scholarly journals MICROWAVE MANUFACTURE OF GLASS FOAM BY COMBINED USE OF GRAPHITE AND CALCIUM CARBONATE AS FOAMING AGENTS

2021 ◽  
Vol 27 (1) ◽  
pp. 110-119
Author(s):  
LUCIAN PAUNESCU ◽  
SORIN MIRCEA AXINTE ◽  
MARIUS FLORIN DRAGOESCU ◽  
BOGDAN VALENTIN PAUNESCU ◽  
FELICIA COSMULESCU
Keyword(s):  
Calcium Carbonate ◽  
High Strength ◽  
Industrial Processes ◽  
Glass Waste ◽  
Foaming Agents ◽  
Combined Use ◽  
Variable Weight ◽  
Low Energy Consumption ◽  
Experimental Variant ◽  
Glass Foam

The paper presents experimental results obtained in the manufacturing process of high-strength glass foam by combined use of two solid foaming agents (calcium carbonate and graphite) in variable weight ratios. The originality of the work is applying the unconventional microwave heating method, unlike the conventional techniques currently used in similar industrial processes. The optimal experimental variant, composed of 89.1 % glass waste, 0.9% calcium carbonate, 1 % graphite and other additives, was sintered at 828 ºC with a very low energy consumption (0.73 kWh/kg). The main characteristics of the optimal product were apparent density of 0.39 g/cm3, thermal conductivity of 0.088 W/m·K and compressive strength of 3.6 MPa, being usable in fields that requires resistance to mechanical stress and relatively difficult environmental conditions.

scholarly journals New Manufacturing Method of Glass Foam by Cold Expansion of Glass Waste

2021 ◽  
Vol 2 (3) ◽  
pp. 1-9
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Bogdan Valentin Paunescu
Keyword(s):  
Thermal Conductivity ◽  
Aqueous Solution ◽  
Compressive Strength ◽  
High Temperature ◽  
Insulation Material ◽  
Glass Waste ◽  
Foaming Agents ◽  
Manufacturing Method ◽  
Aluminium Powder ◽  
Glass Foam

Abstract                                                         An innovation cold manufacturing method of glass foams is presented in the paper. Traditional foaming agents used in conventional expansion processes of glass waste at high temperature were substituted with aluminium powder in aqueous solution of calcium hydroxide, which releases hydrogen forming gas bubbles in the viscous sludge and then, by solidification, a porous structure typical for the glass foam. The manufactured foam is adequate for using as a thermal insulation material for inner wall of buildings, having the apparent density of 0.31 g·cm-3, the thermal conductivity of 0.070 W/m·K and the compressive strength of 1.32 MPa. The process originality is the use of recycled aluminum waste, melted by an own microwave heating technique and sprayed with nitrogen jets. The process effectiveness is remarkable in economical and energy terms.

scholarly journals Unconventionally Made-Cellular Glass Aggregate

2021 ◽  
Vol 2 (6) ◽  
pp. 21-31
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Felicia Cosmulescu
Keyword(s):  
Calcium Carbonate ◽  
Sodium Silicate ◽  
Electromagnetic Waves ◽  
Microwave Field ◽  
Industrial Processes ◽  
Sodium Borate ◽  
Residual Glass ◽  
Cellular Glass ◽  
Glass Aggregate ◽  
Fluxing Agent

Improving the original manufacturing process in microwave field of a cellular glass aggregate using a recipe containing colored consumed drinking bottle, calcium carbonate (CaCO3) as an expanding agent, sodium borate (borax) as a fluxing agent and sodium silicate (Na2SiO3) as a binder is shown in the work. The main adopted technological measures were the advanced mechanical processing of residual glass at a grain dimension below 100 μm and especially the use of a high electromagnetic wave susceptible ceramic tube with a wall thickness reduced from 3.5 to 2.5 mm for the protection of the pressed glass-based mixture against the aggressive effect of microwave field and, in the same time, to achieve a preponderantly direct heating with electromagnetic waves. Of the tested variants, a recipe with 1.6 % calcium carbonate, 6 % borax, 8 % sodium silicate and the rest residual glass was determined to be optimal. The cellular glass aggregate had the bulk density of 0.22 g/cm3, heat conductivity of 0.079 W/m·K and compression strength of 5.9 MPa. The specific consumption of energy was very low (0.71 kWh/kg) below the range of reported values of the industrial processes consumption (between 0.74-1.15 kWh/kg).  

scholarly journals Alternative foaming agents for fabrication of glass foam

2021 ◽  
Vol 11 (5) ◽  
pp. 39-48
Author(s):  
Ildikó Fóris ◽  
Gábor Mucsi
Keyword(s):  
Raw Materials ◽  
Powder Mixtures ◽  
Foaming Agent ◽  
Foaming Agents ◽  
Heat Treated ◽  
Specimen Density ◽  
Before And After ◽  
Different Temperatures ◽  
Glass Foam ◽  
Eggshell Waste

Glass foam tablets were produced from container glass bottles (CGB) using eggshell waste (ESW) and perlite (P) as foaming agent in different portions. The ground raw materials (CGB, ESW, P) were homogenized and pressed with hydraulic piston press machine at different pressures (in the case of P containing tablets 30 MPa and ESW containing tablets 15 MPa, 30 MPa and 40 MPa were used).The obtained glass tablets were heat treated at different temperatures (in the case of P containing tablets 800 °C, 900°C, 1000°C and 1100°C, and ESW containing tablets 600 °C, 700 °C, 800 °C and 900 °C were used). The study shows the specimen density of tablets before and after heat treatment, as well as the true density of the powder mixtures before tableting and the abrasion resistance of the glass foam products.

scholarly journals Some Properties of High Strength Sustainable Concrete Containing Glass Powder Waste

2018 ◽  
Vol 11 (2) ◽  
pp. 42-32
Author(s):  
Wasan I. Khalil ◽  
Nazar F. Al-Obeidy
Keyword(s):  
Modulus Of Elasticity ◽  
Electrochemical Techniques ◽  
Low Carbon Steel ◽  
High Strength ◽  
Partial Replacement ◽  
Low Carbon ◽  
Natural Pozzolan ◽  
Glass Waste ◽  
Sustainable Concrete ◽  
Glass Wastes

This investigation includes the use of glass wastes after recycling to produce high strength sustainable concrete. The glass waste used is prepared to be a natural Pozzolan class (N) according to ASTM C618 with fineness of about 7340 cm2/gm. Many concrete mixes with different percentages of glass waste powder as a partial replacement by weight of cement (10%, 15%, 20%, 25%, and 30%) were prepared to study some properties of concrete (compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity at 60 day age). The test results indicate that the mechanical properties of concrete are improved with the increase of glass waste powder up to 15%, and then decreased. The maximum percentages of increase for compressive, splitting tensile, flexural strengths, and modulus of elasticity are 13.29%, 36.27%, 34.68%, and 8.2% respectively relative to the reference for concrete specimens containing 15% glass waste powder as a replacement by weight of cement.Corrosion inhibition of low carbon steel, stainless steel types 316 and 304 in hydrochloric acid by potassium iodide was investigated at different temperatures using weight loss and polarization electrochemical techniques

Microstructural Control of 7075 Al Wrought Alloys through Thixoextrusion Route

2006 ◽  
Vol 510-511 ◽  
pp. 362-365 ◽  
Author(s):  
Young Ok Yoon ◽  
Hyung Ho Jo ◽  
Jin Kyu Lee ◽  
Dong In Jang ◽  
Shae K. Kim
Keyword(s):  
Grain Size ◽  
Liquid Fraction ◽  
Isothermal Holding ◽  
High Strength ◽  
Industrial Applications ◽  
High Productivity ◽  
Die Life ◽  
Average Grain Size ◽  
Low Energy Consumption ◽  
Holding Temperature

Thixoextrusion, one of the thixoforming processes, has advantages of high productivity, reduction of the extrusion pressure, extension of the die life, and cost saving owing to its low energy consumption compared with the conventional extrusion processes. Especially, thixoextrusion process is expected to be very effective for hard-to-form materials with high strength. The present study focuses on 7075 Al wrought alloy to investigate the potential industrial applications of the thixoextrusion process. The microstructural evolution of 7075 Al wrought alloy for thixoextrusion was investigated with respect to isothermal holding temperature and time in the partially remelted semisolid state. The results showed that the liquid fraction increased with increasing isothermal holding temperature and time while the average grain size was inversely proportional to isothermal holding temperature and time up to 5min. However, there was no big change of liquid fraction and average grain size with respect to isothermal holding temperature and time. The important fact that the liquid fraction and average grain size were almost uniform after 5 min holding time is considered very useful for thixoextrusion in terms of process control.

scholarly journals Recycling Glass Cullet from Waste CRTs for the Production of High Strength Mortars

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Stefano Maschio ◽  
Gabriele Tonello ◽  
Erika Furlani
Keyword(s):  
Compressive Strength ◽  
Fine Fraction ◽  
High Strength ◽  
Leaching Tests ◽  
Glass Cullet ◽  
Glass Waste ◽  
Small Glass ◽  
Cathode Ray Tube ◽  
Overall Performance ◽  
Icp Analysis

The present paper reports on the results of some experiments dealing with the recycling of mixed cathode ray tube (CRT) glass waste in the production of high-strength mortars. Waste CRT glass cullet was previously milled, and sieved, and the only fine fraction was added to the fresh mortar in order to replace part of the natural aggregate. The addition of superplasticizer was also investigated. All hydrated materials displayed high compressive strength after curing. Samples containing CRT mixed glass showed a more rapid increase of strength with respect to the reference compositions, and materials with a superplasticizer content of 1% showed the best overall performance due to the favourable influence of the small glass particles which increase the amount of silicate hydrated produced. The induced coupled plasma (ICP) analysis made on the solutions, obtained from the leaching tests, confirmed the low elution of hazardous elements from the monolithic materials produced and consequently their possible environmental compatibility.

scholarly journals Unconventional Technique for Producing Borosilicate Glass Foam

2021 ◽  
Vol 1 (6) ◽  
pp. 12-22
Author(s):  
Lucian Paunescu ◽  
Marius Florin Dragoescu ◽  
Sorin Mircea Axinte ◽  
Felicia Cosmulescu
Keyword(s):  
Thermal Conductivity ◽  
Borosilicate Glass ◽  
Specific Energy Consumption ◽  
Microwave Oven ◽  
Experimental Equipment ◽  
Glass Waste ◽  
Homogeneous Microstructure ◽  
Advanced Technique ◽  
The World ◽  
Glass Foam

The study aims to test an advanced technique but insufficiently valued in the world in the process of experimental manufacture of borosilicate glass foam. It is about the unconventional technique of heating solids by using the microwave radiation converted into heat. The experimental equipment on which the tests were performed was a 0.8-kW microwave oven commonly used in the household with constructive adaptations to be operational at high temperature. The adopted manufacturing recipe was composed of borosilicate glass waste with the addition of calcium carbonate, boric acid and water in different weight proportions. The material was sintered at 829-834 ºC by predominantly direct microwave heating and the optimal foamed product had characteristics similar to those manufactured by conventional techniques (apparent density of 0.33 g/cm3, thermal conductivity of 0.070 W/m•K, compressive strength of 3.1 MPa and a homogeneous microstructure with pore size between 0.7-1.0 mm). The energy efficiency of the unconventional manufacturing process was remarkable, the specific energy consumption being only 0.92 kWh/kg.

scholarly journals Sustainable design of concrete using industrial additives and wastes

2021 ◽  
Author(s):  
Bintul Zehra ◽  
Ali Salem ◽  
Souphavanh Senesavath ◽  
Saied Kashkash ◽  
Zoltan Orban
Keyword(s):  
Portland Cement ◽  
Construction Material ◽  
Steel Slag ◽  
Industrial Processes ◽  
Partial Replacement ◽  
Concrete Technology ◽  
River Sand ◽  
Glass Waste ◽  
Fine Aggregates ◽  
By Products

AbstractConcrete is the most widely used construction material in the world. Over ten billion tons of concrete are being produced each year resulting in exhaustion of natural materials and an enormous carbon footprint. One of the primary goals of concrete technology today is to reduce the use of Portland cement and natural fine aggregates by partially replacing them with various waste materials and by-products of industrial processes. The paper summarizes the results of a study where the partial replacement of river sand and Portland cement was successfully applied using steel slag aggregate, silica fume and glass waste.

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