Utilization of calcite produced in Turkey for paper coating

Calcium carbonate is one of the coating pigments widely used in paper industry. Especially, in recent years calcium carbonate filler has gained high importance in alkaline pulping. In Turkey industry actually imports calcium carbonate; whereas, there are rich calcite reservoirs in the country. In this study two different types of domestic ground (GCC) calcite samples were used. Physical and chemical properties of calcite samples were tested firstly. CaCO3 percentages of both samples were 97.3 % and 97.6 % (min. 95 % CaCO3). MgCO3 and Fe2O3 percentages were within the desired limits. Brightness values were 95.5 % and 94.5 % and yellowness 1.1 % and 1.5 % elrepho. These values also were within the requested limits. Under 2 microns particle size and over 10 microns particle size fractions were 95 % and 89 % (min. 80) and 1 % and 2 % (max. 2) respectively. Dry matter rates were between 40 %-65 %, for the pilot plant-coating machine. During the preparation of coating color calcium carbonate has been used together with kaolin. The ratios of calcium carbonate to kaolin were 30/70, 40/60, 50/50, 60/40, 70/30, 100/0. In coating color preparation latex was used as a binder because of its wide applications. Latex percentages were 11, 12, and 13 %. Coated papers were glossed and physically tested. As a result, both calcium carbonate samples were found suitable for using in coating color preparation. By the utilization of domestic calcium carbonate in coated paper production, there will be foreign currencies saving.

Türkiye’de üretilen kalsitin kuþe kaðýt yapýmýnda kullanýlmasý

Kalsit (CaCO3), kaðýt endüstrisinde yaygýn olarak kullanýlan bir kuþeleme pigmentidir. Ayrýca, son yýllarda kalsit, dolgu maddesi olarak uzun ömürlü alkali kaðýt yapýmýnda da büyük bir önem kazanmýþtýr. Türkiye’de zengin kalsit yataklarý olmasýna raðmen kaðýt sanayiinde kullanýlan kalsit ithal edilmektedir. Bu çalýþmada, iki tip yerli toz (GCC) kalsit kullanýlmýþtýr. Bu örneklerin CaCO3 oraný % 97.3 ve % 97.6 (min. % 95)’dýr. MgCO3 ve Fe2O3 oranlarý ise, istenen sýnýrlar içersindedir. Örneðin parlaklýk deðerleri % 95.5 ve % 94.5 sarýlýk deðerleri ise % 1.1 ve % 1.5 elrepho olarak belirlenmiþtir. 2 mikronun altýndaki ve 10 mikronun üzerindeki fraksiyonlar sýrasýyla % 95, % 89 ve %1 ve % 2 olarak bulunmuþtur. Kuþe pilot tesisinde, kuþe boyasý konsantrasyonu % 40- % 65 arasýnda alýnmýþtýr. Hazýrlanan kuþe boyasýnýn kalsit ve kaolen oranlarý 30/70, 40/60, 50/50, 60/40, 70/30 ve 100/0’dýr. Kullanýlan latex yapýþtýrýcý deðerleri ise % 11, % 12 ve % 13’dür. Kuþelenen kaðýtlar perdahlama öncesi ve sonrasý fiziksel ve optik testlere tabi tutulmuþlardýr. Sonuç olarak her iki CaCO3 örneklerinin fiziksel ve optik özellikleri bakýmýndan kuþeleme için uygun olduðu anlaþýlmýþtýr. Yerli kalsit rezervlerinin kullanýlmasý ülkemiz için döviz tasarrufu saðlayacaktýr.