Separation and recovery of mixed acids
Etching using mixed acids has frequently been used in the manufacturing process of liquid crystal and semiconductors, and the used mixed acid waste was discharged at the same time. In the past, some of these mixed acid wastes have been used for acid cleaning at iron and steel plants, but most have not been used effectively. For example, they were incinerated after being neutralized with a large amount of alkaline. Moreover, phosphorous ore (a raw material for phosphoric acid) relies on imports from overseas, and there is concern about the difficulty in procuring it and prices surging due to export restrictions and currency exchange rates at the country of origin.
With the help of joint development with Kansai University, we have established a technology to separate mixed acid waste and recover them as single acids. The recovered acid can now be used effectively as a resource in reusing and recycling. This technology has been certified a success by the Japan Science and Technology Agency as the "Acid recovery device from mixed acid waste by solvent extraction method".
Sales performance for recycled phosphoric acid
Materials for fertilizers and feed, and active sludge feed
"The waste mixed acids discharged by the liquid crystal and semiconductor industry are actually very clean.
With our unique extraction technology, phosphoric acid is separated from the waste mixed acids and then concentrated and recovered.
The concentration can be adjusted according to requests."
＜Main components＞
| Acetic acid | Nitric acid | AI | Mo | Fe | Sb | Ca | K | Na | |
|---|---|---|---|---|---|---|---|---|---|
| 85% recycled phosphoric acid |
0.08% | N.D. | ～0.5％ | ～0.1％ | 10ppm | 0.3ppm | 1.7ppm | 0.2ppm | 0.1ppm |
| 85% industrial phosphoric acid |
- | - | - | - | 0.7ppm | 1.2ppm | 0.3ppm | 0.1ppm | 0.5ppm |
＜Results for fertilizer＞
| Nitrous acid | Total Cr | Ni | Pb | Cd | As | |
|---|---|---|---|---|---|---|
| 75% recycled phosphoric acid |
< 25ppm | < 1ppm | < 1ppm | < 1ppm | < 1ppm | < 0.1ppm |
Regenerated hydrofluoric and fluorine nitric acid
Surface treatment for glass panels and pickling and surface treatment for iron and steel
We are also recycling fluoric, fluorine nitric, and sulfuric acids that are discharged from the semiconductor industry.
We are mixing waste acids and new solutions as appropriate and selling them.
