Trash minerals in common quartz sand vary by geographic location and deposit characteristics, but the following are some common trash minerals that may be present in quartz sand:
Goto Chunlei to know more.
Feldspar: Feldspar is a kind of aluminum-containing mineral, and the common ones are albite and potassium feldspar. They are usually white, pink, or gray. Feldspar is a common impurity in quartz sand, which can affect the purity and transparency of quartz sand.
Mica: Mica is a flaky mineral; the common ones are muscovite and biotite. They may exist in the quartz sand as fine flake particles, affecting the texture and transparency of the sand body.
Iron oxide minerals: Such as hematite and magnetite, give quartz sand a different color, which may affect its use in areas such as glass manufacturing.
Clay Minerals: Quartz sand may contain clay particles that can affect the fluidity and processing properties of the sand body.
Carbonate minerals: Such as calcite or dolomite, usually exist in the form of fine particles. These minerals' presence may affect the quartz sand's chemical stability.
Other metal oxides: Such as zircon (zircon) and so on. These minerals can affect the chemical composition of the quartz sand.
Organic matter: Organic matter residues may also be present in quartz sand, mainly if formed in a natural environment.
The zero electric point of impurity minerals in quartz sand refers to the pH value in solution when the mineral surface has a specific charge, that is, the pH value at which the surface charge is neutralized. At this pH value, the charge on the mineral surface will become neutral, affecting the interaction between the mineral and other substances, such as adsorption, precipitation, etc.
The following are the zero-electric point ranges of impurity minerals in some typical quartz sands. Note that these values may vary due to deposit origin, experimental conditions, etc.
The zero charge point of mica is in the pH 2-4 range.
Hematite has a zero charge point around pH 9, and magnetite has a zero charge point in the pH 6-7 range.
Calcite has a zero charge point between pH 8-9, and dolomite has a zero charge point in the pH 9-10 range.
Zircon has a zero charge point around pH 6-7.
Mineral Name
Zero Point (PZC)
Potassium feldspar K(AISi3O8)
1.4-1.7
Albite NA(AISi3O8), Anorthite Ca(AI2Si2O8)
1.9-3.6
Muscovite KAI2[Si3AIO10] (OH, F)2
1.0
Quartz SiO2
2.0
Apatite Ca5(PO4)3(OH,F,CI)
4.0-7.0
Magnet Mine Fe3O4
6.3-6.7
Hematite Fe2O3
5.2-8.7
Ilmenite FeTiO3
5.6
Goethite FeOOH
5.9-6.9
These zero electric point values are approximate and can be determined by measuring properties such as charge in a laboratory setting. Knowing the point of zero electricity of impurity minerals can help optimize the beneficiation and processing of quartz sand for more efficient separation and purification. In different industrial applications, this information also helps predict and control impurities' behavior to obtain quartz sand products of desired purity.
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
If you want to learn more, please visit our website quartz sand beneficiation equipment.
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.
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:
If you are looking for more details, kindly visit crushing equipment.