The invention relates to the production of sodium chlorate, widely used in various industries. Electrolysis of sodium chloride solution is carried out first in chlorine diaphragm electrolyzers. The resulting chloride-alkaline solutions and electrolytic chlorine gas are mixed to produce a chloride-chlorate solution. The resulting solution is mixed with the mother liquor of the crystallization stage and sent to non-diaphragm electrolysis, followed by evaporation of chloride-chlorate solutions and crystallization of sodium chlorate. The products of diaphragm electrolysis can be partially removed to produce hydrochloric acid from chlorine gas for acidification of chlorate electrolysis and the use of chloride-alkaline solutions for irrigation of sanitary columns. The technical result is a reduction in energy consumption and the possibility of organizing autonomous production. 1 salary.
The invention relates to the production of sodium chlorate, widely used in various industries. World production of sodium chlorate reaches several hundred thousand tons per year. Sodium chlorate is used to produce chlorine dioxide (bleach), potassium chlorate (Berthollet salt), calcium and magnesium chlorates (defoliants), sodium perchlorate (an intermediate for the production of solid rocket fuel), in metallurgy for the processing of uranium ore, etc. There is a known method for producing sodium chlorate by a chemical method, in which solutions of sodium hydroxide are subjected to chlorination to produce sodium chlorate. In terms of its technical and economic indicators, the chemical method does not withstand competition with the electrochemical method, therefore, at present it is practically not used (L.M. Yakimenko “Production of chlorine, caustic soda and inorganic chlorine products”, Moscow, from “Chemistry”, 1974, p. . 366). There is a known method for producing sodium chlorate by electrolysis of a sodium chloride solution in a cascade of diaphragm-less electrolyzers to produce chloride-chlorate solutions, from which crystalline sodium chlorate is isolated by evaporation and crystallization (K. Wihner, L. Kuchler "Chemische Technologie", Bd.1, "Anorganische Technologie", s.729, Munchen, 1970; L.M. Yakimenko, T. A. Seryshev "Electrochemical synthesis of inorganic compounds, Moscow, from "Chemistry", 1984, pp. 35-70). to the proposed invention. The main technological stage, diaphragm-free electrolysis of sodium chloride solutions, occurs with a current output of 85-87%. The process is carried out on ruthenium oxide anodes at a temperature of 70-80 o C, pH 7 with constant acidification of the electrolyte with a 10% solution. hydrochloric acid. Before entering the solid product separation stage, the electrolyte is alkalized to an excess of alkali of 1 g/l with the addition of a reducing agent to destroy the corrosive sodium hypochlorite, which is always present in the electrolysis products. A side anodic process during the electrolysis of chloride solutions is the release of Cl 2 , which not only reduces the current output, but also requires purification of electrolysis gases in sanitary columns irrigated with an alkali solution. The implementation of the process is therefore associated with a significant consumption of hydrochloric acid and alkali: for 1 ton of sodium chlorate, ~120 kg of 31% hydrochloric acid and 44 kg of 100% NaOH are consumed. For the same reason, chlorate production is organized where there is chlorine electrolysis, supplying caustic soda and electrolytic chlorine and hydrogen for the synthesis of hydrochloric acid, while there is often a need for autonomous production of sodium chlorate at points remote from chlorine production. But even where chlorine production and chlorate electrolysis are located nearby, when chlorine electrolysis is stopped and turned off for one reason or another, a forced shutdown of chlorate electrolysis occurs,
Thus, the known method has significant disadvantages: high energy costs (not very high current output) and the impossibility of organizing autonomous production. The objective of the present invention is to create a method for producing sodium chlorate by electrolysis of sodium chloride solutions with reduced energy costs. The problem is solved by the proposed method, in which sodium chloride is first processed in chlorine diaphragm electrolyzers to produce gaseous chlorine gas and electrolytic liquors of composition 120-140 g/l NaOH and 160-180 g/l NaCl, which are then fully or partially subjected to interaction between itself to obtain a chloride-chlorate solution of 50-60 g/l NaClO 3 and 250-270 g/l NaCl, sent for non-diaphragm electrolysis. The process of chlorate non-diaphragm electrolysis is carried out with acidification with hydrochloric acid. The resulting chlorate solution, which also contains sodium chloride, is sent to the stage of evaporation and then crystallization of the chlorate. The mother liquor from the crystallization stage, together with the reaction products of alkali and chlorine from diaphragm electrolysis, is sent to non-diaphragm chlorate electrolysis. Before entering the solid product separation stage, the electrolyte is alkalized to an excess of alkali of 1 g/l with the addition of a reducing agent to destroy sodium hypochlorite. In the partial removal of electrolysis products from chlorine diaphragm electrolyzers, chlorine is used to produce hydrochloric acid, which is used to acidify chlorate electrolysis, and alkali is used to irrigate sanitary columns when cleaning electrolysis gases. With this scheme, 30-35 g of sodium chloride out of 300-310 g contained in each liter of the original solution is processed under chlorine electrolysis conditions. This scheme causes a reduction in energy costs, because The current output of chlorine electrolysis is higher, and the voltage on the electrolyzers is lower than in chlorate electrolysis, and when carrying out the partial electrochemical oxidation of sodium chloride into chlorate under the conditions of chlorine electrolysis, the performance of the entire process as a whole is improved. In addition, when using the described scheme, the cost of cooling the electrolysis is reduced, since chlorine electrolyzers do not require cooling. Note that a deeper activation of chloride under chlorine electrolysis conditions than specified (about 10%) leads to the impossibility of balancing the technological scheme for chlorides, chlorates and water and therefore does not make sense. Within the framework of the proposed scheme, it is possible to obtain an additional effect when feeding solutions with an increased NaClO 3 concentration to chlorate electrolysis, obtained from alkali solutions that are more concentrated in NaOH than diaphragm liquors, for the chlorination of which chlorine containing inerts can be utilized. The electrolyte of chlorine electrolysis can be mixed with chlorine gas not completely, but partially. In this case, part of the electrolytic lyes of diaphragm electrolysis, not intended for chlorination, is allocated for use in sanitary columns, and an equivalent part of the electrolytic chlorine can be used for the synthesis of hydrochloric acid. Directing electrolytes from diaphragm electrolyzers to sanitary columns, and electrolytic chlorine gas to produce hydrochloric acid, solves the problem of autonomous chlorate production, since the supply of alkali and acid from outside will no longer be required. The proportion of sodium chloride processed in chlorine electrolysers is determined by whether the resulting products will be used only to obtain chloride-chlorate liquors as a result of their interaction, after mixing with the mother liquor from the crystallization stage to diaphragm-less electrolysis, or whether the electrolytes of chlorine electrolyzers will be used only for alkalization, and electrolytic chlorine - for the synthesis of perchloric acid for acidification in the chlorate electrolysis scheme, or part of the products will be used in one direction, and part in the other. The advantages of the proposed method are:
1) reduction in energy costs due to the initial stage of electrolysis with a higher current output and at a lower voltage than in conventional chlorate electrolysis: current output is 92-94% and a voltage of 3.2 V in chlorine electrolysis versus 85-90% and 3 .4 V and higher, respectively, in chlorate;
2) the possibility of obtaining, simultaneously with the main product - sodium chlorate - alkaline solutions required according to the technological scheme for alkalization and irrigation of sanitary columns;
3) the possibility of using chlorine produced in chlorine electrolyzers to produce hydrochloric acid on site for acidification of chlorate electrolysis. Example
In an experimental electrolyzer, chlorine diaphragm electrolysis of a sodium chloride solution with a concentration of 300 g/l is carried out on ruthenium oxide anodes at a current density of 1000 A/m 2 and a temperature of 90 o C. The resulting electrolytic liquors contain 140 g/l NaOH and 175 g/l NaCl , mixed with anode chlorine gas and a chloride-chlorate solution of 270 g/l NaCl and 50 g/l NaClO 3 is obtained. This solution is further fed to diaphragmless chlorate electrolysis, carried out in a cascade of 4 electrolysers with ruthenium oxide anodes at a current density of 1000 A/m 2 and a temperature of 80 o C to obtain a final solution of the following composition: 105 g/l NaCl and 390 g/l NaClO3. Thus, from one 1 liter of initial chloride solution, taking into account a 10% reduction in the volume of the solution due to the entrainment of water vapor with electrolysis gases and evaporation of 355 g of sodium chlorate, of which 50 g (14.1%) was obtained after mixing the products of chlorine diaphragm electrolysis , and 305 (85.9%) were produced in the process of chlorate electrolysis. The voltage across the chlorine electrolyzer was 3.3 V with a current efficiency of 93%. The average voltage across the chlorate electrolyzer was 3.4 V with a current efficiency of 85%. Specific energy consumption W (kWh/t. Thus, the reduction in energy costs was 12.1%.
FORMULA OF THE INVENTION
1. A method for producing sodium chlorate by electrolysis of a sodium chloride solution followed by evaporation of chloride-chlorate solutions and crystallization of sodium chlorate with the return of the mother liquor of the crystallization stage to the process, characterized in that the electrolysis of the sodium chloride solution is first carried out in chlorine diaphragm electrolyzers to obtain alkali-chloride solutions and electrolytic chlorine gas, which are mixed to produce a chloride-chlorate solution and sent, after mixing with the mother liquor of the crystallization stage, to diaphragm-free electrolysis. 2. The method according to claim 1, characterized in that the products of diaphragm electrolysis are partially withdrawn to produce hydrochloric acid from chlorine gas for acidification of chlorate electrolysis and the use of chloride-alkaline solutions for irrigation of sanitary columns.Cl(=O)=O]
Sodium chlorate- an inorganic compound, a salt of sodium metal and perchloric acid with the formula NaClO 3, colorless crystals, highly soluble in water.
Receipt
- Sodium chlorate is prepared by the action of perchloric acid on sodium carbonate:
texvc not found; See math/README for setup help.): \mathsf(Na_2CO_3 + 2\ HClO_3\ \xrightarrow(\ )\ 2\ NaClO_3 + H_2O + CO_2\uparrow )
- or by passing chlorine through a concentrated sodium hydroxide solution while heating:
texvc not found; See math/README for setup help.): \mathsf(6\ NaOH + 3\ Cl_2\ \xrightarrow(\ )\ NaClO_3 + 5\ NaCl + 3\ H_2O )
- Electrolysis of aqueous solutions of sodium chloride:
texvc not found; See math/README for setup help.): \mathsf(6\ NaCl + 3\ H_2O \ \xrightarrow(e^-)\ NaClO_3 + 5\ NaCl + 3\ H_2\uparrow )
Physical properties
Sodium chlorate - colorless crystals of cubic system, space group P 2 1 3 , cell parameters a= 0.6568 nm, Z = 4.
At 230-255°C it goes into another phase, at 255-260°C it goes into the monoclinic phase.
Chemical properties
- Disproportions when heated:
texvc not found; See math/README for setup help.): \mathsf(10\ NaClO_3 \ \xrightarrow(390-520^oC)\ 6\ NaClO_4 + 4\ NaCl + 3\ O_2\uparrow )
- Sodium chlorate is a strong oxidizing agent; in the solid state, when mixed with carbon, sulfur and other reducing agents, it detonates when heated or impacted.
Application
- Sodium chlorate has found use in pyrotechnics.
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Literature
- Chemical Encyclopedia / Editorial Board: Knunyants I.L. and others. - M.: Soviet Encyclopedia, 1992. - T. 3. - 639 p. - ISBN 5-82270-039-8.
- Chemist's Handbook / Editorial Board: Nikolsky B.P. and others. - 2nd ed., rev. - M.-L.: Chemistry, 1966. - T. 1. - 1072 p.
- Chemist's Handbook / Editorial Board: Nikolsky B.P. and others. - 3rd ed., rev. - L.: Chemistry, 1971. - T. 2. - 1168 p.
- Ripan R., Ceteanu I. Inorganic chemistry. Chemistry of metals. - M.: Mir, 1971. - T. 1. - 561 p.
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Excerpt characterizing Sodium Chlorate
– Well, where did you “walk”, Madonna Isidora? – my tormentor asked in a feignedly sweet voice.– I wanted to visit my daughter, Your Holiness. But I couldn't...
I didn't care what he thought or whether my "outing" made him angry. My soul hovered far away, in the amazing White City, which showed me the East, and everything around me seemed distant and miserable. But, unfortunately, Caraffa did not allow me to go into dreams for a long time... Immediately sensing my changed mood, “Holiness” panicked.
– Did they let you into Meteora, Madonna Isidora? – Karaffa asked as calmly as possible.
I knew that in his heart he was simply “burning”, wanting to get an answer faster, and I decided to torment him until he told me where my father was now.
– Does it matter, Your Holiness? After all, my father is with you, from whom you can ask everything that naturally I will not answer. Or have you not yet had time to interrogate him enough?
– I do not advise you to talk to me in such a tone, Isidora. His fate will largely depend on how you intend to behave. Therefore, try to be more polite.
“How would you behave if, instead of mine, your father, Holiness, was here?” I asked, trying to change the topic that had become dangerous.
– If my father was a HERETIC, I would burn him at the stake! – Caraffa answered completely calmly.
What kind of soul did this “holy” man have?!.. And did he even have one?.. What then was there to talk about strangers, if he could answer this about his own father?..
“Yes, I was in Meteora, Your Holiness, and I really regret that I will never go there again...” I answered sincerely.
- Were you really kicked out of there too, Isidora? – Caraffa laughed in surprise.
– No, Holiness, I was invited to stay. I left on my own...
- This can’t be! There is no such person who would not want to stay there, Isidora!
- Well, why? And my father, Holiness?
“I don’t believe he was allowed to.” I think he should have left. It's just that his time is probably up. Or the Gift was not strong enough.
It seemed to me that he was trying, at all costs, to convince himself of what he really wanted to believe.
“Not all people love only themselves, you know...” I said sadly. – There is something more important than power or strength. There is still Love in the world...
Karaffa waved me off like an annoying fly, as if I had just said some complete nonsense...
– Love doesn’t rule the world, Isidora, but I want to rule it!
“A person can do anything... until he starts trying, Your Holiness,” I couldn’t resist, “biting.”
And remembering something that she definitely wanted to know about, she asked:
– Tell me, Your Holiness, do you know the truth about Jesus and Magdalene?
– Do you mean that they lived in Meteora? – I nodded. - Well, of course! That was the first thing I asked them!
“How is this possible?!..” I asked, stunned. – Did you also know that they were not Jews? – Caraffa nodded again. – But you don’t talk about this anywhere?.. Nobody knows about it! But what about the TRUTH, Your Holiness?!..
“Don’t make me laugh, Isidora!” Karaffa laughed sincerely. – You are a real child! Who needs your “truth”?.. A crowd that has never looked for it?!.. No, my dear, Truth is needed only by a handful of thinkers, and the crowd should simply “believe”, well, but in what - this no longer matters meanings. The main thing is that people obey. And what is presented to them is already secondary. TRUTH is dangerous, Isidora. Where the Truth is revealed, doubts appear, well, and where doubts arise, war begins... I am waging MY war, Isidora, and so far it gives me true pleasure! The world has always been based on lies, you see... The main thing is that this lie should be interesting enough so that it can lead “narrow-minded” minds... And believe me, Isidora, if at the same time you begin to prove to the crowd the real Truth that refutes them “faith” in who knows what, you will be torn apart by this same crowd...
– Is it really possible for such an intelligent person as Your Holiness to arrange such self-betrayal?.. You burn innocent people, hiding behind the name of this same slandered, and equally innocent God? How can you lie so shamelessly, Your Holiness?!..
Sodium perchlorate is a colorless and odorless crystalline substance. It is hygroscopic and forms several crystalline hydrates. From a chemical point of view, it is a sodium salt of perchloric acid. Not flammable, but has a toxic effect. The chemical formula of sodium perchlorate is NaClO 4.
Receipt
The described substance can be obtained either chemically or electrochemically. In the first case, the usual exchange reaction between perchloric acid and sodium hydroxide or carbonate is usually used. Thermal decomposition of sodium chlorate is also possible. At 400-600 °C it forms sodium perchlorate and sodium chloride. But this method is quite dangerous, since there is a threat of explosion during the reaction.
Theoretically, it is possible to carry out chemical oxidation of sodium chlorate. The most effective oxidizing agent in this case will be lead (IV) oxide in an acidic environment. Typically, perchloric acid is added to the reaction mixture.
Most often in industry they use the electrochemical method. It produces a cleaner product and is generally more effective. The same raw material is sodium chlorate, which produces perchlorate when oxidized on a platinum anode. To make the process more economical, sodium chlorate is produced using cheaper graphite-type electrodes. There is also a promising method for producing sodium perchlorate in one stage. Lead peroxide is used as an anode here.
Mechanisms of electrochemical production
The mechanism of oxidation of chlorate into perchlorate has not yet been fully studied; there are only assumptions regarding it. Research is still ongoing.
The most reasonable option is based on the assumption of electron donation at the anode of the chlorate ion (ClO 3 -), as a result of which the ClO 3 radical is formed. This in turn reacts with water to form perchlorate.
This assumption is expressed in a number of authoritative scientific works. It is also confirmed by the results of studies of the oxidation of chlorates to perchlorates in aqueous solutions labeled with heavy oxygen isotopes 18 O. It was found that 18 O is first included in the composition of chlorate and only then, during the oxidative process, becomes part of the perchlorate ion. But it must be taken into account that changing the anode material (for example, from platinum to graphite) can also change the reaction mechanism.
The second option for the process is the oxidation of chlorate ions with oxygen, which is formed when the hydroxide ion donates electrons.
According to this option, the reaction rate directly depends on the concentration of chlorate in the electrolyte, i.e., as its concentration decreases, the rate should increase.
There is also an option based on the simultaneous donation of electrons by both the chlorate ion and the hydroxide ion. The radicals formed as a result of the reactions are highly active and are oxidized by oxygen, which is released from OH -.
Physical properties
Sodium perchlorate is very soluble in water. Its solubility is much greater than that of other perchlorates. For this reason, in the production of perchlorates, sodium perchlorate is first obtained, and then, if necessary, it is converted into other salts of perchloric acid. It is also highly soluble in liquid ammonia, acetone, hydrogen peroxide, ethanol and ethylene glycol.
As mentioned above, it is hygroscopic, and upon hydrolysis, sodium perchlorate forms crystalline hydrates (mono- and dihydrates). May also form solvates with other compounds. At a temperature of 482 °C it melts with decomposition into sodium chloride and oxygen. When using additives of sodium peroxide, manganese (IV) oxide, cobalt (II, III) oxide, the decomposition temperature is reduced to 150-200 °C.
Chemical properties
The sodium salt of perchloric acid is a very strong oxidizing agent, so much so that it oxidizes many organic substances to carbon dioxide and water.
Perchlorate ion can be detected by reaction with ammonium salts. When the mixture is calcined, the following reaction occurs:
3NaClO4 + 8NH 4 NO 3 → 3KCl + 4N 2 + 8HNO 3 + 12H 2 O.
Another detection method is the potassium exchange reaction. Potassium perchlorate is much less soluble in water, so it will precipitate.
NaClO 4 + KCl → KClO 4 ↓ + NaCl.
It can form complex compounds with other perchlorates: Na 2, Na, Na.
Application
Due to the formation of crystalline hydrates, the use of sodium perchlorate is extremely difficult. It is mainly used as a herbicide, although recently it is used less and less. Almost all sodium perchlorate is converted into other perchlorates (for example, potassium or ammonium) or perchloric acid and is used in the synthesis of many other compounds due to its strong oxidizing properties. It can also be used in analytical chemistry for the determination and precipitation of potassium, rubidium and cesium cations, both from aqueous and alcoholic solutions.
The thermal decomposition of all perchlorates releases oxygen. Thanks to this, salts can be used as a source of oxygen in rocket engines. Some perchlorates can be used in explosives. Potassium perchlorate is used medicinally to treat hyperthyroidism. This disease is caused by increased function of the thyroid gland, and any perchlorate has the property of reducing the activity of this gland, which is necessary to bring the body back to normal.
Danger
Sodium perchlorate itself is non-flammable, but when interacting with certain other substances it can cause a fire or explosion. In a fire, it may release toxic gases or vapors (chlorine or chloroxides). Extinguishing can be done with water.
Sodium perchlorate practically does not evaporate at room temperature, but when sprayed, it can enter the body. Inhaling it causes coughing and irritation of the mucous membranes. Upon contact with the skin, redness appears. As first aid, it is recommended to wash affected areas with copious amounts of soap and water, and also remove contaminated clothing. With prolonged exposure to the body, it enters the blood and leads to the formation of methemoglobin.
When animals (in particular rodents) were administered 0.1 g of sodium perchlorate, their reflex excitability increased, convulsions and tetanus appeared. After administration of 0.22 g, the rats died after 10 hours. When the same dose was administered to pigeons, they showed only mild symptoms of poisoning, but died after 18 hours. This suggests that sodium perchlorate administration develops very slowly.
GOST 12257-93
Group L17
INTERSTATE STANDARD
SODIUM CHLORATE TECHNICAL
Specifications
Sodium chlorate for industrial use. Specifications
OKP 21 4722
Date of introduction 1996-01-01
Preface
1 DEVELOPED BY MTK 89
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Protocol N 3-93 of 02/17/93)
The following voted for adoption:
State name | Name of the national standardization body |
Republic of Azerbaijan | Azgosstandart |
Republic of Armenia | Armgosstandard |
Republic of Belarus | Belstandart |
Republic of Moldova | Moldovastandard |
Russian Federation | Gosstandart of Russia |
Turkmenistan | Turkmengosstandard |
Republic of Uzbekistan | Uzgosstandart |
Ukraine | State Standard of Ukraine |
3 By Decree of the Committee of the Russian Federation on Standardization, Metrology and Certification dated December 23, 1994 N 349, the interstate standard GOST 12257-93 “Technical sodium chlorate. Technical conditions” was put into effect directly as a state standard of the Russian Federation on January 1, 1996.
4 INSTEAD GOST 12257-77
1 AREA OF APPLICATION
1 AREA OF APPLICATION
This standard applies to technical sodium chlorate (sodium chlorate), intended for the production of magnesium chlorate, highly effective oxidizing agents and bleaching compounds.
Formula NaClO.
Relative molecular weight (according to international relative atomic masses 1987) - 106.44.
2 REGULATORY REFERENCES
This standard uses references to the following standards:
GOST 12.1.007-76 SSBT. Harmful substances. Classification and general safety requirements
GOST 1770-74 Laboratory glassware. Cylinders, beakers, flasks, test tubes. Specifications
GOST 2517-85 Oil and petroleum products. Sampling methods
GOST 2603-79 Reagents. Acetone. Specifications
GOST 3118-77 Reagents. Hydrochloric acid. Specifications
GOST 4148-78 Reagents. Iron (II) sulfate 7-hydrate. Specifications
GOST 4204-77 Reagents. Sulfuric acid. Specifications
GOST 4212-76 Reagents. Preparation of solutions for colorimetric and nephelometric analysis
GOST 4220-75 Reagents. Potassium dichromate. Specifications
GOST 4517-87 Reagents. Methods for preparing auxiliary reagents and solutions used in analysis
GOST 5044-79 Thin-walled steel drums for chemical products. Specifications
GOST 6552-80 Reagents. Phosphoric acid. Specifications
GOST 6709-72 Reagents. Distilled water. Specifications
GOST 7313-75 Enamels XB-785 and varnish XB-784. Specifications
GOST 9078-84 Flat pallets. General technical conditions
GOST 9147-80 Porcelain laboratory utensils and equipment. Specifications
GOST 9557-87 Flat wooden pallet measuring 800x1200 mm. Specifications
GOST 9570-84 Box and rack pallets. General technical conditions
GOST 10555-75 Reagents and highly pure substances. Colorimetric methods for determining the content of iron impurities
GOST 10671.5-74 Reagents. Methods for determining sulfate impurities
GOST 10931-74 Reagents. Sodium molybdate acid 2-water. Specifications
GOST 14192-77 * Marking of goods
________________
GOST 14192-96
GOST 17811-78 Polyethylene bags for chemical products. Specifications
GOST 19433-88 Dangerous goods. Classification and labeling
GOST 20490-75 Reagents. Potassium permanganate. Specifications
GOST 21650-76 Means for fastening packaged cargo in transport packages. General requirements
GOST 24104-88 * Laboratory scales for general purpose and standard. General technical conditions
________________
* GOST R 53228-2008 is in force on the territory of the Russian Federation, hereinafter in the text. - Database manufacturer's note.
GOST 24597-81 Packages of packaged cargo. Main parameters and dimensions
GOST 26663-85 Transport packages. Formation using packaging tools. General technical requirements
GOST 27025-86 Reagents. General test instructions
GOST 29169-91 Laboratory glassware. Single mark pipettes
GOST 29208.1-91 Technical sodium chlorate. Method for determining the mass fraction of substances insoluble in water
GOST 29208.2-91 Technical sodium chlorate. Gravity method for determining moisture
GOST 29208.3-91 Technical sodium chlorate. Mercurimetric method for determining the mass fraction of chloride
GOST 29208.4-91 Technical sodium chlorate. Titrimetric method for determining the mass fraction of chlorate using dichromate
GOST 29228-91 Graduated pipettes. Part 2. Graduated pipettes without set waiting time
GOST 29252-91 Burettes. Part 2. Burettes without waiting time
3 TECHNICAL REQUIREMENTS
3.1 Technical sodium chlorate must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.
3.2 Technical sodium chlorate is produced in solid (fine-crystalline powder from white to yellow) and liquid (solution or pulp) form.
3.3 Liquid sodium chlorate is produced in two grades A and B.
Sodium chlorate grade A is used to produce chlorine dioxide using a waste-free method, grade B is used to produce magnesium chlorate, highly effective oxidizing agents and bleaching compounds.
3.4 In terms of chemical indicators, technical sodium chlorate must comply with the requirements and standards specified in Table 1.
Table 1
Indicator name | Standard for sodium chlorate |
||
solid | |||
grade A | brand B |
||
1 Mass fraction of sodium chlorate, %, not less | |||
2 Mass fraction of water, %, no more | Not standardized |
||
3 Mass fraction of chlorides in terms of NaCl, %, no more | |||
4 Mass fraction of sulfates (SO), %, no more | |||
5 Mass fraction of chromate (CrO), %, no more | |||
6 Mass fraction of water-insoluble substances, %, no more | |||
7 Mass fraction of iron (Fe), %, no more | |||
Note - The limits of impurities in a liquid product are given in terms of 100% product |
|||
3.5 Marking
3.5.1 Special stencils must be applied to the tank in accordance with the rules for the transportation of goods in force in railway transport, part 2, section 41, 1976.
3.5.2. Transport marking - in accordance with GOST 14192 with the application of handling signs “Sealed packaging” on drums, “Keep away from heat” on bags.
3.5.3 Marking characterizing the transport hazard of the cargo - in accordance with GOST 19433 with a danger sign corresponding to the classification code 5112 (class 5, subclass 5.1, drawing number 5), UN serial number 1495 for a solid product and 2428 for a liquid product.
3.5.4 Labeling characterizing packaged products must contain:
- product name;
- gross and net weight (for bags - only net weight);
A deviation of ±2% of the actual weight from the nominal weight indicated in the marking is allowed.
3.6 Packaging
Solid sodium chlorate is packaged in liner bags made of polyethylene film with a thickness of at least 0.100 mm, enclosed in: drums according to GOST 5044 made of galvanized steel, version B with a hatch diameter of 300 mm or version B, with a capacity of 50-100 dm3, or drums painted inside and outside with perchlorovinyl varnish according to GOST 7313; in polyethylene bags M10-0.220 according to GOST 17811, enclosed in bags made of chlorine fabric or fire-resistant textile bags.
Insert bags, bags made of chlorine fabric and fire-resistant textile bags are manufactured according to regulatory and technical documentation approved in the prescribed manner.
By agreement with the consumer, it is allowed to pack solid sodium chlorate in plastic bags M10-0.220 in accordance with GOST 17811.
Plastic bags are sealed. Chlorine and fireproof bags are sewn up by machine without gripping the plastic bag.
Product weight in the bag - (50±1) kg.
Solid sodium chlorate is not allowed to get between plastic and fabric bags, as well as on the outer surface of the container.
4 SAFETY AND ENVIRONMENTAL PROTECTION REQUIREMENTS
4.1 Sodium chlorate is toxic. Once in the human body, it causes the breakdown of red blood cells, vomiting, gastrointestinal disorders, and kidney damage. The maximum permissible concentration in the water of reservoirs for sanitary water use is 20 mg/dm, in the air of the working area 5 mg/m (3rd hazard class according to GOST 12.1.007).
4.2 Sodium chlorate is a strong oxidizing agent.
4.3 Sodium chlorate is a non-flammable explosive substance. When heated to a temperature exceeding the melting point (255 ° C), it begins to decompose. At temperatures above 600 °C, decomposition is accompanied by the release of oxygen and can cause an explosion. Mixtures of the product with flammable substances and mineral acids are explosive and may spontaneously ignite due to increased temperature, impact and friction.
4.4 Production premises must be equipped with supply and exhaust ventilation. Equipment, pipelines, fittings must be sealed. Sampling sites and dust-producing sites must be equipped with local suction. Relevant equipment and pipelines must be protected from static electricity and explosion-proof.
4.5 For personal protection of personnel, special clothing must be used in accordance with standard standards and individual respiratory and eye protection equipment: a gas mask of grade B or BKF, a respirator (when working with solid sodium chlorate), goggles.
4.6 If the product gets on your clothing, you must change it immediately. Sodium chlorate is washed off from the skin and mucous membranes with soap and water or baking soda. If sodium chlorate gets inside, induce vomiting, rinse the stomach and provide medical assistance. Special clothing should be washed after each shift.
4.7 In case of spillage of a liquid product or spillage of a solid product, it is necessary to collect it with a vinyl plastic or titanium scoop into a bucket made of vinyl plastic or titanium and wash the spill or spillage area with water. To remove the product, use a tool made of non-sparking material.
4.8 Cleaning the premises using wet or vacuum cleaning.
4.9 In case of fire, extinguish with water.
4.10 Solid waste must be burned in a special area outside the plant. Liquid waste is sent for neutralization of wastewater and into the sewer system for chemically contaminated wastewater. Gas emissions are diluted with inert gas, cleaned of chlorine and released into the atmosphere.
5 ACCEPTANCE
5.1 Sodium chlorate is taken in batches. A batch is considered to be a quantity of a product that is uniform in its quality indicators, accompanied by one quality document, or each tank.
The quality document must contain:
- name of the manufacturer and (or) its trademark;
- name of the product, its brand (for a liquid product);
- batch number and date of manufacture;
- number of containers in the batch;
- gross and net weight;
- classification code of the group according to GOST 19433;
- results of analyzes performed or confirmation of compliance of the quality of sodium chlorate with the requirements of this standard;
- designation of this standard.
5.2 The mass fraction of sulfates is determined by the manufacturer at the request of the consumer.
5.3 To check the compliance of the quality of the product with the requirements of this standard, the sample volume of the product is 10% of packaging units, but not less than three units or each tank.
5.4 If unsatisfactory analysis results are obtained for at least one of the indicators, a repeat analysis is carried out on a double sample or a newly selected sample from the tank.
The results of the re-analysis apply to the entire batch.
6 METHODS OF ANALYSIS
6.1 Sampling
6.1.1 Point samples of solid sodium chlorate are taken with a non-ferrous metal probe, immersing it to 2/3 of the depth of the drum or bag along the vertical axis. Sampling with a scoop from the stream is allowed. The mass of a spot sample must be at least 200 g.
6.1.2 Samples are taken from the tank according to GOST 2517. In this case, before sampling, liquid sodium chlorate is heated and stirred. The heating temperature should be from 60 to 80 °C. The volume of a spot sample must be at least 1 dm.
6.1.3 Spot samples are combined together, mixed and an average sample of a solid product weighing at least 250 g and a liquid product with a volume of at least 0.5 dm3 is taken. An average sample of the product is placed in a clean, dry glass jar with a ground stopper or a polyethylene jar with a screw cap. It is allowed to place an average sample of the solid product in a plastic film bag, which is sealed.
A label is placed on the jar or bag indicating the name of the product (its brand), batch (tank) number, sampling date and the name of the person who took the sample.
6.2 Liquid sample preparation
Before analysis, a sample of the liquid product is heated to a temperature of (80±5) °C and placed in pre-weighed cups for weighing in accordance with GOST 25336. The cups are closed, cooled and weighed again to determine the mass of the liquid product sample.
6.3 General instructions for conducting analysis - according to GOST 27025.
It is permitted to use other measuring instruments with metrological characteristics and equipment with technical characteristics no worse, as well as reagents of no lower quality than those specified.
Rounding of analysis results to the decimal place specified in the technical requirements table.
6.4 Determination of mass fraction of sodium chlorate
6.4.1 Hardware
Laboratory scales of the 2nd accuracy class according to GOST 24104 with the largest weighing limit of 200 g.
Burette according to GOST 29252 with a capacity of 50 cm.
Measuring flask according to GOST 1770 version 1 or 2 with a capacity of 500 cm.
Conical flask type Kn according to GOST 25336, version 1 or 2, capacity 250 cm.
Pipette according to GOST 29228 with a capacity of 10 cm.
Pipette according to GOST 29169 with a capacity of 10 and 25 cm.
Weighing cup according to GOST 25336
6.4.2 Reagents
Distilled water according to GOST 6709.
Iron (II) sulfate, 7-water according to GOST 4148, solution of molar concentration (FeSO 7HO) = 0.1 mol/dm, is prepared as follows: 28 g of iron sulfate is dissolved in 500 cm of water, to which 100 cm of concentrated water is carefully added sulfuric acid. Then dilute with water to 1 dm and, if necessary, filter.
Potassium permanganate according to GOST 20490, solution of molar concentration (KMnO) = 0.1 mol/dm, prepared according to GOST 25794.2.
Phosphoric acid according to GOST 6552.
Sulfuric acid according to GOST 4204.
Sodium molybdate acid according to GOST 10931, solution with mass fraction
6.4.3 Conducting analysis
1.3-1.7 g of solid or 2.5 cm of liquid product prepared according to paragraph 4.2 is weighed, recording the weighing result in grams with four decimal places. A sample of the product is transferred quantitatively into a volumetric flask, dissolved in water, the volume of the solution in the flask is adjusted to the mark with water and mixed.
10 cm of the resulting solution is pipetted into a conical flask, then pipetted with 25 cm of ferrous sulfate solution, 6 cm of sulfuric acid, 5 cm of orthophosphoric acid, 3-5 drops of sodium molybdate solution, mix the contents of the flask and titrate with a solution of potassium permanganate until a slightly pink color .
At the same time, a control experiment is carried out under the same conditions with the same volumes of reagents.
6.4.4 Processing results
The mass fraction of sodium chlorate,%, is calculated using the formula
where is the volume of a solution of potassium permanganate with a molar concentration of exactly 0.1 mol/dm3, consumed for titration in the control experiment, cm;
- the volume of a solution of potassium permanganate with a molar concentration of exactly 0.1 mol/dm3, consumed for titrating the sample, cm;
0.001774 - mass of sodium chlorate corresponding to 1 cm of potassium permanganate solution with a molar concentration of exactly 0.1 mol/dm, g;
- weight of a sample of the product (for a solid product in terms of dry matter), g.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.3% with a confidence probability of 0.95.
The permissible absolute total error of the analysis result is ±0.9% (for a solid product) and ±0.5% (for a liquid product) with a confidence level of 0.95.
It is allowed to determine the mass fraction of sodium chlorate according to GOST 29208.4. When analyzing a liquid product, take 5 cm of a sample prepared by
6.5 Determination of mass fraction of water
The mass fraction of water is determined according to GOST 29208.2.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.08% with a confidence probability of 0.95.
The permissible absolute total error of the analysis result is ±0.08% with a confidence probability of 0.95.
6.6 Determination of the mass fraction of chlorides in terms of NaCl
The mass fraction of chlorides is determined according to GOST 29208.3.
When analyzing a liquid product, take 10 cm of a sample prepared according to 6.2.
The mass fraction of chlorides in a liquid product in terms of sodium chloride (NaCl), %, is calculated using the formula
Where
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.05% with a confidence probability of 0.95.
The permissible absolute total error of the analysis result is ±0.05% with a confidence probability of 0.95.
6.7 Determination of mass fraction of sulfates
6.7.1 Hardware
Laboratory scales of the 3rd accuracy class according to GOST 24104 with the largest weighing limit of 500 g.
Photoelectric colorimeter.
Measuring flasks according to GOST 1770, version 1 or 2, with a capacity of 25 and 500 cm.
Pipettes according to GOST 29228 with a capacity of 1 and 5 cm.
Pipettes according to GOST 29169 with a capacity of 5 and 10 cm.
Weighing cup according to GOST 25336 SV 34/12 or SN 34/12, or SN 45/13.
6.7.2 Reagents
Distilled water according to GOST 6709.
Barium chloride, a solution with a mass fraction of 20%, is prepared according to GOST 4517.
Hydrochloric acid according to GOST 3118, solution with a mass fraction of 10%.
Soluble starch, solution with a mass fraction of 1%, is prepared according to GOST 4517.
A solution containing sulfates is prepared according to GOST 4212.
A solution with a mass concentration of sulfates of 0.01 mg/cm is prepared by appropriate dilution. The diluted solution is used freshly prepared.
6.7.3 Construction of a calibration graph
The calibration curve is constructed according to GOST 10671.5, using volumetric flasks with a capacity of 25 cm.
6.7.4 Conducting analysis
14.5-15.5 g of solid or 3 cm of liquid prepared according to 6.2 are weighed, recording the result in grams to two decimal places. A sample of the product is transferred quantitatively into a 500 cm3 volumetric flask, dissolved in water, the volume of the solution in the flask is adjusted to the mark with water and mixed thoroughly.
10 cm of the resulting solution (for a solid product) or 5 cm of the resulting solution (for a liquid product) is pipetted into a 25 cm volumetric flask, add 1 cm of hydrochloric acid solution, 3 cm of starch solution, 3 cm of barium chloride solution, mix thoroughly. Then stir periodically every 10 minutes. Next, the analysis is carried out according to GOST 10671.
6.7.5 Processing results
The mass fraction of sulfates, %, is calculated using the formulas for the solid product
for liquid product
where is the mass of sulfates found from the calibration curve, mg;
- mass of the product sample, g;
- mass fraction of sodium chlorate in the liquid product, determined at 6.4,%.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.003% (for a solid product) and 0.05% (for a liquid product) with a confidence level of 0.95.
The permissible absolute total error of the analysis result is ±0.003% (for a solid product) and ±0.05% (for a liquid product) with a confidence level of 0.95.
6.8 Determination of the mass fraction of chromates
6.8.1 Hardware
Laboratory scales of the 2nd and 3rd accuracy classes according to GOST 24104 with the largest weighing limit of 200 and 500 g, respectively.
Photoelectric colorimeter.
Measuring flasks according to GOST 1770, version 1 or 2, with a capacity of 25 cm, 100 cm and 1 dm.
Pipettes according to GOST 29228 with a capacity of 1, 5, 10 cm.
Pipette according to GOST 29169 with a capacity of 10 cm.
Weighing cup according to GOST 25336 SV 34/12 or SN 34/12, or SN 45/13.
6.8.2 Reagents
Acetone according to GOST 2603.
Distilled water according to GOST 6709.
Diphenylcarbazide, a solution of a mass concentration of 2.5 g/dm in acetone, is prepared as follows: (0.2500 ± 0.0002) g of diphenylcarbazide is dissolved in 100 cm of acetone. The solution is stored in a dark glass bottle.
Potassium dichromate according to GOST 4220.
Sulfuric acid according to GOST 4204, solution molar concentration (HSO) = 5 mol/dm.
A solution containing chromium (VI) is prepared according to GOST 4212. By appropriate dilution, prepare a solution containing 0.001 mg of chromium (VI) per 1 cm3. The diluted solution is used freshly prepared
6.8.3 Construction of a calibration graph
Reference solutions are prepared as follows.
Add 2.0 to five volumetric flasks with a capacity of 25 cm; 4.0; 6.0; 8.0; 10.0 cm of a diluted solution of potassium dichromate, which corresponds to 0.002; 0.004; 0.006; 0.008 and 0.010 mg chromium (VI).
Add 1 cm of sulfuric acid solution and 1 cm of diphenylcarbazide solution to each flask, adjust the solution volumes to the mark with water and mix.
At the same time, prepare a control solution that does not contain chromium.
After 2 minutes, measure the optical densities of the reference solutions relative to the control solution on a photoelectrocolorimeter at a wavelength of 540 nm, using a cuvette with a light-absorbing layer thickness of 20 mm.
Based on the data obtained, a calibration graph is constructed, plotting the introduced mass of chromium in milligrams on the abscissa axis, and the corresponding optical density value on the ordinate axis.
6.8.4 Conducting analysis
6.0-7.0 g of solid product or 3 cm of liquid product of grade A, or 1 cm of liquid product of grade B is weighed, recording the weighing result to two decimal places. Samples of the liquid product must be prepared in accordance with 6.2.
The sample is quantitatively transferred into a volumetric flask with a capacity of 1 dm3 (for solid and liquid product grade B) and a capacity of 100 cm3 (for liquid product grade A). Fill the volume of the solution in the flask with water to the mark and mix.
10 cm of the resulting solution is pipetted into a 25 cm volumetric flask and then the analysis is carried out in the same way as when constructing a calibration graph.
6.8.5 Processing results
The mass fraction of chromates,%, is calculated using the formulas
for solid product
for liquid product grade A
for liquid product grade B
where is the mass of chromium found from the calibration curve, mg;
- mass of the product sample, g;
2.23 - conversion factor of Cr to CrO;
- mass fraction of sodium chlorate in the liquid product, determined at 6.4,%.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.002% for a solid product, 0.0003% for a liquid product of grade A and 0.01% for a liquid product of grade B with a confidence probability of 0 .95.
The permissible absolute total error of the analysis result is ±0.002% for a solid product, ±0.0003% for a liquid product of grade A and ±0.03% for a liquid product of grade B with a confidence level of 0.95.
6.9 Determination of the mass fraction of water-insoluble substances
The mass fraction of water-insoluble substances is determined according to GOST 29208.1. When analyzing a liquid product, take 40 cm of a sample prepared according to 6.2.
The mass fraction of water-insoluble substances in a liquid product, %, is calculated using the formula
where is the mass of the filter crucible together with the residue, g;
- mass of the filter crucible, g;
- mass of sample for analysis, g;
- mass fraction of sodium chlorate in the liquid product, determined at 6.4,%.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.003% for a solid product and 0.01% for a liquid product.
The permissible absolute total error of the analysis result is ±0.003% for a solid product and ±0.01% for a liquid product.
6.10 Determination of the mass fraction of iron Watch glass.
A sample of the product is transferred quantitatively into a porcelain cup, 20 cm of water and 20 cm of hydrochloric acid solution are added.
The cup is covered with a watch glass and heated in a water bath until the emission of gas bubbles stops. Then the glass is removed, washed over a cup with water, after which the solution in the cup is evaporated to dryness in a water bath.
The residue in the cup is dissolved in 20 cm of water, the solution is transferred to a 100 cm volumetric flask, the volume of the solution in the flask is adjusted to the mark with water and mixed.
20 cm of the resulting solution is pipetted into a 50 cm volumetric flask and then the analysis is carried out according to GOST 10555 using the sulfosalicylic method, without adding hydrochloric acid solution to the analyzed solution
6.10.3 Mass fraction of iron,%, is calculated using formulas for a solid product
for liquid product
where is the mass of iron found from the calibration curve, mg;
- mass of the product sample, g;
- mass fraction of sodium chlorate in the liquid product, determined at 6.4,%.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute discrepancy between which does not exceed the permissible discrepancy equal to 0.0015% with a confidence probability of 0.95.
The permissible absolute total error of the analysis result is ±0.0015% for a solid product and ±0.002% for a liquid product with a confidence level of 0.95.
7 TRANSPORTATION AND STORAGE
7.1 Solid sodium chlorate is transported by rail and road in accordance with the rules for the transportation of goods in force for this type of transport and instructions for ensuring the safety of transportation of dangerous goods by road, approved in the prescribed manner. The product is transported in covered vehicles. By rail - by wagon load.
7.2 Liquid sodium chlorate is transported by rail in special tanks of the consignor (consignee) with a safety cap.
7.2.1 The degree (level) of filling tanks is calculated taking into account the full use of their capacity (carrying capacity) and volumetric expansion of the product with a possible temperature difference along the route.
7.2.2 The product must not come into contact with the outer surface of the tank. If a liquid product gets on the surface of the tank, it must be washed off with copious amounts of water.
7.2.3 Tank filling hatches are sealed with rubber gaskets.
7.3 Solid sodium chlorate must be transported in transport packages formed in accordance with GOST 26663, in drums - on flat pallets in accordance with GOST 9557, in textile bags - on flat pallets made of aluminum or light alloys, manufactured in accordance with the requirements of GOST 9078 and regulatory and technical documentation, approved in the prescribed manner, in plastic bags - in aluminum or light alloy box pallets of a folding design, manufactured in accordance with the requirements of GOST 9570 and regulatory and technical documentation approved in the prescribed manner.
Means for fastening containerized cargo in a package - in accordance with GOST 21650.
The gross weight of the package should not exceed 1 ton.
The dimensions of the package are according to GOST 24597.
It is allowed, by agreement with the consumer, to transport packaged solid sodium chlorate by road in unpackaged form.
7.4 Sodium chlorate in the manufacturer’s packaging is stored in closed special rooms intended for storing explosive goods weighing no more than 200 tons.
Sodium chlorate must not be stored together with flammable substances, ammonia salts and acids.
Liquid sodium chlorate is stored in special containers equipped with air bubblers for mixing and heat exchangers for heating.
8 MANUFACTURER WARRANTY
8.1 The manufacturer guarantees that the quality of sodium chlorate meets the requirements of this standard subject to the conditions of transportation and storage.
8.2 The guaranteed shelf life of solid sodium chlorate is 6 months, liquid - 1 year from the date of manufacture.
Electronic document text
prepared by Kodeks JSC and verified against:
official publication
M.: Standards Publishing House, 1995
Sodium, calcium and magnesium chlorates are still used as non-selective herbicides - for cleaning railway tracks, industrial sites, etc.; as defoliants for cotton harvesting. Acid decomposition of chlorates is used to produce chlorine dioxide “on-site” for bleaching high-strength cellulose.
K2 Unfortunately, a serious disadvantage of this method is the low quality of household disinfectants and bleaches. After the policy of “mandatory standardization” was relaxed, manufacturers of “whiteness” products began to use their own specifications, lowering the hypochlorite content in the product from the standard 5% by weight. up to 3% or less. Now, to obtain the same amount of chlorate with a good yield, it will be necessary not only to consume much more “whiteness” but also to remove most of the water from the solution. Probably the most convenient method may be to pre-concentrate the “whiteness” by partial freezing.
Professional liquid products for neutralizing wastewater on ships contain up to 40% sodium hypochlorite.
K3 Disproportionation of hypochlorite into chloride and chlorate occurs at a high rate at pH
K4 Indeed, a highly efficient power source of significant power for electrolysis is half the success of the matter and a topic for special discussion.
Here I would like to remind you of the need to follow electrical safety rules.
Work related to electrolysis on a large scale is considered particularly dangerous with respect to electric shock. This is due to the fact that contact of the experimenter’s skin with the conductive electrolyte is almost inevitable. The release of gases at the electrodes causes the formation of corrosive electrolyte aerosols, which can settle on electrical components, especially when forced air cooling is used. The consequences can be very sad - from corrosion of metal parts and failure of the power supply to insulation breakdown with mains voltage entering the electrolyzer and all the consequences for the experimenter.
Under no circumstances should high-voltage parts of the installation be installed in the immediate vicinity of the electrolyser. All components of the power source should be located at a sufficient distance from the electrolyzer and in such a way as to completely exclude both the ingress of electrolyte on them in the event of an electrolyzer failure and the deposition of conductive aerosols. In this case, high-current wires from the source to the electrolyzer must have a sufficient cross-section corresponding to the process current. All conductors (and their connections) directly connected to the electrical network must be hermetically sealed with moisture-resistant insulation.
Galvanic isolation of the electrolyzer from the electrical network is required. A conventional transformer provides adequate insulation, but it is strictly forbidden to power the electrolyzer directly from autotransformers such as LATR, etc., since in this case the electrolyzer may be directly connected to the phase wire of the network. However, an LATR (or household autotransformer) can be used to regulate the voltage on the primary winding of the main transformer. You just need to make sure that the power of the LATR is not less than the power of the main transformer.
During long-term operation of the installation, protection of electronic components from overheating and short circuits would be useful. To begin with, it is quite possible to limit yourself to installing a fuse in the primary winding of the transformer at a current corresponding to its rated power. It is also reasonable to supply power to the electrolyser through an appropriate fuse (preferably an adjustable electromagnetic release), keeping in mind that a short circuit in the electrolyser is quite possible.
The question of the need to ground the installation in this case is not so simple. The fact is that in many residential premises there is initially no grounding and it is not easy to arrange it on your own. In some cases, instead of grounding, cunning electricians organize “grounding”, connecting the grounding bus and the network neutral directly at the consumer. In this case, the “grounded” device is directly connected to the current-carrying circuit of the network. In our conditions, we can recommend giving priority to high-quality isolation of the electrolyzer from the network and the experimenter from the entire installation.
Safety rules should not be neglected also for the reason that a long experiment in an amateur laboratory always attracts the attention of other people, whose skills and behavior the experimenter cannot control. Be aware of those around you and work safely.
