Recently, covid 19 outbreak spreads in Shanghai, China. There are more than 25,000 new asymptomatic domestic infections every day. China is implementing a dynamic zero-out policy. A leading respiratory expert said the key to COVID-19 prevention and control is to minimize transmission and fatality rate. Omicron has a low case fatality rate but is highly transmissible and can still claim many lives in large outbreaks. "Total openness is not applicable in China. For China, we should keep to the dynamic zero-out and gradually open up."
However, "dynamic zero clearance" is not the pursuit of complete "zero infection". As the Novel Coronavirus has its own uniqueness and strong concealment, there may be no way to prevent the detection of cases at present, but rapid detection and prompt treatment must be carried out, as soon as one case is found, one case will be dealt with.
The situation in Shanghai is serious. As the financial center of China, Shanghai is a very important city, and the outbreak of the epidemic in Shanghai will put a great impact on China's economy. The current task is to contain the spread of the epidemic as soon as possible, to achieve social zero so that Shanghai's life and economy quickly return to normal.
As China plays an important role in the global supply chain, the outbreak will have a significant impact on the supply and prices of many ZnS powder.
Introduction to Zinc Sulfide ZnS Powder
Zinc sulfide is an inorganic compound with the chemical formula ZnS. It is a white or yellowish powder that darkens when exposed to sunlight. It is stable in dry air, and for a long time in humid air, it will gradually oxidize to zinc sulfate. It is usually produced by the action of hydrogen sulfide with zinc salt solution. Zinc sulfide has an excellent fluorescence effect and electroluminescence function. In particular, nano zinc sulfide has a unique photoelectric effect, and it presents many excellent properties in the fields of electricity, magnetism, optics, mechanics, and catalysis.
Physicochemical Properties of Zinc Sulfide ZnS Powder
The chemical bond between Zn and S of zinc sulfide tends to be covalent. The crystal has three different configurations: low-temperature type, that is, sphalerite structure, which is abundant in nature, colorless cubic crystal, the Zn, S coordination number is 4, and the relative density is 4.10. At 1020℃ it will transfer to high-temperature type; High-temperature type, that is, wurtzite structure, colorless hexagonal crystal, Zn, S coordination number are 4, the relative density is 3.98, melting point is about 1700℃. It is a zinc sulfide high-temperature stable structure; High-pressure type, namely sodium chloride structure, Zn, S coordination number are 6, the relative density is 5.21. There is also an aqueous compound ZnS·H2O, which is a white powder with a relative density of 3.98 and a melting point of 1049℃. Zinc sulfide is insoluble in water and dilute alkali, and insoluble in acetic acid, but soluble in low concentrations of strong acids such as hydrochloric acid, which release hydrogen sulfide. The solubility product of zinc sulfide is similar to the K1·K2 value of hydrosulphuric acid, so the following equilibrium exists in dilute acid:
It can be seen that in the highly acidic zinc salt solution, hydrogen sulfide gas cannot get zinc sulfide precipitation. In zinc salt solution, hydrogen sulfide gas is introduced, zinc sulfide precipitation can be obtained, but the precipitation is not complete. Using ammonium sulfide solution as precipitant, zinc ions in zinc salt solution can be precipitated into zinc sulfide completely, because ammonium sulfide solution is alkaline, the acidity of the system can be reduced. In industry, the above method should be used to isolate air. White zinc sulfide darkens when exposed to light and is easily oxidized to zinc sulfate in air. Zinc sulfide can be used as a white paint pigment by itself or in combination with zinc oxide. Pure zinc sulfide does not emit light. If trace manganese, copper, and silver are added to zinc sulfide crystals as activators, they can emit different colors of fluorescent light after light irradiation, which is called fluorescent powder and is used to make fluorescent screens and luminous paint. Zinc sulfide is also used in leather, enamel, rubber, dye, and other industries.
Zinc sulfide is corrosive and poisonous. It can irritate the skin. Operators should wear overalls and protective equipment. The workshop should be well ventilated.
|Zinc Sulfide ZnS Powder Properties|
|Other Names||ZnS powder, zinc sulphide|
|Appearance||white to off-white powder|
|Solubility in H2O||insoluble|
Preparation Methods of Zinc Sulfide ZnS Powder
Double decomposition method: Add zinc sulfate solution to the reactor, and slowly add ammonium sulfide for double decomposition reaction under stirring. Zinc sulfide and ammonium sulfate will be generated, then remove ammonium sulfate by filtration, and then by evaporation concentration, cooling crystallization, centrifugal separation, zinc sulfide will be produced
Applications of Zinc Sulfide ZnS Powder
1. Can be used as analytical reagents, phosphor matrix, photoconductor material; Or used for dyes, coatings, pigments, glass, curing oil manufacturing, etc.
2. Zinc sulfide is widely used in the production of infrared windows, fairing, and infrared optical elements. It has characteristics of high purity, insoluble in water, moderate density, and easy processing. Zinc sulfide has good refractive index uniformity and consistency. It has good image transmission performance in the band range of 8-12μm, but some of it begins to absorb after 10um. In the middle infrared band, the transmittance is higher, and the absorption and scattering are enhanced along with the shorter wavelength. Zinc sulfide has strong resistance to the harsh environment, and the high hardness and fracture strength are twice that of Zinc Selenide.
Tough front optics for zinc sulfide thermal imaging systems for infrared windows and thermal bands (8 to 14μm).
Single-crystal zinc sulfide is available but not common. The scattering is very low in the usual spectral range. It can be used as a high-power laser device under the condition of strictly controlling the bulk absorption and internal structural defects of the material and adopting the polishing technology with small damage degree and the coating technology with the highest optical quality.
Zinc sulfide oxidizes significantly at 300℃, exhibits plastic deformation at about 500℃, and dissociates at about 700℃. For safety reasons, zinc sulfide windows should not be used above 250°C in a normal atmosphere.
3. Used for optical coating target, X-ray screen, the luminescent dial by adding a trace amount of radium or neothorium salt, TV screen, and pigment for paint.
Main Supplier of Zinc Sulfide ZnS Powder
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) is a trusted global chemical material supplier & manufacturer with over 12-year-experience in providing super high-quality chemicals and Nanomaterials, including ZnS powder, nitride powder, graphite powder, zinc sulfide, calcium nitride, 3D printing powder, etc.
If you are looking for high-quality zinc sulfide powder, please feel free to contact us and send an inquiry. ([email protected])
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