Quantity | 12000 - 50000 |
Price | USD |
MOQ | 1 set |
Port | Qingdao port, China |
Packaging | Nude packing with parts packed in wood case. |
Lead Time | 20 |
High-purity quartz sand generally refers to quartz powder with SiO 2 content higher than 99.9%, which is mainly used in IC integrated circuits and quartz glass industries. Its high-grade products are more widely used in large-scale and ultra-large-scale integrated circuits, optical fibers, lasers, aerospace, military. High purity quartz sand is a neutral inorganic filler, which does not contain crystalline water and does not participate in the chemical reaction of the filler. It is a very stable mineral filler. It is widely used in plastics, rubber, ceramics and coatings. It can not only increase the new functions of products, but also save a lot of raw materials.
Purification of quartz sand:
Purification of quartz sand is a highly difficult separation
technology to obtain refined quartz sand or high purity quartz
sand (such as electronic products) by removing small or trace
impurities from quartz sand. In recent years, the main
technological process for producing high purity quartz sand in
China is as follows: raw silica is washed out by washing machine,
crusher is roughly broken, qualified quartz material is put into
roasting furnace, roasted at 850-980 (?) for 6 hours, after
roasting, quartz material is dragged into clean water for water
quenching, and impurities are removed by manual sorting. After
magnetic separation, quartz sand is put into an acid cylinder
equipped with HCl and HF mixed acid for one week. Then high
purity quartz sand is prepared by flotation, dehydration, baking,
cooling and packaging.
Main process and technical requirements of quartz sand
purification:
1. Coarse dressing: remove the obvious impurities and foreign
substances in all kinds of quartz raw ores; 2. Crush: use
professional crusher to crush quartz raw ores to particles with a
diameter of 1-20mm; 3. Water quenching: put burned quartz
particles in cold water for rapid cooling in order to remove
bubbles, water marks and some wrapped impurities in minerals. The
purpose of quality is to crack minerals. Water quenching
treatment of quartz calcination, also known as thermal
fragmentation, refers to the crystalline transformation of quartz
(alpha quartz beta quartz beta squamous quartz) occurring during
calcination at high temperature, so that the volume of quartz
increases, and the original defect degree in the crystal becomes
more serious. When water quenching, the volume of the crystal
suddenly decreases, and the internal stress at the defect
increases rapidly, which promotes the crystal. A method of
breaking a body at a defect. The crystal breaks at the defect,
which exposes the inclusions and impurities in the cracks in the
original quartz to the surface of the particles, and can be
easily removed by acid treatment.
4. Crushing: Ultrafine quartz sand with particle size of 5-50
um is prepared by wet or dry grinding; 5. Magnetic separation:
high-gradient magnetic separation equipment with magnetic field
strength of 50-15 000 Gauss is selected to remove magnetic
minerals in the ore, such as limonite, hematite, mica, garnet,
pyrite, ilmenite, etc.
Generally, at least two stages of magnetic separation are
arranged in the process. The main purpose of one stage magnetic
separation is to remove the strong magnetic substances in the ore
and avoid adverse effects on the follow-up work. The second stage
of magnetic separation is mainly to remove weak and very weak
magnetic minerals from the ore. A section of magnetic separation
generally uses permanent magnet high magnetic cylinder magnetic
separator, magnetic field generally 6000-8000 Gauss. The second
stage of magnetic separation generally uses permanent magnet high
gradient magnetic separator or electromagnetic induction magnetic
separator. The former is more acceptable than the latter because
of its low energy consumption, light weight, higher magnetic
gradient and relatively low investment.
Some people think that it is the function of reducing iron, but
in fact it is not. Practice has proved that magnetic separation
can reduce the content of impurities such as aluminium, potassium
and sodium to a certain extent, and some impurities that can be
removed by magnetic separation can not be removed by acid
pickling and flotation. Magnetic separation is an indispensable
and important process in the preparation of high purity
quartz.
6. Classification: Classification equipment is used to divide
raw materials into many kinds of granularity range products
according to the standard, and in the subsequent treatment,
according to the granularity range, the classification equipment
can be divided into screening machine and airflow classification
equipment. It can be selected according to the requirement of
output and grain size range.
7. Roasting: Quartz raw ore particles are roasted for 2-5 hours
in a professional roaster at 300-1500 C. Chlorination roasting is
the main method for removing quartz lattice impurities. There are
great differences in the action mode and effect between different
chlorinating agents and lattice impurities. (Specific effects can
be linked to the minor edition, which can provide more detailed
information.) 8. Water crushing: The burned quartz particles are
quickly cooled in hot water at room temperature to dissolve the
soluble substances produced by roasting, and then heated for
0.5-2 hours to increase the solubility of the soluble substances
in water.
9. Flotation: The impurities with specific gravity less than 1
are removed by adding flotation agent to the water-crushed fine
quartz sand powder. It mainly removes non-magnetic impurities,
such as feldspar, pure muscovite and so on.
10. Deionized water washing: wash the residual flotation agent
and the impurities on the surface of quartz sand with deionized
water; 11. Drying: first air-drying (drying) the quartz sand
washed with deionized water to remove large quantities of water,
and then drying it in special drying equipment, and heating it to
100-200 degrees C; 12. acid leaching: after drying. When quartz
sand is added to the impregnating tank, acid (sulphuric acid,
hydrochloric acid or hydrofluoric acid) used for acid leaching is
added rapidly under the condition of drying and high temperature.
The concentration of acid is 5%-20%. Under the condition of
30-100 C, it is stirred at constant temperature for 2-24 hours to
remove trace metal and non-metallic impurities in fine powder of
quartz sand; acid leaching is the purification process of high
purity quartz sand. One of the most important processes is to
prepare quartz glass for light source or quartz material for
photovoltaic and semiconductor devices. The main purpose of acid
leaching is to remove acid-soluble metal oxides and some silicate
minerals as well as trace impurities such as soluble aluminium
and iron in ores. After roasting, water quenching, sorting and
high intensity magnetic separation, most of the oxide and
impurity minerals have been removed, but there are still some
oxide and impurity minerals in grain boundaries, micro-cracks and
crystals, which are difficult to remove. Therefore, long-term
acid leaching is used to remove such
impurities.
Of course, in order to achieve the goal, the process may be
adjusted according to the situation of the original ore, such as
two-stage pickling and pre-acid leaching. In a word, in order to
produce high-purity quartz, the means can be used as far as
possible and the methods can be thought of as far as possible. In
some processes, ultrasonic wave and other processes will be added
to guarantee the pickling effect.
13. Deionized washing: The raw materials after acid leaching are
washed with deionized water to remove the acid liquor contained
in the raw materials until they are neutral; 14. Drying and
packaging: drying the raw materials with special drying
equipment, and vacuum packaging in the purification workshop to
obtain the products.