What does white phosphorus interact with? Phosphorus in nature and its industrial production

Prevalence in nature. Mass fraction phosphorus in the earth's crust is 0.08%. The most important naturally occurring phosphorus minerals are fluorapatite Ca5 (PO4) 3F and phosphorite Ca3 (PO4) 2.

Properties. Phosphorus forms several allotropic modifications, which differ markedly in properties. White phosphorus is a soft crystalline substance. Consists of P4 molecules. Melts at a temperature of 44.1 ° C. Let's very well dissolve in carbon disulfide CS2. Extremely poisonous and easily ignites.

When white phosphorus is heated, Red Phosphorus is formed. It is a mixture of several modifications that have different molecular lengths. The color of red phosphorus, depending on the method and conditions of production, can vary from light red to violet and dark brown. Its melting point is 585-600 °.

Black phosphorus is the most stable modification. By outward appearance it looks like graphite. Unlike white phosphorus, red and black phosphorus do not dissolve in carbon disulfide, they are not poisonous or flammable.

Phosphorus is chemically more reactive than nitrogen. The chemical activity of phosphorus depends on allotropic modification in which it is located. So, the most active white phosphorus, and the least active is black phosphorus.

In equations chemical reactions white phosphorus is usually written with the formula P4, which corresponds to the composition of its molecules. The red and black modifications of phosphorus are usually written by the formula P. The same symbol is used if the modification is unknown or can be any.

1. Interaction with simple substances - non-metals. Phosphorus can react with many non-metals: oxygen, sulfur, halogens, phosphorus does not react with hydrogen. Depending on whether there is an excess or deficiency of phosphorus, phosphorus compounds (III) and (V) are formed, for example:

2P + 3Br2 = 2PBr3 or 2P + 5Br2 = 2PBr5

2. Interaction with metals. When phosphorus is heated with metals, phosphides are formed:

3Mg + 2P = Mg3P2

Phosphides of some metals can be decomposed by water to form phosphine gas PH3:

Mg3P2 + 6H2O = 3Mg (OH) 2 + 2PH3

Phosphine PH3 by chemical properties similar to ammonia NH3.

3. Interaction with alkalis. When white phosphorus is heated in an alkali solution, it disproportionates:

P4 + 3NaOH + 3H2O = PH3 + 3NaH2PO2

Receiving... Phosphorus is industrially obtained from calcium phosphate Ca3 (PO4) 2, which is isolated from phosphorites and fluorapatites. The preparation method is based on the reduction reaction of Ca3 (PO4) 2 to phosphorus.

Coke (carbon) is used as a reducing agent for phosphorus compounds. To bind calcium compounds, add to the reaction system quartz sand SiO2. The process is carried out in electric furnaces (production is referred to as electrothermal). The reaction proceeds according to the equation:

2Ca3 (PO4) 2 + 6SiO2 + 10C = 6CaSiO3 + P4 + 10CO

The reaction product is white phosphorus. Due to the presence of impurities, technical phosphorus has yellow, therefore, in the industry it is called yellow phosphorus.

Phosphate fertilizers. Phosphorus, like nitrogen, is important element to ensure the growth and life of plants. Plants extract phosphorus from the soil, so it must be replenished by periodically adding phosphate fertilizers... Phosphate fertilizers are produced from calcium phosphate, which is part of natural phosphorites and fluorapatites.

The simplest phosphoric fertilizer - phosphate rock is ground phosphorite Ca3 (PO4) 2. This fertilizer is difficult to dissolve, it can be absorbed by plants only on acidic soils.

The action of sulfuric acid on calcium phosphate produces a simple superphosphate, the main component of which is calcium dihydrogen phosphate Ca (H2PO4) 2. It is a soluble substance and is well absorbed by plants. Method of obtaining simple superphosphate based on reaction

Ca3 (PO4) 2 + 2H2SO4 = Ca (H2PO4) 2 + 2CaSO4

In addition to the main component, superphosphate contains up to 50% calcium sulfate, which is a ballast. To increase the phosphorus content in the fertilizer, phosphorite is treated with phosphoric acid:

Ca3 (PO4) 2 + 4H3PO4 = 3Ca (H2PO4) 2

The resulting fertilizer is called double superphosphate. Another phosphorus fertilizer with a high phosphorus content is CaHPO4 2H2O precipitate.

Highly concentrated phosphorus fertilizers are prepared on the basis of super phosphoric acid- mixtures of polyphosphoric acids H4P2O7, H5P3O10, H6P4O13, etc. These acids are formed when phosphoric acid H3PO4 is heated in vacuum.

When polyphosphoric acids interact with ammonia, ammonium polyphosphates are formed, which are used as complex nitrogen-phosphorus fertilizers.

Together with nitrogen, phosphorus is part of some other complex fertilizers, for example, ammophos NH4H2PO4 and diammophos (NH4) 2HPO4.

PHOSPHORUS(Phosphorus) - chemical element 15 (Va) groups Periodic table, atomic number 15, atomic mass 30.974. There are 23 known phosphorus isotopes 24 P - 46 P, among them one stable 31 P, and only it occurs in nature. The half-life of the isotope 30 P is 2.55 minutes; this is the first radioactive isotope produced artificially in 1934 Frederick and Irene Joliot-Curie.

It is possible that phosphorus in its elementary form was obtained as early as the 12th century. by the Arab alchemist Alhid Behil during the distillation of urine with clay and lime, this is evidenced by an ancient alchemical manuscript kept in the Paris Library. However, the discovery of phosphorus is usually attributed to the ruined Hamburg merchant Hennig Brand. The entrepreneur was engaged in alchemy in order to obtain the philosopher's stone and the elixir of youth, with the help of which one could easily improve his financial situation. After evaporation of 50-60 buckets of urine (he took it in the soldiers' barracks) for two weeks and the subsequent strong calcination of the dry residue with coal and sand in the retort, Brand succeeded in 1669 to condense the emitted vapors under water and obtain a small amount of a yellow substance. It glowed in the dark and was therefore called by Brand "cold fire" (kaltes Feuer). Brand's contemporaries called this substance phosphorus because of its ability to glow in the dark (ancient Greek jwsjoroV). In general, since ancient times, all substances capable of emitting light in the dark have been called "phosphorus". So, the widely known "Bologna phosphorus" - barium sulfide.

In 1682 Brand published the results of his research, and now he is rightly considered the discoverer of element No. 15. Phosphorus was the first element, the discovery of which is documented, and its discoverer is known.

The interest in the new substance was tremendous, and Brand took advantage of this - he demonstrated phosphorus only for money or exchanged small amounts of it for gold. Despite numerous efforts, the Hamburg merchant could not fulfill his cherished dream - to obtain gold from lead with the help of "cold fire", and therefore he soon sold the recipe for the new substance to a certain Kraft from Dresden for two hundred thalers. The new owner managed to amass a much larger fortune on phosphorus - with a "cold fire" he traveled throughout Europe and demonstrated it to scientists, high-ranking officials and even royalty, for example, Robert Boyle , Gottfried Leibniz, Karl the Second. Although the method of preparing phosphorus was kept in the strictest confidence, in 1682 Robert Boyle managed to get it, but he also announced his method only at a closed meeting of the Royal Society of London. Boyle's method was made public after his death, in 1692.

For a long time, phosphorus was not counted simple substance, and only in the 1770s did the French chemist Antoine Laurent Lavoisier in his works devoted to the study of the composition of air, he was able to firmly establish that phosphorus is an elementary substance.

Phosphorus in nature and its industrial production.

The phosphorus content in the earth's crust is estimated at 8 10 -2% by weight. Phosphorus is the eleventh most abundant element on Earth and is one of the twenty most abundant elements. Solar system... Element 15 is found in many types of meteorites (stone and iron-stone) and on the Moon. For example, in iron meteorites, the phosphorus content fluctuates in the range of 0.02-0.94% (wt.), And in various samples lunar soil it is 0.05-0.32% (mass). Despite the fact that geologists classify phosphorus as an impurity element (in the rocks of most of the earth's crust, its content is only 0.1%), it is rock-forming, since some rocks are composed almost entirely of phosphate minerals. In a free state, phosphorus does not occur on earth and exists in the lithosphere for almost the highest degree oxidation, in the form of orthophosphate ion PO 4 3-. More than two hundred minerals are known that contain phosphorus in significant (more than 1%) amounts. Phosphate deposits are generally classified into three groups: apatite deposits, sedimentary phosphorites, and guano deposits.

Apatity- a kind of phosphorites, they can be of both magmatic and marine (sedimentary) origin. This name was given to a group of minerals about two hundred years ago, and translated from Greek means "deceptive" (ap át án), originally the so-called mineral, which was often confused with aquamarine, amethyst or olivine. Apatite minerals are represented by fluorapatite Ca 5 (PO 4) 3 F (industrially the most significant), hydroxyapatite Ca 5 (PO 4) 3 (OH) and chlorapatite Ca 5 (PO 4) 3 Cl, francolite (a type of carbonate apatite) (Ca, H 2 O) 10 (F, OH) 2 (PO 4, CO 3) 6, wilkeite Ca 10 (OH) 2 (PO 4, SiO 4, SO 4) 6, pyromorphite Pb 10 Cl 2 (PO 4, AsO 4) 6 and many others. The largest deposits of magmatic apatite are located in Russia, countries South Africa(alkaline complex of Palabor), Uganda and Brazil. The world's largest magmatic apatite deposit, the Khibiny massif of nepheline syenites, lies on the Kola Peninsula, near Kirovsk. It was opened in 1926 by a group of scientists led by Academician A.E. Fersman.

Most of the world's phosphorus reserves are marine(sedimentary)phosphorites and products of their weathering. It is assumed that they are of oceanic origin. In coastal regions of the trade wind belt for long period there was a deposition of phosphates due to various organic and inorganic processes. The phosphorite concentration in the deposit increased as a result of the slow accumulation of phosphates from environment... The largest deposits of sedimentary phosphorites are owned by Morocco (70% of the world's phosphate reserves) and Western Sahara, USA, China, Tunisia, Kazakhstan.

Guano (Spanish guano) - natural sediments formed during the decomposition of the bones and excrement of seabirds (cormorants, boobies and pelicans), sometimes guano deposits reach one hundred million tons. Guano has been known since time immemorial, as early as 200 BC. the ancient Carthaginians used bird droppings as fertilizer. In the late 19th - early 20th century. the "Bird Islands" of Peru were discovered, so named because of a large number(about 20 million) seabirds living there. In those days, the Peruvian government received real income from attracting large numbers of tourists to the Bird Islands and from the sale of huge quantities of guano as fertilizer. In the past forty years, due to the activities of Peruvian fishermen, the population of guana-producing birds has sharply decreased (4 times), so that some of the Peruvian "Bird Islands" are now generally empty. The largest deposits of guano are located along the coast of Africa, South America, California, Seychelles. The highly decomposed guano consists mainly of monetite CaHPO 4 and vitlockite b-Ca 3 (PO 4) 2.

World mining(2002) phosphate is 135 million tons annually. The world's largest phosphate producer is the United States (26% of world production). Development is ongoing in Florida (Bone Valley formation), North Carolina, Idaho and Utah. The Kingdom of Morocco (together with Western Sahara) is the second largest producer of phosphate ore (17.3%) and the largest exporter. Phosphorites are mined in three regions: Kuribge, Yussufii and Ben-Gerir. The main deposit (Khouribga) is located 120 km south of Casablanca. The total reserves of phosphorites in Morocco are 64 billion tons, explored 10 billion tons (60% of the world's proven reserves). In third place in terms of production is China (16.7%), in fourth - Russia (10.5%). The main source of phosphorus raw materials in Russia is apatite-nepheline ore on the Kola Peninsula. For more than seventy years that have passed since the discovery of the field, more than 570 million tons of apatite concentrate have been produced. Currently, 10 deposits have been explored within the Khibiny massif, the total reserves of which are 3.6 billion tons, and in general on the Kola Peninsula ore reserves are about 20 million tons. Considering that over the past time, less than 1.5 billion tons have been mined, the reserves of apatite in Russia should be sufficient for many more years.

Usually, an industrial deposit is considered to be at least 6,000 tons of phosphate rock per hectare. In open pits, phosphate is extracted by scraper excavators. Sand deposits and waste rock are removed first, and then the phosphate ore is recovered. From quarries to concentration plants, ore can be supplied (over distances of several kilometers) along steel pipes in the form of an aqueous slurry.

In seawater, all inorganic phosphorus is found only in the form of orthophosphate anion. The average concentration of phosphorus in seawater is very low and amounts to 0.07 mg R / liter. The phosphorus content is high in the Andaman Islands region (about 12 μmol / l). The total oceanic amount of phosphorus is estimated at 9.8 · 10 10 tons.

Phosphorus is completely absent in the Earth's atmosphere.