The company was purchased by a joint venture comprised of Grupo Acerero del Norte (51%) and Mission Energy of the U.S. (49%). ... Regulations of the new Mining Law, which became effective in September 1992, as well as the aquot;Manual de Servicios al Publico en Materia ... The law extended the term of exploitation concessions from 25 to 50 years, renewable for a similar period, while explorationanbsp;...
|Title||:||Statistical Appendix to Minerals Yearbook|
|Author||:||United States. Bureau of Mines|