Environmental Engineering Reference
In-Depth Information
copper electro-refining. Some pre-treatments processes may be required to adapt
the furnaces.
Other minor metals have been also been recovered in copper, zinc and lead
smelters. Recently Nippon Mining & Metals, Co. has developed a new factory to
recover not only PGM but other rare metals in a Hitachi refinery (Jx-Group
2014
).
Indium, nickel, cobalt, antimony, bismuth, selenium and tellurium are recovered in
this plant as well as precious metals. Almost the same treatment manner is found
in other non- ferrous smelters. Non- ferrous metal smelters thus play an important
role for minor rare metals recycling- especially since most minor metals must be
imported into Japan, for refining, conversion and use.
A new concept for a metal recycling system (RtoS: “Reserve to Stock”, “arti-
ficial ore deposit design”) was introduced by Shiratori and Nakamura (
2006
), and
based on the concept of the “Urban mine” (Nanjyo
1988
). If effective recovery sys-
tems are not taken into consideration, rare metals will dissipate all over the world
in the future. In particular, established procedures for collecting, recycling and ex-
tracting Cu, Au, and Ag from WEEE presents the opportunity to also gather rare
metals at the same time. If minor rare metals are separated from WEEE by proper
techniques and are accumulated for recovery, we can consider them as resources.
A possible system for minor rare metals recycling has been suggested which could
be self-supporting economically by devising a collection system and introducing
commercial transactions into the recycling system (Shiratori and Nakamura
2006
).
13.4.2
Recycling Technologies for E-scrap
Metal production from natural ore has had a long history- more than 200 years since
the start of the industrial revolution. The first step is the exploration of ores, fol-
lowed by feasibility study (FS) for mining, mineral dressing and extraction. Man-
made resources (metal scrap and/or waste containing metals) have also been treated
in the same way; and the differences between both approaches can be found in the
early stages as shown in Fig.
13.9
. The exploration, FS and mining correspond to
the material flow analysis of target metals, the collection system and collection of
ΎEŽƋŴĂŮDŜŶŜŶŐ
&^ĨŽƋ
DŜŶŜŶŐ
DŜŶĞƋĂŮ
ƋĞƐƐŜŶŐ
DŽƉŮŽƋĂƟŽŶ
DŜŶŜŶŐ
DŽƚƋĂĐƟŽŶ
ΎHƋĎĂŶDŜŶŜŶŐ
DĂƚĞƋŜĂŮ
&ŮŽǁ
ŶĂŮLJƐŜƐ
WŮĂŶŶŜŶŐ
ĨŽƋ
ŽŮŮĞĐƟŽŶ
WƋĞͲ
DƋĞĂƚŴĞŶƚ
ŽŮŮĞĐƟŽŶ
DŽƚƋĂĐƟŽŶ
Fig. 13.9
Comparison between urban mine development and normal mine development
