Zinc oxide rotary kiln production line：
Zinc oxide is a fine white or slightly yellow powder that is odorless and tasteless. When heated, it gradually turns into light yellow or lemon yellow. After cooling, the yellow color fades and turns white. It sublimates at 1800 ℃. Mainly used in industries such as rubber, coatings, enamel, pharmaceuticals, printing, fibers, etc. The tire and rubber industry is the industry with the highest usage, accounting for over 60% of the weight of the zinc oxide industry. The main component of secondary zinc oxide is ZnO, with a grade generally ranging from 45-65%. The term 'secondary' refers to low grade.
The calcination of secondary zinc oxide in a rotary kiln is carried out using zinc containing raw materials such as steel plant flue ash, iron slag, non-ferrous smelter flue ash, blast furnace ash, and zinc ash (with zinc content of 8-20%, lead content of 2-8%, arsenic content of less than 1%, sulfur content of less than 1.5%, and silver content of more than 20g/t). After being pulverized by ball mills, Raymond mills, and other grinding equipment, coal powder balls are added (with a coal powder ratio of 100:40). Zinc oxide (content of Zn45-60%, Pb5-8%) is obtained by high-temperature (1000-1100 ℃) oxidation roasting of zinc steam and hot air oxidation in a rotary kiln. After calcination in a rotary kiln, the slag (lead 0.3-0.5%, zinc 1-2%, iron content 20-30%) is sold in cement plants or magnetic separation iron.
Equipment Introduction：
The main components of the entire equipment set are:
1.Feeding section
The raw materials are mixed by a loader, and the mixed materials are fed into a silo. They are then quantitatively fed to a belt conveyor through a disc feeder at the bottom of the silo, and finally calcined in a kiln through the belt conveyor.
2.Rotary kiln system
It mainly consists of kiln body and combustion system. After entering the kiln, the material flows in reverse through a 5% slope, and the temperature inside the kiln is controlled between 750-1200 ℃. The thermal separation flow rate is 3-4m/s, and the average residence time of the material in the kiln is 1.8 hours. The rotation speed is 90s/rpm, and the recovery rate reaches over 98%.
3.Slag water system
The residue of the calcined material is directly discharged into the water tank, and after being cooled by water, it is grabbed by the slag catcher and transported to the storage warehouse for crushing and storage.
4.Dust collection system
The high-temperature (750 ℃) gas containing various partial oxides and dust sent from the rotary kiln is subjected to the first separation, heat dissipation, and further oxidation in the settling chamber; The oxide and some dust brought by the cooled gas (temperature 300-400 ℃), which has a higher density than the oxide, are separated and cooled for the second time (temperature<160 ℃) through more than 11 sets of multi tube coolers; The incoming gas at around 160 ° C, carrying a high concentration of oxides and dust, is separated and cooled by pulse method. The dust falls into the ash hopper, and the gas enters the desulfurization tower, where the temperature drops below 60 ° C. The sulfur dioxide gas and other gases entering the desulfurization tower flow upward from the bottom of the tower, while the alkaline solution flows downward in a three-stage mist from top to bottom, and moves upward through the direction change and deceleration of the three-stage hollow sphere to achieve acid-base neutralization. The final sulfur content of the discharged gas should not exceed 400 milligrams. After acid-base neutralization, calcium sulfite precipitate will be produced, and the water slag will be separated and reused by a filter press. Calcium sulfite is discharged as waste residue.
Parameters of Zinc Oxide Rotary Kiln：
Process Flow Diagram:
