S.C. Code Ann. § 10-9-150

As a condition precedent to the right to dig, mine, and remove the rocks and deposits granted by a license, each licensee shall enter into bond, with security, in the penal sum of five thousand dollars, conditioned for the making at the end of every month of true and faithful returns to the Comptroller General of the number of tons of phosphate rock and phosphatic deposits so dug or mined and the punctual payment to the State Treasurer of the royalty provided at the end of every quarter or three months. The bond and sureties are subject to the approval required by law for the bonds of state officers.