Phosphoric Acid Description
Phosphoric acid, also known as orthophosphoric acid, is a common inorganic acid with the chemical formula H3PO4. The appearance is colorless transparent or slightly yellowish viscous liquid. It has acid properties and is a medium-strong acid. Its acidity is weaker than hydrochloric acid, sulfuric acid, and nitric acid, but stronger than acetic acid, boric acid, etc. Non-volatile, not easily decomposed, almost non-oxidizing, not highly corrosive. So it is a relatively safe acid. But it easily deliquesces in the air. As an important chemical raw material, phosphoric acid is widely used in agriculture, food, medicine, chemical industry and other fields.
| Item | Index | |||
|---|---|---|---|---|
| Food Grade Phosphoric Acid 75%/85% | Tech Grade Phosphoric Acid 75%/85% | |||
| Color/Hazen ≤ | 20 | 20 | 30 | 30 |
| Phosphoric acid (H3PO4) content, % ≥ | 85 | 75 | 85 | 75 |
| Arsenic (As) content, % ≤ | 5.0E-5 | 5.0E-5 | 0.005 | 0.005 |
| Fluorine (F) content, % ≤ | 0.001 | 0.001 | — | — |
| Heavy metal (Pb) content, % ≤ | 0.0005 | 0.0005 | 0.001 | 0.001 |
| (Fe) % ≤ | — | — | 0.002 | 0.002 |
| Easily oxidized substances (H3PO3) content, % ≤ | 0.012 | 0.012 | — | — |
| (CL) % ≤ | — | — | 0.0005 | 0.0005 |
| (SO4), % ≤ | — | — | 0.005 | 0.005 |
The food grade phosphoric acid can be mainly used to prepare phosphate additives. Its purpose is to improve the taste and texture of food, as well as to increase the nutritional value of food. The following is its detailed introduction in food industry:
According to different production processes, the production methods of phosphoric acid can be divided into thermal phosphoric acid, wet phosphoric acid and extraction method to produce phosphoric acid. Below is a detailed introduction to these production methods:
Thermal phosphoric acid. It refers to converting phosphate in phosphate rock into soluble sulfate under high temperature and high pressure conditions, and then obtaining phosphoric acid through steps such as extraction and concentration. The phosphoric acid produced by this method has the advantages of high product purity and stable quality, but it requires a large amount of energy and equipment investment, so the production cost is high.
Wet phosphoric acid. This method refers to the use of dilute sulfuric acid to decompose phosphate rock, and then the resulting phosphoric acid solution is concentrated and crystallized to obtain phosphoric acid. This method has the advantages of simple equipment and low energy consumption, but the purity of phosphoric acid is low and requires treatment to reach higher quality standards.
Extraction method. The production of phosphoric acid by extraction method refers to using an extraction agent to convert the phosphate in the phosphate rock into soluble organic phosphate, and then going through steps such as back-extraction and concentration to obtain phosphoric acid. Although this method of producing phosphoric acid has the advantages of high purity and stable quality, it requires auxiliary materials such as extraction agents and organic solvents, so the production cost is high.