How to Produce High-Quality Gold and Silver Granules
Gold and silver granules production guide
How to Produce High-Quality Gold and Silver Granules
Gold and silver granules are used in jewelry manufacturing, alloy preparation, silver refining, electronics, laboratory work, and later bullion casting. A good granulation process should produce clean, dry, uniform precious metal granules that are easy to weigh, remelt, store, and process.
High-quality gold and silver granules should be uniform, clean, dry, and easy to remelt for the next production step.
Watch gold and silver granules production videoSee the practical granulation process before choosing a metal granulator.What makes gold and silver granules high quality?
High-quality precious metal granules are not only small pieces of metal. For jewelry workshops, silver refineries, electronics users, and bullion casting factories, granule quality affects weighing accuracy, melting stability, oxidation control, and the final product surface.
- High purity: the raw gold or silver should be clean and suitable for the intended downstream process.
- Uniform size and shape: consistent granules melt more evenly and help reduce process variation.
- Smooth surface: a stable cooling process reduces rough surfaces and excessive oxidation.
- Dry and clean condition: granules should be dried before storage, remelting, alloying, or vacuum bar casting.
Uniform silver granules are easier to weigh, melt, and use in jewelry alloy preparation.
Step-by-step process for producing gold and silver granules
The production route is simple in principle: prepare clean raw material, melt it, control the molten metal flow, cool it rapidly, and dry the final granules. The difference between average granules and high-quality granules is process control.
Prepare material
Use clean gold, silver, alloy, ingot, bar, or suitable scrap. Remove moisture and visible contamination before melting.
Melt in crucible
Melt the metal in a graphite crucible with stable induction heating. Gold melts around 1064°C and silver around 961°C.
Control flow
The stopper rod, outlet hole, or graphite bottom plug controls molten metal flow and helps adjust granule size.
Rapid cooling
Molten metal enters clean water or a cooling chamber and solidifies quickly into granules with a smoother surface.
Dry and sort
Collect, dry, and sort the granules before packaging, refining, remelting, alloying, or bar casting.
Key process factors for stable silver granule production
Raw material purity
Impurities in silver scrap or mixed precious metal material can affect granule surface, melting behavior, and final use.
Melting temperature
Unstable melt temperature changes flow speed and droplet formation. Stable temperature control helps produce consistent granule size.
Outlet hole size
The graphite crucible plug-hole size or bottom plug die hole design is one of the main ways to control granule size.
Stopper rod control
A graphite stopper rod controls when molten metal starts and stops flowing, which improves safety and repeatability.
Cooling water condition
Clean water, proper water level, and stable temperature help reduce oxidation, sticking, and irregular granule shapes.
Drying before reuse
Wet silver granules can cause splashing during remelting. Always dry granules before storage or the next melting process.
Main structure of a gold and silver granulator
A precious metal granulator depends on several core parts. The graphite crucible and stopper rod are especially important because they control molten metal holding, sealing, and flow.
Graphite crucible
Holds and melts gold or silver. High-purity graphite reduces contamination and withstands high temperature.
Stopper rod system
Controls molten metal flow from the crucible to the granulation chamber for more repeatable granule production.
Granulation chamber
Receives molten droplets and cools them rapidly into gold or silver granules.
Control panel
Controls heating, temperature, flow timing, and working parameters for stable granulation.
Platform system
Uses a larger furnace, tundish, bottom plug die, cooling tank, and control system for high-output production.
Integrated system
Combines the melting furnace, crucible, stopper rod, chamber, cooling, and control panel in one compact unit.
Integrated granulator or platform-based granulator?
The original production target decides the machine type. A compact integrated silver granulator is easier for workshops, while a platform-based silver granulator is better for larger output and continuous production planning.
Integrated gold silver granulator
Best for jewelry workshops, small refineries, laboratories, and users who need a compact silver granulating machine with simple operation and lower installation space.
- All-in-one structure for easy installation.
- Suitable for flexible small and medium batch production.
- Uses graphite crucible and stopper rod to control molten metal flow.
Platform-based silver granulator
Best for industrial silver granule production, larger refining facilities, and factories that need higher output, stronger cooling, and modular equipment layout.
- Large furnace and high-capacity graphite crucible.
- Tundish and graphite bottom plug die support different hole sizes.
- Better for long working time and high-output production.
Comparison table for choosing a gold silver granulator
| Selection point | Integrated granulator | Platform-based granulator |
|---|---|---|
| Best use | Jewelry workshop, lab, small refinery, flexible batch production. | Large refinery, industrial silver processing, high-output precious metal granules. |
| Machine structure | Melting furnace, crucible, stopper rod, chamber, cooling, and control panel in one compact machine. | Separate platform with larger furnace, tundish, graphite bottom plug die, chamber, cooling tank, and control cabinet. |
| Granule size control | Controlled by melt temperature, outlet hole, stopper rod, and water cooling. | Controlled by temperature, tundish design, bottom plug hole size, water circulation, and process settings. |
| Factory space | Smaller footprint and easier installation. | Needs more space and better production layout. |
| Operation level | Simple and suitable for users starting granule production. | More suitable for experienced operators and industrial production planning. |
| Investment logic | Lower initial cost, good for moderate production demand. | Higher investment, stronger scalability, better for long-term output demand. |
Common production mistakes that affect granule quality
Wet raw material
Moisture can cause splashing during melting. Dry the material before charging the crucible.
Unstable temperature
Too low or too high temperature changes the molten metal flow and can produce irregular granules.
Wrong hole size
If the outlet hole or bottom plug die does not match the target granule size, the granules may be too large, too small, or inconsistent.
Poor cooling water
Dirty or overheated water can affect granule surface quality and cooling stability.
No drying step
Granules should be dried before storage or remelting. This is especially important before vacuum bar casting.
No regular cleaning
Clean the crucible outlet, stopper rod, chamber, and water system to keep the silver granulation process stable.
Core CDOCAST equipment for granule production
These four product links cover the main equipment customers usually compare when planning gold and silver granules production.
FAQ about how to produce silver granules
What is the best way to produce high-quality silver granules?
Use clean silver material, stable induction melting, correct graphite outlet hole size, controlled stopper rod flow, clean cooling water, and a drying process after collection.
How is silver granule size controlled?
Silver granule size is mainly controlled by melt temperature, outlet hole size, bottom plug die design, stopper rod opening, water condition, and the distance between molten metal outlet and cooling medium.
Can one granulator produce both gold and silver granules?
Many precious metal granulators can process both gold and silver, but the crucible, outlet, cleaning method, and temperature settings should be selected according to the material to avoid contamination and unstable granule quality.
Do silver granules need to be dried before remelting?
Yes. Silver granules should be dried before remelting, alloy preparation, refining, or vacuum bar casting. Wet granules can cause splashing and unstable melting.
Is an integrated silver granulator enough for a small jewelry factory?
For many jewelry workshops and small refining rooms, an integrated silver granulator is easier to install and operate. It is suitable for flexible batch production and limited factory space.
When should I choose a platform-based silver granulator?
Choose a platform-based silver granulator when daily output is high, production time is long, cooling demand is strong, or the factory needs a modular industrial silver granule production line.
Why does cooling water affect gold and silver granule quality?
Cooling water affects solidification speed, surface smoothness, oxidation, sticking, and granule shape. Clean and stable cooling water helps produce more uniform granules.
What information should I send before asking for a granulator quotation?
Send the material type, purity, target output per batch or per hour, expected granule size, working hours, available factory space, cooling condition, and downstream use.
Need help selecting a gold silver granulator?
Send your raw material type, target output, expected granule size, production method, and factory layout. CDOCAST can recommend an integrated or platform-based metal granulator according to your production route.