One of the main tasks of the state is to ensure the safety of citizens, including in the winter. This requires deicing reagents - solid (free-flowing), liquid or combined chemicals that can melt snow, ice and snow-ice formations, as well as reduce the freezing point of brine, which consists of melt water and a reagent. Most often, the following types of salts are used as reagents: chlorides, acetates, urea, formates, nitrates.

These substances have different operating temperatures, melting ability (the ability of 1 gram of a substance to melt a certain amount of ice), corrosiveness to metal and concrete, price, impact on footwear, animals, soil, and human health.

Here is a summary table in which we will analyze the main properties and characteristics of products designed to combat ice.

We will compare according to the following indicators: operating temperature, melting capacity, corrosivity, cost, impact on the environment, urban infrastructure and human health.

Reagent name	Working temperature	Melting ability	Corrosive activity	Price	Impact on humans and the environment	Output
Sand-salt mixture	before 12 ° C (judging by sodium chloride (the only melting substance in the composition))	almost zero melting capacity, since the proportion of salt in the mixture is negligible (about 5%) - it is mainly added to prevent sand caking	high in relation to metal structures and cement concrete	about 1 200 rubles per ton	according to WHO, it causes oncological, allergic and cardiovascular diseases. Leads to exacerbation of diseases of the respiratory system	Ineffective in the fight against ice. Does not increase traction, causes “secondary” icing. It leads to dustiness in the air, which has a negative effect on the human body. Leads to clogging of storm drains, which is very expensive to clean. High distribution and cleaning costs.
Sodium chloride (technical salt, halite)	before 12 ° C	at temperatures below -10 ° C - very low melting capacity	0.8 mg / cm 2 Day - rather high	about 3500 rubles per ton, at a low price it has a high consumption rate - 150-200 g / m2	sodium chloride promotes soil salinization, aggressive towards footwear and fur	Sodium chloride has a relatively low price, but at the same time a high consumption rate, negatively affects the soil, and has a high corrosive activity. Only works effectively down to -12 ° C. Application in populated areas is prohibited.
Calcium chloride	34 o C	lower melting capacity than sodium chloride	has one of the highest levels of corrosivity - 1.02 mg / cm 2 days	price - from 15,000 rubles per ton, but at the same time low consumption - 50-70 g / m2	negative effect on shoes, irritating the skin	The biggest plus of this substance is its low operating temperature. For the rest, there are practically only drawbacks - high corrosive activity, an impressive price, a negative impact on people's health and on their property.
Magnesium chloride (bischofite)	18 about C (solution)	have a 2.0-2.5 times lower melting capacity than anti-icing materials based on other salts. This is due to the fact that the active substance in solid bischofite is not more than 48%. The rest is crystalline moisture	solid bischofite can have a value of 1.1 mg / cm 2 * days (when exposed to steel grade 3) with a permissible value of 0.8.	the cost of bischofite is about 20,000 rubles per ton	Bischofite contains compounds of potentially toxic elements (first and second hazard classes): heavy metals - selenium, fluorine, bromine. That is, in high concentrations, this substance is dangerous to plants and animals, as well as to humans. Bischofite has a detrimental effect on plants, in agriculture it is used as a desiccant	In 2004, the use of magnesium chloride as a deicing material was banned in Moscow. The anti-icing agent Bischofite threatens human health and harms the environment. environment.
Potassium chloride	4 ° C	melting capacity is low		about 18,000 rubles per ton	beneficial effect on soil, fertilizer, low toxicity	Due to its low melting ability, this salt is used mainly as a component in other anti-icing agents, as well as in specialized areas - kindergartens and so on.
Nitrates	30 o C	high melting capacity		from 60,000 rubles per ton	nitrates are destructive to nature, have a bad effect on soil. In Moscow, the use of nitrates was banned in 2010 after an experimental winter	the use of nitrates in settlements is extremely limited: bridges, overpasses
Acetates	down to -50 ° C	high melting capacity	low corrosive effect	90,000 rubles per ton	use in settlements is prohibited due to the smell of vinegar. In some cases, it causes suffocation, nausea and dizziness in people.	Acetate-based deicing agents are used only in well-ventilated areas (bridges, flyovers, or airfields). They cannot be used in cities.
Formates	down to -19 ° C	high melting capacity at -5 ° C and -10 ° C	0.14 mg / cm 2 * day - sodium formate has a corrosiveness of 8-10 times lower than sodium chloride and calcium chloride	from 30,000 rubles per ton	do not have a harmful effect on shoes and fur, decompose in soils. Formates - organic salts that do not harm human and animal health, is a part of some medicines, used as a feed for animals (in particular, rabbits) so that food is better absorbed	Hazard class for formates 4th - low-hazard substances. Considering that sodium formate is able to significantly reduce the negative properties of chlorides, at the moment this substance is widely used as a component in salt mixtures, which makes it possible to achieve a ratio of "efficiency and economic feasibility." In its pure form, sodium formate is used at airfields, as well as in park and forest areas and in specially protected areas. The use of sodium formate in its pure form in cities is impossible due to its high price, but multicomponent anti-icing reagents with this substance in the composition are recommended for use.
Urea	up to -4 o C	low melting capacity	does not adversely affect metals	from 8000 rubles per ton	does not affect footwear and fur, is positive to plants and soils (it is a fertilizer), low toxicity. But at the same time, its use is not recommended near water bodies.	used as a component for multicomponent deicing agents.
Multicomponent reagents with formates ("Bionord" type)	up to -25 o C	high melting capacity	low corrosiveness	from 15,000 rubles per ton	do not cause allergies, decompose in soil, safe for humans and animals.	Due to the average price and low consumption rate of 50-70 g / m2, the use of multicomponent reagents is beneficial. The addition of sodium formate to the composition of the products minimizes the negative impact on metal and concrete. They do not pollute the soil, are removed from it within 72 hours, decaying into carbon dioxide and water. Multicomponent anti-ice reagents such as "Bionord" combine the high melting capacity of chlorides and the environmental friendliness of formates.

We conclude that almost all ice-melting substances, if they are used as one-component anti-ice reagents, have their drawbacks. Therefore, from the point of view of a combination of efficiency, environmental friendliness and a favorable price, multicomponent deicing agents with sodium formate in the composition are most suitable for use in an urban environment.

An example is the Bionord product, which is produced by the Ural Plant of Deicing Materials (UZPM). It is a reagent based on several chloride salts and formates. In Moscow, anti-icing reagents of the Bionord type have been used for more than 4 years, during this time the number of injuries among pedestrians has decreased by 2.5 times, the number of accidents due to unsatisfactory road conditions has decreased by 30%, despite the growth of the vehicle fleet ... Also, the percentage of soil salinity has decreased by 2 times. Compositions of this type are considered the safest chloride-based deicing materials in Russia.

The most common means of dealing with ice during the winter cold are anti-ice reagents, which differ from each other not only in chemical composition or type of origin, but also in the form of release. Recently, the greatest demand is for granular reagents, which have increased efficiency..

In order for the fight against ice to be as effective as possible in all weather conditions, it is necessary to choose the right anti-ice reagents for road treatment. Currently, the most popular and widespread anti-ice agents are calcium chloride, industrial salt, marble and granite chips, and magnesium chloride.

According to their structure and form of release, all reagents used are divided into several types:

• Powder. This is the most famous and widespread form of release of anti-icing agents, which is a free-flowing substance. Most often, reagents such as sodium chloride and calcium chloride are produced in powder form. The main advantage of this form of release of the substance is its ease of storage.
• Liquid. This is a relatively new form of production of anti-icing agents, which is most often used to remove snow from areas in small businesses and in private yards. The disadvantage of liquid reagents is their relatively high cost compared to substances in other forms of release.
• Granular. This form of release of reagents is solid small granules, which, in addition to anti-icing qualities, also have abrasive properties, preventing slipping on an icy road. Recently, it is granular reagents that are in high demand, since their cost is comparable to powder agents, and their efficiency and speed are several times higher.

The main advantage of granular deicing agents is their optimal shape, which is small round grains. Due to this structure, the granules, barely falling on the ice surface, instantly come into contact with the ice, biting into it during use. The result of such an impact is not only the rapid melting of ice, but also its splitting, which reduces the adhesion of the ice crust to the road surface. Thus, after using reagents in granules, ice remains are easily removed from the asphalt using improvised means or special equipment.

Additional properties of granular reagents

In addition to all the above advantages of a deicing agent in granules, granular calcium chloride or magnesium chloride also has such advantages as:

• Environmental friendliness and safety of operation. Unlike industrial salt, which in the process of use causes irreparable damage to road surfaces and other surfaces, granular reagents do not cause any harm to the environment.
• Resistant to frost. Due to the special structure, the granules of the anti-icing agent are able to efficiently perform their work even at low air temperatures down to -30C °.

Due to its affordable cost, safety and high efficiency, calcium chloride in granules is actively replacing technical salt and sand-salt mixture in many settlements.

Cleaning of snow and ice has always been considered one of the main problems of public utilities, and despite the constant introduction of new methods of saving from ice, salt is still in use. The Village collected 5 technologies for cleaning streets in those countries where it snows in winter, learned about their pros and cons, and took comments from ecologists, shoe makers and ordinary people.

SALT (NaCl)

PETERSBURG, MOSCOW, KIEV

Cheapness

Harm. Salt is a chloride, a very active substance. For example, a few years ago, it led to an accident at the Southern substation (Petersburg), severing the wires laid underground. Salt corrodes pipes, bridges, cars, causes allergies, damages shoes, clothes, paws of animals and historical monuments. Not to mention the environment, as it gets into groundwater, soil and rivers.

Sidewalks are sprinkled with technical salt or salt mixtures based on it
Snow removal in Kiev

MOSCOW

In cleaning up territories, the capital has advanced further than other regions. Moscow road workers are proud of their system of preventive measures: even before snow falls, roads are treated with liquid reagents - 28% solution of calcium chloride and sodium chloride (food salt). The processing is done on the basis of data from the meteorological service and a radar system capable of predicting the amount of precipitation with an accuracy of 1 mm of water or 1 cm of snow. Moscow utilities love reagents - this year for the first time they decided to sprinkle them on yards and sharply increased the volume of purchases of solid chemicals.

270,000 tons of salt cover an area of ​​88 million square meters. m. In winter, cleaning Moscow roads takes 2.1 billion rubles a month.

KIEV

PETERSBURG

Also on the streets you can find sand and traces of the action of a special mixture "Bionord", which is used to clean the sidewalks. It includes three types of salt: calcium chloride, magnesium chloride and sodium chloride. For the winter, the city purchased 92,000 tons of Bionord. There is even a special name for the snow porridge, which is obtained as a result of the action of salt, - sludge. Salt is capable of melting ice up to a temperature of minus 21 ° С, however, when the thermometer drops below minus 9–10 ° С, its effectiveness drops sharply. In Finland, salt is no longer used as soon as the temperature drops below minus 5 ° C. Finnish meteorologists say roads become less slippery at very low temperatures.

Opinion: Chemicals on the roads

Evgeniy, shoe repair master "Vip-master":“Salt corrodes threads the most. Therefore, sewn shoes suffer the most. In addition, in recent years, the quality of footwear has fallen: the manufacturing technology has changed, factory rejects have become more frequent, materials have become worse. Therefore, shoes suffer from salt very much. If we talk about high quality leather shoes, then salt does not cause much harm with daily care and drying. In years with a small amount of snow, on the contrary, the shoes are washed more, the repair of heels and rolls increases significantly ”.

FRICTIONAL METHOD:
SAND AND STONE CRUSH

AUSTRIA, FINLAND, GERMANY, SWEDEN AND OTHERS

environmental friendliness, reusability

lingers on the carriageway for no more than half an hour:
it is blown away by the wind, by the wheels of cars and by the feet of pedestrians.

In Helsinki, snow is compacted and sprinkled with stone chips

After much trial, error and scientific research, Europe has almost completely abandoned the use of chemicals to melt snow and ice. In Berlin, for example, the law permits the use of salt only on hazardous road sections. Chemicals are all too obvious harm to the environment and urban economy. Fine sand is also not the best option. It produces dust, gets into the lungs and is not recyclable. Whereas gravel and stone chips are environmentally friendly and economical, although initially they are more expensive than salt.

In the spring, the crumbs are collected again with special devices resembling a vacuum cleaner, washed and reused the next year.

The method of spreading sand and other abrasive (hard and fine-grained) materials is called frictional: ice cannot be completely eliminated by this method, but traction is improved. The main condition for using this technology is that the roads must be cleaned almost to asphalt immediately after or during a snowfall. In some European cities, there are even special gravel boxes set up for pedestrians so that residents can scatter the sand themselves if it is very slippery. By the way, such boxes can sometimes be found in St. Petersburg, for example, on Bolshoy Sampsonievsky Prospekt and near the Staraya Derevnya metro station.

In 2010, 22 million euros were allocated for road maintenance in winter in Finland, but due to heavy snowfalls, the budget was exceeded by 17 million.

Aurora Ramo, resident of Helsinki:“When it snows at night, it is usually cleared before people wake up and go to work. But if there is a lot of snow, then they do not have time to remove it, and then everything stops! Three days ago, I waited 45 minutes for a bus: they just don't go anywhere, although they usually go every 10 minutes. Sometimes passengers even have to push the bus out of the snow. As for ice - I don't know how often the sidewalk is sprinkled with crumbs, but I have never slipped this winter, even very drunk. And the shoes are all right. This applies to the streets, and in the courtyards no one is responsible for throwing gravel, my grandmother recently fell on the ice because of this. But in Berlin in winter it is very slippery. Last year I felt as if I had come to the rink without skates. "

TORGEIR WAA METHOD

SWEDEN

efficiency, environmental friendliness, long-term result

special expensive equipment is needed

The method invented by Thorgeir Vaa is being piloted in Sweden

In 2004, Sweden introduced a new method of dealing with ice, which was invented by the Swedish scientist Thorgeir Vaa. Fine sand in a ratio of 7 to 3 is mixed with hot water at 90–95 ° C and sprayed on the streets. Hot sand melts into the snow and makes the surface rough. Such processing is enough for 3-7 days with daily traffic of about 1,500 vehicles. Or until another snowfall has passed.

ALTERNATIVE CHEMICALS

USA, CANADA, NEW ZEALAND

Magnesium chloride

high efficiency

more expensive than technical salt and causes
even more severe corrosion of metals

Great Salt Lakes in Utah

Americans and Canadians use mainly magnesium chloride, which is mined from the Great Salt Lakes in Utah, to clean streets and sidewalks. MgCl2 contains less chlorine than other chlorides, and its efficiency is much higher at lower consumption. In the winter of 2010, Maryland spent $ 50 million on road cleaning, and Virginia $ 79 million. Canada spends $ 1 billion annually on road maintenance in winter.

Calcium magnesium acetate and calcium chloride environmental friendliness high cost, cannot be used at low temperatures Snowfall in Wellington Calcium magnesium acetate is used in most cities in New Zealand. For metals, it is no more harmful than water, and it has a small effect on the environment due to the absence of a chlorine ion. However, this chemical is used only down to minus 7 ° C. Calcium chloride is also a popular remedy. By the way, its 10% solution is sold in pharmacies, and at home, CaCl2 is used to make cottage cheese.

Urea good for the environment 7 times more expensive than salt, ineffective Suspension bridge cleared of snow with urea Of organic products, urea is most often used. Due to its low corrosiveness, it is usually used to remove ice from suspension bridges. Urea is non-toxic, but not effective enough for use in large cities.

NO FUNDS

JAPAN AND THE REST 230 COUNTRIES

After a snowfall in Aomori Prefecture

In the mountains of Japan, up to several meters of snow falls during the winter, and in cities - 15–20 cm per night. As a result, by the end of winter, sidewalks and intercity roads turn into narrow snowy canyons with walls 2 human height or more. However, the roads in Japan are not processed in any way, only the snow is removed. Therefore, ice in cities is not such a rare occurrence. At the same time, studded tires are prohibited in the country. By the way, snow removal near houses and on sidewalks is the responsibility of the residents themselves.

ECOLOGIST'S OPINION

Semyon Gordyshevsky, Chairman of the Board of NP "St. Petersburg Ecological Union":“The best way is just to clear the snow on time and clean. Finns and Swedes do it easily. Finland has adopted the most environmentally friendly regulation that states the minimum use of salt. In St. Petersburg, they are waiting for the snow to be trampled down to ice, and then covered with salt. Few people think about where the salt goes from the streets. And it either from sidewalks and snow-melting plants gets into the sewage and then is filtered out at treatment facilities, or flows down with water into canals and is carried out into the bay. And, oddly enough, the first option is worse. The sludge from the wastewater treatment plant is incinerated. And the chlorine contained in salt, when burned, releases very dangerous substances - dioxides, polycyclic aromatic hydrocarbons and other compounds. In St. Petersburg, such a sludge is burned by 3 factories. And all the burnt out household chemicals, detergents and salt in the form of dangerous compounds are carried away from them by the wind through the city. "

Anti-icing reagents are modern means that ensure the passability of roads in large cities. They can help make the roads safer, and the tools themselves are harmless to the environment.

How do reagents work?

Most of these products are designed to lower the melting point of the snow. When sprinkling snow, anti-icing reagents lead to the fact that the active substance generates heat, which quickly clears the roads from icing and drifts. All mixtures are solid or liquid, in our country the first option is most often used, since it differs:

1. Ease of use.
2. No need to use special equipment and special training of personnel.
3. Low cost over a large footprint.

Most often they are granular and have better melting properties. In addition, some deicing agents of this type can be used even at temperatures below 30 degrees. Some formulations are supplemented with corrosion inhibitors that protect the road surface from deterioration. The snow melts and is easily removed, and the degree of slip is reduced, due to which the road is clean and safe.

From the history

The need to use reagents arises every winter, as this is the easiest way to timely avoid the formation of ice on the roads. The production of anti-ice reagents is carried out in accordance with GOSTs so that the final composition does not have a harmful effect on the natural balance, is easily removed from the soil and does not lead to damage to car tires. Due to the fact that modern technologies are improving, and the quantity and quality of the raw materials used is growing, modern anti-icing agents are able to ensure environmental friendliness and safety of use.

It is noteworthy, but in recent years, these compositions have changed significantly, and the usual sand-salt mixture (92% - sand, 8% - technical salt) has been replaced by more modern anti-icing reagents. Their composition is different, which depends on the purpose of the product and the scope of its application. Over time, use became impractical, since in the spring there was sand on the roads, which clogged the gutters. Later it was customary to use as a reagent just technical salt, which quickly melted ice, was distinguished by resistance to frost and constant action.

On the other hand, such anti-icing reagents - first of all technical salt - had drawbacks. First of all, they were expressed in corroding car bodies, shoes of passers-by, and where the soil turned out to be too salty, nothing grew.

Primary requirements

The principle of operation of most anti-icing products is simple: it absorbs moisture from the ice, as the crystals become saturated with water, they turn into a liquid, heat up and melt the frozen crystals. Today, a different anti-icing agent can be used to process the roadway - GOST is different for each material, as well as technical requirements:

1. Maximum safety for the environment.
2. No harm to the natural balance of the soil.
3. High efficiency: that is, products at low concentrations must be fast working at all temperatures.
4. Ease of use: most formulations are scattered or sprayed on the soil.

Composition

Anti-icing reagents mostly consist of various salts - chlorides, chlorates, hydrochlorides, which begin to act at extreme temperatures, and act instantly. The effectiveness of reagents is increased due to several components:

• anti-corrosion additives;
• biophilic components that improve soil quality;
• accelerating additives that act in extreme temperatures;
• baking powder.

Calcium chloride

In recent years, more advanced deicing agents have been used, the technical characteristics of which contribute to the observance of environmental standards. And the usual solid formulations have been replaced by effective liquid formulations that are easy to apply and do not leave marks on the road, on wheels, or on shoes. Most often, of the liquid analogs, HKM is used, which is less consumed, is capable of melting ice even at low temperatures and prevents the appearance of ice.

On the other hand, the deicing reagent based on had disadvantages:

1. It is valid for only three hours, so the road must be processed constantly.
2. Scientists who studied the composition of this tool came to the conclusion that when it is used, the coefficient of adhesion of tires to the road surface decreases, that is, it turns out that XKM attracts moisture, while technical salt repels it.
3. Calcium chloride did not meet the requirements of environmental friendliness, as it could cause allergies and corrode the metal of vehicles.

Advantages and disadvantages

Experts note that due to its hygroscopic properties, calcium chloride reacts with it when it hits the snow and releases heat. Such deicing agents, the technical characteristics of which are very different, do not harm the environment. The benefits of using this anti-icing agent include:

• the ability to quickly and deeply penetrate the ice layer;
• prompt melting of ice and fertilization of the soil;
• reduction of adhesion forces between ice and road surface due to the formation of brine;
• reagent activity, which affects its lower consumption.

"Icemelt"

The use of anti-ice reagents is aimed at timely clearing the streets of cities from snow. "Icemelt" is a modified substance capable of acting at the lowest possible temperature of -20 degrees. The use of this substance is advisable due to its effectiveness, efficiency, safety and the possibility of using it even on grass. The structure of the anti-ice agent is a gray crystalline granules, consisting of sodium chloride, a corrosion inhibitor, which is needed to protect the surface.

Application of "Aysmelt"

The composition of the material allows it to be used in two directions:

1. As a preventive measure. In this case, "Eismelt" is used in advance, even before the onset of winter, to treat the coating, which is most exposed to the risk of icing. It is best if the treatment is carried out before precipitation. The substance should be evenly distributed over the surface.
2. For the fight against ice. In this case, the material is applied to the ice surface, dissolving the particles. Before processing, the coating must be free of loose snow.

These anti-icing reagents have several features:

• easy to use;
• consumed in small quantities;
• do not contain harmful substances and impurities, therefore, if used correctly, they will be safe for nature, people and animals.

Granite chips

This anti-icing drug has been used as such for a long time, since there are no harmful substances in it, and its cost pleases with its availability. For processing the road against ice, crumb of fraction 2-5 mm is suitable, which is easy to distribute over the surface. Granite chips are different:

• durability;
• durability;
• environmental friendliness and safety;
• use at any temperature.

Granite chips are produced by crushing crushed granite rocks, after which the material is sieved and washed - this is necessary in order to rid the composition of granite dust. Of course, this is not a reagent in the literal sense of the word, since the crumb does not melt ice, but due to its high abrasiveness and good adhesion to the ice surface, the material has found wide application in this capacity.

Sand salt

Perhaps the sand-salt mixture is the most popular way to get rid of ice. It is a combination of river sand with technical salt. The use of this composition is advisable due to its low cost and the possibility of using it in any temperature conditions. The mixture is created taking into account certain proportions, which depends on the degree of ice and the characteristics of the surface to be treated. The effectiveness of using this reagent is explained by several features:

• sand, due to its abrasiveness, contributes to better adhesion of the wheels of vehicles and the surface of the roadway;
• technical salt melts the ice, making it less slippery.

Among the advantages of using this composition are affordable cost, ease of use, quick action on the roadway and use in any conditions. But it is worth remembering that if low grade sand is used, in which there are many small particles, this will lead to the formation of mess on the road. A good mixture consists of refined fractional sand. The second point is that the use of the composition is advisable only if there is a temperature of at least 20 degrees, since at lower temperatures the mixture will stick together, and it will not be easy to evenly distribute it.

Liquid products

Today, liquid deicing agents are becoming more and more popular. They are most often based on calcium chloride, and their main purpose is to fight ice on a winter road, which has a lot of traffic. The advantages of using liquid formulations include:

• the effectiveness of the impact on ice;
• facilitating mechanical snow removal;
• ensuring the level of safety on the road;
• fast distribution over the surface;
• ease of transportation.

Technology features

For the first time the technology of liquid reagents was used in Europe, and today it is popular in Russia as well. The essence of the process is that dry salt is moistened with solutions based on calcium chloride, which increases its effectiveness. The wetting technology is good because:

1. The reagent is evenly distributed over the road surface.
2. The adhesion of the compound to the roadway becomes better.
3. The reagent remains on the road and is not carried away by cars, unlike solid materials, therefore, it is advisable to use liquid solutions on the road with high intensity.
4. The use of a liquid reagent reduces the salt load on the environment.

Selection rules

Before choosing a deicing material, you need to take into account its characteristics such as:

1. High melting capacity. For example, calcium chloride is more effective than industrial salt in terms of its impact on the ice cover.
2. Sufficient crystallization temperature, which allows the reagent to be used for a long time.
3. Acceptable viscosity of the composition, which guarantees the safety of its use on the roadway. If the material contains calcium chloride, then it can be used even at extreme temperatures.

Remember that liquid reagents are more effective as they wet the surface. In addition, the use of such compositions is advisable due to the uniformity of distribution over the road surface, low consumption and a wide temperature range of operation.