The use of boron waste clay to improve the geotechnical properties of a high plasticity clay

Boron minerals containing varying proportions of boron oxide are widely used in industry. Seventy-three percent of the world's known boron mineral reserves are in Turkey. When extracting boron minerals, clay-containing wastes are produced in addition to boron oxide. An increase in the extraction of boron minerals therefore leads to an increase in the boron waste clays. In Turkey, nearly 600,000 tons of boron waste are generated annually. These waste clays cause environmental problems like leaching and groundwater pollution, and their storage causes problems for boron production plants. This study aimed to evaluate whether the addition of boron waste clays improves some geotechnical properties of a high plasticity clay. Standard Proctor tests and tests of consistency limits, unconfined compression, swelling pressure, and permeability were performed on high plasticity clay containing various percentages of boron waste clays (0%, 10%, 30%, 50%, 70%). The test results showed that Bigadic boron waste clay improved the geotechnical properties of the high plasticity clay. The liquid limit of the clay decreased by 27%, 24%, 25%, and 30% when the boron waste percentages were 10%, 30%, 50%, and 70%, respectively. The unconfined compressive strength values of clay with 50% boron waste increased by 35% compared to clay with 0% boron waste. However, 70% boron waste decreased the unconfined compressive strength of the clay. The test results showed that the swelling pressure and hydraulic conductivity values of clays containing boron waste are lower.