Adsorption of barium on kaolinite, illite and montmorillonite at various ionic strengths

The sorption behaviour of Ba2+ in three different clay minerals from various regions of Turkey has been investigated by means of a tracer technique using Ba-133 in batch experiments. Sorption of Ba2+ on montmorillonite, kaolinite and illite has been studied in mixed solutions of BaCl2 and NaCl at ionic strengths ranging from 1 x 10(-3) M to 1 x 10(-1) M. The L-shape exchange isotherms for Ba2+-Na+ systems are well defined by a Langmuir type equation. The exchange capacity of Ba2+ ions for all three clay minerals increased with decreasing ionic strength

An investigation of crack formation in surface paste disposal method for pyritic Pb–Zn tailings

Surface paste disposal method can be used to minimize environmental risks during storage of mine process tailings. There are some researches and industrial applications which prove success of the method. The surface paste disposal of mineral process tailings obtained from a Pb-Zn underground mine was simulated considering mine site conditions at laboratory scale in the study. The paste material was stored in the cabin/container layer by layer, and then, the cracks occurred after the paste formation of each layer were analyzed by image process. Meanwhile, leachate water collected from the bottom of the cabin was subjected to electrical conductivity (EC) analysis. Furthermore, the wetting-drying process was conducted to simulate the climatic conditions of the region. Additionally, some physical and geochemical parameters such as matric suction, volumetric water content, and oxygen consumption of the paste material were obtained using sensors displaced into different layers. The results of the crack analysis for each layer showed that the cracks intensity increased at lower layers. Moreover, the crack intensity and EC values of each layer showed a similar trend, and the crack intensity increased almost five times during the wetting-drying tests. The measured values of the parameters obtained from the tests indicated that the deposited paste material can be stabile during the deposition over the years under the climatic conditions of the region

Effects of puzzolanic materials in surface paste disposal by pilot-scale tests: observation of physical changes

There are only a few pilot schemes, especially among scientific studies carried out to solve numerous environmental and ecological problems created by water during tailing storage on the surface. It is extremely important to establish precautions that can be taken, especially in the tailing storage process by examining the physical, chemical, mineralogical, and geotechnical changes that develop due to the effect of moisture in the tailing and surface water. In this study, 2 different pilot-scale designs of storage with no additions (reference) and with binder additions (cement and fly ash) to some layers were observed in field conditions for about 1 year to determine the effects of seasonal changes on paste material. The results of the measurements revealed that the water content of the reference design was similar to 10% higher than that of the design with cement addition at the substrates that provide stability and sudden temperature changes at the top layer of the reference design was found to be similar to 35 degrees C. Maximum sudden temperature changes in layers with cement addition and layers with cement and fly ash addition were observed to be similar to 15 degrees C. As a result, the use of cement has made the material more resistant to external factors. However, the study also revealed that fly ash could be used instead of cement with a substitute rate of 50% to reduce the cost for long-term storage in terms of industrial applications