The production of zinc involves several key steps, beginning with the extraction of zinc ore, typically zinc blende (zinc sulfide) or calamine (zinc carbonate). The ore is first concentrated using the froth flotation process, where the ore is crushed, ground into fine particles, and mixed with water and reagents. This process makes the zinc sulfide particles hydrophobic, allowing them to attach to air bubbles and float to the surface, where they are skimmed off for further processing[1][2].
The concentrated ore then undergoes roasting, where it is heated in a fluidized-bed roaster or other types of roasters to high temperatures (around 950°C) to convert the zinc sulfide into zinc oxide. This zinc oxide is then leached with sulfuric acid to produce a zinc sulfate solution, which is purified to remove impurities such as lead, copper, and cadmium. The purified solution is then subjected to electrolysis, where an electric current is passed through the solution, causing zinc ions to be deposited onto aluminum cathodes. After approximately 22 hours, the zinc sheets are stripped from the cathodes and melted in furnaces to produce molten zinc, which is then cast into various shapes and sizes, such as slabs, ingots, and blocks[3][4].
Zinc is an essential trace element that is generally safe for human consumption when taken in recommended amounts. The Recommended Dietary Allowances (RDAs) for zinc are 11 mg/day for men and 8 mg/day for women, with higher recommendations for pregnant and lactating women[1][2]. When consumed orally, zinc is likely safe up to 40 mg daily, but higher doses can lead to decreased copper absorption, and very high doses (10-30 grams) can be fatal. Excessive zinc intake can cause stomach pain, vomiting, and other health issues, including anemia, pancreas damage, and decreased HDL cholesterol levels over prolonged periods[3][1][2].
The safety of zinc in food and beverages can be compromised by several contamination risks. Heavy metal contamination, such as lead and other metals, can occur in soil and subsequently in crops, especially when excessive fertilizers are used. This can lead to elevated zinc and other heavy metal levels in food, potentially causing liver damage and gastrointestinal diseases if ingested in excess[4]. Additionally, heavy pesticide use in agricultural practices can contaminate crops, although zinc itself is not typically associated with pesticide contamination. Pathogen risks are also a concern if the food is not handled or cooked properly, but this is more general to food safety rather than specific to zinc. Furthermore, zinc can mitigate the uptake of heavy metals in plants, but improper agricultural practices can still result in contaminated food products[5]. Therefore, ensuring proper agricultural practices, fertilizer use, and food handling is crucial to minimize these risks.
Hundreds of ingredients are entering the US food supply every year. Not to mention, the hundreds of tainted products with unlabled toxic contaminiants. Join so you can shop with ease of mind.