visit by national parks & nature conservation authority

I

VISIT BY

NATIONAL PARKS & NATURE

CONSERVATION AUTHORITY

\ NATIONAL PARKS & NATURE CONSERVATION AUTHORITY

ENEABBA VISIT - THURSDAY 12 MARCH 1992

9.45am-10.00am

10.00am

10.30am-12.30pm

12.30pm- 1.30pm

1.30pm- 3.00pm

AGENDA

Arrive

Morning tea and Site Introduction

Tour

1. Allied Eneabba Rehabilitation - early 1980's

past rehabilitation practices mining of rehabilitation areas

2. 1992 Rehabilitation Site

topsoil handling practices mulching

1991 Rehabilitation

current rehabilitation practices 1991 monitoring results

3. South Mine Dredge

mining practice mining sequence - topsoil stripping, mining tailings

4. Accedens Lookout

total area disturbed total area rehabilitated 4 year old rehabilitation comparison mined/not mined vegetation

5. Nursery

seed collection practices nursery propagation programmes

6. 1985 Rehabilitation

monitoring techniques

Lunch

Discussions

1. Dieback 2. Completion Criteria 3. Research Projects 4. Other

PARTICIPANTS

National Parks & Nature Conservation Authority

Arthur McComb Libby Mattiske Marion Blackwell Steve Wilke Rory Neal Malcolm Trudgen Roger Underwood Keiran McNamara Drew Haswell

Accompanying Staff

Frank Batini David Rose David Gardner

AMC Mineral Sands Ltd

Steve Gilman Max Leggett Graeme O'Grady Roger Wilson Neil McMulkin

Alan Luscombe Fiona Nicholls Tony Petersen

Jane Elkington

Chairman Deputy Chairperson

Operations Manager Production Superintendent Environmental Superintendent Environmental Co-ordinator - Land Use Acting Environmental Co-ordinator - Horticulture

Mining Manager Manager Environmental Affairs Senior Environmentalist

Consultant Botanist

AMC MINERAL SANDS LTD ENEABBA OPERATIONS

OPERATIONS MANAGER

MANAGER ENVIRONMENTAL AFFAIRS

SENIOR ENVIRONMENTALIST

STAFF

STEVE GILMAN

A Metallugist with 20 years experience in a variety of mining and extractive operations, Australian, African and American. First involved with Mineral Sands at Narngulu and Eneabba in 1976 and was part of the team introducing Dredge Mining to Eneabba.

FIONA NICHOLLS

Joined AMC in January 1990 located in Perth Office. Fiona completed an Honours Degree in Natural Resources at the University of New England, Armidale, N.S.W. in 1981. In recent years was in the Environmental Management of the exploration and production aspects of the Oil Industry in South Australia.

TONY PETERSON

Completed a Bachelor of Science Degree in 1977 and a Post Graduate Diploma in Environmental Impact Assessment in 1991. Has worked in the field of environmental management specialising in rehabilitation for the Uranium, Gold, Bauxite and Coal mining industries.

Joined AMC in 1990 and is located in Perth Office having responsibility for rehabilitaiton at all AMC's Sites in W.A.

ENVIRONMENTAL SUPERINTENDENT GRAEME O'GRADY

ENVIRONMENTAL CO-ORDINATOR

ACTING ENVIRONMENTAL CO-ORDINATOR

Holder of Bachelor of Business degree from W.A.Institute of Technology. Joined AMC in January 1987 after 8 years managing a rural property. Appointed to current position in October, 1989.

ROGER WILSON

Completed Certificate of Horticulture at Mount Lawley Tech. while working for the Kings Park Board.

After landscaping for 3 years joined AMC Mineral Sands Ltd as P ro pa g a ti on Off i c e r in 19 8 3 to develop and implement seed collection and propagation programmes. Reappointed to th i s p o s it io n in Au gu s t , 1 9 8 8 .

NEIL McMULKIN

Responsible for propagation activities.

Has completed Certificate of Horticulture at Bently Technical College, Perth in 1985.

Joined AMC in 1989 after gaining wide experience revegetating Coastal Sites.

Appointed to current position in February 1989.

NATIONAL PARKS & NATURE CONSERVATION AUTHORITY


TOUR STOP ONE

REHABILITATION BY ALLIED ENEABBA

This area (Block 81LS) was rehabilitated in 1981 by Allied Eneabba Pty Ltd. Monitoring has obtained the following results:

Density Year

Geosporous Bradys porous Total Richness Cover

1986 2.92 0.42 3.34 4.82 14.3

1987 6.49 0.07 6.56 4.56 9.9

1988 6.31 1.44 7.75 4.66 11. 9

1989 12.25 14.29 26.54 7.45 22.7

1990 8.29 4.09 12.38 4.87 14.2

1991 6.92 3.70 10.62 5.14 29.7

Note that monitoring does not record the presence of the dominant shrub Acacia blakelyii. This species was sown at high rates by Allied Eneabba Pty Ltd but is now sown at only 15 g/ha when required.

Rehabilitation techniques employed in these areas generally used less mulch and more topsoil than that used at Eneabba by AMC. Mulching was often done in strips whilst topsoil return depths were unsustainable at the rates used here. Irrigation was also used on some rehabilitation areas in contrast to present methods.

MINING OF REHABILITATION

It is possible that some areas will be re-mined as modern mining techniques can economically recover minerals which occur at low concentrations.

Re-mining would allow older areas to be rehabilitated using improved techniques which have been developed by AMC Mineral Sands Ltd following years of research and development.



TOUR STOP TWO

1992 REHABILITATION

This area is currently being rehabilitated. The dredge tailings have been contoured and topsoil has been respread . A layer of locally harvested mulch has been applied to provide surface stabilisation, seed sources and organic matter. Sowing of locally collected native seed will occur before April. Shrubs which have been raised in the site nursery will be planted into this area in the 1993 winter.

A detailed account of the current rehabilitation techniques used at Eneabba is attached.

Two important features of these techniques are topsoil handling and mulching.

Topsoil is stripped and re-applied in two cuts. This aids establishment of propagules present in the surface of the soil. Topsoil which is salvaged and cannot be re-spread directly onto prepared ground is stored in stockpiles. Regular audits are conducted to ensure that sufficient topsoil exists to recover all disturbed areas.

Mulching harvests vegetation from areas to be mined and from firebreaks around CALM reserves . The material collected from one hectare is respread over about one hectare. Wherever possible, mulch is returned to similar topographies from where it was harvested. Mulch has been shown to contribute around three quarters of the total seed source in the rehabilitation programme .

1991 REHABILITATION

This area (Block 91MS) was established last year and so has one seasons's growth. Monitoring in November 1991 recorded the following results:

Density Year


1991 MS 8.12 3. 60 11.72 7.92 0.70

1991 3.37 5.56 8.93 4.40 0.58 Average

This block has performed significantly better than the average of all blocks established last year. In particular, the number of geospores is well above average. This block was able to receive first and second cut topsoil which had not been stockpiled.

CONT'D

MONITORING

Annual monitoring of the rehabilitation commenced in 1984.

After a comparative research project, stratified random sampling was used to collect quantitative data in the undisturbed vegetation for the pre-mining survey and now forms the basis of monitoring programmes providing data on both the undisturbed vegetation and the rehabilitated areas.

Since the development of the Electronic Botanical Data Management System (EBDMS) in 1986, data has been directly entered into a field computer and then downloaded onto a mainframe system for further processing.

Data processing enables selection of categories based on the life form characteristics of Raunkaier and by family, genus and species. The selected categories of species richness, plant density, and cover values can be listed for each rehabilitated area.

Native vegetation recorded in the rehabilitated areas are categorised as either bradysporous or geosporous species.

The bradyspores, defined as a plant which disperses its seed gradually is used here to describe the plants contributed from mulch. Geospores represent the species germinating from seed stored in the topsoil. Added seed is a combination of these two categories.

Quantitative monitoring data collected from rehabilitated areas have recorded the effect changes in establishment techniques have made towards improving the first year rehabilitation results.

1

REHABILITATION TECHNIQUES

The basic techniques employed can be considered as contouring, topsoiling, stabilisation, establishment, tree planting and rehabilitation maintenance.

Experimental work has shown that all seeding must be completed by the end of May. This deadline therefore di ct ates the start of earthworks operations such as contouring and topsoiling to ensure the completion of subsequent operations.

Contouring

The basic landform is re-established as part of the ongoing mining operations. Tailings are pumped from the concentrator to the disposal area where landforms similar to the pre-mining situation are developed.

Consideration is given to final drainage patterns, degree of slope and final elevation.

If tailings placement finishes in an area between December and April it can be rehabilitated directly . However, if the area is finished between May and November, the surface requires stabilisation with a cover crop. This crop is killed before topsoil is spread on the area by either ploughing in the crop or using herbicides.

A swamp dozer is used to enhance any drainage patterns and also detects any soft spots where scrapers would not be able to travel.

Topsoiling

Generally topsoil spreading commences in late January/early February and must be finished by the end of April.

The spreading of topsoil is normally carried out by scrapers except in those areas where the sub-strata is too soft to allow access. For these areas a bund of topsoil is placed adjacent to the soft spot and pushed by swamp dozer over the area. This operation is avoided wherever pos~ible as it leads to greater soil compaction, higher costs and higher us·age of the topsoil resource.

Topsoil is spread in the reverse order to which it was removed. Topsoil stripping is done in two cuts - first cut is the surface 50mm whilst the second cut is taken to a significant colour change which is usually around 200mm. On re:spreading, the second cut is followed by the first cut and leads to a total topsoil depth of around 120mm.

Where possible topsoil is spread over a similar landform from which it originated. If topsoil is spread from stockpiles of different ages, it is spread in strips from alternate stockpiles. This achieves some blending. Further blending is achieved with cultivation.

Cultivation is carried out using tractor drawn tynes which reach a depth of only 30-40mm. This operation is carried out approximately on contour and increases surface roughness which reduces wind erosion and provides seed collection niches.

2

On steep slopes, contour banks have been constructed to control water run-off.

To minimise loss and degradation of the first cut topsoil, the operation is managed so that stabilisation occurs as soon as possible after topsoil is spread. The area of first cut topsoil spread but not yet stabilised is also kept to a minimum.

Stabilisation

Stabilisation of the surface is required to combat wind erosion and its ~-damaging effects on small germinants. It is achieved by covering the surface with mulch.

The mulch is produced by harvesting vegetation from areas to be mined using a modified flail mower. Driven by a power take-off and mounted on a threepoint linkage, the tractor drawn mower cuts to about 100mm above the ground. Occasional stumps or "trees" {3m maximum height) are avoided. Vegetation is reduced to segments less than 100mm.

Harvested material is blown in a chute from the mower to a "Krone" manure spreader which is also tractor drawn alongside the mower. The "Krone" is a laige trailer with a PTO driven mnving floor which helps to spread the mulch evenly over the surface.

Mulch from one hectare of heath is collected and spread on about one hectare of prepared ground. Wherever possible, mulch is returned to topographic localities and vegetation communities which are similar to the areas from which the mulch was harvested. This is because the mulch not only provides surf ace cover, but al so represents a major component in the revegetat ion process. It is thought to contribute about three quarters of the total seed source for the rehabilitation programme.

Tri a 1 s have been conducted using chemical stabilisers both al one and in conjunction with mulch and have shown promising results. Their use may help reduce the loss of small germinants from saltating sand particles .

Establishment

Vegetation is established from seed and by planting seedlings. Native seed is supplied from several sources: seeds stored on branches and harvested by the mulching operation; locally collected seeds of selected species which are broadcast by Vicon spreader and by Leggate sprearing of selected larger seeded species. Seeds will also be contained in the topsoil.

Tailings which will not be topsoiled for some time are sown with a cover crop of cereal rye {20kg/ha) and fertiliser {150kg/ha) using a seed drill.

Areas which have been topsoiled and mulched are sown with a mixture of cover crop and fertiliser. The rates used are:

Sudax 1.25 kg per hectare Oats 1.00 kg per hectare Acacia pulchella .015 kg per hectare Acacia blakelyii . 015 kg per hectare Superphosphate plus Cu, Zn, Mo 50 kg per hectare

3

This is achieved by using a seed drill whose discs have been removed. This mix is applied twice on t~e perimeter of blocks to provide protection from winds.

Following application of the cover crop, locallay collected seed is cleaned, mixed with fertiliser and spread with a Vicon spinner. Larger seeded species are distributed using a Leggate spear.

A range of different seed mixes are prepared and these are summarised on Table xx.

The Environmental Department at Eneabba collected over 400kg of cleaned mature seed in 1991 from 76 different species. This seed was also used to propogate ~-seedlings in a nursery.

Tree Planting

Over 70,000 seedlings are raised in the nursery every year and planted in rehabilitation which is one year old.

Planted species supplement the .revegetation achieved through seeding and germination of soil stored species. The planting stock are species which have proved difficult to return from seed but are important components of the communities. Banksias form the majority of the planting stock for this reason.

Planting is carried out selectively by topography: Banksia attenuata on or near the crests; Banksia candolleana and Banksia menziessii on the slopes; Banksia qrossa, Banksia candolleana and zanthorrhea sp on the flats.

Seedlings are planted as soon as soil moisture conditions allow and have traditionally been planted with a fertiliser pellet, however this practice has been discontinued.

Another important component in helping to provide a stable surface for revegetation is the construction of artificial mesh fences. Their construction is held over until establishment is completed.

!

Mesh fences provide the following benefits: they reduce wind velocity at the surface; they limit vehicle access to rehabilitation areas; and they prevent degradation at the perimeter of rehabilitated areas particularly along roads or service corridors.

Fences are erected along the perimeter of rehabilitation blocks as well as at regular intervals in the rehabilitation according to the direction of prevailing and storm winds and the surrounding topography.

The standard fence for the area is 1.8m high and is constructed using star pickets, plain fencing wire and 50% knitted black shade cloth; The cloth has a 100mm flap at the bottom on which earth is placed to prevent wind erosion under the fence.

\ .\

I

4

Maintenance

Maintenance begins with a dressing of 50kg/ha of nitrogenous fertiliser to first year blocks applied in late winter or at the first sign of N deficiency.

Rehabilitated areas are constantly reviewed for weed infestations and disease outbreaks. Appropriate remedial actions are taken as required.

Monitoring of the developing communities provides valuable information on what specific maintenance measures may assist in the development process. Several areas have received maintenance mulching. Other options which can be considered are selective thinning, controlled low temperature burns, in situ mulching and specialised fertiliser applications.

Review

The techniques for rehabilitation at Eneabba are under constant review. Contributions by every member of the Environmental Department are encouraged from tractor drivers through to research scientists. The techniques employed are recorded every year as a reference document to ensure that this wisdom is not lost or misinterpreted.

Recognition must be given to the role of the research programme in continuing to improve the rehabilitation performance. Rehabilitation and research are now inextricably linked in similar nexus as the chicken and the egg.

. I

5

AMC MINERAL SANDS LTD ENEABBA OPERATIONS

SEEDING AND PLANT MIXES USED FOR REHABILITATION

TABLE N° XX

N° of Rate Species g/ha

SEEDING Dune Crests

Seeding mix 14 2,880 Leggate Spear mix 5 141

Dune Swales Seeding mix 48 3,890 Leggate Spear mix 13 224

Wet Areas Seeding mix 18 1,313 Leggate Spear mix 1 628

Maintenance Seeding mix 7 375

Cover crop - tailings 1 20kg Cover crop - topsoil 4 2,280 Fertiliser 100kg

PLANTING

Dune Crests 6 920 Dune Slopes 6 920 Dune Swales 4 920 Wet Areas 4 1,800

Area - ,

ha 1991

69 69

67 67

10 10

12

138 138

26 32 8 3

DREDGE MINING



TOUR STOP THREE

The Eneabba South dredge is typical of AMC Mineral Sands Ltd dredge mining operations. AMC has many years of experience with dredge mining and rehabilitation on the east coast of Australia.

The attached Fact Sheet explains further the main aspects of mining and processing mineral sands.

This dredge is to shut down in March for approximately one year due to current market demands.



TOUR STOP FOUR

An overview of the Eneabba operations can be obtained from this site which is on the side of the Gin Gin Scarp looking west over the Eneabba plain. The enclosed map shows these physiographic features in a regional context.

The orebodies are present as a series of nearly parallel areas lying roughly north-south and represent ancient coastlines. The main features of the mine and orebodies are illustrated on the enclosed map entitled "Life of Mine Plan - Eneabba".

Information on the geology and historical development of the orebodies is also available on an enclosed sheet.

Some statistics on mining and rehabilitation at Eneabba:

Total Area Distured Total Area Rehabilitated Average Annual Rehabilitation Average Annual Expenditure Number of Full Time Rehabilitation Personnnel

1636 ha 984 ha 100 ha

1,400,000 $ 13

The rehabilitation directly in front is Block 88EN and contains heath species of the lateritic soils in constrast to Block 91MS which contains species of the deep dune sands.

Block 88EN has developed thus:

Density Year


1988 1.47 7.41 8.88 4.06 0.57

1989 0. 77 5.23 6.01 3.12 29.29

1990 1. 75 5.29 7.06 3.91 18.19

1991 Not monitored

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Life Of Mine Plan Eneabba

~Mineral Sands· Ltd

Bv.s S-ro/o B I~ ::::--._ \

NORTH CONCENTRATOR

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-----.-----:;:

LOCALITY PLAN

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~ PROVED RESERVES

11jlj1jljl 1!1!1!1!1 1

m MINED OUT

MINERALISED - DRILLING INCOMPLETE

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/ SOUTH CONCENTRATOR

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DREDGE PATH WEST DREDGE

,,:t . ' DRAWN - K.McNEIL - 4/4/91

IND/AN

OCEAN

SCALE 0 50 km L....-__ ..__ __ ..__ __ .__ _ _,.__ _ __, 10 20 30 40

18

Figure 3-2 PHYSIOGRAPHIC REGIONS

OF THE NORTHERN KWONGAN (Mir Pt,,yfanl ., • 1976)

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LEGEND

Major Road

Minor Road

Study Area

Existing National Park, Nature Reserve

Existing "other" Conservation Reserve

Proposed National Park, · ' · Nature Rese\'Ve

r-:-~~-':I a;;;;;;;~:,:; Lesueur Area

Physiographic Region Boundary

LOCALITY MAP

G!'RAlOTON •

* Lesuair Are.a

PERTH •

GEOLOGY OF THE DEPOSIT

The deposit in the Eneabba area, variously estimated -from 30-40,000,000 tonnes of heavy mineral is believed to have been formed in the early Pleistocene geological period, betw~en l million and 350,000 years ago.

The mineral sands were deposited along an ancient coastline at the base of the GinGin scarp, a prominent erosion cliff within the Perth sedimentary basin. The origin of the minerals was the hinterland of sediments, deposited during the Mesozoic era (100 - 200 million years ago).

Deposition was assisted by the predominant north-south long-shore drift and a substantial, northward facing bay.

HISTORICAL DEVELOPMENT AT ENEABBA

Jennings Mining was the first company to open up operations in the Eneabba region on the nort~ end of the field in the mid 1970's. They were followed by Western Titanium Ltd, and Allied Eneabba Ltd who operated at the _south end of the field.

Associated Minerals Consolidated merged with Western Titanium in 1978 and later purchased the Jennings deposits. The AMC mine was commissioned in June 1976 and has produced consistently since that date.

In 1986 AMC's parent Company, Renison Goldfields Consolidated Ltd, took over Allied Eneabba's operation and the Eneabba field is now the largest mineral sand mine in the world .

The workforce of about 250 is accommodated in two single me~'s quarters and 150 houses, 60 of which are situated on the coast at Leeman.

AMC operates mining, concentrating and processing facilities at Eneabba. Some mined concentrate is dried and railed to a second processing plant at Narngulu near Geraldton.



TOUR STOP FIVE

This area serves as the main facility for the Environmental Department containing seed shed, nursery, machinery sheds, workshop, laboratory, amenities and office.

It is a functional area in a central location servicing the needs of 13 full time personnel rising to 25 with seasonal labour during peak periods.

The seed shed accommodates the processing of approximately 400 kilos of native seed from 70 species each year. Seed collection concentrates on those species not readily returned from mulch .

The nursery has the capacity to propagate 70,000 seedlings of those plants important in the vegetation communities and not readily returned from seed, such as Banksias and Xanthorrhoeas. Accreditation from the Nursery Industry Association as a disease free producer of plants is a major aim for the nursery staff.

The rehabilitation process recognises the importance of wet area habitats on the mine site as they are limited in number in the natural environment .

Accordingly, special efforts are being made to grow nursery stock for the reconstruction of wet areas in drainage lines.

A copy of the seeds collected in 1990-91 is enclosed .

Every year, twenty species are selected to have seed germination tr.i al s conducted both on site and at Curtin University. This provides valuable data on yearly variations of a particular species and which species give good returns for the labour involved.

Nursery practices are continually being re-assessed seeking improved results. Last year, experiments were conducted to assess improved potting mixes and fertilising regimes.

3411Q~-010889 190989 040889 461189 491289 600190 720390 301089 650390 160889 660390 251089 220989 371189 331189 431189 710390 380989 380989 361189 401189 271089 140889 010789 130889 231089 120989 020789 030789 030789 100789 321189 591289 581289 441189 210989 080889 090889 070889 060889 261089 451289 281089 281089 640390 170889 620390

690390 501090 180989 471189 610390 571289 391189 240989

1989-90 SEED LIST Quantity

Acacia pulchella Actinostrobus acuminatus Actinostrobus pyramidalis Allocasuarina humilis Allocasuarina sp. Anigosanthos manglesii Anigosanthos pulcherrimus Astroloma xerophyllum Banksia attenuata Banksia candolleana Basnksia hookeriana Banksia lanata Banksia menziesii Beaufortia elegans Burchardia umbellata Conospermum incurvurn Conospermum triplinervurn Conostephiurn pendulum Conostylis neosymosa (1) Conostylis neosymosa (2) Darwinia rieildiana Darwinia speciosa Ecdiocolea rnonostachya Erernaea acutifolia Eremaea beaufotioides Eremaea violaceae Eucalyptu~ drumrnondii Eucalyptus jucunda Eucalyptu~ macrocarpa Eucalyptus todtiana (1) Eucalyptus todtiana (2) Eucalyptus tetragona Geleznowia verrucosa Grevillea :polybotrya Grevillea :shuttleworthiana Haemodorum simplex Hakea c~nt_,i.o_leana Hakea conchifolia Hakea corymbosa Hakea flabellifolia Hakea incrassata Hakea smilacifolia Lachnostachya eriostachya Laxmania omnifertilis (1) Laxmania omnifertilis (2) Leptospermum erebescens Leptospermum spinescens Lomandra preisii Lysinema ciliatum Macrozarnia reidleii Macropedia fulginosa Melalueca acerosa Neurachne al~pecoides Nuytsia floribunda Pileantus filforrnus Ptilotus polystachyus Petrophile drummondii

4221. 8 11135.6

493.2 127.7

1096.0 529.4

60.5 837.0

4798.7 594 . 3

5513.9 2984.5 1089.9 2047.5

630.8 5700.0

21750.0 305.0 392.9

11700.0 634.6 172.1

10389.7 3464.7

12589.3 1870.1 2063.3

41.8 998.4 314.8

1186.5 439.2

1458.0 2126.5 3405.0

826.7 226.6 118.3 257.6 742.8 625.4

26.4 4700.0 103.6 111. 8 518.0 549.5

11100.0 492.0

5058.7 294.9

2267.5 932.5

1504.4 5100.0 3400.0 4400.0

•.• I 2

491189 551189 110889 531289 311189 531189 561289 551289 541289 680390 670390 670390 670390 200989

Pirnelia leucantha Restio sp.

-2-

Strangea cynanchicarpa Thryptomene prolifera Tersonia brevipes Thysanotus patersonii Stirlingia latifolia Verticordia browi:tii Verticordia densifolia Verticordia nitens Xanthorrhoea reflexa (1) Xanthorrhoea reflexa (2) Xanthorrhpea reflexa (3) Xylomel4angustifolium

TOTAL 66 SPECIES=

483.5 116.8

56.5 5800.0

350.9 96.75

74000.0 6000.0 5300.0

32100.0 2600.0 . 2500.0

16700.0 4350.7

308013.8



TOUR STOP SIX

This area was rehabilitated in 1985 and provides an opportunity to see the maturing rehabilitation and consider the legislative requirements for mining at Eneabba.

Completion criteria were negotiated between AMC and the Department of State Development, Mines Department, Department of Conservation and Land Management and the Environmental Protection Authority. The following criteria were agreed:

Pl ant Density Species Richness Canopy Cover

12 plants per square metre 6 species per sqare metre

32 percent

A report on environmental management activities is submitted every year to the Government with a major review submitted for approval every three years. An annual inspection is also undertaken.

This area (White Pit or 858N) has developed thus:

Density Year

Geosporous Bradysporous Total Richness Cover

1985 2.2 3 .1 5.3 3.5 <l

1986

1987 4.1 8.4 12.5 6.2 10

1988 3.2 5.0 8.2 6.2 19

1989 4.7 6.2 10.9 6.1 18

1990 Not monitored

The results obtained from 1991 monitoring data is summarised by the attached three graphs. These will be further discussed whilst considering Completion Criteria in the afternoon.

Vertebrate and invertebrate monitoring is al so conducted to assess faunal return, seasonality and food requirements. The attached comparative histogram summarises the return of species diversity to the rehabilitated areas by invertebrates to date.

1991 REHABILITATION MONITORING SUMMARY

The table below summarises the average of the results for the blocks monitored in 1991 in relation to the year of sowing:

No of Average Average Average Blocks Density in Density Species Average

Year No of Monitored 1st Year in Richness % Sown Blocks in 1991 Rehab 1991 in 1991 Cover

1981 7 2 0.75 9.15 3.75 35.44

1982 9 7 I. 77 5.75 2.90 24.42

1983 8 2 3.77 7.58 3.39 16.94

1984 6 2 0. 77 7.41 4.24 17. 72

1985 8 8 4.03 6.0 3.36 16.97

1986 5 2 6.94 11.32 4.49 16.97

1987 13 13 7.08 9.80 4.33 16.69

1988 8 1 6.38 6.24 3.58 16.21

1989 17 17 8.88 7.39 3.59 15.28

1990 8 8 6.55 6.54 3.64 3.77

1991 11 11 8.97 8.97 4.40 I. 74

Comments in relation to data presented in the above table and represented graphically:

This is the average of all the monitoring done in 1991. Not a 11 blocks were man i to red in accordance with AMC' s man i tori ng programme.

The density figures show the significant increase in density over time of blocks. The much higher first year results for the recent years indicate the high potential for reaching the target result.

The species richness figures initially look consistent over the different age blocks. However, these figures need to be interpreted similarly to the density figures where the initial species richness for the 1981 block was significantly less than it is now. (Unfortunately it was not possible to provide these figures in the short time available).

The percentage cover figure indicates the trend discussed in the AMIC paper (Appendix 4) that cover increases with time. Even the 1981 block with its very low initial density figures has acceptable cover values in the 10 years.

14

12

rn I

Plants 0t

/m2 61 4 I

2

I ~ I ~

AVERAGE RESULTS OF 1991

MONITORING DATA - DENSITY ~ Average Density in

1st Year Rehab

1.2] Average Density in 1991 (plants/m2)

+ Interim Completion Criteria - Standard

0 I "'Yi~"-.) I '>'Y'L"-"~ I L»),1~,._::,J I """~"-~ I t,,»l~~ I L»"JL'>-~ I h-»),l~ ;,wi I ~ D,.'U) , J;').;»l~ :,0.J I ffi)l t>....'u::11 1 tu,'\'jL'>-',".u I 19B1 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

AIEHS YEAR SOWN

B

6

NO SPECIES 4

/M2

2


MONITORING DATA - NO SPECIES/M2 ~ Average Species

Richness in 1991 (no species/m2)

+ Interim Completion Criteria - Standard

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AEPEC

1986

YEAR SOWN 1987 1988 1989 1990 1991

Average

% Cover

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25

20

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MONITORING DATA - AVERAGE% COVER

fS! Average X Cover

+Interim Completion Criteria - Standard

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YEAR SOWN

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COMPARATIVE HISTOGRAM OF SPECIES IN EACH AREA 1988/91

Blattodea Orthoptera Hemiptera (Cockroaches) (Grasshoppers) (Bugs)

Scarabaeidae (Herbivorous Beetles)

Carabidae Curculionidae Hymenoptera (Predator (Weevils) (Wasps/Bees) Beetles)

Formicidae (Ants)

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WHAT IS THE NSDWP?

The Northern Sandplains Dieback Working Party is a group formed to promote the study of dieback (Phytophthora spp.) in the Northern Sandplains to enable the implementation of effective research, management and educational programmes.

Our objectives are:

• To share knowledge and experience qn dieback management.

• To promote a high standard of operational hygiene by setting the example for others.

• To promote and support dieback education programmes for regional land users and the general public.

• To share <:_nd co-ordinate training effort.

• To utilise media and other extension opportunities.

• To promote and support projects that contribute to the understanding and management of dieback.

WHY DO A SURVEY?

The discovery by CALM of dieback near Cataby in 1986 alerted people to its existence in the region. Restricting the spread of the disease is the best defence until a practical cure is found for infected plants. A regional survey was therefore essential in assessing the potential risk to the valuable plants of the area.

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WHAT IS DIEBACK?

Dieback is an introduced disease which kills plants. The Phytophthora fungus lives in the soil and infects roots of plants starving them of nutrients and water. There is no known cure for the disease at present. Some plants infected by the fungus die very quickly. Banksias, dryandras and hakeas are some examples. Other plants are affected over years and appear to die back gradually- hence the name "die back". Resistant plants include marri, wandoo, river red gum and sedges.

HOW DOES IT SPREAD?

Dieback is usually spread by the movement of soil through human activity. Once introduced the fungus spreads throughout drains, swamps and streams. When soil or water that is infected with dieback moves downhill or downstream it carries the fungus with it.

WHY DOES IT MATTER?

Dieback is a real threat to many plants in the Northern Sandplains. Many of these are not found any where else in the world. As well as being an important biological resource they also help support local industries such as beekeeping, wildflower harvesting and cultivation, tourism and recreation. These industries are worth millions of dollars each year.

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WHAT DID THE SURVEY FIND?

A map showing all the dieback infections · recorded to date is shown overleaf. It clearly illustrates that diebackis already widespread in the region, but most infections are sm9ll and l1JCalised.

The following diagram summarises the other main findings of the survey:

• Wet areas (swamps, drains) are most at risk

• Road verges ·and drains may harbour the fungus.

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• • •

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IMPACT AND TOPOGRAPHIC POSITIONS AT DIEBACK INFECTED SITES

/

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'

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* P. nicotianae var. parasitica

SEALED ROAD

- - - - UNSEALED ROAD

I

1 I I I _J // KILOMETRES

-i -~!--, ~ _ __,,"-__ /

----~ 10 5 0 10 20 30 40 50 60 70 80 90 . 100

t~ I I I I I

Wongonderrah Nature Reserve

• 11

,-1-8&.::,,._-

Base map by Land Information Branch, Department of Conservation and Land Management, September 1989

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APPROXIMATE LOCATIONS OF KNOWN DIEBACK INFECTIONS, WITH SPECIES AND SITE NUMBERS 1990.

Mineral sands

Who needs them?

Everyone. Every day.

• • •

No-one in the western world spends a day without using mineral sands. Paint on the walls, colour in clothing, printing inks, ceramics in the bathroom or kitchen, televisions, computers, make-up, medicines -all use mineral sands products.

TITANIUM

The foundation for the industry is the international market for high grade titanium dioxide pigment. Ilmenite and rutile contain titanium dioxide, one of the whitest substances currently known to man.

The unique opaque and reflective qualities of titanium dioxide have given colours a richness rarely seen before the modern pigment process was developed in 1918. The characteristics of titanium dioxide create an effective ultra-violet screen providing a replacement for unsafe lead oxides previously used in paints. The result is a safer and more durable protective coating than any of the traditional alternatives. Apart from paint, titanium dioxide pigment appears in inks, fabrics, plastics, food and cosmetics.

The titanium minerals, rutile and ilmenite, are also used to produce flux for welding rods, abrasives for industry and titanium metal for aerospace, surgical implants and equipment for food processing and water desalination plants.

r

-ZIRCON

One of the toughest materials in existence zircon has an exciting future in the production of advanced ceramics. Processed to zirconia or zirconium zircon forms the basis for heat resistant and 'durable components in engines, computers, bearings and a wide range of industrial and domestic products.

Traditionally, the most important uses for zircon include resistant linings for foundries and refractories and glazes for ceramics. However, modern applications cover a huge variety of domestic and industrial uses from insulated clothing and ball-point pens to spacecraft components .

MONAZITE

Once a low value by-product of mineral sands mining, monazite has become an important source of rare earth oxides essential to many high technology industries. Televisions, sophisticated electronics, robots, computers, and scientific and research equipment use rare earths from monazite in manufacture and quality control. Rare earths are also used in energy efficient lighting, X-ray screens, fibre optics, pain killing elements and chemical catalysts. Products from monazite are used in metallurgy, flints, feroalloys, glass polishing jewellery, phosphors, fuel cells, refractories, lamp mantles and welding electrodes.

-

8 AMC FACT SHEET 1~1

~

AMC The world's largest mineral sands producer

Geraldton • • Narngulu

eEneabba

PERTH•

eCapel

•DARWIN

• Pine Creek

AMC MINERAL SANDS LTD A division of the RGC Group

AMC is the mineral sands division of Renison Goldfields Consolidated Limited, which is an Australian based international mining group. In addition to mineral sands the RGC Group produces tin in Tasmania and Indonesia, gold in the Northern Territory, New South Wales and Papua New Guinea, copper in Tasmania and is developing a coal mine in New South Wales. RGC conducts extensive exploration programmes in Australia and overseas.

Other RGC Group activities include metal and minerals trading, portfolio investment, oil investment, afforestation and timber milling. RGC employs more than 4,000 people.

Market leadership and technical excellence have played a major role in the emergence of AMC as the world's

largest producer of heavy mineral sands.

AMC heavy minerals which are mostly exported are worth in excess of $300 million a year. The products, rutile, synthetic rutile, ilmenite, zircon and monazite are used in the pigment, ceramics, electronics and hundreds of other industrial and domestic industries.

AMC employs more than 800 people at its current operations in Western Australia and in Florida, USA.

The Company has three mining operations at Eneabba and one at Capel.

The maJonty of the Eneabba ilmenite is used as feedstock for AMC's synthetic rutile plants at Narngulu and Capel. The company is currently upgrading its Narngulu

capacity to 260,000 tonnes a year . The heavy mineral production from

AMC's Australian mines is mostly exported through the ports of Geraldton, Bunbury and Fremantle. Some synthetic rutile is sold locally as pigment feedstock.

The Green Cove Springs operation produces rutile, zircon, ilmenite, leucoxene and monazite at its mine and processing plant. These minerals are mostly distributed within the United States of America.

The company's international BRISBANE• operations are taking on increasing significance following successful exploration in Virginia, USA. AMC is presently conducting a feasibility study for a mineral sands mine, separating plant and synthetic rutile plant at this location.

Namara @

RGC GROUP ACTIVITIES

• Mineral sands

• Gold

• Copper

• Tin

@ Coal

•ADELAIDE Lucky Draw • •SYDNEY

• MELBOURNE

Q t r 1 Renison Bell ueens own•

•HOBART

0 • Wau Bangka Is.

The AMC story

e Virginia

eareen Cove Springs

AMC's operations began in 1947 at Southport on Queensland's Gold Coast, with the mining of rutile for use as a welding flux. The Company's founder, Joseph Pinter, had designed the first economic electrostatic separator, which is important equipment for separating mineral sands concentrates.

First, as Associated Minerals Pty Ltd and later -from 1953 - as Associated Minerals Consolidated Ltd, AMC's operations and interests expanded with the fortunes of the mineral sands industry. The industry's growth years were prompted by the demand for rutile as a flux coating on welding rods and later by the popularity of safe and effective titanium dioxide pigments, as a substitute for unsafe lead-based paints.

In 1962, Zircon Rutile Pty Ltd, which was Australia's first operating mineral sands company at Byron Bay in 1934, became a subsidiary of AMC. During the same year the AMC group of companies became a subsidiary of Consolidated Goldfields Australia Limited (CGFA).

The merger in 1977 of AMC with Western Titanium Ltd, a Western Australian producer with operations in Capel and Eneabba, made the company the largest mineral sands producer in Australia. Western Titanium was the company which had earlier developed the innovative synthetic rutile process which added significant value to the locally produced ilmenite.

In 1980, AMC expanded beyond its operations on the east and west coast of Australia with the acquisition of a mineral sands operation at Green Cove Springs, in Florida.

Renison Goldfields Consolidated Limited then emerged as a diversified international mining group following the merger in 1981 of CGFA and its listed subsidiary companies which included AMC.

AMC ceased mining on Australia's east coast following the depletion of available reserves in 1985.

In 1986, RGC acquired Allied Eneabba Ltd, consolidating the extensive mineral sands resource of the Eneabba region into the one operation. This move has enabled the Eneabba field to be developed more rationally.

AMC Occupational Health & Safety

• To provide all employees with a safe and healthy working environment at all times.

• To provide all employees with the information and training needed to avoid occupational diseases, injuries, property loss or damage, and to encourage employee participation in maintaining high standards of resource control.

• To ensure that the operations of the company are harmoniously integrated with the local community and natural resources in both the long and short term.

• That resource control is the responsibility of every employee, and is an integral part of all operations.

• That every management level shall be responsible and accountable for all the resources under its control.

• That suitably trained resource control personnel shall be employed to provide a service to the individual company operations.

• That the company's resource control programme shall be pursued with vigour and supported by adequate resources.

• To regularly review, and amend where necessary, this policy and the resource control programme.

General Manager, 9th July, 1986.

8 AMC FACT SHEET 1~1

Policy

--5 -

~ - --- - --

Operations Group Principles

1. We are a team. We must treat each other with trust and respect.

2. We believe that quality decisions and commitment are achieved by the participation of those significantly affected.

3. We believe employees are valuable and contribute to our success and that our future depends on continued education and self improvement.

4. A quality performance in all activities is paramount.

5. We will establish a climate of continual improvement and encourage creativity and innovation.

6. We make quality decisions based on facts and logic.

7. We will encourage decisions to be made at the lowest appropriate level.

8. We believe that feedback is essential and we accept constructive criticism.

9. We will seek to eliminate barriers to optimal performance.

10. We will strive for a safe, secure, healthy working environment.

AMC Environmental Policy

Mission Statement It is the objective of AMC to continue to supply the world with mineral sands

whilst protecting our valuable environment for future generations, thereby achieving a balance between conservation and development.

Policy The policy of AMC is to continue to evolve and maintain high standards of

environmental management throughout its operations, thereby exceeding appropriate government and community expectations.

Principles 1. Sound environmental management is the responsibility of every employee,

and is an integral part of all operations.

2. Appropriate baseline studies are conducted as part of the environmental planning of operations.

3. Areas disturbed by operations are to be minimised at all times.

4. The best practicable technology for managing emissions and wastes are implemented to meet appropriate current and anticipated environmental standards .

5. We continue research and development of our environmental technology and share that technology, and its achievements with others for the community's benefit.

6. We continue to monitor the environmental effects of our operations so as to assess, review and enhance our environmental management programmes.

7. The visual impact of our operations is minimised by implementing high standards of housekeeping.

8. As our operations are a temporary use of land, high standards of rehabilitation are implemented to sustain optimum post operational land use for maximum benefit to the community.

9. Our operations are integrated into the communitv and open communications are fostered.

10. Our environmental policy is pursued with vigour, supported by adequate resources, and reviewed and amended where necessary.

General Manager, December, 1989.

ENEABBA WEST

eSOUTH MINE

PERTH

Eneabba Mineral Sands Field

The Eneabba mineral field is approximately 300 kilometres north of Perth and 30 kilometres from the coast.

Like most mineral sands reserves , the deposits are predominantly grains of acid igneous rock , washed to the ocean and concentrated by wave action on ancient beaches. The Eneabba West deposits were laid down over a million years ago.

The ore has a low grade ( or low concentration) of approximately 3.1 per cent heavy mineral contained in quartz sand .

However an important advantage of the Eneabba field is the fact that its ilmenite is ideal for processing to synthetic rutile and subsequently to titanium dioxide pigment. Most ilmenite - the predominant mineral in all WA mineral sands deposits - is ultimately used for pigment production.

The Eneabba West mine site has an estimated life of 13 years. However, it is hoped that continued exploration and improved production technology will mean that new deposits in the region will be brought on-stream and extend the economic life of this major mineral sands region.

-

8 1~1

-

Eneabba West

AMC FACT SHEET

- ... _ .... ~ .... ...... --

~ ------=========:::====~~--==------=== ------ --··

Eneabba West

The Eneabba West mining project is one of the world's most important mineral sands developments. The venture brings total production from the extensive Eneabba mineral sands field to more than 35 million tonnes a year - the largest heavy mineral sands mining operation in the world.

By introducing modern large scale dredge mining to the Eneabba region, AMC has improved the outlook for the mineral sands industry in Western Australia. The Eneabba West Project, with its 3,000 tonnes per hour bucketwheel dredge, completes the transition to a new era in West Australian mineral sands production.

The new venture has enabled the expansion of AMC's synthetic rutile production - adding value to the State's mineral resources.

As part of AMC's comprehensive development strategy, Eneabba West has become a vital component of this region's multi million dollar a year mineral sands industry, which employs more than 550 people in Eneabba and Geraldton .

MINING IN THE REGION

The Eneabba area was first mined for mineral sands in 1975 and AMC became involved with the area in 1977 following the merger with Western Titanium Ltd.

The mining was initially conducted using bulldozers, feeders and conveyor systems. But as the ore grades declined, dredging became an economic necessity to further develop the Eneabh:i 111ineral sands field.

AMC, with many years experience in dredge mining on Australia's east coast, began investigating ways to adapt dredging technology to suit Eneabba conditions.

The incentive to switch to dredging technology was based on the prospect of more efficient energy use by reducing the distance the ore is transported to the separator. When conditions permit, dredges are able to process higher volumes of ore at reduced cost, allowing the mining of low grade deposits.

AMC introduced dredge mining to Eneabba in 1988 . By using robust dredges, efficient screening, improved clay handling and water management the Company proved that dredge mining could be successful for inland deposits. The result is a more stable long term industry for the Mid West.

A MAJOR COMMITMENT

Developing the Eneabba West Project has involved a capital investment of $120 million to build the world's largest underwater bucketwheel dredge, a floating concentrator and a separation plant at Narngulu, Gerald ton.

The dredge - Amanda II - was constructed in the Netherlands. The 3,000 tonnes per hour electric powered dredge is designed to operate to a depth of 16 metres. The area of the pond in which the dredge and concentrator operates is ten hectares.

The 2,400 tonne per hour concentrator designed in Australia is essentially a network of spiral gravity separators concentrating the ore from three per cent heavy mineral to a concentrate containing 90 per cent heavy minerals.

After a secondary processing stage the concentrat<:: is railed to Narngulu, near Geraldton 150 kilometres from the mine site, where it is separated into its individual constituent minerals ilmenite, rutile, zircon and monazite.

Ilmenite and rutile are valued for their titanium dioxide content which is used as white pigment in the paint, paper, plastics, printing and rubber industries, and as the source for titanium metal used in the aerospace and medical

industries. Zircon is widely used in the refractory, foundry and ceramics industry and future uses lie in the development of advanced ceramics. Monazite is a source of rare earths, used in electronics and other high technology products.

ENVIRONMENTAL MANAGEMENT

The Eneabba West operation is on agricultural land bordered by two nature reserves. Part of the land has been cleared for agriculture and the remaining natural vegetation has been grazed. Native vegetation of the district is mostly low woody heath containing a complex array of plant species. Some of the land has been salt affected by clearing for agriculture.

AMC has already achieved an outstanding environmental record at Eneabba - one of the most difficult rehabilitation sites in Australia due to low fertility soils and an arid climate. The aim of rehabilitation at Eneabba has been to establish a self-sustaining ecosystem on mined land. The programme's success has involved the integration of rehabilitation with mine management.

The programme begins when rehabilitation teams move in ahead of the mining operation to conduct plant surveys and collect seed or mulch before the existing vegetation is cleared.

Following mining, the rehabilitation process involves contouring to re-establish the landscape and drainage patterns, spreading of topsoil stockpiled prior to mining, surface stabilisation, direct seeding and maintenance. Heavy emphasis is placed on seed collection and direct seeding of the native species. The Company supplements the natural regeneration with an additional 70,000 native plants a year produced in its own nursery.

At Eneabba West, AMC aims to maximise the productive use of the land after mining with a combination of deep rooted agricultural crops and native vegetation. A range of techniques will be applied to control or reduce salinity of the land.

SAFETY

AMC mine s ite s ha ve achieved an unprecedented safety record during operation.

The Company's Eneabba mining operation achieved a world first when it was awarded fi ve star safety status by the International Institute of Loss Control Management for the fifth year in succession in 1990.

Narngulu Minerals, the Geraldton-based processing operation for Eneabba mine sites, has matched the Company's mining achievements by passing the 1,000 injury free days milestone in July 1990.

The same standards have been achieved at Eneabba West Project construction sites at both Eneabba and Narngulu . No lost time injury during the 11 month project construction period was recorded .

The AMC safety programme is built on extensive workforce involvement in policy and administration . Workforce-based committees have made site safety a priority in the Company's operations.

100

50

o....._.-.. ______ ___. __ __. _ __. _ __..___.L-_,__

198 1/ 82 82/ 83 83/ 84 84/ 85 85/ 86 86/ 87 87/ 88 88/ 89 89/ 90

LOST TIME (per million man-hours)

I ~ .• • / • • • • , • •

.•.. -· ~ ,_ r -.. - -:.._ ,

SYNTHETIC

The process

RUTILE

REDUCED ILMENITE

SYNTHETIC RUTILE

Synthetic rutile production begins with the mixing of ilmenite, coal and sulphur in a rotating kiln. The effect of

\ being heated to temperatures of more than 1,200 degrees Celsius reduces the iron oxides to metallic iron.

This reduced ilmenite is mixed with water and aerated to rust the iron grains from within the ilmenite leaving synthetic rutile and iron oxide. The synthetic rutile is separated from the iron oxide before being cleaned in a sulphuric acid leach and washing plant.

Waste gases from the process are cleaned before discharge to the atmosphere and liquid wastes are neutralised and stored in evaporation dams. At Capel, the treated water is suitable to discharge to the AMC Wetlands Centre - a wetland ecosystem for the conservation of waterbirds.

The synthetic rutile process turns ilmenite into synthetic rutile, a refined and valuable pigment plant feedstock - similar to natural rutile .

Ilmenite is a mixture of iron oxide and titanium dioxide (approximately 60 per cent). Titanium dioxide forms one of the whitest substances known to man - and the most effective and safe pigment.

The objective of the synthetic rutile process is the removal of iron oxides from ilmenite, leaving a product containing more than 90 per cent titanium dioxide which is close to the titanium dioxide content of natural rutile.

The technology for producing synthetic rutile .._...,...,.., was developed by Western Titanium (an AMC

s bsidiary) at Capel in 1970 in conjunction with the Government Chemical Laboratories . The process uses coal mined at Collie as a reducing agent and energy source to remove the iron and other impurities from the ilmenite.

The achievement has become more important in an environment-conscious world where pigment producers are phasing out the traditional sulphate route pigment production which used raw ilmenite as feedstock. The sulphate route process for pigment production involved the disposal of significant quantities of iron-acid effluent. The modern chloride route for pigment production -based on rutile as a feedstock - has no real effluent disposal problems. However, as natural rutile is scarce, the development of a rutile substitute was important to the world pigment industry.

This technology advantage has been one of the major factors in the growth of the mineral sands industry in WA dur · ng the 1980 .

recycled water

AMC FACT SHEET

Mining and Processing

Australia produces more than half the world's mineral sands used in colouring agents, ceramics and thousands of domestic and industrial products. One of the major reasons for Australia's success in the international marketplace has been the industry's development of efficient technology for production and processing. As the world's largest mineral sands producer, AMC has made a major contribution to the development of mining, separation and processing techniques .

EXPLORATION

The mining story begins years in advance of any production with the work of exploration geologists in proving new deposits . Exploration is the key to a mining company's long term future.

Geologists first select exploration targets on the basis of observations regarding topography, soil types and likely geological history. Areas which show some potential are drilled on a widely spaced grid to identify the occurrence and concentration of any valuable minerals . The five centimetre diameter drill holes are easily rehabilitated and leave no trace of the exploration work. Sites which produce encouraging results are drilled on a more closely spaced grid to produce samples for laboratory testing and computer analysis, and to establish the variability across and along the mineral occurrence.

MINING

Once a deposit has been confirmed, a mine plan is formulated for its development and rehabilitation.

AMC uses two main mining methods:

• Dredging, which involves working in artificial ponds and pumping ore to floating concentrators

• Dry mmmg which involves the use of scrapers and a bucketwheel excavator and conveyor systems to collect the ore for processing in land-based concentrators.

Dredging is the more economical, requiring less energy per tonne mined, allowing lower grades of ore to be extracted .

Dry mining is necessary in areas where the deposits are shallow, complex, too hard, or consists of a number of unconnected orebodies.

Dredging is the only practical method of mining when the deposit lies below the natural water table.

The next stage of concentrating the minerals is the same for both methods. The ore is fed into a screening system to remove any rocks before being fed into spiral gravity concentrators which separate the heavy mineral

ILMENITE

ORE

Non-magnetic

~

ore from the lighter sands. This results in a concentrate of 90 per cent heavy mineral.

The basic principles of mineral separation are simple and depend on gravity.

The deposits are formed because the valuable minerals are heavier than other constituents of coastal sands. Grains of igneous rock, carried by rivers to the ocean, are separated by wave action, which concentrates the heavy minerals by washing away the light quartz sand.

After mining, the materials are separated in the same way. Man-made spiral water-courses or cones can concentrate the heavy minerals by washing quartz and other light sands to the outside of the spiral, leaving the heavy minerals to settle on the inside. By repeating this process a number of times, the concentrate can be significantly upgraded.

Non-Conductors Zircon/Monazite

Magnetic Non-magnetic

~ ~ RUTILE MONAZITE ZIRCON

REHABILITATION

Both mmmg methods use the concept of progressive mining and rehabilitation. Rehabilitation teams continously gather native seeds and plant material in advance of the mine path to use in the subsequent revegetation programme. Mobile equipment is used to clear the land and preserve the topsoil for future use in rehabilitation.

Most of the ore ( over 95 per cent) is returned to the mine excavation as tailings and is used to progressively re-establish the original land forms . The contoured tailings are covered with topsoil for revegetation - usually with native plants or pasture, depending on the original land use. As the heavy minerals are chemically inert, their removal from the soil does not inhibit successful rehabilitation.

MINERAL PROCESSING

The mineral concentrate is treated using the electrical conductivity and magnetic properties of the minerals to separate ilmenite, rutile, zircon and monazite.

Ilmenite and rutile are conductors, reacting to high voltage electrical charges, while zircon and monazite are non-conductors. Therefore the result of this process is to separate the ilmenite and rutile from zircon and monazite.

The next step is magnetic separation.

Ilmenite, which is magnetic, is separated from the non magnetic rutile with high intensity magnets, while the same process is used to extract monazite which is magnetic, from zircon.

Dry separation which relies on the physical characteristics of the minerals means that the process does not cause damage to the environment.

AMC developed fully enclosed separation equipment to eliminate most dust from the dry separation plants. Most other mineral sands companies are now adopting this technology.

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