About “SUN” (Sand Unit Novel) -Sand manufacturing system-

In 1969, KORITSU developed a crusher for specifically manufacturing sand for the first time in Japan.

Since that time, KORITSU has been continuously improving the technology of manufacturing sand. 

The magnum opus that bring together our technologies is SUN.

KORITSU is the oldest company that tests and produces sand manufacturing systems in the world.

Sand manufacturing method

The sand manufacturing method used by SUN came from observing the process of river stones becoming river sand within the natural world.

When larger stones flow downstream, the stones are crushed and improved grain shape results by them being ground against rocks on the riverbed, other stones and with each other, simultaneously dust filler is washed away. In other words, the process whereby stones become river sand in nature is sequential : performed size distribution control by crushing, grain shape improvement, surface polishing and the removal of filler dust at the same time. 

Subsequently, SUN mimics these actions and performs size distribution control by crushing, grain shape improvement, surface polishing and the removal of filler dust at the same time. In addition SUN manufactures sand that meets the industry standards for concrete sand in just one-pass. However, because SUN is a dry type sand manufacturing system, an external water source for washing dust filler away like the river sand is not required. Making it eco-friendly also.

-Real customers’ feedback-

In a sense, all machines have ‘birth’ (when they are able to achieve the purpose designed by their architect), and all were born with various roles in mind. So it is necessary for us to keep in mind what the original design was for at the  ‘birth’ of the machines we wish to purchase. Recently we have seen a manufactured sand industry boom. However with newly designed machines, their makers are experiencing many troubles regardless of the numerous renovations made to their original sand crushers  design. As their machines other components were designed to work with their original crushers at their time of ‘birth’. In that sense, SUN was born 35 years ago as a sand crusher, and has since then been developed and improved over a very long time frame so as to have achieve its high quality. It growth has been completed. That’s the difference between SUN and other infant model crushers.

System constitution

SUN is comprised of an innovative sand manufacturing crusher termed the EXCELLENT REFINER (EXR) and resourceful dust collector directly connected to EXR. It is a compact and simple system. There is no requirement for any auxiliary equipment for example, an air classifier or a washing plant, particle shape improving equipment.
So you can activate the plant fast.

-Real customers’ feedback-

“It’s was surprising to see how fast you could activate the plant.”


1. The role of “EXR” in the sand manufacturing method of SUN

About EXR -A masterpiece of sand manufacturing crusher-

Because EXR looks like an ordinary Horizontal Shaft Impact crusher (HSI),  you may be misled in thinking that the throughput capacity of EXR (50t/h) is very low for a HSI. However EXR is no ordinary HSI, but actually a unique dry-type crusher for specifically manufacturing sand. Therefore, as a sand manufacturing crusher, EXR achieves astonishing production efficiency of sand in just one-pass (you can achieve about 85 to 90% of the throughput raw materials as sand product). And since EXR can perform size distribution control very easily and flexibly, you can also easily manufacture high quality sand that meets the high standards required for concrete sand.

◆ Savings on running costs by incorporating the highest level of anti-wear protection

EXR‘s hammers are made of ceramics. The life of ceramic comprised hammers are 60 times longer than conventional hammers. 
Typically, ceramics are extremely resistant against friction motions, but not against shock motions. Because of that fact ceramics are usually not used in the manufacture of hammers for use in crushers. However, through our rigorous research and development we have devised a method to overcome this weakness and allow us to produce hammers composed of ceramics.

Of course other key components are also made of special anti wear material too. So you will greatly save on your running costs.

-Real customers’ feedback-

“We are grateful to you that you listened to our response to try and keep purchasing costs low. However, we were lost for words to see you did not discount the cost of machine but instead cut our continuous running costs. Our final desire was to cut the costs in the long term also. Your consumable breaker plates last around 60 times longer than our previous equipment used in the past. This is unreal. YOROSHIKU”


◆ Eco-friendly

Low noise (the noise level produced by EXR is less than 80dB directly beside the machinery, and around 55dB without any obstacles 10 meters away from EXR), low vibration.

-Real customers’ feedback-

“We don’t need to wear earplugs anymore. We can comfortably talk to each other without using them now.”


Crushing for size distribution control and improving grain shape at the same time

EXR has four processes as demonstrated below.

    Stones are crushed by hammers rotating at high speed.
    Consequently, product size distribution can be controlled easily by simply changing the rotating speed of the hammers.

    Stones are pounded with hammers whilst striking the wall of the crushing chamber. During this process, the stone will be crushed and grain shape will improve further with the collision against the specially designed breaker plates attached to the crushing chamber wall.

    Stone particles grind against each other in the crushing chamber.


EXR is equipped with a “rooster (grate bar type screen)” at the discharge point of the grinding product within the crushing chamber. This is the prime difference from an ordinary HSI. Product size distribution can be controlled easily by changing the setting of the clearance size between each bar of the rooster. 
Stones that are unable to passed through the clearance between each bar of rooster are crushed again within the crushing chamber. Therefore, you can achieve production efficiency at approximately 85 to 90% in just one-pass. 

-Real customers’ feedback-

“Frankly speaking, the shape of the sand is fantastic.”

“(To return the oversize material again in a later process) they said the ability of the sieve wasn’t good enough, but it is actually working very well. Why? The efficiency of the crusher is great, so that it creates little oversize material anyway! Oh this is what you call efficiency. I got it, I understand it now.”


Removal of filler dust

The amount of filler dust generated by EXR is only about 10 to 15%. Furthermore, by circulating particles in the crushing chamber, the surface of the sand grain is polished and any filler dust that has attached to the surface of sand grain can be separated. In the next process you can remove filler dust easily by incorporating the resourceful dust collector.   

-Real customers’ feedback-

“The problems we need to face is the excess amount of filler produced. It is quite difficult to deal with. We should choose a machine which creates less sand filler. And so we found it! As the amount of filler this machine creates is very low.”


Data about sand product by EXR


2. The role of “the resourceful dust collector” in the sand manufacturing method of SUN

Collecting filler dust and size distribution control at the same time 

Typically, a dust collector is used for it’s original purpose of preventing dust scatter. In addition, however it also assumes the role as a classifier in SUN. So there is no further requirement for any additional classifier. Product size distribution can be controlled easily and simply by adjusting the air volume of the dust collector.


◆ Eco-friendly

There is almost no scattering of excess dust. A water source is not required and no wastewater or sludge is produced.

Excellent system for the removal of filler dust

Commonly, it is said that it’s difficult for dry-type sand manufacturing processors to remove filler dust as an air classifier can not remove the filler dust that has been attached to the surface of the sand product. 

Within SUN, the resourceful dust collector is directly connected to the EXR as shown in the diagram. This is very important to effectively remove filler dust from the sand product. 
Sand product and filler dust are separated and heated through the crushing process by EXR, making them both “Non-cohesive”. As the filler dust is removed by the SUN dust collector while both particles are still “Non-cohesive”, accurate de-dusting can be done.
This can only be achieved because of the low generation amount of the filler dust produced by EXR (only about 10 to 15% of throughput). 

Data about sand product by SUN


-Real customers’ feedback-

“Are you sure you can produce so much sand as stated?”

“Where do you sell this sand?”

“It’s a good idea to sell this sand with it’s own brand name, due to the high quality and consistent size.”


3. How to control product size distribution in the sand manufacturing method of SUN

When it comes to particle size distribution, there is no doubt that it is important to manufacture sand that meet the required industry standards. However, particle size distributions that individual customers require, generally vary with each order. Therefore, to manufacture sand that sells well is to manufacture sand that your customers want.

SUN can perform size distribution control very easily and flexibly through the following three methods. Therefore, you don’t need specialized knowledge or training to operate SUN.

1) By changing the rotating speed of EXR’s hammers via a volume switch on the control panel.
2) By adjusting the air volume of the resourceful dust collector via a volume switch on the control panel.
3) By setting change to the EXR’s “rooster”.


So you can manufacture sand that meets the required standards and customers requirements consistently(you can manufacture sand that sells well). Furthermore, you can manufacture plaster sand that meets ASTM C 897 (American standard). 

  • The gradation comparison between ASTM C 897 and product by SUN (Remove over 2.36 mm materials in SUN sand by screening).

  • Internal finish by using plaster sand that was manufactured by SUN.

  • Comfortably achieve a minimum mix ratio of 1:6 (Cement : Sand).
-Real customers’ feedback-

”We are actually meeting the needs of the customer regardless of  whatever sand particle size they require. This machine can make rough sand as well as fine one depending on whatever they want.”



SUN (Sand Unit Novel)

Model SUN-2150
Max. throughput (T/H) 50※1
Max. permissible throughput size (mm) 8※2
Over all power consumption (kw) 152.2
Dimensions (mm) W5765 × D8767 × H8142

※1 Varied by types of rock and size being fed and the clearance between each bar of the rooster.
※2 Varied by types of rock being fed and the clearance between each bar of the rooster.

    Water mixture for SUN

    Typically we recommend you to put the sand product through a water mixture in the final process of manufacturing sand. Adjusting sand with water, particle size distribution becomes even during storage. By using SUN you can manage your sand product quality easily and stably.


    Max. throughput (T/H) 50
    Over all power consumption (kw) 5.5
    Dimensions (mm) W5834 × D3314 × H3295


    Sand manufacture plant (example) 

    Hopper for raw materials
    SUN-2150 (discharging dust filler from dust collector)
    Vibrating screen (returning over size particles to hopper)
    Water mixture



    is required.

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    1147, Kusakabe, Tsuyama-city
    Okayama, Japan-7081117