Aluminum plate and strip rolling includes hot rolling of aluminum plate and strip mainly producing medium and heavy plate and aluminum coil and cold rolling mainly producing aluminum plate, strip and foil. The lubricants used in the aluminum rolling process mainly include emulsions for hot-rolled aluminum sheets, rolling oils for cold-rolled aluminum sheets, rolling oils for aluminum foils, and oil-water application technology for cold-rolled aluminum sheets. The emulsion for aluminum hot rolling is prepared by hot rolling oil and water. The concentration of the emulsion is usually in the range of 2~10%, of which water accounts for about 90~98% of the emulsion. Therefore, the aluminum hot rolling emulsion The water in the aluminum hot rolling plays a very important role in the production of aluminum hot rolling and the quality of the strip.
Selection and Influencing Factors of Emulsion Dosing Water in Aluminum Hot Rolling 1. Use natural water to mix Calcium and magnesium ions in natural water are the most harmful to the emulsion. Calcium and magnesium ions can form insolubles with emulsifiers and some active ingredients in the emulsion, which have a great impact on the stability of the emulsion and the efficacy of the active ingredients. They not only affect the stable use of the emulsion, but also affect the stability of the emulsion. It may affect the normal operation of rolling production. In addition to calcium and magnesium ions, other ions in water will also have adverse effects on the emulsion. For example, excessive Na+ content will increase the tendency of water corrosion and reduce the chemical adsorption of active ingredients in the emulsion. Emulsions prepared with high hardness water, in which sulfates or oxides are present, will also reduce the stability of the emulsion. 2. Use demineralized water to mix Because calcium and magnesium ions are more harmful, people use sodium ion exchange resin to replace divalent calcium and magnesium with monovalent sodium, which reduces the harm caused by calcium and magnesium ions to a certain extent. . Replacing calcium and magnesium with sodium reduces the hardness of the water a lot, but the amount of metal ions in the emulsion does not decrease, so the conductivity does not change significantly. This situation occurred at a customer. Due to the high conductivity of the softened water (sodium ion exchanged water) used, a large number of sodium ions accumulated rapidly. When the conductivity of the emulsion reached 1500uS/cm, the rolling surface quality Problems started to occur. After this user switched to deionized water, their production and use of the lotion were significantly improved. As mentioned above, the presence of chloride ions is likely to cause pitting corrosion to metals, and it will also accelerate the corrosion reaction; 3. Use deionized water for dispensing Deionized water is the best choice as the water for making aluminum hot rolling emulsion. The use of deionized water for dispensing water can fundamentally eliminate the possible impact of water quality on the emulsion, and the possible harm caused by ions in water will no longer exist. The direct harm of Ca2+, Mg2+, and the harm caused by the accumulation of Na+, Cl- plasma will be reduced to a minimum. Then, in the daily use of the emulsion, the metal ions entering the emulsion from the rolling of the sheet can be eliminated or alleviated through daily maintenance, so that the emulsion can be better and long-term for the stable rolling and rolling. Serve for good surface quality.
Aluminum hot rolling emulsion dosing water index and related dosing requirements 1. General testing items and index requirements for liquid dispensing water: Item Test result Hardness (ppm) 0 Conductivity (uS/cm) <10~20 pH 6-7 Chloride ion content (ppm) 0 In addition to certain requirements for the indicators of the water for dosing, certain requirements for the temperature and method of dosing water are also required when dosing aluminum hot-rolled emulsions. 2. The temperature of the dispensing water The temperature of the dispensing water should preferably be greater than 40 degrees, and the surface tension of the water is very large (73). It does not wet the oil on its interface, and it is difficult to emulsify the oil into the water, while the surface tension of the hot water is relatively small, which can It is because the viscosity of the oil becomes smaller, and the thermal motion is conducive to molecular motion and dispersion. In addition, the rational use of emulsifiers and the necessary circulation and other mechanical shear forces can make the oil droplets better dispersed into the water phase, forming a relatively It is a good oil-in-water emulsion and is well used in aluminum hot rolling production. 3. Liquid dispensing method As far as aluminum hot rolling is concerned, the emulsions used are mostly in a metastable state, and there are strict requirements for particle size distribution or stability of the emulsion. Therefore, there are certain requirements for the method of refueling and system circulation during dispensing. To prepare the aluminum hot rolling emulsion, the rolling oil needs to be added to the water. If the rolling oil has good emulsification, the emulsion can be directly added to the water and stirred to quickly form an emulsion in an emulsified state. However, when most rolling oils are prepared, it is necessary to add liquid before the circulating pump, and with the help of the mechanical shear force of the circulating pump, the oil-in-water emulsion with reasonable distribution of oil droplets can be formed, which is suitable for hot rolling production. The water phase in the emulsion for aluminum hot rolling occupies a large proportion, and the selected liquid preparation water plays a vital role in the stability of the emulsion and the production and quality of the strip. Deionized water is the best choice as the water for making aluminum hot rolling emulsion. The detection and control of liquid distribution water indicators and the selection of liquid distribution water temperature and liquid distribution method are also very beneficial to obtain good production and aluminum plate quality.
