artificial sand - what is it and how to make it | fote machinery
Artificial sand, also called crushed sand or mechanical sand (m sand), refers to rocks, mine tailings or industrial waste granules with a particle size of less than 4.75 mm. It is processed by mechanical crushing and sieving.
In China, the artificial sand was mainly used in the construction of hydropower systems. For example, the Three Gorges Project and the Yellow River Xiaolangdi Project used artificial sand to prepare concrete. Due to the remote environment of the hydropower project and the high quality of sand and gravel, the projects have taken the materials locally.
Many Indian states have decreed the use of crushed sand in infrastructure construction because of its high compressive strength and cohesion and the adverse environmental effects of river sand mining, which will greatly boost the demand for artificial sand.
There are both natural and human factors in the increasing demand for artificial sand. The former is that the natural sand is about to run out, while human factors include people's requirements for environmental protection and the need for high-quality concrete.
With the development of infrastructure, the natural sand resources formed by hundreds of thousands of years in many countries and regions have been almost exhausted, which has affected the further development of construction projects.
Driven by huge interests, natural sand has been indiscriminately mining, which changes the river course, affects the safety of river embankments, destroys the living environment of fish and contaminates the groundwater. The crushed stone sand is an important alternative resource to change this phenomenon.
In the process of mining river sand, it often produces a large amount of tailings which is not used reasonably. Especially in small mines, the tailings are piled up at random, occupying land and polluting the environment.
Besides, in urban planning and construction, a large amount of construction waste is generated, which actually can be crushed by the crushers to produce the artificial sand and aggregates for promoting resource utilization.
With the rapid development of concrete technology, the comprehensive performance of high-performance concrete and high-strength structural concrete has higher requirements on the quality of aggregates, requiring it with stable quality, good gradation and shape, while less and less natural sand meets the requirements. Therefore, people are turning their focus on artificial sand.
Artificial sand and mixed sand are mainly used in building construction, municipal construction, transportation, and other projects whose concrete strength grade is below C60. When meeting the corresponding technical requirements, they can also be used for concrete projects such as ports and water conservancy.
The vibrating feeder feeds the stone evenly into the coarse crushing machines for the primary crushing of the stone. The crushed stone from the coarse crushing equipment is transported through the belt conveyor to the fine crushing machines for the secondary crushing.
The primary crushing equipment directly processes supplied materials from the stone material factory and is the foremost processing plant. The jaw crusher is the ideal choice for primary crushing.
The secondary crushing equipment is responsible for the middle and fine crushing in the stone crushing process. The secondary crushing equipment mainly includes impact crushers and cone crushers.
The crushed material is conveyed by the belt conveyor to the crushed sand making machine for fine crushing. The finely crushed material is then screened through the vibrating screen for coarse sand, medium sand, fine sand and other specifications.
VSI sand making machine is called high cost-effective sand making equipment with low initial investment cost and good use effect. It is high in operation efficiency with the PLST crushing cavity.
The HVI sand making machine manufactured by Fote is more advanced in technology. Its butt ends and lubrication scheme are modular in design, and the peripheral guard plate can be turned up and down to extend its life cycle. It has the effects of sand making and shaping at the same time.
For those with strict requirements on the powder content of sand, a sand washing machine can be installed behind the sand manufacturing machine, and the sewage discharged from the sand washing machine can be recycled by the fine sand recovery plant.
The following video shows clearly the difference between crushed sand and river sand from the aspects of source, wastage, setting time, shape, silt content and so on. It is worth collecting and sharing with friends.
The table below shows the mix ratio of M15 M55 and M55 M55 concrete designed for artificial sand and river sand. The results show that in the same Concrete Mix Design, the strength of concrete by artificial sand is higher.
As the demand for aggregates from China, Africa, Latin America, Europe,etc. will continue to rise, and the price of artificial sand will also increase, the outlook for the global aggregate market for sand and gravel is worth looking forward to.
According to the Global Sandstone Aggregate report, by 2020, the demand for aggregates of sand and gravel in the Asia-Pacific region will increase the fastest in the world, and the growth rate of India, Vietnam, Malaysia, Indonesia and other regions will be among the best.
Due to the economic transformation, the demand for sand and gravel aggregates in China will slow down. However, the report predicts that by 2020, China will still be the world's largest aggregate demander, accounting for almost half of the world's total aggregate.
The Global Sandstone Aggregate report shows that the reserves of natural sand are gradually decreasing globally, and in some developing countries where the demand for aggregates and sand is huge, illegal sand mining has happened frequently. According to the report, by 2020, the reserves of natural sand resources in some countries will be quickly depleted.
The depletion of natural sand resources will lead to a sharp increase in the price of aggregates and artificial sand, especially in areas where the demand for aggregates is huge. It can be seen that the profit margin of the artificial sand is very large.
The m sand manufacturing machine produced by the supplier Fote is suitable for m sand making production line of high hard and abrasion-resistant materials such as limestone, quartz stone, granite, river pebble, basalt, cement, various ores, glass raw materials, mechanism building stone, gold slag, etc.
The limestone, widely distributed in nature, is easy to obtain. It is the main raw material for manufacturing cement, lime and calcium carbide. After being processed, limestone is used in large quantities as building materials. Generally, simple processing process is through the limestone sand production line.
Quartz is a hard, wear-resistant, chemically stable silicate mineral mainly composed of silicon dioxide. It is an important industrial mineral raw material generally used in glass, building materials, ceramics, high-tech electronics industry, etc. after crushing and sand making.
The granite has the characteristics of hard texture, high strength, abrasion resistance and weathering resistance. It has the title of "The King of Rocks" and is a good building material. It is rich in resources with low mining costs but high product value. Granite is a popular choice when the product needs to be weather-resistant or durable.
The river pebble resources are rich with low collection costs and high application value. After making sand from river pebble, it is widely used in water conservancy and hydropower, expressways, high-speed railways, passenger dedicated lines, bridges, airport runways, municipal engineering and high-rise buildings in the engineering field.
Basalt is the best material used for repairing roads, railways and airport runways. With the characteristics of strong compressive resistance, low crushing value and strong corrosion-resistance, it is the best cornerstone for the development of railway transport and road transport.
As a professional manufacturer of mechanical sand production equipment, Fote Heavy Machinery has rich experience in the design of mechanical sand production equipment, a perfect service system and professional after-sales team.
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what are the differences between artificial sand and natural sand? | hxjq
Since the amount of sand making machine is falling and more and more policies are set to protect the natural sand, the market for artificial sand (that is, sand and gravel aggregates processed by industrial sand making machines such as sand making machines and impact crushers) has shown great potential and vitality.
The artificial sand produced by the high-efficiency sand making machine has gradually replaced other machines in the market with its unique advantages and has become one of the main sources of building materials.
Sea sand often contains shells and other impurities, and its components such as the chlorine, sulfate and magnesium salts may cause corrosion of steel bars. All the components will affect the performance of concrete.
The main technical indicators of artificial sand are particle gradation, fineness modulus, stone powder content, void ratio, apparent density, bulk density, methylene blue value (MB), crushing value index, mica content, light-matter content, etc.
Due to years of exploitation, natural sand has become less and less. With soaring prices, the supply and quality of natural sand are not guaranteed. However, there are too many artificial sand resources. And it can produce artificial sand as long as there is stone. Urban construction waste, gravel tailings, stone chips, gravel, and mine tailings can be used as artificial sand raw materials.
The price of artificial sand varies from place to place, but it is basically much cheaper than river sand. Compared with river sand, artificial sand is about $3 per ton cheaper. In addition, the profit of the artificial sand is quite considerable. Based on the current market price of 2,000 tons per day, the estimated gross profit per month is more than 150,000 US dollars.
The traditional artificial sand production will bring environmental problems such as dust pollution. However, with the continuous improvement of the sand making process, the production now adopts a fully enclosed structure, and each machine has a water spray setting which prevents the dust from overflowing.
The arbitrary exploitation of natural river sand will change the shape of the bottom surface of the river bed, and then change the water flow direction, which will form complex flow modes such as vortex and reflow. These phenomena will further affect riverbeds, dams and river sandbars in a wider range by affecting the accumulation of sediments or causing sediments to be eroded, thus affecting river dike safety, bridge safety, and navigation safety.
The solid performance of the artificial sand is slightly worse than that of the river sand, but it still can meet the international sand standard. However, for the construction that is often subjected to frictional impact, the lime-sand ratio of the concrete, the crushing index and the stone powder content of the sand should be controlled.
Stone powder refers to the materials with a particle size of less than 75m mixed in the artificial sand. Generally, ordinary concrete requires less than 10% of stone powder, and high-strength concrete requires less than 5%.
Through the cement, mortar, and concrete test, there is no difference between the artificial and the natural sand. Generally speaking, the water consumption of artificial sand is slightly larger. However, the strength of concrete is basically unchanged.
The graininess of the artificial sand is more irregular. When it is bonded with building materials such as cement, it tends to have better adhesion, more compression resistance and longer service life.
According to surveys conducted by foreign professional research institutions, the global sand and aggregate market demand will reach 51.7 billion metric tons in 2019, with an average annual growth rate of 5.2%.
In the future, the estate industry in developed countries will recover, and the rise in per capita wages in developing countries will also stimulate peoples demand for modern housing. In terms of infrastructure, national investment and commercial investment will also be exerted at the same time.
In addition, according to the report, the storage of natural sand is gradually decreasing globally, and in some developing countries where sandstone aggregates are in great demand, the exploitation of natural sand has been prohibited by law.
The report shows that by 2019, natural sand reserves in some countries will be quickly depleted. The depletion of natural sand resources will lead to a sharp increase in the demand and price of artificial sand, so in the future, artificial sand production will be a good investment choice.
That is: the sand making process is that big stones are crushed coarsely by the jaw crusher, and sent to the impact crusher or the cone crusher for further crushing, and then the material is delivered to the sand making machine by the belt conveyor.
The wearing parts which are made of different materials have different wear-resistance ability. Wearing parts made of wear-resistant materials not only helps us save the replacement time, but also saves a lot of purchase costs.
Purchasing ability is one of the most important conditions when selecting equipment. When selecting a machine, please consider all the equipment conditions, and then combine with the cost to select the machine that suits you best.
Under the condition of natural sand depletion, the occurrence of artificial sand has alleviated this phenomenon in time. Through the above comparison, it is found that the artificial sand can be used as a good substitute for natural sand in infrastructure construction.
On the one hand, its own characteristics can meet the standards for construction. On the other hand, various ores such as limestone, basalt, quartz, andesite are widely distributed around the world. Many mines are still to be developed and utilized, so the artificial sand is a good investment market.
If you want to buy artificial sand production equipment, please consult the HXJQ Mining Machinery, our professional engineers will design the best artificial sand production line according to your specific needs, to help you choose the most suitable production equipment.
manufactured sand and crushed stones processing technology for concrete | quarrying & aggregates
Aggregate is the most exploited material in the world. It is an important component of concrete and asphalt concrete, accounting for 70% of the volume of concrete. It can inhibit the shrinkage and cracking of concrete and enhance the strength of concrete.
Aggregates are divided into natural aggregates and artificial aggregates. According to the degree of thickness, they are divided into coarse aggregate (crushed stone or gravel) and fine aggregate (sand).
Due to the non-renewable resources, the mining of natural aggregates is increasingly restricted. Now, in many countries and regions, the amount of artificial aggregate has exceeded the amount of natural aggregate, and it is widely used in various concrete industries.
Rock particles (excluding soft and weathered rock particles) processed by natural rock, river pebble stone or mine waste rock through mechanical crushing, shaping, screening, powder control and other processes, including:
The wet processing technology refers to washing with water during the screening and crushing of materials, and washing the coarse and fine aggregates with the stone washing machine and sand washing machine. Generally used for raw materials containing mud or more weak particles. When the finished sand and crushed stone powder content is too high, wet production can also be used to remove part of the stone powder.
According to the nature of the soil contained in the raw materials, the sand and stone washing methods can be divided into screen surface washing and sand washing machine washing. Which stone washing method to use can be determined according to factors such as the mud content of the raw materials, the nature of the soil, and the processing volume.
High water consumption, high cost of machine-made sand and crushed stone powder recovery and sewage treatment, serious loss of fine sand and crushed stone powder, and difficulty in dehydration of finished sand; when vertical shaft impact crushing machine-made sand is used, the sand formation rate is low.The wet production process is suitable for applications in areas with abundant water resources.
Generally, it means that the pre-screening is produced by wet method and the moisture content of the discharged material is controlled, and the sand making and screening system of shaping adopts the dry production process.
After the sand-making raw materials are washed with water, they must be dehydrated mechanically or naturally to ensure that the moisture content of the raw materials entering the sand-making machine is not more than 3%, otherwise the sand-forming rate and screening efficiency of the sand-making machine will be low.
No water or very little water consumption, less stone powder loss, dry processing technology is mainly used for raw material cleaning, high sand rate, low stone powder content machine-made sand and stone system.
(1) Due to the high moisture content of the dry processing raw materials or the high soil content of the raw materials, the fine aggregate is not easy to sieve through, and the soil content or fine powder content exceeds the requirements of relevant standards.
The 40 mm clean aggregate produced by multiple crushing and screening enters the sand making system. Sand making equipment generally uses a vertical shaft impact crusher. The principle of sand making is that some or all of the raw materials enter the high-speed rotating impeller and quickly rotate, and shoot out at high speed from the evenly distributed launch ports around the impeller. The flow or the raw materials piled in the cavity are broken by repeated high-speed collisions.
After screening and fine powder separation system sorting, qualified machine-made sand and gravel are processed. Fine powder separation is divided into two types according to different processing techniques:
Wet sand washing generally adopts a flat layout. The screened artificial sand flows into the sand washing machine for sand washing, and the washed fine powder and soil enter the integrated fine sand recovery and dehydration system for fine sand recovery.
The separated mud and stone powder enter the high-efficiency thickener for concentration and dehydration, and the concentrated and precipitated mud powder is pressed into a mud cake through a filter press.
The operating cost and floor space of a complete set of wet-process artificial sand making and sewage treatment equipment are about twice that of the dry process. Due to the high cost of equipment investment and land occupation rent, sewage treatment and dewatering waste residue discharge are also very expensive, so dry sand making has been rapidly developed.
The dry sand making fine powder separation system can be set up before or after screening. The plastic sand making machine and the screening fine powder separation system are connected to the large dust collector through a pipeline. The excess fine powder in the screened sand is collected by the dust collector and stored in the fine powder tank, which is regularly transported by the tanker for later application.
Dry sand making can be arranged in a flat layout or a three-dimensional layout in a tower. Since the tower-style complete set of equipment occupies only one-fifth of that of the traditional wet method and one-third of the traditional dry method Therefore, the tower-type machine-made artificial sand system is very suitable for building with concrete mixing plants or dry-mixed mortar mixing plants, reducing the transportation cost of finished artificial sand and crushed stone aggregates and storage facilities.
artificial sand manufacturing process - eastman rock crusher
In the sand artificial manufacturing process(sand plant), the raw materials are evenly fed into the jaw crusher machine for the primary crusher by the vibratory feeder. Then the crushing materials are conveyed to impact crusher and VSI sand making machine for secondary crushing(fine crusher). The belt conveyor transports the finally crushing materials to vibrating screen for separation. The require sand size product would be sent to the sand washing machine for clearance. The unrequested product will be returned to the sand making machine for repeated crushing until getting all the required size. The process of artificial sand making is complete.
There are mainly three steps of crushing, washing and screening in the artificial sand manufacturing process. The crusher machines of the crushing step may employ use jaw crusher, impact crusher, cone crushing, hammer crusher, sand maker. The artificial sand size different, the crushing equipment is different. The equipment of washing sand steps is a wheel sand washing machine or spiral sand washing machine. Spiral equipment washes much cleaner. Then the last step is to use sand screening machine for sand separation.
There are many materials that can make manufactured sand. For example, granite, basalt, river pebbles, pebbles, limestone, calcite, andesite, rhyolite, Diorite, diabase, sandstone, tailings, slag, quartz, etc. They vary in strength and grain size of artificial sands is because of the rock different. Exposition of the use of some rocks for making sand as follows.
The sand made of basalt mixed with concrete that can reduce the weight of concrete. And it is still very firm, also sound insulation and heat insulation. It is a good aggregate of lightweight concrete for high-rise buildings.
2. Operation and Maintenance.
Standard operation and regular maintenance can improve the sand production rate of the sand machine. If not, the crushing equipment wears parts will wear speed up, and reduce equipment life. The rate of sand making machine lessens.
Sand maker quality is good, not only energy-saving, environmental protection, and can easily achieve the expected output of equipment. JXSC who crushing machine manufacturers use new-high-wear-resistant materials and international more advanced production technology. Our equipment can meet the production requirements of customers. Provide a favorable guarantee for continuous, efficient and safe production
4. Project design.
The design of the whole sand plant must rationalize. The production plant not only requires a reasonable production capacity of the sand making machine, but also requires that the handling capacity of the jaw crusher, the cone crusher and the belt conveyor match it. Otherwise, the final sand production rate will definitely fail.
Artificial sand is produced by reducing larger pieces of aggregate into sand-sized aggregate particles. Manufactured sand can be manufactured to be a certain grain size that the buyer chooses, while natural sand can be a mix of coarse and fine grains. Manufactured sand tends to be more angular and flaky due to the crushing process. Highly angular particles tend to increase the paste content of concrete because additional lubrication is required for particles with sharp corners. Supplies of artificial sand are limited only by the capacity of those making it, and where natural sand is in short supply or logistically difficult to obtain, artificial sand is a better solution.
Natural sand has an ideal shape for use as fine aggregate in concrete. The natural sand particles are well-round and are usually nearly spherical. Spherical particles decrease the percentage of voids within the concrete mixture so no additional paste require to fill these voids. Well-shaped natural sands are ideal for workability of mixtures. Natural sand does not require more water to enhance the workability of the mixture so the amount of bleed water in the concrete will not be increased.
Long ago, when the industry was undeveloped, the river sand was not strictly controlled and could be mined by everyone. The method of mining mainly depends on manual mining. When the water is shallow, the sand-picking tools like Dustpan are put on the bottom of the river, and the sand-passing boat is pulled up bit by bit by manual force. Shipped Ashore, hand-picked to the sands.
Now, it uses mechanically mined, using gravel pumps to suck the sand directly from the river, and then loaded into trucks or piled up in coastal sand fields. But because excessive mining which destroyed the ecological environment, now, many countries are strictly prohibited from Mining River Sand. Therefore, the gravel pump is hardly used for sand mining, but for dredging, gravel suction, dredging channels, mining, and metal smelting slag transportation.
how about artificial sand compared with natural sand | m&c
Recent years, with the decrease of natural sand, the market of artificial sand shows great potential and vitality. And the huge demand of the construction market has promoted the development of the artificial sand market rapidly.
Artifical sand is a kind of sand material produced by sand-making equipment, such as impact crusher. Compared with natural river sand, artifical sand has the characteristics of sharp edges, many needles and flakes, and rough.
River sand is directly excavated from the river, so it will be mixed with small pebbles and fine sand. These small pebbles are washed by the river for a long time, and the edges and corners are rounder, while the artifical sand produced by sand and gravel equipment is more sharp and distinct, and the firmness is worse than river sand.
The firmness of artificial sand is slightly worse than that of river sand, and there is no problem in the use of ordinary concrete. But for concrete members, except admixtures, the lime-sand ratio and the content of stone powder should also be controlled.
High powder content is an important characteristic of artificial sand, which is different from natural river sand. When distinguishing, we should distinguish the powder content of artificial sand from the sediment content of natural sand.
The sediment content of natural sand refers to that the size of natural sand < 0.075 mm, which is composed of viscous clay and has a large plastic index. It has no connection with the hydrated crystalline stone of cement. Therefore, the sediment content of natural sand directly affects the strength of concrete.
The powder content of manufactured sand refers to the fine rock powder < 0.075 mm. It can not react with cement hydration, but it has excellent relationship with cement crystalline stone and plays a filling effect of micro-aggregate.In fact, if the powder content of manufactured sand < 20%, it has no adverse effect on the cohesion time and strength development of concrete, but has greatly impaction on the workability, pumpability and strength of concrete mixtures.
For natural sand, one kind of fineness modulus can be graded in many ways. The fineness modulus of machine-made sand can be controlled artificially by production process, and the production can be organized according to users requirements, which is impossible for natural sand.