If mineral lands upon which improvements have been made shall be leased in conformity with law to other than the owner of such improvements thereon, then such purchaser or such new lessee shall pay to the owner thereof the value of such improvements at an agreed price with the owner thereof; and if such owner of improvements and such new lessee or purchaser are not able to agree upon a value, the value shall be determined by a board of three arbitrators, one to be selected by the owner of the improvements, one by the commissioner of public lands and the third by the two so selected. The word “improvements” shall be construed to mean surface improvements, machinery and other equipment not removed from said lands under the provisions of Section 9 used in the operation of the plant on such land, and work performed in the development of the property for operation and mining. No lease shall be issued to any applicant other than the owner of such improvements until such applicant files with the commissioner of public lands a receipt showing payment in full of the value of such improvements as agreed upon between such applicant and the owner of the improvements, or determined by the board of arbitrators; or until such applicant shall pay to the commissioner of public lands the value of such improvements so determined. If payment is made to the commissioner of public lands it shall be at once delivered to the owner of the improvements.