Process for processing rock salt. Edible salt: the main methods of extraction and production Obtaining industrial salt
Salt production is a very good business idea. Salt is always a tradable and rather liquid commodity, which practically does not deteriorate, has a constant demand and an infinite shelf life. All these qualities indicate that salt is an ideal commodity, and salt processing and its subsequent sale is a good and cost-effective idea to start your business.
But the production process directly depends on the type of salt itself.
One of the healthiest is sea salt. It contains various very useful minerals. Sea salt is obtained by evaporating sea water, because it contains a huge list of salts with various additives.
If doing salt production, then in this case it is necessary to carefully consider business plan
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In order to obtain table salt, halite, or rock salt, is needed. Basically, first they develop halite deposits, and then, after a whole specific processing process, table salt is obtained from the mined rock salt. But besides this method, the evaporation of salt from salt water is also practiced. It can be both sea water and water of saline reservoirs - lakes or ponds. However, this alternative method becomes profitable only in cases of a large number of the above reservoirs.
Halite is the mineral from which table salt is made. It, like any mineral, contains foreign inclusions in the form of sand, earth or some metal parts. For this reason, as soon as raw salt enters the plant, it first goes through several stages of purification. First, it is washed twice with various types of devices, then it goes through the crushing stage, and at the end it is washed twice again. At the same time, the magnetic separator screens out metal impurities that may be in the halite. After the salt has passed the stage of purification from impurities, it is dried using a special centrifuge.
In order to obtain large iodized salt, the resulting semi-finished product is sent to the unit for adding iodine, and then to vibration drying. If coarse salt should not be iodized, then the step of adding iodine is skipped, and the salt directly enters the vibration dryer. In the event that fine table salt is needed, then after the semi-finished product has passed the stage of adding iodine and vibration drying, it is sent to the crusher. If the fine salt is not to be iodized, then this processing step is excluded from the production process.
After the process of adding iodine and crushing, the salt is dried. This happens with the help of hot air, which is blown into the furnace by an industrial fan. Also, at this stage, you can add other excipients. These may be some food additives that resist caking of table salt, iodides, carbonates, fluorides. Fluoride supplementation is useful for preventing dental disease. At the same time, the total amount of food additives in salt should not exceed 2-3% (as a percentage).
After all auxiliary substances are added to the salt, it is completely ready for packaging.
Video - how sea salt is mined and produced:
Salt is mined in more than 100 countries around the world. The natural reserves of this soluble mineral are truly enormous - salt is found in salt lakes, natural salt brines and in the bowels of the Earth, while the depth of stone layers sometimes exceeds 5 km. Speaking in numbers, the salt reserve of the waters of the World Ocean is approximately 5 x 1016 tons. Rock salt reserves are also impressive - 3.5 x 1015 tons. Scientists have calculated that the amount of salt contained in the water of the seas and salt lakes would be enough to cover our planet with a layer of 45 meters thick.
The formation of salt deposits took place over millions of years, and the history of salt mining has been around for about 7 millennia. The first information that people are engaged in salt mining dates back to the 5th century BC. BC. During archaeological excavations in Austria, salt mines were discovered, where the mineral was already mined in the Bronze Age. For a long time, the extraction of salt was hard work and until the beginning of the 20th century was carried out manually: shovels, picks and wheelbarrows were the only tools of production.
It was possible to mechanize the process of salt extraction only by the 20s of the last century, when the first cutters for the construction of mines, salt harvesters and excavators appeared. Currently, salt is obtained and produced using modern machines and equipment, which allows minimizing the use of manual labor. More than 180 million tons of salt are produced in the world per year, while about half of the total production falls on salt industry enterprises in the CIS, the USA and China. Large salt reserves have been found in Mexico, France, India, Iraq, Turkmenistan, etc.
The history of salt mining in Russia goes back to the 11th century. AD - it was then, according to historians, that the salt industry was organized in Russia, which brought good income to the owners of the salt works. By the beginning of the 18th century Salt production in our country became widespread, by the beginning of the 19th century. almost 350 thousand tons of salt were mined from the explored deposits per year, and by the beginning of the 20th century. this figure rose to 1.8 million tons per year.
In the vast expanses of our country, hundreds of salt deposits have been explored, which contain more than 100 billion tons of salt. The most famous of them are Baskunchakskoe (Astrakhan region), Eltonskoe (Volgograd region), Iletskoe deposits. In addition, Russia is in second place in the world after Canada in the extraction of potash salts, which are mainly used for the production of potash fertilizers, which are widely used in agriculture.
Salt extraction methods
To date, several types of salt extraction are used, which we consider in more detail below.
The basin method is used for the extraction of self-planting salt, which is formed in the water of the seas and lakes. In fact, this method was suggested to people by nature itself. Its essence is simple: in estuaries, which are separated from the sea by sandy spits or dunes, salt is deposited in dry and hot weather, which can be collected and sent for processing. A simple process of salt deposition made it possible to artificially reproduce it, for which purpose pools were built in ecologically clean coastal zones that communicated with the sea and with each other. As a result of exposure to the sun and wind, the salt naturally evaporated and remained at the bottom of the pool. The technology of extracting sea salt has not changed for centuries and allows you to preserve the natural composition of the product.
Solid salt, located in the bowels of our planet, forms real mountains, the base of which goes 5-8 km deep, and the peaks often protrude above the earth's surface in the form of salt domes. Their formation occurs as a result of the impact on the rock salt mass of interlayer pressure and temperature. Becoming plastic, the salt monolith slowly moves up to the surface of the earth, where rock salt is mined. If its deposits are located at a depth of 100 to 600 meters, then mining is carried out by the mine method.
The mine itself resembles a long tunnel, the walls of which are made of natural salt. It is located in the thickness of the salt bed or dome. A lot of galleries or chambers depart from the main corridor, which are built using special cutting machines or heading machines. Scrapers are used to extract and load the produced salt, and to facilitate transportation, the resulting pieces of salt are cut into smaller pieces and sent to the processing plant on special elevators or trolleys along the mine railway. There, salt is ground and packed into packages, after which the finished product goes to stores. The degree of grinding, packaging and additives can be different, the end consumer chooses the best option for himself. Salt enriched with iodine is in high demand - it is recommended for use as a prophylactic agent for iodine deficiency diseases.
The process of extracting salt by the mine method does not depend on the season and is carried out continuously. It is estimated that more than 60% of all salt in the world is mined in this way. The efficiency of exploitation of depleted salt deposits is increased due to the fact that depleted chambers are often used to dispose of waste from industrial enterprises. Among the shortcomings, it is worth noting the high probability of the collapse of the salt mine and its possible flooding, which leads to serious environmental and economic losses.
Another way to extract rock salt is called in-situ leaching. Depending on the thickness and depth of the salt layer, a network of wells is laid in the field, into which fresh hot water is pumped, dissolving the salt rock. The liquified brine is pumped out using slurry pumps. The need to use just such equipment, which would be resistant to chemical and mechanical stress, is determined by the aggressive environment of the solution (the salt concentration in it is very high) and the content of sharp and solid particles in it.
Entering the huge vacuum tanks with reduced pressure, the salt solution begins to evaporate, and the salt crystals settle to the bottom. Grind the resulting salt using a centrifuge. This method of extracting table salt, which is also called vacuum, has a number of advantages, including the low cost of brine, the possibility of extracting the product in deep deposits (from 2 km), a minimum of human resources, etc.
The process of salt extraction is often not complete without salt-mining combines. This technique, resembling a double-decker wagon, moves along a railway laid in the place of salt extraction, and with the help of a cutter loosens the dense salt structure. The mineral mixed with lake water is pumped out by special pumps and enters the processing chamber. The devices located in it separate the salt from the liquid and wash it, after which the finished raw materials are loaded into wagons, which drive up to the combine along special rails. The productivity of the salt-mining combine reaches 300 tons of salt per hour. Combined salt mining allows you to almost completely abandon drilling and blasting. The thickness of the salt layers that the harvester can process ranges from 1 to 8 meters
Similar salt-mining combines are used on Lake Baskunchak. Salt has been mined at this largest deposit, located in the Astrakhan region, since the 17th century, and it produces more than 930 tons of salt per year. Baskunchak is a unique deposit, because it is one of the few that is able to restore lost reserves from the sources that feed the lake. The discovered salt layers on the site of the lake go as deep as 10 km.
If we talk about small salt-mining enterprises, then they mine lake salt using excavators. However, unlike salt-mining combines, which produce destruction, selection, enrichment, dehydration and shipment of the mined mineral to railway cars or dump cars, the operation of excavators has a number of limitations. These include a significant level of brine in the lake and karstification of salt layers. The feasibility of extracting salt by excavation is permissible with a production volume not exceeding 80 thousand tons per year.
Salt processing is carried out in two stages. The first stage is carried out underground in a salt processing chamber, where the original salt is screened along a separation boundary of 4.5 mm, crushed, crushed and classified in sequential order oversize product with a fraction of more than 4.5 mm, with the final separation of three products: fractions from 2 .5 to 4.5 mm, an intermediate product with a fraction from 0.2 to 2.5 mm and a fraction from 0 to 0.2 mm. The latter is used in the mine for storage and disposal, and the remaining two products are simultaneously brought to the surface by two parallel transport lines, including one two-vessel lifting unit. At the second stage of processing in one of the factory buildings, the product with a fraction of 2.5 to 4.5 mm is packaged, and the intermediate dedusted product is classified into fractions from 1.2 mm to 2.5 mm, from 0.8 mm to 1.2 mm , from 0.2 mm to 0.8 mm and then packed. The task of reducing costs and negative impact on the environment is being solved. 3 w.p. f-ly, 1 ill.
The invention relates to the field of industrial processing of rock salt and bringing its granulometric composition to consumer standards. A known method of processing rock salt, in which the salt mined by the underground method with a fraction of 0 mm to 280 mm is given to the surface, crushed, crushed, classified and packaged (see Furman A.A. et al. Table salt. Production and use in the chemical industry, Moscow, "Chemistry", 1989, pp. 117-124). The disadvantages of this method are: 1. Negative impact on the environment, because. the entire process of processing rock salt, including the operation of removing a fine pulverized fraction from 0 mm to 0.2 mm from the classification product, must be carried out directly on the daylight surface. 2. A complex of problems caused by the presence of a fraction from 0 mm to 0.2 mm (hereinafter referred to as dust) in the total volume of the fraction issued from the mine and processed on the salt surface. Dust is considered a waste product and must be disposed of. The only known method of its disposal is the production of salt briquettes from it, and therefore, as part of a salt processing plant, it is necessary to provide an energy-intensive and capital-intensive briquetting site (workshop). In addition, due to the low flowability of dust, which makes it difficult to transport for disposal, it is required to add coarser-grained salt (fraction up to 4.5 mm) to it using a special technology in a proportion that determines the dust content in the salt charge is not more than 50%. Thus, the process of dust utilization in industrial volumes is very problematic due to its significant labor intensity, energy and capital intensity, as well as the lack of efficient high-performance and small-sized briquetting equipment. Dust has an increased moisture capacity and, given out from the mine in the total volume of "raw salt", increases the degree of salt caking, which leads to its hanging in damping tanks and sticking in the overload nodes, and ultimately to malfunctions of the entire salt processing complex. The efficiency of the transport link of the salt processing complex is reduced due to the need to issue from the mine and supply to the factory both a useful product and production waste - dust. Due to the fact that the process of removing dust with a sufficient degree of efficiency occurs at an ambient temperature of at least +18 o C and its relative humidity of not more than 39%, with the method of salt processing under consideration, certain difficulties arise in terms of creating and maintaining the specified microclimatic conditions. 3. The need to erect large and capital-intensive building structures on the surface to accommodate process equipment, buffer and storage tanks in accordance with the specified salt processing process. The purpose of the present invention is to increase the efficiency of the processing and transport stages of the complex, reduce operating and capital costs, as well as reduce the negative impact of the salt processing process on the environment. This goal is achieved in the following way. Unlike analogue processing of salt is carried out in two stages. The first stage is produced underground, while the process equipment is placed directly in the waste treatment chamber. It should be noted that the development of this chamber used for salt processing is carried out taking into account the space-planning solution for the placement of technological equipment, i.e. ledges, which are used as natural support structures for equipment as much as possible. Technological operations are performed in the chamber, including screening, crushing, grinding and classification of salt with the release of at least two useful products (hereinafter referred to as products) of salt processing (for example, a finished product with a fraction of 2.5 to 4.5 mm and an intermediate product with a fraction from 0.2 to 2.5 mm) and production waste - dust (fraction from 0.00 to 0.20 mm). The two products are sent in a streaming mode to an accumulating multi-section buffer warehouse with isolated sections, located in a waste treatment chamber adjacent to the salt processing chamber. Dust is transported in a streaming mode to one of the used cleaning chambers either for storage or for laying this cleaning chamber using a special technology in order to increase the stability of the inter-chamber pillars, or for other types of its disposal. From the buffer warehouse, two products are simultaneously transported by in-line transport as part of two parallel technological lines to the mine cargo table and then by one cargo two-vessel lifting unit - to the daylight surface. The second, final stage of salt processing is carried out on the surface in the factory building, where, similarly to the first stage, two products are fed simultaneously. It should be noted that during the simultaneous transportation of two products of underground salt processing, each of the two in-line parallel technological transport lines, both in the mine and on the surface, is loaded with one of the two products, and each of the two vessels of the mine hoist is also loaded with one of the two products. In the factory building, the finished product (for example, with a fraction of 2.5 to 4.5 mm) is packaged and sent either to the warehouse or to the consumer. The dedusted intermediate product (for example, with a fraction from 0.2 to 2.5 mm) is finally classified with the separation of several products of different granulometric composition, packaged and also sent either to the warehouse or to the consumer. The implementation of the proposed salt processing method allows to completely avoid or minimize the disadvantages inherent in the analogue, and achieve a high end result. 1. A mine microclimate with a relatively constant positive air temperature and its relative humidity not exceeding the critical limit (75%), at which moisture is absorbed by salt, makes it possible to provide conditions for sufficiently efficient and high-quality salt processing, including its classification. At the same time, operating costs associated with providing microclimatic conditions in the salt processing chamber are sharply reduced. 2. The salt separated during the classification process with a fraction of 0 to 0.2 mm, which is considered a waste of production and has an increased degree of caking, can either be stored directly in the mine or used for backfilling spent treatment chambers without loading the continuous-cyclic transport of salt. The latter can be effectively used to dispense only useful products, i.e. dedusted salt. Ultimately, the unit cost of finished products is reduced. 3. Placement of this production in underground conditions, especially crushing and grinding, screening and main classification stages, which are sources of intense dust formation, does not violate the ecology of the environment, and also eliminates the possibility of salt caking when it is in storage and buffer tanks. 4. Underground waste treatment chambers are used as natural building structures to accommodate process equipment and storage (buffer) facilities, as a result of which capital costs for the construction of a salt processing complex are sharply reduced. At the same time, operating costs associated with heating and ventilation of these treatment chambers are not taken into account when determining the cost of production, since in any case they are ventilated, like other mine workings, with heated air due to general mine depression. 5. Due to the fact that the main stages of the salt processing complex are located underground, much smaller construction areas are required for the construction of the factory building on the day surface, which, among other things, is very important in conditions that are limited by the general plan. 6. The rhythm of the work of the entire salt processing complex is increasing due to the minimization of the possibility of emergency downtime of transport lines due to freezing and sticking of salt in bunkers and transshipment units, since a fraction from 0 to 0.2 mm is excluded from the transported products, which has the main , crucial for salt caking. The drawing shows a schematic diagram of a salt processing complex, where 1 is a cleaning chamber, 2 is a panel conveyor, 3 is a main conveyor, 4.5 is an inclined conveyor, 6 is a salt processing chamber, 7 is a storage of "raw" salt, 8,9,10 - in-line transport, 11 - intermediate buffer storage, 12.13 - transport conveyor line, 14 - damping tank, 15.16 - dispenser, 17.18 - lifting vessel, 19 - two-section receiving hopper, 20 - shaft building, 21.22 - conveyor, 23 - salt reloading building, 24 - transport line, 25 - salt loading building, 26,27 - main conveyor transport, 28 - salt sorting and packaging building. It is possible to implement the present invention in the following way. The salt mined in the treatment chambers 1 by a combine method is reloaded through salt discharges onto panel conveyors 2. At the same time, one panel conveyor is installed in each of the treatment chambers that are in simultaneous mining. Panel conveyors provide unloading of "crude" salt with a fraction from 0 mm to 150 mm to the main conveyor 3, which transports it to an inclined conveyor 4, located directly at the salt processing chamber. From the inclined conveyor 4, the "raw" salt is reloaded onto the second inclined conveyor 5, which ensures its transportation directly to the salt processing chamber 6. unloading the conveyor 4 to the intermediate storage of "crude" salt 7, bypassing the conveyor 5, as well as loading the conveyor 5 with salt from this warehouse. In the processing chamber, the initial "crude" salt with a fraction from 0 to 150 mm is screened along a separation boundary of 4.5 mm. The oversize screening product with a fraction of 4.5 to 150 mm is crushed and crushed (for example, in hammer mills and roller mills) to a fraction of 0 to 4.5 mm and, together with the undersize screening product with a similar fraction, is sent for classification. Classification is carried out (for example, on vibrating screens) according to a multistage scheme, sequentially along two separation boundaries: 2.5 and 0.2 mm. As a result of classification according to the separation boundary of 2.5 mm, two products are distinguished: oversize, with a fraction from 2.5 to 4.5 mm; under grate, fraction from 0 to 2.5 mm. The undersize product is classified according to the second separation boundary of 0.2 mm, as a result of which two more products are isolated: oversize, with a fraction from 0.2 to 2.5 mm; undersize fraction from 0 to 0.2 mm. The undersize product with a fraction of 0 to 0.2 mm is a waste product, as it worsens the consumer and physical properties of salt (in particular, it increases the ability of salt to caking). Its in-line transport 8 is sent to the waste treatment chambers for storage and disposal. One of the ways to dispose of this product, which has an increased moisture capacity and caking ability, is to use it for backfilling the mined-out space in the cleaning chamber, which increases the stability of the inter-chamber pillars, and therefore increases the degree of safety when mining in an underground mine and its service life. Oversize products of classification with fractions from 2.5 to 4.5 mm and from 0.2 to 2.5 mm are sent by in-line transport 9.10 to an intermediate buffer warehouse 11. The warehouse is made in the form of a multi-section tank with vertical isolated sections, the number of which is at least two sections. In the outlet part of each section, at least two feeders are installed, which ensure the unloading of salt from the section in the direction opposite to each other during their alternating operation. This achieves the possibility of transferring salt in a flexible way to one, any of the two parallel transport conveyor lines 12,13, as well as minimizing the size of the "dead" zones of the hopper, i.e. increasing the capacity utilization factor. Parallel conveyor lines 12,13 provide simultaneous transportation of two products of salt processing warehouse 11 in the intermediate damping tank 14, located at the mine vertical cargo shaft. Damping capacity 14 is made in the form of a hopper with two sections isolated from each other. Each section of the container 14 provides for receiving salt from only one of the two conveyor lines. Salt is unloaded from tank sections using feeders installed one for each section into a loading weighing device consisting of two dispensers 15,16. Each of the two dispensers ensures that the salt is loaded into a specifically designated lifting vessel 17,18 of the double-ended shaft lifting installation. As a result, it is possible to simultaneously deliver two products of underground salt processing to the surface by one mine cargo lifting unit. On the surface of the mine, salt is unloaded from the lifting vessels 17,18 into a two-section receiving hopper 19 located in the overhead building 20, and each of the vessels 17,18 is unloaded into a section specially defined for it. The outlet of each section of the hopper 19 is equipped with a feeder that unloads onto one of two parallel conveyors 21,22. Using the latter, further simultaneous transportation of two products is carried out to the salt transfer building 23, in which the possibility of transferring the products in the following directions is provided: to the transport line 24, which supplies one of the two products to the housing 25 for shipment of salt in bulk to rail or road transport. In this case, the second product enters the main conveyor transport 26 or 27; simultaneously both products on parallel main conveyor transport 26.27. Using the latter, two products are simultaneously transported to the sorting and packaging building 28. In the housing 28, the second, final stage of salt processing is carried out. Thus, seeded salt with a fraction of 2.5 to 4.5 mm, which is a finished product, is packaged and shipped either to the consumer or to a storage warehouse. The second, intermediate product of salt processing with a fraction from 0.2 to 2.5 mm is classified sequentially into fractions from 1.2 to 2.5 mm, from 0.8 to 1.2 mm, from 0.2 to 0.8 mm with using, for example, vibrating screens. The products obtained as a result of the final classification are shipped either to the consumer or to a storage warehouse.
Claim
1. A method for processing rock salt, which includes the operations of screening, crushing, grinding, classifying and packing salt, characterized in that salt processing is carried out in two stages, while the first stage of salt processing is carried out underground in a salt processing chamber, where the initial "crude" salt is screened along the separation boundary of 4.5 mm, the oversize product is crushed and crushed in sequential order with a fraction of more than 4.5 mm to a fraction of 0 - 4.5 mm, the salt is classified with a fraction of 0 - 4.5 mm along the separation boundary 2, 5 mm, a fraction of 0 - 0.2 mm is separated from the undersize screening product with a fraction of 0 - 2.5 mm in the course of the subsequent classification operation along the separation boundary of 0.2 mm and sent by stream transport to the waste treatment chambers for storage or disposal, and two oversize product classification with fractions of 2.5 - 4.5 mm and 0.2 - 2.5 mm are transported in a streaming mode to an intermediate multi-section buffer warehouse, from which they are simultaneously transported ported by two parallel production lines to the mine cargo shaft, through which, using one two-vessel lifting unit, two products are delivered to the day surface, transported by two parallel production lines to one of the factory buildings, where, at the second stage of salt processing, the product with a fraction of 2.5 - 4.5 mm is packed, and the product with a fraction of 0.2 - 2.5 mm is classified into fractions of 1.2 - 2.5 mm, 0.8 - 1.2 mm, 0.2 - 0.8 mm and packed. 2. The method according to claim 1, characterized in that a fraction of 0 - 0.2 mm is used directly in the mine for laying waste treatment chambers to increase the stability of the inter-chamber pillars. 3. The method according to claim 1, characterized in that the issuance of two products of underground salt processing from the mine at the same time is carried out using one two-vessel lifting unit, each of the vessels is loaded with one of the two products. 4. The method according to claim 1, characterized in that for the simultaneous transportation of two products of underground salt processing, both in the mine and on the surface, two parallel flow technological lines are used, each of which is loaded with one of the two products.
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The invention relates to the field of industrial processing of rock salt and bringing its particle size distribution to consumer standards
1. Rock technical salt- mined in mines at great depths, natural layers of rock salt deposits are developed using special machines, the salt is crushed and rises to the surface, where it subsequently undergoes special processing and grinding into small fractions. Mined from great depths, rock salt is the most environmentally friendly among all existing types of technical salt. Very often, in mines with developed salt layers, specialized sanatoriums are arranged for the treatment of the respiratory tract, since air saturated with salt vapor is very useful for humans.
2. Self-planting technical salt- or lake salt. This salt is in the form of layers at the bottom of lakes and is the main source of salt production in the Russian Federation. Self-planting salt is obtained by natural evaporation of saline solutions obtained by dissolving salt layers close to the earth's surface with water. Basically, the extraction of self-planting technical salt is carried out in salt lakes. The most important place for the production of self-planting salt in Russia is Lake Baskunchak. When collecting salt from the bottom of lakes, various equipment is used: scrapers, tractor loaders, bulldozers, salt pumps and milling combines.
3. Career technical salt- technical salt with the lowest degree of purification. The content of the main chemical element sodium chloride (NaCl2) does not exceed 90%. Usually dirty gray or reddish in color. It can be mined both from the bottom of salt lakes and in rock salt mines. Due to the fact that in its composition it has a large percentage of water-insoluble particles in the form of grains of sand and silt residues, it cannot be used as salt for boiler rooms. Since the cost of quarry salt is lower than that of technical rock or self-planting salt, quarry salt has found wide application as an anti-icing material and is widely used by road services as a means of dealing with ice.
4. Evaporated salt- table salt obtained from brines by evaporation. To obtain it, brines of salt lakes that do not give self-setting, waters of salty springs, underground salty waters, brines extracted using boreholes, and solutions formed by dissolving rock salt layers at their place of occurrence are used.
5. Salt frozen- Extraction of salt from concentrated brines is possible by crystallization of salt during cooling of the brine. In winter, at low temperatures, sodium chloride dihydrate NaCl-2H20 freezes out of saturated brines. Its crystallization is the more intense, the lower the temperature, up to the temperature of the release of cryohydrate (-21.2 °). If the dihydrate is extracted from the brine, then when the air temperature rises above +0.16 ° C, it decomposes and turns into pure table salt.
6. Garden salt- evaporate sea or salty lake water in special pools. The presence of chloride is 94 - 98%, which is less than in other varieties of salt. Again, in garden salt there are much more other ions, because of this, her taste is slightly different.
7. Receipt salt from brines by salting it out with magnesium chloride or calcium chloride. The advantages of these methods lie in the relative simplicity of the technological process (which consists in mixing brines, separating the precipitated salt crystals and drying them), in the absence of fuel consumption for brine evaporation, in the absence of the need for preliminary purification of the brine, etc.
8. Developed rock salt recrystallization methods, allowing to obtain pure salt in a cheaper way than by vacuum evaporation. For example, rock salt is mixed with the mother liquor remaining after secondary crystallization. Salt pulp is stirred with live steam, the condensation of which leads to the dissolution of salt crystals at 100-105°C. The undissolved part containing impurities (anhydrite, etc.) is separated in a settling tank, and the hot solution is sent for crystallization in two stages - when it is cooled to 80°C, then to 50°C. Salt from the crystallizers is squeezed out in centrifuges and dried.
9. More pure edible salt can be achieved waste dissolution, chemical purification of the obtained brine and vacuum evaporation him and also waste flotation. The latter method has an advantage over vacuum evaporation because it does not require steam consumption. Impurities are floated from the waste, and not the main product—the so-called reverse flotation. (Possible and direct flotation in the presence of salts of lead or bismuth) Although flotation gives a product with a high content of NaCl (99.7%), but it is contaminated with photoreagents and has an unsatisfactory appearance, as it is not a colorless (reddish) thin powder (the content of the class 0.15 mm is ~57%).
The EcoTechprom-South company provides services for the removal and processing of industrial chemical waste. Utilization of metal salts is carried out qualitatively and professionally, in compliance with all sanitary rules.
Metal salts are crystalline substances with different solubility in water. They are formed at oil and gas, metallurgical, chemical enterprises, as well as in mines and quarries for the extraction of polymetallic ores. The compounds are contained in the waste of galvanic production, in waste industrial and laboratory waters, and are present in the sludge of sewage treatment plants of industrial enterprises. All these business entities need our services for the removal and disposal of salts.
Salt disposal methods
Salt waste has a negative impact on the environment. They cannot simply be taken to landfills. Hazardous substances evaporate into the atmosphere, penetrate into water sources, and are absorbed by plant roots. They enter the human body together with inhaled air, water, food and can lead to various chronic diseases.
Salt waste is disposed of in 2 ways:
- neutralization and subsequent disposal;
- processing for the purpose of obtaining secondary raw materials.
Neutralization is a physico-chemical method of processing, which consists in the precipitation of salts and filtration. The resulting sediment is sent for disposal in special maps of solid waste landfills, and the filtrate is sent for treatment.
Methods for processing metal salts into mineral fertilizers and building materials are more profitable and efficient. For example, the technology of waste encapsulation using technically modified sulfur. This natural polymer, when heated, reacts with salts of heavy metals, which leads to the formation of environmentally friendly sulfides. The compounds obtained are in the form of granules and are used for the manufacture of sulfur concrete.
A known method of evaporating salt from wastewater in the production of electrolytic Nickel. After drying, the precipitate, consisting of sulfate and sodium chloride, is returned to the technological process again.
Benefits of cooperation with Ecotekhprom-South
We work on a contract basis, we have a state license for the processing of chemical waste of all hazard classes. If necessary, special polymer containers are provided to customers for collecting salts. Thanks to the presence of a large fleet of vehicles, waste is transported quickly and safely. The prices for our services are affordable for both large enterprises and small organizations. The cost of salt processing depends on the state of aggregation of the material, the remoteness of the customer's facility, and the volume of waste to be disposed of. The specialists who work in our company are highly qualified, responsibly and with knowledge of all the technical nuances approach the solution of the tasks.
Call Ecotechprom-South and we will ensure regular removal of salts and their safe disposal.
