HPGR in the Iron Ore Industry

Transcription

1 Insights Session HPGR in the Iron Ore Industry Presented by Karri Dorrington, Process Engineer Mineral Engineering Technical Services Pty Ltd PO Box 5778 St Georges Tce WA 6831 P: (+61 8) F: (+61 8) ABN W: E: > M i n e r a l P r o c e s s i n g > E n g i n e e r i n g D e s i g n > T r a i n i n g > S p e c i a l i s t S e r v i c e s

2 DISCLAIMER With respect to all the information contained herein, neither Mineral Engineering Technical Services Pty Ltd, nor any officer, servant, employee, agent or consultant thereof make any representations or give any warranties, expressed or implied, as to the accuracy, reliability or completeness of the information contained herein, including but not limited to opinions, information or advice which may be provided to users of this document. No responsibility is accepted to users of this document for any consequence of relying on the contents hereof. COPYRIGHT Passing of this document to a third party, duplication or re-use of this document, in whole or part, electronically or otherwise, is not permitted without the expressed written consent of Mineral Engineering Technical Services Pty Ltd. ACKNOWLEDGEMENTS This document is a dynamic record of the knowledge and experience of personnel at Mineral Engineering Technical Services. As such it has been built upon over the years and is a collaborative effort by all those involved. We are thankful for the material supplied by and referenced from various equipment manufacturers, vendors, industry research and project partners.

3 Key Attributes Pragmatic, efficient, complete engineering through quality, personalised & exceptional service delivery Working globally since 1988 Dynamic and innovative niche consultancy Dedicated team providing customised service Specialist in mineral processing & engineering projects Unique solution finder A division of Midas Engineering Group

4 Outline What is HPGR? Benefits of HPGRs Iron ore types around the globe HPGR use in the iron ore industry HPGR in iron ore plant design Testwork

5 What is HPGR High Pressure Grinding Rolls (HPGR) Similar to the typical fixed roll crusher Force applied to push one roll towards the fixed roll and raise pressure between the rolls Force on the material mainly compressive Source: Mine Engineer Website (2012) Introduces micro cracking favourable for further comminution Higher reduction ratios than fixed rolls

6 HPGR Reduced power consumption hard ores 10 to 15% Requires secondary crushed feed Reduced BWI Replaces SAG mill-smaller ball mill CAPEX similar 10% moisture in feed Source: Technomine Website (2012)

7 HPGR Source: World of Mining Professionals Website (2012) Source: Weir Minerals Website (2012)

8 HPGR vs Cone Crusher HPGR and Cone Crusher Product

9 Assay, % Magnetic Recoverey, % Benefits to Magnetic Separation HPGR Coarse Cob Cone Coarse Cob HPGR Coarse Cob Cone Coarse Cob 0 MgO Al2O3 SiO2 Fe Wt MgO Al2O3 SiO2 Fe Wt.

10 HPGR vs Cone Crusher More even size distribution Finer size distribution Lower magnetic recovery of gangue minerals such as MgO, Al 2 O 3 and SiO 2 Lower mass recovery Typically a higher iron grade (and other metallics)

11 Iron Ore Types Around the World Canada: Hematite, Magnetite USA: Hematite, Magnetite East Africa: Itabirite, Hematite Russia: Hematite India: LG Itabirite China: LG Hematite Brazil: Itabirite, Hematite South Africa: Hematite, Magnetite Australia: Hematite, Magnetite

12 HPGR in Iron Ore Processing Applied to iron ore industry mainly for regrinding of pellet feed to improve properties in the pelletising process Over time has been applied to other iron ore processes to improve concentrates Australia Magnetite (Karara) Vanadiferous, Titaniferous Magnetite (Future: Mount Peake) South Africa Hematite (Khumani) Brazil Itabirite (Samarco)

13 Karara Project JV project Long life magnetite concentrate operation (30+ years) Low-grade magnetite to produce a high-grade premium concentrate Have issues getting the power efficiency to the SAGs and therefore optimum operating 2011 installation of HPGR Installed downstream of the secondary crusher HPGR significantly lifted feed rates

14 Karara Project

15 Karara Project

16 Mount Peake Project FS Underway Polymetallic ore body Two stage HPGR installed after the secondary crusher Lower operating cost Efficient in producing the required feed size (two stages required) Micro-cracking Reduced mass recovery on coarse cobbing Changes to the process HPGR still beneficial

17 Mount Peake Project (Scoping Study)

18 Khumani Mine High grade hematite deposit in South Africa Formally BKM Project (Bruce, King and Mokaning) 10 Mt export quality iron ore per annum increasing to 16 Mt Civil construction began in 2006 December 2007 first delivery to Bruce primary crusher Late 2007 construction of jigs and HPGR HPGR utilised to reduce middlings particle size

19 Khumani Mine

20 Khumani Mine Single HPGR located after Jigging of the Lump Size reduction from mm to -6.0 mm More efficient than cone crusher Source: International Mining (2008)

21 Samarco Project JV between BHP Billiton and Vale Low grade itabiritic ore Ore Reserve = 451 Mt (wet) as of 2008 Conveyor belts transport the ore to the beneficiation plant, whilst a 396 km slurry pipeline transports the pellet feed to the pellet plant on the coast HPGR prior to grinding, de-sliming and flotation

22 Samarco Project

23 Samarco Project

24 Samarco Project

25 HPGR Plant Design Normally HPGR is located after the primary/secondary crushing Can replace tertiary crushing with SAG mill, where a ball mill is still required Can replace secondary/tertiary/quaternary crushing Not suitable for all ore types High fines/clays lead to impaired comminution High ore competency and abrasiveness will lead to increased wear rates High moisture (>10%) will cause washout of the autogenous layer

26 HPGR vs. SAG Mill Design 1. Original circuit design SAG/AG mills and ball mills (Huckleberry SABC circuit), however very energy intensive and also energy inefficient accounting for ~80% of the overall process plant energy (depending on the overall process) 2. Changes to design lead to HPGR and ball mill circuits, thus lowering the energy consumption costs slightly 3. Further examination, HPGR and stirred mills circuits demonstrated it is technically feasible and showed promising benefits over traditional options Source: E&MJ News (2013)

27 Why Choose HPGR? What are the Drivers? Benefits to downstream processing magnetic separation, flotation, leaching Better energy efficiency lowering costs Replacement of equipment to increase grinding efficiency Willing to investigate with testwork to see if ore is amenable

28 Testwork Prior to selection of HPGR testwork is required Testwork involves: Pressure tests Roll speed tests Roll gap tests Testwork reveals if the ore is amenable to HPGR HPGR settings influence throughput, product size distribution and micro-cracking

29 References Karara Mining Ltd (2013) Energy Efficiency Opportunities KML Expansion Project TNG Limited (2012) Executive Summary Mount Peake Project Pre-Feasibility Study Moore, P (2011) Samarco An Iron Ore Pioneer, International Mining, Dec 2011 Burchardt, E (2013) HPGRs in Hard Rock Mining, Mining Magazine Wang, C., Nadolski, S., Mejia, O., Drozdiak, J., Klein, B (2013) Energy and Cost Comparisons of HPGR-Based Circuits, E&MJ News Morley, C (2010) HPGR-FAQ, Journal of the Southern African Institute of Mining and Metallurgy

30 THANK YOU