4 Stages of the Quartz Sand Beneficiation Process

If you want to know more details about equipment, solutions, etc, please click the button below for free consultation, or leave your requirements!

Chunlei supply professional and honest service.

Quartz sand is an important industrial mineral material, widely used in glass, ceramics, refractory materials, metallurgy, and rubber. The general process of quartz sand beneficiation includes four stages: preparation, preliminary separation, separation, and deep purification.

01

Quartz Sand Preparation 

Back

The main task of pre-selection preparation is to fully dissociate the quartz sand and achieve the appropriate particle size range to prepare for subsequent operations. The main processes include crushing, grinding, and classification.

Crushing: The commonly used crushing equipment includes jaw crushers and impact crushers. Jaw crushers are mainly used for the coarse crushing of quartz, while impact crushers are used for fine crushing operations.

Grinding: The commonly used grinding equipment for quartz sand is a wet rod mill. The fineness of grinding can be controlled, and over-grinding is not easy to occur, which can achieve better results. Moreover, the rod mill also plays a certain role in scrubbing, and removing some impurities.

Classification: The ground products are classified, and the unqualified materials are returned for further grinding, which can effectively control the particle size of the selected materials and provide suitable conditions for separation operations.

02

Quartz Sand Preliminary Separation

Back

The main purpose of preliminary separation of quartz sand is to remove impurities such as ore slurry generated during the grinding process and the oxide iron film on the surface of quartz sand, to avoid their impact on subsequent separation operations and improve separation indicators. The main processes include washing and desliming, and scrubbing.

Washing and desliming: using hydraulic flushing to remove ore slurry and some clay impurities in quartz sand, the main equipment includes drum screens, desliming hoppers, hydraulic cyclones, etc.

Scrubbing: using mechanical external force and mineral friction to remove impurities such as oxide iron film on the surface of quartz sand, and to crush mineral clusters that have not completely dissociated into single particles. Commonly used equipment includes stirring scrubbers, spiral scrubbers, etc.

03

Quartz Sand Separation

Back

Common beneficiation processes for quartz sand include magnetic separation and flotation.

Magnetic separation: Quartz sand is a non-magnetic mineral, but iron-containing minerals such as hematite and brown iron ore are magnetic minerals, which can be removed by magnetic separators. The finer the quartz sand particle size, the better the iron removal effect.

Flotation: This method is commonly used to remove non-magnetic minerals such as mica and feldspar from quartz sand. The flotation of mica and feldspar is generally carried out in an acidic environment, so there is a certain requirement for the corrosion resistance of the equipment.

04

Quartz Sand Deep Purification

Back

When conventional beneficiation methods cannot effectively remove impurities deeply immersed or encapsulated in quartz sand, resulting in low purity of quartz sand, methods such as acid leaching and high-temperature roasting can be used for purification.

Acid leaching: Quartz sand is insoluble in acid, but acid can dissolve other impurities and remove impurities that other methods cannot effectively remove. However, acid leaching requires high operation requirements.

High-temperature roasting: Quartz sand is roasted at high temperature by adding chlorine gas, etc., so that the encapsulated impurities rupture, the impurities are exposed, or the deep impurities undergo reaction and transfer to the mineral surface for removal by other methods.

05

To Wrap Up

Back

The quartz sand beneficiation process consists of these four stages. But in actual application in the mining field, suitable processes and machines should be selected according to the ore properties, mineral composition, and impregnation characteristics of the quartz sand. You can click to knowthe quartz sand processing plant equipment list.

Silicon dioxide (SiO2) is the main chemical component of quartz sand and high purity quartz sand is defined as having a silicon dioxide content of 99.9% or more. As one of the most important industrial raw materials, quartz can be used in industries such as glass, building materials and plastics. The electronics, aerospace, fibre optic communication and military industries have requirements for the purity of silica sand. This article explains the beneficiation method and process flow of high purity quartz sand.

1.High purity quartz sand beneficiation methods

In industrial production, the purification methods of high purity quartz sand mainly contain physical purification, chemical purification and biological purification.

1.1 Physical purification of high purity quartz sand

Common physical refining methods for high purity quartz include water washing - graded desliming, scrubbing, gravity separation, magnetic separation and flotation, one or a combination of these forms can be used to remove impure minerals from silica sand and achieve refining requirements.

Featured content:
10 Questions You Should Know about Hydraulic Underground Core Drilling Equipment

The company is the world’s best quartz sand beneficiation equipment supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Water washing - Classified desliming/scrubbing

In quartz sand beneficiation, particles below 0.1mm are generally referred to as mineral sludge because the finer the particle size, the lower the silica content and the greater the relative impurity mineral content. The impurity minerals are removed by water washing or scrubbing to improve the concentrate grade.

Gravity separation

Gravity separation mainly uses the difference in density, size and shape of the mineral particles to produce different directions of movement and distribution speeds under the action of water and centrifugal force, thus achieving separation.

Magnetic separation

Magnetic separation is the removal of magnetic minerals such as haematite, brown iron and black mica from minerals by means of magnetic separation equipment, using the magnetic differences between quartz and impurity minerals.

Flotation

Flotation is the use of chemicals and equipment to change the nature of the mineral surface to remove a range of impurities present in the mineral under acidic conditions, separating out high purity quartz sand.

1.2 Chemical purification of high purity quartz sand

Among the chemical purification methods for high purity quartz sand, acid leaching and alkali leaching methods are more effective for the purification of high purity quartz sand.

Acid leaching

The acids commonly used for acid leaching are mainly sulphuric acid, hydrochloric acid, nitric acid, etc. When the acid concentration is low, it is better to remove impurities such as iron, aluminium and magnesium; when the acid is thicker, it is better to remove impurities such as titanium and chromium.

Alkaline leaching

Alkaline leaching is the use of alkaline solutions, usually sodium hydroxide or sodium carbonate solutions to dissolve aluminosilicate impurities, for the purification of quartz sand.

1.3 Biopurification of high purity quartz sand

The biological purification method of high purity quartz sand is mainly through microbial leaching purification, which is achieved through the physiological properties of microorganisms and their metabolites, after oxidation, dissolution and decomposition.

2. High purity quartz sand process flow

In the beneficiation process, the process flow of high purity quartz sand mainly contains the following links:

2.1 Quartz sand crushing

Generally two-stage crushing process is adopted, firstly coarse crushing by jaw crusher, after crushing, the crushed material is conveyed by belt conveyor to vibrating screen for screening, the unqualified material is sent to cone crusher for fine crushing, the qualified material is conveyed to powder bin.

2.2 Grinding and classification

The main purpose of the grinding process is to grind the raw ore to a certain size and to dissociate the quartz sand from the vein minerals. The classifying equipment cooperates with the grinding equipment to produce quartz sand materials with qualified particle size.

2.3 Magnetic separation

The magnetic separation process uses a wet magnetic separator for primary separation, which is used to remove hematite, limonite, ilmenite and their congeners particles present in the quartz sand.

2.4 Flotation

Flotation removes mica and iron oxide from quartz. The flotation operation is carried out using sulphuric acid as an adjusting agent, sodium petroleum sulphonate as a trapping agent and pine alcohol oil as a foaming agent.

2.5 Acid leaching

After two separations by magnetic separation and flotation, impurities are still present in the quartz in the form of flecks or inclusions. To remove this impurity, acid leaching is required, using a mixture of different acids to remove the different impurities.

2.6 Washing

Soluble impurity residues adhere to the surface of the quartz sand after acid leaching and need to be removed by washing. The washing of the acid-impregnated minerals causes the impurities and residues on the quartz surface to diffuse into the solution, thus completing the cleaning process.

The above mainly describes the beneficiation method and process flow of high purity quartz sand. When building a beneficiation plant, in order to obtain high purity quartz sand, the appropriate beneficiation process should be selected according to the nature of the ore, therefore, it is recommended to tailor the appropriate process solution to obtain high purity quartz sand through beneficiation test analysis.

More details about Mine Beneficiation

Check it out!

Join groups to know more typical cases: 

Are you interested in learning more about jaw rock crusher? Contact us today to secure an expert consultation!