1. J Electrounal Chem.. 199 (1986) 207-210
Elsewer Sequoia S.A.. Lausanne - Printed m The Netherlands
207
Short communication
ELECTRODEPOSITION OF TITANIUM AND ITS DIOXIDE FROM
ILMENITE
L.H. MADKOUR *
Cherntsty Department, Faculiy of Sctence, Tantu lJmaerst&, Tunta (Egvpt)
A.S. FOUDA
Chemtstn Department, Faculty of Sctence, Mansouro Unwerstty, Munsour~~ (Egvpt)
(Recewed 15th April 1985: in revised form 13th September 1985)
INTRODUCTION
The aim of the present work was to develop a simple and rapid electrolytic
extraction process of titanium [l-3] and its dioxide from the ilmenite ore of the
Eastern Desert. The ore mother liquor used for the electrolysis process is either
produced by direct leaching with 98% H,SO, (S/L = 1 : 15), 35% HCl (S/L = 1: 20)
and alkaline digestion with caustic soda in a ball-mill autoclave at 175°C under a
pressure of 9.5 kg cmP2, or it is prepared through the fusion method using NaOH or
Na,S,O, separately as fluxes at 600-700°C.
EXPERIMENTAL
Ti and TiO, were prepared by electrodeposition on platinum sheets as described
previously [3-61. All the chemicals used were of BDH Analar grade and were used
without further purification; 0.1 M ore leach chloride and sulphate were prepared
from doubly distilled water and their concentrations were determined as given by
Vogel [7].
RESULTS AND DISCUSSION
Baths suitable for the electrodeposition of Ti and TiO, are indicated in Table 1.
The production of titanate and its dissolution are assumed. The effects of current
density, complexing agents. ammonium salt, temperature and current efficiency were
studied. Also, we confirmed the presence of positively and negatively charged
complex species by carrying out experiments using the ion-exchange resin technique
l To whom correspondence should be addressed.
0022-0728/86/$03.50 ‘a 1986 Elsewer Sequoia S.A

2. TABLE1
Suitablebathsfortheelectrolyttcextractionoftttaniumanditsdioxrdefromrlmeniteore
BathComposttionofelectrolytesolution
(in500cm3oreliquor)
PHCurrentProductComplexspectesCurrentRecovery
density/efftctency/W
mAcme2/%
Sulphate
Chloride
Ammonia
Borate
Acetate
Tartarate
Bromide
Fluoride
Oxalate
Urea
Sodium
hydroxide
Oreleachsulphate(0.1M)and20cm3
1MH,SO.,
Oreleachchloride(0.1M)and10cm3
perchloricacid
Oreleachchlonde(0.1M),60g
NH,CIandNH,OH(1:1)
Oreleachchlonde(0.1M).60gNH,CI,
3gboraxandNH,OH(1:1)
Oreleachchloride(0.1M),30gNH,Cl,
50cm3(1M)aceticacidandNH,OH(1:1)
Oreleachchloride(0.1M),40gNH,CI,
50cm3(1M)tartancacidandNH,OH(1:1)
Oreleachchlorideand20cm32MHBr
Oreleachchloride(0.2M).50g
NH,CI,NaFandNH,OH(1:1)
Oreleachchloride(0.1M).60gNH,Cl,
50cm3(1M)oxalicacidandNH,OH(1:1)
Oreleachchloride(0.1M)and5gurea
Oreleachchlonde(0.1M),60g
NaOHand15cm3glycerol
[Ti(OH),HSO,]‘+
[Tt(OH)Cl,+TI]‘+
FXNH3),13+
[Ti(B407)12’
4.0250T199.396.2
3.8240TI99.495.6
9.0200Ti98.797.1
9.0400
7.5230
Tl
TI
99.694.3
99.896.2
5.0250TI[TK&$H,)I’+99.693.4
4.0300Ti[Tt(OH)Br2+Ti]j+99.494.7
8.020099.295.2
8.0600
8.0300
TiO2[TC,)12-
Ti[Ti(C,Q,)12’
TilTWWH,),),13+
99.596.3
98.694.5
10.0300TI[Ti(OH),]”99.493.8

3. 209
[8,9]. The structures of titanium complexes of the type [Ti(NH,),13+ were proved
[lo]. Also, the tartarate 1111,oxalate 1121,bromide, chloride 1131,perchlorate 1141,
sulphate [14], urea [14] and fluoride [15] [Ti(F,)12- complexes of titanium were
identified and proved conductometrically. The formation of Ti and TiO, is dis-
cussed. The results of chemical and spectrophotometric analyses indicate that the
purity of titanium is 99.1%. Also the electron micrograms confirmed by the X-ray
standard tables (ASTM) for TiO, coincide well with those given by chemical
analysis.
The reaction of ilmenite ore with NaOH and its dissolution in H,SO, and WC1
can be represented as follows:
FeTiO, + 2 NaOH + Na zTiO, + Fe0 +H,O
(1) NaZTiO, C 3 H,S04 -+Ti(SO,),+Na,SO,+3 H,O
Ti(SO,), + H,O + TiOSO, + H *SO,
(2) Na,TiO, + 4 HCI -+Ti(OCl)z+2 NaCl +2 Hz0
Ti
The following equation represents the mechanism of formation of the element
from the different baths used 1161:
Ti(L)“++ ne”-+Ti+L
where L is the ligand of the complex species and n is the number of positive charges
on the species. Adsorption of hydrogen ions and complex species on the surface of
Ti protects it from oxidation.
During the deposition of TiO,, the complex species [TiF612- migrated towards the
anode, where it loses its negative charge and dissociates yielding Ti4’ ions. These
ions are oxidized by the OH. radicals at the anode to form TiOz [17].
[TiF612- +Ti4++6 F-
Ti4++ 2 H,O~TiO~+4 H” i
Effect of current density
At low current density (200 mA cme2}, only a thin layer of Ti was deposited and
an oxide with low oxygen content was obtained in the case of TiO, deposition. At
higher current densities (> 400 mA cm-‘), a non-adherent and randomly oriented
deposit [18] of Ti and an oxide with higher oxygen content were obtained. Suitable
current densities for cathodic and anodic deposition are shown in Table 1.

4. Effect of complexmg agent/metal ion ratto
Smooth deposition of bright grey-silver Ti was obtained at low concentration
( = 0.1 M) of complexing agent. Also, the adsorption of complexing agents at the
cathode prevents the oxidation of Ti.
Effect of ammonium salt
Ammonium salt acts as a buffering medium for the bath; it assists the stability of
the Ti complexes. prevents the precipitation of Ti hydroxide as the pH is raised. and
increases the conductance of the solution.
Effect of temperature
Increasing the temperature from 25 to 50°C favours the deposition of Ti and TiO,
owing to the acceleration of both the ionic migration of the complex species and the
oxidation of Ti” at the anode.
Current efficiency
In the ammonia and urea baths the current yield is nearly 99%. The platinum
plate and the dilute solution of Ti are responsible [19] for the current yield being
slightly lower than 100%.
ACKNOWLEDGEMENT
The author would like to thank the Egyptian Geological Survey and Mining
Authority. A.R.E.. for kindly supplying a sample of the title ore.
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