Quartz fractional sand.
What is quartz sand and where is it used? In this article, we will try to answer the most common questions regarding quartz sand.
Quartz sand is a granular material of mineral origin. Formed as a result of the destruction of quartz-containing rocks. The distribution in the earth’s crust is very wide. The size of the sand fractions varies within the range of 0.1-6 mm. The composition of quartz rocks often contains various impurities in the form of clay carbonates, iron oxides, feldspars and other rocks. They give quartz (naturally transparent or white) different shades. The color range changes from yellow to red-brown and even black. Pure quartz sands have a minimum of inert impurities: up to 99% of the composition is silica. Chemical formula SiO2. The color of quartz sand without impurities is milky.
Types of quartz sand
Quartz sand is divided into two types: material of natural and artificial origin. The first is found in the form of enriched quartz sand of various fractions and is mined mechanically in the developed deposit. The second also has a natural origin: the raw material is crushed vein quartz – a customary rock (pure quartz). For mining, a drilling and blasting method is used, and then the resulting material is crushed for further use.
Quartz sand is classified into several categories based on its origin. River, mountain and burial sand is mined, respectively, on the banks of rivers, in places where rocks emerge and under the soil at a certain depth. The river variety contains a minimum amount of contaminants.
Quartz sand is also divided according to the shape of grains into rounded and crushed. Rounded looks like rounded grains, crushed looks like uneven chopped grains.
Quartz sand mining and production
The extraction of quartz fractional sand is carried out by an open method from a quarry or by a dredger from natural deposits in floodplains of rivers and lakes.
A small amount of impurities and a large amount of quartz – this is the difference between developments in which quartz sand is mined from quarries in which ordinary construction sand is mined. The extracted raw material undergoes a number of technological processes: washing from mud deposits and cleaning from impurities by a chemical method. This process is called beneficiation, it serves to obtain sand of the required quality. As a result, the content of quartz rock increases, and the purest material is obtained, which, after drying in special installations, passes through a series of sieves and is divided into fractions. The resulting products are called fractional quartz sand.
The process of extraction by a dredger is as follows: a mixture of sand and water from the bottom of the reservoir is pumped and transferred through a special pipeline to the storage site. The water is gradually separated from the extracted soil and goes through the drains back into the reservoir. The resulting material is sent to the enterprise for its further enrichment and separation into fractions.
Artificial quartz sand is obtained from vein quartz rock, which is first sent to a crushing plant. There, the raw materials are crushed into grains. This is followed by procedures similar to those when working with quarry sand: the material is washed, dried and separated by a technical sieve into fractions.
Characteristics and properties of quartz sand
Features of quartz sand
The peculiarity of quartz sand, which distinguishes it from other types of sand, is that this material is monomineral, that is, consisting of only one mineral – quartz. This uniformity makes it a valuable industrial raw material. A small proportion of impurities makes it possible to obtain glass with a high degree of transparency from the raw material. Another feature is intergranular porosity. Compared to other materials, quartz sand provides the greatest dirt holding capacity. In addition to this property, there is a low degree of wear of the grains of sand, and quartz sand already performs well as a filtering material.
Chemical properties of quartz sand
The crystalline structure of quartz gives it and the sand obtained from it exceptional characteristics of strength and resistance to the action of alkaline and acidic materials. The very high hardness, refractoriness and chemical composition of quartz sand determine its increased refractoriness and fire safety. The material is dielectric in terms of its properties and is inert to a wide range of chemicals.
Physical properties of quartz sand
All properties of quartz are characteristic of sand:
Bulk density 1300-1500 g / cm3
Abrasion – 0.1
Crushing – 0.3
Hardness (Mohs scale) – 7 (for comparison, the hardness of diamond – 10)
Use for radioactivity – class 1
Abrasion, crushability and hardness of quartz sand are indirect indicators of its strength. To determine the values, the grains are tested on a rotating abrasive metal wheel, the mass of fractions is compressed by a mechanical method and scratched by the grain of the standard and, vice versa, the standard of grain.
Quartz sand fractions:
Dusty – less than 0.1 mm
Fine-grained: 0.1 – 0.8 mm
Medium-grained: 0.8 – 1.6 mm;
Coarse: 1.6 – 6.0 mm
Quartz sand, dusty and fine-grained, is used as part of various building materials, such as building mixtures, putties, grouting, abrasive materials, thin plasters and paints.
Quartz sand of medium grain size is used for filtration and purification of liquids, for sandblasting, for building mixtures, facade and interior plasters, self-leveling floors, concrete solutions, in landscape design, for backfilling of sports grounds.
Material of large fractions is used for the manufacture of paving slabs, concrete blocks, and landscape decoration. It is also used for filtering.
Sand of all fractions is used in the glass, foundry and chemical industries.
Application of quartz sand
For water purification and filtration
The chemical and physical properties of quartz sand make it ideal for use as a water filter. Drinking or technical water, including in swimming pools, can be cleaned with high quality and easily from mechanical impurities and reducing the content of iron, fluorides, chlorides, sulfates, heavy metal salts and other harmful impurities. Excellent adhesive properties help to attract dirt to the surface of sand grains.
Quartz sand for filters is used in the first stage of multi-stage household and industrial filters for mechanical preliminary cleaning. Multiple use is possible, since the material is easily washed out when contaminated by water-air rinsing. The use of a quartz sand filter extends the life of the subsequent filter stages.
One of the most effective surface cleaning techniques is sandblasting. On the surface (glass, metal, stone, wood) to be cleaned, quartz sand or other abrasive is sprayed with a compressed jet of air or water. Grains of sand fly at great speed and destroy the top layer of the surface, cleaning it from scale, corrosion and other coatings. Care must be taken not to damage the stone itself together with the removed layer, such as mold on old masonry.
Quartz sand for sandblasting must be selected taking into account the surface material, the degree of its contamination and further processing.
The main areas of work:
· Cleaning metal from rust and other contaminants;
· Degreasing surfaces;
· Glass matting;
· Cleaning of concrete and masonry;
· Roughening the surface for further processing.
There is a wide variety of abrasives available today, but dry quartz sand remains the most sought after for sandblasting.
Quartz sand for self-leveling floors
Polymer floors filled with quartz sand are durable, seamless, non-slip and hygienic flooring that is easy to clean.
Quartz sand for self-leveling floors is a good way to reduce the cost of traditional self-leveling floors. This material is suitable for both new coatings and existing concrete floors. Most often, polymer floors are used in rooms with significant abrasive loads on the concrete surface. Self-leveling floors in this case are used as a finishing decorative coating. It has a smooth and attractive surface and excellent resistance to stress. Such a floor is characterized by low abrasion, since the polymer in this case acts as a binder, and the main functional load associated with wear is borne by a quartz filler, the abrasion of which is extremely low. To preserve the decorative properties, the floor must be covered with mastic, protective varnish or wax.
Quartz sand in the foundry industry
Molding quartz sand is used in the metallurgical industry for the manufacture of casting molds and cores. The quality of casting in one-off molds is directly related to the characteristics of the foundry sand. The accuracy of the casting, the quality of its surface, the structure and properties of the cast alloys, the likelihood of developing defects and the need for complex finishing operations are highly dependent on the characteristics of the sand. The complex of operations associated with the manufacture of the mold is about 60% of the labor costs for obtaining castings. Molding quartz sands have a homogeneity coefficient of 72 to 80% and are characterized by increased strength and refractoriness.
The glass industry is one of the main consumers of quartz sand.
Glass quartz sand intended for the manufacture of glass must meet special requirements. The proportion of silicon oxide in the material must be at least 95%, clay impurities must be no more than 1%, and iron oxide must be no more than 1%. In high grades, the silicon oxide content reaches 99.8%. The moisture in the dried sand should be no more than 0.5%. The proportion of impurities in the sand directly affects the transparency of the glass made from it.
Quartz sand is the basis for all types of glass. Conventional window, medical, fiberglass, laboratory, electronics and so on are made from one material. Therefore, great attention is paid to the purification of raw materials in the production of quartz sand.
For sports surfaces
When organizing sports grounds with a surface in the form of artificial grass, a backfill of quartz sand in combination with rubber granulate or only quartz sand can be used. On football fields, a composite compound is used: crumb rubber softens friction in the event of a sliding fall of a player. On tennis courts, multifunctional playgrounds, school stadiums and training grounds, only quartz sand is poured between the grass. Excellent drainage properties of sand, provided that the grass is laid on the field correctly, is a guarantee that, even with precipitation, puddles and dirt will not form on the field.
Quartz sand for sports surfaces is environmentally friendly, environmentally neutral and proven to be durable. Thus, the use of quartz sand as an artificial turf substrate gives a particular comfort when playing and training on sports grounds.
For road surfaces
Quartz sand for road surfaces can be used to indicate hazardous areas and special attention. Colored material can be used to highlight road crossings, public transport stops, entrances to industrial facilities or schools. Sharp turns on highways, covered with quartz chips, will reduce the risk of passing through such sections. The increased roughness will increase traction and reduce the risk of uncontrollable skidding.
You can use quartz sand for garden paths and paths, as well as pedestrian areas. Excellent decorative and hygienic properties will allow you to keep walking alleys in proper shape without much effort.
Quartz sand is almost indispensable in a variety of applications and is one of the most important components for home and industry. Technologies with its use have been worked out to perfection. The attractive natural color, as well as the possibility of painting in any shade due to its excellent absorbent properties, expands the usual scope of application. https://ovruch-stone.com.ua/ru/kvarczev%d1%8bj-frakczyonn%d1%8bj-pesok/