Zimplats

 

Zimplats
 

Mineral Resources and Ore Reserves

Zimplats’ Ngezi Mine is located approximately 150km south-west of Harare at the southern end of the Sebakwe sub-chamber of the Hartley Complex on the Great Dyke. The Hartley Complex is about 100km long and contains 80% of Zimbabwe’s PGM resources and Zimplats controls two-thirds of this. The mothballed Hartley Mine and the Selous Metallurgical Complex are located 77km north of the Ngezi Mine in the Darwendale sub-chamber. Zimplats holds a special mining lease covering two areas totalling 48 535ha.

The platinum-bearing Main Sulphide Zone (MSZ) is located in the P1 pyroxenite some 10m to 50m below the ultramafic/mafic contact. The MSZ is a continuous layer, 2m to 10m thick, and forms an elongated basin.

 

The zone strikes in a north-north-easterly trend and dips between 5° to 20° on the margins flattening towards the axis of the basin. Peak base metal and PGM values are offset vertically with palladium peaking at the base, platinum in the centre and nickel towards the top. Visual identification of the MSZ is difficult.

Production is presently sourced from three decline shafts or portals, with a fourth portal currently under development. Boundaries between individual portals are usually based on major faults. Minor faults and other disrupted areas are present and are taken into account in the Mineral Resource and Ore Reserve statements as geological losses. No potholes, as experienced in the South African operations, have been identified.

Open pit strip mining at Zimplats commenced in 2002 at Ngezi. This was suspended in 2008 and all mining is presently conducted in underground sections.

Zimplats employs mechanised bord and pillar mining to mine ore from stopes with a nominal width of 2.5m at dips of less than 9°. Each production team comprises a single boom face rig, a bolter, a 10t LHD and a 30t dump truck and mines 20 panels, each 7m wide. This allows sufficient flexibility for the required grade control sampling and to negotiate faults and intrusions while still meeting the team’s target of 20 000t per month. The default layout has 7m roadways with 4m square pillars, spans decrease and pillar dimensions increase in bad ground and with depth. A combination of roof bolts and tendons is integral to the support design. The mining infrastructure presently consists of decline accesses via surface portals. All three portals are currently operating at full design capacity. Following Board approval early in 2011, construction of the new two million tonne per annum mine at Portal 3 (Mufuti Mine) commenced, the box cut is complete and initial underground access established.

In the next five years production will increase from the current 4.5 Mt per annum to 6 Mt per annum, which is sustainable until FY2042. Portals 1 to 4 constitute LoM I and portals 5 to 7 LoM II. LoM III is made up of future mining from Portal 8. The potential growth beyond the 6Mt profile is dependent on a range of technical, economic and political considerations. The LoM profile shown below is based on assumptions and may change in future.

 

 

Zimplats Mineral Resources and Ore Reserves (100%)  
as at 30 June 2012

 Mineral Resources         as at 30 June 2012         as at 30 June 2011  
    Tonnes   Width   4E  
grade  
6E  
grade  
Ni   Cu   4E   6E   Pt   Tonnes   4E  
grade  
6E  
grade  
4E   Pt  
 Orebody   Category   Mt   cm   g/t   g/t   %   %   Moz   Moz   Moz   Mt   g/t   g/t   Moz   Moz  
 Ngezi Portals –
 Advanced to reserve  
                           
 MSZ   Measured   80.0   250   3.47   3.67   0.10   0.07   8.9   9.4   4.5   69.7   3.47   3.66   7.8   3.9  
  Indicated   212.3   250   3.49   3.69   0.11   0.08   23.8   25.2   11.9   226.9   3.48   3.67   25.4   12.6  
  Total   292.4     3.49   3.68   0.11   0.08   32.8   34.6   16.4   296.5   3.47   3.67   33.1   16.5  
 Ngezi Portals –
 Not advanced to reserve  
                           
 MSZ   Measured   44.9   250   3.36   3.55   0.10   0.09   4.9   5.1   2.3   46.0   3.36   3.55   5.0   2.4  
  Indicated   252.8   229   3.43   3.62   0.12   0.09   27.9   29.4   13.7   252.8   3.43   3.62   27.9   13.7  
  Inferred   133.5   200   3.44   3.63   0.13   0.08   14.7   15.6   7.6   133.5   3.44   3.63   14.7   7.6  
  Total   431.2     3.42   3.61   0.12   0.09   47.5   50.1   23.6   432.3   3.42   3.61   47.6   23.7  
 Mining Lease north of
 Portal 10  
                           
 MSZ   Indicated   53.8   127   4.56   4.80   0.22   0.18   7.9   8.3   3.6   53.8   4.56   4.80   7.9   3.6  
  Inferred   829.1   183   3.59   3.79   0.15   0.13   95.8   101.0   45.1   829.1   3.59   3.79   95.8   45.1  
  Total   882.9     3.65   3.85   0.15   0.13   103.7   109.3   48.8   882.9   3.65   3.85   103.7   48.8  
 Hartley                              
 MSZ   Measured   28.3   158   4.53   4.78   0.14   0.12   4.1   4.3   2.0   28.3   4.53   4.78   4.1   2.0  
  Indicated   143.1   189   3.97   4.19   0.13   0.11   18.3   19.3   9.3   143.1   3.97   4.19   18.3   9.3  
  Inferred   46.3   191   3.89   4.10   0.13   0.10   5.8   6.1   3.0   46.3   3.89   4.10   5.8   3.0  
  Total   217.7     4.03   4.25   0.13   0.11   28.2   29.7   14.2   217.7   4.03   4.25   28.2   14.2  
 Oxides – all areas                              
 MSZ   Indicated   16.2   250   3.42   3.61   0.10   0.07   1.8   1.9   0.9   16.2   3.42   3.61   1.8   0.9  
  Inferred   63.5   219   3.48   3.67   0.12   0.10   7.1   7.5   3.5   63.5   3.48   3.67   7.1   3.5  
  Total   79.7     3.47   3.66   0.12   0.10   8.9   9.4   4.4   79.7   3.47   3.66   8.9   4.4  
Overall total   1 903.9     3.61   3.81   0.13   0.11   221.0   233.2   107.4   1 909.1   3.61   3.81   221.5   107.6  
                               
 Ore Reserves         as at 30 June 2012         as at 30 June 2011  
    Tonnes   Width   4E  
grade  
6E  
grade  
Ni   Cu   4E   6E   Pt   Tonnes   4E  
grade  
6E  
grade  
4E   Pt  
 Orebody   Category   Mt   cm   g/t   g/t   %   %   Moz   Moz   Moz   Mt   g/t   g/t   Moz   Moz  
 MSZ   Proved   66.3   263   3.36   3.55   0.10   0.07   7.2   7.6   3.6   55.9   3.39   3.58   6.1   3.0  
  Probable   160.9   268   3.35   3.56   0.10   0.08   17.3   18.4   8.5   164.4   3.40   3.60   18.0   9.0  
  Total   227.2     3.35   3.55   0.10   0.07   24.5   26.0   12.1   220.3   3.40   3.59   24.1   12.0  

 

Notes

  • The statement above reflects the total Mineral Resource and Ore Reserve estimate for Zimplats as at 30 June 2012. Corresponding estimated Mineral Resources and Ore Reserves attributable to Implats are summarised elsewhere in this report
  • Mineral Resources are quoted inclusive of Ore Reserves
  • Mineral Resource estimates allow for estimated geological losses, while no allowance is made for anticipated support pillar losses during eventual mining
  • The Ore Reserves quoted reflect anticipated grades delivered to the mill
  • Day-to-day operations are monitored using in-house lead collection fire assays with AA finish
  • The Mineral Resources and Ore Reserves in this statement are based largely on external nickel sulphide collection fire assays with ICP-MS finish. The differences between the methods are incorporated within the modifying factors that have been applied, which means that there may be slight distortions in recovery and other parameters
  • Nickel grades are stated as nickel in sulphide that is amenable to recovery by flotation
  • Mineral Resources have been estimated using kriging techniques on data derived from surface boreholes
  • Estimates are based on composite widths that vary depending on cut-off grades, which are based on appropriate economic parameters. The widths have been adjusted following the review work conducted by SRK in 2012
  • The main difference from the 2011 statement other than depletion can be ascribed to the wider widths in some areas and the slightly improved extraction rate in some areas
  • Rounding of numbers may result in minor computational discrepancies
  • More details regarding the Mineral Resources and Ore Reserves can be obtained in the 2012 Zimplats Annual Report.


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