The quality of sodium hypophosphite is determined by raw materials such as yellow phosphorus, caustic soda, lime, and production equipment. The quality of raw materials significantly impacts the quality of the finished sodium hypophosphite product. In particular, indicators such as heavy metals and sulfates are closely related to the quality of raw materials. So, what aspects should be considered in the quality control of raw materials for sodium hypophosphite production? We will briefly explain.

1. If the purity of yellow phosphorus is insufficient, its phosphorus sludge content will be high. The phosphorus sludge contains many harmful components, and the content will be relatively high, directly affecting the quality of the sodium hypophosphite product. Yellow phosphorus quality requirement: content 99.9%.

2. Some harmful substances in the raw materials, such as chlorides and potassium ions, enter the sodium hypophosphite solution. Since there is no effective method to remove them, this directly affects product quality. Caustic soda quality requirements: content≥48%, Cl≤40×10⁻⁶, K≤60×10⁻⁶.

3. The sulfate content in refined lime determines the desulfurization cost during production, and potassium ions also have no effective removal method and directly enter the product. Quality requirements for refined lime: effective calcium oxide content ≥88.0%, chloride ≤0.001%, sulfate≤0.040%, potassium ≤0.010%.

The price of sodium hypophosphite is highly dependent on the quality and grade of the raw materials used. Yunnan yellow phosphorus is of high grade and good appearance, followed by Guizhou. Yellow phosphorus from Hubei and Sichuan has more impurities and lower content, requiring more stringent impurity removal processes during production; otherwise, it is difficult to produce a high-quality finished product.