THE EFFECT OF KAOLIN AND SILICA VARIATION ON THE PROPERTIES OF PORCELAIN INSULATORS

Authors

  • HE Mgbemere DEPT. OF METALLURGICAL & MATERIALS ENGR’G, UNIV. OF LAGOS, AKOKA, LAGOS STATE. NIGERIA
  • IP Onyeayana DEPT. OF METALLURGICAL & MATERIALS ENGR’G, UNIV. OF LAGOS, AKOKA, LAGOS STATE. NIGERIA
  • AB Okoubulu DEPT. OF METALLURGICAL & MATERIALS ENGR’G, UNIV. OF LAGOS, AKOKA, LAGOS STATE. NIGERIA

Keywords:

Electrical porcelain, Shackle insulator, Kaolin, Feldspar, Processing.

Abstract

Clay, Al2O3, feldspar and silica have been used to produce shackle-type porcelain insulators using slip casting method. The amounts of silica and kaolin were varied from 10 to 30 wt. % while keeping the amounts of other constituents constant. The samples were bisque fired at 900oC, sintered at 1200oC for 1 hour glazed using borax fritz. The results showed that as the amount of kaolin decreased, apparent porosity and water absorption increased from 9-19 % and 7-12 % respectively. The bulk density and linear shrinkage decreased from 1.94-1.12 g/cm3 and from 12.5 % - 7 % respectively. Breakdown voltages ranging from 23 kV to 35 kV were obtained while the highest insulation resistance value of 50G? was for the sample with 55 % clay, 15 % silica and 25 % feldspar and 5 % Al2O3. The results indicate that moderate variations in kaolin and silica content can be used to produce porcelain insulators for commercial applications.

 

http://dx.doi.org/10.4314/njt.v38i3.15

Downloads

Published

2019-06-27

Issue

Section

Chemical, Industrial, Materials, Mechanical, Metallurgical, Petroleum & Production Engineering