Containing by weight, singly or together, more than 50% of

69.02 - Refractory bricks, blocks, tiles and similar refractory ceramic constructional goods, other than those of siliceous fossil meals or similar sihceous earths (+). 6902.10 - Containing by weight, sin ly or together, more than 50 % of the elements 6902.20 - Containing by weight more than 50 % of alumina (A1203),of silica (SiOz)or 6902.90 - Other B Mg, Ca or Cr, or expresse as MgO, CaO or Cr203 of a mixture or compound of these products This heading covers a group of refractory roducts (other than those of headin 69.01 normally used in the construction of ovens, h s, furnaces or other plant for the meta6uTgical chemical, ceramic, glass and other industries. I I It includes, inter alia : (1) Bricks of all shapes arallelepiped, wedge shaped, cylindrical, semi-cylindrical, etc.), including keystones an other specially shaped bncks e.g., runner bricks, concave on one face and rectilinear on the others) even if they are clear y reco isable as being of the kind specially designed for the consbxction of plant or machinery o Section XVI. 's r . (2) Refractory blocks and tiles for flooring, walls, hearths, etc. The heading excludes tubing, piping (including runways in the form of half-cylinders) and angles, bends and similar tube or pipe fittings of refractory materials (heading 69.03).

Subheading Explanatory Note. Subheading 6902.10 What has to be determined for the urposes of this subheading is the content of MgO, CaO or Cr203.This is normall done by determining e contents of the elements present (i.e., Mg, Ca or Cr) and fiom these amounts d e equivalent concentrations in terms of their oxides can be calculated. Far example, 40 % Ca is e uivalent to 56 % CaO and 24 % Mg is e uivalent to 40 % MgO. Thus, a product based on calcium s&cate containing 40 % Ca (equivalent to 56 X CaO) would be classified in this subheading. Y