Environmental Engineering Reference
In-Depth Information
supports for light bulbs, metal-working dies, furnace parts and as Mo cathodes in special
electrical applications. In fact, the list of products available on the market, which contain
various amounts of Mo, is rather long. Detailed accounts of Mo recovery and recycling in US
prior 1998 were given by Blossom
[702]
.
A boom in Mo demand may result from the international maritime regulations, which ask for
decommissioning of all tankers built before 1987 by 2010. Moreover, a worldwide boom in
construction of crude oil and natural gas pipelines may cause shortages in Mo supply. It is not
easy to make an estimate of these markets. For example, some constructions of pipelines are
being announced without any anticipation of public.
Molybdenum prices increased sharply in the middle of 2002 before being sustained at around
$ US 12 per kilogram through 2003. Subsequently, temporary closure of mines in China
pushed prices slowly above $ US 16 per kilogram. According to the Price-Waterhouse-Coopers
survey, the Mo net revenues showed the most significant annual growth in 2004, i.e., increase
by 209%. During this period, the average Mo price rose from about $ US 14 to almost 40 per
kilogram. In 2005, price was in the range of $ US 70 per kilogram. It was predicted that in the
following years price would increase by about 20%. In early 2008, the price (molyoxide) was
about $ US 70 per kilogram.
12.2 Tungsten
Compared with Mo, the information on W recovery from spent hydroprocessing catalysts is
rather limited although the role of the latter during catalysis may be similar as that of Mo.
Apparently, the methods, which are used for the recovery of Mo, can be applied to that of W.
Historically, the W prices fluctuated widely as the market alternated between periods of
scarcity and oversupply
[703]
. Thus, since 1990 to 2000 the price fluctuated between $ US 4
and 13 per kilogram, whereas in 2000 the price fluctuated between $ US 6 and 13 per
kilogram. It is unlikely that the price of W will approach that of Mo in a near future.
12.3 Nickel
Nickel is used in a wide range of applications as part of the stainless steels, non-ferrous alloys,
and superalloys and in electroplating. In the US (2001), stainless steels and related alloys
applications approached 40% of the total use of Ni. A similar amount of Ni was used in
non-ferrous alloys and superalloys. As alloying component, Ni plays an important role in
chemical, petroleum and aerospace industries. Also, Ni is an active constituent of various
catalysts, i.e., hydroprocessing, hydrogenation, dehydrogenation, hydroisomerization,
dewaxing, etc. As far as the end-use sectors are concerned, commercial, industrial,
transportation and construction materials account for about 29, 27, 24 and 20% of Ni
utilization, respectively.
