Alternative Soda-Lime Glass Batch to Reduce Energy Consumption

2013 ◽  
Vol 545 ◽  
pp. 24-30 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Kanit Tapasa ◽  
Tepiwan Jitwatcharakomol

Soda-lime glass is produced by melting sand (SiO2), soda ash (Na2CO3), lime stone (CaCO3) together with effective additives such as dolomite (CaMg(CO3)2) and an important structural modification, alumina (Al2O3) in which the melting temperature is very high around 1500°C. With this reason, to dissolve alumina, high amount of energy is needed. Consequently, one of possibilities to reduce the melting energy is replacing alumina by the raw material with a lower enthalpy of melting. The heat required for melting the batch of raw materials from atmosphere temperature to melting temperature is called exploited heat (Hex), which can be calculated from chemical enthalpy (H°chem) and heat content (Hmelt) at reference temperature (Tex). From thermodynamic approach, chemical enthalpy of alumina is higher than feldspar (KAlSiO3) or pyrophyllite (Al2Si4O10(OH)2). For the glass batch with alumina, the calculated exploited heat is 540 kWh/ton while the batch with feldspar or pyrophyllite is lower, namely 534 and 484 kWh/ton, respectively. This means that the melting process can be emerged easier than the batch with alumina because the melting point of feldspar is around 1200°C and pyrophyllite dehydroxylates around 900°C. The kinetic properties of batch melting were investigated by Batch-Free Time method, which defines the melting ability of the modified batch. According to thermodynamic calculation, it was found that both alternative batches were melted easier. The study showed that feldspar or pyrophyllite could be used instead of alumina without significant changes in glass chemical composition and physical properties. The concern of using feldspar or pyrophyllite is the quantity of minor impurities which affect to the color appearance especially in clear glass products.

2016 ◽  
Vol 690 ◽  
pp. 272-275
Author(s):  
Kanit Tapasa ◽  
Ekarat Meechoowas ◽  
Suwannee Thepbutdee ◽  
Amorntep Montreeuppathumb

In the conventional soda-lime glass production, loose raw materials are normally mixed into a glass batch for melting. Dusting and segregation of the loose glass batch are always occurred during the melting process inside the glass furnace. Also, the loose glass batch has low thermal conductivity which limits the glass melting ability and pulling rate of the glass furnace. Granulation and preheating of glass raw materials have been proposed to solve the problems. In this study, the granulated soda-lime glass batch (SiO2 50% Na2CO3 22.5% CaCO3 12% NaAlSi3O8 9.5% BaCO3 2.5% ZnO 1.75% Sb2O3 1% and K2CO3 0.75% by weight) was prepared to study the melting ability in an electric furnace. The granulated batch was also preheated at 500-600°C before melting. The preheating temperature was matched to the temperature of flue gas at the bottom of the stack in the glass furnace. The purpose behind this was aiming to recover the waste heat from the furnace. The experiment exhibited the increased melting ability for the granulated-preheated glass batch


2014 ◽  
Vol 608 ◽  
pp. 311-315 ◽  
Author(s):  
Kanit Tapasa ◽  
Ekarat Meechoowas ◽  
Usuma Naknikham ◽  
Tepiwan Jitwatcharakomol

Batch modification with low-enthalpy raw materials is the effective approach for reducing the glass melting energy. In the previous study, it was found that introducing wollastonite (CaSiO3) as a source of CaO instead of calcium carbonate (CaCO3) in the soda-lime glass batch can fasten the melting process. It is because the modified batch with CaSiO3 has lower chemical heat demand, ΔHochem, which is equivalent to the standard heat of batch-to-melt conversion. In order to investigate the kinetic property of the modified batch, the melting behaviour of 2 kg modified batch was studied. The results showed that the temperature of the modified batch increased at a faster rate than the original batch. The properties of the glass from the modified are also similar to the original batch.


2013 ◽  
Vol 770 ◽  
pp. 128-131 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Konnika Tui-Ai ◽  
Kanit Tapasa ◽  
Usuma Naknikham ◽  
Tepiwan Jitwatcharakomol

The soda-lime glass with the composition of 74SiO2-18Na2O-6CaO-B2O3-Al2O3 thermodynamically requires the exploited heat of 557 kW/ ton of glass to transform raw materials into glass. The objective of this project is to modify the soda-lime glass batch by using wollastonite instead of limestone and pyrophyllite instead of aluminium hydroxide. The exploited heat of the batch with wollastonite is reduced to 546 kW/ton of glass while the batch with wollastonite and pyrophyllite is decreased to 550 kW/ton of glass. According to Batch-Free Time testing, it is found that the melting ability of both modified batches is higher than of the original batch, while the properties of glass are slightly changed. This implies that the modified batch requires a lower melting energy than the original batch.


2019 ◽  
Vol 138 (6) ◽  
pp. 4571-4583
Author(s):  
Anna A. Kuśnierz ◽  
Magdalena Szumera ◽  
Magda Kosmal ◽  
Paweł Pichniarczyk

Abstract A glass set with a high content of blast-furnace slag and a reduced amount of traditional raw materials requires optimization of the raw material composition and adjustment of its specificity to the temperature regime of melting, homogenizing and clarifying the glass mass. The introduction of an increased amount of blast-furnace slag allows to reduce the cost of raw materials: soda, limestone and high-class sand, reduce energy costs, whose consumption significantly decreases and reduces CO2 emissions in line with EU requirements. The tests of thermal analysis of a glass set with different contents of Calumite are aimed at learning the mechanism of its operation by determining the changes caused by its different presence in the course of subsequent reactions between the components of the glass set. Analysis of the influence of the addition of different Calumite slag contents treated as a substitute for the raw material on the melting process of glassware sets was analyzed. The tests were carried out using differential thermal analysis (DTA) and thermogravimetry (TG) based on the model glass [mass%]: 73.0% SiO2, 1.0% Al2O3, 10.0% CaO, 2.0% MgO and 14.0% Na2O. The effect of combining Calumite with sulphate and multi-component fining agent—mixtures of As2O3, Sb2O3, NaNO3 in proportions of 1:1:1 for chemical reaction and phase transformation, was investigated.


Ceramics ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 1-11
Author(s):  
Patricia Rabelo Monich ◽  
Hugo Lucas ◽  
Bernd Friedrich ◽  
Enrico Bernardo

Material from the electric arc furnace smelting of municipal solid waste incineration (MSWI) bottom ash was easily converted into highly porous glass-ceramics by a combination of inorganic gel casting and sinter-crystallization at 1000 °C. In particular, the gelation of aqueous suspensions of fine glass powders, transformed into “green” foams by intensive mechanical stirring, occurred with a limited addition of alkali activator (1 M NaOH). The products coupled the stabilization of pollutants with good mechanical properties (e.g., compressive strength approaching 4 MPa). Interestingly, they could be used also as raw material for new glass-ceramic foams, obtained by the same gel casting and sintering method, with no degradation of chemical stability. Limitations in the crushing strength, derived from the limited viscous flow densification of semi-crystalline powders, were overcome by mixing powders from recycled foams with 30 wt% soda-lime glass. The new products finally featured an even higher strength-to-density ratio than the foams from the first cycle.


2020 ◽  
Vol 269 ◽  
pp. 127579
Author(s):  
Vinicius Rodrigues Gomes ◽  
Michelle Pereira Babisk ◽  
Carlos Maurício Fontes Vieira ◽  
Juraci Aparecido Sampaio ◽  
Francisco Wilson Hollanda Vidal ◽  
...  

2019 ◽  
Vol 798 ◽  
pp. 206-211
Author(s):  
Ekarat Meechoowas ◽  
Parida Jampeerung ◽  
Kanit Tapasa ◽  
Usanee Pantulap ◽  
Tepiwan Jitwatcharakomol

The soda bloom - white stain on the glass surface – is an issue concerned in the glass manufacturing. It is because of high humidity and warm weather especially in the tropical region. The aim of this study was to modify glass batch to increase the weathering resistance for soda-lime glass. The weathering resistance of glass was measured by using the sodium (Na) leach technique according to the ISO 719. In principle, the strength of glass structure decreases with increasing Na content. The reactions start when free Na+ions moving to the glass surface and react with moisture from the surroundings. From this reason, the soda bloom occurs during storage lifetime. Two samples of glasses as described in Table 1 were modified with dolomite (CaMg (CO3)2) or alumina (Al2O3) to reduce the sodium free ion on the glass surface and increase the strength of glass structure Table 1: The glasses compositions All glasses were melted at 1500oC for 3 hours and annealed at 570°C. In glass structure, magnesium (Mg) and aluminium (Al) are network modifiers that can improve the structural strength and the weathering resistance of glass. The weathering resistance is in the inverse relationship with the weight of Na2O in mg per 50 ml of water according to theISO 719. The results showed that the weathering resistance increased with increasing dolomite or alumina contents. The experiments of increasing dolomite from 0 to 18 wt.% in a replacement of calcite showed the result that indicated the weight of Na2O in mg per 50 ml of water decreased from 0.53 to 0.41 mg, and the glass with increasing alumina from 0 to 1 wt.% showed that the weight of Na2O in mg per 50 ml of water decreased from 0.80 to 0.39 mg. According to the weathering chamber test under the cyclic atmospheric conditions of 60% and 80% relative humidity, and the cyclic temperatures of 20°C and 32 °C for 14 days, the glasses with more than 12 wt.% dolomite or more than 1 wt.% alumina did not generate the white stains on the surface. This process can be applied in the glass production. The satisfied result was found in the glass sample with 12 wt.% dolomite and 1 wt.% alumina. The weight of Na2O per 50 ml H2O reduced to 0.43 and 0.41mg, respectively, and the storage time increased from 3 months to 6 months without soda bloom.


2018 ◽  
Vol 37 (6) ◽  
pp. 581-586 ◽  
Author(s):  
Jinxia Meng ◽  
Weiqing Chen ◽  
Jizeng Zhao ◽  
Li Liu

AbstractTo make use of chromium slag waste, this study examined the technology of the preparation of MgAl2O4 spinel refractory raw material by using chromium slag. The results showed that (1) using the traditional sintering process of synthetic spinel, the highest volume density was 3.14 g/cm3 and the lowest porosity rate was 9.16 %. With the increase of the proportion of MgO powder mixing, bulk density and porosity fluctuations, and which cannot meet the requirements of refractory raw materials. (2) For MgAl2O4 spinel prepared by the electric-melting process, the highest volume density was 3.27 g/cm3 and the lowest porosity rate was 8.78 %. Volume density and the porosity remained stable, and they are affected by MgO powder thus the blending ratio is very small, which can satisfy the requirements of refractory raw materials. (3) MgAl2O4 spinel prepared by the electric-melting method is superior to traditional MgAl2O4 spinel in terms of slag resistance and thermal shock resistance.


2012 ◽  
Vol 626 ◽  
pp. 1006-1009
Author(s):  
Hidayu Jamil Noorina ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Che Pa Faizul ◽  
Mohd Zaki Ruhiyuddin ◽  
Darus Murizam ◽  
...  

Oil Palm Ash is one of the abundance agricultural wastes found in Malaysia. This wastes need to be disposed properly. Oil palm ash contains compounds needed to produce glass. Most of raw materials (especially silica) used to produce existing commercial glass are imported; therefore it is the best time to highlight the potential of local natural waste as the raw material in glass production. In this study, raw material characterization, glass production and glass product evaluation has been done. A few parameters have been recognized to have effect on green glass production such as mixing compositions and firing temperature. Oil palm ash has been washed and dried then sieved to get uniformity of particle size. Then, oil palm ash is mixed with other glass materials such as alumina and flux and undergone melting process at 1400°C. Through the experiments, the best glass compositions are as follows: 80% palm ash, 10% kaolin and 10% feldspar or 10% dolomite while the suitable temperature being used for sintering process to produced end product is range between 1150°C to 1200°.


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