Sekundarni postupci smanjenja emisije oksida azota u procesu topljenja stakla

In this paper the new methods for reduction of NOx emission from glass melting furnaces were presented. The secondary measures are focused on development of different methods for elimination of nitrogen oxide from the smoke gasses. The main characteristics of the selective catalytic reduction process (SCR), selective non catalytic reduction process (SNCR) and 3R process were presented and some advantages and limitations of these processes were analyzed.U ovom radu su prikazani novi postupci smanjenja emisije NOx iz peći za topljenje stakla. Zbog visokih temperatura do kojih se zagreva vazduh neophodan za sagorevanje dolazi do visoke emisije oksida NOx iz staklarskih peći. Sekundarne mere usmerene su na razvoj postupaka za uklanjanje azotnih oksida iz dimnih gasova. Dat je prikaz selektivno nekatalitičkog, selektivno katalitičkog redukcionog i 3R postupka kao i njihove prednosti i nedostaci

Dissolution behavior of a polyphosphate glass into an aqueous solution under static leaching conditions

The dissolution behavior of a polyphosphate glass with a molar ratio [M2O + MO]/P2O5 gt 1 in distilled water under static condition was studied. The leaching tests were performed with glass powder samples (0.1-0.65 mm) at T=15-50 degrees C for times up to 720 h. The mass loss of the samples, the changes of pH and the concentration of elements (P, K, Ca, Mg, Zn and Mn) in solution were determined. The effects of temperature, time and particle size were analyzed. The results of the tests showed a complex dissolution behavior of this glass. The selective dissolution of the glass components was determined. The mechanism of formation and the structure of dissolved glass layer were investigated. The effects of cations on the mechanisms and kinetics of dissolution of the polyphosphate glass are presented. The activation energy of dissolution, Ea, was determined to be 39 +/- 5 kJ/mol

Crystallization behaviour of Li2O·Nb2O5·SiO2 glass containing TiO2

This paper deals with the crystallization of glass 30Li2O·15Nb2O5·50SiO2·5TiO2 (mol%). The crystallization behavior was studied under isothermal and non-isothermal conditions. XRD and SEM methods were employed for determination of phase composition and microstructure of crystallized glass. It was detected that this glass crystallizes by the surface crystallization mechanism. SEM micrographs of the crystallized samples revealed that the crystals grow in the form of dendrites. The glass-ceramics with complex phase composition was obtained. Three crystalline phases were detected where LiNbO3 has grown as primary phase and a secondary ones Li2Si2O5 and SiO2 appeared. The calculated average crystallite sizes are: 27 nm for LiNbO3 , 115 nm for Li2Si2O5 and 45 nm for SiO2 . From the experimental data an activation energy of crystals growth, calculated using the Kissinger relation, is Ea = 275 ±10 KJ / mol

Mere i metode za smanjenja emisije oksida azota iz peći za topljenje stakla

The nitrogen oxides emitted to atmosphere effect significantly on formation of photochemical smog, acidic rains and destroying of ozone shell of the earth. Therefore, the regulations for limited emission of nitrogen oxides to atmosphere become very strict. Glass manufacturing is a high-temperature, energy-intensive activity, because of the high temperature NOx emissions are extremely high. NOx emissions could be reduced by primary process modifications measures end secondary post-combustion measures. Primary process modifications are usually based on the following techniques: stoichiometric combustion and advanced burners systems, staged combustion (air- or fuelstaged), recircylation of flue gasses.Razvojem tehnike i tehnologije javlja se potreba za većom proizvodnjom energije. Iako se danas uvode u upotrebu i drugi izvori energije, još uvek je najzastupljenije dobijanje energije u procesu sagorevanja goriva. Zbog visokih temperatura koje nastaju pri sagorevanje dolazi do velike emisije NOx oksida. U ovom radu opisane su mere i metode kojima je moguće smanjiti emisiju NOx u procesima dobijanja stakla

Crystallization behaviour of Li2O·Nb2O5·SiO2 glass containing TiO2

This paper deals with the crystallization of glass 30Li2O·15Nb2O5·50SiO2·5TiO2 (mol%). The crystallization behaviour was studied under isothermal and non-isothermal conditions. XRD and SEM methods were employed for determination of phase composition and microstructure of crystallized glass. It was detected that this glass crystallizes by the surface crystallization mechanism. SEM micrographs of the crystallized samples revealed that the crystals grow in the form of dendrites. The glass-ceramics with complex phase composition was obtained. Three crystalline phases were detected where LiNbO3grown as primary phase and a secondary ones Li2Si2O5 and SiO2 appeared. The calculated average crystallite sizes are: 27 nm for LiNbO3, 115 nm for Li2Si2O5 and 45 nm for SiO2. From the experimental data an activation energy of crystals growth, calculated using the Kissinger relation, is Ea = 275 ±10 KJ / mol

Primena stakla sa kontrolisanim otpuštanjem hranljivih elemenata u proizvodnji rasada kadifice (Tagetes patula L.)

This paper investigates the possibility and justification of controlled release glass application as a new ecological material in the production of plants-seedlings of French marigold (Tagetes patula L.). During the investigation its influence on the development of the produced plants-seedlings was monitored. The seedlings were produced in poly-propylene containers (speedling system) and poly-propylene pots (pot system). The trial was conducted in the greenhouse at the Faculty of Agriculture in Belgrade during 2011. In the course of seedling production the glass granulation of lt 0.5 mm was added in the following doses: 0, 1, 2, 3, and 4 g/l. The results of the research show a positive effect of controlled release glass application in the production of French marigold seedlings, since high quality seedlings were produced justifying its application. The best effect on the analyzed parameters of plant-seedling development was found when substrate was applied in the dose of 1 g/l.U radu je ispitivana mogućnost i opravdanost primene stakla sa kontrolisanim otpuštanjem hranljivih elemenata kao novog ekološkog materijala u proizvodnji biljaka-rasada kadifice (Tagetes patula L.). Tokom istraživanja praćen je njegov uticaj na razvijenost proizvedenih biljaka-rasada. Biljke-rasada proizvedene su u polistirenskim kontejnerima (speedling system) i polipropilenskim saksijama (pot system). Istraživanja su sprovedena u stakleniku Poljoprivrednog fakulteta u Beogradu tokom 2011. U toku proizvodnje rasada dodavano je ispitivano staklo granulacije lt 0,5 mm u dozama 0-4 g/l. Rezultati istraživanja ukazuju na pozitivan efekat primenjenog stakla sa kontrolisanim otpuštanjem jona u proizvodnji biljaka-rasada kadifice. Njegovom primenom dobija se rasad bolje razvijenosti, te je njegova upotreba opravdana. Najbolji efekat na ispitivane parametre razvijenosti biljaka-rasada imala je doza od 1 g/l supstrata