At what temperature does lead melt?

At what temperature does lead melt: properties and melting point, melting procedure and safety precautions - Machine

Fusibility is the ability of metals to change from a solid to a liquid state at a certain temperature. This temperature is called the melting point. Different metals have different, but specific (for a given metal) melting point.

Alloys do not have a constant and definite melting point; it depends on the quantity and properties of the elements included in the alloy.

So, for example, if the melting point of lead is 327 C, and tin is 232 C, then an alloy of tin (62%) with lead (38%), called solder, has a melting point of 183 C. [46]

Fusibility is the ability of metals to change from a solid to a liquid state at a certain temperature. This temperature is called the melting point. Different metals have different, but specific (for a given metal) melting point.

Alloys do not have a constant and definite melting point; it depends on the quantity and properties of the elements included in the alloy.

So, for example, if the melting point of lead is 327 C, and tin is 232 C, then an alloy of tin in the amount of 62% with lead in the amount of 38% (the so-called solder) has a melting point of 183 C. [47]

Fusibility is the ability of metals to change from a solid to a liquid state at a certain temperature. This temperature is called the melting point. Different metals have different, but specific (for a given metal) melting point.

Alloys do not have a constant and definite melting point; it depends on the quantity and properties of the elements included in the alloy.

So, for example, if the melting point of lead is 327 C, and tin is 232 C, then an alloy of tin (62%) with lead (38%), called solder, has a melting point of 183 C. [48]

Crucible furnaces usually do not have a thermocouple or thermometer to measure temperature. The approximate temperature in the furnace is judged by the color of the heated ceramic muffle: dark red heat - 700 C, bright red - 950 C, yellow - 1100 C. After 10 - 12 minutes, the crucible is carefully removed, grasping it with crucible tongs.

It must be emphasized that it is advisable to perform this operation without delay, without allowing the crucible to cool. When cooled, the metal can sometimes fuse to the crucible and is then difficult to remove without breaking the crucible.

For reduction, oxides of low-melting metals are chosen (melting point of lead 327 C, tin 232 C) in order to obtain molten metal in laboratory conditions. [49]

Lead is plastic and tough, easy to process. A fresh cut of lead in air quickly becomes dull, as the lead is oxidized by oxygen in the air. Due to its high viscosity, lead is difficult to break. The mechanical strength of lead is very low. It is so soft that it can be drawn with a fingernail, easily cut with a knife, easily bent and torn even with relatively little effort.

The thermal conductivity of lead between 0 and 50 is equal to 30 kcal/hour C, the heat capacity between O and 100 is equal to 0 031 kcal. C, linear expansion coefficient is 0 0000276 - 0 0000293, sp. The melting point of lead is 327 5, so it can very easily be melted in a ladle on a simple hearth and cast into any shape.

Ease of processing is the most valuable property of lead compared to other materials. [50]

This metal melts at a low temperature, which can be achieved using an ordinary gas burner or electric stove.

Read also: DIY pipe clamps

Lead Characteristics

The predominant source of raw materials is sulfide polymetallic ores . Metal has the following qualities:

• softness;
• low melting point;
• You can process this metal yourself.

This material is characterized by a dirty grayish tint . In the cut area, the metal has a bluish tint, which gradually becomes dull. This is due to the oxidation process, which occurs due to the influence of oxygen. An oxide layer is formed on the cut.

It is a heavy metal, its density is 11.34 g/cm³ . This figure is approximately one and a half times higher than that of ordinary iron. Among other things, lead is also one of the softest metals.

Its surface can be easily scratched even with an ordinary knife or fingernail. Lead is extremely flexible; this metal can be flattened with an ordinary mallet or hammer. It is also often used for casting or melting with your own hands.

Melting temperature

This metal begins to melt at a temperature of 327.46 degrees Celsius . Its casting qualities are fully preserved within the range from four hundred to four hundred and fifty degrees.

And the oxide film, which protects the material from corrosion, begins to melt only at a temperature of 850 degrees Celsius, which makes it difficult to weld this type of metal with others. In addition, the volatility level of lead increases significantly at a temperature of 700 degrees.

The material is perfectly processed even when chilled. You can make a thin layer of foil from it. If this metal is subjected to a pressure of 2 tons per square centimeter, then it takes on the appearance of a monolith.

Wire is made from it by pressing in a die. The low degree of tensile strength does not allow the use of ordinary drawing for this purpose.

Preparing to smelt lead

The material can also be melted in an outdated container made of cast iron, using a deep and long spoon for pouring .

If there is no suitable container nearby, then you can use an ordinary tin can. However, here you should use pliers , which will be used to remove the hot pan from the flame and pour the material into the mold.

Do not forget that you need to be extremely careful while working. To simplify the procedure, you can make a small groove . In this case, the red-hot metal will pour out in a thin stream clearly into the required place.

The material, cleared of impurities, can be crushed so that it melts as quickly as possible. The container must be securely placed over the burner and heated properly . This must be done in order to rid the surface of excess impurities and moisture.

Melting procedure

First melt two or three pieces to form a puddle, then gradually add new material . This will give you the opportunity to make your work area more voluminous.

After melting, a layer of debris, impurities and slag must be removed . Pouring must be done into a heated mold. Lead is also characterized by rapid solidification. The material quickly loses its fluidity, becomes thicker, and therefore cannot completely fill the mold.

Source: https://regionvtormet.ru/prochee/pri-kakoj-temperature-plavitsya-svinets-svojstva-i-temperatura-plavleniya-protsedura-plavki-i-mery-bezopasnosti.html

Melting point of lead at home

Melting lead is not difficult. This can be done even at home using a suitable thin-walled steel or even aluminum container. The melting point of lead is low. To achieve it, a flame from a burner on a household gas or electric stove is sufficient.

Lead: characteristics

Distribution in the total mass of the earth's crust is 0.0016%. This seems to be small, but if we compare this indicator with its closest neighbors on the table of chemical elements - mercury, gold, bismuth, then lead occupies a much higher place. The main source of raw materials for its production is polymetallic sulfide ores.

The material has a characteristic dirty gray color. When cut, lead shines with a bluish tint, but soon fades. This oxidation occurs when exposed to air. A thin layer of oxide forms on the cut surface. The metal is heavy, its density is 11.34 g/cm³. This is one and a half times more than iron, and four times more than aluminum.

In addition to the fact that the melting point of lead is low, it is also one of the softest metals. It can be scratched with a fingernail or cut with a knife. It is flexible enough to be flattened with a hammer. The material is well suited for melting and casting even at home.

Technological properties: what is the melting point of lead?

It melts at 327.46 °C (600.61 K). Maintains high technological casting properties in the range from 400 to 450 °C. The boiling point of lead is 1751 °C (2022 K).

The oxide film required for corrosion protection melts only at 850 °C. Such a high temperature, significantly exceeding the melting regime, complicates the process of welding lead in alloys with other metals.

In addition, at 700 °C the volatility of lead increases noticeably.

When cold, the material lends itself well to processing. It can be rolled into thin foil. At a pressure of 2 t/cm², crushed lead is compressed to form a monolithic mass. Wire is produced from it not by casting, but by pressing solid material through a die. Low tensile strength does not make it possible to use conventional drawing for these purposes.

At what temperature does lead melt when combined with other metals? This will depend on the composition of the alloy and the ratio of metals in it. With one material the temperature may increase, while with others it can be significantly lower. For example, solder, which is based on tin (64%) and lead (36%), melts at 180-200 °C.

Melting at home: preparation

It is necessary to select a suitable container; it is desirable that its handle is made of heat-resistant material. An old teapot, coffee pot or other disused kitchen utensil with a comfortable handle is good for these purposes. You can also melt the material in an old cast iron pan, and use a deep spoon with a long handle to pour it.

In a pinch, a tin can will do. But here you can’t do without pliers. They can be used to remove heated dishes from the heat and pour molten lead into the prepared mold. But this should be done very carefully.

For convenience, it is better to make a groove on the rim of the tin. Then the molten metal will flow out in a thin stream without smudges and exactly in the right place.

The place for gripping with pliers should also be equipped in advance so as not to perform unnecessary manipulations with dishes and heated metal.

The lead, prepared and purified as much as possible from foreign impurities, is crushed into small pieces if possible. This way it will melt faster. The container is securely installed above the burner and warmed up. This is done to burn out moisture and unwanted impurities from its surface.

Melting and pouring process

You should not load the entire volume of prepared material into the dish at once. Only the bottom layer of lead scrap will be in contact with the heated surface, and everything on top will only absorb heat and thereby slow down the heating. It is better to first melt a few pieces to form a puddle, and then gradually add new portions of metal to it. In this case, the heating surface area increases.

After melting the entire volume of material, using a metal spatula or a spoon with a long handle, it is necessary to remove a layer of slag, impurities and debris from the surface of the melt. Pouring should be done into a heated mold.

The relatively low melting point of lead suggests its rapid solidification. This is especially noticeable in cold form.

The material loses its fluidity, noticeably thickens, the melt does not fill the mold, and the quality of the casting deteriorates.

Safety precautions

The boiling point of lead is very high (1751 °C), and it is impossible to achieve it at home. Nevertheless, its volatility becomes quite high already at 700 °C.

If the melting point is significantly exceeded, nearby people may be adversely affected by its fumes. If there is no significant technological need to overheat the melt, it should not be brought to a reddish tint.

This is precisely what indicates that the melting point of lead was exceeded.

Molten lead can cause serious burns if it comes into contact with the skin. Its drops burn through clothing and, if they come into contact with flammable materials, can cause a fire and, as a consequence, a fire, so you should work carefully. Water should not get into molten lead. This causes a fountain of silvery spray, which, if it gets into the eyes, can cause extremely undesirable consequences.

  Steel hardening temperature 40x

Work should be done in a well-ventilated area or outdoors. Do not neglect personal protective equipment. A respirator or even a cotton-gauze bandage will protect your respiratory tract from lead dust. Small doses of lead in the body may not immediately cause consequences. However, this material tends to accumulate over a lifetime and cause poisoning if permissible doses are exceeded.

Source: https://steelfactoryrus.com/temperatura-plavleniya-svintsa-v-domashnih-usloviyah/

Melting point of lead at home - Metals, equipment, instructions

Lead is a low-melting metal, so melting it is quite easy, even without special equipment. The main thing you need to know is what is the melting point of lead.

The choice of container in which the melting will take place depends on this.

For lead, an ordinary tin can is suitable, since the tin for it is made of steel, which melts at a temperature several times higher than that of the metal being smelted.

Lead and its properties

The dirty gray color of this metal is the result of the fact that an oxide film forms on its surface in a short time in the atmosphere. It is this that gives such a nondescript appearance to lead.

However, if you run a file over the surface of the metal several times, a shiny surface with a bluish tint will become visible under a thin layer of oxide film. This is a very soft and heavy material, it is almost one and a half times heavier than steel.

The density of lead is 11.34 g/cc, and the density of iron is 7.80 g/cc.

Lead was discovered in ancient times around 4000 - 4500 BC. In modern industry, it is obtained mainly by metallurgical methods from lead ores and concentrates.

Lead has a low melting point - only 327 °C, and a boiling point - 1749 °C. It is necessary to take into account the toxicity of lead vapor and the fact that this chemical element is poorly excreted from the body. The more molten lead is heated, the more it evaporates. Therefore, the room in which the melting takes place must be well ventilated.

It is due to its low melting point that lead is used in the manufacture of soft solders together with tin.

Tin Characteristics

Melts at 232 °C, boils at 2600 °C, perfectly alloys with various metals, and, due to its high ductility, can be forged well. Soldering tin is used as solder because it wets metals well. Industrial production of tin is much more difficult than lead, so it is much more expensive.

Unlike lead, tin looks much more attractive. This silvery-white metal is safe for human health. Tin is often used to cover the surfaces of metal products in places where they come into contact with food: dishes, tin plates, food foil and others.

However, tin dust and fumes can cause hazardous effects on the human body if inhaled. In addition to the production of food containers, tin is widely used in various solders and other alloys, for example, in antifriction and bearing alloys.

This material is much lighter than lead, its density is 7.3 g/cc.

Tin is polymorphic, meaning it can exist in various modifications depending on temperature. At temperatures below 13 °C, white tin (β-modification) turns into gray tin (α-modification).

As a result of this phase transition, the shiny pewter pieces crumble into a gray powder. Moreover, upon contact with the powder, white tin becomes infected with it and turns into gray.

This phenomenon was called the " tin plague ".

According to some reports, it was the main reason for the death of Robert Scott's expedition to the South Pole. Kerosene, stored in intermediate warehouses, leaked from canisters sealed at the seams with tin, which crumbled into powder in the frosts of the Antarctic. Thus, the expedition members were left almost without fuel.

Soldering alloys

Solders are classified according to various characteristics: degree of melting during soldering, manufacturing method, base metal, ability to flux, etc. Based on melting temperature, solders are:

1. Light alloy, melts at less than 145 °C.
2. Soft, melts at temperatures from 145 °C to 400 °C.
3. Solid, melting point above 400 °C.

Light alloys are used for soldering materials critical to overheating, such brands as Newton's alloy, Guthrie's alloy, Wood's alloy, POSV 32−15−53 can be mentioned.

Soft ones are used for tinning and soldering seams of dishes, electrical equipment, printed circuit boards, and heat exchanger tubes. The most common of them are tin-lead (see Table 1).

Hard solders provide high joint strength and are used for soldering load-bearing structures. These solders include copper-zinc (PMC-36, PMC-48, PMC-54), silver (PSr72, PSr70, PSr50, PSr50Kd, PSr12M) and others.

Tin-lead solders

An alloy of tin and lead with a tin content of 10 to 90% is called POS solder . The following designations of brands of such solders can be given:

• POS40 - contains 40% tin, the rest is lead, melts at 235 degrees, used in industry for tinning and soldering electrical equipment, galvanized steel products;
• POS90 - 90% tin, 10% lead, melts at 222 degrees, has found its application in the manufacture of tableware and medical equipment;
• POSSU 30−0.5 - 30% tin, 0.5% - antimony, the rest is lead, becomes liquid at 255 degrees, is used for tinning and soldering zinc sheets, ordinary and stainless steel, wires, radiators.

Depending on the percentage of tin and lead, the melting temperature of different brands of solder changes.

Melting metals

Melting is the process of a substance changing from a solid to a liquid state. Unlike alloys, in pure metals melting and solidification (crystallization) occurs at a constant, strictly defined temperature. It distinguishes between metals:

• low-melting , melts at temperatures up to 600 °C;
• medium-melting - from 600 °C to 1600 °C;
• refractory - over 1600 °C.

Table 2 indicates at what temperature lead melts, at what temperature tin and other metals melt.

Melting temperatures of metals (in °C). table 2

Source: https://spb-metalloobrabotka.com/temperatura-plavleniya-svintsa-v-domashnih-usloviyah/

Features of lead, its main characteristics and application

Lead is a soft, heavy metal of a silver-gray color, shiny, but quickly losing its shine. Along with tin and copper, it is one of the elements known to mankind since ancient times. Lead was used very widely, and even now its use is extremely diverse. So, today we will find out whether lead is a metal or a non-metal, as well as a non-ferrous or ferrous metal, we will learn about its types, properties, application and extraction.

Lead is an element of group 14 of D.I. Mendeleev’s table, located in the same group with carbon, silicon and tin. Lead is a typical metal, but it is inert: it reacts extremely reluctantly even with strong acids.

Molecular weight is 82. This not only indicates the so-called magic number of protons in the nucleus, but also the large weight of the substance. The most interesting qualities of the metal are associated precisely with its great weight.

The concept and features of lead metal are discussed in this video:

Lead is a metal that is quite soft at normal temperatures and is easy to scratch or flatten. This plasticity makes it possible to obtain metal sheets and rods of very small thickness and any shape. Malleability was one of the reasons why lead began to be used since ancient times.

The lead water pipes of Ancient Rome are well known. Since then, this type of water supply system has been installed more than once and in more than one place, but it did not operate for so long. Which, without a doubt, saved a considerable number of human lives, since lead, alas, with prolonged contact with water, eventually forms soluble compounds that are toxic.

Toxicity is the very property of a metal due to which they try to limit its use. Metal vapors and many of its organic and inorganic salts are very dangerous for both the environment and people. Basically, of course, the workers of such enterprises and residents of the area around the industrial facility are in danger. 57% is emitted with large volumes of dusty gas, and 37% with converter gases. There is only one problem with this - the imperfection of purification plants.

However, in other cases people become victims of lead contamination. Until recently, the most effective and popular gasoline stabilizer was tetraethyl lead. When fuel burned, it was released into the atmosphere and polluted it.

But lead has another, extremely useful and necessary quality - the ability to absorb radioactive radiation. Moreover, the metal absorbs the hard component even better than the soft one. A 20 cm thick lead layer can protect against all types of radiation known on Earth and in nearby space.

Advantages and disadvantages

Lead combines extremely useful properties, turning it into an irreplaceable element, and downright dangerous ones, which make its use a very difficult task.

The advantages from the point of view of the national economy include:

• fusibility and malleability - this allows you to form metal products of any degree of complexity and any subtlety. Thus, for the production of sound-absorbing membranes, lead plates with a thickness of 0.3–0.4 mm are used;
• lead is able to form an alloy with other metals (including tin, copper, zinc, etc.) that under normal conditions do not alloy with each other; its use as solder is based on this quality;
• metal absorbs radiation. Today, all elements of radiation protection - from clothing to the decoration of X-ray rooms and rooms at testing sites - are made from lead;
• The metal is resistant to acids, second only to noble gold and silver. So it is actively used for lining acid-resistant equipment. For the same reasons, it is used to produce pipes for the transfer of acid and for wastewater in hazardous chemical plants;
• The lead-acid battery has not yet lost its importance in electrical engineering, as it allows one to obtain a high voltage current;
• low cost - lead is 1.5 times cheaper than zinc, 3 times cheaper than copper, and almost 10 times cheaper than tin. This explains the very great benefit of using lead rather than other metals.

The disadvantages are:

• toxicity - the use of metal in any type of production poses a danger to personnel, and in case of accidents - an extreme danger to the environment and the population. Lead belongs to substances of hazard class 1;
• Lead products should not be disposed of as regular waste. They require disposal and sometimes it is very expensive. Therefore, the issue of metal recycling is always relevant;
• Lead is a soft metal, so it cannot be used as a structural material. Considering all his other qualities, this should rather be considered a plus.

Next, the melting point and density of lead, specific heat capacity and mass, as well as other properties and characteristics of such a metal will be considered.

Properties and characteristics

Lead is a soft, malleable, but also heavy and dense metal. The molecular lattice is cubic, face-centered. Its strength is low, but its ductility is excellent. The physical characteristics of the metal are as follows:

• density at normal temperature 11.34 g/cm3;
• melting point – 327.46 C;
• boiling point – 1749 C;
• resistance to tensile load – 12–3 MPa;
• resistance to compressive load – 50 MPa;
• Brinell hardness – 3.2–3.8 HB;
• thermal conductivity – 33.5 W/(m K);
• The resistivity is 0.22 ohm-sq. Mmm.

Like any metal, it conducts electric current, although, it should be noted, it is much worse than copper - almost 11 times. However, the metal has other interesting properties: at a temperature of 7.26 K it becomes a superconductor and conducts electricity without any resistance. Lead was the first element to exhibit this property.

In air, a piece of metal or a product made from it is quickly passivated by an oxide film, which successfully protects the metal from external influences. And the substance itself is not prone to chemical activity, which is why it is used in the manufacture of acid-resistant equipment.

Paints containing lead compounds are almost as resistant to corrosion. Due to toxicity, they are not used indoors, but are successfully used when painting bridges, for example, frame structures and so on.

The video below will show you how to make pure lead:

Over the entire temperature range, only one modification of lead is isolated, so both under the influence of temperature and over time, the properties of the metal change completely naturally. No sharp transitions were noted, when qualities change radically.

Metal production

Lead is quite common, forms several industrially important minerals - galena, cerussite, anglesite, so its production is relatively cheap. The metal is obtained by pyrometallurgical and hydrometallurgical methods. The second method is safer, but is used much less frequently, since it is more expensive, and the resulting metal still needs final processing at high temperatures.

Production using the pyrometallurgical method includes the following stages:

• ore mining;
• crushing and enrichment mainly by flotation method;
• smelting for the purpose of obtaining crude lead - reduction, furnace, alkaline, and so on;
• refining, that is, purifying black lead from impurities and obtaining pure metal.

Despite the same production technology, the equipment can be used in very different ways. This depends on the metal content in the ore, production volumes, product quality requirements, and so on.

Read below about the use and price per 1 kg of lead.

The first use of lead - in the manufacture of water pipes and household items, fortunately, dates back to quite a long time ago. Today, metal enters a home only with a protective layer and in the absence of contact with food, water and humans.

• But the use of lead for alloys and as solder began at the dawn of civilization and continues to this day.
• Lead is a metal of strategic importance, especially since bullets began to be cast from it. Ammunition for small arms and sporting weapons is still made only from lead. And its compounds are used as explosives.
• 75% of the world's metal production is used to produce lead-acid batteries. The substance continues to be one of the main elements of chemical current sources.
• The corrosion resistance of the metal is exploited in the manufacture of acid-resistant equipment, pipelines, and protective sheaths for power cables.
• And, of course, lead is used in the equipment of X-ray rooms: cladding of walls, ceilings, floors, protective partitions, protective suits - everything is made with the participation of lead. At testing sites, including nuclear ones, metal is indispensable.

The cost of metals is determined on several world-wide exchanges. The most famous is the London Metal Exchange. The cost of lead in October 2016 is $2087.25 per ton.

Lead is a metal that is in great demand in modern industry. Some of its qualities—corrosion resistance, the ability to absorb hard radiation—are completely unique and make the metal irreplaceable despite its high toxicity.

This video will tell you what happens if you pour lead into water:

Source: http://stroyres.net/metallicheskie/vidyi/tsvetnyie/svinets/osobennosti-osnovnyie-harakteristiki.html

At what temperature does lead melt: properties and melting point, melting procedure and safety precautions

Melting lead is not very difficult. You can do this yourself, using a container made of aluminum or thin-walled steel.

This metal melts at a low temperature, which can be achieved using an ordinary gas burner or electric stove.

Our planet contains 0.0016% of this metal from the total mass of the earth's crust. Although this figure is small, however, when compared with other chemical elements - bismuth, gold, mercury, lead is in a much higher position.

The predominant source of raw materials is sulfide polymetallic ores . Metal has the following qualities:

• softness;
• low melting point;
• You can process this metal yourself.

This material is characterized by a dirty grayish tint . In the cut area, the metal has a bluish tint, which gradually becomes dull. This is due to the oxidation process, which occurs due to the influence of oxygen. An oxide layer is formed on the cut.

It is a heavy metal, its density is 11.34 g/cm³ . This figure is approximately one and a half times higher than that of ordinary iron. Among other things, lead is also one of the softest metals.

Its surface can be easily scratched even with an ordinary knife or fingernail. Lead is extremely flexible; this metal can be flattened with an ordinary mallet or hammer. It is also often used for casting or melting with your own hands.

What determines the melting point of lead?

Lead occupies number 82 in D.I. Mendeleev’s periodic table. It is a silvery, malleable metal that has a silvery tint. Many people who held this material in their hands noted its high specific gravity. Lead has a low melting point and is therefore easy to process.

Melting lead in production

Application areas of lead alloys

Lead has been known to mankind for thousands of years. In ancient Rome it was used to create water pipes. It is used in various industries. Lead is made from:

1. Protective sheath for power cables.
2. Bearing connections.
3. Dyes.
4. Weights for fishing.
5. Fonts for typography.
6. Shot used for shooting from hunting rifles.
7. Protective elements for objects contaminated by radiation.
8. Alloys for soldering.
9. Plates that are installed in batteries.

In the roofing industry, this material is often used to make soundproofing coatings.

Technological properties and characteristics of the metal

To understand what products lead is suitable for, you need to understand its technical characteristics:

1. Cubic crystal lattice.
2. The heat of fusion is 327 degrees Celsius.
3. Hardness - from 3.2 to 8 HB according to Brinell.
4. Elongation - up to 70%.
5. Compression limit - up to 50 MPa.
6. Tensile strength - up to 13 MPa.
7. Voltage resistance - 0.22 Ohm.
8. Density - 11.34 g/cm³.

It lends itself well to various types of processing even without heating.

If we talk about the inert properties of the metal, then we can highlight its high resistance to corrosion. This is due to the presence of an oxide film. Withstands prolonged exposure to sulfuric, phosphoric, and acetic acid.

Lead smelting temperature

In order to cast various products from this material, it is necessary to know the melting and boiling temperatures of lead. There are several important parameters:

1. The initial melting point is 327 degrees Celsius.
2. Boiling point - 1751 degrees.

The metal achieves optimal casting properties at a temperature range of 400–450 degrees. If we talk about the melting point of lead in alloys, it is necessary to take into account the content of different components of the compound.

Melting lead - features of the metal smelting process and safety rules

Lead is one of the most accessible and in demand metals in industry. Despite its toxicity, it is actively used in many industries and in households, because lead melts at a relatively low temperature. One of the uses of lead in everyday life is the production of consumables for fishing and hunting - lead sinkers and hunting shot are often made in workshops using a handicraft method.

General characteristics of lead

Lead is one of the most common metals on earth. It is widespread on the planet, in general, this explains its widespread use by humanity since ancient times. The metal has a high specific gravity, but at the same time it is quite soft and easy to process. The density of a metal depends on temperature; the higher the temperature, the lower the density. With a high specific density, it still remains soft, and it is easy to leave an impression on its surface even with a fingernail.

The metal does not have a very expressive appearance; when forged or milled, it quickly loses its shine due to the actively recovering oxide film on the surface. It belongs to the category of heavy metals. The specific density at room temperature of 20 degrees is 11.34 g/cm3.

A distinctive property of the metal is its low melting point. The fact is that, despite such a solid specific density and belonging to heavy metals, the melting point of lead is only 327.46 C. In addition, the addition of other refractory metals to the composition of lead does not ensure a change in its ductility.

Lead Ingots

Lead is absolutely unsuitable as a structural metal. The mechanical properties of the metal cannot boast of high performance:

• The hardness limit on the Brinell scale is 3.2-3.28 Nb;
• The ultimate strength in mechanical compression is achieved at a force of 50 MPa;
• The maximum tensile strength is only 13 MPa.

The metal also has low thermal conductivity, it is almost 2 times lower than that of iron and 11 times lower than that of copper - 33.5 W/(m*K). The heat capacity of the metal at 20 degrees is 0.128 kJ/(kg*K).

Lead is not the best conductor of electricity - the resistivity is 0.22 Ohm/mm2.

But regarding corrosion resistance, although it does not belong to noble metals, it is quite high. Lead in its pure form, without an oxide film, remains at a temperature of 850 degrees, so the protective oxide film on the metal acts as the main obstacle to corrosion.

Under normal conditions, the metal is practically invulnerable to ordinary sources of corrosion, but in dilute nitric acid with a concentration of less than 70% it is quickly destroyed. Although it is neutral to sulfurous, acetic, hydrofluoric and phosphoric acid. Another substance that destroys the oxide film on metal is sulfuric (90%) acid. When contacting other metals, the corrosion process begins under normal conditions, although such a reaction does not occur with iron and copper.

Features of lead melting

High specific density, plasticity and ease of processing allow processing at home. The most common process for working with lead is smelting.

It is possible to reach the melting point of lead at 327.46 degrees even with the help of a fire, especially since this procedure does not require special structures or special technology. At the same time, even after heating lead to the required temperature, it will not be possible to make a casting from it immediately, if you do not know the features of the melting and casting technology.

Melting lead at home

Preparation for the process

Preparation for lead smelting involves equipping the place where the work will be carried out and the tools for the work. The ideal option for this would be a workshop with a forge or gas burner, which will create the necessary heat of melting the metal. It is recommended to use a melting spoon with a long handle as a tool. The melting boat must have a wide neck with a spout for draining liquid metal.

A wide neck is necessary to remove films of oxides and slags from the surface. For casting molds, it is recommended to place a place for the molds near the forge, so that the melting spoon is not far away.

It is recommended that the room be cleared of unnecessary objects before work, so that the working space allows you to approach the forge from any side. One of the important conditions for work is compliance with safety measures - the room must have good lighting and ventilation.

Tools for work include pliers, long-handled pliers, a test spoon, a metal rod for stirring the metal, and a rod with a spatula for adding metal to the melting container. What other tool will be needed, you need to decide before starting work, so as not to waste precious time until the metal has hardened.

Lead melting crucible

Security measures

When working with molten metal, it is imperative to protect the skin from thermal burns. During work, be sure to wear fireproof gloves and cloth or linen clothing that can withstand the ingress of molten substances.

In addition, it is necessary to wear a respirator or gauze bandage to protect the respiratory system - lead is a toxic substance.

So, by following these tips and using the information about the melting process, it won't be much of a problem to cast a fishing sinker or melt down the remains of an old battery into one ingot.

Source: https://1nerudnyi.ru/plavlenie-svintsa-osobennosti-protsessa-plavki-metalla-i-pravila-bezopasnosti/

Melting point of lead

Lead is a silvery-gray substance with a blue tint. In Mendeleev's periodic table of elements, the metal occupies 82nd place. Lead is designated by the abbreviation Pb (Latin: Plumbum).

Historical information

The chemical element has been known to people since ancient times. One of the first methods of metal extraction mastered by man was the smelting of lead. The first archaeological finds confirming this were lead beads found from the times of Çatalhöyük (modern Turkey). The items date back to 6400 BC.

The oldest lead figurine of a girl in long clothes was excavated in Egypt. It dates back to the time of the first dynasty of the pharaohs (3000 BC).

Lead pipes made up the ancient Roman water supply system. In the Ancient Roman Empire, up to 80 thousand tons of this metal were smelted annually. In Rus', since ancient times, lead has been used as roofing for cathedrals and churches.

Since time immemorial, the low melting point of lead has made it possible to obtain the metal and manufacture products of any shape from it.

Note! Over the course of 20 years, the Industrial Revolution since 1840 has raised the volume of annual lead smelting in the world from 100 to 250 thousand tons per year.

origin of name

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The Latin name of the metal Plumbum comes from the English expression plumber (plumber), which shows a connection with the lead water supply of Ancient Rome. Among the Slavic peoples there are such names as olivo, olevo and volava. In the Baltic countries, the name of the metal is more similar to the Russian name - swins and svinas.

Being in nature

Methods for soldering LED strips

Plumbum is usually not found in its pure form. It is found in more than 100 different minerals in the form of intermetallic agglomerates. Lead is present in uranium and thorium veins. Large accumulations of lead-zinc ores have been discovered and are being developed in Transbaikalia and the Primorsky region. Lead is mined in various deposits in the Urals and Norilsk.

The largest deposit with a high content of lead is located in the uranium ores of the Kohistan Ladakh arc (northern Pakistan).

Receipt

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The raw materials for lead extraction are rocks that include helenite. The heavy metal smelting process consists of several phases. From the initial raw material, a concentrate containing from 40 to 70 percent plumbum is isolated by flotation. Next, manufacturers take different paths.

One of the ways to transform the product into werkbley (blank lead) is smelting using the regeneration method. Another method is that the metal is restored from the oxide by melting the raw material in a water jacket heater.

The resulting werkley containing 90% lead is purified from copper. Then arsenic and antimony are removed by alkaline refining. Then silver and zinc are isolated. The effects of magnesium and calcium exclude bismuth. As a result, lead with a purity of 99.8% is obtained.

Global lead production based on research by international organizations for 2005

Country of originVolume, kilotons

Countries of Europe	2220
China	1430
Russian Federation	1120
South Korea	650
Kazakhstan	570
Ukraine	410

Technological properties and characteristics

The characteristics of the metal can be represented by the list:

• Lead density and mass;
• Lead smelting temperature;
• Mechanical properties;
• Corrosion resistance.

Lead density and mass

The density of the metal is 11342 kg/m3. This means that a metric cube of lead weighs 11.342 tons. Its large specific gravity allows it to be used as payloads in various devices.

Mechanical properties

The chemical element has softness and ductility, which allows cold rolling to achieve the state of thin foil. Cold deformation does not affect the change in mechanical properties.

Corrosion resistance

The chemical inertness of the element is close to that of noble metals. In the air, plumbum practically does not corrode. The rapidly forming oxide film on the surface of lead puts an insurmountable barrier to corrosion processes.

Aggressive environments for lead are hydrogen sulfide, coal anhydrite and sulfuric acid. Under their influence, the metal is actively destroyed.

Home and industrial methods

Without tin-lead solders (PLS), the existence of such an industry as radio engineering is impossible. Many industrial products contain POS coatings.

Melt preparation and pouring

In industrial conditions, the melt is prepared in special crucibles, which are placed in electric furnaces (equipment equipped with electronic measuring equipment that maintains the desired melting mode).

In radio engineering production, special heating baths are used to prepare solder for printed circuit boards of radio circuits.

In workshops and at home, solder is melted with a soldering iron tip. To prepare a large volume of molten metal, it is placed in a copper vessel on an electric stove. The alloy in the form of scrap is loaded into the melting bath gradually, as the next layer of metal melts.

Fishing varnishes

Avid fishermen at home cast fishing sinkers and spoons by pouring molten tin into clay molds. The spoons are then coated with waterproof varnishes.

Interesting. Fishing varnish is used to protect against the appearance of oxides on various figurines and other products.

Methods for getting rid of oxide

When exposed to air, lead products become covered with an oxide film. This is the result of the ionic interaction of oxygen and lead atoms. The oxide becomes not only protection against an aggressive environment, but also a barrier to electric current.

Important! Mechanical cleaning will not bring the desired result. The film will recover quite quickly. Sunflower oil, graphite grease or varnish can help get rid of oxides.

At home, the product is placed in a vessel with sunflower oil for about five minutes. After which it is removed from the vessel and allowed to dry.

In industrial conditions, graphite lubricant is used. The lead surface treated with the product retains its shiny appearance for a long time.

Lead melts at 327 degrees

Melting lead is not difficult. This can be done even at home using a suitable thin-walled steel or even aluminum container. The melting point of lead is low. To achieve it, a flame from a burner on a household gas or electric stove is sufficient.

At what temperature does lead melt? Temperature and characteristics of lead melting. Technological properties and characteristics of metal – Pravsila

Lead is a metal that can also be considered one of the metals known since ancient times. It is believed that its smelting was the first metallurgical process in human history. Over the past millennia, lead was used little, then again “came into fashion,” but was never forgotten.

The reason for this is its interesting qualities. And today we will study the physicochemical, mechanical and magnetic properties, technical characteristics of lead, its alloys and oxides, review photos of the element and give useful tips on its use.

Lead is a typical metal, heavy, dense, and has a bluish-gray color. The shine quickly disappears in air, as the metal is covered with a protective oxide film. Lead is quite common and easily mined, which explains its long-standing popularity.

With high density, the metal remains soft: at a temperature of 20 C it is easily scratched with a fingernail. Lead is malleable, but due to its not very presentable appearance and rapid loss of shine, it is very rarely used for the manufacture of decorative items. In ancient times, both jewelry and dishes were made from it.

This video is devoted to the study of the properties and characteristics of lead in chemistry and physics:

The molecular weight of the element is 82, which already indicates a decent severity of the substance. The crystal lattice is face-centered cubic: a metal atom is located in the corner of the cube and in the center of each face.

The substance belongs to the category of heavy metals. Density decreases as temperature increases:

• three temperatures at 20 C, the density is 11.34 g / cubic cm;
• at 327.6 C m10, 686 g/cubic. cm;
• at 650 C – 10.302 g/cc;
• at 850 C – 10.078 g/cc. cm.

The mass of lead is calculated based on the density, size of the sample and taking into account the temperature. The latter is important when smelting metals.

Next, let's talk about the casting properties of lead.

Melting, casting and boiling points

Despite its density, lead is not a refractory substance, and its addition to alloys does not provide this property. The metal is soft and ductile, easily rolled into very thin foil.

• Melting point – 327.46 C.
• Boiling point – 1749 C.
• Casting temperature – 400–450 C.
• At temperatures below 7.26 K, lead becomes a superconductor.

When melted, the metal becomes fluid; in the casting range, its viscosity rises from 1.89 to 1.23 MPa*C-2. Surface tension in the same range varies from 4.4 to 4.0 kN/m.

Mechanical characteristics

With high ductility, the metal does not have adequate strength characteristics:

• tensile strength is 12–13 MPa;
• compressive strength – 50 MPa;
• Brinell hardness – 3.2–.8 HB;
• elongation is 50–70%.

Cold hardening or cold hardening is a deformation compaction that does not increase the mechanical strength of the metal: the point is the low recrystallization temperature.

Thermal conductivity

This indicator for the metal is small: approximately 2 times less than iron and 11 times less than copper:

• thermal conductivity – 33.5 W/(m K);
• heat capacity at normal temperature – 0.128 kJ/(kg K).

This video will continue the story about the properties of lead:

The thermal and electrical conductivity of metals correlate quite well with each other. Lead is not a very good conductor of heat and is not one of the best conductors of electricity either: the resistivity is 0.22 Ohm-sq. mm/m with a resistance of the same copper of 0.017.

Corrosion resistance

Lead is a base metal, but its level of chemical inertness is close to that. Low activity and the ability to be covered with an oxide film determines decent corrosion resistance.

In a humid, dry atmosphere, the metal practically does not corrode. Moreover, in the latter case, hydrogen sulfide, carbonic anhydride and sulfuric acid - the usual “culprits” of corrosion, do not affect it.

Corrosion indicators in different atmospheres are as follows:

• in urban (smog) – 0.00043–0.00068 mm/year,
• in sea (salt) – 0.00041–0.00056 mm/year;
• rural – 0.00023–.00048 mm/year.

There is zero exposure to fresh or distilled water.

• The metal is resistant to chromic, hydrofluoric, concentrated acetic, sulfuric and phosphoric acid.
• But in diluted acetic or nitrogen with a concentration of less than 70%, it quickly collapses.
• Concentrated – more than 90% – sulfuric acid also acts in the same way.

Gases - chlorine, sulfur dioxide, hydrogen sulfide have no effect on metal. However, under the influence of hydrogen fluoride, lead corrodes.

Its corrosive properties are affected by other metals. Thus, contact with iron and copper has no effect on corrosion resistance, and the addition of bismuth or zinc reduces the substance’s resistance to acid.

Toxicity

Both lead and all its organic compounds are classified as chemically hazardous substances of class 1.

The metal is very toxic, and poisoning is possible during many technological processes: smelting, production of lead paints, ore mining, and so on.

Not so long ago, less than 100 years ago, household poisoning was no less common, since lead was even added to white face wash.

The greatest danger is posed by metal vapors and dust, since in this state they most easily penetrate the body. The main route is the respiratory tract. Some can be absorbed through the gastrointestinal tract and even skin through direct contact - the same lead white and paints.

• Once in the lungs, lead is absorbed by the blood, distributed throughout the body and accumulates mainly in the bones. Its main toxic effect is associated with disturbances in the synthesis of hemoglobin. Typical signs of lead poisoning are similar to anemia - fatigue, headaches, sleep and digestive disorders, but are accompanied by constant aching pain in the muscles and bones.
• Long-term poisoning can cause “lead paralysis.” Acute poisoning provokes an increase in pressure, hardening of blood vessels, and so on.

Treatment is specific and long-term, since it is not easy to remove heavy metal from the body.

We will discuss below what environmental properties lead has.

Lead pollution of the environment is considered one of the most dangerous. All products that use lead require special disposal, which is carried out only by licensed services.

Unfortunately, lead pollution is caused not only by the activities of enterprises, where it is at least regulated. In city air, the presence of lead vapor ensures the combustion of fuel in cars. Against this background, the presence of lead stabilizers in such familiar structures as a metal-plastic window no longer seems worth attention.

Lead is a metal of industrial importance. Despite its toxicity, it is used too widely in the national economy for the metal to be replaced with anything.

This video will tell you about the properties of lead salts:

Source: https://pravsiila.ru/pri-kakoj-temperature-plavitsja-svinec-temperatura-i-osobennosti-plavlenija-svinca-tehnologicheskie-svojstva-i-harakteristiki-metalla.html