Neutron Texture Investigations on Natural Mt. Isa Chalcopyrite Ore–Part I: Preferred Orientation of one and the Same Chalcopyrite Sample Before and After Experimental Deformation

Abstract

Natural chalcopyrite samples from Mt. Isa, Australia were axially shortened with a constant strain rate of 3-10 -5 sec-, at a constant confining pressure of 300 (400) MPa and at different temperatures. Neutron diffraction texture analyses were carried out before and after experimental deformation on one and the same sample. The preferred orientation of the experimentally undeformed samples consists of three main orientation components, which become weaker with deformation at temperatures up to 200C. One or two new components develop with the c-axes perpendicular to the principal strain direction. At a deformation temperature of 300C two very different new components develop, the original components are completely dissolved.

Neutron Texture Investigations on Natural Mt. Isa Chalcopyrite Ore – Part II: Preferred Orientation of Chalcopyrite After Different Experimental Deformation Conditions

“…Isa ore is: 85% chalcopyrite, 3% pyrrhotite, 1% pyrite and 11% quartz and other minerals, the average grain diameter of chalcopyrite being 0.3 mm. Collectively 28 cylindrical specimens of 30 mm in length and 15 mm in diameter had been axially shortened in two series (Jansen et al, , 1995. A constant confining pressure of 300 MPa (400 MPa for room temperature), temperatures in the range 25-450C and strain rates in the range 3-10-5-6-10msec -1 were used for shortening test to 32% total strain.…”

“…The pole figures of eight undeformed specimens, which showed similar positions and only slight differences of the intensities for the maxima (Jansen et al, 1995), were summed up and mean pole figures were calculated, which are representative for the complete handspecimen from Mt. Isa (Figure 1).…”

“…Thus, a new series of Mt. Isa chalcopyrite analysed by neutron diffraction has revealed a distinct preferred orientation for the experimentally undeformed ore (Part I of this contribution, Jansen et al, 1995). As the deformation induced preferred orientation is distinguished now from the original preferred orientation, an investigation of all samples of the previous series was carried out by neutron diffraction.…”