Pickling solution for stainless steels
Ecoplus 2000/P is a stainless steel pickling solution with a new formula that does not contain nitric acid. It is used to solve the problems of nitrates in water and NOx in aspirated fumes.
The product is to be used diluted with water at a volume ratio of 1:1 for topping up or as is to strengthen the bath.
Prepare the bath by pouring Ecoplus 2000/P and water into the tank; the first time it is used, activate it with 1-2% of Ox Corrector based on the weight of the bath contents (e.g. a 3000 kg bath requires gradual addition of 30-60 kg of Ox Corrector).
Ox Corrector must be added slowly agitating or homogeneously distributing it in the tank. Adding the corrector too quickly or adding too much corrector will decompose the product causing wastage and a temporary rise in the bath temperature (if this happens, wait for the bath to cool before starting pickling).
Instructions for use
The product is to be used diluted with water at a volume ratio of 1:1. Chemical treatments in general are not effective if oils and greases are not first removed. It is advisable to pre-treat the surfaces with a liquid degreaser; good degreasing is an essential requirement to obtain a good result.
Application is normally by immersion in PP/PVC tanks and a fume extraction system has to installed [it is advisable to use PTFE (Teflon) heating elements to heat the solution].
Ecoplus 2000/P needs continuous addition of Ox Corrector (hydrogen peroxide-based) during the treatment; we advise you to use a metering pump.
The piece must be fully immersed and it is advisable to move it a few times during the treatment or to move the bath using an antacid pump. After a sufficient time for good pickling, remove the piece from the bath, let it drain, and then place it in the washing tank or station equipped with a pressure washer.
The treatment time varies depending on the operating temperature, welding quality, steel thickness, concentration of components in the bath etc. The times for a standard treatment at 28°C are as follows:
- AISI 304: 2-3 hours
- AISI 316: 3-4 hours
- Duplex: 6-8 hours
- Superduplex: 12 hours (overnight)
It is advisable to do some tests on samples in order to determine the exact time.
After pickling the pieces, give them another good wash at high pressure. A final wash with demineralised water allows obtaining an excellent result. After pickling, you can also use ECOCLEAN 2000, a detergent for stainless steel, to prevent haloes and marks.
Bath maintenance conditions
The most important parameter to keep under control is the content of stabilised hydrogen peroxide: too little or too much may cause the piece to colour.
You should add stabilised hydrogen peroxide before starting every work cycle if you work intermittently; otherwise, you can add it continuously with a metering pump.
The correct dosage of hydrogen peroxide can be efficiently checked by using a portable redox meter (PC01269) to check that the value is approximately 400 mV. This value can be reduced to about 330-380 mV in automatic systems.
Temperature is another important parameter to be kept under control. It is advisable to work at temperatures below 30°C bearing in mind that the immersion times are longer when working at room temperature. Approximately 25°C is an excellent operating temperature.
For good functioning of the bath, it should be kept moving with an antacid pump.
One of the strengths of this bath is that there is no sludge formation on the bottom of the tank except when treating annealed pieces.
To remove the supernatant oil of the bath, you can install our disc oil extractor (IP06452).
You should regularly have the efficiency of the bath checked by sending a sample to our laboratory, which will check the iron content and the correct ratio of elements contained, and give you information on any corrections to be made.
Precautions for use
Use appropriate PPE and follow the instructions on the safety data sheet.
The washing water is acidic and may therefore not be drained directly, but has to be neutralised and decanted.
Industrial wastewater may be drained only after authorisation by the competent authorities. Delmet can supply manual or automatic equipment for this type of treatment.
Ecoplus 2000/P pickling solution is available in the following sizes:
- ECOPLUS 2000/P - pack of 50 kg (PC00109)
- ECOPLUS 2000/P - pack of 1000 kg (PC00110)