Note: Descriptions are shown in the official language in which they were submitted.
CA 02461624 2004-03-22
1343
PROCESS FQR PRODUCING NICKEL CA~ONYL.
NICKEL POWDER AND USE TI~REOF
S FIELD OF THE INVENTION
This invention relates to processes for producing nickel carbonyl, more
particularly to producing nickel powders of use in producing said nickel
carbonyl by
reaction with carbon monoxide, and to said nickel powders made by said
process.
BACKGROUND TO THE INVENTION
Nickel carbonyl, Ni(CO)4 was first produced by the reaction of metallic nickel
with carbon monoxide by Mond in the early part of the 19'" century. Today, one
of
the major industrial processes for making metallic nickel is,based on the
production of
Ni(CO)4 and subsequent thermal decomposition thereof to Ni and CO. One known
commercial process operates at about 180°C and a CO pressure of about
70 atm. It is
known that the CO pressure may be reduced when the reactant nickel is
catalytically
activated.
Activation of the metal has been observed in the presence of mercury (1, 2),
sulfur in the form of H2S (3, 4), hydrogen (5, 6) or carbon (7). It has been
suggested
that the high initial rate of formation of Ni(CO)4 and the subsequent decline
to a
steady state value is the result of a rapid decrease in the number of
activated reaction
sites which are produced upon heat treatment of the sample (8, 9, 6). A study
of
surface changes during carbonyl synthesis suggests that the maximum rate is
associated with fundamental changes in the defect structure. All of the above
methods use catalytic activation of nickel in the presence of CO.
However, it can be readily appreciated that processes that at atmospheric
pressure can produce nickel, particularly, activated nickel for subsequent
reaction
with CO at atmospheric pressure would provide signif cant capital and
operating cost
advantages.
Further, it can also be appreciated that processes that enable Ni(CO)4 to be
manufactured at a su~cient rate as to obviate the need for storage in order to
build up
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CA 02461624 2004-03-22
a sui~tcient supply for practical, eilxcient use in a subsequent nickel
deposition
process, would also offer significant capital and operating cost savings. To-
date, in
commercial operations rate limitations on the production of Ni(CO)4 require
such
storage facilities and operations.
S There is, thus, a desire for an improved method of Ni(CO)4 production which
is operable at atmospheric pr~essm~e and which is of a sufficient rate as to
negate the
need for storage of the Ni(CO)4 prior to use in a subsequent decomposition
and/or
deposition process.
PUBLICATIQNS
1. Morton J.R., Preston K. F. J. Clam. Phys., 81, S6, (1984).
2. Morton J.R., Preston K. F. luorg. Chem., 24, 3317, (1985).
3. Mercer D. L.; Into Ltd. (Can. 1038169 (1975/78]).
1 S 4. Schafer H. ~ Anorg Allg. Chem. 493, 17 ( 1982).
5. Job R. J. Chem. Educ. 56, S56 (1979).
6. Mazurek H., Mehta R. S., Dresselhaus M. S., Dresselhaus G., Zeiger H. J.
Surf. Sci. 118, S30 (1982).
7. Korenev A. V., Shvartsman R. A., Mnukhin A. S., Tsvetn. Met. 1979 Nol l,
pp. 37.
8. Mehta R. S., Dresselhaus M. S., Dresselhaus G., Zeiger H. J. Surf. Sci. 78,
L681 ( 1978).
9. Greiner G., Manzel D. J. Caxal. 77 382 (1982).
2S SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for the
commercial
production of Ni(CO)4 from a source of nickel in an efficacious manner at
atmospheric pressure, with resultant capital and operating cost savings.
It is a further object of the present invention to provide a process and
apparatus for the commercial continuous production of Ni(CO)4 from a source of
nickel at a sufficiently high rate as to negate the need for storage of the
Ni(CO)4 prior
to a subsequent decomposition step, with resultant capital and operating cost
savings.
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CA 02461624 2004-03-22
' Accordingly, in one aspect the invention provides a process for producing
Ni(CO)4 fmm carbon monoxide and a source of nickel selected from the group
consisting of elemental nickel, a nickel compound or mixtures thereof,
provided said
nickel compound is not nickel chloride her se or in admixture with a nickel
carbonate
ore in an amount greater than 50% w/w nickel chloride which process comprises
(a)
treating said nickel source with hydrogen at a pressure of at least
atmospheric pressure
and an effective temperature, in the presence of chloride anion or an ~ situ
generator
thereof precursor; to produce a resultant active nickel; and (b) reacting said
carbon
monoxide with said resultant active nickel to produce said Ni(CO)4.
By the term "resultant active nickel" as used in this specification and claims
is
meant resultant particulate nickel that reacts with CO at essentially
atmospheric
pressure and a temperature of from ambient (20°C) to 80°C to
effect conversion to
Ni(CO)4 at an acceptable conversion rate,
By the term "acceptable conversion rate" is meant herein the rate of
production of Ni(CO)4 in ~e order of at least 0.1 g/hr Ni(CO~ per g/Ni, which
provides an efficacious rate for direct utilization, without the need for a
build-up in
storage, preferably for use in a commercial subsequent deposition process. A
more
acceptable rate is 1 g/hr Ni(CO)4 per g/Ni and a still more advantageous rate
is the
maximum rate of 3.0 g/hr. Ni(CO)4 per g/Ni.
The effective temperature is a temperature which ,effects the production of
resultant active nickel at an acceptable rate . of at least atmospheric
pressure.
Preferably, the effective temperature is in the range 300° -
650°C and more preferably,
350°- 550°C.
The Ni(CO)4 produced in step (b) may be collected, or, alternatively, when
made at an acceptable conversion rate, as herein defined, preferably of at
least 0.25
g/hr Ni(CO)4 per g Ni, preferably, at a rate of 3.0 g/hr Ni(CO)4 per g Ni
directly
passed to a deposition chamber for immediate decomposition to Ni and CO. This
enables the CO to be immediately recycled in a close-loop manner as to provide
a
continuous CO closed-loop process.
Accordingly, in a further aspect, the invention provides an improved apparatus
for the production of nickel powder, coatings, articles or compounds from the
decomposition of Ni(CO)4, said apparatus comprising:-
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CA 02461624 2004-03-22
(a) a decomposition chamber having a Ni(CO)4 feed inlet, a spent CO outlet
and adapted to receive a substrate;
(b) a Ni(CO~ production chamber having a CO feed inlet, a gaseous Ni(CO)4
product outlet and adapted to receive source nickel for reaction with CO,
wherein the im~oved apparatus comprises
(i) Ni(CO)4 direct feed means between said Ni(CO)4 feed inlet of said
decomposition chamber for feeding Ni(CO)4 directly from said
production chamber to said decomposition chamber at an acceptable
feed rate:
(ii) CO recycle conduit means between said spent CO outlet and said CO
feed inlet; and
(iii)wherein said source nickel comprises activated nickel produced as
hereinabove defined.
Present prior art processes have very low conversion rates, typically of Iess
than 0.03 g Ni(CO)4 /hr: per glNi, which requires that the Ni(CO)4 needs to be
stored
to a required volume prior to use in a subsequent decomposition or deposition
step.
The nickel compounds of use in the practise of the invention as hereinabove
defined may readily be selected, from, but not limited to, for example, the
group
consisting of a nickel salt, most particularly, nickel chloride, carbonate,
hydroxide,
oxide and metallic elemental nickel. The metallic elemental nickel is most
preferably
in particulate form, for example, as a very fine powder.
The preferred nickel salt is nickel chloride, preferably in the form of a
hydrate,
or a mixture thereof with nickel carbonate in the fonm of zaratite (2Ni(OH~-
NiC03.4H20), preferably wherein the amount of nickel chloride is such as to
produce
20 - 25% W!W of chloride based on nickel in the mixture.
The chloride anion may be selected from, by way of example, but not limited
to, hydrogen chloride and a metallic chloride salt, such as, for example, an
alkali,
alkaline earth or transition metal simple or complex sait, e.g. FeCl3. The
invention
also includes processes that involve the use of precursors of chloride ion
under the
reaction conditions defined, such as, for example, suitable use of C12, oxides
of
chlorine gas and 'OCI3 salts that produce chloride anion in situ.
The chloride anion is, preferably, present at a ratio of at least 1:10 atomic
W/W% Cf to Ni, more preferably 1:5 atomic W/W%.
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CA 02461624 2004-03-22
A preferred process is wherein the chloride anion is present as gaseous
hydrochloric acid in gaseous admixture with the hydrogen, and more preferably,
wherein the nickel compound is first treated with hydrogen at the effective
temperature for a first period of time and subsequently treated with the
gaseous
admixture for a second period of time, at the effective temperature.
The chloride anion in alternative embodiments may be gentratod in situ under
the aforesaid process conditions, according to the invention as defined, in
requisite
effective amounts from chloride anion generating precursors, such as, for
example,
chlorate compounds and chlorine gns.
IO In a further aspect, the invention provides the resultant active nickel
when
made by a process as hereinabove defcned prior to its subsequent reaction with
CO to
form Ni(CO)4.
In a yet further aspect, the invention provides a process as hereinabove
defined
for producing resultant nickel from the decomposition of nickel carbonyl
produced by
I S a process as hereinabove defined.
We have found, further, that relatively small amounts of metal chlorides, e.g.
fendc chloride in the presence of non-chloride nickel compounds enable
activated
nickel to be formed according to the process of the invention as hereinabove
defined.
The bus product stream comprises H2 and HCl and, optionally, H20, C02
20 and CO.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be better understood, preferred embodiments
will now be described by way of example only with reference to the
accompanying
25 drawing, wherein:-
Fig. I is a graph showing overall conversion ('/o) against reaction time (hr.)
for
various processes according to the invention;
Fig. 2 is a diagrammatic flow diagram of a continuous self-contained process
according to the invention; and
30 Fig. 3 is a diagrammatic sketch of a Ni(CO)4 production reaction chamber in
direct
communication with a Ni deposition chamber according to the invention.
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CA 02461624 2004-03-22
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In order that the invention may be better understood, preferred embodiments
will now be described by way of example only, wherein Examples 1 and 2 do not
constitute part of the invention as claimed but are provided for comparison
purposes
only.
Exatgple 1 (Prior Art)
NiC03 powder (200 g) was placed in an extraction reactor and treated with a
stream of H2 gas at 300 rnL/rnin flow rate, at 500°C for 7 hours to
effect substantially
complete reduction. The nickel powder produced was cooled to 100°C and
the
atmosphere of H2 was subsequently replaced with carbon monoxide. The reactor
was
cooled further to 50°C and CO gas passed through at 300 mL/min flow
rate. The
resulting Ni(CO)4 was passed through a pair of carbonyl decomposers according
to
the prior art and nickel was recovered as nickel powder, (10 g; 10 % yield)
after 12
hours.
Example 2 (Prior Art)
Ni(OH}~ powder (100 g) was placed in the extraction reactor and treated with
a stream of H2 gas at 300 mL/min flow, at 500°C for 7 hours to
essentially complete
reduction. The resulting nickel powder was cooled to 100°C in the
atmosphere of H2
which was subsequently replaced with carbon monoxide. The reactor was cooled
down further to 50°C and CO gas passed through at 300 mlr/min flow
rate. The
resulting Ni(CO)4 gas was passed through carbonyl decomposers and nickel
powder
(Gg, 9.5 yield) after 12 hours was recovered.
Examvle 3
300.1g of a nickel carbonate) nickel chloride mixture (10:1 w/w) was placed
into an extraction n~ctor and treated with hydrogen (2L/min) at 450°C
for 6 hours.
Subsequently, the hydrogen was replaced with argon, the reactor cooled to
40°C and
the argon replaced with carbon monoxide at a gas temperature of 80°C,
and flow rate
of 4 L/min. whereby nickel carbonyl was formed, collected and subsequently
decomposed to Ni and CO to provide (1038; 70%) yield of nickel extraction
yield in 6
hr.
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302.3 g of the same mixture as in Example 3 was under similar conditions but
wherein after 0.5 h, the hydrogen gas was doped with 1% of HCI for a further
reaction
period of 4 hours. The subsequent nickel extraction procedure was similar to
Example
3 and gave 134g; 90% yield of nickel in 6 h.
Exain~le 5
300.1 g of nickel carbonate was treated under similar conditions as in Example
4 but wherein after 0.5 h a flow of 900cc/min of HCl gas was introduced into
the
hydrogen flow at 2 L/min for 4 h. The subsequent nickel extraction procedure
was
similar to Example 3 and gave a 96.48 % yield of nickel in 13 h.
The aforesaid examples 3-5 are better illustrated with reference to Fig. 1
wherein:-
Line 1 represents the catbonylation of nickel produced by the reaction of a
mixture of
nickel cacbonate/nickel chloride 10:1. (6 h, 70.4% yield) according to Example
3.
Line 2 represents the same composition according to line 1 plus 1% pf HC1 in
the gas
stream (6 hours, 90.45% yield) according to Example 4; and
Line 3 represents 100% nickel carbonate plus HCl (13 h, 96.48%) according to
Example 5.
The aforesaid examples clearly illustrate the beneficial effect of having
chloride anion present in admixture with a nickel compound in the hydrogen
reactor
in producing a particulate nickel more efficacious in reacting with CO to
produce
Ni(CO),,.
TABLE 1
ExampleNi CompoundEquivalentDepositedTime Rate** Rate***
(g) Ni(g) Ni(g) (hr)*gNi/gNi/hrNi(CO)4
rox. / Ni/hr
# 1 200 (NiC03)98 10 12 0.01 0.3
#2 100 (Ni(OH2))63 6 12 0.01 0.03
#3 300 NiC03 147 103 6 0.12 0.36
/
Ni C12 (10:1)
#4 302 NiC03 148 134 6 0.15 0.45
/
Ni C12 (10:1)
#5 300 g NiC03148 142 13 0.07 0.21
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* carbonylation and subsequent decomposition time from treated (reduced) Ni.
** rate of deposition of Ni metal per se per hour per 1 gm equivalent Ni,
calculated ~ from Ni compound starting material.
* * * Rate of production of Ni(CO)4 per hr. per g Ni.
Table 1 shows the beneficial enhancement in the rate of production of Ni from
its various sources by the process according to the present invention, wherein
the
presence of chloride anion in Examples 3, 4 and 5 shows the very significant
beneficial egect over the abs~ce of chloride anion in Examples l and 2.
This enhancement in production rate of Ni(CO)4 enables the direct use thereof
in any subsequent desired decomposition step. .
Fig. 2 is a diagrammatic flow diagram of a continuous nickel deposition
process self-contained with respect to CO, according to the invention. It
shows
generally as 10, a reaction chamber 12 linked to decomposition chamber 14 by
Ni(CO)4 and CO conduits 16 and 18, respectively.
Chamber 12 contains, alternatively, nickel source 20 and resultant nickel 22;
and has hydrogen feed and outlet/recycle conduits 24 and 26, respectively; HCl
feed
and outlet/recycle conduits 28 and 30, respectively; and Ni(CO)4/CO exit
conduit 16.
Decomposition chamber 14 contains a substrate 32 to be nickel coated from line
16.
In operation, nickel source 20 is treated with hydrogen, typically, at 400-500
°C for S-15 hours and 2 Umin at atmosphere pressure to produce a
reduced nickel
powder 21.
HCl gas at 1 Umin and 50 - 80° is then recycled through chamber
I2,
optionally, with hydrogen, to produce treated nickel powder 22. Chamber 12 is
then
subsequently purged with, for example, argon from conduit 23 and, thereafter,
CO
from conduit 18 is fed into chamber 12, wherein Ni(CO~ is produced and passed
through conduit 16 to decomposition chamber 14. Recycle conduit as shown in
Fig. 2
are utilized as desired.
It can be seen that once the pmcess is operating at "steady state" for an
alternative two-stage operative cycle, that the amount of CO used in the
production of
Ni(CO)4 can be met from ~e decomposition thereof in chamber 14. The process
can
thus be considered as being essentially self-contained with respect to CO.
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Importantly, since the rate of praluction of Ni(CO)4 in chamber 12 is
sufficiently high enough to warrant a direct feed to chamber 14 for
decomposition of
Ni onto substrate 32 in an efficacious manner, no intervening storage facility
is
required. This is of value in commercial operations.
Fig. 3 shows generally as 100 a double chamber apparatus for the continuous
production and decomposition of Ni(CO)4.
Ni(CO)4 production chamber 120 contains activated nickel 140 prepared
according to the invention, either in an initial starting amount as shown in
this
embodiment or under continuous feed means of an alternative embodiment (not
shown). Chamber 120 has a CO feed inlet 160, whereby in operation CO gas
reacts
with nickel 140 to produce Ni(CO)4 at an acceptable production rate selected
from 0.1
to 3.0 gNi(CO)4/g activated Ni/hr.
Decomposition chamber 180 contains a mandrel, mold or like substrate 200
having a substrate surface 220 upon which is deposited Ni as a coating 240
which
constitutes a Ni shelf product in the embodiment shown by decomposition of
gaseous
Ni(CO)4 from chamber 120 fed through conduit 260. By-product CO exits chamber
180 through outlet 280 and is recycled through conduit 300 to feed inlet 160.
The
above process constitutes a continuous, CO self contained system wherein the
Ni(CO)4 is essentially produced in chamber 120 at a rate sufficient to provide
for the
practical deposition operation in chamber 180 as to negate the need for
Ni(CO)4
storage with its attendant capital and operating costs.
Although this disclosure has described and illustrated certain preferred
embodiments of the invention, it is to be understood that the invention is not
restricted
to those particular embodiments. Rather, the invention includes all
embodiments
which are functional or mechanical equivalents of the specific embodiments and
features that have been described and illustrated.
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