■ The one and only technology for liquid purification.

■ The one and only technology for liquid purification.
The number of ISO 14001 certified sites has exceeded 6,000 (as of the end of March 2001), and even now, certification is being acquired at a rate of 200 sites per month, further accelerating the momentum.
One of the issues that is always mentioned by these ISO 14001-certified sites is the treatment of wastewater and effluent.
In addition to complying with the legal requirements, recently each factory has been seeking a "factory wastewater recycling system" that produces as little wastewater as possible.
In the field of wastewater treatment at certified sites, which are under pressure to continuously improve, a step up in the field of wastewater treatment would be the "wastewater recycling system.
Liquid ConSand Corporation is a pioneering venture in the development of factory wastewater and effluent recycling systems.
In particular, its coolant (grinding fluid) recycling system is attracting attention for its ability to significantly reduce machine tool machining costs and achieve zero wastewater.


● Technical challenges in recycling factory wastewater.
President Kimihiko Okagami explains the motivation for starting the business.
I had been looking at factories for a long time and thinking that they were discharging wastewater without treating it.
I wanted to do something about this, so I founded the company about 17 years ago.
Initially, we worked on lubricating oil purification, but lubricating oil was in sealed containers and circuits, and no matter how clean it was, it could not be visually checked, so we could not get a fair evaluation.
Therefore, we switched our development to the purification of coolant and cleaning fluids for machine tools, where the condition of the fluids could be checked from the outside at a glance.
That was in 1986.
Most factory wastewater and cleaning fluids can be reused and their life extended by removing particulates, bacteria, and emulsified oil from them.
However, until now, there have been technical challenges in recycling factory wastewater.
For example, particulates in coolant solutions for silicon, ceramic, and glass polishing are less than 0.4 micrometers in size.
Also, the particle size of oil that has been completely emulsified and mixed into the cleaning solution is extremely fine, at 0.51 micrometers.
To remove such particles smaller than 1 micrometer, a filter smaller than 1 micrometer must be used.
Currently, however, only ceramic filters are available, and even these filters clog quickly and cannot withstand use.
Therefore, the current situation is that a large amount of liquid is poured onto the outer surface of the ceramic filter, and a portion of the liquid is forced through the filter by osmotic pressure.
Also, until now, the only methods for removing heavy metal ions from wastewater have been the use of polymer coagulants or chelating resins.
However, polymer flocculants require 3040 minutes for coagulation and sedimentation after addition, and require a huge area of equipment such as a sedimentation bed.
In addition, the addition of large amounts of expensive flocculants and the treatment of sediments required a large amount of money.
On the other hand, although chelating resins can be used in relatively compact facilities, they generate a large amount of concentrated liquid waste during regeneration, which requires a high-molecular flocculant for treatment.


The new system uses an adsorbent to flocculate and a filter to capture the flocculant.
The SA Filter, a coagulation and filtration device that uses a special adsorbent, was developed to overcome these issues.
We have spent three years developing and perfecting this coagulation and filtration device, and by combining it with various oil-water separation devices, we provide various types of factory wastewater recycling systems.
Simply put, the principle of the SA Filter is that by passing liquid through a special adsorbent developed by our company, the fine particles, bacteria, and emulsified oil in the liquid are agglomerated into a mass approximately 300 times larger than each other, and captured by a coarse filter.
In other words, particles as small as 1 micrometer can be captured by a 100 micrometer filter, and particles as small as 0.1 micrometer can be captured by a 10 micrometer filter, whereas previously only hollow fibers could capture them.
On the other hand, oil that is completely emulsified and stuck to the liquid surface becomes a large mass when it passes through the adsorbent, but because oil is a liquid, it passes through the filter in an elongated and deformed form.
For this reason, an oil-water separator with a specific gravity difference is installed at the rear of the SA filter, and the oil that has become a large lump is allowed to rise to the surface of the liquid for collection.
It has been reported that the introduction of this SA filter has reduced the amount of factory waste liquid to less than one-tenth, or even to zero depending on the type of liquid.
At the beginning, although the company recognized the quality of the product, it took years of testing before it was delivered.
When we delivered the product to a factory, the factory workers used to wear masks and nose plugs because of the foul odor of the liquid waste, but now they can eat their lunch inside the factory," said President Okagami.


The company's mainstay business is currently the introduction of machine tools.
The company's two main businesses are recycling systems for machine tool coolant and systems for removing heavy metal ions from wastewater.
In the machine tool coolant recycling system, we have developed a system that reduces coolant waste to almost zero and can also reduce the capacity of the coolant tank to one-fifth of the conventional coolant tank capacity.
We are also currently working with Sumitomo Densetsu to develop individualized systems for various types of machine tools and an in-hand management system.
On the other hand, in the heavy metal ion removal system for wastewater, we have developed and deployed a compact, inexpensive, and low-running cost system using SA filters in collaboration with Sumitomo Densetsu.
The system can remove heavy metals such as lead, nickel, copper, and hexavalent chromium without using polymer coagulants.
We have also developed a system that can recycle dicing liquid (tap water) for LCD glass substrates, which has attracted much attention.
This system circulates 160 liters of dicing liquid per minute while purifying it during the 24-hour continuous cleaning process.
The system was delivered in September 1997 with a processing capacity of 200 tons per day (order amount: 10 million yen), and has been in continuous operation with zero wastewater.
The price of the SA filter is approximately 2.3 million yen per unit for the standard model K350G50 (flow rate: 60 liters/minute of water and 20 liters/minute of oil).
The price is set at less than one-fifth of the initial cost and less than one-tenth of the running cost, while having the same treatment capacity as equipment using a hollow fiber filter capable of removing particles as small as 0.1 micrometer, a ceramic filter capable of removing particles as small as 0.3 micrometer, and a polymer coagulant capable of removing heavy metal ions. The price is set at less than one-fifth of the initial cost and less than one-tenth of the running cost.
Environmental protection measures are usually viewed as a cost factor, but the company's policy is to reduce costs through the introduction of waste fluid recycling systems and other measures.
In addition to reusing the fluid, the coolant recycling system for machine tools can reduce the capacity of the coolant tank to about one-fifth of the conventional coolant tank capacity, making the machine tool more compact.
This has the advantage of significantly reducing the footprint of the machine tool.
Another cost benefit is that the machine tool can be maintained in its initial condition based on the concept of total product management (TPM), thereby extending its service life.
The number of machine tools (grinding machines) produced in Japan is approximately 6,000 units/year.
For the time being, we would like to sell SA filters to 10% of newly built machine tools in Japan, or 600 units per year, and eventually to 60%, or 3,600 units per year.
We also have our sights set on global expansion (global production is approximately 24,000 units/year).
As for patents, we have already obtained 4 patents including international applications and business patents, and have 3 other patents pending.
The company has none of the sales staff and needs to partner with large companies for major business negotiations, which is a common problem for technology-related ventures.
President Okagami is also aware that the company lacks in all aspects of human, material, and financial resources when considering global expansion.
However, it is a fact that this is a unique technology in the world.
When it comes to liquid purification, we are technologically unbeatable even when compared to the top major companies.