Test Plant Operations

The Test Plant included all the key process unit operations in the flow sheet and combined them such that continuous operation was achieved for long periods of time allowing the collection of important operating data.

The Test Plant operated throughout 2013 and completed nineteen campaigns. The feed material was supplied by PT Antam from its Tanjung Buli operations (Buli), Halmahera Island.

Table 1: Variability of Plant Feed Compositions

Element % Buli Limonite Buli Saprolite Buli 75%S and 25%L Buli 50:50
Ni 1.24 1.78 1.54 1.55
Co 0.10 0.05 0.06 0.08
Al 3.14 1.95 2.19 2.67
Fe 44.4 15.8 22.3 30.7
Mg 1.3 12.8 10.0 6.9
Cr 2.00 0.76 0.95 1.44
Si 3.28 15.9 12.5 9.4
Mn 0.65 0.37 0.45 0.53

Process Performance

During the operation of the DNi Test Plant, process data was collected to compare with earlier bench scale results and to assist in the preparation of a process model.

The objective of process modelling was to establish a baseline model, grounded on chemical and thermodynamic fundamentals, to provide verification of the Test Plant Process and its mass and energy balances. Specific objectives of the modelling process included the following:

  • Simulate full closed loop process
  • Verify mass balances of key components
  • Generate water balance
  • Understand energy requirements
  • Identify information gaps
  • Provide a baseline for commercial scale-up
  • Provide a baseline for optimisation and sensitivity testing;

A simplified interactive schematic of the process is available here>