Di(2-ethylhexyl)phosphoric acid (D2EHPA)

Properties

♦ Solubility

D2EHPA is soluble in organic solvents such as kerosene, aliphatic hydrocarbons, and aromatic

hydrocarbons. This solubility allows for the formation of organic phases in solvent extraction

systems,enabling the separation of metal ions from aqueous solutions.

♦ Extracting Power

D2EHPA exhibits a high extracting power for a wide range of metal ions, including rare earth elements,

uranium, copper, nickel, and cobalt. It selectively forms complexes with these metal ions, allowing for

their efficient extraction and separation from other impurities.

♦ Acidic Nature

D2EHPA is an acidic extractant due to the presence of the phosphoric acid group. It can protonate metal

ions in the aqueous phase and form water-insoluble metal-D2EHPA complexes, which can be easily separated

from the aqueous solution.

♦ Stability

D2EHPA forms stable complexes with metal ions, enabling the extraction and subsequent recovery of metals.

These complexes are relatively resistant to hydrolysis, which ensures their stability during the extraction process.

♦ Toxicity

D2EHPA is considered toxic and should be handled with care. It can cause skin and eye irritation and should

not be ingested. Proper safety precautions, such as the use of protective equipment, should be followed when

working with D2EHPA.

♦ Degradation

D2EHPA is susceptible to degradation by strong acids and bases. Exposure to acidic or alkaline conditions can

lead to the hydrolysis of D2EHPA and the loss of its extracting properties. Therefore, the pH conditions should

be controlled in solvent extraction processes involving D2EHPA.

♦ Temperature Sensitivity

D2EHPA’s extracting power can be influenced by temperature. Generally, higher temperatures enhance the

extraction efficiency of D2EHPA. However, excessive temperatures can also lead to the degradation of

D2EHPA, impacting its performance.

 

Applications

♦ Metal Extraction

D2EHPA is widely used as an extractant in solvent extraction processes for the separation and recovery

of metals. It is particularly effective in extracting rare earth elements, uranium, copper, nickel, cobalt,

and other metal ions from aqueous solutions. D2EHPA forms complexes with these metals, allowing for

their selective extraction and subsequent purification.

♦ Rare Earth Elements (REEs) Recovery

D2EHPA is extensively employed in the extraction of rare earth elements from their ores or concentrates.

It is used to separate REEs from other impurities in a solvent extraction circuit. D2EHPA’s high selectivity

for REEs enables the efficient recovery and purification of these valuable elements, which are crucial for

numerous technological applications.

♦ Uranium Extraction

D2EHPA plays a vital role in the extraction and purification of uranium, a key fuel material in nuclear

power generation. It is employed in the separation of uranium from other elements in the ore processing

stage. D2EHPA forms stable complexes with uranium ions, enabling their efficient extraction and

subsequent recovery.

♦ Metal Purification

D2EHPA is utilized for the purification of various metals obtained through hydrometallurgical processes.

It helps in separating target metals from impurities, such as other metal ions or radioactive elements.

.D2EHPA’s selective extraction properties aid in obtaining high-purity metals suitable for further industrial

use.

♦ Metal Recycling

D2EHPA is also employed in the recycling of metals from industrial wastes, scrap materials, and electronic

waste. It facilitates the extraction and separation of valuable metals, allowing for their recovery and reuse,

thereby contributing to resource conservation and sustainability.

♦ Analytical Chemistry

D2EHPA is utilized in analytical chemistry as a reagent for the determination of metal ions in aqueous

solutions. It can form colored complexes with certain metal ions, enabling their quantitative analysis

through spectrophotometric or colorimetric methods.

 

Product Process

♦ Raw Materials Preparation:

The two primary raw materials required for D2EHPA production are phosphorus pentoxide (P2O5) and

Isooctanol. These materials need to be prepared and handled according to safety guidelines.

♦ Esterification Reaction:

In a reaction vessel, phosphorus pentoxide (P2O5) is added, followed by the addition of Isooctanol.

The reaction takes place under controlled conditions, typically with heating and stirring. The esterification

reaction occurs between the hydroxyl (-OH) group of Isooctanol and the phosphorus pentoxide, resulting

in the formation of D2EHPA. P2O5 + Isooctanol → Di(2-ethylhexyl)phosphoric acid (D2EHPA)

♦ Reaction Monitoring:

During the reaction, the temperature, reaction time, and other parameters are closely monitored

to ensure the desired conversion and product quality.

♦ Workup and Purification:

After the completion of the esterification reaction, the reaction mixture is subjected to a workup

process. This typically involves neutralization of excess phosphorus pentoxide and removal of impurities

through processes such as washing, filtration, and distillation. The purification steps help in obtaining a

high-purity D2EHPA product.

♦ Final Product Storage and Packaging:

The purified D2EHPA is then stored in suitable containers, following proper labeling and safety procedures.

It is typically packaged and transported for commercial distribution and use.

 

Inspection

♦ Inspection process

1. Incoming inspection: The main raw materials,are inspected for their content, appearance and other main

properties.

2. Feeding inspection: the principle of raw material feeding is first-in-first-out, and the appearance of the main

raw materials is randomly inspected according to whether there is a big change in the storage conditions before

feeding.

3. Batch sampling in the production process: During the production process, the main indexes of each batch of

products: content and acid value will be examined three times in different time periods.

4. Storage Inspection: Each batch (5.6tons) is inspected before storage.

5. Outbound inspection: According to the quantity demanded by customers, the products will be sampled

and inspected.

6. Pre-shipment inspection: according to customer’s requirement, third party inspection can be carried

out on the products before shipment.

♦ Inspection Method

Physical Appearance: Visual inspection

Purity Analysis:Gas chromatography (GC)

Acid Value:Potentiometric titration

Water Content:Moisture analyzers

Refractive Index:Refractometer

Density:Density meter

Marking, packaging, shipping and storage

♦ Marking

Each batch of products should be accompanied by a certificate of conformity, including: the name of the

manufacturer, the name of the product, the production batch number, the net weight per barrel, the quality

level and the implementation of the standard number.weight, quality grade and implementation standard

number.

♦ Packing

Packed in clean and dry plastic drums, net weight 200±0.3kg per drum or 1000±0.5kg, compressed and sealed

after each batch.

♦ Transportation

This product is packed in plastic drums, during transportation and loading/unloading, it should be carefully and

gently put down, and prevent from impact.

♦ Storage

The storage place should be cool, dry and ventilated. Do fireproof and rainproof.