Excessive iron content in quartz sand raw materials can seriously affect its
application performance in high-end industries such as glass, photovoltaics, and
electronics. Therefore, effective measures must be taken to reduce its iron
impurity content. The following are common methods for dealing with high iron
content in quartz sand raw materials:
1、 Magnetic separation for iron removal
Magnetic separation is the most commonly used method for treating iron
impurities. For weakly magnetic iron minerals in quartz sand, such as hematite,
pseudo hematite, magnetite, etc., high gradient magnetic separators,
electromagnetic dry powder magnetic separators, or wet magnetic separators can
be used for multi-stage magnetic separation. Reasonable configuration of
magnetic separation intensity and equipment quantity can effectively remove
magnetic iron impurities from quartz sand.
2、 Scrubbing and desliming
For some iron inclusions attached to the surface of quartz particles, a
scrubbing machine can be used to vigorously mechanically stir and rub the
material to remove surface mud impurities and iron oxides. Then, fine particle
impurities can be removed through water washing and desliming treatment to
reduce the overall Fe ₂ O3 content.
3、 Acid washing treatment
When iron impurities in quartz sand exist in a chemically bound state,
physical methods are difficult to remove. In this case, acid washing technology
can be used. Common acid solutions include hydrochloric acid, sulfuric acid,
oxalic acid, or composite acids, which dissolve chemical iron impurities in the
acid solution through soaking, stirring, heating, and other methods. After acid
washing, it needs to be thoroughly rinsed to remove residual acid, and the
cleanliness of the sand should be reduced through processes such as dehydration
and drying.
4、 Flotation for impurity removal
For quartz sand with accompanying sulfides or iron minerals, cation reverse
flotation technology can be used for treatment. Add appropriate collectors,
adjust the pH value of the slurry, and flotation iron impurities to improve the
grade of quartz concentrate.
5、 Roasted iron removal
In some cases, iron impurities are tightly bound in quartz particles in a
wrapped state, making it difficult to separate them by conventional physical or
chemical methods. Roasting processes can be used to oxidize or decompose iron
impurities, changing their physical and chemical properties and making them
easier to remove by subsequent magnetic separation or acid washing.
6、 Selected Mineral Sources and Pre treatment
Controlling the iron content of raw materials from the source is the key to
effectively reducing processing pressure. Selecting quartz sand resources with
high ore grade and low iron content in the mining area for primary treatment
such as pre selection, grading, and pre washing can significantly reduce the
cost and process complexity of subsequent iron removal.
In summary, if the iron content of quartz sand raw materials is too high,
targeted treatment can be carried out through magnetic separation, scrubbing,
acid washing, flotation, roasting, and other methods. The appropriate
combination process should be selected according to the form of iron impurities,
particle distribution, and terminal product requirements to achieve the goal of
efficient iron removal and improving product purity.