Zinc oxide (another name is zinc oxide) is an amphoteric oxide, a crystalline colorless powder, yellowing upon gradual heating and sublimating at 1800 degrees. Insoluble in water. The oxidation state of zinc in this compound is 2. The chemical formula of ZnO. This substance is important for humanity. It has a multifaceted effect on the human body.
Zinc oxide: physical properties
- Thermal conductivity is 54 W / (m * K).
- It is a semiconductor with a band width of 3.3 eV.
Chemical properties of zinc oxide
- Reacts with acids. In this case, salts are formed.
- Reacts with alkalis with the formation of tetra-, tri- and hexahydroxycincates.
- This substance is soluble in ammonia aqueous solution. In this case, complex ammonia is formed.
- When fused with oxides and alkalis, zinc oxide forms zincates.
- When fused with silicon and boron oxides, zinc oxide forms silicates and vitreous sides.
How to get zinc oxide (ZnO)
Zinc oxide can be obtained in several ways:
- from the natural mineral zincite;
- by burning vapors of zinc (Zn) in oxygen (O) - this is the so-called "French process";
- by thermal decomposition of the following compounds: Zn (OH) 2 hydroxide, Zn acetate (CH3COO) 2, Zn nitrate (NO3), ZnCO3 carbonate;
- during oxidative roasting of ZnS (zinc sulfide);
- in hydrothermal synthesis;
- by extracting sludge and dust from metallurgical plants. Of particular importance are those plants that specialize in scrap metal containing a significant proportion of galvanized iron.
The use of zinc oxide
Zinc oxide is used in the manufacture of rubber, paper, some plastics, rubber products, artificial leather, electric cables, glass, ceramics, cosmetics (sun creams, various cosmetic procedures) and perfumes. It is used as an activator of vulcanization of various rubbers, a catalyst for the synthesis of organic matter - methanol, a vulcanizing agent of chloroprene rubbers, pigment and filler in production. Previously, zinc oxide was needed as a white pigment in the production of enamels and paints, but now it is completely replaced by TiO2 (titanium dioxide is non-toxic). Zinc oxide was also widely used in the paint and varnish, tire and oil refining industries.
Zinc oxide was widely used in medicine and pharmaceuticals (Zinc Ointment, Sudokrem, and Lassara Pasta preparations). It is used as part of antiseptic ointments, in the form of powders. In practice, it is used to create bactericidal ceilings and coatings in hospitals, self-cleaning surfaces. Using zinc oxide, toothpastes and cements for therapeutic dentistry are produced . Previously used on an industrial scale for photocatalytic water treatment.
Also, the substance we are considering is used in the manufacture of paints and glasses based on liquid glass, as one of the components of the rust remover and as an additive to animal feed. In addition, the powder of this substance is a promising material as a working medium for powder lasers. Based on zinc oxide, a light blue of a blue color was created. And some nanostructures (for example, thin films) based on this substance can be used as biological or gas sensitive sensors.
What effect does zinc oxide have on humans?
This chemical compound is low toxic. In the air of working premises MPC should be no more than 6 milligrams per cubic meter. Zinc oxide dust can be formed during the firing of brass products. When working with zinc oxide, it is necessary to prevent contact with the eyes. Zinc oxide medications are recommended only as directed by a doctor.