Magnetic Separation of Impurities from Hydrometallurgy Solutions and Waste Water Using Magnetic Iron Ore Seeding

Abstract

The removal of iron ion from leaching solution is critical for the recovery of value metals, with the method of choice commonly being crystallization (precipitation). This paper summarized the new improvements in iron removal by precipitation methods in recent years and proposed a novel process, magnetic seeding and separation. The new process can promote iron precipitate aggregation and growth on the surface of the magnetic iron ore seeds. A core-shell structure was formed of iron precipitate and magnetic iron ore seeds, which can be magnetized and coalesced in magnetic field, accelerating the solid-liquid separation. The efficient magnetic flocculation and separation offset the poor settleability and filterability of the residues, contributing to the development of the hydrometallurgy process. Moreover, magnetic seeding and separation was also used for the removal of organic and inorganic contaminants from wastewater, significantly improving the purification efficiency. Therefore, iron ore not only played an important role in mining and steel manufacture, but also can be used to solve some problems in crossing fields.

Tailored synthesis of iron oxide nanoparticles for specific applications using a statistical experimental design

“…The magnetic properties of the nanoparticles decrease as pH increases above 9. Thus, it is evident that pH plays a critical role in the formation pathway, rather than a specific ammonia dilution (molar ratio between ammonia and iron ions) as stated in a recent paper [ 3 ].

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“…It should be noted that even the manipulation of the synthesis parameters for the specific obtention of goethite could be particularly useful in some applications taking advantage of its shape [ 3 ].…”

“…Magnetic nanoparticles (MNP) are versatile materials that have practical uses in fields like magnetic recording, drug delivery, bioimaging, hyperthermia, photothermal therapy, sensors, water purification, and magnetic separation [ [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] ]. Different kinds of iron oxide nanoparticles are promising, with Fe 3 O 4 and γ-Fe 2 O 3 being the most extensively explored [ 12 ].…”