Permanent magnet application in ceramic production
Permanent magnetic materials and electromagnetic device produced magnetic fields source, besides has essential difference, they all have different contribution for the application of magnetic field. Electromagnetic device produced magnetic fields, due to its power, the input current, voltage is larger, and long time electricity, causing coil heat loss, magnetic field intensity peak height produce certain change, and rectifying electricity is easy fault happens, easy to produce "crash" phenomenon, the consequences of product quality greatly influenced. And permanent magnetic material, magnetic fields produced by magnetic circuit design, provide a constant magnetic field (i.e., within a long time, magnetic field intensity does not produce change). In recent years, using magnetic field (permanent magnetic field, electromagnetic field) to magnetic separation process ceramic materials of ferromagnetic materials, is people already familiar a clear ferromagnetic materials processing method. But how to use better and more refined, need to further understanding magnetic field and ferromagnetic materials. In addition, in the ceramic raw material processing process, the used water needs magnetization treatment, and it is helpful for ceramics forming and burned, and in mass production application
一 ceramic raw material deironing
Maybe someone will ask, ceramic raw materials "iron" is what?
The magnetic material, can be divided into four categories: (1) the ferromagnetic, (2) quasi ferromagnetic; 3 paramagnetic; 4 magnetic resistance. When the rnagnetizable rate are negative, the substance of magnetic performance is the magnetism resistance. When relative susceptibility were positive, but smaller than 1, display paramagnetic material called paramagnetic; When relative rnagnetizable rate larger than l substance called ferromagnetic material, and the material shows magnetic called ferromagnetic. Quasi ferromagnetic special case, not here narrative. Consequently, when the composition of the substance atoms don't have magnetic moment, can say as magnetic resistance. If the atomic magnetic moment is not equal to zero, meantime without interaction, and magnetic field is zero, the atoms magnetic moment direction is in completely without rules state, this is paramagnetic. If the atomic exists the interaction, the atoms magnetic moment are arranged parallel state, this is what we call the ferromagnetic.
We said ceramic raw material "iron," is this kind of ferromagnetic "iron". Only such iron can through the magnetic field from ceramic raw materials to clean.
Ceramic raw materials in the producing process, through all sorts of equipment mechanical broken, and multi-level long ball-milling, produce a lot of micron grade iron powder, we call this iron powder "mechanical iron powder", this kind of iron powder and ceramic raw materials mixed together, after burning into the existing in product of ceramic products black spots, the quality of its impact, visible in ceramic raw materials in addition to the importance of iron.
Currently, the industrial production deironing is devided into two categories: dry deironing and wet deironing. Dry deironing is mainly directed against the micron-grade powder deironing and ceramics forming former press and die protection deironing (belt conveying process). But the micron-grade propotrion due to cleanup processes, surface area increases an increased level of difficulty. Wet except iron is the most ideal deironing method. We've done a lot of experiment work: the choice of high-performance magnets, its technical parameters for: br p t, hc p 122 907ka/m, (bh) p 287kj/m3, from the actual need of work, and designed a kind of magnetic circuit, set-point the magnetic field strength greater than 4500 gaussian, magnetic field intensity relatively constant, operates more is better, the bigger work area the better. Why emphasize robustly and face? Because the water molecules surface tension is big, plus micron grade raw material surface area increases, ceramic raw materials when mixed with water, causing the mud affinity enhancement, if not high enough magnetic field intensity, enough magnetic robustly and working area, it was hard to deiron. Normally have 2 meters to 4 metres magnetic separation process to clean the ferromagnetic materials. If only emphasize and pursue high magnetic, and sacrifice magnetic field working area is not advisable. So a good magnetic field strength source must be relatively stable and constant magnetic field, the field work point is more and large area, can be regarded as a good magnetic circuit, which requires the scientific reasonable magnetic circuit design
二 magnetizing water and cermaic material
Magnetized water is water in flow process cuts magnetic line and magnetization, called magnetized water. The water molecule is an associating detached, certain quantum molecular groups and can simultaneously aggregation and body produce resonance is absolutely possible, the properties of water with magnetic field changes in a cyclical change, and change the system structure characteristics. For the flow water, every kind of ion after magnetic field of orbiting on behalf of their movement direction. From one point sport rotating into a plane movement in mutual face-to-face when rotating happened hydroxyl ions and water and hydrogen ions of separation. Water belongs to the polarity molecules, a water molecule is an electric dipole, n numbers of molecular is n numbers of electric dipole composite system. When the water molecule by a magnetic field at the effects of electric dipole in magnetic field rotation direction and degree inconsistencies, make n numbers of water molecules in n quantity smaller from associating fit into simple molecule of water. When boiling point magnetized water and the internal changes of water is similar, with the smaller of n quantity, the fluidity of water increases, this is ordinary water does not have.
Over the years, we have put magnetized water and ceramic raw materials mixture made a lot of experiments. The results of the tests is very ideal, the experimental results illustrate
(1) The water aerosols bonding process depends on the hydration rate and the size of the electric potential their surface. Water after magnetization to add solid particles to water, and its rally is different. The magnetized makes cohesion to strengthen, is helpful for dry forming molding and difficult deformation, crack is less, test sample after the roasting intensity increased 21.8%, density raised by 0.5 g/m3, porosity decreases
(2) Magnetized water dissolves ability has the relaxation structure, in ball-milling process, with prolonged, the raw material mixture of ball mill temperature increases, at this time inorganic material has good dissolution, soluble in magnetized water significantly, resulting in the formation of clay scattered things condensation and crystalline structure, raise the condensate structure characteristics. Commonly used water ceramic raw material mixture, after roasting no obvious form crystalling phase outline, and the use of magnetic water ceramic raw material mixture after roasting adjust crystalling phase, and promote crystallization increase
(3) Evaporation effect brings apparent economic benefits to production. Under atmospheric temperature conditions, according to the water volume and quality to measure evaporation speed, magnetic water evaporates 12% faster than untreated plain water evaporation speed, no exposed crack. These data proved magnetization treatment water had increased speed dry and burning into speed performance.
To sum up, under the application of magnetic water conditions, significantly alters the use normal water results: increase product intensity, reduce product porosity. Improve product quality, increase the economic benefit and has many benefits.
