Research Journal of Recent Sciences ________________________________________________ ISSN 2277 - 2502
Vol. 1(ISC-2011), 434-443 (2012)
Res.J.Recent.Sci.

Review Paper

Recovery of Nickel from Spent Ni/Al2O3 Catalysts using Acid Leaching,
Chelation and Ultrasonication
Oza R.* and Patel S.
Chemical Engineering Department, Institute Of Technology, Nirma University, Ahmedabad–382 481, INDIA

Available online at: www.isca.in
(Received 7th November 2011, revised 13th January 2012, accepted 30th March 2012)

Abstract
Supported nickel catalysts, containing 2.5% to 20% of nickel metal, are widely used in chemical industry for hydrogenation,
hydrotreating, and steam-reforming reaction. These catalysts have specific life and are subsequently discarded due to its
deactivation owing to coke deposition on its surface. Disposal of spent catalyst is a problem as it falls under the category of
hazardous industrial waste and also it requires compliance with stringent environmental regulations. Also the cost and demand
of nickel has been rising significantly. In this context recovery of nickel can serve both of the important issues. This review cum
research work focuses on the recovery of nickel from spent nitrogenous catalyst using conventional acid leaching & chelation
route and a novel technique Ultrasonication developed & implemented successfully by the authors. Using ultrasonication
technique significantly faster recovery of nickel salt (50 minutes) was accomplished compared to chelation route (7-8 h) and
acid leaching (5-6 h). The %recovery and purity is significantly high for ultrasonication route compared to conventional acid
leaching and chelation technique. The recovered nickel salts can be recycled for the preparation of fresh catalysts and promises
to be a good industrial process for handling 1-2 t per batch of spent nickel catalyst.
Keywords: Spent catalyst, ultrasonication, chelation, leaching, nickel recovery.

Introduction
Catalysis is the key to chemical transformations. Most
industrial synthesis and processes require catalysis. Large
quantities of catalysts are used in the fertilizer industry (i.e.,
ammonia plants), in petroleum reﬁneries, in the chemicals
sector, in various conversion processes, and in automotive
catalytic converters for pollution control. The development
of chemical products in advanced, industrialized societies is
technically, economically and ecologically possible by
means of specific catalysts. 95% of all products (volume) are
synthesized by means of catalysis while 20% of the world
economy depends directly or indirectly on catalysis. The
importance of catalysis to chemical processes is enormous.
An estimated 70% of all the chemical products (processes)
are based on catalytic technologies, encompassing four major
market sectors: fuel refining, polymerization, chemical
production and environmental remediation. It has been
estimated that more than 80% of the added value in chemical
industry is based on catalysis. Approximately 80% of all
catalytic processes require heterogeneous catalysts.
Heterogeneous supported nickel catalysts are commonly used
for various industrial processes such as hydrogenation
reactions, hydro-treating, steam reforming, and methanation14
. Nickel is cheap and sufficiently active, and allows suitable
catalysts to be economically produced. These catalysts
deactivate over time, and when the activity of a catalyst
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declines below an acceptable level, the catalyst has to be
regenerated and reused. However, when online/in situ
regeneration is not possible, or even after a few cycles of
regeneration and reuse, the catalyst activity might decrease to
very low levels, so that further regeneration might not be
economically feasible. In such cases, spent catalysts tend to
be discarded as solid wastes4. Ni catalysts deactivate over a
lifespan of about 5-7 years because of the harsh conditions in
the primary and secondary reformer5. Therefore fresh
catalyst is required to be loaded in the reactors after certain
time period. The replacement costs for an expensive metal
catalyst is a major expenditure item in chemical and allied
industries. Also spent catalysts contribute a significant
amount of the solid wastes generated in the chemical and
allied industries7. The dumping of catalysts in landfills is
unacceptable, as the metals present in the catalysts can be
leached into the groundwater, resulting in an environmental
catastrophe5. In addition to the formation of leachate, the
spent catalysts, when in contact with water, can liberate toxic
gases as well5. As a result of stringent environmental
regulations on spent catalyst handling and disposal, research
on the development of processes for the recycling and reuse
of waste spent catalysts has received considerable attention5.
The metal recovery from nickel catalyst is also extremely
important from an economic point of view, as these metals
command a significant price in the market and increasing
environmental concerns and legislation regarding the

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disposal of hazardous spent catalysts, companies and
countries are being forced to process their own waste
products and residues.

Deactivation of Nickel Catalysts
Catalyst deactivation, the loss over time of catalytic activity
and/or selectivity, is a problem of great and continuing
concern in the practice of industrial catalytic processes. It is a
result of a number of unwanted chemical and physical
changes. The supported catalysts use the alumina, zeolites,
carbon, silica, zirconia, clay materials as support with
catalytic metals such as nickel, platinum, palladium,
molybdenum, cobalt, copper, iron etc. While in use these
catalysts become spent or poisoned due to loss of surface
area, sintering and/or to the fixation thereon of various
compounds like carbon, sulfur etc2. While catalyst
deactivation is inevitable for most processes, some of its
immediate, drastic consequences may be avoided, postponed,
or even reversed. The mechanisms of solid catalyst
deactivation can be grouped into six intrinsic mechanisms of
catalyst decay: (1) poisoning, (2) fouling, (3) thermal
degradation, (4) vapor compound formation and/or leaching
accompanied by transport from the catalyst surface or
particle, (5) vapor–solid and/or solid–solid reactions, and (6)
attrition/crushing. As mechanisms 1, 4, and 5 are chemical in
nature while 2 and 5 are mechanical, the causes of
deactivation are basically threefold: chemical, mechanical,
and thermal.
It is known that conventional nickel-based catalysts suffer
from severe catalyst deactivation in the steam reforming
reactions due to the carbon deposition and nickel sintering.
Deposition of the coke is the most common processed but
deposition of the rust and scale from elsewhere in the system
is also possible. The presence of nickel in the deposit leads to
major increases in the rate of gasification. Gasification of
coke by reaction with oxygen is often the preferred route,
since the reaction is fast and efficient. However, the
exothermic reaction can easily result in overheating and in
thermal reorganization.
Poisoning involves strong chemical interaction of a
component of the feed or products with active sites on the
catalyst surface1. The most common cause of poisoning
involves strong chemisorptions of gas phase species on the
active sites. If the chemisorptions are weak, desorption and
reactivation may occur. However, the catalyst deactivates if
the chemisorptions are strong. The effectiveness of a poison
depends on the equilibrium constant for the poisoning
reaction and on the catalyst activity of the product formed.
Sulfur is a good case in point. Poisoning can generally be
classified as either reversible (temporary) or irreversible
(permanent). After temporary poisoning, catalytic activity
can be largely recovered by removing the poison source or
by adequately cleaning the catalyst surface by air oxidation
and/or steaming. The irreversible effect of permanent poisons

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is due to their being so strongly adsorbed that they cannot be
adequately removed. Loss in catalyst activity often includes
reduced cycle length, increased pressure drop in the reactor
and increased carbon deposition.
Catalysts are also deactivated by sintering which causes loss
of active surface area and therefore lowers catalytic activity.
In general, catalysts deactivated by thermal degradation,
phase separation or phase transformations, cannot be
reactivated easily and therefore, replacement is necessary1.
Sintering is the process of agglomeration of the crystallites of
the active phase, which leads to loss of active surface and,
consequently, a decrease in activity. The sintering process is
influenced by many parameters, among which the
temperature and the atmosphere over the catalysts are the
most important ones. Sintering rates increase strongly with
temperature and are particularly large in the presence of
water. The formation of nickel aluminate fromthe reaction
between nickel and alumina is a good case in point, with the
catalytic activity of Ni-aluminate being much lower than that
of the metal. Alloy formation or phase separation can also
occur which could lower overall catalytic activity.

Spent Nickel Catalyst Handling Options
The steam-reforming process for producing hydrogen for
ammonia production requires that the catalysts be replaced
after every 6 years in service, although the life of catalysts
has increased to 9 years. The quantity of spent catalysts
discharged from different processing units depends largely
on the amount of fresh catalysts used, their life, and the
deposits formed during use in the reactors. Environmental
laws concerning spent catalyst disposal have become
increasingly more severe in recent years. Disposal of spent
catalyst is a problem as it falls under the category of
hazardous industrial waste. Spent catalysts have been
classified as hazardous wastes by the United States
Environment Protection Agency (USEPA). The recovery of
metals from these catalysts is an important economic aspect
as most of these catalysts are supported, usually on
alumina/silica with varying percent of metal; metal
concentration could vary from 2.5 to 20%1. Recovery of
metals from spent catalysts depends on several factors: the
nature of the sample (chemical composition) and the treated
feedstock, the price of metals, the environmental directories,
the distance between the refinery and the recycling industry
and the operational costs. This has presented an opportunity
for a new business to rejuvenate, recycle and convert the
spent catalyst to an environmentally acceptable safe material
for recycle. Several alternative methods such as disposal in
landfills, reclamation of metals, regeneration/rejuvenation
and reuse, and utilization as raw materials to produce other
useful products are available to the refiners to deal with the
spent catalyst problem. The choice between these options
depends on technical
feasibility and economic
considerations. Among all these methods metal reclamation

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has attained maximum attention as the recovered metals such
as Mo, V, Ni and Co could be used in steel manufacture and
the alumina could be used for the manufacture of
refractories, ceramics and abrasives. The metal reclamation
option can provide a complete solution to the environmental
problem of spent hydroprocessing catalysts in a profitable
way. This option, however, does not provide a complete
solution for all types of catalysts. In some cases only partial
recovery is possible which leaves the remaining portion to be
treated or disposed by other methods.

diffusion of reactants from the interface to the bulk of the
second phase takes place. Further, chemical reactions
between the reactants in phase one and those in phase two
occur. Finally, the products diffuse within the second phase
and/or out of phase two into the bulk of phase one.
There has been report on the recovery of nickel from a spent
catalyst used in an ammonia plant by leaching in sulphuric
acid7. The main reactions taking place is as follow:

NiO + H2SO4  NiSO4 + H2O

Treatment of Spent Nickel Catalyst
Recovery of metals and other components from the spent
catalysts is possible, and the technology for metals
reclamation is well established. For catalysts containing Mo,
Ni, Co, V and Al2O3, process economics for recovery of the
metals are influenced by metals prices, metals content,
transportation costs and purity of the recovered metals .
Commonly, two methods are suggested for recovery of
nickel from ores and raw materials of technological origin:
pyrometallurgical technique, whose main product is
ferronickel
obtained
at
high temperatures,
and
hydrometallurgical, based on leaching-out of nickel from raw
materials with various acids and solutions of ammonia and
ammonium salts2,6. Hydrometallurgy processes have been
widely applied to metal recovery from industrial wastes, due
to their flexible, environmentally–friendly, and energysaving characteristics.

Leaching
Leaching require the maximum solubilization of the sample
in an appropriate medium for the other central step, the
separation of solubilized elements. For this purpose, it is
necessary to pre-treat the sample in order to remove coke and
other volatile species present. This step “cleans” the catalyst
surface, thus reducing losses of recoverable metals by
physical blocking. Care must be taken to avoid catalyst
ignition during pre-treatment, thus forming refractory oxides
that are difficult to solubilize in the leaching medium.

(1)

The side reaction taking placing is as follows:

 -Al2 O3  3H2SO4  Al2 SO4 3 + 3H2O

(2)

The nickel was recovered as NiSO4 with 99% yield when the
catalyst, having a particle size of 0.09 mm, was dissolved in
an 80% sulfuric acid solution for 50 min in at 70ºC. It was
also shown that the high recovery of 99% nickel as nickel
sulphate was achieved. Nickel was to be directly recovered
as a sulfate salt by direct crystallization method. The
recovery was done using sulphuric acid leaching process for
the recovery of nickel as a sulphate from a spent catalyst in
the steam reforming industry8,9,10-12. A study was carried out
for the recovery of nickel from a spent catalyst used for the
steam conversion of methane6. They found that the leaching
of nickel is limited by the bulk of the leaching solution.
By leaching the spent catalyst with hydrochloric acid, a
reseacher reported for the recovery of nickel as nickel oxide
from a spent catalyst containing 17.7% Ni13. They found that
the maximum of nickel extraction (73%) could be achieved
by carrying out the leaching process with 28.8% HCl at
80ºC. The rate of the side reaction is very weak because
alpha alumina is completely inert towards acids because it
was previously produced by calcination of Al(OH) 3 above
1000ºC which gives it great stability towards acids. Alpha
alumina is used in the refractory industry for making
crucibles, bricks and spark plugs9. The main reaction for
nickel extraction from both the catalysts is as follows:

Acid Leaching
The reaction of nickel oxide with acid is a heterogeneous
reaction. In a heterogeneous reaction system the overall rate
expression becomes complicated because of the interaction
between physical and chemical processes. The reactants in
one phase have to be converted to another phase in which the
reaction takes place. The mechanism of the uncatalyzed
heterogeneous reaction may take place as follows. Initially,
the reactants diffuse from the bulk of the first phase to the
interface between the phases. If an additional layer of solid
product and inert material is present at the interface the
reactants would have to overcome the resistance of this layer
before reaching the surface of the second phase. Then,

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NiO + 2HCl  NiCl2 + H2O

(3)

whereas the side reaction is:

 -Al2 O3  6HCl  2AlCl3 + 3H2O

(4)

The rate of the side reaction is very slow since α-Al2O3 is
inert towards acids2. The entire flow sheet for the recovery is
as shown in Figure-1. A group of researcher examined that
the leaching efficiency of 95% was obtained from the spent
nickel catalysts using nitric acid solution having size
between 1-2 mm was achieved at optimized conditions: 40%

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acid concentration (v/v), temperature 90ºC, solid:liquid ratio
of 1:10 g/ml and leaching time 5 h3. The series of reactions
taking place are as follows.

dissolution and subsequent precipitation have been used for
the treatment of the spent nickel catalyst14. The recovery of
nickel from the leachates was performed at room temperature
by precipitating with sulphide generated by Desulfovibrio
cells. Indirect precipitation using sulphide generated in
NiO-Al2 O3  2H2 O  Ni  OH 2 -Al2O3 .H2O
(5)
Desulfovibrio sp. cultures allowed the recovery of nickel as


the very insoluble nickel sulphide. A Ni recovery of 62.8%
HNO3  H2 O  H3O  NO3
(6)
from spent refinery catalyst was obtained using Aspergillus
niger15.


Ni  OH 2 -Al2 O3 .H2 O  NO3  H3O  Ni  NO3 2 .6H2O  Al2O3 .H2O  H2O
(7)
Alkali Leaching
A group of researchers studied leaching of spent catalyst
with caustic soda solution and treated residue with sulfuric
It was found that the recovery of nickel is increased by
acid solution for recovery of nickel16. A study on the
dissolution with 60–70% nitric acid concentration at 120ºC
recovery of nickel from Al2O3 support using (NH4)2CO3 for
for 2–3 h11.
600 mm particle size at 80 ºC was done and optimum
leaching conditions were achieved17. Nickel was precipitated
Bioleaching
by adjusting the acidity at pH > 8.0 using 1.0 mol of sodium
Bioleaching is a novel approach to recover metals from
carbonate solution. However, the leaching methods described
various solids. Bioleaching processes are based on the ability
in the literature have certain limitations. An attempt was
of microorganisms (bacteria or fungi) to transform solid
made to recover nickel by extraction of the spent catalyst
compounds, via the production of organic or inorganic acids
with an aqueous solution of 15–23% ammonia at 60–90 ºC
which results in soluble and extractable elements that can be
and at pH 7.5–9 and nickel was recovered as nickel nitrate
recovered. Bioleaching can be considered as a ‘clean
but the ammonia used is a toxic gas18. A study on leaching of
technology’ and this is associated with lower cost and energy
spent nickel catalyst first with 50% NaOH in autoclave at
requirements in comparison to non-biological processes. It
150-175 °C to dissolve Al as Na-aluminate was made. The
also offers good prospects for recovering valuable metals and
residue treated with HNO3 (1:1) at 60 °C to dissolve nickel in
at the same time, generates much less environmental
the solution19.
pollution. A research was carried out taking into
consideration integrated biological processes involving the
SPENT
CATALYST

CRUSHING

SCREENING

COKE REMOVAL

HNO3
SOLUTION

ACID LEACHING

EVAPORATION

WATER

CRYSTALLIZATION

WATER

Ni(NO3)2.6H2O
Crystals

Figure-1
Flow diagram of the acid leaching based Ni recovery process

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Multistage Leaching
In order to increase recovery of metals, multi stage leaching
has been proposed. The results obtained in single-stage
leaching showed that the percentage recovery of nickel
increased with increasing acid concentration used up to 25%
and then the percentage recovery of nickel decreased. Also,
the percentage recovery of nickel increased as the time of
leaching increased. The optimum time was 3 h with three
stages; each stage for 1 h. Using multi-stages gave 82%
recovery while using two stages with the same acid
concentration for 2 h gave 84% recovery. Increasing the
number of stages leads to the use of lower acid
concentration20.

Chlorination
It is well known that chlorine possesses a high reactivity
towards many compounds at relatively low temperature. This
property drove the metallurgists to use chlorine for the
extraction of valuable elements from their bearing materials.
With this in perspective, during the last two decades the
authors have been focusing their efforts on developing
several chlorination techniques for the treatment of numerous
raw materials and solid industrial wastes A report was made
on recovery of Nickel from spent hydrocracking catalyst
roasted at 390°C with NH4Cl, leaching with water at 80°C
and crystallization as NiCl2 at 85% nickel yield21.

Plasma Sintering
The reduction of nickel oxide to nickel is of great interest,
owing to nickel being an important electronactive material in
electrochemical systems such as batteries, fuel cells and
alkaline electrlizers. Many studies have been concerned the
reduction of oxidized nickel and some recent work dealt with
heating the NiO surface22-23 and nickel-supported catalysts2429
by the different reduced source and sintering technologies.
A.C. plasma has been widely used in a number of fields such
as ceramics and the metallurgy industry because of the
characteristics of high temperature (usually up to 5,000 ºC)
with high densities of ions and electrons 30-31. These diverse
active species with the high energy radiation capability of the
A.C. plasma can help to enhance the chemical reactions
substantially and to make some reactions possible. As for
gasification, it is commonly applied to convert coal32,
biomass33, and waste materials30,34-36 to syngas and useful
chemicals in industries. A study carried out by group of
researchers indicates the utilization of plasma and
gasification technique for the reduction of nickel oxide in the
spent nickel-based catalyst (NiO/SiO2) to nickel. The syngas
(CO + H2), generated from the partial oxidation of organic
tar, was served as the reducing agents37.

Chelation

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Chelating agents are the most effective extractants that can
be introduced in the soil washing fluid to enhance heavy
metal extraction from contaminated soils. The advantages of
chelating agents in soil cleanup include high efficiency of
metal extraction, high thermodynamic stabilities of the metal
complexes formed, good solubilities of the metal complexes,
and low adsorption of the chelating agents on soils1. A group
of scientists have studied the effect of chelating agents that
cause only minor impact on the physical and chemical
properties of the soil matrix compared to acids38.
Ethylenediaminetetraacetic acid (EDTA) is the most widely
used synthetic chelating agent in soil washing. It is an
effective, recoverable and reusable chelating agent that has
great potential for full scale application. Many studies have
reported that EDTA could extract very high percentages of
Pb and Cd from contaminated soils39-43. A nuisance arises
associated with EDTA usage when it has to be destroyed
before discharge. The compound is generally regarded as
non-biodegradable and can be found in sewage effluents, and
accumulates in surface waters and groundwater 44-45. The
unusual property of EDTA is its ability to chelate or complex
metal ions in 1:1 metal-to-EDTA complexes. The fully
deprotonated form (all acidic hydrogens removed) of EDTA
binds to the metal ion. The equilibrium or formation
constants for most metals, especially the transition metals,
are very large; hence the reactions are shifted to the complex.
Many of the reactions are pH dependent, especially the
weaker forming complexes with Ca2+ or Mg2+. EDTA forms
a complex with nickel depending upon the concentration of
EDTA that can be represented as the following reaction:

NiO  Alumina s  EDTA  l



 Ni   EDTA 

2

 l

(8
Alumina s
)

After the chelation, the residue material (alumina) was
separated from the complex solution by filtration. Filtrate is
subjected to de-chelation process in which metal-chelate is
separated by changing the pH of solution depending on the
type of complex. Generally, Ni-EDTA complex is not stable
in acidic solutions. Therefore acid is used to de-chelate the
formed complex during the chelation process. The entire
flowsheet for the recovery is as shown in Figure-2.
 Ni   EDTA 

2
(l )

(9
 HNO3(l )  Ni  NO3 2 .6H2 O(l )  EDTA( s )
)

After complete settling of precipitated EDTA, it is sent for a
filtration process. The EDTA is separated as a spent
chelating agent and nickel is extracted as a nickel nitrate
solution. The recovered EDTA is further purified and reused.
A study has beeen carried out on the recovery of nickel from
a spent catalyst using EDTA-di sodium salt as a chelating
agent after which sulfuric acid was added to obtain
NiSO418,84. The extraction was up to 95% under the

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Res.J.Recent.Sci
following conditions: 0.8M concentration of EDTA, S:L
ratio 1:50 (g:mL), particle size 100 µm, pH 10, chelation
time 10 h, 700 rpm and 100 ºC. Similiarlity another group of
researcher studied the chelation therapy for recovery of
nickel metals. The extraction was up to 95% under the
following conditions: 1M concentration of EDTA, solid to
liquid ratio 1:10 (gm/mL), particle size 1-2 mm, pH 10, 7
hours of chelation time, 400 rpm and 90°C9.

Ultrasonication
During the last two decades, ultrasonic study of liquid
mixtures has gained much importance in assessing the
nature of molecular interactions present in the
mixtures47. In the literature applications of sonochemistry
have been reported in the chemistry and related chemical
and materials technologies48-49. The research has also been
going on the ultrasonication based leaching and reaction
world wide49,50. In our previous publication promising
results about recovery of nickel from spent nickel catalyst
using ultrasonication assisted leaching has been reported 7.
The enhanced recovery was achieved compared to the
conventional acid leaching technique. Ultrasonication offers
great potential in the processing of liquids and slurries, by
improving the mixing and chemical reactions in various
applications and industries. Ultrasonication generates
alternating low-pressure and high-pressure waves in liquids,
leading to the formation and violent collapse of small
vacuum bubbles. Each collapsing bubble can be considered

as a microreactor in which temperatures of several thousand
degrees and pressures higher than one thousand atmospheres
are created instantaneously. This phenomenon is termed
cavitation and causes high speed impinging liquid jets and
strong hydrodynamic shear-forces2. Cavitation causes solute
thermolysis along with the formation of highly reactive
radicals and reagents, such as hydroxyl radicals, hydronium
ions etc, which induce drastic reactive conditions in the
liquid media thereby increasing the rate of reaction
drastically. In addition, if a solid is present in solution, the
sample size of the particles is diminished by solid
disruption, thereby increasing the total solid surface in
contact with the solvent. A report on the nickel recovery of
95% at 40% (v/v) HNO3 concentration, 90 ºC, S:L=1:10
g/mL in 50 minutes from spent nickel catatalyst has been
made compared to reaction time 7 h for the EDTA chelation
route. The entire flow sheet for the recovery is as shown in
Figure-3 Use of acid solutions with pH<1 for leaching out
nickel complicates the process of selective recovery of
nickel from a solid matrix and also leads to formation of byproducts. This can be avoided using ultrasonication assisted
leaching as it is able to remove even the smallest metal
particle from the substrate. The enhanced recovery using
ultrasonication is due to its ability of creating highly
reactive surfaces, increasing reaction rate, efficient energy
usage and increasing mass transport. Thus ultrasonication
technique ensures pure product devoid of any by-product.

Figure-2
Flowsheet for the recovery of metal using EDTA

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Vol. 1(ISC-2011), 434-443 (2012)
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SPENT
CATALYST

CRUSHING

SCREENING

COKE REMOVAL

HNO3
SOLUTION

ULTRASONICATION

EVAPORATION

WATER

CRYSTALLIZATION

WATER

Ni(NO3)2.6H2O
Crystals

Figure-3
Flowsheet for the recovery of metal using ultrasonication based Ni recovery process

Conclusion
Looking at the increasing cost of disposal and transportation
of spent catalysts, high cost of metals, stringent
environmental regulations for the emission and disposal
of hazardous spent catalysts metal recovery is the best
solution for handling spent catalysts. In this context lots
of efforts are being made towards the conventional acid
leaching and new methods like chelation route and
ultrasonication. The recovery cost using conventional
leaching method is less but the %recovery and time
consumption is more when compared to chelation and
ultrasonication based recovery. There is a great potential
in developing the ultrasonication based nickel recovery.
The recovered nickel salts can be recycled back for the
preparation of fresh batches of catalysts or can also be
use for the other applications. Ultrasonication ensures
better control of process parameters like temperature and
pressure when compared to complicated acid leaching
and chelation techniques. This is due to the fact that the
entire process is carried out in one single unit unlike the
other two techniques.

References
1.

Singh B., Treatment of spent catalyst from the
nitrogenous fertilizer industry - A review of
the available methods of regeneration,
recovery and disposal, J. Hazard. Mater.,
167(1-3), 24-37 (2009)

2.

Oza R. Shah N. and Patel S., Removal of
Nickel
from
Spent
Catalysts
using
Ultrasonication Assisted Leaching, J. Chem.
Technol. Biotechnol., 86(10), 1276-1281
(2011)

3.

Oza R. Shah N. and Patel S., Nickel Recovery
from Spent Ni/Al2O3 Catalysts using Nitric
Acid Solution, Asian J. Water, Environ.
Pollut,. 8(3), 29-35 (2011)
Oza R. Shah N. and Patel S., Extraction of
Nickel from Spent Catalyst using EDTA as

4.

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Chelating Agent, Nat. Environ.
Technol., 10(2), 197-200 (2011)
5.

6.

7.

8.

9.

Pollut.

Vuyyuru K. R. Pant K. K. Krishnan V. V. and
Nigam K. D. P., Recovery of Nickel from
Spent Industrial Catalysts Using Chelating
Agents, Ind. Eng. Chem. Res., 49(5), 2014–
2024 (2010)
Kolosnitsyn V. S. Kosternova S. P.
Yapryntseva O. A. Ivashchenko A. A. and
Alekseev S. V., Recovery of nickel with
sulfuric acid solutions from spent catalysts for
steam conversion of methane, Russian J. Appl.
Chem., 79, 539–543 (2006)
Ivascan S. and Roman O., Nickel recovery
from spent catalyst. I Solvation process, Bu1
Inst Politeh Iasi Sect 22, 47–51 (1975)
Sinka G. Vigvari M. Koracsi G. Legal T.
Gyalasi I. and Gabor G., Recovery of Ni from
spent catalyst, Hung Teljes HU, 46, 556
(1988)
Al-Mansi N. M. and Abdel Monem N. M.,
Recovery of nickel oxide from spent catalyst,
Waste Manage., 22, 85–90 (2002)

10. Pamela A. Mukharjee T. K. and Sundaresan
A. M., Reduction roasting – sulphuric acid
leaching of nickel from a spent catalyst, Metal
Mineral. Process., 3, 81–92 (1991)
11. Sahu K. K. Agarwal A. and Pandey B. D.,
Nickel recovery from spent nickel catalyst, J.
Waste Manage. Res., 23, 148–154 (2005)
12. Matkovic V. Markovic B. Sokic M. and
Vuckovic N., Recycling of spent nickel based
catalysts, Acta Metallurgica Slovaca., 12,
284–288 (2006)
13. Chaudhary A. J. Donaldson J. D. Boddington
S. C. and Grimes S.G., Heavy metals in
environment: part II. A hydrochloric acid

International Science Congress Association

leaching process for the recovery of nickel
value from a spent catalyst, Hydrometall.,
34,137–150 (1993)
14. Bosio V. and Vierra M. and Donati E.,
Integrated bacterial process for the treatment
of a spent nickel catalyst, J. Hazard. Mater.,
154(1-3), 804-810 (2008)
15. Santhiya D. and Ting Y., Bioleaching of spent
refinery processing catalyst using Aspergillus
niger with high-yield oxalic acid, J.
Biotechnol., 116(2), 171-184 (2005)
16. Shinohara Y. and Mitsuhasli M., Leaching of
valuable metal in waste desulfurization
catalyst, Japan kokai, 76 82–86 (1976)
17. Floarea O. Mihai M. Morarus M. Kohn D. and
Sora M., Filtration: physical models and
operating conditions, Rev Chim (Bucharest),
42 553 (1991)
18. Vicol M. Heves A. and Potoroaca M.,
Recovery of nickel from spent catalysts,
CombinatuldeIngrasaminteChimicePiatraNeamt, 112, 832 (1986)
19. Manoliu C. Olara I. Zugravescu P. Serdaru M.
and Popescu E., Metal recovery from spent
Ni/AlO3 catalyst, Rom. Ro., 87, 980 (1985)
20. Ghanem R. Farag H. Eltaweel Y. and Ossman
E., Recovery of nickel from spent catalyst by
single and multi-stage leaching process, Int. J.
Environ. Waste Manag., 2(6), 540–548 (2008)
21. Molnar L. Sinka G. Szentgyorgyi G. and
Lukacs P., Ni recovery from spent
hydrocracking catalyst, Hung Teljes HU, 46,
565 (1988).
22. Kitakatsu N. Maurice V. Hinnen C. and
Marcus P., Surface hydroxylation and local
structure of NiO thin films formed on Ni(111),
Surf. Sci., 407(1-3), 36-58 (1998)

441

Research Journal of Recent Sciences ____________________________________________________________ ISSN 2277 - 2502
Vol. 1(ISC-2011), 434-443 (2012)
Res.J.Recent.Sci

23. Kitakatsu N. Maurice V. and Marcus P., Local
decomposition of NiO ultra-thin films formed
on Ni(111), Surf. Sci., 411(1-2), 215 (1998)
24. Jesus J. C. Carrazza J. Pereira P. and Zaera F.,
Hydroxylation of NiO films: the effect of
water and ion bombardment during the
oxidation of nickel foils with O2 under
vacuum, Surf. Sci., 397(1-3), 34-47(1998)
25. Christel L. Pierre A. and Abel D. A-M. P.,
Temperature programmed reduction studies of
nickel manganite spinels, Thermochim Acta.,
306(1-2), 51-59 (1997)
26. Richardson J. T. Scates R. and Twigg M. V.,
X-ray diffraction study of nickel oxide
reduction by hydrogen, Appl. Catal. A:Gen.,
246(1), 137-150 (2003)
27. Sharma S. K. Vastola F. J. Walker P. L. Jr.,
Reduction of nickel oxide by carbon: I.
Interaction between nickel oxide and pyrolytic
graphite, Carbon., 34(11), 1407-1412 (1996)
28. Liu S. Xu L. Xie S. Wang Q. and Xiong G.,
Partial oxidation of propane to syngas over
nickel supported catalysts modified by alkali
metal oxides and rare-earth metal oxides,
Appl. Catal. A:Gen., 211(2), 145-152 (2001)
29. Sehested J. Carlsson A. Janssens T. V. W.
Hansen P. L. and Datye A. K., Sintering of
Nickel Steam-Reforming Catalysts on
MgAl2O4 Spinel Supports, J. Catal., 197(1),
200-209 (2001)
30. Pfender E., Thermal Plasma Technology:
Where Do We Stand and Where Are We
Going?, Plasma Chem. Plasma Process,
19(1), 1-31 (1999)
31. Tanahashi N. Takeuchi A. and Tanaka K.,
Metal Recovery From the Waste Magnesia-

International Science Congress Association

Chromia Bricks With Arc Plasmas, J. Eng.
Res. Technol., 123(1), 76-80 (2001)
32. Chatterjee P. K, Datta A. B and Kundu K. M.,
Fluidized bed gasification of coal, Can. J.
Chem. Eng., 73(2), 204-210 (1995)
33. Herguido J. Corella J. and Gonzalez-Saiz J.,
Steam gasification of lignocellulosic residues
in a fluidized bed at a small pilot scale. Effect
of the type of feedstock, Ind. Eng. Chem. Res.,
31(5), 1274-1282 (1992)
34. Judd M. R., In: 2nd International Coal & Gas
Conversion Conference, Pretoria, 23 (1987)
35. Liu S. Xiong G. Yang W. Xu L. Xiong G. and
Li C., Partial oxidation of ethane to syngas
over nickel‐based catalysts modified by alkali
metal oxide and rare earth metal oxide, Catal.
Lett. 63(3-4), 167-171 (1999)
36. Huff M. Torniainen P. M. and Schmidt L.D.,
Partial oxidation of alkanes over noble metal
coated monoliths, Catal. Today, 21(1), 113128 (1994)
37. Wong F. F. Lin C. M. Chang C. P. Huang J.
R. Yeh M. Y. and Huang J. J., Recovery and
Reduction of Spent Nickel Oxide Catalyst via
Plasma Sintering Technique, Plasma Chem.
Plasma Process., 26(6), 585-595 (2006)
38. Fischer K. Bipp H. P. Riemschneider P.
Leidmann P. Bieniek D. and Kettrup A.,
Utilization of biomass residues for the
remediation of metal-polluted soils, Environ.
Sci. Technol., 32(14), 2154–2161 (1998)
39. Steele M.C. and Pichtel J., Ex-situ remediation
of a metal contaminated superfund soil using
selective extractants, J. Environ. Eng., 124(7),
639–645 (1998)
40. Papassiopi N. Tambouris S. and Kontopoulos
A., Removal of heavy metals from calcareous

442

Research Journal of Recent Sciences ____________________________________________________________ ISSN 2277 - 2502
Vol. 1(ISC-2011), 434-443 (2012)
Res.J.Recent.Sci

contaminated soil by edta leaching, Water Air
Soil Pollut., 109(1-4), 1–15 (1999)

Environ. Sci. Technol., 29(11), 2814–2827
(1995)

41. Garrabrants A. C. and Kosson D. S., Use of a
chelating agent to determine the metal
availability for leaching from soils and wastes,
Waste Manage., 20(2-3), 155–165 (2000)

46. Goel S. Nigam K. D. P and Pant K, K,,
Extraction of Nickel from spent catalyst using
fresh and recovered EDTA, J. Hazard. Mater.,
171(1-3), 253-261 (2009)

42. Kim C. and Ong S. K., Recycling of leadcontaminated EDTA wastewater, J. Hazard.
Mater., 69(3), 273–286 (1999)

47. Vadamalar R. Mani D. and Balakrishnan R.,
Ultrasonic Study of Binary Liquid Mixtures of
Methyl
Methacrylate
with
Alcohols,
Res.J.Chem.Sci., 1(9), 79-82 (2011)

43. Wasay S. A. Barrington S. and Tokunaga S.,
Organic acids for the in situ remediation of
soils polluted by heavy metals: soil flushing
columns, Water Air Soil Pollut., 127(1-4),
301–314 (2001)
44. Bergers P. J. M. and de Groot A. C., The
analysis of EDTA in water by HPLC, Water
Res., 28(3), 639–642 (1994).
45. Kari F. G. and Giger W., Modeling the
photochemical
degradation
of
ethylenediaminetetraacetate in the river Glatt,

International Science Congress Association

48. Mason T.J., Advances in Sonochemistry,
Elsevier Science Publishers, New York, 1–6
(1990–2001)
49. Suslick K. S., Ultrasound: its Chemical,
Physical and Biological Effects. VCH, New
York (1988)
50. Crum L. A., Mason T.J., Reisse J. and Suslick
K. S., Sonochemistry and Sonoluminescence,
Kluwer Academic Publishers (1999)

443

