How Are Gold coins Made?
The production of gold coins is a meticulous and intricate process that involves several critical steps, ensuring thecoins' purity, quality, and aesthetic appeal. Here's a detailed look at how gold coins are made.
1. Material selection
Gold coins are generally cast with high purity gold, with common purity of 99.9% and 99.99%. These gold raw materials need to be electrolytically refined to ensure that their purity meets the requirements.
2. Casting and molding
The purified gold raw material is put into Taeantech's vacuum ingot casting machine or vacuum continuous casting machine for melting, and the molten gold is cast into various specifications of blanks. These billets are mechanically milled to remove impurities and then cold-rolled under extremely demanding environmental conditions.
3. RollingIn a special finishing mill, the cold-rolled billet is rolled into a specular bright strip with a very small thickness tolerance, and the error is usually not more than 0.005 mm. 3. Stamping: the strip is stamped by the punch into a blank cake with the basic shape of the product. These billets must be guaranteed to obtain minimum burrs and optimum edges, and avoid any contamination and scratches.
4. Annealing and polishingAnnealing: Put the bad cake into the annealing furnace for high temperature softening treatment to improve its plasticity.
Polishing: The surface of the annealed cake is cleaned with a special cleaner, and surface impurities, oil and various oxides are removed. Then, a polishing machine is used to polish the billet so that its surface reaches a high flatness and finish.
5. Mold design and stampingMold design: According to the design draft, through fine engraving and modern precision equipment, the design intention is expressed on the mold. The design of the mold is a unique and important part of the coinage process, which determines the final appearance of the gold coin.
Embossing: In a purification chamber with air filtration, the cake is embossed using a mold. During the embossing process, the pattern and relief on the mold are precisely transferred to the billet. Since the impression is carried out in a very clean environment, any small dust can cause the coin to be scrapped. Internationally, the scrap rate of stamped coins is usually 10%, and for coins with large diameter and large mirror area, the scrap rate may be as high as 50%.
6. Quality inspection and packagingQuality check: Stamped finished gold coins are checked one by one to ensure their quality is up to standard. Any defective gold coins will be picked out and scrapped.
Packaging: Eligible gold coins are counted and packed into special boxes. In order to protect the original color of the gold coin, the surface of each gold coin will be protected to a certain extent, and placed in a plastic box, and then sealed with plastic film.
ConclusionThe production of gold coins is a blend of ancient traditions and modern technology, requiring immense precisionand attention to detail From refining the metal to the final inspection, each step is crucial in ensuring that thecoins meet the highest standards of purity, quality, and beauty, This meticulous process not only creates a valuablecommodity but also an artwork that reflects the craftsmanship and technological advancements of its time.
