PROJECT START
2019
COMPLETION DATE
2021
PROJECT OBJECTIVE
Design a sulfuric acid wastewater concentration plant.
To eliminate the discharge of acidic wastewater effluents formed during the titanium dioxide production process into the sludge storage tank.
To obtain a saturated product during the titanium oxide production and send it for concentrated sulfuric acid production.
To return purified water into production.
DESCRIPTION OF THE DECISIONS MADE
The main engineering task in the project’s development was to fulfill the non-typical condition of the Customer – to develop a totally drainless system since the facility is located in an area with fresh water deficiency.
Wastewater treatment and simultaneous sulfuric acid concentration for return into the production process can be achieved using a multiple-effect evaporator station. The company has designed three lines for an installation with a capacity of 600 m3/h, each consisting of six evaporators.
Using multi-effect evaporators (MEE) has significantly reduced heat consumption for evaporation due to secondary steam heat recovery.
A multi-effect evaporator’s operation principle is that evaporation occurs in some interconnected units. The pressure in the units is maintained so that the secondary steam from the preceding stage is used as the heating source in the subsequent one.
The following processes and materials were used to reduce capital expenses for the installation:
The first three stages of the evaporation plant operate with sulfuric acid concentrations ranging from 3.5% to 5.5% by mass at a medium temperature exceeding 80°C. In these conditions, the corrosion-resistant alloy Н70МФВ (ЭП814А) is suitable for use.
In the subsequent stages of the evaporation plant, the temperature is below 80°C with sulfuric acid concentrations ranging from 7% to 20-25% by mass. For these conditions, the corrosion-resistant alloy 06ХН28МДТ (ЭИ943) can be used.
Plant characteristics
Plant capacity based on the feed solution, m3/h: 600
Plant capacity based on the evaporated water, t/h 484
The sulfuric acid concentration in solution after evaporation,% mass 25
Recycling water consumption 6300
Heating steam consumption Р = 0,17 Mpa, t/h 116
– incl.:
– for evaporation of liquid from the feed solution 95
– for feed solution heating 21
Power consumption for two lines, kW/h ~ 1200
ESTIMATED IMPLEMENTATION COST
35 000 000 Euro.
IMPLEMENTATION PERIOD
1 year.
Interested If We Can Deliver an Efficient Solution For Your Manufacturing?