Title of Publication Edited by TMS (The Minerals, Metals & Materials Society), Year

FALCONDO REVISITED

Mr. Edwin de Jesús Deveaux1 and Mr. Franscisco Geraldo Longo1

1Falconbridge Dominicana, Mining & Development, Box 1343,

Santo Domingo, Dominican Republic

Keywords: Laterites, grade control, mining methods, environment

Abstract After 32 years of operations beneficiating lateritic nickel ore in a fully integrated pyrometallurgical complex, Falconbridge Dominicana (FALCONDO), situated at Bonao and La Vega Provinces, Dominican Republic, has become profitable with one of the lowest nickel grade content processing plants in the world, and literally without any by-product (granulated slag, will be utilized in the future as a post-processing subproduct). To December 2002, mineral reserves were 64.1 million tonnes containing laterite grading as low as 1.15 % Ni when full dilution is applied. At a cut-off grade of 1.20% Ni, the reserves will provide 15-20 years of production. The mineralized thickness over the seven active deposits averages 6 m. Development of very selective and unique mining practices, together with improvements in the process plant, are key to achieving the production goal (30 kt Ni/yr) and to meet the quality standards for the ferronickel produced.

Introduction Falconbridge Dominicana, C. por A. (FALCONDO) has a fully integrated mining and processing complex that produces a ferronickel product containing 38 to 40% Ni. The Company is ISO 14001 (Environmental) certified, being the first company in the country to obtain the certification. The company also is ISO 9000 (Quality) certified. The laterite deposits from which the nickel is extracted are situated in Bonao, Dominican Republic (Figures 1 and 2). A pyrometallurgical process is used to produce ferro-nickel in the form of Ferrocone shapes.

La Vega

LA VEGA PROVINCE

Montaña

MONSEÑOR NOUELPROVINCE

FalcondoPlant

Maimon

Sabana del Puerto

Bonao PiedraBlanca

La Vega

Figure 1: Location of Falconbridge Dominicana Quisqueya No. 1 Concession

Figure 2: FALCONDO Process Plant - Aerial View

FALCONDO'S ACTUAL & FORECAST ORE RESERVES (1)

Projection including dilution tonnages mined and Ore Reserves Additions

10-Year Forecast, excluding Ore Reserve Additions

0

5

10

15

20

25

30

35

40

45

50

55

60

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

(1) 10 Year Forecast Dated Dec. 31st

, 2003. Excludes Possible New Reserves to be Added By Future Reserve Definition Drilling

Mill

ions

dry

tonn

es

Mine PlanningTen-Year Forecast

Projected Diluted Reserves1.20 %Ni Cut - Off

Likely Scenario1.20 %NiCut - Off

1.40 %Ni Cut-Off

Switch to1.20 %Ni Cut-Off

Barmac Reject StockpileAddition

Projected Undiluted Reserves1.20 %Ni Cut - Off

Diluted Reserves

Ore density factors updated

Figure 3: FALCONDO Actual and Forecast Ore Reserves

Summary FALCONDO commenced operations in 1971. Ore reserves at June 2003 were 63,549,000 dry metric tons: 1.19% Ni, at 1.20% Ni cut-off, with a mine life projected of 20 years. The annual nickel production averages over 28,000 metric tons (Figure 3). The richest ore is found in the finer size fractions. Consequently a rubbler plant is provided to separate the fines from the coarse portion. All the material above 2 ½ inches is rejected at the rubbler mill. All the material below 2 ½ inches is fed to the drying plant, where the material is dried from 28% H2O (average) to 18% H2O. The material then passes through 10 mm (3/8 inch) screens in closed circuit with 2 Barmac crushers, one at each line. All the material below 10 mm is ore preparation product, and is stored in 4 silos with 2,500 tonnes capacity each, prior to belt conveying to the process plant The first stage at the process plant is reduction. The oxides are reduced after passing through twelve vertical furnaces arranged in parallel. Finally, the reduced calcine product is melted in two electric furnaces at 1,650 °C where the ferro-nickel metal is separated from the slag. The crude ferro-nickel is refined in a ladle refining system prior to casting into Ferrocone shapes. The slag is discarded to slag dumps. A power plant of 198 MW capacity supplies all the energy needed at the plant. Any excess is sold to the national grid. A 75-km. long pipeline (oleoduct) transports the oil from the Haina port to a topping unit at the plant site. At the topping unit, gasoil and naphtha is produced, the latter being used mainly at the process plant in the vertical reduction furnaces. Water for the process and power plants is provided from a nearby river. This paper describes improvements that have taken place in recent years for ore grade control, methods of ore extraction and haulage and in environmental controls.

Geology Of The Deposit

The FALCONDO nickeliferous laterite deposit was formed by intense tropical weathering of the parent bedrock serpentinized peridotite. Leaching of the more mobile elements was followed by solution transport along preferred structures and permeable pathways and residual concentration on the less mobile elements. In its present state, the FALCONDO nickel laterite deposit can be classified into the following layers: A zone: Chocolate – brown limonite B zone: Ochre – brown limonite C zone: Soft Serpentine D zone: Hard Serpentine E zone: Serpentinized Peridotite F zone: Original rock FALCONDO has utilized each of these layers: A and B (<1.20% Ni) layer is for reforestation purposes; B, C, D and E (occasionally) layers are for mining purposes and E + F material is used for road construction and/or road maintenance. (Table I).

Table I - LATERITE ORE TYPES

Zone Name Color and Texture Composition Other Comments

A Limonite Chocolate-brown Mainly goethite. Some hematite. Normally constitutes the overburden. (Superior Loose and friable. >40%Fe, low nickel, silica and

magnesium. CONTACT: Regular with B zone, and parallels the surface topography.

Laterite) High sulfur and cobalt. USE: Reforestation. May contain commercial %Ni

B Limonite Ochre-brown. Mostly goethite, with some serpentine

minerals. CONTACT: Gradational and irregular with C,D&E.

(Inferior Reddish to yellowish

>35% Fe, lower iron, sulfur and cobalt (still high). USE: Commercial values or reforestation.

Laterite) Brown. Very compact & clayey.

Higher nickel, silica and magnesium.

Some plasticity.

C Soft Serpentine

Vary from green to brown (yellowish or

Green serpentine (lizardite) with goethite close to the contact with B.

Up to 20% by volume of boulders of hard serpentine

reddish) >12%Fe. <14%Fe, when pure (Increases close to contact with D)

(Saprolite) Loose and clayey. Some plasticity.

USE: Commercial values.

D Hard

Serpentine Green <12%Fe. High nickel, silica and

magnesium. 20 - 50% by volume of angular joint blocks (5-25 cm.diameter)

Rocky Low sulfur and cobalt. in a matrix of soft serpentine. USE: Commercial values

E Serpentinized Gray color <10%Fe. Lower %Ni than C & D zones. 50 - 70% by volume of massive angular joint blocks (>25cms diameter).

peridotite Rocky Very high silica and magnesium. Very low sulfur and cobalt.

USE: Commercial values or road construction

F Unaltered Dark gray to black Maximum silica and magnesium values

and minimum nickel, iron, cobalt USE Road construction. The reject (mostly F zone) is used to build and

Ultramafics and sulfur. condition the access roads to the mining fronts.

The zoning description is referred to at FALCONDO as the “Ideal Profile of Laterites”. But the area has been strongly faulted and folded and frequently pockets of one zone can be seen inside another. This is referred to as the “Real Profile of Laterites”. The “peridotite” ultramafic rocks found in the deposit are classified as: • Harzburgite: the most abundant classification. • Dunite: less abundant variety, but is the highest in nickel content. • Serpentinite. which is usually very sheared

Grade Control Grade control is very important to the FALCONDO operation, since the deposit is very heterogeneous. There are several aspects to applied grade control at FALCONDO:

1) Drilling The method now used is rotary percussion with down-the-hole hammer. The particles cut by the drill bit, on the hammer, are pushed to the surface, by air, where they are collected in two metal boxes located around the drill rod string. Samples are “quartered” and placed in bags to be sent to the laboratory for chemical analyses. The three drilling machines are track-mounted with attached air compressors to supply the air for the movement of the machine as well as for the rotary percussion. There are two main types of drill holes: Reserve Estimation Drill Holes: These holes are 50 meters spaced. A sample is taken for each meter drilled. The information gained is used for the estimation of the official reserves. It is also used for the long-term 18 month and 10 year forecasts. Past drilling practice used an Air Flush diamond drill. Production Drill Holes: These holes are spaced at 12.5 meters. A sample is taken every two meters. The information gained is used for grade control while mining. It is also used for short-term forecasts. In the past, production samples were taken every meter. As of November 2003, 58,804 meters has been drilled. The average drilling depth was 14.8 m, with a performance of 10.5 m/hr, and a utilization of 62.9%. In the past, drilling was carried out 24 hours/day and an additional crew was utilized to take channel samples. Samples were quartered only at the laboratory. This practice was changed, as follows: •

•

•

•

The night shift for the drilling crew was eliminated, reducing labour costs without affecting production. The “helper” of the morning crew, while the operator is drilling, is focused on preparing the area to have a good production in the next shift: building access, etc. Now, the drillers take the channel samples, instead of an additional crew.

Outsourcing of the equipment repair and maintenance has increased the mechanical availability. (See Figure 5)

Automatic generation of maps (AUTOCAD) has saved a lot of time. Now, the Drilling Supervisor can spend more time at the field and more people have copies of these maps.

Internal auditing of the sampling procedures is routinely performed.

Projects: Drilling machine with air compressor integrated (Not attachable, but integrated). This is in-progress. Other evaluations Ground Probing Radar (GPR) to detect the contact between the rock and the lateritic soil is being evaluated

Figure 5: Drilling Production and costs after outsourcing

Drilled Meters vs Cost by Drilled Meter. From 1997 to Nov. 2001

$5.8

4

$6.3

3

$4.6

5

$5.4

8

$4.7

7

$-

$10,000.00

$20,000.00

$30,000.00

$40,000.00

$50,000.00

$60,000.00

$70,000.00

$80,000.00

$90,000.00

1997 1998 1999 2000 2001

Costo porMetrosPerforadosMetrosPerforados

From 1991 to sept. 1995 we worked with the same four machines.In august, two new dirll machines and air compressors were acquired

At the end of october of 1998 we started a shutdown until january 1999. We also reduced from 3 to 2 drilling shifts.

December 1999, we started outsourcing the services of repair and maintenance of drilling machines and air compressors.

2) Mine Planning The assays of the drill hole samples are received in the mine planning unit after they are validated at the drilling unit. The information in this database is used to:

Estimate the official ore reserves of the deposit. • • • •

Calculate the ore reserves by benches. Generate geological maps, cross sections, etc…(Figures 6 and 7) Elaborate the mining forecasts. A three-month forecast is generated each month, an 18-month forecast each semester, and a 10-year forecast each year. (Table II)

The main criteria to consider a “mineralized range” in a drill hole are:

1. a mineralized layer more than 1 meter thick (2 meters for the production holes). 2. a grade average equal to or more than 1.20% Ni. 3. a stripping to ore ratio equal or lower than 2:1

Note: Internal dilution is included in the ore reserves.

For easier location at the field, the deposit is divided in 7 “Lomas”, namely Fraser, Guardarraya, Larga, Peguera, Taina, Caribe, and Ortega. These “Lomas” are divided into blocks (150 m x 150 m) usually including 9 ore reserves estimation drill holes.

Figure 6: Production Map

Figure 7: Geological Sections

Table II: Three-month forecast

DECEMBER, 2003 Undiluted Drill Indications

Mining Fronts dry tonnes wet tonnes %Ni %Fe %S Ni/Co Si/Mg %Al %Co %Si %MgF-29 (261) 14,866 19,191 1.49 18.3 0.012 31.0 1.88 2.6 0.048 41.5 22.1G-72 (266) 7,220 9,320 1.49 11.3 0.003 48.1 1.70 1.4 0.031 43.2 25.4L-235 (576) 10,071 13,001 1.57 10.3 0.005 65.4 1.37 2.0 0.024 41.4 30.3L-246 (646) 6,825 8,810 1.50 10.5 0.008 71.4 1.19 1.7 0.021 36.9 30.9L-241 (616) 4,919 6,350 1.46 13.3 0.008 50.3 1.31 2.2 0.029 37.2 28.4L-232 (346) 13,793 17,805 1.40 17.4 0.010 37.8 1.45 3.8 0.037 35.6 24.6P-338 (566) 13,622 17,585 1.58 16.0 0.021 39.5 1.32 3.5 0.040 33.5 25.3P-306 (536) 12,510 16,149 1.74 13.1 0.011 58.0 1.55 2.6 0.030 37.5 24.2T-402 (556) 11,159 14,405 1.64 19.0 0.022 34.9 1.37 2.6 0.047 30.5 22.2T-428 (521) 13,247 17,101 1.75 10.5 0.008 72.9 1.36 1.2 0.024 37.9 27.8

T-448 (441+436) 12,803 16,527 1.92 09.7 0.007 91.4 1.53 1.5 0.021 43.2 28.2T-406 (100) 10,391 13,414 1.30 16.0 0.020 32.5 1.64 2.3 0.040 37.8 23.0

C-562 (219@205)

19,346 24,974 1.57 14.0 0.010 49.1 1.61 2.4 0.032 41.7 25.9

C-1608 (282+275)

9,132 11,788 1.38 18.7 0.007 28.2 2.28 1.7 0.049 40.2 17.6

C-573 (233+226) 7,945 10,256 1.48 21.1 0.008 30.2 1.83 1.7 0.049 36.8 20.1C-605 (240) 8,748 11,293 1.43 24.4 0.010 24.7 1.96 7.3 0.058 28.4 14.5C-566 (170) 18,625 24,043 1.66 09.4 0.005 87.4 1.69 1.4 0.019 44.6 26.4C-726 (373) 5,239 6,763 1.39 15.1 0.012 25.7 1.80 3.0 0.054 40.0 22.2C-726 (366) 16,842 21,741 1.45 16.7 0.010 31.5 1.88 3.3 0.046 39.1 20.8C-509 (177) 13,049 16,845 1.70 12.1 0.009 68.0 1.80 1.9 0.025 42.2 23.4C-588 (100) 10,000 12,909 1.32 14.5 0.012 34.7 1.67 2.6 0.038 37.2 22.3C-518 (100) 9,102 11,750 1.33 14.6 0.009 40.3 1.71 2.1 0.033 37.3 21.8C-604 (233) 10,622 13,712 1.55 22.7 0.016 28.2 2.05 5.8 0.055 26.9 13.1O-844 (450) 3,042 3,927 1.54 16.8 0.016 36.7 1.39 4.1 0.042 32.2 23.1O-805 (275) 17,890 23,094 1.60 11.0 0.007 55.2 1.36 1.8 0.029 38.4 28.2O-824 (219) 48,202 62,224 1.45 18.8 0.019 27.4 1.60 3.8 0.053 35.1 21.9

FIRST MONTH 329,210 424,977 1.53 15.3 0.012 40.1 1.60 2.8 0.038 37.7 23.6Plant Feed 1.18 Rock 53%

(Fully Diluted) Serpentine 36% Limonite 11%

Improvements in mine planning Originally, the mineralized range was manually calculated and then introduced to the computer (IBM System 36) for ore reserves calculation. FALCONDO introduced the following changes in the mine planning function:

• At the beginning of the 1990s the Geological Information System (SIG, in Spanish) was

created. SIG is an “in-house” developed software, in FoxPro database. From this database, the mineralized range is calculated and updated automatically, as well as the ore reserves. Geological maps, cross sections, etc. are also generated automatically with this program, in AutoCAD base.

•

•

•

•

Recently, the FoxPro database was transferred to an Oracle database, with web base, giving more security, reliability and flexibility to the system.

Calculation of “Potential ore reserves” in a lower level is now automatically integrated to the ore reserves. Before, it was not possible to calculate the ore reserves of a lower mineralized range with potential of becoming part of the ore reserves if, for some reason, some of the material on top was removed resulting in a lower elevation of the “new surface

Determining the density by type of ore (A, B, C, D, E and F) and application in mine planning is now routine. Before, an average of the densities of the different types of ore was used.

FALCONDO applies the Canadian regulations of estimating and reporting ore reserves with 2 geologists affiliated to the Association of Professional Geoscientists of Ontario (APGO).

Projects • GPS is now routinely used to update the elevations and receive a quick feedback to produce

accurate mining forecasts. Other evaluations • A Geostatistical system to estimate reserves was evaluated. At present, the “in-house "

developed software is still being used. 3) Grade Control At The Field Approximately, every 3 days the filling of a 50,000 metric tons capacity bay (ore storage) is forecast. At each shift, there are 2 geological technicians in the field, who control the quality of the ore mined at the mining fronts. To do that, they use visual control and information from the geological maps and “bay forecast” (drill hole information) and channel samples. There is also a senior geological technician who supervises the geological technicians, by giving them all the tools and information needed, and who is also responsible for making the “bay readjustment”. The “bay readjustment” consists of calculating the tonnages and percentages of each element needed to finish the bay with all the parameters as required by the process plant. The technicians select the appropriate available mining fronts and must include adequate and realistic tonnages. The geological technicians receive “in-house” training to visually estimate the nickel content and other elements such as % Fe and SiO2/MgO ratio. They do that based on the physical characteristics of the ore, mainly the color, texture, weight and friability. The geological technicians make the decisions on ore or waste during the grade control at the mining fronts and give instructions to the truck drivers where the material is to be hauled from amongst several possibilities:

•

•

•

to the dump slip. If it is mineable ore (>1.20% Ni) and fits the required chemical parameters at that moment,

to waste stockpiles,

to low grade ore stockpiles,

•

•

to limonite stockpile, or

to stripping stockpiles

Note: If it is mineable ore, but is not required at the moment, it is left at the mining front. A key factor for decision-making in grade control is the sampling at the face of the mining front. “Urgent Samples” are sent to the laboratory when quick feedback is required of the nickel content of a material that visually appears to have low nickel content. Urgent samples are taken on the occasion when there are doubts about other elements such as % Fe, SiO2/MgO. Each truck, filled with ore, is weighed and grab-sampled. A composite sample is sent to the laboratory each 4 hours (two per shift). The sampler gives feedback to the shovel operators about the weight of the truck, although most of the mining trucks have weightometers integrated into the machine. The sampler also ensures that the truck number and weight, operator name, etc. are registered on the computer. Improvements in grade control

FALCONDO introduced the following changes in the grade control function:

•

•

•

•

•

•

•

•

•

More extensive formal training to the geological technicians

Grade control training to the shovel operators.

Low-grade ore stockpiles now form part of the plant feed. Presently, mining is being carried out from 1.20 to 1.39% Ni stockpiles. This material was previously stockpiled when the mine cut-off was 1.40% Ni.

Detection and mining of pockets of ore not included in the ore reserves (20 millions tonnes from 1971 to 1996, 14 millions tonnes from 1997 to 2002, were mined over what was estimated in the ore reserves).

Increase of internal dilution and low-grade ore, extracted from the mining fronts. 19.1% internal dilution plus low-grade ore has been extracted (November 2003).

Geological Production System (SPG in Spanish) computerized system allows the geological technician to quickly handle more information. This has reduced the time needed at the office and now the senior geological technician is investing this additional time in supervising activities.

Operational efficiency was gained because the mine no longer requires a geological technician and a mine supervisor by area (Peguera, Caribe and Ortega). Instead there are “Jefes de Turno” (shift bosses), who are in charge of the grade control, as well as of everything related with the operations at their areas.

Lowering the bench height decreases the dilution in the mining activity as an example from 10 m to 7 m and then to 5 m. A 7 m bench height is maintained where the mineralized layer is thicker (Loma Caribe and Loma Ortega).

Internal audits are routinely conducted of the sampling procedures, as well as to the process of filling a truck with ore.

Projects FALCONDO has the following ongoing projects in the grade control function: •

•

•

•

•

• • • • • • • • •

Projects aimed at decreasing the percentage of waste reaching the dump slip.

Laptop computers, integrated to the network so that the geological technicians are able to see all the information (including maps) in the field. Presently, they are taking with them hard copies with all that information.

Portable X-ray analyzer (X-met), with the objective of providing quick in-the-field analytical results of the nickel and iron content of the material at the bench.

Ore Extraction And Haulage

Mining is by direct excavation with front shovel and backhoe. No blasting is used in the mining activities. The mining benches are 5 m. high, except Loma Caribe and Loma Ortega (7 m). There are two main mining methods:

Mining with front shovel: A hydraulic front excavator cuts the ore directly from the mining front and loads the off-highway trucks (55- and 90-tonne capacity). A bulldozer is used to condition the mining fronts, to lower the bench height and to break the rocks at the benches. This method is better for the visual control, since the geological technician has an excellent view of the mineralized face. This method is commonly used when the information indicates a good distribution of the ore all along the forecasted area, and when there is ore from top to bottom at the bench. Mining with backhoe: A backhoe cuts the ore directly from the lower bench and fills the trucks. A bulldozer is used to feed the ore to the shovel.

This method is better to mine selectively some isolated pockets of ore. Besides, to open a new bench with backhoe, no ramp construction is needed, which makes this option very useful when going to a lower bench is needed quickly. To haul the material from Loma Ortega (48 km) the ore is sent in 50-tonne off - highway trucks to a “Transfer Area”, where the 45-tonne capacity highway trucks are filled with a front loader and the ore hauled to the plant. As of November 2003 our heavy equipment fleet consists of:

23 Off-Highway trucks 10 Hydraulic excavators 20 Bulldozers 3 Front Loaders 20 Highway Trucks 20 Trailers 3 Graders 5 Water Trucks 2 Lowboys

Improvements in mine operation FALCONDO introduced the following changes in the mine operation: •

•

•

•

•

•

•

Increasing the trucks from 40- and 55-tonne capacity to 90-tonne capacity.

Increasing the capacity of the shovels from 4.5 m3 to 5.6 m3 buckets.

Increasing the size of the dozers from D-7 and D-8 to D-9 CAT bulldozers.

Production Engineering System (SIP in Spanish) computerized system has helped the efficiency of clerks and samplers and is an excellent source of timely information.

Since 2001 blasting has been used occasionally to increase the speed of the development activities.

Surveying is now conducted with total stations, instead of the original surveying transits

Staff now uses conventional GPS to update the topography at the mining fronts.

Projects FALCONDO has the following ongoing projects in the mine operation: •

•

•

•

•

Mining the dryers reject stockpiles. This material was stockpiled when previously mining at higher cut-off grades.

Evaluating the use of GPS (Global Positioning System) by the surveying team to update how advancement is progressing at the mining fronts.

Environment FALCONDO is an ISO 14001 Certified Company. The main environmental issues that are controlled are:

Reclamation and Reforestation When an area is totally mined- out, the promontories are cut and holes are filled to create a smooth surface topography. Then, waste material is deposited in 7-meter benches. When a bench is finished, high iron stripping material is placed on top. Then, waste is deposited in the upper 7-meter bench. Simultaneously, in the recently finished benches, grass is grown (Estrella Africana). When the area is finished trees are grown, mainly Casuarina Equisestifolia and Acacia Mangium. Sediment Control Presently, there are 14 earth sediment dams, which guarantee that the sediments suspended in the running waters are retained inside FALCONDO properties and are not going to the surrounding waters. There are “permeable” and “not permeable” dams. In streams with permanent water running we build permeable dams. But in streams where only the rainwater runs we build “not permeable” dams, especially if there is agriculture or cattle land.

Dust Control Five water trucks (2 in Loma Ortega) are used to water the access roads.

Comparison With Other Operations

FALCONDO’s operation is characterized as a low-cost nickel producer, even though fuel costs are 70 % of total production cost in operating the pyrometallurgical process. Table III compares other nickel laterite pyrometallurgical operations in the world:

Table III: Current Pyrometallurgical Laterite Operations

Costs in US$/lb of Ni Company Operation Country Reserves2

(Mt) Ni% %Ni

recov./pay.Mining

Cash

C1

Oper. C2

Tcash C3

Margin

PT Inco 3 Soroawko Indonesia 97.0 1.69 141.1 0.27 1.40 2.00 2.17 0.86

BHP Billiton Cerro Matoso Colombia 46.9 1.93 110.8 0.11 1.35 1.67 1.95 0.81 PT Aneka Tambang Pomalaa Indonesia 21.2 2.42 23.0 0.25 1.75 1.90 1.99 0.80

Codemin Niquelandia Brazil 5.4 1.37 14.4 0.22 1.58 1.82 2.10 0.50 FALCONDO Bonao Dominican Rep. 60.7 1.14 60.7 0.24 2.32 2.48 2.51 0.33 Anglo American PLC Loma de Níquel Venezuela 41.4 4.48 43.0 0.12 1.63 2.12 2.45 0.24

SLN Doniambo New Caledonia 54.0 2.70 125.7 0.39 1 2.21 2.38 2.53 0.11

Larco Larymna Greece 48.0 1.05 43.0 0.43 2.30 2.85 3.02 -0.17

(1) Includes other costs (2) Year 2001 database (3) Co is also produced as subproduct Source: Brook Hunt Associated-2003 From the table the key features of FALCONDO’s economical operations for the 2001 recording period by Brook Hunt are: • •

•

•

Excepting Larco’s operations, FALCONDO is the third lowest margin producer After PT Inco, FALCONDO has the second largest published ore reserves and the second lowest %Ni content Of those operations, FALCONDO achieved the fourth lowest Ni recovery

Conclusions FALCONDO is a relatively high-cost operation. And the reasons for that are:

Pyrometallurgical Plant. It consumes a lot of energy, making the process very expensive. • Ore Reserves. After 32 years of operation the nickel content and tonnages have decreased. • Location/Logistics. Because it is located on an island, high levels of supplies and

inventories are kept and many varied ancillary facilities had to be built to guarantee some services; for examples, a power plant, topping unit, oleoduct, water distribution system, laboratory.

• No by-products. Different from hydrometallurgical operations that are producing cobalt as a by-product, FALCONDO only produces nickel.

The main goal at FALCONDO is to lower the operational costs. To attain this goal, the company is focused on operating at the highest efficiency. The Mine department has achieved this higher efficiency through: •

• • • • • •

Providing more efficient equipment and technology, thus helping to reduce the manpower requirements. Optimizing the ore reserves administration. Adding new reserves. Improving computer the system and programs. Quality systems. Outsourcing repair and maintenance services. Training.

FALCONDO, despite the high fuel costs (U.S$1.92/pound at November 2003) and low-grade nickel, is a profitable operation. It is still a very important ferronickel producer supported by efficient personnel.

References

1. Corrigan, James; Lithgow, Enrique; Uceda, Diógenes. Falconbridge Dominicana environmental experience in Dominican Republic. March, 2004.

2. Brook Hunt Associated-2003. Brook Hunt Cost Study 2002.

3. Deveaux, Edwin. Operación Minera en Loma Ortega, La Vega. Minería 98 : III Seminario sobre el sector minero. 1998.

4. Deveaux, Edwin; Frías, José R.; Longo, Francisco. Dominican laterite production : Mining to metal. Laterite Workshop. March, 1995.

5. Lithgow, E.W. Geology, mining and metallurgy of the Dominican Republic nickeliferous laterite ores.

6. Longo, Francisco. Características metalogenéticas de las lateritas niquelíferas de la República Dominicana. Primer congreso de geología y ciencias afines de la Hispaniola.

7. Moore, Chester. Geology and operations of Falconbridge Dominicana C. por A., Dominican Republic. February 2001.

8. SME of AIME. International Laterite Symposium, NY. 1979.

9. 9TH Caribbean Geological Conference. 1980