Tenn. Code Ann. § 4-6-137

The commissioner of correction, by and with the consent and approval of the governor, is authorized to enter into such contracts for the sale of all coal mined at the state mines, situated at Petros, as are permitted by § 41-22-106, the contracts to be made at such prices and covering such periods of time as, in the opinion of the commissioner, will best subserve and protect the interests of the state and the welfare of the inmates. The contracts are to be made and entered into without the necessity of advertising.