Welcome to DJB Consultants Inc.

Our History as Comminution Consultants

DJB Consultants, Inc. was incorporated in November, 1999 and commenced operation in March, 2000 in Vancouver BC. During its 14 years of operation, its Principal Consultant (Derek J. Barratt, P. Eng.) has conducted assignments in Chile, Peru, Canada, USA, Mexico, Central America, Brazil, Spain and Sweden, with desk-top studies for projects in Australia, South Africa, Indonesia, and Yakutia.

Derek’s expertise has been developed during 30 years of consulting engineering preceded by 8 years in milling operations in various supervisory capacities.

Some of the “firsts” which have been recorded during this time are:

  • 1983: Conceptual study and pilot plant test work for the first 36 ft dia. SAG Mill with a GMD (Gearless mill drive, or ring motor) at 15,000 hp and commissioned in 1991.
  • 1986: Development and successful implementation of a Bond Work Index-based methodology for estimating power requirements for SAG milling and secondary Ball milling.
  • 1994: Sizing SAG Mills and Ball Mills at Batu Hijau for a 120,000 tpd plant from sampling PQ drill core and 105 geometallurgical samples (i.e., no bulk samples being available for pilot plant test work).
  • 1995: Sizing the first 40 ft dia. SAG Mill at Cadia Hill from Bond Work Index test work.
  • 1995: Upgrading motor power by 30% on the 34 ft dia. SAG Mill at Freeport Grasberg.

Our Clients: