The treatment process of regenerated zinc in China is divided into two methods: fire separation method and wet method. Wherein the high zinc content of the waste processing method of metal materials having a reducing heteroaryl distillation, wet, liquation melting aluminum method. The treatment of zinc dust with low zinc content, such as rotary kiln, flat kiln and other processes, first produces zinc oxide, and zinc ingots can be obtained directly.
1. Treatment of waste materials with high zinc content
The distillation method and the wet method are currently used for the recovery process of zinc slag, zinc ash, etc., which have a high zinc content, and zinc ingots can be obtained directly.
(1) Treatment of zinc-rich waste by horizontal tank distillation
This method is relatively simple in production process, does not require a lot of electromechanical equipment, has less capital investment and lower cost. It is still used by some small-scale regenerative zinc smelters in China to process zinc-rich waste, such as hot-dip galvanized ash, zinc slag and coarse Zinc ingots, scraps, etc.
When the raw material for zinc smelting in the horizontal tank is zinc slag, the zinc recovery rate is 80%-85%, and if it is zinc ash, it is only 40%-60%. The zinc obtained from the horizontal tank zinc smelting is not high, generally only reach No. 4 or No. 5 zinc, even the outer zinc. In order to obtain high quality regenerated zinc, it needs to be rectified and refined.
(2) Vacuum distillation
The principle of this method is to use zinc vapor and other metals in the zinc slag to achieve the purpose of separating zinc and impurities. The method can only deal with hot-dip galvanizing slag, which has the advantages of higher evaporation rate and higher metal recovery rate at lower temperature, selective recovery of components in the material, and avoidance of oxidation and product. Other pollution, the purity can reach 99.8% ~ 99.9%, the recovery rate can reach more than 85%. The unvaporized zinc in the slag can be returned to the distillation after simple sorting, so the total recovery rate can reach over 98%, and the equipment is simple, the operation is simple, and the processing cost is lower than the conventional flat tank regeneration process. However, the equipment investment of this law is large, and the promotion is limited. It is used in some large galvanized steel plants.
(3) Wet process
The wet process can be divided into two processes: soluble anode electrolysis and leaching-purification-electrodeposition. The soluble anodic electrolysis process is suitable for treating zinc slag, while the leaching-purification-electrodeposition process is suitable for treating zinc ash. Both processes use an aqueous solution of sulfuric acid and zinc sulfate as the electrolyte.
In the zinc smelting industry, wet zinc smelting is the main technical development direction. The advantage of the wet process is that the zinc recovery rate is high, about 20% higher than the traditional fire method, which is convenient for mechanization, automation, process wastewater, Less waste residue and less environmental pollution.
Second, the treatment of zinc dust in steel plants
And scrap iron in a blast furnace to recover zinc smelting process, iron ore and steel galvanized zinc layer will volatilize gaseous, with the flue gas is collected into the dust collection system down. This kind of soot, depending on the source of raw materials, varies in the amount of zinc. These zinc-containing soots are mostly produced by rotary kiln, open hearth and other processes to produce zinc oxide (50% zinc). Then sold some zinc oxide plants to further produce high-purity zinc oxide.With more than 30 years customers` actual operation and technology improvement, 1500mm two/three/five layers fully automatic stretch film machine is mature and cost-effective, some whole production line adopt melt metering pump technology and high precision pressure sensor system, which can stably and effective to control the pressure. It will highly improves film horizontal and vertical`s tension strength and anti-puncture resistance and make the film meeting the high requirement for machine packing film. The cooling roller adopts big diameter design and special double-decker runner, greatly improving the cooling effect of high-speed production to guarantee good uniformity of cooling roll surface temperature. The film produced by this machine has good shrinking memory function and self-sticky, which can be widely used in wrapping of palletized goods. It`s good substitute for hot shrinking packing film during transportation.
*Related Products:pe casting film machine,pe cling film machine,pe protective film machinery.
Machine Pictures:
Plastic melt metering pump is more and more important in extrusion process, especially in high-end products industries, such as high quality sheets, pipes, BOPP, optical cable.
Installing the melt metering pump in the cast stretch film unit, which can keep the production constantly and efficiency. The pump can improve the product quality, stable the production and decrease the energy consume.
The housing is made of chromium-nickel alloy or nickel-base alloy, titanium alloy. The gear is made of quenching chromium steel, other metal materials are also applicable. Bearing is made of graphite NIAG, zirconium oxide or quench tool steel.
Advantages:
FAST AND STABLE FLOW SUPPLY
Eliminated the extruder`s pulsation wave. Improve the product quality, decrease the defective rate, and decrease the waste, which can save 2% material and 25% of the unit power consumption.
STABLE AND EFFICIENCY PRESSURE CONTROL
The melt pump can provide a stable pressure, which short the discharge time obviously and make the production effectively.
INCREASE THE EXTRUDER OUTPUT AND THE MACHINE LIFE
It has been found that after install the melt pump, the max pressure wave value is the pressure after pump. Which can make the inner pressure of the extruder decrease, the melt shear strength decrease, the temperature curve gently, and restrain the temperature rising. Also the melt pump can avoid the damage to the extruder from the high pressure.
Produced Films
1500mm stretch film machine unit
1500MM Black Stretch Film Machine Unit,1500MM Hand Stretch Film Machine Unit,1500MM Plastic Stretch Film Machine Unit,1500MM Packaging Stretch Film Machine Unit
CHANGLONGXING SCIENCE & TECHNOLOGY (SHENZHEN) CO.,LTD , https://www.clxmachinery.com