Jewelry shops provide services for remelting old jewelry, but many people prefer to do it themselves. Silver pieces accumulated at home can serve as raw material for creating your own pieces. For this purpose, it will be useful to know what the temperature of silver is meltingand what tools you'll need.
Silver as a metal: physical and chemical properties
The purest silver - is a malleable and fusible element in the precious metal group. This group includes gold, platinum, and five other platinum-grade metals.
All noble elements share the unique property of being inert when interacting with various air, liquid, and gas environments that lead to corrosion and oxidation. Lunar metal retains its natural luster when exposed to carbon dioxide. Under normal conditions, it reacts with sulfur to form silver sulfide.
In its pure form it is heavy, with a density of 10.5 g/cm3. It is slightly lighter than lead, but heavier than copper. It is able to retain geometric dimensions and surface properties when heated, while possessing a wide range of shape-shifting capabilities.
Among other things, the precious metal is famous for its disinfecting properties.
Melting and boiling point of silver: main factors
To melt the precious metal, it would take a temperature of 962 оC or 1234.15 Kelvin.
Boiling point - 2212 оC or 2485.15 Kelvin.
This is the point after which the liquid body begins to transition to the gaseous stage.
Table: Dependence of melting temperature on metal sample
The purity of the alloy directly affects the melting temperature. Low-purity compounds are melted at lower temperatures.
It is convenient to use the table to determine the melting point:
Which ligatures change their melting point
Ligatures are various chemical additives introduced into an alloy to improve its characteristics. The most common silver alloy is the union of silver and copper. This material is mainly used in jewelry, and its melting point decreases in proportion to its grade.
If platinum was used as an additive, the degree of melting would be 1000 оС.
The fusion of palladium and moon metal is often used in medicine and dentistry. The melting point of such a material is 1100. However, if Sample of the precious metal below 820, then the furnace temperature will decrease.
Technical silver Melts from 450 to 900 оC, it is usually 600-650, and the impurities are tin and cadmium.
Why melt silver
Many people are unaware that the precious metal is all around us. About 80% of the world's silver production comes from industry, and the rest from banks and jewelry.
Lunar metal is in radio componentsThe most important thing is that it is not only the most precious metal, but also batteries, contacts, capacitors, coins, cutlery, and jewelry. Even a computer or laptop of the average user contains about 1 gram of precious metal.
With the help of melting silver you can create your own analogue of bank bullion or unique dyeing. If you have accumulated a lot of silver items at home that can no longer be used, do not rush to throw them away.
Top 10 ways - how to melt silver: equipment, tools and materials for melting silver at home
Before you start smelting silver at home, you have to prepare thoroughly. The process will require a workplace, special equipment, and protective equipment. Safety requirements are mandatory when working with extreme temperatures.
So, to melt silver at home you will need:
Source of high temperature
The minimum melting point of silver starts at 780 degrees. Achieving this heating will help:
It is a device designed for heating to extremely high temperatures. The furnace is characterized by a muffle, a special shell that protects the material to be heated from the products of combustion.
The price of a muffle furnace for the home - from 10,000 rubles. It is quite economical in terms of power consumption. Speed of heating to working mode - from 5 minutes.
By the way, you can build an analogue of a muffle furnace with your own hands. Let's look at the step-by-step creation of the device.
- Sheet material from 2 millimeters thick can be used for the body of the cylindrical furnace. A coating of fire retardant paint will help protect the body from corrosion.
- Perlite is suitable as an insulating layer.
- The next step is to make the muffle. The refractory chamber is usually made of fireclay bricks. For a small furnace you will need about 6 bricks.
- The bricks are laid out in a row, after which it is necessary to make several notches for the wire. It will serve as a heating element. To connect the bricks, heat-resistant glue is suitable.
- The wire used as a heating element should be nichrome or fechral. These materials are capable of withstanding temperatures over 1000 degrees.
- The wire is run through the holes made inside the brick. Then you will need to drill holes through which the ends of the wire will come out.
- You need to use a cable to connect to the network.
A properly assembled homemade melter will last for many years and will be able to maintain the temperature necessary for melting.
Melt the silver in at home you can use an ordinary microwave oven.
This is a fairly safe way, the main thing is to set the maximum power in the microwave settings.
By the way, the microwave can melt gold from 585 pink and below, as well as aluminum, bronze, copper, melchior, and nesilver.
Gas stove in the kitchen
It is possible to melt the precious metal with an ordinary gas-fired stove if its purity corresponds to 875 sample and lower. This is due to the fact that the gas stove does not give a temperature above 900 оC, and bringing the precious metal to a state at which it could be cast would not be possible.
The melting point can be obtained with a gas or gasoline burner. The cost of such equipment - from 400 rubles.
Important: Material will not fuse if the torch is only pointed in one direction. It must be lifted with tongs during the process so that it can be fused from all sides.
Blowtorch is rarely but rarely used for this kind of work.
A vessel of refractory material along with the metal is placed in a thick lump of fireclay. This clay is designed for masonry work and is highly refractory. Soldering iron for the work must be powerful, able to heat up to 900 оС.
Chamotte clay is sold from 3 kilograms, and the cost starts at 50 rubles per kilogram.
Refractory laboratory crucible or asbestos melting mold
Smelting silver is impossible without a refractory vessel or crucible. A crucible is a vessel for heating, firing, and drying various materials. It usually has a conical or cylindrical shape. A crucible made of asbestos is one of its varieties.
Asbestos is a chemically resistant material that can withstand temperatures up to 1900 оС. If there is no crucible, you can take a spoon and cover it with asbestos sheets, and afterwards with flux.
You can buy crucibles in a store from 100 rubles apiece. Choose the ones that can withstand temperatures of 1000 degrees. The crucible usually lasts for 50 melts.
Before starting work, it is best to put asbestos under a fireproof container for additional protection. In this way fire hazards can be avoided.
You need to buy heat-resistant tongs or tweezers for the job. They are used to grip the crucible to pour the molten precious metal into the prepared mold, where it will harden.
The cost of heat-resistant tools - from 350 rubles.
An ordinary spoon can be used to make a mini-melting pot by covering it with asbestos sheets. Next, you need to cover the spoon with flux, which is sodium tetraborate. This is necessary so that the precious metal does not react with the air during melting.
Important: Sodium tetraborate is a drugstore borax. It not only prevents oxidation, but also helps the liquid base to flow over the rims of the crucible.
Cake is a mixture of melted metal and drills.
So that the precious metal can change from a solid to a liquid state faster, silver elements are broken into small pieces beforehand. Then they are mixed with borax in the ratio of 10 to 1 part of sodium tetraborate.
Pliers will be needed to break the silver elements into smaller pieces. Another tool also suitable for this purpose is pliers.
Silver alloys - are compounds of precious metal with various impurities. To extract the iron ligature particles from the material, it is necessary to use a magnet.
If the alloy is not cleaned in this way, the metal will heat unevenly in the future and it will take longer to transition to the liquid state.
Powerful step-down transformer with an output voltage of 25 V
The transformer is used as the main element of the melting device.
The electric furnace is connected to the transformer with copper wires. The thickness of the wires is at least 7 millimeters. The device should be placed on an insulated surface, away from flammable substances.
The furnace is heated for 5 to 10 minutes before starting work. After melting, the transformer is disconnected from the electric furnace.
It is advisable to buy jewelry electronic scales, they are available for order on the sites Ozon and Wildberries, the cost varies about 500 rubles.
Melting scrap silver on different devices at home
So, how to melt silver? The algorithm will be approximately the same for any method. The transition from one step to another should be carried out strictly in order.
- First, a melting pot is prepared, the role of which is a crucible or a spoon treated with apothecary borax.
- The silver parts are loaded into the smelter.
- The materials are now heated to a liquid state.
- The resulting liquid pour should be poured into a pre-prepared cast-iron mold.
Important: On the eve of the process, it is better to separate the precious metal by degree of purity. Material of different samples will have different furnace temperatures.
Melting silver on a gas burner
Knowing the temperature at which silver melts, you can begin the process. Casting at home involves the following steps:
- The precious metal must have a high degree of purity to work. The ideal grade is 999, 960, 925.
- Prepare a crucible of flame-retardant materials.
- Beforehand, get a mold for the casting. You can make it yourself or buy it in a special store.
- The metal, cleaned or broken into small particles, can begin to melt. The torch should be 3 to 5 centimeters away from the material.
- After the final transition of the precious metal into a liquid state, it must be poured into the prepared mold. This should be done as quickly as possible, but carefully. The base, ready for casting, resembles a drop of mercury. It should remain inside the mold until it is absolutely solidified.
- Once the precious metal has crystallized, it must be removed from the mold, then placed under a stream of ice water. If the silver does not separate from the mold, it is removed by hand after it has cooled.
Important: When using the torch, the flame must be watched carefully. It must be soft so that the flux does not fly off to the sides.
Melting in the microwave
This method is not only the safest but also the fastest. The power of the oven must be at least 700 watts.
For such melting you will need a muffle, a special container where the crucible will be placed. It is possible to make it yourself from an insulating board or buy it in a store. The main thing is that the muffle must fit inside the microwave oven without any obstacles.
- First, the glass plate must be removed from the microwave, and a heat-resistant support is placed in its place.
- The silvery parts are poured into the crucible. It should be placed inside the muffle, then in the furnace.
- The load of the microwave oven operation is set to full power. Usually it takes 15-40 minutes for the precious metal to become watery.
- The muffle can be removed from the furnace with work gloves, but the crucible - only with heat-resistant tongs.
Important: The shiny surface of the precious metal will tell you that the melting process can be stopped. If the surface is cloudy, it is worth continuing the procedure.
Precautions for melting operations
Casting processes require increased safety precautions. No flammable substances should be near the isolated work area. Do not skimp on protective equipment, be sure to purchase goggles with safety glass on the garter, an apron, gloves, and work clothes.
Clothing should cover the body completely, because even a drop of red-hot precious metal can burn an area of skin to the bone.
You can also purchase a fire extinguisher to avoid a fire.
Cleaning silver from impurities by yourself
The procedure for removing impurities is called refining. Refining can be used to purify:
- Scrap high grade products precious metal;
- Technical Silver;
- Waste from electrical cleaning;
The refining process should be carried out in a room with a powerful exhaust hood or outside. The air will be contaminated with substances that are harmful to humans.
To clear silver from impurities, you can put the material inside a liter jar and half fill it with nitric acid. The reaction will manifest itself with heat and a pronounced bitter smell.
It will be necessary to wait until the essence cools down completely. Then the salt solution is poured into the container. As the reaction proceeds, the precious metal chloride will settle to the bottom.
Now flowing water must be poured into the jar. When the sediment sinks to the bottom again, the surface water layer is drained off. The action is repeated several times until the essence is completely transparent.
Important: 250-350 ml of each reagent is needed per 100 g of material to be processed.
The electrolysis cleaning method is quite common. This refining is based on the peculiarities of the even electric current. The silver parts act as the anode and the silver plate as the cathode.
The electrolytic method will require:
- DC Transformer;
- Vessel with electrolyte (silver dissolved in nitric acid);
The formula for dissolving a precious metal with acid:
3Ag + 4HNO3 = 3AgNO3 + NO + 2H2O
The algorithm for further actions is as follows:
- The material to be cleaned is connected to the anode with clamps.
- A silver plate is connected to the cathode.
- A transformer with 2 W mains voltage is connected to a socket.
The positive cathode will attract the lunar metal, which needs to be fused afterwards.
The electrolysis method does not require cleansing and is suitable for the procedure at home.
Is it possible to mix silver of different samples for remelting?
Is it legal to melt silver at home in the kitchen?
Illegal extraction can lead to an administrative fine. Article 15.44 of the CAO states: the amount of the fine will be one or one and a half times the value of the materials that are the subject of the offense.
If you try to sell the bullion to buyers, you may be criminally liable.
Which grade of silver is the easiest to melt?
Of the most common markings, the lowest melting range has 800 - from 780 оC and above.
Is it possible to melt down silver into fine jewelry at home?
Video: melting silver at home with different devices
It should be remembered that such activities are subject to mandatory licensing. IEs and legal entities have the right to buy and process the remains of precious metals with a certificate from the Assay Office.