Treatment apparatus for high-precision analysis of impurities in silicic material

A treatment apparatus for analyzing the impurities in silicic material with high precision comprising:

• (1) a container having at inner space in which at least one analysis sample container and a sample decomposing solution are accommodated;
• (2) wherein said container is divided into a lid body having an inner space therein and a lower body having an inner space therein, each of said lid body and said lower body being opened at a division surface side thereof to have an open end portion and being closed at the surface side opposite to the division surface side to have a closed end portion thereof, the inner surface of the closed end portion of said lid body being formed in a concave shape to form a ceiling portion while the closed end portion of said lower body forms a bottom portion at which the sample decomposing solution can be stocked;
• (3) wherein the inner peripheral surface of the open end portion of said lower body is formed in a stepwise shape so that said analysis sample container is disposed to be spaced from the surface of the decomposing solution which is stocked at the bottom portion, and the inner peripheral surfaces of said lid body and the lower body are smoothly continuously threadily engaged with each other through abutment faces thereof;
• wherein each of the lid body and the lower body has, as an engagement means, an abutment face portion and a screw portion at the open end thereof, said abutment face portion having a surface roughness (Ra) of 0.1 to 3 .mu.m, said screw portion having a thread pitch of 1 to 3 mm, a length of 10 to 70 mm and a flank portion thereof having a surface roughness (Ra) of 0.1 to 3 .mu.m, and
• wherein the lid body and the lower body are threadily engaged with each other through engagement between the screw portions thereof, and the inner peripheral surface of the container at the abutment portion of the lid body and the lower body forms a smooth continuous surface, and wherein the container has such a sealing state that the inner space thereof can be kept at a pressure range of 0.01 to 0.500 MPa.