4 Processes for Removing Iron from Quartz Sand

Quartz Sand is an important industrial mineral raw material and has been widely used in glass, metallurgy, aviation, electronics, machinery, refractory materials and other industries.

However, different industries have different requirements for the purity of quartz sand. Too many impurities will affect the value of quartz sand. Among many impurities, iron is the most harmful impurity.

At present, the common methods of iron removal from quartz sand include mechanical scrubbing, flotation, magnetic separation and acid leaching.

Quartz Sand Mechanical Scrubbing Method for Iron Removal

The mechanical scrubbing method is to remove the iron oxide film and other iron-containing minerals on the surface of quartz particles by means of mechanical external force and friction and collision between minerals.

There are two main ways of scrubbing, namely the scrubbing machine scrubbing method and the rod grinding scrubbing method.

The scrubbing method is to remove iron impurities by stirring and scrubbing with the help of a scrubbing machine. Commonly used equipment are spiral chute scrubbers and agitator scrubbers. This method has higher requirements on the wear resistance of the equipment.

The rod grinding scrubbing method is to use a rod mill to do strong scrubbing with chemicals, and the effect is better than that of a scrubbing machine. It can not only remove surface impurities, but also remove impurities in uneven places and small gaps.

The mechanical scrubbing method is the most widely used quartz sand iron removal process at present, with low cost, good effect and simple operation.

Quartz Sand Flotation for Iron Removal

The flotation method mainly uses chemicals to inhibit quartz, and flotation of iron-bearing minerals in quartz sand with collectors.

According to the difference of the medicament, it can be divided into three types: the first is the fluorine and acid method. This method is simple to operate, has good effect and stable indicators, but the disadvantage is that the pollution is serious and the ecology is destroyed;

The second is the fluorine-free and acid method. Compared with the first method, this process greatly reduces the damage to the ecology. However, the strong acid environment has higher requirements on the corrosion resistance of flotation equipment;

The third is the fluorine-free and acid-free method. This method has high technical requirements and complicated process, and is rarely used at present.

Quartz Sand Magnetic Separation for Iron Removal

Quartz sand is a non-magnetic mineral, while iron impurities are magnetic minerals. Using this difference, iron impurities can be well removed.

Strong magnetic minerals mainly magnetite can be removed by weak magnetic separator.

Weak magnetic minerals such as hematite and limonite can be removed with a strong magnetic separator.

Magnetic separation is also divided into wet magnetic separation and dry magnetic separation, and different methods can be selected according to different situations.

The magnetic separation method has a good effect on the iron-containing impurities dispersed in the quartz sand, but it is not ideal for the iron oxide film on the mineral surface.

Quartz Sand Acid Leaching for Iron Removal

Quartz sand is insoluble in acid (except hydrofluoric acid), but acid can dissolve other minerals, so acid leaching can be adopted to remove impurities.

Acid leaching can not only remove iron-containing impurities, but also non-metallic impurities.

Acid leaching can be divided into single acid leaching and mixed acid leaching.

The single acid leaching method has a good effect on the relatively simple impurity composition, but the mixed acid leaching method is better for the complex impurity composition.

In addition to the above-mentioned processes for iron removal from quartz sand, there are ultrasonic iron removal methods, microbial iron removal methods, etc.

In actual production, the best quartz sand iron removal process can be selected according to the mineral composition, environmental benefits, economic benefits and other aspects.