How to understand the heat conduction in LB?

Hi, everyone,
When to simulate the heat conduction problem with two different material, I supposed two different thermal diffusion coefficients to decide the relaxation times. Then, the simulation result reached a stable temperature distribution. According to the temperature distribution, the thermal conductivity can be obtained, but only the thermal diffusion coefficients are given in the initial.
How to undertand the problem with given thermal diffusion coefficient deducing the thermal conductivity?