Separation of quartz sand and metal minerals

Common gangue minerals in quartz sand include hematite, magnetite, limonite, ilmenite and other metallic minerals, as well as non-metallic minerals mainly feldspar.

The metal minerals in quartz sand are mainly iron-containing minerals, which exist in the following forms in quartz sand:

Found in clays or kaolinized feldspars;

Attaches to the surface of quartz particles to form an iron hydroxide film;

Found in heavy mineral impurities such as ilmenite;

Exists in quartz grains in the form of dissipation or penetration;

Exists in mica, hornblende and other mineral particles.

Since iron impurities exist in more complex forms, their separation processes are also more diverse, mainly including the following five types:

Scrub Method

The scrubbing method uses mechanical force and friction between mineral particles to remove thin film iron and adhesive impurities on the surface of quartz sand. It can also remove part of the iron minerals in clay feldspar. In this method, factors that have a greater impact on the scrubbing effect include the structural characteristics and configuration of the scrubbing machine itself, scrubbing time, scrubbing concentration, etc. The selection of scrubbing equipment should be determined after testing based on the properties of quartz sand ore. The scrubbing concentration is generally controlled at 50% to 60%, and the scrubbing time is subject to initially meeting product quality requirements. The specifics should be determined based on tests.

Magnetic Separation

Magnetic separation is mainly used to remove magnetic minerals such as hematite, limonite, magnetite, and biotite. When the iron impurities in quartz sand are low, a wet strong magnetic separator is generally used for separation. The more important influencing factor is the fineness of the selected minerals. Generally, the finer the quartz sand ore particles, the better the effect of separating iron impurities.

Reselection

The gravity separation method can remove heavy minerals in quartz sand, mainly ilmenite, whose density is greater than 2.9g/cm3. Spiral chute is often used as quartz sand gravity separation equipment.

Flotation

The flotation method can be divided into two processes: separate flotation of iron and mica and combined flotation of iron and mica. The chemical systems used in these two methods are different. Petroleum sulfonate and pine oil are mainly used to flotate iron. , using sulfuric acid as a pulp conditioner.

Microbial Leaching

In addition to the above three conventional mineral processing methods, microbial leaching is also a method that can remove thin film iron on the surface of quartz. It mainly uses Aspergillus niger, Penicillium, and other microorganisms to soak it, but this technology has not yet been applied on a large scale. in industrial production.