جستجوی مقالات مرتبط با کلیدواژه « باطله » در نشریات گروه « مهندسی معدن »

In this research, the separation of solid phase and water in the final tailings of the Zonouz kaolin processing circuit was investigated. The sedimentation of solid particles was investigated by changing different parameters and their effects were evaluated on the initial rate of sedimentation, clarity of clear water, viscosity, and density of the settled pulp. Increasing the pH improved the sedimentation rate, and the settled pulp became denser. Despite the increase in sedimentation rate, the clarity of clear water decreased due to the presence of fine suspended particles at high pH. The use of flocculant, even in a small amount, increased the initial sedimentation rate by six times and improved the clarity of clear water. However, the density of the sedimented part decreased due to the increase in pulp volume.

The prevention of water wastage in mineral processing plants, especially in desert and arid regions is the present and future serious priorities of this industry. To fulfil this goal, Gol-E-Gohar mining and industrial company has defined water recovery projects, including the investigation on the factors affecting the filterability of the tailings of magnetite and hematite processing plants using membrane chamber filter press. In this research, based on the literature review and given the limitations of the process, 10 factors including pH of the pulp, filter aid, flocculent, solid percentage of the pulp, filter medium, time and pressure of squeezing stage, time and pressure of air blowing stage, and finally chamber thickness were selected for investigation of their influence in three steps: initial experiments, one factor tests and designed experiments. It is found the effect of four factors are significant on the "final moisture" of cake including time and pressure of air blowing stage, solid percentage of the pulp and chamber thickness. Also, the major parameters affecting the "throughput" of filtration were defined as the time of air blowing stage, the chamber thickness, the time of squeezing stage, solid percentage of the pulp and interaction effect of the time of air blowing and squeezing stage and the interaction effect of the time of air blowing stage and solid percentage of the pulp. Finally, optimization of the factors based on three objectives was performed, obtaining the minimum moisture content of 14.32 %, the maximum throughput of 0.27 tons per hour per square meter, and a combination of 17% moisture and 0.147 tons per hour per square meter throughput when both moisture and throughput were optimized simultaneously. The optimized conditions were tested and verified in laboratory and pilot scale.

In this research work zinc extraction was investigated using Geocoat process from a low grade zinc concentrate produced from the Kooshk Lead- Zinc accumulated flotation tailings. The sample of tailings contained 3. 64% Zn. About 45% sphalerite was recovered by flotation process and zinc content was upgraded to 11. 97%.. The prepared concentrate was coated on the granite grains of 5-10mm، so experiments were conducted in the small column leaching of 0. 5m height. Solution irrigation was done in the close cycle which took 4 days. Collected liqueur was used for next stage irrigation. Results showed that 81% of sphalerite concentrate was dissolved during 10 cycles (40 days) in which solution، Zn concentration reached to 12. 63g/l/. In the same period 40% of pyrite was dissolved during the process. Making continue bioleaching process until 20th cycle indicated more than 90% Zn extraction. Zn extraction rate is significantly higher than Fe extraction until 40 day. Following the bioleaching process، considerable amount of pyrite was dissolved and Fe concentration increased in the leached solution، however، Zn extraction rate decreased and Zn concentration was improved slightly. Analysis of leaching residuals indicated only 0. 67% Zn content. In comparison of Zn content of low grade concentrate (11. 97%)، 91% Zn was dissolved during bioleaching period. Comparing effect of mixed-mesophile bacteria in the bioleaching column and control test (without addition of bacteria) indicated the Zn recovery improvement of 20-25% in presence of added mixed- bacteria.