Evaluation of Diffusibility of Boron in Wood under Water Leaching Conditions

Radial and tangential diffusion coefficients of boron in wood under water leachlng conditions were determined from the change of concentration profiles of boron. Ebmer's solution was used to obtain variable diffusion coefficients of boron because it has been known to be the only method to determine variable diffusion coefficients with no cumbersome assumption. The values of diffusion coefficients were between 0.18 X 10.~c m2/sec and 25.6 Y 10.~c m2/sec. They increased with the increase of sample thicknesses, and decreased with the increase of leaching times. There was a region where Egner' s method was not valid. However, Egner' s solution illustrates a convenient way to evaluate difhsion characteristics of boron from wood under water leaching conditions. The difhsion coefficients at wood surface may be regarded as leaching coefficients.