Potassium carbonate is used in pottery and glaze. Glaze is a special type of glass that is made to cover ceramic products. Glazing is different because glass is suitable for shaping bottles or windows. Because it is applied on the ceramic surface and after melting in the furnace, it should create a hard and durable coating. It is very difficult to make the glaze because it does not look like the final product before baking and because we can not directly understand what happens when the glaze melts at high temperatures. We must try to figure out which materials melt at a certain temperature and what happens when the materials are combined. Unglazed ceramics have been around for over 10,000 years. Only in the last 2000 years has glazed ceramics existed, and only in the last 100 years has a scientific approach to making glazes been developed. For this reason, glazes still occupy a mysterious place between science and magic. The first glazes were probably invented in the Middle East, where there are naturally deposits of sodium and potassium compounds (soda ash and pearls) that melt at low temperatures (800 to 1000 ° C). Coincidentally, early potters found that some clays produced a glossy surface when exposed to fire. These self-glazing clays are known as “Egyptian dough”. It is very difficult to make household appliances because they are difficult to shape Applications of Potassium carbonate.
The next step was to develop these materials so that they could be placed on a clay surface to achieve the desired quality from a hard, shiny, easy to clean and durable surface. Since the early potters did not have the technology to reach high baking temperatures, they had to use low melting point materials, mainly sodium, potassium and lead compounds. Glaze development must be done by trial and error, because these early potters had no idea of chemistry. It took a lot of time and effort to naturally make good glazes. These early glazes were often not soft and durable and had problems such as cracking and breaking. In addition, glazes made of lead were toxic to both the potters they worked with and the users. It was only when potters learned to reach high temperatures that truly permanent ceramics were produced. There are other common chemicals and minerals that melt at temperatures above 1100 ° C and form glazes, and clay that burns at this high temperature is also very resistant to water. Today, pearl ash or potassium carbonate is used in pottery and glaze. Potassium carbonate is a white, water-soluble salt that forms a highly alkaline solution. It can be made as a product of the adsorption reaction of potassium hydroxide with carbon dioxide. It has a pleasant property and often looks solid and moist. It is the only material in ceramics that can deliver the required amount of K 2 O without bringing other oxides. The most common source of K 2 O in glaze is feldspar, and typically all the required oxides of feldspar are needed in the glaze (so pure K 2 O is rarely needed and much more expensive). Sometimes it is used to change the color of the glaze. Although a potter does not need to know the different currents, a basic knowledge of the different fluxes is useful in creating experiences when working with glaze. One of the easiest ways to categorize fluxes is by their main component. Potassium flux glazes are more durable than baking soda glazes. Potassium is preferred for high fire glazes. One of the potassium fluxes is potassium carbonate or pearl ash, which is mainly used as a color modifier.