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STUDY, EVALUATION AND RESERVES ASSESSMENT OF TITANOMAGNITITE ORE, GABAL WADHAIT AREA, SOUTH EASTERN

DESERT, EGYPT

Dr/ Mosad Hashim El-Baragah

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• The Gabal Wadhait titanomagnetite ore occur in the south- eastern part of the Eastern Desert of Egypt.

• The present work deals with an area of about 9.4 km2 and lies between:- lat. 22 ْ 32 10 ً - 22 ْ 34 37 N and long. 34 ْ 59 57 ً - 35 ْ 01 َ 15 ًE

Geological map of Gabal Wadhait Area (after Nasr et al., 2000)

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TM of the area under investigation

G. Wadhait

W. Wadhait

W. Kamowib

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• Nasr et al., (2000), reported three titanomagnetite occurrences associated with mafic-ultramafic intrusions. These occurrences are south Gabal Korab Kansi, south Gabal Akab El Negum and northwest Wadi Abu Fas.

• Shaaban et al., (2002), estimated the geological ore reserves

of massive titanomagnetite as 1.8 million metric tons and disseminated titanomagnetite as 2.5 million metric tons.

► Previous Work

• Abdel Megid et al., (1996) and Oweiss et al., (1996), were first discovered and, recorded of titaniferous iron ore at south Gabal Korab Kansi.

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• Mansour and Makhlouf (2003), mentioned that the geophysical exploration carried out on the ores revealed that, Gabal Wadhait titanomagnetite ore bands are extending about 100 m to 120 m subsurface and the titanomagnetite massive ore reserves are calculated to be about 8.7 million tons and 2.4 million tons of the disseminated ore reserve.

• El Shimi et al., (2007) stated that, the disseminated ore bands are extending for about 4.5 km along their strike with thicknesses ranges from 2 to 11 m and an average of 5.3 m while the massive ore bands extending for about 2.4 km with thicknesses ranges from 4 to 11 m and an average of 7.5 m, the area revealed geologic ore reserves of about 15.4 million tons distributed as 7.9 million tons of massive ore and 7.5 million tons of disseminated ore

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• Surveying, the topographic contour map (Scale 1:5000) was constructed by using Total station for the area under study .

• About 875 points were recorded and used for constructing the topographic contour map with contour interval 5 m

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Fig ( ) Location m ap of pits at Gabal Wadhait area

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Contour Line

W. W adhait

W . Kamoyib

Trench

Location map of trenches at G. Wadhait (south G. Korab Kansi)

►Field activity

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• Eight trenches were excavated on occurrences of titanomagnetite ore and perpendicular to the strike direction.

• They were of total lengths of about 350m.• A total of 39 channel samples were collected from the trenches

►Geology of Titanomagnetite ore • According to the percentage of opaque crystals, the ore-

bearing rocks classified into massive and disseminated ores.

• Massive ore, is grayish black or black with metallic luster and opaque minerals represent more than 80% of the whole rock.

• The disseminated ore is brownish grey to greenish black and its opaque minerals range from 20-60% of the whole rock.

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LL

L L L L L L

L L L L L

L L L L L

L L L L LLL

L L L L L

L L L L L

LL

L L L LL L L L

L L L L LL L L L

L L L LL L L

LL

R1 R2

R3

R4

R5

R6

R7D1 D2 D3

D4 D5D6

M1 M2

M3

1m1.7m

5.7m1.6m

2.2m2.6m

4.3m 2.3m2.4m

10.3m 7.8m 1m4.9m 1.5m 2.6m 3m

E

Lat 22 32 52 .4 301488.6Long 35 00 52.1 274348.4

Lat 22 32 523 301437.2Long 35 00 50.3 274345.3

w

Disse m inated Tetanom agnetite O re

M assive Tetanom agnetite O re

Alte red gabbro

Layered gabbro

M afic -u ltram afic rocks

Sam ple No .D 2M 2R 2

LEGEND

L L

L L

Trench No.1

Geological Sketch of Trenches

R1 R2

R3

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R5 R6

R7

D1

D2 D3

M1

1m3m

6m

12m8m

10m2.5m

14m8.5m 2.5m 2.5m 1m

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Lat 22 32 48.4 301111.5Long 35 00 38.9 274225.3

Lat 22 32 44.8 301237.2Long 35 00 43.3 274114.6

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L L L L

L L LL L L L

L L LL L L

L L L

L L L L LL L L L

L L L L LL L

LL L

L L L LL L L L

L LL L L

L L L LL L L

LL

R8

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D4

R10

2m2m 3m

Dissem inated Tetanom agnetite O re

M assive Tetanom agnetite O re

Layered gabbro

M afic -u ltram afic rocks

Sam ple No.D 2M 2R 2

LEGEND

L L

Trench No.2

L L L L

L L L L

L L L LL L L LL L LL L

L L LL L

R1 R2 R3

R4M1 M2

M3

D1

7m.5m

2.35m.5m

3.5m .5m1m 9m

Ew

Lat 22 33 16.0 301228.6Long 35 00 43.0 275074.3

Lat 22 33 15.6 301257.1Long 35 00 44 275062

D issem inated Tetanom agnetite O re

M assive Tetanom agnetite O re

Layered gabb ro

M afic -u ltram afic rocks

Sam ple N o.D 2M 2R 2

LEGEND

L L

Trench No.3

L LL L

L LL L

R1 R2 R3

D1 M1D2

3m 1m1m

2m13m

NESW

Lat 22 33 19 301142.9Long 35 00 40 275166.6

Lat 22 33 20 301171.4Long 35 00 41 275197.3

Trench No.4

L L L L L L LL

L L L L L L L L

L L L L L L L LL L L L L L L

R4 R5

M2

D3

D4

LL

4m 2m2m

1.5m.5m1m

Dissem inated Tetanom agnetite O re

M assive Tetanom agnetite O re

Layered gabbro

M afic -u ltram a fic rocks

Sam ple N o.D 2M 2R 2

LEGEND

L L

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L LL L

L LL L

R1 R2

R3D1

M1

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2m2m

13m3m 2m

8m

Ew

Lat 22 33 48 300942.8Long 35 00 33 276074.0

Lat 22 33 46.7 300977.1Long 35 00 34.2 276018.6

Dissem ina ted Tetanom agnetite O re

M assive Tetanom agnetite O re

Layered gabbro

M afic -u ltram a fic rocks

Sam p le N o.D 2M 2R 2

LEGEND

L L

Trench No.5

L LL L

L LL L

R2

R2

M1

D1

2m

22m

2m 2m 10m

Ew

Lat 22 33 53.4 301157.1Long 35 00 40.5 276224.7

Lat 22 33 53.2 301214.2Long 35 00 42.5 276218.6

L L L L L L L L L

L L L L L L L L

L L L L L L L LL L L L L L L

D2

Dissem inated Tetanom agnetite O re

M assive Tetanom agnetite O re

Layered gabbro

M afic -u ltram afic rocks

Sam ple N o.D 2M 2R 2

LEGEND

L L

Trench No.6

R1 R2 R3

D1 D2

3m 2m8m

SWNE

Lat 22 32 13.5 301585.9Long 35 00 55.5 273151.8

Lat 22 32 13 301557.3Long 35 00 54.5 273136.4

L L L LL L L L

L L LLL L L

R4

R5

D issem inated Tetanom agnetite O re

Layered gab bro

Talc Carbonate

S am ple No.D 2M 2R 2

LEGEND

L L

Altram afic

Trench No.7

20m

2.5m

30m1.5mLat 22 32 52 .4 301488.6

Long 35 00 40 277181.4

Lat 22 34 26.5 301157.0Long 35 00 40 277242.9

NNE4m

SSWDissem inated Tetanom agnetite O re

U ltram a fic rocks

Sam ple N o.D 2M 2R 2

LEGEND

Trench No.8

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Geological Sketch of Trenches

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• Detailed geologic investigation revealed that, the disseminated titanomagnetite ore bands extend for about 4.5 km along strike with thickness range from 2 to 11m (average of 5.3 m)

• while the massive titanomagnetite ore bands extending for about 2.35 km with thickness range from 4 to 11 m ( average of 7.5 m).

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• The two types of the ore (massive and disseminated) occur as layers concordant with layered mafic – ultramafic assemblage. These layers are of very steep exposures, that dip mostly to the east (80 – ْ 90 ْ ). The ore consist of medium to coarse grained, anhedral to subhedral crystals of titanomagnetite.

• However massive zones encountered bounded by disseminated zones from both sides of the ore reverse. The ore is generally encountered surrounded by metagabbro and or serpentinized ultramafic rocks of green color.

• The number and thicknesses of the ore layers vary from place to another along their strike . They are totally eight layers and their thicknesses vary from 2 m to about 11 m.

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► Mineralogical study of the titanomagnetite oreOn the basis of the mineralogical studies, the titanomagnetite ore was divided into three categories.1- The Massive Titanomagnetite Ore: composed mainly of 70 - 80% opaque minerals with 30-20% gangue minerals. The opaque minerals are represented by ilmenite, titanomagnetite and magnetite as major opaque minerals associated with minor amount of, hematite, goethite, ulvospinel, and sulphides 2-Disseminated Titanomagnetite Ore: The disseminated titanomagnetite ore bands contain from 20 to 60% opaque minerals3- Barren country rocks: Opaque minerals here are in minor to rare amounts (less than 5%).

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►Ore reserves of bands

• Detailed geologic investigation revealed that, the disseminated titanomagnetite ore bands extend for about 4.5 km along strike with thickness range from 2 to 11m (average of 5.3 m) while the massive titanomagnetite ore bands extending for about 2.35 km with thickness range from 4 to 11 m ( average of 7.5 m).. For each band, lengths and thickness was calculated with an average of about 100 m subsurface extension as detected by geophysical tools. The specific weight was conceder as 4.05 gm/cm for massive ore and 3.26 gm/cm for disseminated ore.

• According to the geological estimation for the host bands of titanomagnetite ore with about 16. Mt as total ore reserves distributed as 9.6 Mt of the disseminated ore and 6.4 Mt of massive ore.

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► Beneficiation of titanomagnetite ore• One technological sample was collected from the massive and

disseminated titanomagnetite, which represent the ore bands in the area under studied.

• The collected sample weigh 1000 kg with size fraction (-2 cm) and was divided by quartering. Then 250 kg of sample weight was crushed to pass the -1 mm sieve.

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shaking table

Spiral

• Concentration by using spiral and shaking table carried out on 250 kg of the ore and yield pure concentrate (weigh 55.5 kg) i.e. 22.2% = 222 kg / ton of technological sample.

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XRF analyses (wt %) of technological sample (-1mm) before concentration process

Major oxides (wt %)

L.O.I P2O5 K2O Na2O CaO MgO MnO Fe2O3 Al2O3 TiO2 SiO2

0.69 <0.01 0.03 0.56 6.43 13.41 0.24 32.76 8.86 9.76 26.92

Mineralogical study in Frequency wt% of (-1mm) technological sample before concentration process.

Minerals constituents (infrequency wt %)

L. Silicate H. Silicate Sphene Hem.&Goeth. Ilmenite Magnetite

33.44 12.77 4.5 0.74 3.02 45.53

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L.O.I P2O5 K2O Na2O CaO MgO MnO Fe2O3 Al2O3 TiO2 SiO2 Major silicate

0.26 0.01 00 0.26 8.45 9.29 0.35 30.75 5.89 19.96 24.79 Concentrate.

2,76 0.01 0.16 1.12 8.6 15.61 0.18 19.67 11.19 4.45 35.2 Tailing

Result of XRF analyses (wt %) for concentrate and tailing of technological sample

Mineralogical study in frequency wt % of the concentrate.

L.Silicate H.Silicate Sphene Hem&Goeth Ilmenite Magnetite Mineralogy

7.12 18.566 20.10 5.67 17.01 31.54 Concentrate

49.32 15.08 9.24 0.97 1.70 23.69 Tailing

• TiO2 content upgrading from 9.76% in initial sample to 19.96% in concentrate

• Ilmenite content upgrading from 3.02 in initial sample to 17.01 in concentrate

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• Dry Magnetic separation process was carried out on pure concentrate of shacking table at different magnetic field intensities ranging from 2000 gausses to more than 15000 gausses to yield the following products:-

Magnetic Separator

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The results of XRF analyses and mineralogical constituents of magnetic separation products

XRF analyses (wt %) of magnetic separation products of technological sample (-1mm) at the area

H.Silicate Ilmenite Magnetite & Titanomagnetite

ProductsMajor oxide

42.92 25.86 6.81 SiO2

4.42 28.69 14.78 TiO2

10.48 5.68 2.12 Al2O3

12.12 19.92 70.00 Fe2O3

0.22 0.45 0.29 MnO

11.38 10.05 4.97 MgO

16.57 8.93 0.15 CaO

0.96 0.24 < 0.01 Na2O

<0.01 < 0.01 <0.01 K2O

<0.01 < 0.01 <0.01 P2O5

0.93 0.20 0.88 L.O.I

Total Heavy Silicate Ilmenite

Magnetite & Titanomagneti

te

Product sMinerals

concentrate

22.21% 1.33% 3.57% 17.31% Wt %

17.31 - 0.30 100% Magnetite

1.62 7.05 42.69 - Ilmenite

0.36 2.92 9.14 - Hema.-goethite

1.32 34.65 24.02 - Sphene

0.94 37.82 19..57 - Heavy Silicate

0.66 17.56 4.28 - Light Silicate

Mineralogical constituents of magnetic separation products in frequency wt % of technological sample (-1mm) at the area

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◘ Magnetite & Titanomagnetite :It was separated at low magnetic field intensity of 2000 gausses and represent about 17.31% of the initial sample weight with purity 100 %. Chemically the product displays 70 % Fe2O3, 14.78% TiO2 and 6.81% SiO2.

◘ Ilmenite It was separate at moderately field intensity of 10000 gausses and represents about 3.57 % of the initial sample weight, with purity (24.02 - 42.69 %). Chemically, the product displays 19.92% Fe2O3, 28.69% TiO2 and 25.86% SiO2.

◘ Heavy Silicate It was separated at field intensity of 15000 gausses and represents about 1.33% of the initial sample weight, with purity 37.82%. Chemically, the product contains 12.12% Fe2O3, 4.42% TiO2 and 42.92% SiO2.

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• According to the present work, Gabal Wadhait titanomagnetite ore constitute geological reserves of about 16. million tons,

• when crushed to size fraction (-1.00 mm) and subjected to concentration by spiral separator and shaking table to yield (22.21 % = 3.50million tons.

• When ore reserves is crushing to (-1mm) TiO2 content upgraded from 9.76% in initial ore reserves to 19.96 % in concentrate.

• Ilmenite product result from magnetic separation which represent 3.57% of the initial sample weight with purity 42.69 %

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Three important products were obtained from magnetic separation process are:-

1st product constitute 17.31% of initial sample Magnetite & Titanomagnetite with purity 100%)

2nd product constitutes 3.57% of initial sample, Ilmenite with purity (42.69%).

3rd product contains 1.33% of initial sample, heavy silicate with purity 37.82%).

23Flow sheet of massive and disseminated ore

Technical experiments were carried out on the technological sample to design the Flow sheet

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Heavy Minerals in Stream Sediment around Gabal Wadhait area

• The stream sediments are composed mainly of weathered products derived from Gabal Wadhait mafic - ultramafic intrusion and its associated titanomagnetite ore.

• Fifteen samples were collected from 15 pits to study the heavy minerals content of these sediments.

• One technological sample with weight of about (500kg) was collected from fifteen pits which represent the stream sediments in the area.

• It sieved into three size fraction (+10mm), (-10+1mm) and (-1mm)

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• A total of 15 pits were dug in sediments..

• area = 1.42 km2

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Fig. ( ) Location map of pits at Gabal W adhait area

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W. W adhait

W . Kamoyib

Pit Contour Line

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weight -1mm -10+1mm +10mm Size fraction500kg 190 260 50 kg/ton

100 38 52 10 Wt%

dry size analyses for the stream sediment

Digging of pits at W. Wadhait area

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• Size fraction (+10mm) (-10+1mm) were rejected • Size fraction (-1mm) was subjected to concentration by

using spiral separator and shacking table which finally yielded about 6.32% final concentrate and 93.68 % final tailing

Kg/t Wt % Product24 6.32 Heavy conc.

356 93.68 Tailing380 100 total

Result of concentrate and tailing by using shaking table for size fraction (-1mm)

- Size fraction(-1mm) represent 38% of all stream sediments (380 kg/ton) and subjected to concentration by spiral separation supplemented by shacking table to yield 2.40% (24 kg/ton) concentrate and 35.60% (356 kg/ton) tail

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Chemical analyses (XRF) wt% of technological Sample of stream sediments

Chemical analysis ( Wt % ) Products

L.O.I P2O5 K2O Na2O CaO MgO MnO Fe2O3 Al2O3 TiO2 SiO2

3.38 0.27 0.55 1.52 6.31 8.11 0.17 11.31 14.75 2.89 50.43 (-1mm)

0.57 0.86 0.11 0.49 3.45 7.02 0.37 46.45 3.92 25.16 11.6 Conce.

3.43 0.24 0.37 1.33 4.88 9.07 0.17 14.55 9.11 1.82 54.61 tailing

From concentration process, TiO2% increases from (2.89 to 25.16%) and Fe2O3% increases from 11.31 to 46.45 % respectively but SiO2 % decreases from 50.43 to 11.6%.

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Total L. Fraction Heavy Silic. Zircon Rutile Sphene Hematite Ilmenite Magnetite

product.Wt.%/ ton

100 62.704 18.09 0.004 0.003 6.462 4.892 6.77 1.074 (-1mm)38 23.87 6.87 0.002 0.001 2.46 1.86 2.57 0.41 % initial380 238.4 68.7 0.02 0.01 24.6 18.6 25.7 4.1 Kg/ton100 31.285 5.806 0.134 0.134 0.32 8.41 46.62 7.28 Conce.%2.4 0.75 0.14 0.003 0.003 0.01 0.20 1.12 0.17 % initial24 7.5 1.4 0.03 0.03 0.1 2.0 11.2 1.7 Kg/ton100 66.66 15.64 0.003 0.003 0.375 16.702 0.372 0.248 Tailing35.6 23.73 5.57 0.001 0.001 0.14 5.95 0.13 0.09 % initial356 237.3 55.7 0.01 0.01 1.4 59.5 1.3 0.9 Kg/ton

Mineralogical study in frequency wt % for technological sample of stream sediment

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The product of spiral separation and shacking table concentration of the initial (-1mm) fraction (24 kg/t) was subjected to dry magnetic separation at different intensities to yield the following concentrates:

• Magnetite and titanomagnetite concentrate (0.29% = 2.9 kg/ton) with purity 87.73% at 2000 Guess magnetic field intensity

• Ilmenite concentrate (1.98 % = 19.8 kg/ ton) with purity 70.05 % at 10000 Guess magnetic field intensity

• Heavy Silicates concentrate (0.13 % = 1.3 kg/ton) with purity 16.17 % at 15000 Guess magnetic field intensity.

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H.Silicat Ilmenite Magnetite Product smajor oxide

22.63 10.61 4.76 SiO2

15.35 28.42 15.75 TiO2

5.40 2.82 2.22 Al2O3

34.45 44.91 69.21 Fe2O3

0.32 0.42 0.22 MnO

12.74 7.76 5.66 MgO

5.91 3.64 1.12 CaO

0.79 0.48 0.31 Na2O

0.21 0.11 0.05 K2O

1.25 0.31 0.14 P2O5

0.97 0.52 0.56 L.O.I

0.13 1.98 0.29 Wt%

XRF analyses (wt %) of magnetic separation products of technological sample for fraction (-1mm) of stream sediments

Total H.Silicat Ilmenite Magnetite Products

0.23 - 1.26 71.8 Magnetite

1.47 29.82 70.05 15.95 Ilmenite

0.08 3.07 3.00 4.55 Hema-

0.13 7.56 5.85 0.45 Sphene

0.25 16.33 11.54 1.15H.Silicate

0.24 43.22 8.30 6.12L.Silicate

2.40 0.13 1.98 0.29 Wt%

Mineralogical constituents of magnetic separation products in frequency wt% of technological sample .

32 Flow sheet of stream sediment

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• Alluvial sediments (-10mm fraction) derived from Gabal Wadit mafic –ultramfic intrusion, of the area represent about 1.42 km2, (W. Wadhait = 0.9 km2 and W. Kamoyib = 0.52 km2).

• The concentration process for size fraction (-1mm) by using spiral separator and shaking table yield 2.40 % heavy minerals containing, 0.23% magnetite 1.47 % Ilmenite, 0.08 % hematite & goethite, 0.13 sphene, 0.25 heavy silicates and 0.24 % light silicates.

From the stream sediment study we can concluded the following

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Thank You