scenarios for the marine mining of heavy minerals

Scenarios for the Marine Mining of Heavy Minerals

Bart HogewegAndrina DrostRogier Kalis

Heavy Mineral Conference 2013Visakhapatnam, India27-29 November 2013

IHC Mining B.V.The Netherlands

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IHC Merwede Overview

IHC Merwede facts & figures:• Financial turnover in 2012: EUR 0.9 billion

• Staff in 2012: 3,200

• 5 Shipyards in The Netherlands, 1 in China; Singapore & Batam with Jaya Shipbuilding & Engineering

• World wide services and manufacturing locations

Outline

• Introduction• Marine mining technology• Mineral processing in marine environments• Marine mining scenarios• Conclusions

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Mining of the seafloor has been ongoing for a long time

• Offshore gold and tin mining started in early 1900s

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Introduction / Mining / Processing / Scenarios

Current marine mining activities are still based around historic areas…

• PT Timah operates offshore Indonesia with large integrated bucket ladder dredgers• In water depths to 50 m• Recently, IHC and PT Timah converted one of the dredgers to a hydraulic wheel

dredger, extending water depth to 70 m

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Source: PT Timah

Introduction / Mining / Processing / Scenarios

…but also moved into new areas

• De Beers Marine operates a mining vessel with a crawler offshore Namibia• Diamonds are mined from water depths to 150 m

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Source: De Beers Marine

Introduction / Mining / Processing / Scenarios

Heavy minerals are found offshore in relatively shallow water depths

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Offshore placers: Diamonds, gold, tin, heavy minerals (Ti-Zr)

PhosphatesCrust (Mn, Co)

Seafloor Massive Sulphides (Cu, Au, Zn)Nodules (Mn, Ni, Cu)

Source: GRID-UNEP

Introduction / Mining / Processing / Scenarios

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Heavy minerals are very suitable for dredge mining

• Richards Bay Minerals is world largest heavy minerals mining operation, using mining dredgers in multiple ponds

Introduction / Mining / Processing / Scenarios

How can we build a pond on the other side of the shore line?10

Introduction / Mining / Processing / Scenarios

Different concepts can be used for marine mining

• Stationary• Cutter/wheel suction dredger• Bucket ladder dredger

• Trailing• Trailing suction hopper dredger

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Introduction / Mining / Processing / Scenarios

Moving offshore brings in factors like wind, waves, currents etc.

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• Cutter suction dredgers are fixed to ground by spud wave action limits operation• Trailing suction hopper dredgers don’t have this limitation

Introduction / Mining / Processing / Scenarios

Wind and waves also have a large impact on the separation of heavy minerals

• Sea state and resulting vessel motions have impact on performance of separation equipment

• Vessel movements inhibit proper operation of spiral concentrators

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Introduction / Mining / Processing / Scenarios

Technology can provide solutions, but they come at a price

• Increase size of the platform to create more stability

• Motion compensation

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Source: Husky Energy

Source: Barge Master

Introduction / Mining / Processing / Scenarios

Combining mining and mineral processing results in different mining scenarios

• Integrated platform combining mining and mineral processing functions

• De-coupled functions

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Introduction / Mining / Processing / Scenarios

An integrated solution provides distinct benefits, but has limited application in sea state

• Single unit• Direct tailing repositioning, no tailing transportation required• Well suited for mining of thicker layers of material

• Limited sea state, as processing is integrated onboard the dredge

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Introduction / Mining / Processing / Scenarios

Separated functions provide more flexibility

• Opportunity to use trailing suction hopper dredgers

• Operating cycle: process is discontinuous

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Dredging

Transport

Transport

DumpingPumping ashore Rain-bowing

Introduction / Mining / Processing / Scenarios

Choices in mining cycle can create a variation of scenarios

• Similar to the operating cycle of the TSHD, a mining cycle can be setup• For each step in cycle, different options exist

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Mining

Transporttailings

Transport ore

Process plant Concentrate

Source: Van Oord

• TSHD• CSD• WSD

• Floating• Onshore

• TSHD• Barge

Introduction / Mining / Processing / Scenarios

Various scenarios are usually possible. Logistics determine the optimal scenario

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Example 1

Example 2

Example 3

Introduction / Mining / Processing / Scenarios

Finding the optimal requires thorough analysis

• Multiple technology solutions for marine mining are available

• Factors as proximity to shore, wind and wave conditions have a large impact on both the mining and mineral processing options for a mining scenario

• Mining scenarios are a combination of mining, processing and transportation methods selected on a project-to-project basis

• The optimal mining scenario is driven by logistics

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Introduction / Mining / Processing / Scenarios