Method for continuously producing nano tetrapod-like zinc oxide from secondary zinc slag

Abstract

The invention discloses a method for continuously producing nano tetrapod-like zinc oxide from secondary zinc slag. The method comprises a batching step: crushing and screening the secondary zinc slag, and weighing certain amount of secondary zinc slag as a raw material; a raw material melting, evaporating and oxidizing step: putting the weighed raw materials into a quartz crucible, putting the quartz crucible to the bottom of a crucible furnace, heating the crucible furnace until zinc in the raw materials is completely evaporated, stopping heat, leaving the residues at the bottom of the quartz crucible, controlling oxygen content in the crucible furnace, and enabling zinc to completely react with oxygen gas; a product collecting step: after the zinc completely reacts with the oxygen gas,taking out the quartz crucible, naturally cooling at the room temperature, scrapping the outer surface and the inner upper-layer surface of the quartz crucible to obtain white flocculent nano tetrapod-like zinc oxide crystal whisker. The method can utilize secondary zinc slag zinc-containing waste to produce the tetrapod-like zinc oxide crystal whisker which is stable in quality, is uniform in component, is single in shape and is fine in particle, so that the preparation cost of the nano tetrapod-like zinc oxide is reduced, and the secondary zinc slag is prevented from polluting the environment.

Description

technical field [0001] The invention relates to a production method of nano-tetraacicular zinc oxide, in particular to a method for continuously producing nano-tetraacicular zinc oxide by utilizing secondary zinc slag. Background technique [0002] In the prior art, the raw materials for producing nano-tetraacicular zinc oxide mainly include zinc powder, zinc ingot, zinc pellet, zinc sheet or high-purity zinc vapor; the preparation of zinc powder generally requires pre-oxidation of zinc powder to make the surface of zinc powder Form an oxide film with a certain thickness, the oxide film can inhibit the rapid evaporation of zinc during the heating process, and control the penetration of oxygen into the zinc powder to ensure the time required for the growth of four-needle zinc oxide whiskers; the pre-oxidation treatment of zinc powder directly The large-scale continuous production of nano-tetraacicular zinc oxide is limited; and high-purity raw materials such as zinc ingots, z...

AI Technical Summary

Problems solved by technology

The nanoparticle components obtained by the mechanical pulverization method are uneven and easy to agglomerate; the chemical reaction method is low in cost and simple in equipment due to the use of chemical reagents, but it cannot effectively control the morphology of zinc oxide whiskers and pollutes the environment; although the thermophysical method can obtain high Zinc oxide with high purity and high activity, but generally use vacuum conditions, which have high requirements for heating equipment, and the vacuum environment limits its industrial production; switching to inert gas protection can change the dependence on vacuum environment and equipment, but the inert gas introduced is also It will significantly increase the production cost, and, in the process of producing zinc oxide whiskers, the morphology of zinc oxide whiskers generally obtained is a mixture of different shapes, and it is difficult to produce single-morphology, nano-scale four-needle whiskers in large quantities. ZnO whiskers

[0004] In the hot-dip galvanizing production of iron and steel enterprises, a large amount of hot-dip galvanizing dross will be produced, in which the zinc content Zn>90 wt %; in order to realize the reuse of these hot-dip galvanizing dross, iron and steel enterprises usually purify the hot-dip galvanizing dross. Secondary zinc dross will be produced in the process, generally accounting for 20%~30% of the hot-dip galvanizing dross treatment volume, in which zinc content Zn>80wt%, iron content Fe<5 wt%, these secondary zinc dross will be sold at a low price Or directly discharged; since the content of elemental zinc in these secondary zinc slags is still above 80%, the existing treatment methods directly affect the efficient recycling of zinc resources, and direct discharge will seriously pollute the environment

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