What Is Potassium Chloride?
Potassium chloride is a compound of potassium and chlorine.
It is a colorless crystal or white crystalline powder. It is also known as potassium chloride, potassium chloride, or potassium chloride.
Potassium chloride can be industrially purified from natural ores such as potassium salt (Sylvite), carnallite, and silvinite. Potassium chloride can be produced by the continuous melting method or the flotation method, and highly purified potassium chloride is not deliquescent.
Uses of Potassium Chloride
Potassium chloride has a high safety profile and is approved for use as a food additive. Specifically, it can be used as a substitute for salt (sodium chloride) in many foods, including seasonings, low-sodium foods, and soft drinks. Supplements are also manufactured to provide potassium, an essential mineral.
In the medical field, it is also used as a potassium supplement (oral or intravenous solution) for hypokalemia. In agriculture, it can be used as a fertilizer. Furthermore, electrolyzed hypochlorite water, which is used to sterilize crops, is made by electrolyzing potassium chloride solution.
When potassium chloride is electrolyzed, potassium hydroxide is produced along with hydrogen and chlorine. Potassium hydroxide can be used as a raw material for soap and other chemical products, making it possible to use potassium chloride as a chemical raw material.
Potassium chloride is also used as a drilling fluid when drilling for natural gas or oil. It is called KCl polymer mud and was developed around 1980.
Properties of Potassium Chloride
The chemical properties of potassium chloride are similar to those of sodium chloride. It is easily soluble in water and endothermically soluble in polar solvents. It is virtually insoluble in ethanol and diethyl ether.
Its melting point is 776°C and its boiling point is 1,505°C. It tastes salty and has a distinctive bitter taste. It is nonflammable and less toxic. The Fire Service Law and the Poisonous and Deleterious Substances Control Law do not apply to it. However, care should be taken when storing it at high temperatures.
Structure of Potassium Chloride
Potassium chloride is a chloride of potassium, with the chemical formula KCl. In an aqueous solution, it is ionized into chloride ions (Cl–) and potassium ions (K+). pH is approximately 7.
The crystal lattice has a sodium chloride-type structure. The coordination number is 6, the distance between potassium and chlorine (K-Cl) is 0.314 nm, and the lattice constant is a = 6.278Å. Its molar mass is 74.551 g/mol and its density is 1.987 g/cm3.
Other Information on Potassium Chloride
1. Manufacturing Process of Potassium Chloride
Potassium chloride is produced by the neutralization reaction of hydrochloric acid and potassium hydroxide. Industrially, the mineral product is refined. One method of purification uses solubility differences. The mixture is dissolved in water and crystallized continuously as the water evaporates. The disadvantage, however, is that it requires a lot of energy for heating and is expensive.
If you want to save more cost, the flotation beneficiation method is recommended. First, saturated brine is added to the mixture. Then, air is blown into the suspension to selectively attach potassium chloride crystals to the bubbles, and the bubbles are scooped out. Sodium chloride crystals precipitated at the bottom can also be recovered.
2. Naturally Occurring Potassium Chloride
Plants use potassium as a nutrient. Therefore, potassium chloride is found in algal salt produced by burning seaweed, and ash salt produced by burning inland plants. In addition to that, it is one of the constituents of bittern, which is produced when sea salt is made.
In nature, it is produced as potash ore. Besides precipitating from salt lakes and seawater trapped inland to form deposits, crystals are also obtained from volcanic fumaroles. The main production area in Japan is Chiba. Seawater contains about 0.08% potassium chloride. It can also be extracted from seaweeds, but Japan imports most of its potassium chloride.