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For most of the inorganic salt products
in China, supply has exceeded demand or supply and demand
have reached balance, but few of the products still need to
be imported. Currently the capacity and output of more than
ten products have exceeded demand, including barium carbonate,
sodium sulfide, anhydrous sodium sulfate, etc. The supply
of sodium cyanide, sodium bichromate, etc. has fallen short
of demand. But for most of the products supply and demand
have reached balance. In recent years, about 200 products
have been exported from China with an export volume of about
6,000,000 tons.
With the development of national economy
and improvement of people's living standard, China has developed
many new products in recent years, such as laminate sodium
silicate that meets the requirements for phosphor restriction
or phosphor prohibition in detergents. Globular nickelous
hydroxide, the electrode material of nickel-hydrogen battery,
and superfine silicon dioxide, titanium dioxide and calcium
carbonate, etc. have been put into mass production.
ECEC has participated in the engineering
consultation, design, technology import, technology development
and science & technology brainstorming, etc. of many domestic
and foreign inorganic salt products and played an important
role in industries of nanometer-grade calcium carbonate, sodium
bichromate and potassium nitrate, etc.
Typical projects in this field undertaken
by ECEC include: Anhui Chaohu Chaodong 10kt/a nanometer-grade
calcium carbonate project; 10t/d lithopone project of Pakistan
Sihara Chemical Complex; 20kt/a sodium bichromate project
of Chongqing Pesticide Chemical Industry (Group) Co., Ltd.,
etc.
Sample project:
The process package of 20kt/a sodium bichromate
project of Chongqing Pesticide Chemical Industry (Group) Co.,
Ltd. was introduced from Baltimore Manufacturing Plant of
Allied-Signal Inc., USA, and the basic engineering design
and detailed engineering design for this project were undertaken
by ECEC. In 1998, the plant was put into operation with the
main products of sodium bichromate dihydrate, anhydrous sodium
bichromate, anhydrous chromic acid and basic chromium sulfate,
their quality indexes have reached the international advanced
level.
Technical characteristics of the plant: the
plant has realized large scale, continuous production and
DCS control of the entire flow. It has top-level technical
and economic indexes in China. Residue discharge is only half
of that of the traditional process in China, and there is
no wastewater discharge. It was equipped with complete utilities
and wastes treatment facilities.
Main process features: The conversion rate
of the two-stage aluminum-fixing roasting process exceeds
92%, and neutralization is not necessary to remove aluminum
in subsequent process since its content in yellow liquor is
very low;
Full automatic leaching production line of mobile tanks with
leaching rate of 99%;
Continuous acidification treatment, automatic control of acidification
rate;
Three-effect forced circulation evaporation with high evaporation
efficiency;
Continuous crystallization, controllable particle size of
crystals;
The controlled drying of sodium bichromate dihydrate makes
the product unlikely to cake during its storage, handling
and use;
Exclusive production of anhydrous sodium bichromate in China,
with evident market advantage;
Continuous anhydrous chromic acid production process, low
unit product consumption, high production efficiency and first
class product quality;
Stable plant production, zero discharge of wastewater during
normal operation. |
