Showing 3 results for Mohammadi Soleymani
Moslem Mohammadi Soleymani, Majid Fooladi Mahani, Masoud Rezaeizadeh, Mehdi Bahiraie,
Volume 15, Issue 4 (6-2015)
Abstract
Milling is one of the most important operational stages in processing the minerals. Lifters are usually used with mill liners to extend their life and to enhance the grinding and crushing efficiency. Lifters worn and consequently their dimensions change during the course of operation. These changes in dimensions have a significant influence on the overall economic performance of the mills. Therefore, it is useful to know the relationship between the mill operation and the lifter profile, and the influence of lifter wear on the change in lifter profile. The wear is influenced by a range of parameters such as: media charge level, slurry filling, slurry concentration, and mill speed. In this work, the influences of these operating parameters were investigated using a pilot mill (1000 * 500 mm). To this end, a Copper ore was used to prepare slurry at 40%, 50%, 60%, 70%, and 100% solids concentration by mass. The tests covered a range of slurry filling (U) from 0.5 to 3 with solid charge between 15% and 35% of mill volume and 3 different speeds 65%, 75% and 85% of critical speed. It is found that the mill charge and the mill speed significantly affect the wear rate. For wet condition, increase in the slurry concentration and slurry filling leads to a remarkable decrease in the amount of the wear. By increase in the feed filling (in dry condition) the wear increases too. Wear rate in wet conditions is 2-4 times of dry condition.
M. Mohammadi Soleymani , S. Mirzadeh,
Volume 20, Issue 9 (September 2020)
Abstract
Due to the importance of tumbling mills in processing industries and factories and the lack of an acceptable model for identifying and predicting their performance, it is necessary to optimize these complexes, non-linear, and large systems. This paper aimed to study multi-objective optimization of operating parameters in a tumbling mill. To evaluate the effects of the mill working parameters such as mill speed, ball filling, slurry concentration, and slurry filling on grinding process, power draw, wear of lifters and size distribution of the mill product, it was tried to manufacture a pilot model with a smaller size than the actual mill. For this aim, a mill with 1×0.5m was implemented. The feed of the mill is copper ore with a size smaller than 1 inch. The experiments were done at 65 to 85% of the critical speed. In addition, the combination of the balls was used as grinding media with 10 to 30% of the total volume of the mill. Slurry concentration is 40 to 80% (the weight fraction of solid in slurry) and the slurry filling is between 0.5 and 2.5. In this paper, Adaptive Neuro-Fuzzy Inference System (ANFIS) based multi-objective optimization (NSGA-II) of tumbling mill is done. Level diagrams are used to select the best solution from the Pareto front. The results showed that the best grinding occurs at 70-80% of the critical speed and ball filling of 15-20%. Optimized grinding was observed when the slurry volume is 1-1.5 times of the ball bed voidage volume and the slurry concentration is between 60 and 70%.
Moslem Mohammadi Soleymani, Ehsan Mehrabi Gohari, Samane Khorami,
Volume 24, Issue 8 (August 2024)
Abstract
In this research, two examples of ST-52 steel welding joints were performed by the SMAW welding method using low-hydrogen alkaline electrodes E7018 and E8018. The hardness, tensile strength, and impact toughness of weld were examined and studied at ambient temperature and -29 °C. The hardness test results showed that the highest hardness at the weld metal region belonged to the welding metal E8018. The hardness values for the base metal and the heat-affected area also indicated that the similar weld metal-like behavior is the same in the two samples. The impact test results demonstrated that the mean impact energy of the weld metal E7018 at ambient temperature was higher than E8018. Also, the mean impact energy at -29 °C for the weld metals E8018 and E7018 was equal to 56 J and 73 J, respectively. According to the results, the weld metal E8018 at a temperature of -29 °C shows a more brittle fracture behavior and lower impact toughness than the E7018 weld metal. The results of the weld tensile test revealed that the final weld strength of both filler metals was higher than 546 MPa so that the tensile sample failed from the ST-52 base metal site. According to the Tenth Article of the National Building Regulations of Iran as well as the Seismic Rules of the Regulation AISC 341-10, filler metals E7018 and E8018 meet the requirements of the weld final strength and impact toughness at ambient temperature and -29 °C.
