Scientific Mining Journal

ABSTRACT

The Turkish cement sector aims to contribute to sustainability by considering economic, social and environmental conditions and by using technological facilities. It is very difficult to create a sustainable economic development in an environment where resources are becoming more and more diminishing and expensive, while preserving environmental resources. In the cement sector, where energy and raw materials are used heavily, replacing fossil fuels and natural raw materials with alternatives has become one of the most important issues in the cement sector in recent times. In this process; primary fossil fuels such as coal, petroleum coke, lignite and natural raw materials such as limestone, marl and clay have been used extensively to solve the problem of sustainable raw materials in mining and to accelerate the search for alternative and new raw materials. For this purpose, as an alternative to cement clay, the use of mudstone as a raw material in the cement industry has been investigated.

ABSTRACT

Screening is one of the most widely used unit operations in mineral processing plants. The use of Discrete Element Modelling (DEM) for the modelling and simulation of granular material in the area of mineral processing started to widespread since 1990s. DEM, which has been successfully used in modelling of many unit operations (grinding, storage, material handling, magnetic separation, etc.), provides significant contributions to the studies for the quantification of the effects of various design and operating conditions and optimization of operations. Nevertheless, in Turkey, only a small number of studies are encountered where this method is utilized.

In this study, screening operation is modelled using DEM. By this means, the effects of various design and operating variables on the screening efficiency and on the product characteristics were investigated. Additionally, by conducting screening tests on a pilot scale industrial screen, the predicting capability of the simulator was verified by comparing the data obtained from the simulations with the pilot scale tests at the same conditions. The results show that the simulation results present very good agreement with the pilot-scale test results.

 ABSTRACT

ABSTRACT

The most common industrial method used in extraction of gold from ores is cyanide leaching. Dissolution of minerals (copper, zinc etc.) present in the ore during cyanide leaching results in an increase in cyanide consumption and adversely affects the extraction of gold. Dissolved metals also lead to technical problems in solution purification and metal recovery stage. An effluent (solution/pulp) containing free and metal-cyanide species is produced after cyanide leaching. This effluent should be treated through chemical destruction (e.g., INCO SO2/Air, H2O2) or cyanide recovery processes to decrease its cyanide content down to regulatory limits (i.e., CN WAD<10 mg/L). Recovery of cyanide allows a decrease of the concentration of cyanide level to required levels as well as the reagent costs. Various processes e.g. activated carbon adsorption, ion exchange (IX), solvent extraction (SX), electro-winning, acidification-absorption based processes (AVR, Cyanisorb), SART etc. have been developed for recovery of cyanide. Consumption of cyanide can be reduced by 50-75% by implementation of industrially applied cyanide recovery techniques (e.g., AVR, SART). However, during the application of these processes in plants, various problems have been faced. Therefore, new and more effective methods need to be developed. In this study, technical features and advantages/disadvantages of cyanide recovery methods/processes were discussed in detail.