The board of supervisors of any county and the governing authorities of any municipality are authorized and empowered, in their discretion, to grant exemptions from ad valorem taxes on real property:
Which is owned by a nonprofit industrial foundation, corporation or like association organized and operated for the public purpose of promoting economic and industrial development; and
Which is acquired for the sole purpose of making sites available for industrial development; and
When no part of the income thereof inures to the benefit of any private stockholder or individual.