Application Study On Dry Magnetic Separation In Volatile Kiln Zinc Slag

Zinc volatile kiln slag is a kind of common solid waste in metallurgical industry. There are many kinds of valuable components in the slag of Shaanxi Zinc Industry Co.,Ltd. Shangluo smelter plant. This dissertation arms to explore a new process of dry magnetic separation, which is clean and efficient for the comprehensive utilization of zinc volatile kiln slag.X-ray diffraction, vibrationg sample magnetometer and reflactive microscope analysis showed that, there are 24.68% of iron, 12.55% coke and 31.8% of quartz in the slag, in which the iron exists as iron oxides, sulfides, and a small amount of pure iron. The coke which adsorbed minerals in their micro apeture, is mainly despersed in the fine slag particles in monomer form, and a small part of the coke is desseminated with the slag. The analysis of the slag before and after grinded shows that, the slag is middle grindable, and they are both in line with the Rosin-Lamler destribution, and magnetic components are enriched in coarse particles, while coke in fine particles.First, a simple dry magnetic separation process is implement to recovery iron only, on which two new processes all-grinding-magnetic- separation and pre-carbonization-grinding-separation are proposed. Electromagnetic separator roller is used in the separation experiments. According to the results, two mathematical models are established, which show the relationship between iron ore grade and recovery with the feed size of the slag, magnetic field strength and deep separation times. Finally, a successful process is achieved, which contains successively pre-carbonization, stage-grinding and stage-separation. Separation results showed that iron owe with 62.0% Fe and coke product with 61.9% C were produced, and 75% Fe in the slag was recovered, and 43% solid waste emission was reduced.A new magnetic separator is designed and manufactured in order to meet the need of industrial production. A method named Sham magnet interval substitution is used to splice and squeeze the fan-shaped magnet into magnetic roller. The magnetic rollers are manufactured in series to make a multi-gradient, multi-roll, permanent magnetic separator named as CG2, which is proved to be successful in the experiments.