FAQs of Magnetic Separation

Introducción: Magnetic separation is an important separation technology in the field of mineral processing and is widely used for the sorting and recovery of various types of ores. Whether it involves ferrous ores such as iron and manganese ores or the extraction of non-ferrous metals such as tungsten and tantalum ores, magnetic separation technology plays a crucial role. This article systematically summarizes the most common questions regarding magnetic separation technology to help you gain a comprehensive understanding of its principles, applications, and equipment selection.

China is one of the earliest countries to understand the magnetic phenomenon. The ancient Chinese discovered that magnets can attract iron but not gold, silver, copper, or other metals. They also discovered the directivity of magnets and produced the earliest compass – Sinan.
La aurora también se forma por la acción de un campo magnético.

1. What is Magnetic Separation?

A method of mineral separation in a non-uniform magnetic field based on the magnetic difference of various minerals.

2. What Are The Applications Of Magnetic Separation?

Separación de minerales ferrosos (hierro, manganeso, cromo, etc.);
Non-Ferrous Metal (tungsten, tantalum, etc.) and rare metals separation;
Separación de minerales no metálicos (amianto, diamante, caolín, etc.);
Extracción de componentes magnéticos de materiales sólidos y residuos.

3. What Is The Magnetic Separation Working Principle?

Bajo la acción de lavado del flujo de agua, las partículas de mineral se sueltan.
In the magnetic field, the magnetic ore particles are aggregated to form a lump of magnetic material, which is attracted to the cylinder. As the cylinder rotates, the non-magnetic mineral, such as gangue, falls off, and the magnetic lump that is finally attracted to the cylinder surface is the concentrate ore. The concentrate goes to the edge of the cylinder, which has the weakest magnetic strength, and is discharged into the concentrate tank under the action of the flushing water. Non-magnetic or weakly magnetic minerals are left in the slurry and finally discharged, which are the tailings.

4. What’s The Precondition of Magnetic Beneficiation?

(1) There must be an uneven magnetic field of sufficient strength and gradient.
(2) There must be a certain magnetic difference between the minerals, that is, the specific susceptibility of the two minerals is different.
(3) For minerals with strong magnetic properties, the magnetic force they receive is greater than the sum of various mechanical forces.

La condición necesaria para la separación de las partículas magnéticas de mineral es que la fuerza magnética de las partículas magnéticas de mineral sea mayor que la fuerza combinada de las fuerzas mecánicas opuestas a ella.

5. Why is Magnetic Separation Only In Non-uniform Magnetic Fields?

En un campo magnético uniforme, el mineral sólo está sometido a torsión, de modo que la dirección de su eje longitudinal es paralela a la dirección del campo magnético.
En un campo magnético no uniforme, las partículas de mineral no sólo se ven afectadas por el par, sino también por la fuerza magnética. Las partículas de mineral giran y se desplazan en la dirección en la que aumenta el gradiente del campo magnético, y finalmente se absorben en la superficie del polo magnético.
De este modo, las partículas magnéticas con diferentes propiedades magnéticas se separan, por lo que la separación magnética sólo puede lograrse en un campo magnético no uniforme.

6. What is The Classification of Magnetic Minerals?

Minerales fuertemente magnéticos: It is easy to pick out in a weak magnetic separator with magnetic field strength H=900~1800Oe.
There are a few such minerals, mainly magnetite, pyrrhotite, titanomagnetite, zinc-iron spar, and the like.
Minerales magnéticos débiles: In the magnetic field strength H = 6000 ~ 2000 Oersted, magnetic beneficiation is somewhat difficult, and some are easy.
Mainly iron-manganese ore, hematite, specularite, limonite, siderite, rhodochrosite, etc.; some titanium, chromium, tungsten-containing minerals; biotite, hornblende, epidote, chlorite, olivine, garnet, pyroxene, etc.;
Minerales no magnéticos: The magnetic separation method is not available currently.
Hay muchos minerales de este tipo, entre ellos:

• Some metal minerals – chalcopyrite, galena, sphalerite, molybdenite, scheelite, cassiterite, gold, etc.
• Most non-metallic minerals – sulfur, coal, graphite, diamond, gypsum, kaolin, etc.
• Most of the rock-forming minerals – quartz, feldspar, calcite, and so on.

7. What is The Purpose of Magnetization Roasting For Weakly Magnetic Iron Ore?

The purpose of magnetization roasting:

• Turn the weak magnetic iron mineral into a ferromagnetic iron mineral;
• Remove gas and crystal water from ore
• Make the ore structure loose, reduce grinding cost
• Improve mineral processing efficiency.

8. How to Change The Surface Magnetism?

(1) Alkali leach magnetization
The NaOH solution leaches the siderite FeCO3, forming Fe(OH)2 on the surface of the ore; the leaching compound is reoxidized to γ-Fe2O3 and Fe3O4.
(2) Hydrophobic
La lixiviación alcalina disocia la superficie del mineral, y el jabón de ácido graso forma una película de hierro de ácido graso hidrófobo con el componente de hierro en el hierro o lodo que permanece en la superficie del mineral, cubriendo la superficie del mineral para aumentar la susceptibilidad magnética.
(3) Magnetic seeds
Ajustar el lodo, añadir semillas magnéticas (como polvo de magnetita finamente molido) y tensioactivo para adherir selectivamente las semillas magnéticas al mineral objetivo con el fin de mejorar las propiedades magnéticas del mineral objetivo y, a continuación, separarlo y reciclarlo con equipos de separación magnética de campo magnético débil.
(4) Magnetization agent
The additional magnetic species is selectively attracted to the target mineral by the magnetizing agent to increase its magnetic properties.

9. What Are The Types of Magnetic Separators?

Since the 1980s, with the advent of bismuth-iron-boron high-magnetic rare-earth permanent magnet materials, the types of magnetic separators have become increasingly diverse. Classification of magnetic separation equipment:

• According to the strength of the magnetic field: weak, medium, and strong.
• According to the media, dry type, wet type separator.
• Según el tipo de campo magnético: constante, giratorio, alterno, pulsante.
• Según la estructura del separador magnético: tipo cilíndrico, tipo cinta, tipo disco, tipo anillo, etc.

Selecting the right magnetic separation equipment is crucial for improving mineral processing efficiency and economic benefits. JXSC Mining Equipment offers a wide range of separadores magnéticos, including wet, dry, high-intensity, and triple-disc models in various specifications to meet different mineral processing needs. If you require professional technical consultation, equipment quotes, or mineral processing plant design services, please feel free to Contacto for assistance.

Whether you want to learn about the principles of magnetic separation technology or need to select the right magnetic separation equipment, our professional technical team can provide comprehensive solutions to help you achieve optimal mineral separation results.