Evaporation and crystallization of sodium chloride and sodium sulfate mine water in a copper mine in Yunnan
Sodium sulfate MVR Evaporation Crystallization Project
The organic matter of high salinity organic wastewater varies greatly according to the production process, and the types and chemical properties of the organic matter are quite different.The salt substances are mostly Cl-, SO42-, Na+, Ca2+ ,etc. If it is directly discharged, it has a great impact on the environment; and it is difficult to handle in the biochemical treatment process. These ions are essential nutrients for microbial growth, which can promote enzyme reaction and maintain membrane balance and regulate osmotic pressure.However,if these ion concentrations are too high, it will inhibit and toxic the microorganisms. High salt concentration, high osmotic pressure will cause dehydration of microbial cells and protoplast separation; salting out reduces dehydrogenase activity; high chloride ion has toxic effect on bacteria; High salt concentration and increased density of wastewater will let the the active mud to float and drain, which seriously affects the purification effect of the biological treatment system.
For high salt water, it mainly comes from the following aspects:
1. High-salt wastewater from chemical production processes;
2. From chemical wastewater treatment;
3. High-salt wastewater from freshwater recycling process.
For Sodium sulfate high salt water, the solubility of the material is low, and the boiling point is lower in the case of saturated solubility.The boiling point under atmospheric pressure is low, which is suitable for MVR evaporation. The physical properties of the data are as follows:
Sodium sulfate solubility
|
Item |
Maximum dissolved mass / g in 100g water at the following temperatures |
|||||||||||
|
0 |
10 |
20 |
25 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
|
|
Sodium sulfate |
4.5 |
9.6 |
10.2 |
27.9 |
40.8 |
48.4 |
46.7 |
45.3 |
44.1 |
43.7 |
43.9 |
42.3 |
Sodium sulfate boiling point
|
Item |
Boiling point / ℃ of the solution at the following concentrations (g / 100g water) |
||||||
|
10 |
25 |
40.7 |
50 |
75 |
100 |
222 |
|
|
Sodium sulfate |
100.6 |
101.6 |
|
|
|
|
|
Project
|
No |
Item |
Introduction |
|
1 |
Name |
Evaporation and crystallization of sodium chloride and sodium sulfate mine water in a copper mine in Yunnan |
|
2 |
Address |
Yunnan |
|
3 |
Treatment of wastewater industry |
Copper mine water |
|
4 |
Capacity |
6Ton/hour |
|
5 |
Process Technology |
Membrane concentration + MVR evaporation crystallization (sodium sulfate salt) + MVR evaporation (mixed salt) |
|
6 |
Process introduction |
The project is the evaporation and crystallization of concentrated water after membrane of the copper mine wastewater. The main salt in the raw water is sodium sulfate and sodium chloride is only a small amount.Taking into account the subsequent salt treatment problems of the owner, two-effect MVR evaporation crystallization is selected.In the mixed salt system of sodium sulfate and sodium chloride, the first effect MVR carry out thermal crystallization of sodium sulphate and the salt is anhydrous sodium sulphate which can meet secondary qualified product standard.The second-effect salt is mixed salt of sodium chloride and sodium sulfate.By two-effect MVR evaporation crystallization, the salt different concentration is fully used and high quality is achieved, which reduces the cost of subsequent treatment for the owner.The condensed water reaches the discharge standard. |
