Zinc Dust
The most important processes for extracting gold with zinc dust are:
- Merrill-Crowe process: In this method, gold and silver are precipitated from the solution after leaching with zinc dust.
- In order to achieve effective gold precipitation, the dissolved oxygen must be extracted from the environment. This is necessary to prevent the gold from dissolving again. After the sedimentation phase, solid-liquid separation (filtration) is carried out. Other impurities must be removed from the cake by subjecting it to acid leaching or pyrooxidation. In the final stage, the gold or silver cake must be melted and the production of dore must be carried out.
As Carbontech, we offer you zinc dust chemicals for gold extraction. If required, we can supply you with chemicals with the properties you require.
Zinc dust is a grey-coloured, pure metal powder produced by the condensation of purified zinc vapours. The particle shape is spherical. Zinc powder consists of small pieces of zinc between 2.5μ and 9.0μ and is a metal used for various purposes. Some of the main uses of zinc powder are listed below.
1- In mining: In this method, the Merrill-Crowe process, gold and silver in solid form react with sodium cyanide to form gold-silver cyanide complexes. Zinc powder is then added to this solution at high pH to precipitate gold and silver, which is expressed by the following chemical reaction.
2Na[Ag(CN)2] + Zn > Na2Zn(CN)4 + 2Ag
2- In the paint industry: Since metals such as zinc and aluminium do not oxidise as easily as iron, they are used in paints and varnishes to prevent corrosion and oxidation of the material to which they are applied. Zinc-based paints can prevent steel surfaces from rusting and are widely used in industry. These paints can provide a hard-wearing coating for large structures such as offshore oil platforms, sea containers and other marine equipment. Zinc powder paint is also used for bridges.
3- Glass and ceramics: Zinc is used extensively as a flux in the manufacture of glass and ceramics, particularly in the production of frits and enamels for ceramic items. Zinc is also used for speciality glass applications such as heat-resistant glass, cookware and photochromic lenses.
4- Electronics: zinc oxide nanowires are used in LED manufacturing, semiconductor devices and even wearable textiles that can power digital devices. Compared to conventional methods, the materials and production process are cheaper and safer.
5- Fertilisation: Zinc deficiency is one of the most common micronutrient deficiencies in crops worldwide and leads to significant losses in crop production and quality. Zinc is considered an essential micronutrient for plants and grains. The use of zinc as an inorganic micronutrient fertiliser includes direct application to the soil to correct zinc deficiencies, root dipping and seed coating prior to transplanting, and the use of zinc as a component of foliar applications. These are used in particular for fruit trees and vines.
6- In plastics production: Zinc compounds offer various properties in the field of plastics:
- They impart fire-resistant properties to nylon fibres and moulds.
- They impart heat resistance and mechanical strength to acrylic composites.
- Zinc increases the dyeability of polyester fibres.
- Zinc compounds stabilise polyethylene against ageing and ultraviolet radiation. Applications include safety helmets, stadium seats, insulation, pallets, bags, fibres and filaments, agricultural and leisure equipment.
7- In battery production: Zinc is an important component in the manufacture of batteries. Zinc alkaline batteries (D, C, AA and AAA cells) are commonly used in radios, torches, cameras and toys. Button cell zinc-air batteries are often used in hearing aids, calculators and watches.