Silica sand processing & Sand washing plant equipment expert

River Sand is a kind of small particle produced by repeated impact, collision or friction of stone by river in a long period of natural state. Sea Sand refers to the sand eroded by sea water without desalination, mostly from the junction of sea water and rivers, containing corrosive salts. River sand and sea sand are different, how to distinguish them? And what is different between sea sand washing plant and river sand washing plant?

1.Different Appearance between river sand and sea sand

In terms of appearance color, the sea sand is darker, dark brown and lighter. The color of river sand is relatively brightly yellow.

From the aspect of particle size, the grain size of river sand is coarser, with moderate surface roughness and less impurities. Sea sand is very fine, even some like powder, this is absolutely not used.

In terms of particle fragments, sea sand generally has fragments such as shells, while river sand has pebbles of different sizes.

2.Different Specifications between river sand and sea sand

The river sand used in the construction has certain specifications. In the process of river sand screening, river sand is generally divided into 4-8 mesh, 8-16 mesh, 10-20 mesh, 20-40 mesh, 40-70 mesh and 50-100 mesh, which refers to the number of sand particles within one inch circle. There is no such fine and clear rule classification for sea sand.

3.Different Handle between river sand and sea sand

Grab a handful of sand and then beat it off. It’s sea sand that feels sticky and doesn’t clean. If it’s not sticky, it’s river sand.

4.Different Taste between river sand and sea sand

Taste the taste, found that salty is sea sand, not salty is river sand. At present, there are also many Sea Sands that have been desalted. We can soak the sands in the water for a period of time and taste the taste of the water. The salty and astringent one is Sea Sands.

5.Different Ingredients between river sand and sea sand

The main composition of sea sand is silica, the crystal phase is mainly quartz, feldspar and debris particles are less, mica content is less, and the roundness is also good.

The silicon content of river sand is lower, the metal ions such as calcium and aluminum are more, and the mica sheet content is also more. But this is only an average situation in general, sometimes there are special cases, and it is difficult to have specific quantitative indicators.

Advantages of River Sand

Sand particles are smooth and clean;

It has a wide range of sources, convenient materials and low cost;

River sand has no taste, while sea sand has salt taste;

Quartz sand is a kind of quartz particle formed by crushing quartzite. Quartzite, also known as siliceous rock, is a hard silicate mineral with stable chemical properties, In nature, quartzite exists in the form of quartz sandstone, quartz shale and vein quartz.

Quartz sandstone is a consolidated clastic rock with quartz clastic content over 95%, which comes from various magmatic rocks, sedimentary rocks and metamorphic rocks, less heavy minerals, and associated minerals are feldspar, mica and clay minerals; Quartzite shale is divided into sedimentary rocks and metamorphic rocks; Vein quartz is formed by hydrothermal process, almost all of which is composed of quartz.

Quartz sand is milky white, sometimes colorless and translucent, its Mohs Hardness is 7. It is important industrial raw material.

In the sand washing plant, quartz sand through a variety of treatment processes by sand washing machine, can obtain a variety of uses of quartz sand products, used in all walks of life.

So how many types of quartz Sand

Quartz has high fire resistance. In industry, quartz sand is divided into ordinary quartz sand, refined quartz sand, high-purity quartz sand, fused quartz sand and silica fume.

1. Ordinary Quartz Sand

Ordinary quartz sand, that is, SiO2 ≥ 90-99%, Fe2O3 ≤ 0.06-0.02%, fire resistance 1750 ℃. Ordinary quartz sand is generally a kind of water treatment filter material made of natural quartz ore, which is crushed, washed, dried and secondary screened;

Ordinary quartz sand mainly used in metallurgy, silicon carbide, glass, enamel, cast steel, water filtration, foam alkali and sandblasting industries.

2. Refined Quartz Sand

Refined quartz sand SiO2 ≥ 99-99.6%, Fe2O3 ≤ 0.03-0.016%. It is made by complex processing of selected high-quality ore. Particle size range: 2-2500 mesh, can be produced according to the user’s requirements, white or crystalline appearance.

Refined quartz sand is mainly used for advanced glass, glass products, refractories, smelting stones, precision casting, grinding materials of grinding wheel, etc.

3. High Purity Quartz Sand

High purity quartz sand, SiO2 ≥ 99.5-99.9%, Fe2O3 ≤ 0.001%, made of high-quality natural quartz stone, carefully selected and finely processed. The particle size range is 0.005-0.01mm, 0.01-0.1mm, 0.1-0.5mm, 0.5-1mm.

High purity quartz sand is used to make glass, refractories, ferrosilicon smelting, metallurgical flux, ceramics, grinding materials, casting molding quartz sand and so on.

In the construction, it has strong anti acid medium erosion ability to make acid resistant concrete and acid resistant mortar.

4. Fused Quartz Sand

Fused quartz sand is a kind of filling material. Firstly, it oxidizes quartz sand by capacitance method, and then it is processed and screened by mechanical equipment. Finally, it becomes fused quartz sand. The fused quartz sand has thermal stability, high purity, stable chemical properties, uniform particle distribution, and thermal expansion rate close to 0 point.

Fused silica sand is used as filler in paint, coating and other chemical industries. It is also the main raw material for epoxy resin casting, electronic sealing materials, casting materials, fire resistance, ceramics and glass industries.

5. Silica Fume

The silica fume is processed from natural quartz and has large particle size range from 200 mesh to 10000 mesh. However, the fineness of silica fume is less than 0.001mm, accounting for > 80%, and the average particle size is 0.1-0.3 μm, which is a kind of dust state.

The production of foundry sand requires specialist screening and classification systems and involves detailed analysis of feed material and sand grade specifications. Foundry sand (also known as casting sand) consists primarily of clean, uniformly sized, high-quality silica sand that is bonded to form moulds for ferrous (iron and steel) and nonferrous (copper, aluminum, brass) metal castings.

The most common casting process used in the foundry industry is the sand cast system. Virtually all sand cast moulds for ferrous castings use green sand. Green sand consists of high-quality silica sand, bentonite clay (as the binder), water and coal (a carbonaceous mould additive to improve casting finish). The type of metal being cast determines which additives and what grade of sand is used. It is clear that particle size range is the most important criteria for the sand for foundry and also that it should not contain clay. If required the silica content can be enhanced thorough certain processes.

Sinonine has a high level of expertise in the production of sand for foundry application, developing its own screening and classification technology. Sinonine have developed a process for accurately separating the oversize particles and removing clay though the hydraulic classifier based washing system, which could be either single stage or double stage depending on the level of clay present. Finally the product is dewatered in the efficient dewatering screen resulting in a dewatered product having around 12 % moisture. In most instances scrubbing is also necessary to release the clay which is bound to the ore. This is usually done through drum scrubbers and attrition scrubbers either before or after screening of the raw sand. During these processes the silica levels in the product is also enhanced.

Sinonine has supplied a number of sand washing plant for the preparation of foundry sand all of which are operating successfully. The advantage of these plants is that the oversize of the screen (+600 µm) can be used for construction sand as all the silt has been removed. This makes our sand washing plant highly cost effective. The plants are also highly flexible and could be suitably modified by addition of scrubbing and gravity separation equipment to convert into plants for glass sand washing plant if suitable raw material is available.

High quality sand washing machine is the guarantee of high efficiency in sand washing plant Here we’re going to share six ways to improve efficiency of sand washing machines including the wheel sand washer and  spiral sand washer. 

Prevent debris from entering the charging port

The cleanliness and mud content of sand are one of the reasons for the decline in the output of sand washing machines. 

 During the cleaning process of the sand washer, it is necessary to prevent impurities from affecting the cleaning effect of the finished product. In addition, it is necessary to prevent materials with high hardness from entering the inside of the machine, which will cause wear to the equipment and reduce the service life.

Control the liquid level of the sand washing machine reasonably

If the liquid level is too low, the cleaning effect cannot be achieved; while the liquid level is too high, water resources are wasted, but the ideal cleaning effect is not achieved, and the ore is likely to overflow. The amount of materials for one-time cleaning must be within the specified range, otherwise it is prone to failure.

 Adjust the concentration to the critical value

 Ore concentration is the main factor that needs to be adjusted during the operation of the sand washing machine. It is related to the graded particle size and also related to the processing capacity under this particle size.

 The processing capacity of the sand washing machine reaches the maximum under the critical concentration. The critical concentration is related to the specified graded particle size and changes with the density of the ore and the mud content. 

The higher the ore density or the lower the mud content, the higher the critical concentration, and vice versa Of course, the relationship between the critical concentration and the graded particle size is the same as the mud content, that is, the lower the graded particle size, the smaller the critical concentration.

Clarify sand and gravel properties

The production capacity of the sand washing machine is related to the properties of sand and gravel, including the hardness, density, mud content, particle size of the sand and gravel materials. For example, the uneven sand and gravel materials and their own different attributes may affect the processing capacity of the sand washing equipment. The density of the material is directly proportional to the production capacity of the sand washing machine. The influence of mud content and ore size is mainly reflected in the viscosity of the slurry, which reduces the viscosity and increases the sedimentation speed of mineral particles. The processing capacity and classification accuracy of the sand washing machine will be better.

Make sure the installation location is appropriate

The sand washer should be placed in a suitable location, it can be placed on a flat ground, or placed at a high place, but the plane must be hard enough, and it must not be placed close to the water source. These places are prone to collapse. Cause unnecessary production troubles. In addition, there must be sufficient production space to ensure stable material transportation and production, and sufficient storage space for machine-made sand after cleaning to avoid secondary pollution.

 Daily inspection of sand washing plant equipment

 Before the machine runs, checking the equipment carefully is highly recommended. This rule is not only suitable for sand wash machines, but also for all kinds of equipment.

Here are some aspects you should checked before run the sand washer:

Check whether there are residual impurities in the bucket, discharge port, water storage tank, etc. of the equipment. If necessary, remove them immediately. Make sure that the passage of each component is unobstructed and clean.

Check the firmness of the equipment connection anchor bolts, take firm measures for loose bolts, and ensure the stability of the connection of the equipment components, especially the tightness of the screws.

The oil quantity of the reducer should be checked in time during operation, and the gear transmission of the equipment should be kept in good gear to ensure that the gear transmission belt is not worn or damaged.

The feeding of equipment should be ensured continuously and evenly, and it should not be too much or too little, which will result in insufficient material cleaning.

Each rotating bearing and reducer should ensure that the lubricant is sufficient and clean. At the same time, it is necessary to select a suitable lubricant to increase it. The lubricant of the reducer should be replaced on time after one month of use. The process must ensure the cleanliness of the equipment bearings and adding pipes to prevent contamination of the lubricant.

The sand washing machine should be cleaned in time after use, otherwise the pipeline will be blocked after a long time.

Regularly observe the internal wear and tear of the sand washer. If parts are found to be worn to affect production and operation, they must be repaired or replaced in time.

In the long-term production and operation process, the sand washing machine will affect the sand washing effect and efficiency due to various problems. If you also encounter this problem in future production, you may wish to check the above 7 aspects to find the right cause and prescribe the right medicine. 

The spiral sand washer (SL series) is able to wash and separate the soil and other impurities in sand and gravel aggregate. The enclosed structure, adjustable overflow weir plate, and reliable transmission parts increase the cleaning and dehydration effect, which can be applied to road, hydraulic, and construction industries.

The main features are listed below.

1.The structure is simple. The bearing device of impeller driving is isolated from the washing water and sand thus largely decreasing the failure rate.

The loss of fine sand and stone powder in sand washing process is small. The washed sand is of good gradation; the fineness modulus can easily meet the requirements of relevant standards.

Almost no components of the machine are vulnerable to wearing and breaking down except the screen.

An LS spiral sand washer is a kind of sand washing machine is mainly used for washing of mixed soil and dust in sand washing plant, along with the sand lifting in mining. The transmission parts of this machine are isolated from the water and sand, which largely reduce the failure rate during the operation process. The main features of this kind of machine are listed as follows.

The loss of fine sand and stone powder in sand washing process is small. The washed sand is of good gradation, the fineness modulus can easily meet the requirements of relevant standards.

The structure is simple. The bearing device of impeller driving is isolated from the washing water and sand thus largely decreasing the failure rate.

The washed sand is of high degree of cleanliness. Meanwhile, large operation capacity, low power consumption, and long service life can also he obtained.