Chromate  Pollution  Needs  to  Be Cured  by  "Foreign Doctors"
                        By Zhou Yue
1. Production status
The chromate industry in China which  was  started  in  1958  used  the
production and experience of former USSR in the 50's and  adopted  the
calcination process in calcium filling powder kilns.
The distribution  of  domestic  chromate  producers  is  not  rational.
According to statistics in 1996, there were 24 producers in  operation
distributed in 16 provinces and municipalities.  These  producers  are
great in number but small in size and located in big and medium cities
. The capacity of most producers is 3 000 - 7 000 t/a. The capacity  of
some small producers is even less than  1  000  t/a.   The  number  of
producers with a capacity of over 10 000 t/a is only 4.
  Based on the chromate output of 120 000 tons in 1996, the  amount  of
residues accumulated in the chromate  production  from  1958  to  1996
already reached 3.3 million tons. However, most of storage yards  have
not taken any seepage prevention and some storage yards have  gone  so
far as to put the residues anywhere they like.  The  annual  discharge
amount of waste water is around 800 000 tons.   The  annual  discharge
amount of chromate-containing powder also reaches 2 400 tons.  Serious
pollution is caused to the environment.
There are two major problems in the chromate production in China.   One
is the small capacity. The single train capacity is only 10 000 t/a in
China but 30 000 - 50 000 t/a in foreign countries. The other  is  the
large amount of residues. The amount of residues per ton of product is
2.5 - 3.0 tons and the Cr+6 content in the residues is 2.0 - 2.5%, far
exceeding the discharge standard.
The chromate output in China  can  not  meet  the  increasing  domestic
demand for long years. Around 15 000 tons has to be imported each year
to bridge the gap. The chromate capacity in China is expected to reach
160 000 t/a in 2000. Based on the normal operating rate, the  chromate
output will reach 120 000 - 140  000  tons  at  that  time,   and  the
domestic demand can be basically satisfied.
2. Development prospect
Due to the serious pollution of the chromate industry,  some  producers
in China are faced with the reality of being forced to shut down.   If
such a thing does happen, the output of domestic chromates will not be
able to meet the market demand. The macro policy-making departments in
China only have the following two alternatives: (1) rely on 3 000  t/a
pilot units using the calcium-free calcination  process  developed  in
the recent two years to renovate the existing chromate producers; ( 2)
introduce the calcium-free calcination process from  abroad  to  solve
the pollution problem. If the first alternative is selected, both  the
state and enterprises will have to put in large amounts of capital. In
the writer's opinion, the second alternative is the one  which  should
be selected. Reasons for this are as follows:
(1) Foreign companies think highly of the large market in the  chromate
production in China. They hope to construct wholly  foreign- owned  or
joint venture chromate units using the calcium-free calcination process.
It will help develop the domestic chromate production.
(2) The chromate production is a small sector. China has no capital and
energy to solve the pollution problem caused by the chromate production.
Chromate producers have no capacity to do it by themselves.
(3) The construction of wholly foreign-owned or joint venture  chromate
units using the calcium-free calcination process (with a  capacity  of
50 000 t/a)   can  change  the  structure  of  the  existing  chromate
producers in China. Most of producers with a capacity of less than  10
000 t/a will be  shut  down.   Nearly  20  pollution  sources  can  be
eliminated and the amount of chromate residues can be reduced  by  150
000 tons a year.
In case we do not start to make a planned readjustment to the structure
of existing chromate producers in China, there would be a  possibility
of repeating the closure of small paper mills in the Huai River reaches.