Reserves and Resources

Mineral Resource and Ore Reserve Statement - June 2005

Figure 1 Plan of Resource Areas

Major Changes since annual report 2004

Since the last declaration of mineral resources and ore reserves:

• detailed drilling has continued in the Ngezi area and reconnaissance drilling has been completed to the north of Hartley

• Zimplats has remodeled the entire mineral resource base.   

The result is that the underlying geological model has increased in terms of tonnages and metal content. These increases are due to:

• Previously a fixed width of 1.2m and a grade of 2g/t platinum had been assigned to the Inferred Resource.  In the current model, the width and grade have been estimated, based on the data available.  This has increased the width and reduced the grade.

• More realistic geological losses have been applied, based on a re-evaluation of the data and on recent mining experience.  Previously a blanket 3% loss was applied while currently factors range from 2 to 20% depending on the geological conditions. 

During the past year a new release of the JORC Code has been issued and Zimplats has prepared a code of practice based on this revision.  Zimplats has decided that the Code would be more closely honoured if

• losses due to inevitable pillars underground and,

• inherent dilution caused by the extent of micro faulting and minor intrusions are allowed for in the mineral resource declaration.  The resulting mineral resource is compared with previous estimates in Table 1

Table 1 Mineral Resource Comparison

Of this mineral resource, oxides comprise 138 million tonnes containing 8 million ounces of platinum. The metallurgical recoveries using current technology are lower for this material. 

The measured component of this resource has increased by 8% due to recent drilling. 

The company has gained considerable experience mining underground at Portal 2 and this was compiled into a full feasibility study.  In order to comply with the change in the JORC Code that requires a mine plan for all ore reserves, SRK Consulting in Johannesburg has prepared appropriate mine plans and financial models. 

The resulting ore reserve declaration is shown in Table 2

Table 2 Ore Reserve Comparison

The reduction in ore reserves has been due to

• a change to the maximum dip for room and pillar mining from 12 degrees previously to 9 degrees as a result of experience within the Implats Group.

• refinements in underground mine design which highlight the need for inferred mineral resources to be progressed to generate additional ore reserves. These inferred mineral resources lie adjacent to the deepest part of the previous ore reserve area.

• reduced extraction rates,  especially in the deeper parts of the  ore reserve.

• drilling and subsequent refinement of the ultimate open pit design which resulted in a reduction in tonnage. Some of these open pit ore reserves may be mined in future from underground due to the significant cost differential between the two mining methods. 

Ore reserves were increased by drilling in the Portal 3 Area.

Notes on the Mineral Resource and Reserve Declaration

The ore reserves quoted reflect anticipated grades delivered to mill.

• Resources have been estimated using floating average and kriging techniques on data derived from surface diamond drill holes.   Estimates are based on composite widths that vary depending on cut off grades, which are based on appropriate economic conditions.
• This declaration based on some 1690 diamond drill holes totaling 235 000m that have been drilled by various companies since the 1960s.  The majority have been drilled by Zimplats and its predecessors since 1990 and nearly half lie in the southern 30km, the Ngezi Area.
• In addition to the pre-feasibility study, SRK Consulting carried out an external review of platinum mineral resource and ore reserve estimation and reporting practices in September 2004 and updated July 2005.  SRK concluded that Mineral Resource estimates are valid and that within the limitations of the data, the results appear meaningful.
• During 2005, the company has been restructured so that all of Zimplats mineral resources are owned 100% by Zimplats through its wholly owned subsidiaries.  Previously the open pit and Hartley mineral resources were owned 30% by Implats.  The Implats shareholding has increased to 86.1% of Zimplats as at 30 June 2005.

Competent Persons

The information in this report that relates to Ore Reserves is based on information compiled and reviewed by Jonathan Wheeler who is a Professional Engineering Technologist  registered with The Engineering Council of South Africa. 

The information in this report that relates to Mineral Resources of the Exploration and Evaluation Areas is based on information compiled by Andrew du Toit who is a Member of The Australasian Institute of Mining and Metallurgy. 

The information in this report that relates to Mineral Resources of the Ngezi Open Pit and Underground Operational Areas (Portals 1 and 2) is based on information compiled by Sydney Simango who is a Member of The Australasian Institute of Mining and Metallurgy