The aluminum liquid degasser is the key equipment for aluminum refining, and the graphite rotor is one of the key components of the equipment. The graphite rotor is composed of two parts: a rotor rod and a nozzle.
In the aluminum refining process, the aluminum liquid degasser transmission system drives the graphite rotor to rotate at high speed, and argon or nitrogen is sprayed into the aluminum liquid through the rotor rod and the nozzle to remove the hydrogen and oxide inclusions in the center of the aluminum liquid, so that the aluminum liquid can be purified.
Generally, graphite rotors are made of graphite materials. Graphite is easily oxidized in the air above 600 ℃, and there is no protective atmosphere in the degassing box. The temperature of the molten aluminum can reach about 900 ℃, and the graphite rotor is exposed to red heat in the air. State, oxidation is inevitable, and the result of oxidation makes the rotor shaft gradually thinner until it breaks and is scrapped.
In addition, the graphite rotor is immersed in the aluminum liquid, and generally rotates at a speed of 300 ~ 700r/min and strongly stirs the aluminum liquid. The molten aluminum will cause strong erosion and wear on the rotor, especially the interface between the graphite rotor and the molten aluminum. Corrosion, erosion, abrasion, and air oxidation exist at the same time, making the graphite rotor gradually thinner at the three-phase interface until it breaks. scrapped. Therefore, how to improve the oxidation resistance of graphite rotors and resist the corrosion, erosion and wear of high-temperature aluminum liquid is the key to prolonging the service life of graphite rotors.
Technicians have done a lot of research work to improve the service life of graphite rotors. On this basis, an aluminum dihydrogen phosphate material with high oxidation resistance, corrosion resistance, erosion and abrasion resistance of molten aluminum was prepared, and a complete set of processes for treating graphite rotors with this material was developed. Through this treatment process, the service life of the graphite rotor is increased by more than 5 times than the service life of the graphite rotor processed by pure graphite, and the process is simple, easy to process, and low in cost, and has a wide range of application prospects.
Aluminum dihydrogen phosphate has high temperature resistance, corrosion resistance, thermal vibration resistance, erosion resistance, oxidation resistance and other properties, and has good wettability with graphite materials, and has poor wettability with molten aluminum and does not react. Using the pores of the graphite material, the aluminum dihydrogen phosphate is immersed in it, and then solidified to convert the aluminum dihydrogen phosphate into aluminum polyphosphate. The surface and pores of the graphite rotor after the treatment are filled with aluminum polyphosphate, so that a layer of aluminum polyphosphate protective film is formed on the surface of the exposed graphite particles, and the graphite does not directly contact the air and high-temperature aluminum liquid. This not only increases the density of the graphite rotor and the strength of the graphite rotor, but also greatly improves the oxidation resistance of the graphite rotor and the corrosion, erosion and abrasion resistance of the molten aluminum, thereby greatly improving the service life of the graphite rotor.
Aluminium Liquid Degasser ni vifaa muhimu kwa ajili ya aluminium kusafisha, na rotor graphite ni moja ya vipengele muhimu ya vifaa. Rotor graphite ni pamoja na sehemu mbili: rod rotor na nozzle. Katika mchakato wa kusafisha alumini, mfumo wa uhamisho wa gesi ya alumini ya kioevu huendesha rotor ya graphite kuzunguka kwa kasi kubwa, na argon au nitrojeni huchapwa kwenye kioevu cha alumini kupitia rod ya rotor na nozzle ili kuondoa hidrojeni na oksidi ya ndani katikati ya kioevu cha alumini, ili kioevu cha alumini kiweze kusafishwa. Kwa ujumla, rotors graphite ni kufanywa ya vifaa graphite. Grafiti huathiriwa kwa urahisi na oksidi katika hewa ya juu ya 600 ° C, na hakuna mazingira ya kinga katika sanduku la kuondoa gesi. Aluminamu iliyoyeyushwa inaweza kufikia joto la 900 ° C, na rotor ya graphite hufunuliwa kwa joto nyekundu. Hali ya oxidation ni ya lazima, na matokeo ya oxidation hufanya shaft rotor hatua kwa hatua nyembamba mpaka kuvunjika na scrapped. Kwa kuongezea, rotor ya graphite imezamishwa katika kioevu cha alumini, na kwa ujumla huzunguka kwa kasi ya 300 ~ 700rpm na kuchochea sana kioevu cha alumini. Aluminium iliyomwagika itasababisha mmomonyoko mkubwa na kuvaa kwenye rotor, haswa kiunganishi kati ya rotor ya graphite na alumini iliyomwagika. Uharibifu, uharibifu, abrasion, na oksidi ya hewa zipo wakati huo huo, na kufanya rotor ya graphite hatua kwa hatua kuwa nyembamba zaidi katika kiunganishi cha awamu tatu hadi inavunja. zimeharibiwa. Kwa hiyo, jinsi ya kuboresha upinzani wa oxidation ya rotors graphite na kukabiliana na kutu, uharibifu na kuvaa ya maji ya alumini ya joto la juu ni ufunguo wa kupanua maisha ya huduma ya rotors graphite. Wataalamu wa teknolojia wamefanya kazi nyingi za utafiti ili kuboresha maisha ya huduma ya rotors graphite. Kwa msingi huu, alumini dihydrogen phosphate nyenzo na high oxidation upinzani, upinzani wa kutu, erosion na abrasion upinzani wa alumini kuyeyuka ilikuwa tayari, na seti kamili ya taratibu kwa ajili ya matibabu ya graphite rotors na nyenzo hii ilitengenezwa. Kwa njia hii, maisha ya huduma ya rotor ya graphite huongezeka kwa zaidi ya mara 5 kuliko maisha ya huduma ya rotor ya graphite iliyotengenezwa na graphite safi, na mchakato ni rahisi, rahisi kusindika, na gharama ya chini, na ina upeo mkubwa wa matarajio ya matumizi. Aluminium dihydrogen phosphate ina upinzani wa joto la juu, upinzani wa kutu, upinzani wa vibration ya joto, upinzani wa erosion, upinzani wa oxidation na mali nyingine, na ina wettability nzuri na vifaa vya graphite, na ina wettability duni na alumini iliyomwagika na haina athari. Kwa kutumia pores ya graphite, alumini dihydrogen phosphate huingizwa ndani yake, na kisha huimarishwa ili kugeuza alumini dihydrogen phosphate kuwa alumini polyphosphate. Kwa upande mwingine, sehemu ya juu ya rotor ya graphite hujazwa na polyphosphate ya alumini, na kwa hivyo, juu ya sehemu ya juu ya chembe za graphite, kuna safu ya filamu ya ulinzi ya polyphosphate ya alumini, ambayo haikuwasiliana moja kwa moja na hewa na kioevu cha alumini cha joto la juu. Hii si tu huongeza wiani wa rotor graphite na nguvu ya rotor graphite, lakini pia inaboresha sana upinzani wa oxidation ya rotor graphite na upinzani wa kutu, erosion na abrasion ya alumini iliyomwagika, na hivyo kuboresha maisha ya huduma ya rotor graphite.