Clay

Clay is a sediment, mainly composed of clay minerals. At a certain amount of water, the clay becomes plastic, whereas after firing it obtains the hardness of the stone. Clay is a widespread, cheap and natural material in the world, as well as in Latvia. It has unique properties, such as the ability to bind various types of pollutants. Clay is traditionally used in the production of refractory materials, ceramics, construction materials (decorative bricks, sewer pipes, wall and floor tiles, etc.), in the cosmetics and pharmaceutical industries. By modifying clay and clay minerals or improving their physicochemical properties (by treatment with organic or inorganic substances), they can be used in the production of innovative materials with high added value. Some of the applications of clay are, as follows:

• in binding of pharmaceutically active substances in waste water treatment plants, which currently cannot be provided by existing filter systems;
• for the capture of greenhouse gases, carbon dioxide;
• recovery of rare earth elements from landfill effluent and their reuse in the manufacture of electronic equipment;
• in smart food packaging as indicators that visually indicate the quality of food;
• in modified drug carrier systems with a controlled release rate of active substances, achieving reduced toxicity and increased drug efficacy.