Quartz sand - classification and performance properties. Quartz sand: applications and production Quartz sand purpose

Quartz sand is natural material with a high content of silicon oxide, mined by crushing a quartz vein, or from open pits and rivers or in a closed way.

Unlike conventional sand, this material is characterized by monomineralism, high sorption properties, low content of impurities and metals. In addition, quartz sand is resistant to any environmental influences.

Where is quartz sand used?

There are a lot of uses for quartz sand, but we will look at the main industries and find out where quartz sand is used:
- the water industry is water canals, pools, reservoirs, everything that is connected with water purification, water treatment. Wherever there is a need for water purification and filters are used, there is a need for quartz sand;
- sandblasting of surfaces - absolutely any material is sandblasted with quartz sand, both for protection against corrosion and cleansing from mud deposits, and for decorative purposes;
- glass industry - glass production is impossible without our material;
- the foundry industry cannot do without molding sand;
- construction of sports facilities - playgrounds, football fields, tennis courts and so on, all built using quartz material;
- Oil and gas industry;
- production of dry building mixtures;
- decorative interiors, designs;
- production of quartz plates;
- railway industry and so on….

What is quartz sand made of?

Quartz sand consists mainly of silicon oxide, quartz has a crystalline structure, and the sand obtained from it is highly resistant to alkalis and acids. It is inert to most elements periodic system Mendeleev.

What is the difference between quartz sand and ordinary sand?

As mentioned above, ordinary sand is not quartz due to the low content of quartz in its composition. There are many in ordinary sand various elements, ranging from clay to metals, and quartz sand is characterized by a predominantly high content of quartz, reaching up to 99% of the total mass.

Where is quartz sand mined?

Quartz sand is mined in quarries open way, i.e. I just dig earthen soil with excavators and develop deposits of quartz sand. It is also mined in a closed way from reservoirs, using a powerful pump installed on a floating mobile platform. The pump under pressure sucks in water with sand, turning them into dumps, the water goes back into the reservoir, and the sand remains on the dumps. And another way is crushing a quartz vein, a rock that is blown up, crushed in special crushers to the desired size.

What miracles are not prepared on Earth for man! Here, for example, is an amazing sight - white sand. From afar, you won’t understand right away: is it snowdrifts in the middle of summer, or mountains, or maybe table salt or another chemical? And only approaching, taking it in the palm of your hand and waking up through your fingers, you understand that this is white sand, the photo of which is given in this article. And it consists of quartz - a mineral common on Earth. Quartz is included in the mineral composition of oligomictic and polymictic sands that make up the dunes of deserts, dunes of sea coasts, and shoals of water bodies.

Natural sand white

Deposits are found in river valleys. White river sand is the purest, it usually does not contain pollutants, as well as mountain quartz sand, weathered vein outcrops. It is quite possible to meet nuggets in deposits of natural quartz sand precious metals or their minerals. There is white sand buried under layers of other sedimentary rocks and mined in a quarry. It usually contains pollutants in the form of an admixture of clays, sandy loams, loams, polymictic sands, which are found in the thickness of quartz sands in the form of interlayers and lenses.

Creation of nature and human hands

White sand, consisting of 90-95% of quartz, is not so common and is very much appreciated as a raw material for many. The lack of natural sand can be filled - artificial quartz sand can be obtained using crushing and screening equipment. For the production of sand, monolithic blocks of milky-white quartz are used, crushing which and sifting the destroyed rock, sand is obtained with certain and desired sizes (fractions) of particles. Artificial sand differs from natural sand in exceptional monomineralism, sharp-angled grains of sand.

Where is quartz sand used?

White sand is used to make glass. The following requirements are imposed on it: 95% of it consists of quartz, it must be medium-grained (diameter of sand grains is 0.25-0.5 mm), without admixture of substances that are sparingly soluble in the glass mass, without harmful impurities of minerals containing iron, chromium, titanium (they color the glass and increase its light absorption). Good glass sand is considered to be one that is 98.5% quartz and includes no more than 0.1% iron oxide.

It is necessary for the manufacture of chemical glassware, in instrumentation - it can withstand significant temperature changes. For molds and cores in the foundry of ferrous and non-ferrous metals, quartz sand is also used, which is called molding sand in metallurgy. The quality of this sand is determined by its shape and the shape of the particles that affect the gas permeability, and the amount of impurities that reduce the refractoriness of the sands. It is necessary that the sands do not contain minerals with a high content of sulfur and phosphorus, which are harmful to metal casting. Quartz sand is used for production and "sandpaper" - for this sand is melted with graphite and carborundum is obtained, second only to diamond in hardness. The exceptional dirt-holding capacity (sorption capacity) of quartz sand is used in filters for water purification from iron and manganese oxides. This sand is used in construction for plastering surfaces and for the production of finishing panels. landscape design. And even coffee warmed up in a food warmer filled with white quartz sand will delight you with its fragrant taste.

Quartz sand is a type of foundry sand. This is crushed quartz, which is used in various fields. It is mined different ways. In our article, you can see a photo of quartz sand in order to further understand what it is actually about.

Classification

Quartz sand is divided into:

• river (is the cleanest and most expensive);
• marine (particles are mixed with clay and silt elements. Demand for it is less than for river);
• soil (cellar, located under a layer of clay, soil. It is characterized by an acute-angled shape and roughness. It is used in construction works Oh);
• ravine (has impurities of silt. These are rough fractions of an acute-angled shape. They are part of the solutions of plaster, concrete);
• mountainous (the origin is located in a mountainous area. According to its characteristics, it is close to a ravine).

Quartz sand is divided into natural and artificial. In the first case, rounded, natural sand appears as a result of the action of water and air. Quartz grains become smooth and round.

In the second case, a quartz vein is crushed, obtaining crushed sand. The rock is blown up, obtaining acute-angled elements, which are divided into fractions. Artificial sand is monomineral.

Its advantages include the following:

• Silicon oxide IV is 98%.
• Contains no organic impurities.
• Resistant to mechanical and chemical influences.
• High temperatures withstand easily.

Application

This inorganic mineral has a number of properties that make it a unique material. Quartz sand:

• does not react with other chemicals;
• has a high bulk density;
• durable (grains are almost not subject to abrasion);
• radiation safe;
• is a good sorbent;
• may be stained.

Due to its characteristics, the mineral has become necessary material in many areas. How is quartz sand used? It is used in:

• light and heavy industry (fractionated sand is filled with high quality building mixtures. It is one of the components of the self-leveling floor, decorative plasters);
• metallurgy (founding sand is involved in the creation of molds for casting. The resulting products have refractory properties and are highly durable);
• glass production (participates in the manufacture of glass containers, fiberglass, and other materials. Magnetic cleaning eliminates iron impurities from the material);
• construction (participates in the creation silicate bricks, concrete with refractory properties);
• housing and communal services;
• transport services;
• water treatment (included in the filters, due to the absorbent characteristics);
• animal husbandry (added to feed);
• production of composite electrical fuses (used due to dielectric properties).

Mineral deposits

Where to find quartz sand? This inorganic mineral is often found at the bottom, on the banks of natural reservoirs, in quarries. Its deposits are known in Russia, India, Switzerland, Burma and other countries. It is formed as a result of the decay of granite. In Russia, it is mined in the Bryansk, Moscow, Volgograd, Kaluga regions. Also, near Orenburg, in the Urals. There are deposits in the channels of the Samara and Ural rivers.

Mining Features

Quartz can be divided into primary and secondary. The first variety is formed directly during the decay of granite, located under a layer of clay, mixtures. This is a decomposed granite, which lies in one place for a long time, without being exposed to water, sun, air.

Secondary quartz is a mineral that is affected by water. Streams of water erode and carry it to other places. As a rule, accumulations form at the bottom of rivers.

Mining of primary quartz

It is extracted from the places of occurrence, transported for processing. Then the clay is dissolved, the quartz is dehydrated, calcined. The material is divided into fractions, packaged.

Extraction of secondary quartz

Raw materials are collected from reservoirs by a pump. Then the mixture is transferred to the places of accumulation. They form a quarry on the ground, collect deposits with the help of an excavator and other equipment.

crushed quartz

Received as a result of an explosion. Then processed into ground quartz sand. Used for sandblasting. Its sieving is optimal, and its composition is granulometric. This allows you to make sandblasting surfaces efficient. Crushed quartz can be used to clean metal, wood, plastic, glass, concrete and brick surfaces.

How to pick up sand

For each type of work, you need to select the sand of the appropriate thickness. Quartz sand can be fine, coarse-grained, medium in size. The larger the fraction, the more rough the processing will be.

The material is more expensive than ordinary sand. Its processing is not easy and cheap. The mineral is very durable and lasts a long time.

Photo of quartz sand

Majority basis building materials are natural components that have the necessary properties and are in sufficient quantity for industrial production. Quartz sand is one of the most common natural minerals and is used in all areas of construction.

What provides the chemical properties of the material

The main component of quartz sand is silicon dioxide (quartz). Its formula is SiO2. It may also contain organic impurities, clay, oxides of iron and a number of other metals. The content of quartz in the original mineral is usually not less than 93-95%.

The principle of operation of building mixtures used to obtain building blocks and slabs is based on the chemical interaction of the components. The resulting inorganic chains provide the required parameters of the material.

Silicon dioxide is an acidic oxide, therefore it reacts with calcium and aluminum compounds found in limestone and clay. The interaction can proceed both during the drying of the wet mixture and during thermal baking.

Varieties of quartz sand and its extraction

There are natural and artificial varieties of sand, which differ in the method of extraction.

natural natural

This type of sand is ubiquitous in nature and is found at the bottom of water basins and in the composition of the soil. Most of its grains are 0.2 to 1 mm in size.

There are several ways to extract quartz sand:

• quarrying- is the main way. If mining is carried out above sea level, then the resulting sand is called mountain sand. Varieties of soil sand are extracted during the development of soil on the plains. The appearance of quarry sand is characterized by pointed shapes and often a rough surface, which makes it a valuable building material. The extracted sand can be subjected to additional processing - screening, washing and drying. The more stringent the requirements for sand properties in any industry, the more thorough the preparation required. In the construction of small structures, sand is usually unaffected and supplied directly from the place of its extraction;
• development of water basins– the sand is washed out by the dredger and is characterized by high purity provided by natural washing. Mining is carried out in riverbeds, lakes, as well as marine areas. Sea sand is somewhat less valuable due to the higher content of mineral impurities. River sand has a smooth shape - under a microscope, the grains of sand resemble sea pebbles. The use of smooth (rounded) sands is common in self-leveling mixtures - sand grains do not cling to each other.

This is how natural quartz sand looks like in the photo

artificial sand

Despite the name, the mineral has a natural origin, but initially it is in the form of large crystals. To turn quartz crystals into sand, mechanical action (explosion) is used, after which the fragments are crushed.

Ways to classify quartz sand

The starting point in the classification system is the properties of the material and how it is prepared. There are the following areas of classification of quartz sand:

By size (fractional composition)

The numerical expression is the average value of particle sizes or their size range (fraction):

1. pulverized quartz - represents a fraction of less than 0.1 mm (sifted into a sieve with a pore diameter of 0.1 mm) and is usually found when crushing quartz crystals;
2. fine-grained sand - a fraction of 0.1-0.25 mm;
3. medium sand - fraction 0.25-0.5 mm;
4. coarse sand - a fraction of 0.5-1 (rarely up to 3) mm.

For enrichment

Quartz sand is divided into unenriched and enriched sand:

• raw sand is the original mineral that has not been treated to increase the silica content;
• enriched sand contains a few percent increased quartz content, obtained by removing most of the impurities. Thus, white quartz sand is purified from organic compounds, iron oxides and clay impurities by sifting, washing and drying.

Due to the nature of production, the main specifications received material. This, in turn, affects the possibility of further .

enrichment technology

High purity of the quartz mixture is a necessary requirement in a number of technological processes. The initial enrichment stage includes fractionation and washing - with their help, the coarsest impurities are removed.

The next step is the use of special technologies, such as:

• gravity enrichment- the main method, the essence of which is to separate the components of the mixture by density. The lighter particles are carried away by the water flow, while the heavier particles settle to the bottom of the apparatus. The gravitational effect can be enhanced by centrifugation or the addition of chemicals that change the wettability of the sand components;
• electrical and magnetic separation- is an impact electric shock and a magnetic field leading to the separation of some impurities. So, the magnetic effect is especially effective when cleaning from iron particles with magnetic properties.

The parameters of the enriched sand fundamentally affect the quality of the work performed. Sand mixtures with the best properties are produced only by certified enterprises using standard technologies.

By color

It is natural and dyed. Natural quartz sand is pale yellow to brownish yellow in color. Artificial dyeing is carried out with stable paints based on synthetic binders, allowing you to create original multi-color ornaments from sand. Such sand can be colored and white.

According to the degree of preparation

Depending on technological requirements, sand can be produced in the following varieties:

1. fractionated- represents a specific fraction of sand, the size of which is limited by technical regulations;
2. dry- air-dried. Together with fractionated sand, it can be used as a working medium for sandblasting machines;
3. calcined sand- completely dehydrated by calcination. Heating significantly above 100 °C ensures the desorption of moisture even from the deep pores of quartz. Such sand is used in finished building mixtures stored for a long time - even a slight moisture content can render the entire mixture unusable;
4. rounded quartz sand- has less abrasive properties, therefore it is suitable for delicate applications, for example, sandboxes on playgrounds;
5. molding quartz sand- used to produce cast quartz products and is characterized by a high degree of enrichment.

Production and extraction of quartz sand

On the territory of Russia there are a significant number of large deposits of quartz sand. The most famous are the Chulkovskoe (Moscow region), Kozlovskoe (Bryansk region), Elshanskoe (Volgograd region), Berezichskoe (Kaluga region) deposits and a number of others.

Differences of quartz construction sand, extracted from these places, are initially high quality parameters and higher cost. It is important to understand that the properties of sand from the nearest quarry will be quite sufficient for the construction of small summer cottages, so you should not overpay. If the goal is to build a large mansion, then saving on the quality of sand can negatively affect the durability of the house.

This is how quartz sand is mined on a special production line:

What are the characteristics of sand

The main regulatory document is GOST 2138-91, there are also other regulatory documents ( GOST 22551 77, GOST 51641 2000, 8736 93). They reflect the requirements for the main quality parameters and properties, namely:

1. the content of the clay component. Allocate 5 groups with established amounts of clay from 0.2 to 2.0%;
2. silicon dioxide content - from 99% to 93%, corresponding to groups from K1 to K5;
3. coefficient of uniformity, reflecting the variation in particle size relative to the average (in %). The higher the value, the more uniform the sand mixture. In total, there are five groups (from O1 to O5), differing in the coefficient of uniformity (from 80 to 50%);
4. fraction composition. This parameter reflects the average particle size of quartz sand: up to 0.14 mm; 0.14-0.18 mm, 0.19-0.23 mm, 0.24-0.28 mm, more than 0.28 mm;
5. humidity. Dry sands contain no more than 0.5% moisture, wet - no more than 4.0%, wet - no more than 6.0%;
6. in the composition of the sand, the content of metal oxides, the surface area of ​​the grains, their shape, gas permeability, as well as the weight loss upon ignition are also normalized.

Quality sand must have a certificate of compliance with the specified standards.

Operational properties of quartz sand

Material parameters that affect the quality of work and determine the scope of application include:

• bulk density - is about 1300-1500 kg / m3;
• true density - is in the range of 2600-2700 kg / m3. The value of true density is used in calculating the volume of cement or concrete mortar obtained by mixing the components;
• the thermal conductivity of quartz sand is about 0.30 W / (m? ° C). The shape and dimensions of sand granules have a significant effect on the heat-insulating properties - the denser their arrangement and the smaller the gaps, the higher the thermal conductivity coefficient;
• melting temperature - the maximum working temperature of quartz sand is estimated at 1050 ° C, which is quite enough for any construction work. When casting quartz products, temperatures of 1700 °C and above are used.
• normal quartz sand in a loose state has a bulk density of 1,500 kg/m3 and a bulk density of 1,600 kg/m3.

Advantages and disadvantages of the material - general assessment

Quartz sand is an almost indispensable component in many applications, and technologies with its participation have been worked out to perfection. For practicality, the material receives a "5".

The appearance of sand is familiar from childhood, and sand playgrounds are often associated with the beach and relaxation - for appearance also put a solid "5".

Despite the massive use of sand, its fine dust can lead to chronic diseases at the builders. For environmental friendliness, the material receives a "4".

The cost of sand is comparable to the cost of other building materials. Lacking special advantages in price, quartz sand deserves a rating of "4".

The approximate cost of various fractions of quartz sand is shown in the table:

Name	Cost, rub
Quartz sand VS-050-1	3000
Quartz sand fr.0.1-0.63	3200
Quartz sand fr.0.5-0.8	3750
Quartz sand fr.0.5-1.0	3750
Quartz sand fr.0.8-1.4	3950
Quartz sand fr.0.8-2.0	3950
Quartz sand fr.1,2-3,0	3950

Along with clay and limestone, quartz sand is one of the most important and necessary components for production and everyday life. The variety of material properties provides a wide range of applications. The presence of sand pits near the construction site significantly reduces the cost of building a house.