Gold melting and smelting are metallurgical procedures you can use to concentrate and recover gold. However, most people tend to confuse the two.
So, let’s begin by defining each process.
Melting is the process of changing gold from solid to liquid state. These could be scrap gold such as jewelry, coins or fittings.
On the other hand, smelting is a chemical reaction that reduces metal oxides (gold ore) to pure gold and an oxide waste (slug). That is, you can use it to obtain pure gold.
As you can realize from the two definitions, the main difference between gold smelting and gold melting are:
1. The nature of the end product based on quality
2. The process involved in getting the end product
To get better insights on the two processes, I will discuss them separately, then wrap it up with a succinct conclusion.
First, gold smelting require specialized equipment – furnace, chemicals, mold and source of heat. As I stated earlier, this process aims to produce pure gold (free from impurities). To achieve this, you need to:
- Pulverize gold material into fine pieces
- Heat the furnace to temperature between 1150 and 1450 ̊C
- Place gold ore to burn off impurities
- Introduce chemicals to separate gold from other metals. The main chemical to use in the gold smelting process are potassium cyanide and mercury. NOTE: This is a key procedure that differentiates smelting from melting. This chemical will cause melted gold to coagulate, forming pure nuggets.
- Also, in gold smelting, you can use flux. It reduces smelting point and captures metal oxides.
With these, you will remain with pure gold that you can heat and pour into mold to form pure ingots. Remember, these ingots come in different shapes and sizes.
Again, the effectiveness of this process will depend on the type of gold smelting furnace. Also, remember to smelt gold in a well-ventilated area. Some of impurities such as sulfur produce pungent smell.
Gold melting process
The process here remains almost the same. Remember, your main objective will be to convert the pure gold you have into a liquid form and may be mold them into appropriate shapes.
It is a common process you can use to recycle old gold materials such as rings, jewelry or parts. The process involves:
- Cut material into small pieces
- Heat crucible or furnace to desired temperature (1150 to 1450 ̊C)
- Let all gold melt and pour it into desired mold.
NOTE: For this process, we are only interested in changing the state of the solid gold material.
Well, you should realize that:
- Both processes require heating gold to melting point
- When gold smelting requires the use of chemicals.
- Gold smelting is used to extract gold from its ores. Thus, a common process in the gold mining industry.
- Smelting is more laborious than melting due to the processes involved.
- Gold smelting is slightly expensive compared to gold melting.
In summary, gold melting is a perfect choice for recycling used gold products. On the other hand, gold smelting is adopted for extracting pure gold from the ore.