Let me briefly describe these two processes.
Lost wax casting method is to make a silver plate exactly like the jewelry to be made later, then weld the nozzle to remove the adhesive film, inject wax through the adhesive film, and then get a wax model exactly like the real thing. Plant many wax models on a wax column to form a wax tree, then seal the whole wax tree with gypsum and inject molten gold from a saliva. The wax has been oxidized into gaseous carbon dioxide and water at such a high temperature, thus retaining the whole gypsum mold.
The rule of die pressing is to carve out a steel female die, cut out gold nuggets with appropriate size, and then put them into a mold for high pressure, and use the ductility of gold for pressing. After that, some finishing and surface treatment are carried out to get the finished product.
From what I have described above, we know that the lost wax casting process is more complicated, but it can produce relatively three-dimensional jewelry. Anyway, jewelry processing industry is originally a labor-intensive industry.
Molding has a high degree of automation and high production efficiency, but it can only produce some solid and relatively flat ornaments, such as gold bars and coins, or some semi-finished ornaments of rings and bracelets.
In fact, there is another process for the processing of gold ornaments, called electroforming.
Using a similar electroplating method, gold is electroformed (plated) on the wax mold, which is much thicker than ordinary electroplating. Finally, the wax is released from the hole at the bottom by heating. This ornament retains the shape of a wax model. Although the electroforming layer is much thicker than electroplating, it is still very weak compared with ordinary gold jewelry, and can only be placed in a glass frame as an ornament. I believe you must have seen it in the gold shop. The gold electroformed by this process feels a little velvet, and some of it is polished with a polishing pen or agate knife before waxing.
As for the question of purity in the final analysis, both methods except electroforming can produce pure or impure ornaments, which has nothing to do with the process itself. Electroforming can only be used to electroform pure gold or pure silver or other non-alloy metals.
After knocking for a long time, I wrote it all by myself, without plagiarism.
I graduated from university with a thesis on the processing technology of gold ornaments. I hope the landlord will be satisfied.