Atık döküm malzemelerinden katma değerli kimyasal inorganik cam kaplama malzemelerinin üretimi
Production of value added chemical inorganic glass coating materials from waste casting materials
Yazar: DOĞUKAN İLBEY ÖREN
Danışman: PROF. DR. HÜSEYİN ÖZKAN TOPLAN
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Metalurji ve Malzeme Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Kimya = Chemistry ; Metalurji Mühendisliği = Metallurgical Engineering
Dizin: Anorganik kimya = Inorganic chemistry ; Seramik kaplama = Ceramic coating ; Seramik kaplama malzemeleri = Ceramic covering equipments ; Yüzey kaplama = Surface coating ; Yüzey kaplama malzemeleri = Surface coating materials

Özet:
Bu çalışmada, endüstride uygulamaları sürmekte olan kum kalıba döküm sonrası oluşan ve kullanıma uygun olmayan malzemenin (atığın), cam-seramik üretimi için hammadde olan frit üretiminde sürdürülebilir, uygun maliyetli CaO, SiO2, Al2O3 ve ZrO2, TiO2, ZnO vb. inorganik oksitlerin ikamesi olarak kullanımı araştırılmıştır.
Ticari olarak temin edilebilen bir friti (STD-F) kum kalıba döküm atığından (KKA-F) yapılan fritle karşılaştırmak için, ergitme-su verme teknikleri ile iki farklı frit üretilmiştir ve karakterize edilmiştir. Camsı yapıya sahip fritlerin kimyasal bileşimi, faz oluşumu ve termal özellikleri XRF, XRD, SEM, EDX, ısı mikroskobu, dilatometre ve TG-DTA, analiz yöntemleri kullanılarak değerlendirilmiştir. Fritler sulu olarak alumina bilyalarla öğütülmüş ve tane boyutları ölçülmüştür. (d90) 20-30uµ 'dan küçük olan tanecik boyutunda fritler elde edilmiştir. Fritlerin her ikisi içinde, reçete hazırlanarak, ticari bakır-kromit oksit içeren toz pigment ve ticari olarak kullanılan medium ile beraber cam-seramik cam kaplama malzemesi haline getirilmiştir.
Soda-kireç cam altlık üzerine serigrafi yöntemiyle kaplama malzemesş her iki boyada 77 mesh ile uygulanmıştır, daha sonra cam-seramik kaplama elde etmek amacıyla 660 °C'de 7 dakika boyunca kristalize edilmiştir. XRD, SEM analizleri kullanarak; referans (STD-F) ve kum kalıba döküm atığı içeren ikameli sürdürülebilir (KKA-F) kaplamalar faz oluşumu, mikro yapı ve kimyasal direnç açısından araştırılmıştır. Cam-seramiklerin XRD modelinde incelenen STD-F termal özellikleri ile (KKA-F) ilişkilendirilmiştir. Yüzey ve ara yüzey görüntüleri için SEM kullanılmış ve bu bölgelere EDX analizi ile elemental analiz sağlanmıştır.
Endüstride uygulanan, renk ölçümleri ASTM D2244-23, parlaklık ölçümleri ASTM D523-14, örtücülük gücü ASTM D2805 standartları ile ölçümlenmiştir. TS EN 14483 ile sitrik asit, nitrik asit ve hidroflorik asit dayanımları cam yüzeyinde karşılıklı olarak incelenmiştir. Yapılan bu analizler STD-F ve KKA-F fritlrerinin benzer ve farklı yönlerini araştırmıştır. Bu çalışmada, atık malzeme ile üretilen fritin maliyet olarak kar sağlaması, stok ve atık sorunlarının önüne geçmesi, katma değerli ürüne dönüşmesi ve cam kaplama malzemeleri alanında bir ihtiyaca çözüm olması, ekonomi ve doğaya katkı sağlaması hedeflenmiştir.

Abstract:
Glass is a very ancient and antique material. The art of glassmaking has a history of 5,000 years, but even before that, obsidian, which is natural glass, was used in tool production. It is highly likely that people produced glass without knowing it for the first time. However, soon after, this new material began to be processed with great creative skill, and as a result, the first glasses started to be used as valuable decorative jewelry. Later on, using glass as a vessel came into question, for which powdered raw material of glass was weighed and then melted, making it viscous and formed around a core. Processing glass in a more liquid state probably failed due to the lack of a pot material durable enough. The composition of ancient Egyptian glasses is not only known from analyses but also from cuneiform tablets in the library of Ashurbanipal, providing information about the chemical structure of the first glasses. These glasses were produced with about 70% SiO2 by weight (along with some Al2O3), about 10% CaO by weight (along with some MgO), and about 20% Na2O by weight (along with some K2O). Therefore, it is believed that the first glasses were soda-lime glasses. Glassmaking had a production monopoly that started with the Egyptians for the necessary amount of soda and later passed to Venice through the Romans. The first decisive change in glass production was probably the invention of the blowpipe for glassblowing, which occurred around the 1st century BC. A better pot material now allowed the glass to be heated more and then blown; this created its own technology for glass, which remained almost unchanged for 2,000 years.
In this study, the use of waste material (which is unsuitable for use) generated after sand mold casting, still applied in the industry, as a substitute for sustainable, cost-effective inorganic oxides such as CaO, SiO2, Al2O3, ZrO2, TiO2, and ZnO in the production of frit, which is a raw material for glass-ceramic production, was investigated. 
Two different frits were produced and characterized using melting-quenching techniques to compare a commercially available frit (STD-F) with a frit made from sand mold casting waste (KKA-F). The chemical composition, phase formation, and thermal properties of the frits, which have a glassy structure, were evaluated using XRF, XRD, SEM, EDX, hot stage microscopy, dilatometer, and TG-DTA analysis methods. The frits were ground with alumina balls in an aqueous medium, and their particle sizes were measured. Frits with particle sizes smaller than (d90) 20-30 µm were obtained. For both frits, a recipe was prepared, and a glass-ceramic glaze material was created with a commercially used medium and a commercial copper-chromite oxide-containing powder pigment. 
The coating material was applied to soda-lime glass substrates using the screen-printing method at 77 mesh for both frits and then crystallized at 660°C for 7 minutes to obtain glass-ceramic coatings. Using XRD and SEM analyses, the reference (STD-F) and the sustainable frit containing sand mold casting waste (KKA-F) coatings were investigated in terms of phase formation, microstructure, and chemical resistance. The thermal properties of the STD-F examined in the XRD model were correlated with (KKA-F). SEM was used for surface and interfacial images, and elemental analysis was provided to these regions with EDX analysis. 
Color measurements applied in the industry were measured according to ASTM D2244-23, gloss measurements according to ASTM D523-14, and opacity power according to ASTM D2805 standards. The resistance to citric acid, nitric acid, and hydrofluoric acid on the glass surface was comparatively examined with TS EN 14483. These analyses investigated the similarities and differences between STD-F and KKA-F frits. In this study, the frit produced with waste material is aimed to provide cost savings, prevent stock and waste issues, transform into a value-added product, and offer a solution to a need in the field of glass coating materials, contributing to the economy and the environment.
In this study, unused foundry sand waste from the sand casting process was incorporated into a frit formulation, traditionally composed of commercial raw materials such as quartz (SiO2), aluminum oxide (Al2O3), and zirconium dioxide (ZrO2), for the production of glass-ceramic coatings. The experimental process involved ten main steps: grinding the foundry sand waste (KKA), characterizing the KKA, preparing the frit formulation, weighing and producing the frit, manufacturing both standard commercial frit and KKA-added frit, grinding and sieving the frits, preparing and producing the paint formulation, screen printing on soda-lime glass, drying and firing, and conducting industrial tests on the prepared coatings. 
After analyzing the frits, commercial copper-chromite pigment and organic carrier were used to produce glass paint from both the standard frit (STD-F) and the KKA-added frit (KKA-F). The produced glass paint was applied using a 77 mesh screen print, and tests were conducted to measure wet film thickness, gloss, opacity, color analysis, and chemical resistance for both frit-derived coatings. The results showed that the glass coating material produced from KKA-F exhibited higher opacity, similar color, and more matte appearance compared to the STD-F derived coating.
The citric acid, nitric acid, and hydrochloric acid tests demonstrated similar behaviors for both STD-F and KKA-F coatings. These findings indicate that it is feasible to use KKA as a sustainable raw material source in glass paint production without any preliminary processing, as evidenced by the comparable surface properties and industrial test results of the coatings. The metal oxides in the foundry sand waste, as discussed in the literature, are suitable for use in glass-ceramic frit formulations, specifically within the SiO2–B2O3–Na2O–Al2O3–K2O–F systems. 
Glass-ceramic coatings were prepared using 20-40% commercial copper-chromite pigment, 60-80% frit, and 25-30% commercial solvent carrier material, each mixed for 15 minutes. The prepared coatings were applied to glass surfaces via screen printing, followed by pre-drying at 150-200°C and final drying at 660°C for 5 minutes. XRD analysis was conducted on the re-fired frits to observe the formation of glass-ceramic crystals. The XRD results for both STD-F and KKA-F frits showed that an amorphous structure was achieved through rapid cooling from 1300°C. The exothermic peaks identified in the DTA results determined the crystallization temperatures, leading to working ranges of 660°C and 730°C for glass-ceramic coatings. 
The STD-F frit, fired at 660°C, showed initial crystallization of lithium aluminum oxide at 2θ:55°, while further crystallization at 730°C included lithium zinc silicate, zircon, lithium aluminum silicate, and titanium silicate. In contrast, the KKA-F frit, fired at 660°C, showed the formation of zinc iron aluminum oxide, lithium zinc silicate, and andradite, with more crystalline structures emerging compared to STD-F, likely due to the complex composition of the KKA. At 730°C, the KKA-F frit exhibited additional crystalline phases, including maghemite, silica, aluminum oxide, aluminum boron oxide, zirconium oxide, zinc chromium fluoride, chromium aluminum oxide, calcium silicon oxide, hematite, and potassium titanium silicate. SEM and EDS analyses were performed on both coatings to examine the film and glass-ceramic structures, confirming the XRD results and identifying the relevant elements.