The proceeds derived from the sale of the bonds shall be deposited with the treasurer of the county wherein the operating school unit is located, in whole or in part, in a special fund to the credit of the operating school unit and shall be applied solely to the purposes for which the bonds were issued, except that the premium, if any, shall be placed in the sinking fund established by Section 59-71-150 and the accrued interest, if any, shall be used to discharge in part the first interest to become due on such bonds.