Strontium chloride

Strontium Chloride is an inorganic compound with the formula SrCl₂. It is a white or colorless solid that is highly soluble in water, producing a neutral solution. Strontium chloride is used in a variety of applications, including as a precursor to other strontium compounds, in pyrotechnics for the production of red colors, in metal surface treatments, and in medicine as a diagnostic agent in the form of Strontium Chloride Sr 89.

Properties

Strontium chloride exists in both anhydrous (SrCl₂) and hydrated forms, including the dihydrate (SrCl₂·2H₂O). The anhydrous form is a white or colorless crystalline solid that is highly soluble in water and alcohol. It has a melting point of 874°C and boils at 1250°C. The dihydrate is more commonly encountered in laboratory and industrial settings due to its ease of handling and stability.

Production

Strontium chloride is typically produced by treating strontium carbonate (SrCO₃) or strontium hydroxide (Sr(OH)₂) with hydrochloric acid (HCl), resulting in the chloride salt and water or carbon dioxide as by-products:

• SrCO₃ + 2 HCl → SrCl₂ + CO₂ + H₂O
• Sr(OH)₂ + 2 HCl → SrCl₂ + 2 H₂O

Applications

Medicine

In the medical field, strontium chloride is used in the form of Strontium Chloride Sr 89, a radioactive isotope of strontium, as a therapy for metastatic bone cancer. It works by mimicking calcium and targeting bone tissue, delivering radiation directly to the site of cancer.

Pyrotechnics

Strontium chloride is used in pyrotechnics to produce a bright red flame, making it a popular choice for fireworks and flares. The compound is preferred for its ability to produce a vivid color and its relative safety compared to other strontium salts.

Other Uses

Strontium chloride also finds applications in metal surface treatment, where it serves as a flux to remove oxide layers from metals during soldering or welding. Additionally, it is used in the production of strontium-based ceramics and glass products.

Safety

While strontium chloride is generally considered safe for handling, it should be treated with caution. The compound is an irritant to the eyes, skin, and respiratory system. Appropriate personal protective equipment (PPE) should be worn when handling the chemical. Ingestion or inhalation of large amounts can lead to adverse health effects, necessitating the implementation of proper safety measures in workplaces where strontium chloride is used.

Environmental Impact

Strontium chloride is not known to be a significant environmental pollutant. However, as with all chemical compounds, care should be taken to prevent unnecessary release into the environment. Its high solubility in water means that it can easily disperse in aquatic systems, potentially affecting water quality if present in high concentrations.