The use of ferrous sulfate from ancient times to today, features of application, interesting facts and useful tips

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Ferrous sulfate is a chemical substance that is a salt of sulfuric acid and divalent iron. When combined with seven molecules of water, a compound is formed, which in everyday life is called iron sulfate.

This chemical compound also has various other names under which it is sold and used in various fields - ferrous sulfate, ferrous sulfate, iron sulphate, iron(II) tetraoxosulfate, iron(II) sulfate.

In nature, iron sulfate has an analogue - a mineral called melanterite.

Iron sulfate was discovered by mankind a long time ago; methods of its use are contained in ancient Greek texts dating back one and a half thousand years. Today it is used in various fields of industry, medicine, veterinary medicine, and agriculture. The scope of its use in various industries is extremely wide, so below we will list those areas where it is used very often, and its replacement with other analogues worsens the quality of the medicine or product.

Qualitative characteristics of ferrous sulfate

The quality of iron sulfate is determined according to the standards established by GOST 6981-084 Regarding the physical and chemical characteristics for industrially produced iron sulfate for 1st grade mass fraction:

• ferrous sulfate should be at least 52%;
• free sulfuric acid should be no more than 0.3%;
• substances that do not dissolve in water should not exceed 0.2%.

For the second grade, mass fraction:

• iron sulfate should be at least 47%;
• free sulfuric acid should be no more than 1%;
• substances that do not dissolve in water should not exceed 1%.

see also

Application in agriculture

In agriculture, ferrous sulfate is used for:

• chemical reclamation of various soils;
• for the destruction of lichens and mosses;
• as a drug that successfully destroys spores of various fungi;
• to combat slugs and other pests of garden and forest plantings;
• treatment of plants suffering from chlorosis.

Also in agricultural farms, ferrous sulfate is used to increase the productivity of growing green mass, since the substance is one of the components of many oxidative enzymes, which play an important role in plant respiration processes. Iron sulfate is used as a fertilizer when there is a lack of iron in the soil.

Good results are obtained by foliar feeding of currants and strawberries with an aqueous solution of ferrous sulfate, prepared at a rate of five to ten grams of the drug per ten liters of water.

Iron sulfate is often used in combination with organic fertilizers, adding a mixture of one hundred grams of iron sulfate and ten kilograms of organic matter to the soil.

Those involved in viticulture are well aware of the beneficial qualities of ferrous sulfate. In spring, spraying the soil around the vines with a solution of this substance destroys fungi and bacteria, and the effect on the vines themselves slows down the development of buds, which helps the plant more easily tolerate early frosts. Cuttings of vines are also treated with iron sulfate - they take root and germinate better.

Do not treat grapevine leaves with iron sulfate solution - the solution can cause burns.

Iron sulfide is also used to treat pome garden trees to destroy harmful lichens, mosses, and insects. To do this, prepare a solution at the rate of 500 grams of vitriol per ten liters of water. For shrubs, as well as for stone fruits, the concentration is slightly lower - three hundred grams per ten liters of water.

It is important to remember that treatment with iron sulfate should not be allowed if treatment with lime was carried out - in these cases, copper sulfate is used.

Ferrous sulfate is effective in treating chlorosis - for this, a solution is added to the soil around the vine at the rate of one gram of ferrous sulfate, twenty grams of ascorbic or citric acid per ten liters of water. To combat chlorosis of hydrangeas and other flowers, use a solution of thirty grams of iron sulfate per ten liters of water and spray the diseased plants at intervals of six days until complete recovery.

Ferric sulfate is also used in veterinary medicine. When feeding piglets and calves.

Moisturizes [edit]

Iron(II) sulfate can occur in a variety of hydration states, and some of these forms exist in nature.

• FeSO 4 H 2 O (mineral: Szomolnokite, [7] relatively rare)
• FeSO 4 4H 2 O (mineral: rosenite,[8][30] white, relatively common, may be a dehydration product of melanterite)
• FeSO 4 5H 2 O (mineral: Siderotyl, [1] [31] relatively rare)
• FeSO 4 6H 2 O (mineral: ferrohexahydrite, [2] [32] relatively rare)
• FeSO 4 7H 2 O (mineral: melanterite,[9][33] blue-green, relatively common)

Anhydrous iron(II) sulfate

The tetrahydrate is stabilized when the temperature of aqueous solutions reaches 56.6 °C (133.9 °F). At 64.8 °C (148.6 °F), these solutions form both tetrahydrate and monohydrate. [4]

All of these mineral forms are associated with oxidation zones of iron-containing ore strata (pyrite, marcasite, chalcopyrite, etc.) and associated environments (for example, sources of coal fires). Many undergo rapid dehydration and sometimes oxidation. In such environments, many other, more complex (basic, hydrated and/or containing additional cations) Fe(II)-containing sulfates exist, a good and common example being copiapite. [34]

Use of ferrous sulfate in medicine

In pharmaceuticals, preparations using ferrous sulfate are classified into two clinical and pharmacological groups:

• hematopoiesis stimulants;
• preparations containing micro- and macroelements.

Used for the treatment of iron deficiency anemia, as antianemic drugs in case of iron deficiency for the normal process of creating myoglobin, hemoglobin, and some enzymes in the hematopoietic organs to stimulate erythropoiesis.

Ferrous sulfate has been used in medicine since ancient times. It was used to treat “pale sickness” in Rus', the ancient Greek physician Melampas treated Crown Prince Iphiclas Tesalius with it one and a half thousand years ago, Ibn Sina used it to combat pathological thinness and to improve complexion, as a tonic for dropsy, Paracelsus recommended. At the beginning of the 19th century, the best remedy for the treatment of “pale sickness”, anemia, and general weakness were considered to be Blodian pills, proposed by the French physician Pierre Blaud - they consisted of ferrous sulfate and potassium carbonate.

Today, preparations with ferrous sulfate are used for diseases such as

• deficiency anemia;
• breastfeeding period;
• secretory insufficiency in chronic gastritis;
• period of active growth;
• pregnancy;
• malnutrition;
• after gastrectomy;
• duodenal ulcer;
• stomach ulcer;
• prematurity in children;
• decreased body resistance;
• bleeding and blood loss.

Although ferrous sulfate preparations are sold in pharmacies without a prescription, there are still some restrictions on their use. Among the contraindications:

• hemochromatosis;
• hypersensitivity;
• hemosiderosis;
• late porphyria of the skin;
• thalassemia;
• chronic hemolysis;
• gastrointestinal diseases that interfere with iron absorption;
• sideroblastic anemia;
• hemolytic and aplastic anemia;
• various anemias that are not associated with iron deficiency.

The drugs are prescribed to patients, especially children, in dosages taking into account the conversion to active iron.

Medicines containing ferrous sulfate should not be prescribed for frequent blood transfusions.

Medicines using iron are presented in the table.

It is interesting to note that the properties of ferrous sulfate in improving the transfer of oxygen from the blood to the muscles have aroused interest in this substance from sports medicine. However, a thorough study of athletic performance by athletes who used the drug as a dietary supplement did not reveal its effectiveness.

A new generation of iron preparations – iron bisglycinate (chelate)

Anemia prevalence

The significance of anemia as a problem in the modern world is beyond doubt. Despite all the achievements of civilization, iron deficiency is the main and most common nutritional disorder in the world. Iron deficiency, which affects many children and women in developing countries, is the only type of nutritional deficiency that is also common in developed countries. Its prevalence levels are staggering: 2 billion people, more than 30% of the world's population, suffer from anemia.1

According to the World Health Organization, the most vulnerable groups for the development of anemia are pregnant women, women of reproductive age, children and the elderly. Moreover, the highest percentage of occurrence is among women of reproductive age - 30%.

Among anemias, the leading ones are iron deficiency, accounting for up to 90% in women and up to 80% among men. Important is the high prevalence of latent iron deficiency among the population, which ranges from 19.5% to 30%; in addition, from 50% to 86% of women have risk factors for anemia.

Iron deficiency anemia (IDA) is a disease of the blood system caused by iron deficiency in the body, accompanied by changes in the parameters of its metabolism, a decrease in the concentration of hemoglobin in erythrocytes, their quantitative and qualitative changes and is clinically expressed by anemic hypoxia and sideropenia.

Sideropenia and subsequent tissue and hemic hypoxia lead to disorders of the cardiovascular (myocardial dystrophy and circulatory disorders of varying degrees), nervous system (vegetative-vascular, vestibular disorders, asthenic syndrome), decreased reproductive function of women, as well as the development of complications during pregnancy and childbirth, changes in intelligence and behavioral moods, chronicity of various diseases and, as a consequence, decreased performance and deterioration in quality of life.4

The evolution of synthetic drugs for the treatment of iron deficiency anemia

Pharmacotherapy of IDA is based on the introduction of iron into the body from iron-containing drugs. The choice of a drug for the correction of sideropenia is given special importance, since not only effectiveness is important, but also the absence of adverse reactions and complications during their use.

There is a conditional division of iron preparations into divalent and trivalent. However, the valency of iron itself does not represent any value.

It is known that the absorption of iron in the intestine is possible only when the microelement is in a divalent form, which is able to pass through the cell membrane of the intestinal mucosa. The low pH value of gastric contents promotes the dissolution of alimentary iron and the transition of ferric iron (oxide) to the divalent form (ferrous).17

When gastric contents enter the intestine, the pH of the bolus increases and, unlike ferro-ion (Fe2+), ferri-ion (Fe3+) forms insoluble salts. Under these conditions, only mucin, by chelating iron, is able to maintain ferri ion in a soluble state.4

Thus, iron compounds in preparations must have good solubility, high bioavailability, sufficient elemental iron content and low toxicity. Let us consider the absorption features of each of the three known groups of iron preparations.

First generation of iron supplements

One of the first groups of iron preparations began to use ionic salts of divalent iron. This group is characterized by a fairly rapid onset of effect in terms of increasing hemoglobin and improving hemodynamic parameters in peripheral blood.

However, treatment with ionic iron preparations, in particular ferrous sulfate, causes adverse reactions in 44.7% of patients. The gastrointestinal tract (GIT) is most often affected. Symptoms of dysfunction of its upper sections usually appear within an hour after taking the medicine and can occur in either mild form (nausea, epigastric discomfort) or severe form - with abdominal pain and/or vomiting. In addition, ferrotherapy with iron salt preparations is often accompanied by the appearance of a metallic taste during the first days of treatment, darkening of tooth enamel and gums, and diarrhea or constipation are also possible. It is well known that iron salt preparations in the intestinal lumen interact with food components and medications, complicating the absorption of iron. In this regard, they are recommended to be prescribed 1 hour before meals, however, this increases the damaging effect of Fe2+ compounds on the intestinal mucosa, up to the development of its necrosis.5

The cause of these side effects is the hydrolysis of iron salts in the stomach. Under the influence of gastric juice, ionic iron salts undergo hydrolysis (dissociation) in the stomach, as a result of which free iron molecules negatively affect the gastrointestinal mucosa and provoke side effects: nausea, abdominal pain, metallic taste in the mouth, diarrhea/constipation.

Second generation of iron supplements

Absorption of iron as iron-III hydroxide-polymaltose complex (HPC)

has a fundamentally different scheme compared to its ionic compounds and is carried out through active absorption with competitive exchange of ligands, the level of which determines the rate of absorption of iron Fe3+.
The nonionic structure, which ensures the stability of the complex and the transfer of iron using a transport protein, prevents the free diffusion of iron ions in the body, that is, pro-oxidant reactions. However, the bioavailability of polymaltose iron-III complex is the lowest
among all iron preparations, only 10–15%.

Due to the large size of the molecule (55 kDa), its passive diffusion is approximately 40 times slower

than that of iron ions.6 Such low bioavailability must be compensated for by large daily doses of CHP.

New generation of iron supplements - a new solution to the problem of anemia

Since the late 90s and early 2000s, the use of chelated iron complexes began to be actively introduced for the treatment of iron deficiency and anemia in humans. Although this group of drugs appeared much earlier, and were initially used as food additives and in veterinary medicine.

In 1893, Alfred Werner postulated a new molecular structure to characterize these stable molecules. A few years later, in 1920, Morgan and Drew applied the term "chelate" to the molecular structure postulated by Werner. 7

Small protein molecules are easier to digest, so the body combines inorganic minerals with amino acids to take advantage of the intestines' affinity for protein absorption. This binding process is called chelation (key-lay-shun).10

Metal chelates are complex compounds of a metal with an amino acid.

Unlike metal salts, the ligand in the chelate complex donates electrons to the cation, thereby making the molecule ionic neutral, stable

to various factors acting in the gastrointestinal tract (pH, food), and the low molecular weight
promotes maximum absorption of iron
when taken orally.8

Chelated complexes penetrate more easily

through the intestinal wall and
are better absorbed
without disturbing the ionic and mineral balance of the cell.10

Ferrous bisglycinate consists of one molecule of iron, which is connected to the carboxyl groups of two molecules of glycine using covalent bonds.

The ratio of iron to ligand 1:2 neutralizes the valence of iron, which ensures its resistance to various factors acting in the gastrointestinal tract (pH, food). Therefore, the chelate compound cannot be hydrolyzed in the stomach, is completely absorbed in the small intestine and, unchanged, enters the enterocytes, where the iron molecule is released.8

Iron bisglycinate

is a source of non-heme iron. After oral administration, the compound enters unchanged into enterocytes, where it is hydrolyzed into iron and glycine. The stability of the iron bisglycinate compound is due to the fact that it does not hydrolyze at different pH values, and its low molecular weight (204 g/mol) allows for maximum absorption of iron when taken orally.8

• Thus, free iron molecules are not formed in the gastrointestinal tract.
• The absence of contact of non-ionized iron with the gastric mucosa minimizes possible side effects.
• Ferrous bisglycinate can bind to two types of receptors: DMT-1 (located on the duodenal villi) and PEPT-1 (localized throughout the gastrointestinal tract).9
• This feature of the chelate significantly increases the level of iron absorption in the gastrointestinal tract, which is 3.4 times higher than that of ferrous sulfate, which interacts only with DMT1 receptors.9
• The ionic neutral molecule does not react with other nutrients or interfere with their absorption.10
• Celiac disease provokes the occurrence of iron deficiency. Ferrous bisglycinate is the only drug that effectively corrects iron deficiency in patients with celiac disease through a dual absorption mechanism: binding to the DMT-1 and PEPT-1 receptors.11
• The bioavailability of iron bisglycinate approaches 90–100%. 9

Multizan® Ferrum contains iron bisglycinate, a patented Ferrochel® complex from Albion Minerals, a world leader and innovator in the field of mineral amino acid chelate nutrition.

Albion®'s unique range of chelated minerals:

• Maximum absorption and easy digestion.
• Does not interact with other nutrients.
• Resistant to the acidic environment of the stomach (pH).
• Suitable for vegetarians.
• Kosher certified product.
• Gluten free and GMO free.
• The safety of ferrous bisglycinate has been recognized by the EFSA (European Food Safety Authority) and the FDA (Food and Drug Administration, USA).12

Even with increased bioavailability, iron bisglycinate is safe. Absorption is controlled by iron stores

in the body, with larger amounts typically absorbed by people with lower iron status.
A body suffering from iron deficiency anemia may consume 90% of the iron, while a body without iron deficiency anemia may consume only 10%, or exactly as much as the body needs to compensate for metabolic losses. Ferrochel® iron bisglycinate has been found to be 2.6 times safer
than ferrous sulfate and safer than conventional inorganic iron found in foods and dietary supplements.13

Comparative table of LD50 doses (the average dose of a substance that causes the death of half of the members of the test group) of various iron preparations when administered orally to white mice.14, 15, 16

• Ferrous bisglycinate has the best safety profile
• Acute oral LD50 of Ferrochel iron bisglycinate 2800 mg/kg body weight - the highest dose of any iron supplement
• No Observed Side Effect Level (NOAEL) is at least 500 mg per kg body weight

Multizan® Ferrum - highly effective and easily absorbed iron with excellent tolerability

Literature:

1. https://www. who. int/nutrition/topics/ida/ru/
2. WHO global database of anemia, 1993-2005
3. WHO meeting report. Preconception care to reduce maternal and childhood mortality and morbidity, 2012
4. “Medicines used for the prevention and treatment of iron deficiency conditions” Kruglov D. S. Novosibirsk State Medical University. "Scientific review. Medical Sciences" No. 4/2017
5. Gribakin S. G. The importance of baby food products fortified with iron in the prevention of iron deficiency anemia / S. G. Gribakin // Issues of modern pediatrics. — 2002. — vol. 1, No. 5. — pp. 52–56.
6. https://medi. ru/info/3878/ Maltofer
7. Stephen D. Ashmead The chemistry of ferrous bis-glycinate chelate Archivos Latinoamericanos de Nutrición ALAN v.51 n.1 supl.1 Caracas mar. 2001
8. DeWayne HA Arch. Latino Am. De Nutr., 2001, 51 (1), 7-12
9. Oscar Pineda, H. DeWayne Ashmead Effectiveness of Treatment of Iron-Deficiency Anemia in Infants and Young Children With Ferrous Bis-glycinate Chelate Nutrition 17:381–384, 2001
10. https://www. albionferrochel. com/index. php/iron-importance/ferrochel
11. M. Bertini, O. G. Shadrin “Correction of iron deficiency in children: expert opinion” 2018; https://health-ua.com/article/40109-korrektciya-defitcita-zheleza-u-detej-mnenie-ekspertov
12. https://www.albionminerals. com/human-nutrition/products-trade/mineral-applications/dietary-supplements
13. https://www.albionferrochel. com/index. php/effectiveness
14. Geisser et al., 1992; Forster et al., 1993.
15. Borzelleca, J, and Jeppsen, R., Food and Chemical Toxicology 37 (1999) 723-731 Safety evaluation of ferrous bisglycinate chelate
16. Toxicology and safety of Ferrochel and other iron amino acid chelates Latinoarm. Nutr. 2001 Mar;51(1 Suppl 1):26-34.
17. A. G. Rumyantseva, I. N. Zakharova “DIAGNOSTICS AND TREATMENT OF IRON DEFICIENCY ANEMIA IN CHILDREN AND ADOLESCENTS” Ministry of Health of the Russian Federation, study. manual, Moscow, 2015

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Use of iron sulfate in construction

This chemical has been used since ancient times to increase the durability of wooden buildings.

Since the ancient Greeks, people have been looking for materials that would help protect the wood of houses from rotting. They covered them with vegetable oils, then with various paints and varnishes. The effect was, at best, short-lived. Paints and varnishes peeled off and rotting processes quickly began to develop in these places.

The method of destroying bacteria and fungi that destroy wood using various chemicals turned out to be much more effective. Today this method is called biocidal. It is based on the impregnation of wood with impregnants (antiseptic solutions). Among the most effective impregnants is iron sulfate.

To protect wood, iron sulfate solution:

• applied to wooden surfaces with paint brushes;
• applied to wooden parts by spraying with a spray gun;
• wooden structures are completely immersed in a solution of iron sulfate, and to increase efficiency they are heated in the solution.

An even greater positive effect is achieved by the industrial treatment of wooden structures with iron sulfate. It is performed using one of the following methods:

• impregnated with a solution of ferrous sulfate in autoclaves;
• using diffusion impregnation, during which a layer of paste-like material is applied to wooden parts, which contains iron sulfate, which gradually penetrates into the material, completely saturating its structure.

In rural areas of the Scandinavian countries, an ancient special composition is still used today for painting houses and fences to protect them from rotting based on iron sulfate. Includes:

• water 9 liters;
• iron sulfate - 1.56 kilograms;
• flour – 0.72 kilograms;
• dry lime pigment – ​​1.56 kilograms;
• salt – 0.36 kilograms.

1/3 of the water is gradually introduced into the flour and stirred until a paste is obtained, which is filtered and then heated, constantly stirring thoroughly, and then salt, lime pigment and iron sulfate are added - after they are completely dissolved, the rest of the water is added, having preheated it.

If you want to give the paint any color, the appropriate pigments are added to it. Paint is applied to wooden surfaces without a primer and in two layers. The paint consumption in this case is 0.3 kilograms per square meter. The minimum service life of such surfaces under atmospheric conditions in Norway and the northern regions of Finland is twenty years.

The advantages of impregnations based on iron sulfate for builders include its good water solubility (a 25% solution can be prepared in cold water, and 55% in hot water), as well as the fact that such solutions do not corrode iron parts.

When using ferrous sulfate solutions as an antiseptic, safety precautions require that all work be performed with rubber gloves and a respirator.

In Russia, a method was invented and bandaged for the production of wood fiber and particle boards for the construction and furniture industry from wood materials containing cellulose and lignin through their step-by-step processing. At one stage, the main element of the complex technology is a modifying agent such as iron sulfate, which is introduced into wood pulp heated by steam at t=190°C, and then pressed into slabs at t=190°C.

Since this method does not use substances of a phenolic nature, environmentally friendly slabs of increased strength are obtained that are not subject to rotting processes and do not emit formaldehyde during operation. Such slabs are also easy to process, moisture resistant, and low in flammability.

The modifying additive of iron sulfate simultaneously significantly increases the strength of the tile material and shortens the time required for the manufacture of slabs. In the construction industry, iron sulfate is also used in the production of clinker mixtures, dry plasters, and cements to remove hexavalent chromium ions.

Production and reactions[edit]

In steel finishing, the steel sheet or rod is passed through pickling baths of sulfuric acid before being electroplated or coated. This treatment produces large amounts of iron(II) sulfate as a by-product. [35]

Fe + H 2 SO 4 → FeSO 4 + H 2

Another source of large quantities is the production of titanium dioxide from ilmenite using the sulfate process.

Ferrous sulfate is also produced on an industrial scale by oxidation of pyrite:

2 FeS 2 + 7 O 2 + 2 H 2 O → 2 FeSO 4 + 2 H 2 SO 4

It can be obtained by displacing metals less reactive than iron from solutions of their sulfates: CuSO 4 + Fe → FeSO 4 + Cu.

Reactions[edit]

When dissolved in water, iron sulfates form a metal 2+ aqua complex, which is an almost colorless paramagnetic ion.

When heated, iron(II) sulfate first loses its water of crystallization and the original green crystals turn into an anhydrous white solid. When heated further, the anhydrous material releases sulfur dioxide and white sulfur trioxide fumes, leaving reddish-brown iron(III) oxide. Decomposition of iron(II) sulfate begins at approximately 680 °C (1256 °F).

2 FeSO 4 → Fe 2 O 3 + SO 2 + SO 3

Like all iron(II) salts, iron(II) sulfate is a reducing agent. For example, it reduces nitric acid to nitrogen monoxide and chlorine to chloride:

6 FeSO 4 + 3 H 2 SO 4 + 2 HNO 3 → 3 Fe 2 (SO 4 ) 3 + 4 H 2 O + 2 NO 6 FeSO 4 + 3 Cl 2 → 2 Fe 2 (SO 4 ) 3 + 2 FeCl 3

Iron(II) sulfate near the titanium dioxide plant in Kaanaa, Pori, Finland.

When exposed to air, it oxidizes to form a corrosive brownish-yellow coating of "basic ferrous sulfate", which is an adduct of iron(III) oxide and iron(III) sulfate:

12 FeSO 4 + 3 O 2 → 4 Fe 2 (SO 4 ) 3 + 2 Fe 2 O 3

This "basic sulfate" can then be decomposed by heat, increasing the yield of sulfur trioxide compared to direct decomposition of ferrous sulfate:

4 Fe 2 (SO 4 ) 3 + 2 Fe 2 O 3 → 12 SO 3 + 6 Fe 2 O 3

However, some of the sulfur trioxide may be lost during thermal decomposition: 2 SO 3 → 2 SO 2 + O 2.

The use of iron sulfate in the furniture industry

Wood etching not only serves as protection, but also gives it a new aesthetic appearance. The resulting color of a wood product depends on the type of wood species. So when etching with ferrous sulfate:

• in a concentration of 0.5% to 2%, oak wood turns dark, almost black;

• in a concentration of 2% to 4%, beech wood becomes brown;
• at a concentration of 4%, birch wood acquires a yellow-brown color;
• in concentrations of 2% to 4%, pine wood acquires a gray-brown color.

Iron sulfate: how to dilute for processing

A solution of ferrous sulfate is prepared in a plastic or glass container using water with a high level of softness. The substance is added gradually, stirring thoroughly until the crystals are completely dissolved.

Photo of the appearance of iron sulfate

How to measure the amount of iron sulfate

When there are no scales at hand, ordinary teaspoons and tablespoons are used to measure the required amount of substance:

• tsp – iron sulfate (5 g) and citric acid (8 g);
• Art. l. – iron sulfate (20 g).

Application of ferrous sulfate in light industry

In this area of ​​the economy, iron sulfate is used - one of the main components of technology in the production of ink, fabric etching, and dyeing of leather goods.

Back in the fifteenth century, a method of dyeing leather for book bindings with a composition based on iron sulfate and gall nuts with soda was developed in France. Thus, they achieved thin leather uniformly colored dark gray. Dyeing with iron sulfate is based on the chemical process of oxidation of natural tannins that make up the leather, resulting in the formation of colored compounds that are insoluble in water. The disadvantages of this ancient method include the fact that thinner areas are damaged by mineral salt in case of uneven dressing of the skin.

The appearance of synthetic dyes in the 19th century and the rapid subsequent development of this area of ​​the chemical industry did not lead to the displacement of ferrous sulfate from leather dyeing technology.

It turned out that such dyes without the use of proven iron sulfate in many cases, especially when processing chrome leather, leads to uneven coloring and visually sharply reveals previously invisible defects. Ferrous sulfate has proven to be indispensable in the production of high-quality leather.

Who is at risk for low iron levels?

Some groups of people have an increased need for iron at certain stages of life. Thus, they are at greater risk of low iron levels and iron deficiency. For other people, lifestyle and diet may lead to low iron levels.

People at greatest risk for low iron levels include (, ):

• babies
• children
• teenage girls
• pregnant women
• premenopausal women
• people with certain chronic diseases
• people who frequently donate blood
• vegetarians and vegans

These groups may benefit most from ferrous sulfate supplements.

Summary:

People at certain stages of life have an increased need for iron and are more susceptible to iron deficiency. Children, teenagers, pregnant women, and people with chronic illnesses are some of the groups that may benefit most from ferrous sulfate.

The use of iron sulfate in the manufacture of paints

Iron sulfate is used in the production of synthetic iron oxide pigments, which determine the color of paints.

By reacting between soda ash and ferrous sulfate in the presence of atmospheric oxygen (sometimes replaced with Berthollet salt), the Mars yellow pigment is obtained. This synthetic pigment is used to make art paints and wood painting materials. Such a pigment prepared in a ratio of 1:8 with filler is called “synthetic ocher”.

Mars red pigment. It is obtained thermally from ferrous sulfate. First, iron sulfate is dehydrated by heating it to 400°C, and then calcined at temperatures ranging from 700°C to 825°C. The shades of the resulting pigment depend on the quality of the manufacturing technology and can range from orange-red to purple and crimson, from pink to lilac shades. The color is determined by the size and shape of the resulting pigment crystals; for light colors the size ranges from 0.35 microns to 0.45 microns, and for dark shades - 2.5 microns. In light flowers, the crystals have needle-shaped particles, while in dark ones they have plate-shaped particles.

The Mars red pigment is in great demand - it is used for the production of various enamels and paints, coloring plastics, paper, and linoleum. Dehydration of iron sulfate and its calcination are carried out in rotary kilns.

The color of the resulting pigment also depends on the temperatures during production. At temperatures from 700°C to 725°C, pigments with a yellowish tint are obtained; at temperatures from 725°C to 825°C, pigments with a bluish tint are obtained.

When producing pigments based on ferrous sulfate, it is possible to obtain different shades by introducing additives, for example, the use of sodium chloride gives a purple tint to the resulting pigment.

Mars brown pigment is produced from iron sulfate by its precipitation in the presence of manganese sulfate with ammonia. The resulting precipitate is separated and then oxidized with air in an alkaline medium, washed, dried, followed by calcination at temperatures from 180°C to 200°C.

Precautionary measures

Iron sulfate has a hazard class of III.

Despite the fact that this is a low hazard class, it is imperative to protect the respiratory tract, skin, and mucous membranes.
To do this, when working with the drug, gloves, a respirator, special clothing, and glasses are used. Children and pets should not be nearby during treatment.

The use of iron sulfate in steel bluing

Steel bluing is a technological process of obtaining an oxide film on the surface of steel, which not only protects the steel, but also gives it a beautiful appearance. The bluing process is carried out in acidic or alkaline solutions, which include iron sulfate.

If you want to get a bluish film, use the following solution:

• iron sulfate – 30 kilograms;
• hydrochloric acid – 30 kilograms;
• mercury nitrate – 30 kilograms;
• ethyl alcohol – 120 kilograms.

The solution is heated to 20°C and the steel product is treated in it for twenty minutes.

If it is necessary to obtain a dark red tint of bluing, use the following solution:

• iron sulfate – 3 kilograms;
• ethyl alcohol – 3 kilograms;
• water – 100 kilograms;
• copper nitrate – 1.2 kilograms.

The solution is heated to 25°C and the surface of the steel product is wetted with a soft brush, allowed to dry and wetted again. The process is repeated several times until the desired shade of red is obtained.

When bluing to obtain dark red shades, rusty spots sometimes form - they are removed carefully with a damp brush and the solution is applied again.

To fix the resulting protective film on the surface, it is then treated with one of two methods.

1. Method 1. Rinse for a long time in running water, and then boil for five minutes in a solution of three kilograms of soap per one hundred liters of water.
2. Method 2. Rinse for a long time in hot water, and then immerse for 2 minutes in a solution of sodium bichromate heated to 70°C (12 kilograms per hundred liters of water).

At the final stage of bluing, the steel product is dried and then thoroughly lubricated with some type of machine oil.

Application of ferrous sulfate in electroforming

In this area of ​​industrial production, iron sulfate is used in the manufacture of molds and dies. The accuracy of the mold dimensions and the absence of roughness during electroplating, during which the resulting metal copies are separated from the model that serves as the basis for metal deposition, plays a very important role after completion of the process. In this case, it is important that the surface of the model and the layers applied for leveling have conductive properties. To fulfill these technological requirements, sulfuric acid electrolytes, which include ferrous sulfate, are used. The galvanoplasty process is carried out under constant supervision.

Electroplating using iron sulfate is a fairly lengthy process. The deposition time of thick layers of metal can take several weeks. But the waiting time pays off in the high quality of the resulting surfaces and compliance with dimensional accuracy.

Before applying electrolytes, the surfaces of the models are thoroughly washed and degreased, and then completely dried.

Preparation of iron sulfate solution

To prepare a solution that is close in composition to iron chelate, ferrous sulfate is combined with citric acid or ascorbic acid.

A solution of iron sulfate with citric acid

Take 8 grams of acid and dissolve it in 1 liter of water.

Stir with a wooden or plastic spatula.
Add 5 grams of iron sulfate. Stir again. Add 2 liters of water. When all the crystals are completely dissolved, the solution acquires an orange tint (the concentration of the main substance is 0.5%). Use only freshly prepared solution.

How to prepare a solution of iron sulfate with ascorbic acid

To prepare this solution, take 10 grams of ascorbic acid and 5 grams of iron sulfate per 3 liters of water.

The preparation method is the same as with citric acid.

Photo instructions for use from the manufacturer

Important!

Ascorbic acid should not contain glucose or other additives.

Iron oxidation occurs in the shortest possible time, and therefore it must be used immediately.

When using only ferrous sulfate, the indicated dosages must be followed.

Iron sulfate for treating plants - video

Application of ferrous sulfate for making ink

Using iron sulfate to prepare ink is perhaps the oldest method of obtaining solutions for applying images to paper. It is based on the processes of acquiring a black color when mixing solutions of tannins and copper sulfate.

Iron sulfate is an integral component of ancient compositions for secret writing and images. The inscriptions were applied to the paper, the canvas with a 1% solution of tannin 0.1 M, and then at the right moment they were wiped with a 0.1 M solution of ferrous sulfate, and the inscription became visible.

Safety requirements

Shelf life: 1 year from the date of manufacture

Safety precautions when working with ferrous sulfate

Ferrous sulfate is not subject to special fire protection requirements. This substance is non-flammable and non-explosive. However, in relation to health, it poses some danger if handled carelessly.

This chemical belongs to the third toxicity class, which includes materials moderately hazardous to human health.

When using sulfate, it is not allowed to contain iron sulfate aerosols in the air of working areas in concentrations higher than the maximum permissible, which is 2 mg/m².

Crystal lattice: