In various industrial sectors such as chemical manufacturing, pharmaceuticals, and hydrometallurgy, oxalic acid is widely used as an important raw material and cleaning agent. However, the resulting high-concentration oxalic acid wastewater has become a major challenge for enterprises pursuing sustainable development. Traditional lime neutralization not only leads to severe wastage of valuable oxalic acid resources but also generates large amounts of calcium-containing sludge that is difficult to treat—resulting in high hazardous waste disposal costs and significant environmental pressure for enterprises.
As a leading provider of extraction technology and equipment solutions in China, Tiei Extraction offers an advanced centrifugal extraction process and equipment that provides an efficient, economical, and eco-friendly solution for oxalic acid wastewater resource recovery and wastewater reuse.
Centrifugal Extraction Technology
The core of centrifugal extraction technology lies in utilizing the difference in the distribution coefficient of oxalic acid between the organic solvent and aqueous phases, and realize the rapid transfer and enrichment of oxalic acid from wastewater to extractant through an efficient centrifugal field.
The process is simple and efficient:
Extraction
The oxalic acid-containing wastewater and a specially formulated extractant are fed into the Tiei Extraction CWL-M series centrifugal extractor. Under the high-speed centrifugal force field, the two immiscible liquids are intensely sheared and thoroughly mixed, allowing rapid mass transfer. Oxalic acid transfers from the aqueous phase into the organic phase.
Separation
The centrifugal extractor uses centrifugal force to quickly and thoroughly separate two liquids of similar density, with excellent separation effect and almost no entrainment.
Stripping
The organic phase loaded with oxalic acid is fed into a second-stage centrifugal extractor, where it contacts a stripping agent (such as hot water). The oxalic acid is “washed” back into the aqueous phase, yielding a pure, high-concentration oxalic acid solution.
Reuse
After extraction and purification, the oxalic acid content in wastewater has been reduced to extremely low levels. With simple conditioning, it can be reused in production, significantly reducing new water consumption. The recovered high-concentration oxalic acid solution can be directly returned to the production system or concentrated and crystallized to produce oxalic acid products.
Core Advantages of Centrifugal Extraction Technology
Compared with traditional mixer-settler or extraction column systems, Tiei Extraction’s centrifugal extraction technology offers unparalleled advantages:
- High recovery efficiency and remarkable economic benefits
Oxalic acid recovery rates can exceed 90%, effectively transforming “treatment costs” into “sales profit” or “raw material savings.” The investment payback period is short. - Wastewater reuse for cost reduction and emission control
The treated wastewater can be recycled for industrial use, saving 50%–80% of fresh water consumption. At the same time, total wastewater discharge is greatly reduced, helping enterprises achieve “near-zero emissions.” - Continuous operation with high automation
The fully enclosed continuous counter-current process offers high throughput and a compact footprint. It can be easily integrated into existing production lines with automated control, minimizing manual intervention. - Short residence time and low solvent loss
Materials stay inside the machine for only a few seconds, reducing solvent degradation and evaporation. The superior separation performance minimizes cross-contamination between two-phases, and solvent loss is significantly lower than with conventional equipment. - Easy start-up and shutdown, no clogging issues
The equipment starts quickly, and during shutdown, the self-cleaning function allows for complete drainage of internal materials. It is particularly suitable for handling crystallization-prone or easily emulsified materials, effectively solving the clogging problems common in column-type systems.
Email: sales@tieiextraction.com
Whatsapp: +86 19069612820
