Phosphoric acid, as an important basic chemical raw material, is widely used in fertilizer production, food processing, electronics manufacturing, and the pharmaceutical industry. With the increasing demands for higher purity phosphoric acid from downstream industries, traditional phosphoric acid purification processes face numerous challenges, including low efficiency, high energy consumption, and unstable product quality. Against this backdrop, Zhengzhou Tiei Extraction centrifugal extraction technology, with its efficient mass transfer and precise separation characteristics, offers a new pathway for phosphoric acid purification.
Challenges of Traditional Phosphoric Acid Purification Processes
In phosphoric acid production, wet-process phosphoric acid is widely used due to its lower cost, but it contains a large number of metal ions (such as iron, magnesium, aluminum, and calcium) and sulfate ions as impurities. Although traditional solvent extraction methods can effectively remove these impurities, they often encounter the following problems in practical operation:
1.Low extraction efficiency: Traditional mixer-settler equipment is bulky, and mass transfer efficiency is limited, resulting in a large number of extraction stages and a long process flow.
2.Unsatisfactory separation effect: Incomplete two-phase separation easily leads to cross-contamination, affecting product purity.
3.High operating costs: The equipment occupies a large area, solvent entrainment losses are significant, and energy consumption is high.
4.Complex operation and maintenance: The equipment is prone to clogging, difficult to clean, and has a low degree of automation.
Technical Advantages of Tiei Extraction CWL-M Centrifugal Extractor
Zhengzhou Tiei Extraction's CWL-M series centrifugal extractor has been comprehensively optimized to address the aforementioned issues, with its core advantages including:
1.High-efficiency mass transfer and rapid separation: Utilizing a high-speed centrifugal force field, the two-phase liquids are thoroughly mixed and contacted during countercurrent flow, greatly improving mass transfer efficiency; simultaneously, density differences are used to achieve millisecond-level rapid separation, significantly shortening process time.
2.Precise control and stable operation: The unique fluid dynamics design, coupled with a precision control system, allows for precise control of phase ratio, residence time, and mixing intensity, ensuring stable process parameters and consistent product quality.
3.Compact design and energy efficiency: The modular design significantly reduces the equipment footprint; closed-loop operation effectively reduces solvent volatilization and product loss; low-energy motors and optimized fluid path design reduce operating costs.
4.Corrosion resistance and easy maintenance: Parts in contact with materials are made of high-strength corrosion-resistant materials (such as Hastelloy, special coatings, etc.), adapting to the harsh environment of phosphoric acid production; the equipment structure is simple, facilitating online cleaning and maintenance.
Innovative Process Flow for Phosphoric Acid Purification Using the CWL-M Centrifugal Extractor
The phosphoric acid purification process based on the CWL-M centrifugal extractor represents a comprehensive upgrade over traditional methods. The following is a detailed description of the process flow:
1.Pre-treatment and Feeding
Crude phosphoric acid is first subjected to preliminary filtration to remove solid suspended matter. Subsequently, it is precisely metered with a specific ratio of extractant (typically organic phosphate esters or amine solvents) and fed into the CWL-M centrifugal extractor. The key to this stage is the precise control of the two-phase ratio and feed temperature, creating optimal conditions for efficient extraction.
2.Multi-stage Countercurrent Centrifugal Extraction
- The pre-treated mixture enters the CWL-M centrifugal extractor and undergoes the following high-efficiency processes:
- High-efficiency mixing: Inside the high-speed rotating drum, the two-phase liquids are intensely sheared to form tiny droplets, greatly increasing the mass transfer surface area. Compared to traditional methods, mass transfer efficiency is increased by 3-5 times.
- Rapid separation: The mixture then enters the separation zone, where under the action of strong centrifugal force (typically 1000-5000g), the heavy phase (phosphoric acid phase enriched with impurities) and the light phase (extractant phase rich in the target substance) are completely separated within milliseconds, achieving a separation efficiency of over 99.9%.
- Multi-stage countercurrent configuration: Multiple CWL-M centrifugal extractors can be flexibly combined into a multi-stage countercurrent extraction system. After each extraction stage, the two phases enter the adjacent stages for further purification. This configuration significantly reduces the amount of extractant used while increasing the recovery rate of the target product.
3.Stripping and Regeneration
The extractant phase loaded with phosphoric acid enters the stripping section, where it contacts a small amount of back-extractant (typically deionized water or dilute acid solution), achieving the transfer of phosphoric acid from the organic phase to the aqueous phase in the CWL-M centrifugal extractor. The organic phase after stripping can be recycled after simple regeneration, significantly reducing solvent consumption and operating costs.
4.Post-processing and Product Refining
The high-purity phosphoric acid solution obtained from stripping then enters the subsequent processing unit, which may include:
Decolorization treatment: Removal of trace organic impurities through activated carbon adsorption.
Concentration and crystallization: Further concentration or preparation of high-purity phosphoric acid crystals as needed.
Solvent recovery: Advanced recovery systems ensure efficient recycling of organic solvents and reduce emissions.
Application Case
A purification and upgrading project for a large phosphorus chemical company
The company's original phosphoric acid purification system used traditional mixer settlers, facing problems such as unstable product purity (fluctuating between 95-98%), high solvent consumption, and high wastewater treatment costs. After introducing the CWL-M centrifugal extraction system:
The phosphoric acid product purity was stably increased to over 99.5%.
Extractant consumption was reduced by 40%, saving over 3 million RMB annually.
Wastewater discharge was reduced by 40%, saving over 3 million RMB annually.
Wastewater discharge was reduced by 60%, significantly alleviating environmental pressure.
Equipment footprint was reduced by 70%, creating conditions for production line expansion.
The green development of the phosphoric acid purification industry requires innovation in equipment. Zhengzhou Tiei Extraction's CWL-M centrifugal extractor, through its efficient separation, anti-emulsification, corrosion resistance, and modular design, provides the industry with a systematic solution ranging from process optimization to cost control.
Email: sales@tieiextraction.com
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