Gold Refining

We had a wonderful morning at Presman Mastermelt;  learning about refining gold.

Starting in the basement melt room where the gold from, pawnbrokers, Jewellers and the dental gold is melted. First a very strong magnet was passed over the customer’s material, to separate any ferrous metal.  The material is carefully weighed and melted in a crucible with Borax, which helps the melt. The melt is regularly stirred to help it become more homogeneous and to ensue that a good test sample can be taken using a quartz ‘straw’. The technique is a bit like how a cocktail mixer takes a sample of a cocktail. Half the sample goes off to the laboratory for testing and half is retained, so that the whole process is traceable and can be double checked. The crucible of gold is then poured into a mould and the glassy Borax, which has drawn off any impurities and stones, remains on top. This gets broken away leaving the bar of gold.

No gold is wasted in the reclamation process, as there is also a facility to reclaim gold from items such as Polishing mops, old benches and workshop floor surfaces. These are all incinerated then the resultant ashes are sieved and ground to a very fine powder from which a blended sample is taken and tested chemically in the laboratory for the fines sog gold. Testing is very precise and if the multiple test results are not within 0.5%, then the whole testing process redone, thus ensuring the customer’s financial interests are protected. An interesting fact is that they reckon that around 98% of all jewellery in the market is made from recycled gold. The definition of recycled gold is anything coming from secondary sources and re-entering the supply chain. Whilst the gold recycling is done in house at Hatton Garden, they also recycle vast amounts of silver, which is processed in their Buxton facility because of the huge scale of the material.

Lastly, we were lucky enough to be led up to the penthouse floor. From here, not only can you observe St Pauls in the distance, but also the complex filtration plant on the Mastermelt roof. The system ensures that only steam is released into the atmosphere, thus being of no harm to the environment.

Many thanks to http://@garymastermelt for his time and patience with us.   Jason and GFW team