Conventional pretreatment in quartz sand iron removal process

High-purity quartz is usually purified from minerals with high SiO2 content. Quartz is widely distributed in nature, but unprocessed natural quartz cannot easily meet the quality requirements of high-purity quartz. High-purity quartz is actually a quartz sand product with high purity SiO 2 obtained from quartz raw ore through a relatively complex purification process. .

The types and contents of trace elements in quartz lattices formed under different geological backgrounds vary greatly. Trace element diversity can play a key role in indicating diagenesis. Due to mineralization factors and other reasons, the main components of quartz ore are SiO 2 and a small amount of aluminum, iron, magnesium, calcium, sodium, potassium, etc. The aluminum-containing impure minerals in quartz ore are mainly clay minerals, such as feldspar, mica, kaolin, etc., while the iron-containing impure minerals are mainly hematite and goethite.

Physical and chemical methods are used to treat iron impurities in quartz. Most physical methods are based on pretreatment, with the purpose of relatively easily removing some iron impurities, including exposed iron films and impurity mineral phases on the particle surface, in preparation for further purification.

Chemical methods such as acid leaching and complexation can further remove iron impurities that are difficult to eliminate. Physical and chemical methods play different roles in the impurity removal process of quartz minerals, so a combination of physical and chemical methods will be more likely to remove iron impurities.

Physical impurity removal methods include scrubbing, magnetic separation, gravity separation, etc.

Commonly used methods for pre-concentration operations include crushing, grinding, grading, optical separation, scrubbing, pickling, etc. The crushing and grinding process requires crushing the material to the required particle size range, releasing impurities and inclusions in the quartz as selectively as possible, and minimizing the damage to the quartz caused by the friction between the grinding media and the quartz during the crushing and grinding process. pollute. When ceramic or alumina media are used for ball milling or stone grinding, the amount of debris produced in the grinding media is smaller than that of iron media, but the contaminants produced are more difficult to remove than iron contaminants.

Photoelectric color selection can be used to separate colored quartz. Different color variations in quartz often indicate the presence of large amounts of certain impure elements. Since impurities in quartz crystals are difficult to remove, separating these particles through photoelectric color selection can improve the quality of high-purity quartz products. Optical sorting can also separate some colored impurity minerals, such as rutile, biotite, etc. Currently, quartz grain size options are limited to the 5-30 mm range. If fine-grained quartz can be sorted, it will be an economical and efficient new sorting technology. Separating these particles through photoelectric color selection can improve the quality of high-purity quartz products.

Optical sorting can also separate some colored impurity minerals, such as rutile, biotite, etc. Currently, quartz grain size options are limited to the 5-30 mm range. If fine-grained quartz can be sorted, it will be an economical and efficient new sorting technology. Separating these particles through photoelectric color selection can improve the quality of high-purity quartz products. Optical sorting can also separate some colored impurity minerals, such as rutile, biotite, etc. Currently, quartz grain size options are limited to the 5-30 mm range. If fine-grained quartz can be sorted, it will be an economical and efficient new sorting technology.

Scrubbing is a mineral processing method that removes impurities attached to the mineral surface through mechanical force and abrasive force between mineral particles. Friction scrubbing has been used as a physical decontamination treatment in many areas of mineral purification, particularly in removing clay impurities from the surface of target minerals. It can crush mineral aggregates that have not yet formed into monomers and achieve further purification through classification operations. At present, the main methods include rod friction cleaning, mechanical scrubbing, ultrasonic scrubbing, etc.

Quartz scrubbing removes the iron oxide film on the surface of quartz particles and the iron-containing minerals attached to the quartz particles through the collision and friction between the equipment and the mineral particles and between the mineral particles. The structural configuration, strength, scrubbing time, slurry concentration, added chemical media, etc. of the scrubbing machine all have a certain impact on the scrubbing effect. Slurry concentration affects the dispersion and friction between particles, and it is necessary to determine the optimized final slurry concentration while only changing the slurry concentration.