Ball clay and alkaline feldspars (syenite and nepheline syenite) were mixed with red kaolinite clay (rich in iron oxides but poor in fluxing oxides) and fired (1000°C - 1200°C) in order to improve certain characteri...
A primary soil-forming process can take place on the concentration waste of apatite-nepheline ores, whose biological recultivation was carried out more than 40 years ago. This process is characterized by the following...