PTR Minerals (ASX:PTR) said that results from drilling at the Duke and Nardoo saprolite targets, part of its Muckanippie Heavy Mineral Sands project in South Australia, show the expansion of "very high-grade" titanium discovery at the project, according to a Monday filing with the Australian bourse.

Mineralization remains open along strike at both prospects with potential to extend, and the drilling intercepted thick, high-grade heavy mineral from the surface at both targets, the filing said.

Results yielded 60 meters at over 39% grade of heavy mineral from the surface, including 6 meters at a grade of about 62% of heavy mineral from 25 meters, the filing added.

Analysis of heavy mineral samples also showed the potential for a high-quality ore and a high proportion of altered ilmenite, the company said.

Shares of the company rose 4% in recent Monday trade.