Chemical Composition and Properties

Zinc chloride (ZnCl2) is a white crystalline powder with a distinctive odor. It is formed by the reaction of zinc oxide with hydrochloric acid. The compound is highly soluble in water, and its solutions can conduct electricity due to the dissociation of ions. Zinc chloride exhibits hygroscopic behavior, readily absorbing moisture from the atmosphere.

PRODUCT DESCRIPTION

Zinc Chloride Powder color is white.  

Zinc chloride powder production process:

(1) Laboratory section

Before the raw material zinc ash participates in the reaction, a multi-element component chemical analysis is carried out to mainly detect the content of impurities such as sulfate and iron in the zinc ash raw material, which provides a basis for the addition of raw materials in the subsequent process section.

(2) Zinc replacement and sulfate radical removal section +

After the test process, the raw material zinc ash is put into the reaction tank, the dilute hydrochloric acid with a concentration of 16~18% is introduced from the storage tank tank to the reaction tank through a plastic pipe, and the zinc ash is mixed and stirred in the reaction tank, and the multi-component element The raw material zinc ash is transferred from the solid phase to the liquid phase, wherein most of the metal zinc in the raw material undergoes a displacement reaction with hydrochloric acid:

            Zn+2HCl→ZnCl₂+H₂↑

            Fe+2HCl→FeCl₂+H₂↑

While adding hydrochloric acid and zinc ash, add barium chloride, and use the characteristic that the resulting barium sulfate has a very small solubility product (1.07×10-10) to precipitate sulfate ions in the reaction tank:

Considering that the iron removal section needs to be carried out at a pH of about 6, there is an excessive amount of zinc ash in this reaction section, and the unreacted zinc ash is left in the reaction tank to continue to participate in the next reaction. The average amount of zinc ash used is 2469kg/d, the reusable zinc ash is 182.2kg/d, the amount of hydrochloric acid is about 16~18% dilute hydrochloric acid 14t/d, the hydrochloric acid converted into 100% is about 2290kg, and the natural volatilization loss in the reaction is 7.2 kg/d, the average dosage of barium chloride is 8kg/d.

(3)Press filter section

After the mixed liquid in the reaction tank flows through the filter cloth of the plate and frame filter press, a small amount of zinc chloride, residue, and barium sulfate stay on the filter cloth, and gradually accumulate on the filter cloth to form a filter mud cake. The filtrate part penetrates the filter cloth, and the filtered clear liquid is mainly a solution of zinc chloride, ferrous chloride and heavy metal ions. The filter mud cake of the filter press is zinc-containing waste residue, plus the solid residue regularly cleaned at the bottom of the reaction tank. The total amount of the two is about 80t/a, equivalent to about 320kg/d.

(4) Heating, oxidation and iron removal section

The filtered filtrate is supplied with heat from the kiln and heated to 40°C by the carbon plate. During this process, due to the full contact between the zinc liquid and the air, part of it has been oxidized by the oxygen in the air to precipitate, which is convenient for the next step to be removed faster. During this process, ferrous ions are discharged with water vapor.

Utilize the strong oxidizing property of potassium permanganate to oxidize ferrous ions into ferric iron. When the pH value is ≥6, the ferrous ions combine with hydroxide to form ferric hydroxide precipitate.

In this section, the average dosage of potassium permanganate is about 8kg/d.

(5) Filter press section

Similarly, after the mixed solution after removing ferrous ions passes through the filter cloth of the plate and frame filter press, the ferric hydroxide stays on the filter cloth, and the filtrate part penetrates the filter cloth to become a clear liquid without solids. The clear liquid is mainly a solution containing zinc chloride and heavy metal ions. The mud cake filtered by the filter press is iron slag, and the amount is 50t/a, equivalent to about 200kg/d.

(6) Heavy metal removal section

Metal zinc powder with a purity of 99% is added to the filtered filtrate to undergo a displacement reaction with the heavy metal ions in the filtrate, so that the heavy metal ions are converted from ionic to metallic and then removed by filtration.

(7) Heating, concentration, crushing, and packaging of finished products

The filtered solution contains high-purity liquid zinc chloride. Similarly, heat is supplied from the kiln, heated to 100°C by a carbon plate, and zinc chloride powder can be obtained by evaporating and concentrating. After crushing, the package is the finished product. During this process, water vapor is released.

Industrial Applications

Zinc chloride powder finds applications in numerous industrial sectors due to its corrosive and catalytic properties. It serves as a flux in metallurgy, aiding in the removal of impurities during metal processing. Additionally, it is used in soldering and galvanizing processes to improve the adherence of coatings to metal surfaces.

Preservation and Wood Treatment

In the realm of preservation, zinc chloride acts as a wood preservative. When infused into wood, it helps protect against decay, insect infestation, and fungal growth. This application is especially significant in the construction of outdoor structures and utility poles.

Dehydrating Agent

Zinc chloride's hygroscopic nature makes it an effective dehydrating agent. It is used in various applications, including the removal of water from solvents and gases. This property also makes it suitable for use in drying agents for laboratories and industrial processes.

Battery Electrolyte

Zinc chloride finds use as an electrolyte in certain types of batteries, including zinc-carbon and zinc-chloride batteries. Its ability to facilitate ion transfer between electrodes contributes to the battery's overall performance.

Flame Retardant and Smoke Suppressant

Zinc chloride powder is employed as a flame retardant and smoke suppressant in a range of materials, including textiles and plastics. When applied, it reduces the combustibility of these materials and minimizes smoke emission in case of fire.

Medical and Pharmaceutical Applications

In the medical field, zinc chloride is used in a variety of applications, such as wound care and antiseptics. It also serves as a coagulant in blood clotting studies and is a component in certain pharmaceutical preparations.

Safety Precautions

It's important to note that zinc chloride is corrosive and can cause irritation to the skin, eyes, and respiratory system. Proper handling, storage, and safety precautions should be observed when working with this compound.

Environmental Considerations

Zinc chloride poses environmental challenges due to its corrosive nature. Proper disposal methods are necessary to prevent contamination of soil and water sources.

In conclusion, zinc chloride powder is a versatile chemical compound with an array of applications across industries. From its role in metallurgy to wood preservation, dehydration, and flame retardancy, its unique properties make it an indispensable ingredient in various processes. As industries continue to innovate and seek solutions for diverse challenges, zinc chloride powder remains a reliable and multifaceted chemical compound.

FAQ

Q1: What is zinc chloride powder?

A1: Zinc chloride powder is a chemical compound with the formula ZnCl2. It is a white crystalline powder that is highly soluble in water. It is formed by the reaction of zinc oxide with hydrochloric acid.

Q2: What are the main uses of zinc chloride powder?

A2: Zinc chloride powder has various industrial applications. It is used as a flux in metallurgy to remove impurities during metal processing. It also serves as a wood preservative, a dehydrating agent, a battery electrolyte, a flame retardant, and a component in certain medical and pharmaceutical applications.

Q3: How is zinc chloride powder used as a wood preservative?

A3: Zinc chloride powder is infused into wood to protect it against decay, insect infestation, and fungal growth. This makes it particularly useful for outdoor structures and utility poles.

Q4: What is the role of zinc chloride powder as a dehydrating agent?

A4: Zinc chloride's hygroscopic nature makes it effective at removing water from solvents and gases. It is used in drying agents for laboratory and industrial processes.

Q5: In what types of batteries is zinc chloride powder used as an electrolyte?

A5: Zinc chloride powder is used as an electrolyte in certain types of batteries, such as zinc-carbon and zinc-chloride batteries. It facilitates the transfer of ions between electrodes, contributing to battery performance.

Q6: How does zinc chloride powder act as a flame retardant?

A6: Zinc chloride powder is employed as a flame retardant and smoke suppressant in materials like textiles and plastics. It reduces the combustibility of these materials and minimizes smoke emission in case of fire.

Q7: Are there any safety precautions when handling zinc chloride powder?

A7: Yes, zinc chloride powder is corrosive and can cause skin, eye, and respiratory irritation. Proper safety precautions, including protective equipment and proper handling techniques, should be followed when working with this compound.

Q8: What are the environmental considerations associated with zinc chloride powder?

A8: Zinc chloride can pose environmental challenges due to its corrosive nature. Proper disposal methods are necessary to prevent contamination of soil and water sources.

Q9: Can zinc chloride powder be used in medical and pharmaceutical applications?

A9: Yes, zinc chloride is used in medical and pharmaceutical applications, such as wound care, antiseptics, and blood clotting studies. It has various applications within these fields.