Iron recovery from the waste generated during the cutting of granite

Abstract

Metallic iron is present in the waste left when granite blocks are cut. Thus, the purpose of this study was to characterize this waste using chemical and particle size analyses. To achieve this, X-ray diffraction and scanning electron microscopy coupled with electron back-scattered diffraction were used. To find the method with the best metallic iron recovery from the waste of ornamental rock, three distinct methods were examined: magnetic separation, table concentration and cyclone processing. The first method involved three steps: (1) use of a wet high-intensity magnetic separator, where only the equipment's remaining magnetic field was present; (2) the material from the first step was then submitted to separation again, this time using a magnet for rare earth particles; and (3) this material after two separation processes was finally submitted to ferromagnetic separation. The second method used a concentration table set at various inclinations, oscillation frequencies and wash flow rates. Meanwhile, for the third method, the cyclone tests, only the water pressure was varied. After each test, a chemical analysis was performed to determine the metallic iron present in each sample. The tests revealed that magnetic separation presents the best results. Using this technique, a ferrous concentrate with 93 % metallic iron content and a granite concentrate with only 0.6 % metallic iron were obtained. On the other hand, in the table concentrator tests, the ferrous concentrate only had a metallic concentration of 13.6 %. In separation by the cyclone processing, the product barely contained metallic iron (7.2 % maximum).

Iron recovery from zinc mine tailings by magnetic separation followed by carbothermal reduction of self‐reducing briquettes

“…[15] Besides magnetic separation, the thermal reduction process has been investigated for the purpose of recovering iron from residues in studies about reducing pellets made from electric arc furnace dust using natural gas and the investigation of carbothermal reduction of electric arc furnace dust briquettes in a microwave oven. [16,17] In this type of study, which uses fine raw materials, agglomeration processes to produce pellets, sinter, or briquettes are required to avoid clogs in reactors. Among the studies mentioned, there have not been investigations about selfreducing briquettes made from zinc mine tailings, nor any studies proposing a route that combines physical and thermal processes to obtain metallic iron from those tailings.…”

Characterization of basic oxygen furnace slag and granite waste mixtures to Portland cement production

“…Albite and anorthite, were also detected. Such phases have been detected for several researchers in granite waste composition (Li et al, 2013;Junca et al, 2015). Size analysis showed that BOFS is range of 0.479-2187.76 µm, with 90% lesser than 1258.92 µm, and 50% lesser than 478.63 µm.…”

Influence of Abrasive Blasting and Hot Pressing Preparation on the Pinus taeda Wood Surface

“…These metal particles are widely employed in the automotive and steel industries generating large amounts of wastes with no proper disposal (Nazer et al, 2012). However, the civil industry has been investigating ways to reuse these particulate materials as aggregates for concrete, consequently reducing utilization of natural resources (Junca et al, 2015).…”