Melting metals at home temperature. How to melt copper at home

You will need

Crucible
Crucible tongs
Muffle furnace
Charcoal
Household vacuum cleaner
Steel wire hook
Form

Instructions

When the desired temperature is reached and the metal melts, open the door, grip the crucible with tongs. Pull the oxide film to the side with a wire hook. Pour the melt into a prepared mold. If the muffle furnace is of sufficient power, it can be used to melt any alloys and red copper.

If there is no muffle furnace, you can melt copper by autogenous, directing the flame from the bottom of the crucible upwards. In this case, melting will occur with good air access. To protect the metal from intense oxidation, it is recommended to sprinkle its surface with a layer of crushed charcoal.

Yellow copper (brass) and low-melting bronzes can be melted with a blowtorch. The principle of melting is the same as when using an autogen. The flame should cover the crucible as much as possible.

If there is no autogen, no blowtorch, you can use a simple horn. In this case, place the crucible on top of the charcoal layer. To increase the temperature of coal combustion, use forced air injection into the combustion zone. A household blower vacuum cleaner is suitable for this. The vacuum cleaner hose must have a metal tip. The tip opening can be narrowed for a finer airflow.

Related Videos

To melt copper, like any other metal, it is better to use special equipment and work under the guidance of a master. But if circumstances forced you to start melting metal at home, then make a special melting furnace.

Instructions

At both ends of the pipe, make two holes (locking) to attach the nichrome thread. Nichrome thread is a heating element, it must be attached together with a piece that will protect the turns of the wire when winding.

Using the formula L = RxS, calculate the length of the thread, where the resistance of the heating element is –R, S is the cross-section of the wire (nichrome); resistivity of nichrome –r and equal to 1.2; the desired length is L.

Wrap the wire together with the cord in the form of a spiral and coat liquid glass... Then remove the conductor, wrap the spiral with asbestos.

Make a temperature sensor. Take chromel and alumel wires and twist them together. Connect the wire from the transformer (latra) to one end of the twist. Set the transformer regulator to zero division.

The temperature sensor is located on the left. one). transformer (latr), 2). first contact on the terminal, 3). from latra the second contact, 4,5). chromel and alumel wire, 6). a cup made of a substance that conducts a current, 7). composition (mixture) of borax and graphite, 8). twisting of two wires (soldered).

Apply current for a few seconds. A melt ball should appear at the point of contact. Mount the working part of the thermocouple into the furnace lid and connect it to a millivolt, which is rated at 500 millivolts.

Re-calibrate the scale, the reference point can be the melting point of different metals. Perform this operation in the finished oven. The top cover of the furnace and the bottom are made of clay (chamotte). The oven can be supplemented with a special glass viewing window.

1) asbestos thermal insulation 2). clay pipe, 3). nichrome spiral, 4). cover (top), 5). output of nichrome thread (wire), 6). thermocouples, 7). millivoltmeter, 8) under. If the charge will be loaded directly into the furnace itself, and not into the crucibles, then coat the inside of the furnace with graphite paste. Stir the paste on liquid glass. When working with such a furnace, observe safety precautions.

Before the metal is embodied in a specific product, it must go a long way. And it all starts with a nondescript piece of rock discovered by geologists. Metal-bearing ores are composed of ore matter and waste rock. After the beneficiation process, the ore is sent for smelting.

Instructions

Pig iron is obtained from four types of iron ores - brown, feldspar and magnetic iron ore, which are from each other by percentage. Pig iron is smelted in huge blast furnaces with the addition of manganese.
First, load coke into it, and then in layers - agglomerate and coke. Agglomerate is a specially prepared ore sintered with a flux. Smelting cast iron by blowing heated air and oxygen into the furnace, creating the necessary temperature for this. In particular, feed into the ring tube around the bottom of the oven and from there through the tubes through special holes in the hearth - tuyeres - into the hearth.

In the hearth, coke is burned with the formation of CO2, which then rises through the layers of incandescent coke and, interacting with it, forms CO - carbon monoxide. It also recovers a significant part of the ore, turning it back into CO2. Remember that ore recovery takes place mostly at the top of the mine.

In order to get rid of unnecessary impurities, use a flux, when interacting with which they turn into slag. In the process of reducing the ore, the iron becomes solid. Descending into the steam - the hotter part of the furnace - iron is mixed with carbon, resulting in cast iron.

The molten cast iron flows into the hearth, and the slags form a film on its surface that protects the cast iron from oxidation. The molten mass, as it accumulates, is drained through special holes, which are sealed with clay during the melting process. To speed up the smelting process of iron ore, practice feeding oxygen-enriched air into the blast furnace, which eliminates the need for preheating. Blast furnaces using this technology look more compact, their productivity is one and a half times higher and they require a quarter less coke.

Copper and copper alloys can be prepared in all furnaces providing temperatures of 1000-1300 ° C. However, it is preferable to use units in which overheating to these temperatures is carried out in a shorter time. In this regard, furnaces used in modern practice for melting copper and copper alloys can be arranged in the following sequence: electric induction (high-frequency, low-frequency and industrial frequency) furnaces, electric arc with an indirect arc (DM), crucible and reflective (flame) furnaces, heated fuel oil or gas. The choice of the furnace is determined by the type of alloy, the need for metal, the requirements for castings, the territorial conditions of production, economic considerations, etc. In copper foundries, therefore, one can find both antediluvian forges heated with coke and modern electric furnaces. Best quality metal is obtained by melting in induction furnaces, but with proper melting, good results can be achieved using any of the listed furnace units.

Smelting of copper, bronze and brass in different furnaces is basically similar, but there are specific features depending on the design of the furnace, melting time, the possibility of using fluxes, variety of charge, etc. The general requirement is that the melting time of the metal is minimal, the metal is clean oxides, gases and harmful impurities, irretrievable losses of metal were small; the technology was simple and reliable, and the material and maintenance costs were minimal.

Pure copper is used in technology mainly in the form of rolled products (wire, sheets, rods, etc.). Shaped cast products from copper are difficult to obtain due to its low casting properties. Ingots for rolling are produced by casting into water-cooled molds or by a continuous method.

Melting copper, if necessary immediately a large number of metal, produced in flame reflecting furnaces with a capacity of up to 50 tons and above. For small-scale production, copper can be smelted in electric furnaces as well as in crucible furnaces. Highly pure oxygen-free copper is melted in vacuum induction furnaces or in furnaces with a controlled atmosphere, excluding contact with oxygen.

Smelting copper consists either in simple melting and overheating it to the required temperatures, followed by deoxidation, or at the same time, during the melting process, it is refined (purified) from impurities if the charge used contains a significant amount of impurities (5-10%).

Refining smelting is carried out in reverberant combustion furnaces where the atmosphere can be easily changed. The process of oxidation-refining smelting consists in sequence of oxidation of impurities, removal of formed oxides of impurities and reduction of dissolved copper oxide.

Oxidation occurs from the beginning of melting and throughout the entire period of melting of the charge; for this, a strongly oxidizing atmosphere is maintained in the furnace. Zinc, iron and other impurities are oxidized. Naturally, copper is also oxidized at the same time. For a more complete removal of harmful impurities, the molten copper bath is purged with compressed air or oxygen. Oxidation of impurities occurs in a sequence corresponding to the elasticity of dissociation of their oxides, both as a result of a direct reaction between oxygen and an impurity, and due to the interaction of copper oxide Cu 2 O with impurities that have a higher chemical affinity for oxygen than copper:

Cu 2 O + Me = MeО + 2Cu.

According to the law of effective masses, most of the impurities are oxidized through Cu 2 O, in addition, Cu 2 O dissolves well in copper and provides convenient conditions for the oxidation of impurities throughout the volume of the metal. The sequence of oxidation of impurities present in copper is as follows: zinc, iron, sulfur, tin, lead, arsenic, antimony, etc. oxygen.

The resulting oxides, which have a basic character, float up and are slagged with slag silica:

ZnO + SiO 2 → (ZnO SiO 2),

FeO + SiO 2 → (FeO SiO 2)

Together with impurities, Cu 2 O also passes into the slag in quantities determined by the chemical equilibrium between the metal and the slag:

+ (SiO 2) → (Cu 2 O SiO 2).

This reaction is undesirable: it increases the loss of copper. Therefore, the slag is selected in such a way that it contains oxides whose basicity is higher than that of copper oxide, and they would displace Cu 2 O from the slag into the metal by the reaction

(Cu 2 O SiO 2) + (Me`O) → (Me`O SiO 2) +.

Such oxides can be CaO, MnO, FeO, etc. In practice, for this purpose, the main open-hearth slag of the following composition is used: 24-40% CaO, 10-15% FeO, 10-15% Al 2 O 3, 8-12% MnO and 25-30% SiO 2. Slag is brought to the surface of copper during smelting in the amount of 1.5-2% by weight of the charge. To liquefy the slag, fluorspar CaF 2, cryolite Na 3 AlF 6, soda ash Na 2 CO 3, etc. are additionally added to it.

Slagging of impurities is accelerated by stirring the metal with slag. Stirring the metal also facilitates the removal of lead from copper, since it settles on the bottom due to its higher density. Sulfur is removed during the oxidation period in the form of a gaseous product SO 2 by the reaction:

Cu 2 S + 2Cu 2 O ↔ 6Cu + SO 2.

During the removal of sulfur, the metal is "boiled".

The completeness of the oxidation of the melt is determined by taking samples for fracture. A dense, unpatched, coarse-crystalline brown fracture indicates the end of the oxidation period of the melt. Slag is removed from the surface of the liquid metal and the recovery of copper oxide, which is contained in the solution after removal of the slag, to 10%, is started. Such copper is brittle in the solid state and without deoxidation is unsuitable for casting ingots. The atmosphere of the furnace is made reductive, i.e.

torch combustion occurs with excess fuel and lack of air (smoky flame). The recovery of copper from nitrous oxide is enhanced by an operation commonly referred to as “teasing” the metal. Teasing is performed by dipping raw aspen or birch logs into the melt. When wood burns, water vapor and wood distillation products (hydrogen and hydrocarbons) are released, as a result of which the metal boils violently, mixes well and interacts more actively with the reducing atmosphere of the furnace.

During this period, the surface of the bath is covered with charcoal to enhance the reducing atmosphere. Copper oxide dissolved in metal, in contact with such an atmosphere, is reduced: Cu 2 O + CO = 2Cu + CO 2.

Since copper at this moment contains a large amount of oxygen, immersion of raw logs is relatively harmless with regard to the possibility of saturating the metal with hydrogen, since its solubility in copper with a significant amount of oxygen is very low.

A fracture test of well deoxidized copper has a dense, fine-grained fracture of light pink color. The metal is considered ready for pouring when the copper oxide content is brought to about 0.4%, a further reduction in the Cu 2 O content is not considered desirable, since from this moment the risk of copper saturation with hydrogen increases, which, during the subsequent crystallization of the spilled copper, is able to interact with oxygen with the formation of water vapor bubbles, which reduce the density and properties of copper.

Smelting copper from pure charge consists of melting, overheating, deoxidation and casting. For this purpose, electric induction furnaces are used in the procurement shops. Smelting is usually carried out under a protective cover of calcined charcoal, which protects the metal from oxidation. After melting the charge, a deoxidizer is introduced into the bath - phosphorous copper in an amount of 0.1-0.3% of the charge weight. Then the melt is thoroughly mixed, controlled by the break, kept for 3-5 minutes, and then, upon reaching the temperature of 1150-1200 ° C, it is poured.

Lithium is also used to remove oxygen, which is a good copper deoxidizer. Sometimes a complex deoxidizer of lithium and phosphorus is used (when it is necessary to obtain a particularly pure metal), as well as magnesium.

However, almost all deoxidizers, remaining in copper, reduce its most important property - electrical conductivity, therefore, they strive for their amount in copper to be minimal, and the highest quality oxygen-free copper is melted in furnaces with a special protective atmosphere in the form of a generator gas or in a vacuum, in which deoxidation is not required.

Oxygen-free copper contains at least 99.97% Cu - it is more ductile than conventional copper, more corrosion-resistant and has high electrical conductivity.

Despite the poor casting properties of copper, in particular low fluidity, rather complex hollow castings can be obtained from it by casting in sand or metal molds. In this case, copper must be very well deoxidized and purified from hydrogen (by blowing with nitrogen). To improve its casting properties, up to 1.0% Sn + Zn + Pb is introduced. The smaller the amount of these elements is possible to obtain a shaped casting, the higher its properties (electrical conductivity and thermal conductivity). Blast furnace tuyeres, valves, rings and other parts are cast from such copper.

Copper is extremely popular and common metal used in the manufacture of electronics, power transmission, and the manufacture of a variety of alloys.

What is the melting point of copper, how is it mined and why it is interesting? Let's talk about all this.

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How copper is obtained

The reserves of this metal on Earth are relatively small (in comparison with other elements). Moreover, it is found both in the form of nuggets and in composition of complex compounds... Most often it is copper pyrite, chalcopyrite, bornite and chalcocite. They are found in sedimentary rocks, but most often in hydrothermal veins. Total amount copper deposits in the world quite large, but really large, having an important strategic importance, just a few .

On Russian territory this is Udokan, located in the Trans-Baikal Territory. If we consider Europe, the largest field is the German Mansfeld. In the near abroad, Kazakhstan can boast of such reserves - they are in the city of Zhezkazgan.

Serious melliferous belt is located in Central Africa. The USA also has large deposit- Morency. Finally, Chile can boast of two serious mining points at once - Kolyausi and Escondida.

Copper ore is mined open method. Only a relatively small part of the deposits, where the raw materials lie at great depths, use the mine method.

After mining, the ore undergoes the most complex processing, which allows to separate the pure metal from the slag. For this, different methods are used: electrolysis, hydrometallurgy, as well as pyrometallurgy.

How did our ancestors melt copper?

This is the oldest metal that people have mastered. Amazing plasticity has become its main advantage. It is thanks to him that, even with primitive tools of labor, it is possible to process metal, making household items from it and various tools of labor.

Our ancestors learned how to process the first metal in about 4th millennium BC... Finding boulders of unusual color, people tried to process them, habitually hitting them with heavy stones. However, the nuggets did not split, but only deformed. Thus, the primitive masters were able to to make the first tools of labor.

This was the reason for the transition from the Stone Age to the Copper Age. It took no more effort to make metal weapons than stone ones. But it served much longer, and if damaged copper ax or the knife could be repaired - the stone counterparts had to be made anew.

How many degrees does copper melt? Today this temperature does not seem large to specialists - only 1083 degrees Celsius.

However, for ancient metallurgists it was unattainable, so they learned to melt material for full processing much later - only in the 3rd millennium BC, when the necessary technologies appeared. However, even before that, in many settlements, craftsmen heated copper nuggets on bonfires, noting that hot metal lends itself to processing much easier.

What has changed over time

Of course, modern copper products cannot be compared with those that were made five thousand years ago. Instead of rough brass knives axes and arrowheads and spearheads today, the most complex parts for electronics are produced. But all the properties of the metal remained unchanged. At what temperature does copper melt today, at the same temperature it melted thousands of years ago. But significantly technology has improved.

For example, used to be clean (relatively clean, of course) metal from ore mined in the most primitive ways. For example, ore and coal were put into an earthen jug. The vessel was placed in the pit, the mixture was set on fire, and the pit was filled up. Carbon monoxide was released when coal was burned. When in contact with the ore, he triggered a reaction, as a result of which metal was released and a small amount of water.

Today, as mentioned above, different methods are used to remove impurities from ore. Using a dedicated copper melting graph and different processing methods, specialists can get almost absolutely pure metal. Consider, for example, hydrometallurgical as the easiest to understand.

Copper ore is poured sulfuric acid... Copper, as a relatively active metal, reacts to form copper sulfate. Iron, upon contact with it, displaces copper. The reaction produces ferrous sulfate and copper.

Physical properties

Has a rare color- golden pink, which is very unusual for metals. It reacts relatively easily, and also combines with other metals, significantly changing their properties. A demonstration of this is the combustion process - enough mix pure metal with sulfur and heat the mixture.

It is made in demand by its excellent electrical conductivity - the best indicators possesses only silver.

In addition, it boasts good thermal conductivity, which makes it an irreplaceable material in the production of thermal cooling pipes and radiators... The boiling point of copper is quite high - 2567 degrees Celsius.

Fuse metal at home or industrial goes the same way. The temperature rises gradually and constantly. However, when enough heat is received, the crystal lattice is destroyed. At this point, the temperature stops rising despite the fact that heating does not stop. Melting temperature of copper as mentioned above is 1085 degrees Celsius . Only after the metal has completely melted will the temperature rise continue. It boils at 2567 degrees Celsius.

When cooled, the crystal lattice is restored and the metal solidifies. The crystallization temperature is 1085 degrees, and with a decrease it becomes even more dense.

Alloys can have strong excellent melting point... For example, the melting point of aluminum and copper is 1040 degrees Celsius.

How to melt at home

Some people have hobbies associated with metal casting... Those who are just embarking on this fascinating path are often interested in how to melt copper at home. For this you will need:

melting mold;
forceps;
raw materials for smelting;
a high-pressure gas burner is the best solution, since not every household has a furnace;
protective equipment (goggles, thick gloves).

Once you have everything you need, you can start melting at home. Step-by-step instruction pretty simple:

Grind the metal as much as possible- can be turned into sawdust with a file. This will melt it faster.
Place in a melting dish- it must be of a material with a high melting point.
Wear protective equipment, ignite the burner and direct the flame towards the raw material.
When the copper melts grab the melting mold with tongs and pour the liquid metal into the prepared mold.

As you can see, everything is pretty simple. However, this method not suitable for all alloys. For example, the melting point of steel and steel is too high - a conventional burner will not work here. This also applies to the alloy of copper and iron.

The scope of application is very extensive... Here are just a few examples:

electricity transmission- low resistance makes this metal extremely popular;
instrumentation- resistance to water, including sea water, is very important in many areas;
when soldering- also due to good electrical conductivity;
water pipes- she perfectly conducts heat;
cooling radiators- the thermal conductivity of the metal allows not only to warm the premises, but also to cool the equipment.

Useful video

Now you know all about copper, how it was obtained, history, uses, and how to process it at home. Surely this knowledge will be useful to you.

Copper products are actively used not only in various industries, but also in everyday life. In this regard, it is quite natural that many craftsmen have a question about how to melt copper and make various products from it by casting at home. Knowledge of this technology, which has been known to mankind since ancient times, makes it possible to create various objects not only from copper, but also from its alloys -.

Copper characteristics

Copper is one of the first metals that humans learned to mine and process. Articles made of copper and its alloys were used as early as the 3rd century BC, as evidenced by historical data and the results of archaeological excavations. The widespread use of copper was largely facilitated by the fact that it is quite easy to process by various mechanical methods. Moreover, it can be easily melted.

Copper, the surface of which is distinguished by a pronounced yellowish-red color, due to its softness, can be easily processed by plastic deformation. The surface of copper, when it interacts with the surrounding air, becomes covered with an oxide film, which paints it in such a beautiful color.

Of great importance are such characteristics of copper as electrical and thermal conductivity, according to which it ranks second among all metals, second only to silver. Due to these properties, products made from it are actively used in the electrical industry, as well as in cases where it is necessary to ensure rapid heat removal from a heated object.

Another important parameter of copper, which directly affects the amount of energy and labor expended in the manufacture of products from it, is the melting point. For pure copper, the temperature at which the metal passes from a solid to a liquid state is 1083 °. If you mix copper with tin and get bronze, then the melting point of such an alloy will already be 930–1140 °, depending on the content of the main alloying additive in it. Such as brass, which is obtained by adding zinc to the base metal, has an even lower melting point, which is in the range 900-1050 °.

If you decide to implement such a technological process at home as, it is important to know one more parameter - its boiling point. At 2560 °, copper literally begins to boil, which is clearly visible in the video of this process. The appearance of bubbles on the surface of liquid metal and active gas formation in it is facilitated by carbon released from copper as a result of its oxidation, which occurs during strong heating.

If you bring the stranded to a boil, then the castings from it will be of low quality, their structure and surface will be characterized by big amount pores, which reduce not only its decorative, but also mechanical characteristics.

Step by step instructions for melting copper

Smelting copper, if you prepare everything necessary for the implementation of such technological process and to approach it correctly, it allows even at home to make copper products for both decorative and purely practical purposes.

In order to melt copper, you need the following tools, equipment, and consumables:

muffle furnace (preferably with heating temperature control);
a crucible in which you will melt copper (for melting copper, crucibles made of ceramics or refractory clay are used);
tongs with which the hot crucible will be removed from the furnace;
hook (it can be made from ordinary steel wire);
household vacuum cleaner;
charcoal;
the shape into which the casting will be performed;
gas burner and forge.

You can melt copper both in production and at home by following the algorithm below.

Step one

Copper in a crushed state is placed in a crucible. Keep in mind: the smaller the pieces of metal, the faster it will melt. After filling the crucible with copper, it is placed in an oven, which, using a temperature controller, must be warmed up to the required state. In the doors of serial muffle furnaces, a window is necessarily provided through which you can observe the melting process.

Step two

After all the copper in the crucible has melted, it must be removed from the furnace using special tongs. An oxide film is always present on the surface, which must be moved to one of the crucible walls using a steel hook. The molten metal, after freeing its surface from the oxide film, should be poured into a previously prepared mold as quickly and accurately as possible. The details and rules for performing this procedure are well demonstrated by the video, which is easy to find on the Internet.

Step three

In the event that you do not have a muffle furnace at your disposal, then you can heat the crucible with copper using a gas burner, placing it vertically under the bottom of the container. It is important to ensure that the gas burner flame is evenly distributed over the entire crucible bottom area.

Step four

If at home it is necessary to melt low-melting copper-based alloys (brass and some brands of bronze), then an ordinary blowtorch can be used as a heating device, also placing it vertically under the bottom of the crucible. When melting, performed by this and the previous methods, the surface of the molten metal will actively interact with oxygen, which will lead to intense oxidation. To reduce the intensity of oxidation, the molten copper can be sprinkled with crushed charcoal.

Step five

If your home workshop has a forge, it can also be used to melt copper, brass or bronze. In this case, a crucible with crushed metal is placed on a layer of hot charcoal. In order for the heating and melting process to proceed more intensively, air can be supplied to the coal combustion zone, for which an ordinary vacuum cleaner is suitable, which does not work for drawing in, but for blowing. In the event that you will use a vacuum cleaner, a metal tip with a small diameter blowing hole must be made on its hose.

When choosing a muffle furnace for performing casting operations with copper and its alloys, one should pay attention to the temperature regime that such a device can provide. Depending on the type of metal being melted, such a furnace must provide the following heating temperatures:

copper - 1083 °;
various grades of bronze - 930–1140 °;
brass - 880-950 °.

You may decide to make a smelting furnace yourself by watching the video.

Copper products can be very beautiful, and it is tempting to make something copper with your own hands. For this, the metal must be melted. In foundry, three main varieties of this metal are used for the most part: pure red copper and its alloys: bronze and brass.

You will need

Crucible
Crucible tongs
Muffle furnace
Charcoal
Household vacuum cleaner
Iron wire hook
Form

Instructions

1. Place pieces of metal in the crucible. Place the crucible in the muffle furnace. Set the heating knob to the required position. It is allowed to monitor the melting of the metal in the furnace window, which is on the door. During melting, an oxide film forms on the metal surface.

2. When the required temperature is reached and the metal melts, open the door, grip the crucible with tongs. Slide the oxide film to the side with the help of an iron wire hook. Pour the melt into a prepared mold. If the muffle furnace is of sufficient power, with its support it is allowed to melt all kinds of copper alloys and red copper proper.

3. If there is no muffle furnace, it is allowed to melt copper by autogenous, directing the flame from the bottom of the crucible upwards. In this case, melting will proceed with excellent air access. To protect the metal from saturated oxidation, it is recommended to sprinkle its surface with a layer of crushed charcoal.

4. Yellow copper (brass) and low-melting varieties of bronze can be melted with a blowtorch. The thesis of melting is the same as when using an autogen. The flame should cover the crucible as much as possible.

5. If there is no autogen, no blowtorch, it is allowed to use a simple horn. In this case, place the crucible on top of the charcoal layer. To increase the temperature of coal combustion, use forced air injection into the combustion zone. A household blower vacuum cleaner is suitable for this. The vacuum cleaner hose must always have a metal tip. The tip opening is allowed to be narrowed to obtain a more fine jet of air.

If you need to melt the metal for any purpose, you will be faced with a number of tasks that you can solve and still perform this procedure with your own hands. Let's say melt copper not as difficult as many other materials. And if you wish, it is absolutely possible to do it yourself.

Instructions

1. Find a method to get temperatures as high as 1083 degrees Celsius. This temperature is needed in order to copper began to melt. Don't believe the stories of how people managed to melt copper over a fire in a tin can or a piece of copper wire on a spoon, using only a lighter. Even if their stories are real, there is only one result - it was not copper .

2. It is permissible to use a blast furnace if there is one where you live or if you have a chance to use it. Before renting a stove, make sure that it can heat up to the temperature you need and that there is a possibility of heat regulation in it, because it is impossible to copper began to boil. One must be able to balance between temperature extremes.

3. Try building a smelting furnace yourself at home. It is allowed to make a melting furnace at home from scrap materials. The schemes by which such furnaces are made can be found on the entire specialized forum. The most common design is created from a used fire extinguisher. If you prefer this option, then saw off the head of the fire extinguisher and attach a lockable cover. Treat the inside with clay and install the melting element, buy one that is allowed in specialized stores.

4. Remember that the mold into which the molten copper will be poured must have a coarser melting point than itself. copper .

5. Do not forget about the nitrogen environment, which must be made for successful melting, otherwise you can just waste the material.

Related Videos

To melt copper however, any other metal is better to use special equipment and work under the guidance of a master. But if circumstances forced you to start melting metal at home, then make a special melting furnace.

Instructions

1. A furnace for melting metal at home was developed by the scientist metallurgist E.Ya. Khomutov. Take an ordinary refractory pipe 300 mm long as the basis of the furnace.

2. At both ends of the pipe, make two holes (locking) in order to attach the nichrome thread. Nichrome thread is a heating element, it must be attached together with a piece of cord, one that will protect the turns of the wire when winding.

3. Using the formula L = RxS, calculate the length of the thread, where the resistance of the heating element is –R, S is the cross-section of the wire (nichrome); resistivity of nichrome –r and equal to 1.2; the desired length is L.

4. Wrap the wire together with the cord in the form of a spiral and coat with liquid glass. After that, remove the conductor, wrap the spiral with asbestos.

5. Make a temperature sensor. Take chromel and alumel wires and twist them together. Connect the wire from the transformer (latra) to one end of the twist. Set the transformer regulator to zero division.

6. Take a dielectric surface and pour in graphite powder and borax (proportion 5/1). Connect the other wire from the transformer to the place of soldering. It is indicated in the figure.

7. The temperature sensor is located on the left. one). transformer (latr), 2). on the terminal 1st contact, 3). from latra 2nd contact, 4.5). chromel and alumel wire, 6). a cup of substance, the one that does not conduct the current well, 7). composition (mixture) of borax and graphite, 8). twisting of 2 wires (soldered).

8. Apply current for a few seconds. A ball of melt should appear at the point of contact. Mount the working part of the thermocouple into the furnace lid and connect to a millivolt, the one that is rated at 500 millivolts.

9. Calibrate the scale again, the reference point can be the melting point of various metals. Carry out this operation more closely in the finished oven. The top cover of the furnace and the bottom are made of clay (chamotte). The stove can be supplemented with a special glass viewing window.

10. 1) asbestos thermal insulation 2). clay pipe, 3). nichrome spiral, 4). cover (top), 5). output of nichrome thread (wire), 6). thermocouples, 7). millivoltmeter, under. If the charge will be loaded naturally into the furnace itself, and not into the crucibles, then coat the inside of the furnace with graphite paste. Stir the paste on liquid glass. When working with such a furnace, observe safety precautions.

Brass is a multicomponent alloy of copper with several other alloying elements. Brass products have many useful qualities and are often used in the manufacture of a wide variety of designs in the practice of a home craftsman. One of the methods of primary processing of brass is melting.

You will need

- muffle furnace;
- blowtorch;
- gas-burner;
- crucible;
- charcoal;
- iron wire;
- a mold for smelting metal.

Instructions

1. Prepare a muffle furnace in which the brass will be melted and a special vessel made of refractory material (crucible), where the starting material will be easily placed. For comfortable handling of the crucible, special metal tongs and a fireproof support are required. Provide excellent ventilation in the room where the work will be carried out.

2. Place the crushed brass mass in a heat-resistant crucible. Desirable, so that the pieces of metal are not unnecessarily huge; this will shorten the melting time. Place the crucible in the muffle furnace. Using the temperature regulator, set the required value (the melting temperature of brass reaches 880-950 degrees). Turn on the oven. If necessary, control the melting process through a window located in the door of the muffle furnace.

3. After the brass has completely melted, carefully open the door, observing safety measures, and remove the crucible, gripping it with tongs. A film of oxides forms on the surface of the molten metal, remove it with a piece of iron wire. Pour the molten metal into the previously prepared casting mold.

4. In the absence of stationary equipment for melting metals, use heating with a gas torch or traditional blowtorch. Place the burner in a stable position so that the flame is directed upwards and then secure. Place the heat-resistant crucible with brass on the iron wire support.

5. Turn on the torch or blowtorch. Set the flame to such a power that it covers the entire lower surface of the refractory vessel. Due to the fact that the melting will proceed with an energetic flow of air, the process will be accompanied by powerful oxidation of the metal. To reduce oxidation, sprinkle a contented layer of crushed charcoal over the brass.

The reforming of wood into coal is carried out with the help of the pyrolysis process, which means the decomposition of organic compounds as a result of their destruction under the action of high temperature... The decomposition of wood is carried out in an oxygen-free gas environment, in a retort. In the process of pyrolysis, steam gases are released, which are discharged through the branch pipe. Later, the gas is separated from the liquid in the device. Today there are a huge number of units prepared for the thermal decomposition of wood. If you have the right materials, you can make a charcoal oven with your own hands.

You will need

- ceramic bricks;
- fireclay brick;
- clay and sand;
- iron sheet;
- blower fan;
- cast iron grates;
- lever thermostat;
- doors.

Instructions

1. Before proceeding with the assembly of such equipment, the entire master draws up a detailed diagram of the upcoming furnace. With an independent manufacture of the apparatus, it is more excellent than each to take a more closely ready-made scheme.

2. The perimeter of the pyrolysis oven is laid out of ceramic bricks, on which there should be no cracks or chips. Internal partitions are laid using fireclay bricks. Clay and clean sand are used to prepare the binder solution.

3. The firebox can be made of ceramic and fireclay bricks. It is preferable to use fireclay brick, because it is better able to withstand high temperatures, which cannot be avoided when burning fuel.

4. The firebox is divided into two segments: a loading and a section for combustion of gases released during the pyrolysis process. For best combustion volatile matter secondary air is supplied to this section, while the passage of the primary one occurs from top to bottom.

5. Cast iron grates are installed in the firebox. In this case, it is necessary to make small gaps, because when heated, the gratings expand. The fire doors are fixed by means of special "ears". For their manufacture, it is allowed to use wire or sheet metal.

6. Later, you need to install the doors, prepared for adjusting the air supply and cleaning the furnace from ash. At the same stage, the stove valves are mounted, with the help of which the draft is regulated in the stove. Due to the fact that the design of the furnace has a large aerodynamic resistance, it is required to install a fan used to supply forced draft.

7. The charcoal stove has such advantages as the likelihood of utilizing waste from the wood industry, the lack of emissions of harmful substances in environment, easy maintenance and operation, safety and durability. With so many pluses, there is one drawback, one that is impossible not to notice. It consists in the need for careful thermal insulation of the pipe, because at low temperatures the condensate in the pipe can freeze, and this will lead to a decrease in its cross section.

Useful advice
The production of a charcoal stove should be carried out using only solid materials. It is desirable to have a skill in carrying out welding work.

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Note!
The muffle furnace should allow obtaining the following temperatures: for melting copper - 1083 ° C, for melting bronze - 930-1140 ° C, for melting brass - 880-950 ° C. Red copper is tough. It is of little use for thin casting. For these purposes, brass is more suitable. The lighter the brass, the more fusible it is. It is not recommended to remelt old bronze of unknown origin, because it may contain a huge amount of arsenic in its composition. The forge is an open fired oven that burns charcoal. To increase the temperature, additional air is blown into the furnace with the support of bellows or a compressor.

Useful advice
For melting copper, clay and ceramic crucibles are used. Instead of a furnace, it is allowed to use an autogen or a blowtorch.

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