Researchers have discovered ways to enhance the quality of potassium chloride in fertilizers and food additives.

The article has been published in the journal "South Siberian Scientific Bulletin." The research was conducted as part of the strategic academic leadership program "Priority 2030."

Potasium chloride is used to produce potassium fertilizers, as it is essential for plants and participates in photosynthesis, nutrient transport, and water balance regulation. In the oil and gas and mining industries, it is utilized for drilling fluids. In the food industry, it serves as a food additive found in milk, cream, vegetable preserves, cakes, and even sausages. It is also added to table salt to mitigate the "negative" effects of sodium on human health. Therefore, it is crucial to maintain the quality of potassium chloride at every stage of production.

During storage and transportation, the crystals can begin to clump together and absorb moisture. This reduces product quality and can render it unsuitable for transport and storage. An anti-caking agent should reduce the clumping of crystals, but if its composition is not of sufficient quality, its use may actually increase the clumping of KCl powder. Moreover, after its application, potassium chloride may change color from white to light blue. Such a color change does not meet consumer requirements and raises doubts about product quality.

Scientists from Perm Polytechnic University have discovered a way to mitigate the negative effects of anti-caking agents and identified the reasons behind the color change in the powder. The researchers conducted a series of experiments on potassium chloride. To simulate real production conditions, the product was first heated, various anti-caking agents were added, and then stored for periods ranging from one day to 10 days, depending on the treatment applied.

"Typically, three types of anti-caking agents with different compositions are used in production. The experimental results showed that using an amine salt leads to an increased breakdown of the powder's crystals. We recommend using either a hydrochloric acid amine solution or an aqueous solution of yellow blood salt instead," says Konstantin Kuzminykh, a senior lecturer at the Department of Chemical Technologies at PNIPU.

"We also found that the properties of the anti-caking agent with the yellow blood salt solution can be enhanced by adding urea (which is used to make fertilizers): it remains on potassium chloride longer without breaking down even after 10 days of storage. Additionally, due to urea, the powder crystals absorb less moisture, meaning they clump together less," comments Vladimir Poilov, a professor at the Department of Chemical Technologies at PNIPU, and a Doctor of Technical Sciences.

To investigate the cause of the color change in the product after treatment with the anti-caking agent, the researchers conducted a series of experiments. The question was not only why the color changes but also at what point this occurs – during production or afterward. It was found that the powder that changed color was contaminated with sulfur, which gives it the blue hue – 3.53 percent by mass. However, the sulfur content in the anti-caking agent is significantly lower. This indicates that the product degradation occurs not during production but during transportation or even while in storage with consumers. Therefore, scientists recommend storing potassium chloride in a way that prevents contact with acidic environments, such as sulfuric acid.

The scientists from Perm Polytechnic University have determined that treating potassium chloride powder with an anti-caking agent based on an aqueous solution of yellow blood salt can significantly reduce crystal breakdown, ensuring high product standards.