HIGH REFRACTIVE INDEX GLASS PRODUCTION USING LOCAL RAW MATERIALS
HIGH REFRACTIVE INDEX GLASS PRODUCTION USING LOCAL RAW MATERIALS
No Thumbnail Available
Date
2000-11
Authors
ISA, HAUWA
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Glasses of relatively high refractive index were produced using barite
from Azara in Nasarawa State and sand from Kenyi in Kachia Local
Government of Kaduna State. Prior to the glass production, preliminary
chemical analysis of the barite and sand were carried for moisture content, loss
on ignition and elemental composition by the use of Atomic Absorption
Spectrophotometer (AAS) and Flame Photometer. The oxide value of each
element was calculated and the following percentage compositions were
obtained using l.OOOg of each sample for the determination. The average of
three determinations for each element in both barite samples are shown below:
Sand Sample: Moisture content = 0.02, Loss on ignition = 0.06, Na20 = 0.121,
K20 = 0.947, Si02 = 98.39, CaO = 0.056, A1203 = 0.180, Fe203 = 0.029 MgO =
0.008 and R203 = 0.150. Baryte Sample A: Moisture content = 0.02, loss on
ignition = 0.06, Na20 = 0.025, K20 = 0.015. Baryte Sample B: Moisture
content = 0.026, loss on ignition = 0.044, CaO = 0.006, MgO = 0.024, Na20 =
0.028, K20 = 0.001, Si02 = 18.12, BaO = 65.02, Fe203 = 0.029, A1203 = 16.62.
Three batches were formulated considering the oxide composition of
the sand and the barite sample A due to its high BaO and low Si02 content.
B203 and ZnO were introduced as additional fluxing and fining agents in the
case of batch II, and only ZnO in batch III. The batches were test melted at a
temperature of 1,175°C in an electric furnace of heating capacity 1,200°C.
Batches II and III melted but batch I sintered. Similarly the batches were also
test melted by gas firing at 1,350°C. All the batches melted giving a reddish
brown paste due to contaminants. The three properties tested were refractive
index, density and thermal endurance. Refractive index and density were
determined by floatation method. The following results were obtained.
Based on the above results, the barite is good enough for optical glass
production.
Description
Thesis submitted to Department of Industrial
Design Faculty of Environmental Design
Ahmadu Bello University, Zaria.
BY
HAUWA ISA (MRS.)
NOVEMBER, 2000.
Keywords
HIGH, REFRACTIVE, INDEX, GLASS, PRODUCTION, USING, LOCAL, RAW MATERIALS