynamics of SO2 emission during thermooxidation of Estonian oil shale, its semicoke, different samples of coal and their mixtures, as well as the influence of Estonian oil shale ash addition (for modelling the CFBC process) on the dynamics were studied. The experiments were carried out with thermogravimetric equipment under dynamic heating conditions (5 K min-1) in the atmosphere of dried air, with simultaneous gastitrimetric EGA. It was established that SO2 emission from the fuels started at 200-320C. Depending on the form of sulphur (organic, pyritic, sulphate), the emission took place in two or three steps, and continued up to 580-650C, during which 35-75% of the total sulphur was emitted into the gaseous phase. Regulating the mole ratio of free CaO/S in the mixtures of fuels with oil shale ash addition the emission of SO2 ceased abruptly at 460-540C and it was limited to the level of 7-30%.

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Abstract  

Additional1 bifunctional anion-exchange resins have been designed, synthesized and evaluated for their ability to take up Pu(IV) from nitric acid solutions. Bifunctionality is achieved by adding a second anion-exchange site to the pyridine nitrogen (also an anion-exchange site) of the base poly(4-vinylpyridine) resin. Previous work focused on the effect of varying the chemical properties of the added site along with the length of an alkylene ‘spacer’ between the two sites. Here we examine four new 3- and 4-picolyl derivatives which maintain more rigidly defined geometries between the two nitrogen cationic sites. These materials, which have the two anion-exchange sites separated by three and four carbons, respectively, exhibit lower overall Pu(IV) distribution coefficients than the corresponding N-alkylenepyridium derivatieves with more flexible spacers. Methylation of the second pyridium site results in a ca. 20% increase in the Pu(IV) distribution coefficients.

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