Isn’t it possible to achieve closed pickling purification?
Thread Content
Today, when the whole society is vigorously promoting energy conservation and emission reduction, as the New Year of 2008 is approaching, there is news that three people died of sewage poisoning from a sulfuric acid plant in Huaihua, Hunan Province, which is regrettable and heartbreaking. As sulfuric acid workers, we should feel a heavy responsibility. The sewage from the sulfuric acid plant mainly comes from the purification sections of pyrite acid production and flue gas acid production. According to statistics, the units using these two methods to produce acid account for about 60% of the total. How many of these devices have achieved closed pickling purification? How many are there or the washing process? Please talk about your own situation, what purification process is used, whether closed pickling is achieved, what problems still exist, and what good ideas and suggestions you have. Communicate with each other and improve together. If through everyone's efforts we can achieve closed pickling and eliminate sewage discharge, it will be a contribution of sulfuric acid workers to society.
There is still an open circuit for dilute acid in closed pickling, which has a greater impact on purification indicators, and the cost of treating dirty acid is high!
In the dilute pickling process, the sewage acid is pumped directly to the ordinary calcium workshop to mix with superphosphate. The pollutants in our factory system are only flue gas and there is no sewage discharge. . . :handshake
The above-mentioned sewage acid treatment methods are not recommended, especially the treatment of high-arsenic pyrite, which is equivalent to passing on pollution!
Our factory also wants to achieve a closed cycle, but the circulating acid concentration is only about 5%, which is difficult to increase! And how to use dilute acid is also very difficult!
It would be great if the purified dilute acid could be used as water for the dry suction system after being defluorinated, and if the exhaust gas from the chimney could be introduced into the system as cold blast, it would be a big leap for the sulfuric acid industry in terms of emission reduction.
Pyrite acid production and flue gas acid production use water washing and purification processes. To produce 1 ton of acid requires the discharge of more than 5 tons of sewage. Although some factories can meet the discharge standards through sewage treatment, other factories secretly discharge without treatment, polluting the environment. If pyrite acid production and flue gas acid production cannot achieve a closed pickling cycle, they will eventually be eliminated. Proper electrostatic precipitating is the key to achieving a closed pickling cycle. Sewage acid is used to produce ordinary calcium, which will not transfer pollution. Phosphate rock inherently contains fluorine, and some are radioactive. High arsenic pyrite is not suitable for sulfuric acid production, and the catalyst will be poisoned.