Separation of metals in the production of ceramics (case study)
17. 9. 2021
Filtration objective:
- Removal of tiny ferrous fragments from the glaze.
- Minimization of surface defects on the fi nished products (= reduction of reject rates).
Solution:
FIELD OF APPLICATION - PRODUCTION OF PORCELAIN AND CERAMICS
The production of ceramics and porcelain is a process combining traditional craft techniques with modern production methods - starting with creating simple mugs and plates up to complex design pieces. Each product goes through an accurate manufacturing process that includes shaping, drying, glazing, and firing.
These crafts are not only about technique but also about creativity and aesthetics, reflected in the final products.
WHY ARE MAGNETIC SEPARATORS USED IN PORCELAIN AND CERAMICS PRODUCTION?
In ceramics and porcelain industries the magnetic separators and filters are used to eliminate magnetic particle contamination. Our very powerful magnetic separators with a magnetic induction of up to 18,700 G can remove iron particles as small as 1 micron!
There are many reasons why it is useful to use magnetic filters in the production of ceramics and porcelain:
Quality of raw materials
The quality of raw materials such as kaolin, silica sand or color pigments directly influences the final quality of ceramics and porcelain. Even micron-sized iron particles are undesirable in these materials. The magnetic separator can reliably capture them.
The quality of the final product
The presence of metal particles in the ceramic material or glaze results in color stains on the final product. The magnetic filter removes them.
Reducing the number of complaints
Magnetic separators and filters ensure the quality of incoming raw materials and eliminate possible magnetic particle contamination. This leads to fewer internal and external quality complaints = higher profits!
SOLLAU
Manufacturer of magnetic separators for the porcelain and ceramics production
We are manufacturers of these separators. We manufacture them in our plant in the Czech Republic and thanks to this we can guarantee top quality and we can adapt them to your requirements.
WHERE DO OUR MAGNETIC SEPARATORS HELP IN THE PRODUCTION OF CERAMICS AND PORCELAIN?
Kaolin processing
The equipment typically preferable for handling kaolin:
Kaolin is processed in the dry state and that is why there are used magnetic separators for dry processing.
As the maximum purity of the final product is required, even micron-sized ferromagnetic contamination must be removed. For this reason, the strongest magnetic separators with a magnetic induction of up to 18,700 G are utilized. Depending on the degree of magnetic particle contamination, the customer decides between the separators with manual cleaning (most often the drawer magnets like MSS-MC) and the magnetic separators with automatic cleaning.
ased on our experience, we recommend the self-cleaning drawer magnets MSSJ-AC Tarantula. They are equipped with the strongest magnets generating an induction of up to 18,700 G and the magnetic grates which are placed in 4 rows above each other. The whole thus creates a perfect gravity (free-fall) style magnetic sieve that has no competition on the market.Thanks to this feature of our magnetic separators, we can perfectly separate even iron particles as small as 1 micron!
This provides exceptional performance at a price comparable to the rival 2-row separators.
These separators are often installed directly in the ceramics factory to treat, check and clean the incoming raw materials.
PHOTOS FROM PRACTICE
Separation of ferrous particles from ceramic mass and glaze
When producing ceramics or porcelain, it must be ensured that the ceramic material is completely free of iron particles. Similarly, the glazes, slips and body must be completely clean.
Even the slightest contaminants will cause visible color stains on the product after the final firing. The product devalued in this way has to be declared as a lower quality product, having an adverse effect on the company's economy.
Therefore, we use the following types of magnetic filters to separate magnetic particles from the liquid ceramic materials:
The simplest magnetic separators are magnetic rods - they can be placed anywhere in the material flow. And if, e. g., the liquid ceramic mass is conveyed through a chute, a hermetically closed magnetic grate can be used.
To achieve a perfect separation of any magnetic particles from the glaze or ceramic mass transported through the pipeline, we recommend that magnetic filters are inserted into the pipeline. If there is a small amount of iron contamination, we choose a magnetic filter with manual cleaning. In case of high degree contamination, we magnetic filters with semi-automatic or automatic cleaning should be applied.
The advantage of magnetic filters with automatic cleaning is the elimination of operator errors. Besides, our magnetic filters are fitted with the strongest neodymium magnets, so they can trap large amounts of magnetic particles. Their proper functioning is conditioned by regular cleaning, that is ensured thanks to the self-cleaning mode.
High gradient magnetic separators (called also wet high intensity permanent magnetic separators or matrix magnetic separators) represent a separate chapter in the magnetic separation. The ceramic mass or glaze flows through a matrix cassette filled with a magnetic stainless steel wool. A very intensive magnetic field (generated by the extremely strong neodymium magnets) gathers ferromagnetic contaminants inside the matrix. The secondary advantage of this separator is the fact that the stainless steel wool operates as a mechanical sieve at the same time and it is therefore able to catch also very small non-magnetic particles.
PHOTOS FROM PRACTICE
Removal of iron particles from shoes or work boots - avoidance of external sources of ferrous contamination
Most ceramics and porcelain manufacturers know and use magnetic separators and filters to remove iron contamination from raw and processed materials.
Another and often underestimated source of ferrous contamination are the company employees. These, moving from the workshop and maintenance areas, transfer iron particles on their shoes into the sensitive (= clean) production areas.
It is therefore necessary to separate sensitive production areas from service areas. We recommend using the following:
Magnetic mats are an easy and inexpensive solution, yet many companies underestimate this source of iron contamination.
PHOTOS FROM PRACTICE
Pot magnets
Using magnets in the ceramics industry is wider than just in the field of magnetic separation.
Magnetic pots are often used for clamping molds.
The advantage of the magnetic pots is embedding the magnet into a durable steel cup or channel. This cup protects the magnet from mechanical damage and the steel housing also concentrates magnetic force on one side and increases the holding power dramatically.
The housing can have different kinds of threads (internal or external), so using the magnetic pots is easy and fast.
Magnetic pots can be fitted with different types of magnets varying in strength and temperature resistance. We can supply magnetic pots resistant up to the temperature of 450 °C.
CASE STUDIES
CONTACTS
Do you have questions about our products? Do not hesitate to contact us!
Our sales team is ready to provide you with full support and help you find the best solution for your needs in the field of magnetic separation. We offer not only standard solutions but also tailor-made solutions. You don't have to worry about more complicated technical challenges. Just contact us and we will be pleased to help you.
You can contact us by phone, email, or via our web form.
+420 773 323 773
petr.zbranek@sollau.cz
