The issue of recycling old household appliances often comes down not only to freeing up useful space in the kitchen, but also to the opportunity to receive material benefits from disposing of non-ferrous metals. The compressor, which is the heart of any refrigerator, is a sealed unit, inside of which a significant supply of expensive raw materials is hidden. It is electric motor that forms the basis of this unit and contains up to 90% of all valuable metal in the unit.
The process of extracting copper requires not only physical strength, but also an understanding of the internal structure of the mechanism. Standard piston compressor is sealed, which eliminates the possibility of simple disassembly by unscrewing the bolts, as happens in open models of internal combustion engines. You will be faced with a non-separable housing, welded or soldered at the factory.
Before taking active steps, it is necessary to assess the economic feasibility and risks. Time costs, metal cutting consumables, and eye and hand safety must be considered in advance. Next, we will look in detail at how to properly prepare the workplace and what tools are needed for effective processing.
Assessing the contents and preparing the workplace
The first stage is visual inspection and weighing. The weight of the compressor varies depending on the power of the refrigerator, usually ranging from 10 to 25 kilograms. However, the total weight does not say much, since most of the mass is made up of a steel shell (housing) and oil. Copper yield is on average 10-15% of the total mass, that is, from one unit you can get about 1.5–2.5 kg of pure metal.
⚠️ Attention: Before starting work, make sure that the compressor is completely disconnected from the electrical network. Even if the wires are cut, there may be residual charge inside the start relay capacitors.
The choice of cutting location is critical. The process is accompanied by the formation of metal shavings, oil splashes and possible sparking. Work outdoors or in a well-ventilated garage with a concrete floor. The use of angle grinder (grinder) requires a stable surface to prevent the tool from slipping.
Preparation of tools includes the presence of a powerful grinders discs for metal with a thickness of at least 2.5 mm, since thin discs can jam in the thick steel of the housing. You will also need pliers, a hammer, a chisel, a set of screwdrivers and a container for draining technical oil. Don't forget about personal protective equipment: glasses, gloves and a respirator.
Draining the oil and dismantling the external elements
Inside the sealed casing there is compressor oilwhich must be drained before cutting the metal. This will not only prevent contamination of the work area, but will also protect against aggressive liquids coming into contact with the skin or mucous membranes. The oil may have a specific odor and be colored dark due to wear products.
To drain, you need to turn the compressor over and find the drainage holes or carefully cut off one of the copper tubes at the bottom. Often the oil drains slowly, so you should place a wide container and wait 15-20 minutes. Some experts recommend shaking the unit slightly to speed up the process of draining the viscous liquid from the internal cavities.
After removing the oil, we proceed to dismantling the attachments. A starting relay, a protective thermal contact and a capacitor are usually attached to the housing. These elements contain little copper, but their removal makes further work easier. Disconnect the wires and remove the plastic or metal relay casing, which is often attached to a spring bracket.
☑️ Preparing the compressor for opening
The copper tubes coming from the body deserve special attention. They must be cut as close to the wall as possible so as not to damage the internal winding during subsequent cutting. Use a sharp tool to avoid deforming the edge of the tubes, since pure copper is valued higher than contaminated or deformed copper.
Technology for opening a sealed case
The most labor-intensive stage is breaking the integrity of the steel case. There are two main methods: mechanical (cutting) and thermal (heating). The mechanical method is safer in terms of fire hazard, but requires more time and physical effort. The thermal method is faster, but carries the risk of igniting oil vapors if they remain inside.
When using grinders it is necessary to make a circular cut along the equator of the body. Hold the tool confidently with both hands, maintaining a 90-degree angle to the metal surface. Do not press too hard and let the disc do the work, otherwise it may burst. It is important not to damage the internal winding of the stator if you plan to extract copper using the burning method.
⚠️ Attention: When cutting metal, sparks can fly several meters. Remove flammable items and ensure there is a fire extinguisher or sand bucket near the work area.
If you choose the burning method (burning a hole), remember that the varnish vapors impregnated with the winding are extremely toxic. You can only work in a respirator with good filters or in fresh air on the leeward side. Heating is carried out with a gas burner until red hot, after which the body is broken through with a crowbar.
Why can’t you just break the body with a hammer?
Simply breaking the body with a sledgehammer often leads to steel shell fragments being tightly stuck between the turns of the copper winding. It is almost impossible to remove them later without damaging the copper, which reduces the grade of scrap.
Removing the stator and winding
After removing the top cover of the housing, you will see the internal contents: a stator with winding, a rotor and a shaft. The stator is a collection of electrical steel plates pressed together. It is in the grooves of the stator that the very copper wirefor which the whole process was started is located.
To remove the winding, it is necessary to free one of the sides of the stator. Often it is enough to simply knock the core out of the body if it is not welded. In some compressor models, the winding is varnished and fits tightly to the walls, which makes dismantling difficult. Carefully pry the edges with a chisel, being careful not to cut the turns.
There is a technique in which the stator is heated to soften the varnish, after which the winding can be pulled out entirely. However, most often the copper is simply burned or cut out along with some of the steel and then cleaned. The purity of copper directly affects the final cost of scrap, so try to minimize the penetration of steel and insulation into the final product.
| Component type | Material | Approximate weight (kg) | Liquidity |
|---|---|---|---|
| Stator winding | Copper (Cu) | 1.2 – 2.5 | High |
| Case (shell) | Steel | 6.0 – 10.0 | Low |
| Tubes and wires | Copper/Aluminum | 0.3 – 0.5 | Medium |
| Rotor and shaft | Steel | 3.0 – 5.0 | Low |
Cleaning copper from insulation and varnish
The resulting copper mass is usually covered with a layer of enamel or varnish insulation. To deliver scrap to collection points for non-ferrous metals, it is required pure copper (class "Gloss" or "Mix"), so the insulation must be removed. There are several cleaning methods, each of which has its own pros and cons.
The thermal method (burning) is the most common among private owners. The winding is placed on a metal sheet and set on fire. The varnish burns off, leaving clean metal. However, in this case, up to 5-10% of the mass is lost due to surface oxidation, and acrid smoke is also released. This method is suitable for large volumes, but requires good ventilation.
The mechanical method is more labor-intensive, but saves the mass of the metal. You can use a special wire stripper or run the wire through a tool with blades. The chemical method involves the use of acids, but it is hazardous to health and requires the disposal of aggressive reagents, so it is rarely used at home.
⚠️ Attention: When insulation is burned, dioxins and other toxic substances are released. Never carry out this operation indoors or near residential buildings, so as not to harm yourself and your neighbors.
Sorting and delivery of non-ferrous scrap
After cleaning, the copper is sorted. Tinned copper (tin-coated) is separated from untinned copper, since the price for them is different. It's also important to make sure there are no pieces of steel, solder, or plastic stuck to the copper pile. Reception points use spectrometers or simple magnets to check the quality of raw materials.
The steel body, rotor and shaft also have value, but are classified as ferrous scrap (3A or 5A). They can be handed in separately, having been weighed in advance. Aluminum elements, if present (for example, in some types of windings or fans), are sold separately at the price of aluminum.
For maximum profit, it is recommended to accumulate non-ferrous metal. One compressor will not cover the cost of tools and time, but a series of 5-10 units is already a commercially interesting lot. It is better to store copper in a dry place to avoid oxidation and the appearance of patina, which reduces the grade.
Frequently asked questions (FAQ)
Exactly how much copper can be obtained from one compressor?
The amount of copper depends on the power and year of manufacture of the refrigerator. On average, about 1.2–1.5 kg of pure copper comes out of a standard household compressor weighing 10-12 kg. In powerful industrial models, the output can reach 2.5 kg.
Is it possible to hand over the entire compressor without disassembling it?
Yes, many collection points accept entire compressors, but the price per kilogram will be significantly lower, since the metal will be considered mixed scrap or “containerized”. Disassembly increases the cost of raw materials by 2-3 times.
Is it dangerous to open a compressor if it was running on freon?
Modern freons (R134a, R600a) are not toxic under normal conditions, but R600a (isobutane) is a flammable gas. Before cutting, you need to make sure that the system is completely depressurized and the gas has evaporated to avoid popping or ignition.
What to do with oil drained from the compressor?
Technical oil is classified as hazard class 3-4 waste. It should not be poured down the drain or onto the ground. The oil should be collected in a sealed container and taken to special waste oil collection points or disposed of through municipal services.