SEIS LAGOS THE LARGEST NIOBIUM RESERVE IN THE WORLD IS STILL WAITING TO BE DEVELOPED

 

By Pedro Jacobi

 

In the middle of the Amazon, 60km away from the Venezuelan border and 2km from a local road is the location of the largest Niobium deposit on the Earth.

It is  called Seis Lagos and, believe it or not,  is still waiting for the Brazilian Government’s decision to let miners extract and redistribute its enourmous wealth.

INTRODUCTION

In 1975, during a geological mapping program, CPRM's geologists discovered the remarkable structures of Seis Lagos Alkaline Complex intruded in gneissic terrain. It comprises three different intrusive bodies.

Seis Lagos Property at the Amazonas State is the world’s largest niobium reserve of 2,897Mt @ 2.81% Nb2O5 or 81Mt of Nb2O5 and, possibly, a very large titanium and rare earths deposit.

click the picture to enlarge

The company that acquires this property will be in a position to control the largest niobium reserves in the world, and, likely become the main player in a very important, fast growing, industrial mineral market.

THE ELEMENT

The element niobium (Nb), also named columbium, was discovered in 1802.  Niobium is quite abundant in nature being present in the earth’s crust at the level of 24ppm.  Its fusion point is high at 2468oC.

INDUSTRIAL USES

 Due to its favourable high-temperature strength and good low temperature ductility, niobium has been used as a prime material for the aerospace industries.

 This metal is mostly used in special steels, microalloys and superalloys, automobile industry, nuclear reactors, catalizers, acoustics, electrooptics, high temperature applications, glass manufacture and superconductors.  It is a versatile element which is considered to be the best way of accomplishing many technological goals in a most cost effective way.  Modern niobium technology is replacing the use of several metals such as molybdenum, vanadium, nickel, chromium, copper and titanium in many industrial applications.

 CBMM’s main product is the iron-niobium (65%Nb) alloy which is used as an important element in the high-strength low alloy steels, stainless steels and niobium pentoxide.  Metallic niobium is used together the titanium in a NbTi alloy which is used in an important superconductor material.

THE MINERAL

Pyrochlore (A2-mB2O6(O,OH,F)1-n.pH2O), probably the most abundant niobium mineral, has a extremely variable composition and occurs mainly in carbonatites.  The pyrochlore group also includes betafite (2Ti>Nb+Ta), microlite (Nb+Ta>2Ti) and bariumpyrochlore which is the ore mineral at Araxá.  Columbite is the second most important mineral of niobium and is, mainly, associated to pegmatites and tin bearing granites.

THE HOST ROCKS

Carbonatites are specialised intrusive magmatic rocks which are important sources of niobium, rare earths, titanium, copper, vermiculite and phosphates.

In Brazil the extremely high grades of niobium and titanium in the deposits is a result of an intense leaching of the carbonatite which caused a well developed lateritic profile that can be as deep as 300m.

WORLD RESERVES

Total world reserves of Nb2O5 are estimated at 5.4Mt (excluding the Seis Lagos deposit) being 88% in Brazilian soil.

Known ore reserves, at the most important producing mines, are 464Mt @ 2.5% Nb2O5 at Araxá (Brazil) and 16Mt @ 0.68% Nb2O5 at St-Honoré (Canada).  Other niobium resources are reported from Tapira (179Mt @ 0.67% Nb2O5), Catalão (1.4Mt @ 2.19% Nb2O5) and Salitre (Brazil), Lueshe Lake, Panda Hill, Chilwa Island and Kalubwe (Africa), James Bay, Nemegosenda, Lackner Lake, Oka (6.3Mt @ 0.32% Nb2O5) and Manitou Island in Canada.

MINING

The St Honoré carbonatite complex (Cambior) hosts the most important niobium mine outside Brazil.  This is an underground deposit of low grade (0.67% Nb2O5 ) where mining is executed by means of open stope and pillar.  The mine depth surpasses 400m.

On the other hand, on the Araxá deposit, which belongs to CBMM, and combines the world’s largest reserve (excluding Seis Lagos) and highest grade (2.5% Nb2O5) , the ore is mined by open pit methods.

In Brazil, due to the deep weathering of the carbonatite, blasting is not required and mining costs are much lower than Canada.

METALLURGY

Brazil has a leading position in technological development of special niobium alloys.  The ore, at Araxá, is crushed, concentrated through grinding, magnetic separation, desliming and flotation to 60% Nb2O5 .  The flotation concentrates are then treated in a calcining and leaching plant.  The standard ferroniobium is produced by means of a new metallurgical process improved by CBMM, the aluminothermic reduction.

PRICES

The Niobium price is been stable around 3-7US$/pound as can be seen on the graph.

MAIN MARKETS

There are more than 300 smelters world wide that use niobium in their production:

CONSUMPTION PATTERN FOR NIOBIUM IN THE USA

(US BUREAU OF MINES - 1,000 LBS.)

 

1970

% OF TOTAL 1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

% OF TOTAL 1980

Steel

 

 

 

 

 

 

 

 

 

 

 

 

 

Carbon & HSLA

705

26

821

1874

2180

2291

1796

1882

2350

3011

3178

3204

48

Stainless Steel

522

19

588

644

712

564

379

491

588

805

827

696

10

Full alloy Steel

829

31

789

302

361

511

372

538

584

656

505

476

7

Steel Totals

2056

76

2198

2820

3253

3366

2547

2911

3522

4472

4510

4376

65

Superalloys

472

17

591

665

685

1097

359

423

796

1146

1777

1904

29

Other Alloys

36

1

37

57

67

82

35

50

65

60

32

15

-

Miscellaneous

24

1

51

131

48

78

78

50

20

16

17

7

-

Primary Totals

2588

95

2877

3673

4053

4623

3019

3434

4403

5694

6336

6302

94

Niobium Metal

119

4

115

251

262

161

108

99

190

225

331

346

5

Grand Total

2707

99

2992

3924

4315

4784

3127

3533

4593

5919

6667

6648

99

The main buyers of CBMM’s production are Nippon Steel, Mannesman (Germany), Ilva Spa (Italy), LVT steel (US), Usiminas, Cosipa and Gerdau.

SPECIFIC NIOBIUM CONSUMPTION-KILO/METRIC TON

RAW STEEL PRODUCED

 

1973

1974

1975

1976

1977

1978

1979

USA

0108

0116

0118

0113

0140

0163

0166

Canada

0440

0324

0300

0326

0382

0436

0415

Japan

0068

0100

0142

0147

0136

0133

0138

Austria

0214

0096

0239

0178

0220

0267

0378

Belgium/Luxemburg

0093

0133

0096

0116

0077

0046

0066

France

0104

0130

0201

0168

0190

0193

0207

Germany

0158

0253

0275

0225

0226

0298

0340

Italy

0310

0318

0446

0484

0391

0346

0338

Netherlands

0161

0126

0177

0106

0112

0071

0086

Spain

0056

0052

0113

0118

0071

0088

0086

Sweden

0561

0567

0661

0500

0438

0279

0213

UK

0225

0286

0283

0228

0229

0246

0186

Australia

0091

0094

0127

0128

0137

0171

0185

Brasil

0160

0287

0387

0201

0170

0168

0339

So. Africa

0123

0155

0132

0127

0151

0089

0148

Cambior (Canada) sells to Canada, US and Japan. while Mineração Catalão (Anglo American Corporation) sales are directed mostly to US and Germany.

FUTURE TRENDS AND USES

Niobium  has been promoted, during the last 20 years into a very important component of the world steel industry.  Forecasters are predicting that the consumption will continue growing at the rate of 8-10%.


PREDICTED WORLD HIGH PURITY NIOBIUM METAL CONSUMPTION, 1981-2000

 

 

1981-1985

1986-2000

 

1

NMR and Lab Magnets

25

175

 

2

HEP

40

80

 

3

Computers and Instrumentation

2

18

 

4

Magnetic Separation

1

2

 

5

SMES

4

16

 

6

Levitated trains

-

4

subject to 1985 decision

7

Ship Propulsion

1

9

 

8

Current Limiters

1

4

 

9

Power Transmission

Negligible

70

mainly after 1944

10

Superconducting Generators

1

11

 

11

Fusion

20

230

 

12

MHD

2

65

 

13

Defense

5

50

 

14

Gyrotrons, Isotope Separators

1

3

 

 

Total

103

737

 

SEIS LAGOS, THE LARGEST RESOURCE

In 1975, during a geological mapping programme CPRM’s geologists discovered the remarkable structures of Seis Lagos Alkaline Complex intruded in gneissic terrain.  It comprises three different intrusive bodies.  Only in 1982 that company started a detailed exploration programme.

The main carbonatite is an outstanding topographic feature which stands 300m above the local surface (see picture).

Seis Lagos main structure has a 5km diameter and is situated at the São Gabriel da Cachoeira municipality at the Amazonas State, only 60km away from the Venezuelan border and 2km from a local road.  Seis Lagos is 97km from S. Gabriel port by the Negro River 900km upstream from Manaus.

The carbonatite is, also, characterized by its strong thorium anomaly which peaks at 35.344cps against a 1.300cps local background.

An intense supergene leaching process developed a 250m deep weathering profile.  This is the main reason why this deposit is so rich in niobium (2.81% Nb2O5), titanium and rare earths.

At Seis Lagos the niobium is present in minerals such as niobium-rutile and niobium-brookite together with florencite and crandalite (rare earths).

This unusual mineralogy is a result of the destruction of pyrochlore during the supergene process causing the free niobium to combine with oxigen, forming these oxides.  Niobium may be, also, in the structure of other supergene minerals such as goethite and hematite.

Technological studies have been made by CPRM and, apparently, the ore is amenable to treatment using known technology.  A technical report done by INBRACEL confirms that the use of SAM for direct reduction of Seis Lagos ore will allow the introduction of niobium in common low carbon steels, at a very low price, which may change all the economicity of this metal.

Reserves, calculated by CPRM, after a preliminary drilling programme, are listed below.

RESERVES

ORE (t)

GRADES (Nb2O5) %

Nb2O5 t

Measured

38,376,000

2.85

1,093,716

Indicated

200,640,000

2.40

4,815,360

Inferred

2,658,892,800

2.84

75,512,555

TOTAL

2,897,908,800

2.81

81,431,237

 

Since niobium is associated to titanium it is possible that titanium reserves may be as large as the niobium ones. 

CBMM, THE LARGEST PRODUCER

CBMM is the leading niobium producer of the world and is controlled by the, Brasil Warrant Adm.  De Bens e Empresas LTDA (Moreira Salles Group) with 55% and Molybdenum Corporation (Molycorp) with 45%.

CBMM produces about 65% of the world’s market and 100% of the Brazilian market with annual sales amounting to $150M.  This is one of the most profitable mining companies in Brazil today.

 

 


BOOKS:

 

ABREU, Sylvio Fróes - Recursos Minerais do Brasil, Vol. II, EUSP, Ed. Edgar Blücher Ltda., São Paulo, 1973.

 

REPORTS:

NIOBIUM : proceedings of the International Symposium - International Simposium, Niobium’81, Edited by Harry Stuart, New York, 1984.

CBMM : O Mercado do Nióbio e suas Características, 1985.

ROSKILL Information Services - The Economics of Niobium, fourth edition, London 1983

MAGAZINES:

Revista - Minérios Minerales Extração & Processamento, Ano 18, nº 210, April 1996

PERIODICS:

ALVES, Benedito Paulo - Distrito Nióbio-Titanífero de Tapira, Boletim nº 108, Ministério da Agricultura, Rio de Janeiro, 1960.

GUIMARÃES, Djalma - Relatório sobre a Jazida de Pirocloro de Barreiro, Araxá, Minas Gerais, Boletim nº 103, Ministério da Agricultura, Belo Horizonte, 1957.

PENA, Fernando Ernesto - Perfil Analítico do Pirocloro (nióbio), Boletim nº 18, Ministério das Minas e Energia, DNPM, Brasília, 1989.

 

  Autor: Pedro Jacobi
            

seis lagos ---> 164

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