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CN-121990603-A - Preparation method of high Wen Jingmian isolation type cold-welding-resistant indirect zinc oxide and product thereof

CN121990603ACN 121990603 ACN121990603 ACN 121990603ACN-121990603-A

Abstract

The invention discloses a preparation method of high Wen Jingmian isolation type zinc oxide by a cold welding indirect method and a product thereof, belonging to the technical field of inorganic powder preparation. The method is characterized in that the temperature of the air flow is controlled to be 350-550 ℃ in a high-temperature flue after an outlet of an oxidation chamber for producing zinc oxide by an indirect method and before dust collection by a cloth bag, and inorganic modifier precursors such as silicate, borate or zirconium salt are continuously introduced into the high-temperature flue to form aerosol. The modifier is decomposed or reacted in situ at high temperature to form high temperature resistant inorganic isolating layer deposited on the surface of zinc oxide crystal grain, and the isolating layer can separate the crystal grains before cold welding fusion to block hard agglomeration. And collecting dust and cooling by a cloth bag to obtain a high-dispersivity zinc oxide product. The method has the advantages of simple process, easy integration with the existing production line, no high-temperature hard agglomeration, high looseness, good dispersibility, no influence on the chemical properties of the zinc oxide body, and suitability for continuous clean production of high-end zinc oxide.

Inventors

  • ZHANG LINA
  • FANG CHUNPING

Assignees

  • 江苏爱特恩高分子材料有限公司

Dates

Publication Date
20260508
Application Date
20260308

Claims (9)

  1. 1. A preparation method of high Wen Jingmian isolation type zinc oxide by cold welding prevention indirect method is characterized by comprising the following steps of controlling the air flow temperature to be 350-550 ℃ in a high-temperature flue between an oxidation chamber outlet and a cloth bag dust collector in the production flow of the indirect zinc oxide, continuously introducing an inorganic modifier precursor into the high-temperature flue to enable the inorganic modifier precursor to form aerosol in the air flow, enabling the inorganic modifier precursor to react in situ on the surface of zinc oxide crystal grains at the high temperature to form an inorganic isolation layer so as to isolate high Wen Lenghan among crystal grains, and collecting dust through a cloth bag and cooling to obtain a zinc oxide product.
  2. 2. The method of claim 1, wherein the inorganic modifier precursor is selected from one or more of silicate compounds, borate compounds, thermally decomposable zirconium salts, zirconium phosphate precursors, and combinations thereof.
  3. 3. The method of claim 1, wherein the silicate compound is methyl orthosilicate, ethyl orthosilicate or ethyl polysilicate, the borate compound is trimethyl borate or triethyl borate, and the thermally decomposable zirconium salt is zirconium oxychloride, zirconium nitrate or ammonium zirconium carbonate.
  4. 4. The method of claim 1, wherein the inorganic modifier precursor is introduced into the high temperature flue in the form of a solution or suspension by atomization or in the form of a gas by a carrier gas.
  5. 5. The method according to claim 1, wherein the total amount of the inorganic modifier precursor is 0.1 to 0.7wt% based on the mass of the active ingredient of the inorganic barrier layer which is finally formed on the zinc oxide surface, based on the mass of the zinc oxide product.
  6. 6. The method of claim 1, wherein the temperature of the gas stream in the high temperature flue is controlled to be 380 ℃ to 500 ℃.
  7. 7. The high-bulk zinc oxide product according to any one of claims 1 to 6, wherein the primary grain surfaces of the zinc oxide product are coated with an inorganic isolation layer, and the inter-grain hard agglomerates formed by the high Wen Lenghan are absent.
  8. 8. The zinc oxide product of claim 7, wherein the inorganic barrier layer comprises one or more of silicon oxide, boron oxide, zirconium phosphate.
  9. 9. The zinc oxide product of claim 7, wherein the zinc oxide product has a lower tap density and higher dispersibility than an in-situ zinc oxide without high temperature isolation treatment.

Description

Preparation method of high Wen Jingmian isolation type cold-welding-resistant indirect zinc oxide and product thereof Technical Field The invention belongs to the technical field of inorganic powder material preparation and surface modification, and particularly relates to a preparation method for carrying out in-situ crystal face isolation on indirect zinc oxide under a high-temperature condition so as to inhibit crystal grain cold welding and prevent hard agglomeration, and a zinc oxide product with high looseness and excellent dispersibility. Background The indirect zinc oxide is an important industrial raw material and is widely applied to the fields of rubber, ceramics, paint, electronics, chemical industry and the like. Conventional production processes thereof typically include melting, evaporating, oxidizing, and subsequent cooling and collection of metallic zinc. At the outlet stage of the oxidation furnace (chamber), the primary zinc oxide grains are produced in a high temperature state (typically up to 300-600 ℃). At this high temperature, the highly active zinc oxide grains are extremely susceptible to cold welding or sintering phenomena through diffusion and rearrangement of surface atoms during the mutual collision and contact processes, thereby forming strong, chemically bonded hard agglomerates. The hard aggregate is difficult to break up by conventional mechanical force in the subsequent working procedure, and can obviously reduce the specific surface area of the final product, influence the dispersibility, uniformity and reactivity of the final product in an application system and finally damage the service performance of the final product. In order to solve the problem of powder agglomeration, the prior art generally carries out physical or chemical modification on the collected zinc oxide at normal temperature, such as adding a surfactant, a coupling agent or carrying out mechanical grinding. However, these methods are "post-processing" and do not interfere with or prevent the cold welding process of the grains that has already occurred in the high temperature zone at the outlet of the oxidizing furnace. Thus, hard agglomerates have formed and subsequent modifications tend to be performed only on their surfaces for a second time, with limited effectiveness. In addition, most organic modifiers are difficult to resist high temperature and can be decomposed and disabled in a high temperature area, and inorganic high temperature modification is seldom applied to source inhibition of a zinc oxide high temperature synthesis stage in a targeted manner. Therefore, a novel preparation method capable of effectively isolating crystal grains from sources and preventing cold welding hard agglomeration from forming at the initial high-temperature stage of zinc oxide formation is developed, and the method has important practical significance and technical value for improving the product quality of indirect zinc oxide and expanding the high-end application of the indirect zinc oxide. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art and providing a preparation method of zinc oxide by an indirect method of 'high Wen Jingmian isolation type cold welding prevention'. According to the method, a specific inorganic modifier is introduced in situ in a high-temperature section of an outlet of an oxidation chamber, so that a high-temperature resistant physical isolation layer is formed on the surface of a new zinc oxide crystal grain, and effective isolation is realized before cold welding fusion of the crystal grain, so that the generation of hard aggregates is fundamentally stopped. The technical scheme adopted by the invention is as follows: the preparation method of the high Wen Jingmian isolation type cold-welding-resistant indirect zinc oxide is characterized by comprising the following steps of: s1, controlling the reaction temperature and the reaction area, wherein in the indirect zinc oxide production flow, the reaction area is limited in a high-temperature flue after an outlet of an oxidation chamber and before a bag dust collector. The temperature of the air flow in the region is precisely regulated and stabilized between 350 ℃ and 550 ℃. This temperature range is a critical window period that ensures that the modifier reacts effectively and that the zinc oxide crystallites have not yet undergone severe cold welding. S2, introducing an inorganic modifier, namely continuously and uniformly introducing a pre-prepared inorganic modifier precursor solution or suspension into the high-temperature flue in the step S1 in a mode of carrying by an atomizing nozzle or carrier gas, so that aerosol is rapidly formed in high-temperature airflow. S3, forming a crystal face isolation layer in situ, namely, performing thermal decomposition and hydrolysis (utilizing trace water vapor in flue gas) or reacting with airflow components rapidly in the high-